BER for BPSK in Rayleigh Channel

March 30, 2018 | Author: ganga_ch1 | Category: Orthogonal Frequency Division Multiplexing, Probability Density Function, Normal Distribution, Modulation, Mimo
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12/9/13BER for BPSK in Rayleigh channel DSP log Google Home About Blog (35 votes, Analog Channel Coding DSP GATE average: 4.46 out of 5) BER for BPSK in Rayleigh channel by Krishna Sankar on August 10, 2008 Modulation OFDM Subscribe MIMO Long back in time we discussed the BER (bit error rate) for BPSK modulation in a simple AWGN channel (time stamps states August 2007). Almost an year back! It high time we discuss the In a brief discussion on Rayleigh channel, wherein we stated that a circularly symmetric complex Gaussian random variable is of the form, , where real and imaginary parts are zero mean independent and identically distributed (iid) Gaussian random variables with mean 0 and variance The magnitude which has a probability density, . is called a Rayleigh random variable. This model, called Rayleigh fading channel model, is reasonable for an environment where there are large number of reflectors. System model The received signal in Rayleigh fading channel is of the form, , where is the received symbol, is complex scaling factor corresponding to Rayleigh multipath channel is the transmitted symbol (taking values +1′s and -1′s) and is the Additive White Gaussian Noise (AWGN) Assumptions 1. The channel is flat fading – In simple terms, it means that the multipath channel has only one tap. So, the convolution operation reduces to a simple multiplication. For a more rigorous discussio to review Chapter 15.3 Signal Time-Spreading from [DIGITAL COMMUNICATIONS: SKLAR] 2. The channel is randomly varying in time – meaning each transmitted symbol gets multiplied by a randomly varying complex number variance 1/2. 3. The noise has the Gaussian probability density function with with 4. The channel and . by the apriori known i.e. . Since is modeling a Rayleigh channel, the real and ima is known at the receiver. Equalization is performed at the receiver by dividing the received symbol where is the additive noise scaled by the channel coefficient. Bit Error Rate The equations listed below refers Chapter 14.3 in [DIGITAL COMMUNICATION: PROAKIS] If you recall, in the post on BER computation in AWGN, the probability of error for transmission of either +1 or -1 is computed by integrating the tail of the Gaussian probability density functio error rate is, www.dsplog.com/2008/08/10/ber-bpsk-rayleigh-channel/ 1/50 12/9/13 BER for BPSK in Rayleigh channel . However in the presence of channel , the effective bit energy to noise ratio is , where . , one must evaluate the conditional probability density function over the probability density function of . . So the bit error probability for a given value of is, To find the error probability over all random values of Probability density function of From our discussion on chi-square random variable, we know that if probability density function of is, . Error probability So the error probability is, . is a Rayleigh distributed random variable, then is chi-square distributed with two degrees of freedom. since Somehow, this equation reduces to . Note: 1. I have not yet figured out the math to reduce the above integral to the answer. If some one knows, kindly drop in a comment. 2. Another way for finding the bit error rate might be to find the pdf of . However, I do not know how to find pdf following the division of two random variables. Simulation Model It will be useful to provide a simple Matlab/Octave example simulating a BPSK transmission and reception in Rayleigh channel. The script performs the following (a) Generate random binary sequence of +1′s and -1′s. (b) Multiply the symbols with the channel and then add white Gaussian noise. (c) At the receiver, equalize (divide) the received symbols with the known channel (d) Perform hard decision decoding and count the bit errors (e) Repeat for multiple values of and plot the simulation and theoretical results. Click here to download Matlab/Octave script for BER computation of BPSK in Rayleigh fading channel Figure: BER plot of BPSK in Rayleigh fading channel www.dsplog.com/2008/08/10/ber-bpsk-rayleigh-channel/ 2/50 12/9/13 BER for BPSK in Rayleigh channel When compared to the AWGN case, around 25dB degradation due to the multipath channel (at the point). This is both good and bad: bad because we need to spend so much energy warming), and good because we signal processing engineers are trying to figure out ways for improving the performance. Reference [DIGITAL COMMUNICATION: PROAKIS] Digital Communications by John Proakis Related posts: BER for BPSK in OFDM with Rayleigh multipath channel Rayleigh multipath channel model Derivation of BPSK BER in Rayleigh channel Deriving PDF of Rayleigh random variable Tagged as: AWGN, PSK, Rayleigh D id you like this article? Make sure that you do not miss a new article by subscribin Subscribing via e-mail entitles you to download the free e-Book on BER of BPSK/QP ► OFDM Simulation ► Channel Simulation ► Phase Modulation { 277 comments… read them below or add one } Simran April 30, 2013 at 10:34 pm hello sir, In ur code, you have written EsN0dB = EbN0dB + 10*log10(nDSC/nFFT) + 10*log10(64/80); Can you pls explain how the third term “10*log10(64/80)” comes?? Reply Krishna Sankar May 4, 2013 at 5:54 am @Simran: The 64/80 is to handle the cyclic prefix in the OFDM symbol. In this case we are assuming that the ofdm symbol is of duration 3.2us and has an extra 0.8us of cyclic pref So the ratio is 3.2us/4us which with 20Msps sampling translates to 64/80. Reply Bai March 9, 2013 at 7:06 pm Hi, why is the rayleigh channel same as the noise channel? i thought the rayleigh channel should be simulated using the rayleigh random variable posted in the other article ? Reply Krishna Sankar March 13, 2013 at 5:43 am @Bai: Rayleigh channel is formed using complex gaussian random variable. http://www.dsplog.com/2008/07/14/rayleigh-multipath-channel/ Reply www.dsplog.com/2008/08/10/ber-bpsk-rayleigh-channel/ 3/50 12/9/13 BER for BPSK in Rayleigh channel hilman February 19, 2013 at 8:12 pm Hi Krishna, You can find the proof of bit error rate formula in David Tse’s book problem 3.1 http://snag.gy/2yRO0.jpg Reply Krishna Sankar February 21, 2013 at 6:15 am @hmilan: thanks Reply xiaofei October 17, 2012 at 12:31 pm relay network with feedback delay over rayleigh fading channel Reply Fan Ding October 11, 2012 at 7:01 am Hi,Khishma you said the PDF of r was :p(r) = 1/(Eb/No)*exp(-r/(Eb/No)) , should it be :p(r) = 1/(r’)*exp(-r/r’) ? where , r’ = E(h^2)*Eb/No ; . . Reply Krishna Sankar October 17, 2012 at 6:15 am @Fan: When trying to look back at the derivation of the BER @ http://www.dsplog.com/2009/01/22/derivation-ber-rayleigh-channel/ could see the following comment – “The resulting BER in a communications system in the presence of a channel h, for any random values of |h|^2, must be calculated evaluating the probability density function of gamma.” Am unable to full recall the details, will ponder on this a bit, and update. Reply Abhijith October 18, 2012 at 2:39 pm Hi Krishna, I derived PDF of SNR in Rayleigh fading channel. How can I share here? It is set of mathematics and if I paste it is not appearing neat. I wish to present equations as you presented in your write up. It is just 8 lines of equations. Please give hints to write equations as you have written. Thank you. Reply Krishna Sankar October 19, 2012 at 5:34 am @Abhijith: You can mail me the pdf/doc and I can share it. OR upload to an online site like dropbox and paste the public url Reply Fan Ding October 11, 2012 at 6:27 am Your posts help me a lot,thks. www.dsplog.com/2008/08/10/ber-bpsk-rayleigh-channel/ 4/50 12/9/13 BER for BPSK in Rayleigh channel And I saw that someone had asked you some questions in Chinese. I am curious that you could read in Chinese.Is that really ? haha Reply Krishna Sankar October 15, 2012 at 6:25 am @Fan: I know as much Chinese as I know Spanish Reply Xie xie payel saha September 21, 2012 at 9:34 pm krishna plz give the code for ber of bpsk over rician channel Reply Krishna Sankar September 22, 2012 at 6:07 am @payel saha: I have not tried modeling rician channel Reply Skm September 16, 2012 at 11:12 am Hi sir, have recently gone through the matlab code for ” BER computation of BPSK in Rayleigh fading channel”. There, after equalization , we perform hard decision decoding by % receiver – hard decision decoding ipHat = real(yHat)>0; which effectively converts all incoming complex signals into 1 having real part greater than zero. That means at this stage we are not utilizing the imaginary part. So my question is, why should we add complex ” noise ” OR complex ” h ” ? as finally we are not utilizing imaginary part of complex signal atall ? Reply Krishna Sankar September 18, 2012 at 5:40 am @Skm: In the BPSK case, as you rightly said we are not using the information on the imaginary dimension and that component is ignored. I added the imaginary part in the simulatio Reply Charly Tchouadou-Ndalleu January 21, 2013 at 4:17 am n = 1/sqrt(2)*[randn(1,N) + j*randn(1,N)]; % white gaussian noise, 0dB variance h = 1/sqrt(2)*[randn(1,N) + j*randn(1,N)]; % Rayleigh channel y = h.*Signal + 10.^(-SNR_db(i)/20)*n; hello Sir! what does those above equations mean? i will very happy if you could explain them as i am to write a code which calculate the BER of OFDM using BPSK. Thanks Reply Krishna Sankar January 23, 2013 at 5:27 am @Charly Tchouadou-Ndalleu: randn generates zero mean unity variance Gaussian distributed random variables. To add on the real and imaginary dimensions, we use variance at unity. The term n is an additive noise (modeling the thermal noise) and h is a multiplicative noise (modeling the phase and amplitude changes introduced by c Reply Abhijith August 6, 2012 at 7:20 pm @Krishna: Thank you very much for your informative articles. I have few questions slightly related to this article. I need your opinion on how you would have approached this scenario. This scenario is hypothetical. Specification: Assume I have to design a communication system for a specific area and specific purpose. My customer specified me minimum BER (QoS) and transmit power. I have liberty to choose re Approach: www.dsplog.com/2008/08/10/ber-bpsk-rayleigh-channel/ 5/50 This line below. Step 2: To meet this BER. Typically. transmit power and receiver n Now depending on whether the system is going to be indoor or outdoor. error correction algorithm. 2012 at 5:09 am @Rupom: what is gamma-gamma channel – any pointers? Reply Aiyu May 22. My question is Q1: How to measure real time channel if I don’t have built communication system? Q2. I have some questions about the commands 1. 2012 at 5:03 am @DHARMESH: The key aspects to look out are – data rate requirement and the range (since it is indoor. Is my approach is right? Q3. I want to know about the energy efficient modulation characteristics i have to consider for choosing these modulation schmes. one can look at typical channel models available in the literature and pick one which can closely match your desired use case. Step 4: Start design and test back. I can find outage probability or Bit error rate. With regards. h is normalized by sqrt(2) to make the average power gain=1. Reply Krishna Sankar July 5. so under these conditions which schemes is more suitable for my application.N)]. To start off.wikipedia. what channel and bandwidth is. Step3: Decide how much Sync you need. This depends on. choose modulation technique and error correction algorithm. So. Doing a channel measurement in the target deployme expensive and time consuming. Using this PDF. the free-space path loss model needs to be tweaked. I don’t know how channel looks like .org/wiki/ZigBee Reply Rupom July 3. Step 1: Measure and model channel: Assume I am able to measure channel. 2012 at 6:12 am @Abhijith: Nice approach. I would have approached this way. Reply Krishna Sankar July 26. % Rayleigh channel www. am I right? h = 1/sqrt(2)*[randn(1. Abhijith Gopalakrishna. 2012 at 11:04 pm How can I do this using “Gamma-Gamma Channel”... thanks for the blog and the MATLAB demo. have I overlooked something. 2012 at 9:34 am hello krishna. assuming a free-space path loss model. Reply Krishna Sankar August 9. Hope this Reply DHARMESH July 24. am assuming that it is of the order of 50meters). Find PDF of the channel somehow. As it is specific place.12/9/13 BER for BPSK in Rayleigh channel Now I have to choose modulation technique. The Zigbee standard seems to enable a cheap and power efficient transceivers http://en.dsplog. based on Channel.N) + j*randn(1. 2012 at 10:14 am Hi Krishna. One would also need to look at the range requirement of the communication link. I am waiting for your inputs. I want to design a transceiver for wireless sensor networks for the application of home automation or for the indoor environment. If I am right. Alternately.com/2008/08/10/ber-bpsk-rayleigh-channel/ 6/50 . Thank you very much. Please help me out. simpler the mo circuits can be cheaper and power efficient. complextoreal.com/2008/06/05/16qam-bit-error-gray-mapping/ Reply filip March 29. 2012 at 4:43 am @pavan: will add to the TO-DO list Reply Ritesh March 2. Es/N0 = k*Eb/N0. hence using 1/20 3.12/9/13 BER for BPSK in Rayleigh channel 2. 2012 at 7:04 pm Hey! Based on what can you assume that channel is known in the receiver? When does the rx obtain this information? I mean channel changes a lot in a very short period. For Eb/N0 you might need to scale by M. the scaling is done on a voltage signal. so my q is basically about justifying how and why Rx knows CSI. 2012 at 5:43 pm hello thank u alot for your notes it was really usefull for me! I am student of ms in system communications engineering would you mind introducing me some fresh. there will be training sequence in the transmission which will help the receiver estimate the channel. 2012 at 2:08 pm hai. 2012 at 5:38 am @filip: In most cases. 3.com/tutorial. yes 2. 2012 at 4:43 am @sayyed: Please have a look at http://www. exciting and excellent topic in wireless communication (esp mimo and stc) for my cem thank u again and excuse me for my bad english Reply Krishna Sankar March 12. This will be a noisy estimate of the channel (which results in Reply sayyed armaghan March 10.dsplog.htm Very nice list of tutorials Reply pavan March 10. what about the case of M-QAM? Let’s say it’s then Es_No_dB instead of Eb_N0_dB. 2012 at 6:46 pm www. do I need to change anything else for y in the equation above??? thank you Reply Krishna Sankar June 11. Thanks Reply Krishna Sankar March 30. so when is the CSI su What I noticed is that the curve obtained here matches the one obtained by the command berfading. where k= log2(M) Please see http://www. 2012 at 5:33 am @Aiyu: replies 1. can you please provide me a source for understanding jakes model… Reply Krishna Sankar March 12. In the line below Why is the SNR divided by 20. Es/N0 should be straight forward.com/2008/08/10/ber-bpsk-rayleigh-channel/ 7/50 .*qamSig + 10^(-Eb_N0_dB(ii)/20)*n. not 10? y = h.dsplog. Will the DPLL degrade or enhance the perfomance of the BER Reply Krishna Sankar February 6. i just want to ask you if you deal with matlab function that creat rayleigh channel >> name (rayleighchan) its a good function . 2012 at 8:36 pm Mr. Reply Colin O'Flynn December 14.com/2008/08/10/ber-bpsk-rayleigh-channel/ 8/50 . 2012 at 6:12 am @Nam: Well.1 (pg 99-101) of the book “Digital Communication Reply Krishna Sankar January 4. 2012 at 6:19 am @ammar: Thanks. Why the theory and the simulation of Rayleigh channel in “ber-bpsk-rayleigh” is same but in ” ber-16qam-rayleigh” is so different? Reply Krishna Sankar January 6. as this is an older post. Reply ammar January 23. 2012 at 6:50 pm Hi Krishna you are a very helpful man . Sankar probably you will be the right person to solve a problem i have encountered in my MTech. Krishna.dsplog. project. 2012 at 6:55 am Hello Mr. 2012 at 5:47 am www. Let us consider a Rayleigh frequency selective fading channel.12/9/13 BER for BPSK in Rayleigh channel Hi Krishna DO you know the codes for the plot of BER for a BPSK modulation in a RICIAN channel? Plz reply asap thanks Reply Krishna Sankar March 5..while using B loop. I do not have the function rayleighchan() handy Reply Nam Nguyen January 5. but a description of the evaluation of that integral is found in section 5. and have a many optional parameter thank you >> i will check your blog daily Reply Krishna Sankar January 26. 2012 at 5:37 am @Ritesh: Have not tried to simulate Rician channel Reply Pranjal Gogoi February 3. In this case how i will calculalte the BER performance.. rather it might be necessitated by any phase errors. 2012 at 5:11 am @Pranjal: Why do you want the DPLL in place? Am sure it’s not because of the channel. the 16QAM is more error prone when compared to BPSK. 2011 at 5:16 am Perhaps you found this out a while back. dsplog. but including the path loss (PL in dB) between two nodes.please sir Reply Krishna Sankar May 23. var = 1/(2*10^(PL/10)).12/9/13 BER for BPSK in Rayleigh channel @Colin: Thanks. 2011 at 2:46 am @shu: My replies: 1/ For QPSK. send data on I channel as well as Q channel 2/ I have not discussed Rician channel model Reply shu May 18. Krishna. 2011 at 12:14 am hi krishna sir I saw ur example of ber -bpsk-rayleigh channel but i need the the qpsk for the rician channel I dont know coding sir so please help me sir give some hints where to change thats enough for Reply Krishna Sankar May 23. Agree? Reply Hassan Moradi August 2. 2010 at 3:32 pm thank you Mr krishna Reply nico October 28. Reply Krishna Sankar November 19. I’m trying to simulate frequency non-selective rayleigh fading channel like you did. the variance became var = 1/(2*10^(PL/20)) Is this correct? Thank you. So instead of having complex number h (channel) with the real and imaginary parts are Gaussian distributed random variable having mean 0 and variance 1/2. 2011 at 3:50 pm Hi sir . 2010 at 1:05 pm Hello Mr. send data on I channel as well as Q channel 2/ I have not discussed Rician channel model Reply Hasan Thiabat December 2.com/2008/08/10/ber-bpsk-rayleigh-channel/ 9/50 . indeed found the derivation. I do not have the book handy. 2010 at 5:53 am @nico: The variance should use factor of 1/10. 2011 at 2:39 am @seshu: My replies: 1/ For QPSK. I think you should use y=|h|x+n instead of using y=hx+n. 2010 at 11:57 am in the expression for y. I saw ur Ber_bpsk_reyleigh program i gone through that link but dont know how to send the data in the qpsk can u please help me and tell some hints about the rician channel. Yes. but will try to get it Reply seshu May 18. Right? Reply www. 2010 at 7:23 am what is meant by a power limited in communication system. 2010 at 6:52 pm I simulate 16QAM modulation (no coding) over Rayleigh channel. 0. chan. so I write: chan = stdchan(1/Rb.dsplog.actually what is tap? & why it should be used in rayleigh channel? Reply www. 2010 at 6:40 pm Thank you for your respone! Reply Rebecca April 13. The channel can distort the phase and amplitude of the transmit signal Reply Tom June 14. hence unable to comment on the stdchan() function. 0. I need your help. -16].2*1e-6. I have not discussed Rician channel Reply dolly April 13.ResetBeforeFiltering = 0. But in general.5*1e-6]. Reply Krishna Sankar June 21. 2010 at 5:52 am @Tom: A system where we cannot transmit very high power (due to battery/size limitations etc) Reply Tuyen Tran June 12. chan. chan. 2010 at 6:00 pm Hi Krishna. 2010 at 4:41 am @Rebecca: Sorry. Do u have any topic related to BER for BPSK in Rician channel? I’d like to know how to write (matlab code) for Rician… Tks. -10.PathDelays = [0.NormalizePathGains = 1. I want to change profile of channel.12/9/13 BER for BPSK in Rayleigh channel Krishna Sankar August 3.AvgPathGaindB = [0. Reply Krishna Sankar April 14. 2010 at 6:10 am @Tuyen Tran: I do not have matlab. -2.’cost207RAx4′). 0. 2010 at 2:53 pm hii sir how to get rayleigh channel using BPSK modulation & adding AWGN noise by usingg taps.4*1e-6. 2010 at 6:02 am @Hassan Moradi: No. could you show me I am wrong or right? Reply Krishna Sankar June 14.150. your code seems to be correct. Make sure that you convolve your time dom Reply Tuyen Tran June 19.com/2008/08/10/ber-bpsk-rayleigh-channel/ 10/50 . chan. 2010 at 5:54 am hey i just had a look on the matlab code that you posted.dsplog.5. 2010 at 4:57 am @Saurabh: What is y? Reply kadir February 18.dsplog..com/2008/07/14/rayleigh-multipath-channel/ b) 3 Tap fixed ISI channel with ZF equalization http://www.cos i am new to matlab and to this topic i have very less knowledge.1 with equal probability s = 2*ip-1. 1 -> 0 correct me if i am wrong.com/2008/08/10/ber-bpsk-rayleigh-channel/ 11/50 .. cheers bijoy Reply Krishna Sankar March 28.12/9/13 BER for BPSK in Rayleigh channel Krishna Sankar April 14. I have similar kind of project to do but in my project prof is asking to plot BER of BPSK i. 2010 at 10:58 pm Hi friend. 2010 at 3:54 pm Can you distinguish clearly correlated and uncorrelated Raykeigh Channel and how are they formed from awgn? How to implement BER simulation for correlated and uncorrelated Rayleig Reply www. we do not have inte as in the BER of BPSK in Rayleigh channel case. Hence the BER is identical. http://www. I do not understand why the BER of BPSK in Rayleigh channel is equal to the BPSK OFDM in Rayleigh channel. Does it look different from when we plot it against Eb/No? Reply Krishna Sankar March 30. 2010 at 4:40 am @dolly: A signal transmitted over air can reach the receiver through different paths.dsplog.com/2009/11/29/ber-bpsk-isi-channel-zero-forcing-equalization/ Reply bijoy babu March 14. In this po I have discussed briefly on a) Rayleigh channel @ http://www. % generating 0. Reply Saurabh February 28.dsplog. Thank you very much. even though we have a 10-tap multipath channel. 2010 at 3:40 pm @bijoy babu: Yes Reply FERNANDO March 9.m % Transmitter ip = rand(1.com/db-install/wp-content/uploads/2008/08/script_ber_bpsk_rayleigh_channel. The gain and phase information corresponding to each path is notionally stored as tap.. i checked the output for n=10 ip =1 0 0 1 0 1 1 1 0 0 s =1 -1 -1 1 -1 1 1 1 -1 -1 please help me out.N)>0. BER vs γ. please. as the channel duration is less than the cyclic prefix (of 16 samples). 2010 at 6:48 am @FERNANDO: In this simulation model. 2010 at 3:42 am hi.e. % BPSK modulation 0 -> -1. Reply Krishna Sankar March 29.. . thanks Reply Krishna Sankar April 4. i have modified your code (rayleigh channel) in order to simulate ricean channel./h. 1 -> 0 s = 2*ip-1. 2010 at 8:53 pm Hi Krishna. it can indeed result in noise amplification… Reply sinto February 4. % BPSK modulation 0 -> -1.. from a quick look it does not seem to be right.12/9/13 BER for BPSK in Rayleigh channel Krishna Sankar March 31. Is it OK to divide y by h as above. Reply Krishna Sankar April 4. 2010 at 5:18 pm hi kishna.com/2008/08/10/ber-bpsk-rayleigh-channel/ 12/50 .N)>0.N) + j*randn(1. how did they get such values? this is exactly my question Reply Sanket February 9.N))) is this code correct? please help me. Reply samta January 19. 2010 at 5:40 am @kadir: AWGN is an additive noise whereas as the channel is a multiplicative noise. 2010 at 4:09 am @Sanket: You are right. the channel varies for each symbol. in book Fundamental of Wireless Communication (by Tse and Viswanath) Rician fading modeled as: h = sqrt(K/(K+1))*line_of_sight_signal + sqrt(1/(K+1))*reflected_and_scattered_signal K = K-factor From the above equation.. I want to have a table of values for channel impulse response to be used for simulating a MIMO system. as it may lead to severe noise amplification as h is a random variable and may take any value? Thanks. of error. how can i generate Rayleigh channel impulse response as ready numbers to be used in a program without using the rand()+j*rand large number of symbols to get the plot of the prob.5. 2010 at 4:21 am @sinto: Well. i would ask you a question regarding the rayleigh channel. some papers do list d transmit and receive antenna to get a MIMO channel matrix. 2010 at 10:34 pm hello mr.while calculating you have used yhat=y. % Rician channel h = 1/sqrt(2)*(sqrt(K/(K+1))*s + sqrt(1/(K+1))*(randn(1. For correlated channel.. % generating 0. the chann Reply samalqudah February 14.1 with equal probability ip = rand(1. 2010 at 8:11 pm Hi Sir. www. krishna. For uncorrelated channel.In your MATLAB program of calculating BER for BPSK in raleigh fading Channel. I have a little query.dsplog. 2009 at 1:16 am Hi How r u ? hope fine. I want to have a table of values for channel impulse response to be used for simulating a MIMO system. we are loading information on subcarriers exp(jwt). Zaffar Reply samalqudah January 11.dsplog. Reply zaffar January 16. so that i can vary pil you please refer my paper and guide me. i would ask you a question regarding the rayleigh channel. if u have QPSK matlab code for BER in Rayleigh channel. krishna.org/stamp/stamp.12/9/13 BER for BPSK in Rayleigh channel I am working in turbo decoding.my recieved signal is effected by AWGN noise and reyleigh fading.com/2008/08/10/ber-bpsk-rayleigh-channel/ 13/50 .named by DIGITAL COMMUNICATION AND SIG hope this will help u and waiting for ur responce. Reply prabag December 7. Whatever u have derieved is for BPSK case. Reply mat_ad December 29.. 2009 at 10:08 pm Hello I am working on a paper in which i am trying to plot ber for bpsk using rayleigh channel. the thing is.dsplog.jsp?arnumber=01437347&tag=1 Reply Krishna Sankar December 7. I need to verify my results using the theoretical formula. but. I have followed the same steps posted by you in “BER for BPSK in Rayleigh channel” to produce the rayleigh output and later used estimated SNR to calculate BER.. i am experiencing constant BER. 2009 at 5:04 am www. Anyways as u asked the full mathematical concept of ur expression of BER for BPSK. 2009 at 5:27 am @prabag: When we are doing IFFT. I m very satisfy to this site.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/ Reply student December 1.ieee. Can you kin channel? I shall be grateful Thanking in advance.Can u derive it or please give me some hint. how can i generate Rayleigh channel impulse response as ready numbers to be used in a program without using the rand()+j*rand large number of symbols to get the plot of the prob.. because it is very helpful to me to make my project. 2010 at 6:31 pm Hi Krishna. exp(j2wt) and so on… you may find a detailed discussion at http://www. but. of error. some papers do list d transmit and receive antenna to get a MIMO channel matrix.so at the receiver there might be a problem in decoding the data Reply Krishna Sankar December 8. We take the fft and look at the fft output prior to attempting demodulation http://www.u can go through my thesis supervisors book. thanks.also when we give 1s and 0s as input to IFFT block the o/p is complex value…and some of the suppose if this is transmitted thro’ severely faded channel still there is a possibility that these signal might get into deep fade. 2009 at 11:52 am Hi I would like to know that how IFFT makes signls to be orthogonally modulated in OFDM. which is in thae same formate which u have taken like hS+W. My problem is that i want the exact expession of probability of error for QPSK.?? http://ieeexplore. we are not going to look at the time domain samples and attempt demodulation. pls send me.com/2008 At the receiver. i need to use estimated SNR including the pilot symbols and noise samples as par equations in the paper.dsplog. I am simulating 16 QAM in a Rayleigh channel and am trying to compute the SER(& BER). how did they get such values? this is exactly my question. 2010 at 6:10 pm hello mr. whether i am in right way. I hope you are doing well. and d’ont Eb_N0_dB(ii)/20 thanks Reply Krishna Sankar December 7. www. I have been able to write the code for coherent detection. I am having difficulty writing the code for non coherent. 2009 at 1:34 am Krishna Pillai. I am told to assume Rayleigh fading channel with BPSK modulation.ieee. Hellos sir. Presently.Use average SNR (complex) from -5 to 20 dB. 2009 at 4:59 am @aissou: The negative sign came as I am scaling the noise voltage. Here is th link http://ieeexplore. due to time constraints I wont be able to help with the coding part.12/9/13 BER for BPSK in Rayleigh channel @student: Sorry. I am keeping the signal swing the same and reducing the swing of noise voltage to simulate various Eb/N0 values. 2009 at 4:39 am @Obinna O: Hope you have finished the project by now.com/2008/08/10/ber-bpsk-rayleigh-channel/ 14/50 . Your figures will include plots from simulation. The posts here are very useful. Good luck. Your ¯g simulation. Please help me resolve this. I got stuck with the silmulation of the imperfect SNR Estimation.org/stamp/stamp.jsp?arnumber=01437347 But. Reply Krishna Sankar December 7. Reply Obinna O November 30. great job. Using MAT-LAB plot bit error probability (BEP) under coherent and non-coherent de-tection.I am working on a IEEE paper “On the Impact of SNR Estimation Error on Adaptive Modulation” .dsplog. Use average SNR (complex) from -5 to 20 dB. 2009 at 7:05 pm Krishna Pillai. 2009 at 4:22 pm 10^(-Eb_N0_dB(ii)/20): help me please wy you used teh signe negatif – in( -Eb_N0_dB(ii)/20). 2009 at 4:22 pm 10^(-Eb_N0_dB(ii)/20): help me please wy you used teh signe negatif – in( -Eb_N0_dB(ii)/20). Hello Sir. Reply usha November 20. 2009 at 5:48 am Hello sir. Using MATLAB plot bit error probability (BEP) under coherent and non-coherent detection when receiver is equipped with three antennas to exploit diversity. and d’ont Eb_N0_dB(ii)/20 thanks Reply aissou December 1. I was asked to assume Rayleigh fading channel with BPSK modulation. Reply aissou December 1. Please assist me in this. thank you so much Reply Obinna O November 26. e.dsplog. And the algorithm you have followed says: Simulation Model (a) Generate random binary sequence of +1’s and -1’s. Reply Krishna Sankar December 6. and then add awgn. Good luck.e. (b) Multiply the symbols with the channel and then add white Gaussian noise. 3.1 i. i am multipying the symbols with covariance matrix to obtain Rayleigh fading channel. Reply bopuhafs November 12. 2009 at 8:53 am www.12/9/13 BER for BPSK in Rayleigh channel I need to plot the fig. My question is. Make hard-decision on the desired signal to get the BER. in the 2nd step. Generate complexed AWGN 4. Do both the simulations yield similar results? Can you please make me understand the difference. due to time constraints.com/2008/08/10/ber-bpsk-rayleigh-channel/ 15/50 . 2009 at 1:24 am hi i was trying to simulate BER for BPSK using Rayleigh fading channel. Generate the independent complexed Gaussian random vectors and multiply them with the corresponding covariance matrix represented by J0(x) (i. I need to follow the steps. For your case. Reply Krishna Sankar December 6. equalize (divide) the received symbols with the known channel (d) Perform hard decision decoding and count the bit errors (e) Repeat for multiple values of and plot the simulation and theoretical results. 2009 at 5:19 am @bopuhafs: To make the noise power to be lower than the signal power Reply Puripong November 8. So. We need to have a) Generate output of channel for desired user by using flat fading independent Rayleigh channel b) Generate output of channel for undesired user by using correlated flat fading Rayeligh channel c) Add (a) and (b). 2009 at 9:06 pm 10^(-Eb_N0_dB(ii)/20) . may I decline to help with the simulation. Estimated SNR vs pdf basing on the theoritical equations stated under imperfect SNR Estimation. Generate BPSK-modulated random data for the desired signal and interfering users. 1. your results will be poorer due to the additional interference from the undesired user. Good luck. 2. and then in step 3. But the difference is.. Jo(2*pi*d) where d is the ratio o wavelength) to get the correlated Rayleigh fading channel. the channel is independent flat fading Rayleigh channel which is applied to a single users transmission and then we add awgn to it. whereas. 2009 at 4:15 pm @Student: In my simulation model. Reply student November 19. its bit more complex. you are multiplying the symbols with the channel and then adding AWGN to it. (c) At the receiver. i am generating AWGN. 2009 at 4:19 pm @usha: Sorry. pourquoi utiliser le moin ‘-’ Reply Krishna Sankar December 3. can u please help me with the simulation ?? Thank You. 2009 at 7:24 pm Hi Krishna I have a problem in my m. 2009 at 9:21 am i m very satisfy to this site. I sent you an email regarding my project.5)*(randn(N. the fading channel by H=sqrt(0. plz refer http://www. Reply Krishna Sankar November 8. If we want t mak sophisticated…. Sara Reply Krishna Sankar November 8.I want you to help me about this problem. the most simplest way would be to keep the same channel for a group of symbols. thank you. I have some question about h. 2009 at 7:39 am @amit: Thanks.1. then use an independent realization for the next group of symbols.I produce a symbol strean by x=randint(N.dsplog. Reply Krishna Sankar November 8.com/2008/08/10/ber-bpsk-rayleigh-channel/ 16/50 .file that i sent to your email.com/2007/11/06/symbol-error-rate-for-4-qam/ Reply Kirankumar Palthi October 21.1)).In this s I think it is not possible in real systems.What should i do if I want to keep the channel fixed in every coherence time of channel?How can i write the m-file of this issue? help me please. Reply amit October 28. I’ a student from Thailand. if u have qpsk matlab code for BER then plz send me . For QPSK.12/9/13 BER for BPSK in Rayleigh channel Hi Krishna Sankar My name is Puripong.M) where M is the order of modulation. I’m looking for the introduction to simulate BER performance in Rayleigh fading channel and this is a very nice post {BER for BPSK in Rayleigh channel}. bcause it is very hepful to me to make mmy project. Reply Sara November 3. 2009 at 8:41 am @Sara: I will take a look. Please reply to that mail. I have not yet discussed that. thank u. I found 25dB degradation when compared to BPSK-AWGN Thank you very much.1)+j*randn(N. 2009 at 7:38 pm Hi Krishna I have a problem in my m. Why does the real and imaginary parts must have variance equal to 1/2 ? Could you give me an explaination or some reference textbooks for this question ? Reply Sara November 3.file. 2009 at 4:21 pm HI Krishna.dsplog. Reply www. Sorry for the delay. 2009 at 8:45 am @Sara: Well. 2009 at 5:51 am www..? plz help me thanks Reply Krishna Sankar October 1. Messerschmitt Reply M_abs September 7. Reply mak_m September 17. 2009 at 5:58 am @mak_m: 1/ Thanks to OFDM. thanks in advance waiting for ur reply Reply Krishna Sankar September 18. 2009 at 6:56 pm @mak_m: I am referring Digital Communication: Third Edition. 2009 at 3:18 pm can u plz tel me how did u drive the formula…for ber of bpsk in rayleigh channel…can i get further explanation can u plz telme the source of it thanks in advance gud work keep it up Reply Krishna Sankar September 10.can u plz tell me which channel model shuld i use so i can show the performance improvement due tel me which channel model shuld i use in case of bpsk without ofdm…ie to degrade the ber of ur simulation.12/9/13 BER for BPSK in Rayleigh channel mak_m September 28. your posts helps me a lot. Reply mak_m September 9.com/2008/08/10/ber-bpsk-rayleigh-channel/ 17/50 .can u plz tell me ray leigh channel used in BER for BPSK(single tap) is different from ber for bpsk ofdm(10tap)… but their but if the ber of bpsk is same as ber of bpsk in ofdm in . even though we have a 10-tap frequency selective channel... Reply Krishna Sankar September 9. the performance for BPSK in a 10 tap channel will be much poorer due to inter symbol interference. Lee. Barry. 2009 at 5:21 am @mak_m: 1/ Yes. Hence the performance of flat fading BPSK is c 2/ If we do not use OFDM. the 10 tap channel is in effect gives same performance as flat fading channel 2/ You can use 10 tap channel with BPSK modulation. Hope this helps. I want to how can i find the BER equation for 16-QAM and QPSK over the RAYLEIGH channel ? please help me…. David G. by John R. 2009 at 9:21 pm thanks . with OFDM. you need to do pulse shaping etc at the transmitter. Edward A.. ihave gone through all the comments but didnt find the answers.. However. then y did we use ofdm . or i shuld use some other code. 2009 at 6:53 pm Dear Krishna Sankar.so i can show can i use the same 10tap model used in ur code for bpskofdm in the case of bpsk only.dsplog. hi krishna can u plz tel me…i m really confused . 2009 at 3:16 am thanks very much for replying i doo agree with ur comment however i dint get my answer yet can u plz tell me the code for channel model for bpsk tht is frequency selective channel (u have done it with flat faing) ? with the help of this i can compare the ber of bpsk with rayleigh as compared to ber of bpsk rayleigh ofdm . each subcarrier experienced a flat fading channel. dsplog. 2009 at 5:44 am @vikas: My replies: 1/ “within coherence time channel coffecients are constant…” [krishna] yes. But the performance is still too far away from that of AWGN. if we have infinite receive antennas.*s + 10^(-Eb_N0_dB(ii)/20)*n.com/2008/06/05/16qam-bit-error-gray-mapping/ Reply vikas September 3. This is both good and bad: bad because we need to spend so much energy to and good because we signal processing engineers are trying to figure out ways for improving the performance.com/2007/12/09/symbol-error-rate-for-16-qam/ http://www. around 25dB degradation due to the multipath channel (at the point). think about (a) Multiple receive antennas. I think ” because we signal processing engineers are trying to figure out ways for improving the performance” can be undestandbe that if channel estimation is perfect. these coefficients remain the same for the cohere Reply lumingui August 11. http://www. However.s). we are having optimal performance. What is the better channel estimation and equ Reply Krishna Sankar August 11.12/9/13 BER for BPSK in Rayleigh channel @M_abs: You may modify the modulated variable s to correspond to QPSK/16QAM respectively.com/2007/11/06/symbol-error-rate-for-4-qam/ http://www. % Rayleigh channel sr = (1/sqrt(nTx))*kron(ones(nTx.within coherence time channel coffecients are constant… if I am correct than why we are multiplying each data bit by rayleigh variable…./h.com/2009/04/13/transmit-beamforming/ (c) Multiple transmit antennas with Space Time Block Coding (STBC) http://www..*exp(-j*angle(h)). 2009 at 12:05 pm ok. 2.com/2008/08/10/ber-bpsk-rayleigh-channel/ 18/50 .1). Make sure that you have the corresponding demodulators too. there is only one rayleigh path.dsplog..dsplog. You may refer http://www.dsplog. 2009 at 10:46 am Hi Krishna.N) + j*randn(nTx. I know the anwser .N)]. channel coefficients are almost the same 2/ “why we are multiplying each data bit by rayleigh variable…. thanks! Reply lumingui August 10. % Channel and noise Noise addition y = h.*sr. in this current simulations where we know the ‘perfect channel’ and equalization.dsplog. 2009 at 4:55 am @lumingui: You are right in saying that. And theoretically. 2009 at 5:14 pm www. 2009 at 6:31 am hi… I have a doubt…. we can try to com closer to that of AWGN.1) + 10^(-Eb_N0_dB(ii)/20)*n. After I read sklar’s book again for fading. y1 = sum(h. “When compared to the AWGN case.” 1. % Channel and noise Noise addition hEff = h.dsplog. What you said is one of solution for it.dsplog. so the channel is flat.com/2008/09/28/maximal-ratio-combining/ Maximal Ratio Combining and bring down the BER by quite a bit.??” [krishna] rayleigh variable corresponds to channel coefficients. % equalization yHat = y. you try to simulate as having a perfect channel estimation and then equalizes it. in your code for “BER for BPSK modulation in a Rayleigh fading channel” . please reply Reply Krishna Sankar September 8.?? h = 1/sqrt(2)*[randn(nTx.com/2008/10/16/alamouti-stbc/ Does this answer your concern? Reply Hemanth July 29. I think we reach close to AWGN performance (b) Multiple transmit antennas with Beamforming http://www. I have a question related to Rayleigh Multipath Channel. right ? So.e. down-converter ? problems with the transmission/reception path I described ? Regards Joel Reply Krishna Pillai July 6. you are getting the theoretical result of a linear d give very poor BER since the phase of the received points is now uniformly distributed and when you use a BPSK. Note that additive noise can result i Reply joel July 2. 2009 at 5:45 am @Hemanth: Some comments: “It stems from the fact that the instantaneous SNR is (|h|^2)Eb/No. Tell me if this Reply Krishna Sankar August 5. then the channel model is x+n’ or utmost kx+n’ where k is real and n’ is Gaussian and using a zfe restores our situation to this model.12/9/13 BER for BPSK in Rayleigh channel Hi Krishna. results in instantaneous SNR of (|h|^2)Eb/No. you would have a only a 50% chance that the transmitted point would b of using an EQ. The most simplest type wont even consider that there was a channel and just do hard decision decoding on the rece but still thats one type of receiver. we started of the d |h|^2Eb/N0. 2009 at 8:56 pm Dear Krishna. Another receiver type. But. 2009 at 10:39 am Hi Krishna.com/2008/08/10/ber-bpsk-rayleigh-channel/ 19/50 . So the structure looks like this : Guard Insertion -> Up-Convertion -> Multipath Channel -> Down-Convertion -> Guard Removal -> Equalizer The problem is that the received signal is disturbed. = E((hx)(x^hh^h)]. Please tell me w Reply Krishna Sankar July 30. When you derived an expression for the average probability of symbol error in a rayleigh channel. xhat = y/h = (h*/|h^2|)y = h*(hx+n)/(|h|^2) = (|h|^2x + n)/(|h|^2) Do you agree? Reply Hemanth July 31. So your statement that the instantaneous SNR is independent of equalizaton is not correct. which does division by the channel h.5*erfc(s derived assuming noise adds only along a single direction. 0.dsplog. “This has been derived assuming noise adds only along a single direction” [krishna] Its a kinda loose sentence. the signal is ideally equalized. even when the EQ is not used” [krishna] We can have different types of receivers. you can see that the signal energy is scaled by a factor of |h|^2. =h(Px)(h^h) =Px(|h|^2) Noise power remains the same as before. I was looking at it in a different way which lead to my confusion. which I am finding difficult to comprehend. what can be resposible for the signal distortion . So. Lets assume that there is no white noise caused by the channel. 2009 at 5:39 am @Hemanth: You are not correct when you mentioned that the theoretical derivation of BER in Rayleigh channel did not include the effect of equalizer.5*erfc(sqrt(gamma)). while the effect of a random channel(with uniform phase distribution) would be to throw the constellation point anyw is 0. I agree with your explanation for where the EQ comes in. Additionaly the transmitted signal will be up-mixed and then down but without the phase imbalance. Since we have no AWGN. Received signal power = E[(hx)(hx)^h](^h is hermittian). you obtained a linear relationship(approximation for higher Eb/N0′s) between the logBER This derivation gives the average BER for a rayleigh channel with no mention of an EQ anywhere in the derivation. Recall that. Note: y = hx + n After equalization. because of which the received SNR is going to be (|h|^2)Eb/No. yes the noise is additive and not multiplicative. is when we say the average BER is obtained by taking an expectation over the ‘old’ expression for a BPSK ber. i. So whether or not you use this kind of a I think where we have used the EQ implicitly. Its onlu after equalization the instantaneous SNR is |h|^2Eb/N0. But when you simulate. and the simulation which uses it. what i dont follow is the gap between the theoretical derivation for average BER with no mention of the effects of an EQ. 2009 at 5:24 pm www. It stems from the fact that the instantaneous SNR i with you on this point ) Since y=hx+n. % repeating x = (sqrt(2)/sqrt(T))*cos(2*pi*freqR. 2009 at 4:35 pm Hi Krishna. % additive white gaussian noise equalization yHat = y.99]. Can you do me a favour to check and find a problem to get them closely? Thanks. %generating the FSK modulated signal % noise n = 1/sqrt(2)*[randn(1.t).5. % sampling instants tR = kron(ones(1. Regards Reply Krishna Pillai July 15.com/2008/08/10/ber-bpsk-rayleigh-channel/ 20/50 . op1 = conv(yHat.12/9/13 BER for BPSK in Rayleigh channel @joel: The multipath channel causes a phase and amplitude distortion to the channel. % repeating the sampling instants Eb_N0_dB = [0:11].theoryBer. I hoped that you negate or confirm my assumptions. I do no see issues with the ch Reply joel July 8.ones(1. % symbol duration t = [0:1/T:0. sqrt(2/T)*cos(2*pi*1*t)). % Rayleigh channel % coherent receiver y = h./h.^(Eb_N0_dB/10))). % counting the number of errors end simBer = nErr/N.N). i.5*erfc(sqrt(10. Since there is no noise.5. % theoretical ber EbN0Lin = 10. that the equalizer removes the multipath distortion by dividing the output by the channel impule response. Reply hugh June 24. % correlating with frequency 2 % demodulation ipHat = [real(op1(T+1:T:end)) < real(op2(T+1:T:end))]. axis([0 11 10^-4 0.5]) grid on legend('theory:AWGN'.e. % generating 0. then the estimated channel will include the effects of multipath + phase rotations which may have occurred.dsplog. xlabel('Eb/No.'r-'. % correlating with frequency 1 op2 = conv(yHat. 2009 at 4:47 am @joel: What you said is probable. theoryBerAWGN = 0.N*T)].N*T) + j*randn(1. %theoretical BER % plot close all figure semilogy(Eb_N0_dB. That has to be removed (aka equalization) prior to demodulation. i dont know tha % Matlab Script for computing the BER for Binary FSK modulation in a Rayleigh fading channel clear N = 10^5 % number of bits or symbols T = 10.T)). But there is some problem inside.*x + 10^(-Eb_N0_dB(ii)/20)*n.2).ipHat]). How are you estimating the channel. the qualization is ideal . hold on semilogy(Eb_N0_dB.N)>0.'theory:fsk-coh'.1 with equal probability freqM = ip+1. they should cling tightly.N*T) + j*randn(1.2). then estimate the channel @ the receiver.N*T)].'LineWidth'. theoryBer = 0.theoryBerAWGN. 2009 at 1:47 am The thing is. 'sim:fsk-coh'). % converting the bits into frequency. % multiple Eb/N0 values for ii = 1:length(Eb_N0_dB) % generating the bits ip = rand(1. Y = introduces additional phase rotation which spoils the equalization. hold on semilogy(Eb_N0_dB. dB') ylabel('Bit Error Rate') title('Bit error probability curve') But why the theory and simulation curves are separated each other. % white gaussian noise. 0dB variance h = 1/sqrt(2)*[randn(1.*tR).*(1-sqrt(EbN0Lin.^(Eb_N0_dB/10). % nErr(ii) = size(find([ip ./(EbN0Lin+2))). bit0 -> frequency of 1. www. I used your script for BER with FSK modulation in AWGN channel and modified to get BER with FSK modulation in Rayleigh channel. bit1 -> frequency of 2 freqR = kron(freqM.simBer. sqrt(2/T)*cos(2*pi*2*t)).'b-'). If you are estimating the channel by defining a known sequence (in frequency domain) at the tra described above.'mx-'). hnorm). every fading coefficient is uncorrelated and affects only 1 bit. is it consider as uncorrelated fast fading? What are some of the ways to estimate the chann Reply Krishna Pillai June 21.:)=y(i+2. can you tell me how to plot the power angular profile for an incoming signal. h=[1 0. there will be a preamble sequence which is known by both transmitter and receiver. Reply Krishna Pillai May 31.:). using which receiver can form an estimate of the channel.but i need a simpler one eventhough it’s too long… i don’t know how to use functions equivelent to those you used with your code…. chanresp(:. for j=1:nsym p=chanipac(:. 2009 at 9:56 am hi krishna. a_vec=reshape(a. so can anyone help me please?? Reply Krishna Pillai May 20.nsubc. I have written a code for modelling OFDM using BPSK where the channel taps are given by h1=1 h2=0. Reply nikitha May 23. Reply Ideal May 26. So. 2009 at 5:27 am In the simulation model above. i need a very simple code using very simole function….j).5). hnorm=h.5 h3=0. SNR=4.3]. am not familiar with modeling angular profile. 2009 at 10:20 pm Dear Krishna. a_fft]. 2009 at 5:45 am @fof: Good luck. chanipac=[a_fft(nsubc-1. for i=1:nsubc cprem(i. 2009 at 12:41 pm @bluray: Yes.j)=conv(p’.:).nsym)). end.. I am unable to figure out th is the code nsubc=4.N)-0. y=chanresp+10^(-SNR/20)*n.it’s a great one…. end. Reply fof May 19. N=nsubc*nsym. nsym=1. 2009 at 8:30 pm @Ideal: Sorry../norm(h).dsplog.3 and i have used awgn channel. www. a_fft(nsubc.12/9/13 BER for BPSK in Rayleigh channel Reply bluray June 18.5 0.nsym)+i*randn(nsubc+4.nsym) a_fft=sqrt(nsubc)*ifft(a_vec). n=1/sqrt(2)*(randn(nsubc+4..:). a=sign(rand(1. 2009 at 12:32 am hi……i saw youe code for alamouti STBC….. this is uncorrelated fast fading Typically. First i would like to thankyou for answering the questions of all the people like me.com/2008/08/10/ber-bpsk-rayleigh-channel/ 21/50 . 2009 at 5:05 am @wafaa: You can just convolve the ofdm time domain signal with the channel taps. i’m modeling a SUI channel. I can think of two approaches . op_vect=2*o-1.com/2008/08/10/ber-bpsk-rayleigh-channel/ 22/50 .2) berrat=ber/N Reply Krishna Pillai May 31. However. there can be lots of permutations possible. Agree? You may use the code in the post http://www. 2009 at 4:33 pm Thank you Krishna for all your efforts. Reply Ahmed April 18. Could you please send source to relay and from relay to destination)outage probability under different relay selection strategy where all the relay nodes are distributed according to homogeneous Poisson point pr Reply www. ber=size(find(a-op).com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/ for reference. Alam April 6. fde=hdiag*o_fft. You may refer to the post on BER for BPSK in O http://www.dsplog. I am working on multi-relay cooperative communication system./hfreq. Reply wafaa May 5.1. hfreqinv=1. 2009 at 8:08 pm @nikitha: I did not probe deeply. 2009 at 8:35 am hello sir if we were to extende ofdm to ofdma how do i divide the sub carriers to say two users thanks Reply Krishna Pillai April 11. from a quick look it seems that there are issues in subcarrier assignment. 2009 at 1:59 pm hi all. I consider two hop communication and rayleigh fading channel with decode and forward relaying. Reply S.12/9/13 BER for BPSK in Rayleigh channel hfreq=fft(h. 2009 at 6:58 am @hayle: Simplistically. And between these two approaches.N).dsplog. op=reshape(op_vect. 2009 at 3:03 am Hello Sir. o=fde>0. hdiag=diag(hfreqinv).interleaved : where all even subcarriers are assigned to one user and odd subcarriers to another user . The information you have posted about matched filter are very intersting for me Reply hayle April 8. but i don’t know how to add the channel effect to my OFDM modulated signal thanks for anyone gives me a hand… Reply Krishna Pillai May 12.block : where -ve subcarriers are asisgned to one user and +ve subcarriers to another user. o_fft=(1/sqrt(nsubc))*fft(cprem).dsplog.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/ Hope this helps.i’ve already found a model that gives a matrix of the channel coefficients.nsubc). I am also worikng on multi-hop relay network. my email is assad. thanks Reply mrKim November 13. 2009 at 9:01 pm hi kirshina for both bpsk and ofdm using bpsk on multipath your BER curve is alomst the same.12/9/13 BER for BPSK in Rayleigh channel Krishna Pillai April 11.Alam. 2012 at 8:42 am Dear S.and ofdm is said to superior in multipath can you explaine this to me thanks Reply www.Alam Did you find material for this problem ? I am also worikng on multi-hop relay network. if you can give meur email address please. Reply mohammed April 5.abbasi@yahoo. 2009 at 4:50 pm Dear S.if we were to say OFDM is better we expect to get a va thanks Reply Krishna Pillai April 11.dsplog. 2009 at 6:16 am @Alam: Sorry. 2009 at 6:13 am @mohammed: As I said in my previous comment – in both the cases the signal experiences flat fading.plz contzct me on my email. I am new in this area and need some help from you. if you can give meur email address please. 2009 at 2:14 pm your simulation on the top was for BPSK in multipath and has 35dB at 10-4 which is the same value also for OFDM for multipath. 2009 at 2:09 pm thanks kirshina modifying BPSK do you mean using channels other than flat fadding for bpsk (give me an example)and OFDM i think is assumed flat fading . Reply Assad Abbasi May 22.com i’ll wait for ur reply. 2009 at 6:12 am @mohammed : Yes. my email nguyenkimhieuha@gmail. Reply mohammed April 5. thanks once againe Reply Krishna Pillai April 11.com i’ll wait for ur reply. Reply mohammed April 2. Hence the BER performance is comparable. I am new in this area and need some help from you.com/2008/08/10/ber-bpsk-rayleigh-channel/ 23/50 . I have not worked on co-operative communications. channels other than flat fading for BPSK.plz contzct me on my email. I want to ask you if there is a matlab code about using matched filter as an optimum binary detection. Ahmed Reply Krishna Pillai April 4. In most of the simulation models. 2009 at 10:08 pm Hi.dsplog. N). Hence both the simulations However. N)). % For Fast Fading. h_20 = sqrt(1 / 2) * abs(randn + j * randn) * ones(1. Channel coefficients changes from one symbol to the other ) thanks a lot in advance. coherance time symbol period . if you modified the BPSK simulation to have a multipath channel. However. How can this simulated?Also equiv integrator? Thank you very much. thanks to cylcic prefix is also having a flat fading channel. I have assumed flat fading channels and did not use filtering. But my question is: As we all know small scale fading (based on Doppler spread) is divided in to 1. 2009 at 7:41 am @Ahmed: Thanks.12/9/13 BER for BPSK in Rayleigh channel Krishna Pillai April 4.. channel variations are ofcourse faster than signal variations. thanks a lot in advance Reply Krishna Pillai April 4.Ramya March 27. Thank you for all these efforts.com/2008/08/10/ber-bpsk-rayleigh-channel/ 24/50 . Reply R. N). Channel coefficients are the same over block transmission. N). h_20 = sqrt(1 / 2) * abs(randn(1. what should i do for fast fading? (For Fast Fading. h_10 = sqrt(1 / 2) * abs(randn + j * randn) * ones(1. there are two post on transmit pulse shaping filters: www. Reply R. N)). 2009 at 8:32 am @R. 2009 at 10:53 pm i got the answer: for which i have posted previously: % For Slow Fading. % For Slow Fading. 2009 at 1:45 pm Greetings Krishna.Ramya: I have not tried simulating doppler. hence unable to help. Reply Ahmed March 25. Channel coefficients are the same over block transmission. I want to change it from slow fading to a fast fading. 2009 at 4:53 pm @mohammed: The BPSK simulation was using flat fading channel and the OFDM simulations. Sorry. N) + j * randn(1. Channel coefficients changes from one symbol to the other h_10 = sqrt(1 / 2) * abs(randn(1. h_10 = sqrt(1 / 2) * abs(randn + j * randn) * ones(1. the performance will be much poorer than with OFDM. N) + j * randn(1. there is high doppler spread .fast fading for fast fading.Ramya March 27.Slow Fading 2. h_20 = sqrt(1 / 2) * abs(randn + j * randn) * ones(1. N). channel variations are slower than signal variations How can one write code for simulating doppler spread ???? Can U help me by giving hint. gt1/10).com/2008/08/10/ber-bpsk-rayleigh-channel/ 25/50 . end end end figure semilogy(Eb_N0_dB. % example matlab code snippet to show matched filtering with a rectangular tx pulse shaping filter clear all N=7 am = 2*(rand(1.dsplog. % sampling frequency in Hz % recatangular filter gt1 = ones(1. 2009 at 12:09 pm hi all i have 3 for-loops here for kk=users for jj=receiver for ii=Eb_N0_dB nErr(jj.ipHat]). However. y-axis is bit_error.N)>0.2). …….’.N)>0.: .5)-1 + j*(2*(rand(1. 2009 at 3:51 pm www.’mo-’. amUpSampled = [am. x-axis is dB if i want to show what the error rate for each useris. You may simulate the integrator as a convolution function.. Some equalization structures for a 2×2 MIMO with V-Blast are discussed in http://www.gt1). where dimensions. % matched filter yt = conv(rt.code…….ii) = size(find([ip.simBer(1.'LineWidth’.fs). 2009 at 10:01 pm hello every body. the multiuser detection problem can in general be viewed as a MIMO V-BLAST transmission scenario. Reply rim March 23.dsplog. % received seqeunce rt = conv(amU. % extracting the samples at = yt(10:10:end-10) err = at-am Hope this helps.com/2008/04/22/raised-cosine-filter-for-transmit-pulse-shaping/ You may modify one of these to adapt to BER computation using matched filtering at receiver.12/9/13 BER for BPSK in Rayleigh channel http://www.dsplog. I am doing search on multiuser detection and I need some help to simulate CDMA system over multipath rayleigh fading channel.5)-1).com/tag/mimo Hope this helps. Reply Martin March 19.length(am))].dsplog..com/2008/04/14/transmit-pulse-shape-nyquist-sinc-rectangular/ http://www. Reply Krishna Pillai March 25.2). amU = amUpSampled(:). What should i put in nErr(??.??)???? Reply Krishna Pillai March 21. 2009 at 5:47 am @rim: We have not yet written posts on CDMA systems.zeros(fs-1. % generating random binary sequence fs = 10. 12/9/13 BER for BPSK in Rayleigh channel @Martin: Maybe you should make a three dimensional matrix. chan_type) BER_sic=zeros(size(SNR_dB)). Nb. SNRchip=SNR/N. I have not tried simulatiing MIMO with adaptive equalizers.’) error_count=0. 2009 at 3:49 pm @pradip: Sorry. %spreading factor G(:. P.… 1. b=1 or 0 b=input_symbols(K.can you help me. I confused. help me if you have any matlab based simulation plz.jj.ii) = size(find([ip. %number of user N=size(code_matrix. 2=rayleigh fading channel) % % output: % BER_sic=bit error of the sic receiver % function BER_sic=sim_sic_fn(SNR_dB.dsplog. %generate a bernoulli symbol.com/2008/08/10/ber-bpsk-rayleigh-channel/ 26/50 .2:K)=code_matrix(1:K-1. Both Matlab and Octave supports multi dimensional matrices. send me guidelines.. P.1).2).ipHat]). 2009 at 10:53 pm Hello sir. Reply pradip panchal March 18. for p=1:length(SNR_dB). I am Student of Research area. Were you looking for a channel tracking scheme? Reply wap March 11. Sir.. nErr(kk. G(:. Nb.what impact BPSK in high frequency? 2. thanks -pradip Reply Krishna Pillai March 21.can you fix the error? this the program % BER_sic=sim_sic_fn(SNR_dB. %generate the crosscorrelation matrix R R=G’*G. 2009 at 2:43 pm hi krishna we meet again ……. if chan_type==1 www. i. working on MIMO Adaptive equalizer. chan_type) % return bit error rate of the sic receiver in AWGN or rayleigh fading % % PARAMETER: % SNR_dB=signal-ti-nopise ratio in dB % P=power control vector. SNR=10^(SNR_dB(p)/10). I have problems. How to start in this area? pls. P(i)=transmitted power of i-th user % Nb=number of transmitted bit % code_matrix=matrix of the spreading code used % chan_type=channel type(1=AWGN. %loop for Nb symbol bits for n=1:Nb.e.1)=code_matrix(33.in this script program have one error. K=length(P). disp(‘processing. code_matrix.:)’. code_matrix.2).:)’. end %transmitted sinal X=G*(A. increment the error_count %if b_hat(user_index)~=b(1) error_count=error_count+1.. end end %carculating Bit Error rate i. the percentage of erroneous %symbol estimates BER_sic(p)=error_count/Nb. Reply Krishna Pillai March 21. 2009 at 7:46 am @ w@p: Sorry. end b_hat(1)=sign(y_sorted(1)-interference_estimate(1)). user_index=find(sort_order==1). Sorry. end thank before…. thanks… Reply Krishna Pillai April 4. in general. www.sort_order). b_hat(u)=sign(y_sorted(u)-sum(A_sorted(u+1:K). Hope this helps.1).K). 2009 at 7:07 am @wap: My replies: 1. 2009 at 5:57 pm thank khrishna for your answer……………. dbquit. elseif chan_type==2 A=rayleigh(1. Hmm… I dont think there is impact. %short users according tho their received powers [y_sorted.. A_sorted=A(sort_order). If you have explicit q’s I can try to answer them. were you refering to carrier frequency. By high frequency. %generate the observed data r=awgn_chan(x.*R_sorted(u+1:K.^2). Thanks.u). for u=K-1:-1:1.*sqrt(P’). b_hat(K)=sign(y_sorted(K)). %assume that the codes are known and that they are %perfectly synchronized %matched filter output y=G’*r. how in the code_matrix so that the program is replaced with the gold code? gold code so that this function can be called by sic….12/9/13 BER for BPSK in Rayleigh channel A=sqrt(P’). I refuse to debug the code.com/2008/08/10/ber-bpsk-rayleigh-channel/ 27/50 . %detect users successively b_hat=zeros(K.sort_order]=sort(y. %if detected symbol is incerrect. else disp(‘invalid channel type’).*b_hat(u+1:K))).SNRchip).e. am not familiar with the code which you provided. Reply w@p March 25.dsplog. y_sorted=y(sort_order). 2. R_sorted=R(sort_order.*b). 0dB variance h = 1/sqrt(2)*[randn(nRx(jj).N) + j*randn(nRx(jj). y1 = rand. 2009 at 11:38 am Hi~ Who can tell me how to establish communicate with basestation 1*m error rate. 2009 at 10:49 am i try to produce it am i right?? —————————–% Script for computing the BER for BPSK modulation in a % Rayleigh fading channel clear N = 10^6 % number of bits or symbols % Transmitter ip = rand(1. x2 = rand. because i need to produce distributed antenna system also. i have not enough time to produce Reply Martin March 12. sD = kron(ones(nRx(jj). % Rayleigh channel % Channel and noise Noise addition d = sqrt((x1-x2).com/2008/08/10/ber-bpsk-rayleigh-channel/ 28/50 . % BPSK modulation 0 -> -1. Please state your requirement in bit more details to enable a reader to help. Please.12/9/13 BER for BPSK in Rayleigh channel Reply Martin March 3.^2).N)>0. y = d^-2*h.dsplog. % multiple Eb/N0 values.1 with equal probability s = 2*ip-1. m is receivers and then run it 10^6 times.N)]. find out the error rate also in this simulation.s). I am doing my final year project. ratio of transmission power per bit to noise density x1 = rand. www.N) + j*randn(nRx(jj). 2009 at 9:06 am i need to produce a program like this requirement we have m receivers and n users randonly pick one user and communicate with Basestation we need to cal. please help me. Reply Martin March 10. y2 = rand. Eb_N0_dB = [-3:35].5. % generating 0.the 1*m error rate 1 mean 1 transmitter. i have 1 months only. 1 -> 0 nRx = [1 2].N)]. 2009 at 5:18 am @Martin: You question is vague. % white gaussian noise. for jj = 1:length(nRx) for ii = 1:length(Eb_N0_dB) n = 1/sqrt(2)*[randn(nRx(jj). it means 1 transmitter and m receivers it is randomly pick one user Please help. we need to use MRC it is a cellular system only. i still have many tasks havent done yet Reply Krishna Pillai March 5.1).*sD + 10^(-Eb_N0_dB(ii)/20)*n.^2 + (y1-y2). dsplog.theoryBer_nRx2. Reply Kenny March 1.^(-0. ylabel(‘Bit Error Rate’).2). dB’).’bp-’. Reply www.:).5. hold on semilogy(Eb_N0_dB. ‘nRx=2 (theory)’. its increasingly hard for me to debug the code.ipHat]). % plot close all figure semilogy(Eb_N0_dB. ‘nRx=2 (sim)’). % counting the errors nErr(jj.'LineWidth’.’ks-’. I am doing my final year project.2). ‘nRx=1 (sim)’. semilogy(Eb_N0_dB. Good luck in your algorithm explorations. theoryBer_nRx2 = p.^(-1/2). Reply Martin March 2.'LineWidth’. % receiver – hard decision decoding ipHat = real(yHat)>0.*(1-1*(1+1.1). % simulated ber EbN0Lin = 10.ii) = size(find([ip.*conj(h). 2009 at 12:13 pm Do you still need the solution to simplify the Pb in Rayleigh Fading? I have the answer./EbN0Lin).5]) grid on legend(‘nRx=1 (theory)’.*y. m is receiver it is randomly pick one user Please help.:). title(‘BER for BPSK modulation with Maximal Ratio Combining in Rayleigh channel’).com/2008/08/10/ber-bpsk-rayleigh-channel/ 29/50 ./EbN0Lin). due to time constraints. 2009 at 8:47 am Hi~ Who can tell me how to establish communicate with basestation 1*m error rate.simBer(2. 2009 at 7:00 am @Martin: Sorry. Krishna Pillai March 21.theoryBer_nRx1. semilogy(Eb_N0_dB. 2009 at 7:12 am @Martin: Sorry.2).^2. i have 1 months only. i still have many tasks havent done yet Reply Krishna Pillai March 5.2).simBer(1.2).*(1+2*(1-p)).'LineWidth’. I am not familiar with the system model which you proposing. —————————– Reply Krishna Pillai March 21.12/9/13 BER for BPSK in Rayleigh channel % equalization maximal ratio combining yHat = sum(conj(h). end end simBer = nErr/N.^(Eb_N0_dB/10).’rd-’.5)). Typically. 2009 at 4:56 am @Martin: You question is vague. one would want to have the error rate as low as possible. xlabel(‘Eb/No.’mo-’.1).'LineWidth’./sum(h. p = 1/2 – 1/2*(1+1. axis([0 35 10^-5 0. theoryBer_nRx1 = 0. www. y2 = rand(1. 2009 at 9:19 pm My program is fixed and reference to your program.1 with equal probability s = 2*ip-1.1.^(Eb_N0_dB/10).100]). y1 = rand(1. % white gaussian noise.N) + j*randn(1.M). % counting the errors nErr(ii. % BPSK modulation 0 -> -1.^2).M).12/9/13 BER for BPSK in Rayleigh channel Krishna Pillai March 5. 0dB variance h = 1/sqrt(2)*[randn(1.100]).N)].^-2.'LineWidth’.N) + j*randn(1.simBer.^2 + (y1(i)-y2(u)).’mx-’. d totalpwr = totalpwr+d^4./(EbN0Lin+1))).*h. x2 = rand(1. % Rayleigh channel % randomly pick two nodes and calculate the distance between them i = randint(1. Now I would like to assume each node has a total pt= 100 so that for each pick up.'LineWidth’.com/2009/01/22/derivation-ber-rayleigh-channel/ Reply VINCENT February 25. x1 = rand(1.5. % plot close all figure semilogy(Eb_N0_dB.I am trying to set a topology of M nodes which is 250.[1.dsplog. d = sqrt((x1(i)-x2(u)). y = d. for ii = 1:length(Eb_N0_dB) % Channel and noise Noise addition n = 1/sqrt(2)*[randn(1.each node used some of its energy to transmit and then therefore each node is different with the saved in pt so that to plot a graph how many nodes alive against the time. However.2).^(Eb_N0_dB/10))).M). % multiple Eb/N0 values %Generate M nodes M=250.*(1-sqrt(EbN0Lin. Mr.M).1.1) = size(find([ip. % generating 0.com/2008/08/10/ber-bpsk-rayleigh-channel/ 30/50 .*s + 10^(-Eb_N0_dB(ii)/20)*n.^2.my program is below: thank for you help % Script for computing the BER for BPSK modulation in a Rayleigh fading channel clear N = 10^6 % number of bits or symbols % Transmitter ip = rand(1./h.5*erfc(sqrt(10.and then randomly pick 2 nodes and repeat 1000 times for each time.5.ipHat]).dsplog.2). % theoretical ber EbN0Lin = 10. 2009 at 4:27 am @Kenny: Thanks.theoryBer.N)>0. u = randint(1. whole_error totalpwr simBer = nErr/N. hold on semilogy(Eb_N0_dB. % receiver – hard decision decoding ipHat = real(yHat)>0.N)].pick two the channel between them and calculate error performance.2).The error performance of the whole network is calculated and sum up all the d gives the total transmission power.[1. Jose Antonio Urigüen kindly shared his findings. The URL: http://www.’bp-’. % equalization yHat = y.*d. theoryBer = 0. % simulated ber theoryBerAWGN = 0. end % error performance of the whole network whole_error = sum(nErr)/N. 1 -> 0 Eb_N0_dB = [-3:96]. % initalize the total power totalpwr = 0. xlabel(‘Eb/No. Thank you for your explanation. Reply Street hawk August 27. I wanted to say – I was not familiar with the scenario which you presented (and hence unable to help). Reply VINCENT February 28. Fast fading is w Filbert February 23. 2009 at 5:14 am @Street hawk: Its flat fading. Reply Krishna Pillai March 1. no doppler spread. However.your help is much considerable as i really frustrated about this qu Reply Krishna Pillai February 28. 2009 at 7:04 pm The fading considered in your program is Flat and Slow rayleigh fading where there is no doppler spread i. Let me try to do some reading and get back to you. ‘Rayleigh-Simulation’). Reply VINCENT February 27. I just realized a typo in my message.5]) grid on legend(‘Rayleigh-Theory’.however i received your bad news about your reply. I am not familiar with the scenario which you are proposing (and hence unable to help). 2009 at 10:15 pm Hi Kirshna . could you give me some hints on how to solve the problem or give guideance on how to solve.but i really don’t understand what is the relationship between your familiarity and m fix my program. title(‘BER for BPSK modulation in Rayleigh channel’). 2009 at 10:05 am Krishna. 2009 at 7:57 am @Vincent: Sorry.dsplog. Ts -symbol duration). where To.com/2008/08/10/ber-bpsk-rayleigh-channel/ 31/50 . I am glad to receive your reply. Filbert February 24. dB’). 2009 at 9:50 am www. ylabel(‘Bit Error Rate’). the channel varies randomly from each symbol. Am I right? Reply Krishna Sankar September 7.12/9/13 BER for BPSK in Rayleigh channel axis([-3 96 10^-5 0. What do you think? Thank you Reply Krishna Pillai February 26.thank you very much. Reply giro82 December 21. 2009 at 6:58 am @vincent. But i think we should consider the Doppler shift in Rayleigh channel.channel coherence time.e. So its fast fading. max doppler shift (fm=v/lamda) is zero. 2009 at 8:27 am Khrisna. 2009 at 4:10 am I think that if channel is changing every symbol it is mean that it is slow fading (To>Ts. 2009 at 5:59 am @Filbert: I have not tried modeling Doppler.or may you give some any others useful link or reference so that i know more details about what happened?your reply is appreciate. 2009 at 2:32 pm hi……. 2009 at 1:45 pm Hi Krishna. I tried to simulate BER for OFDM transmission via Rayleigh channel. Thanks. not just random complex number? Thank you Reply Krishna Pillai February 24.dsplog. when you use ‘randn’.N)] I notice that the formula for h and n (AWGN) is the same. So to make the variance of the total variance to unity. -Jamil Reply Krishna Sankar November 14. 2010 at 12:19 am Hi Krishna. in Matlab. one for real and another one for imaginary. Reply Krishna Pillai February 21. the random gain and phase error introduced by the channel results in high BER. Good day.can u plz tell me how can i find the ber of a qpsk in rayleigh fading channel.com/2008/08/10/ber-bpsk-rayleigh-channel/ 32/50 .N)+j*randn(1. note that h is multiplied on the transmit signal. So the effects of h and n are different. 2010 at 10:37 am @Jamil: Recall.12/9/13 BER for BPSK in Rayleigh channel Khrisna.com/2008/07/14/rayleigh-multipath-channel/ for bit more details. 2009 at 5:34 am @Filbert: Well. we create two random variables. I wonder if in OFDM receiver i need equalization? I did not use equalization and i Reply Krishna Pillai February 22.dsplog. You told that sqrt(1/2) is used to make the variance unity. we need equalization. by default. How are you? I hope you are fine. whereas n is added to the transmit signal. Reply www.. Is it suppose to have its own model. it creates gaussian random variables with zero m with sqrt(1/2)? Looking forward to your reply. Without equalization. the factor of 1/sqrt( Reply Filbert February 22. For Rayleigh channel you write: h = 1/sqrt(2)*[randn(1. Thank you for your response. the Rayleigh channel can be modeled as independent Gaussian random variables on the real and imaginary compnents. However. The factor 1/sqrt(2) to normalize the power o http://www. 2009 at 7:37 am @ranjay: Did you want to try modify the Matlab code for BPSK and extend to QPSK case. Further. 2009 at 2:31 pm @Filbert: Yes. There is a problem about your Matlab’s script i do not understand. Hope this helps Reply Jamil November 6. Reply ranjay February 19. Why? I think you just generate random complex number for Rayleigh channel. 2012 at 6:27 am @Leona: You can look at the post on Selection Diversity for BPSK case http://www. Khalid A. Senior Member. This scheme employs a new version of generalized selection combining (GSC). RAKE receiver. Can you replace SNR with SINR to compute BER ?. Please see this code . and the SHO overhead.com/2008/09/06/receiver-diversity-selection-diversity/ Reply Abrar January 22. 2009 at 10:45 am Hi Kirshna Thanks for ur reply. Hence. 2009 at 10:06 am Hi Krishna.Initially I have done IFFT of the signal with Four subcarriers. Index Terms—Fading channels. the receiver uses more resolvable paths from the target BS to improve the performance. p1=1. in the SHO region.12/9/13 BER for BPSK in Rayleigh channel Arvind February 16.Ple x=transdata1. relying on some recent results on order statistics we attack the statistics of two correlated GSC stages and provide the approximate but accurate closed-form expressions for the statistics of the output SNR. Mohamed-Slim Alouini. IEEE. 2. Suppose the interference is another BPSK modulated signal. 2009 at 10:50 pm IEEE TRANSACTIONS ON COMMUNICATIONS. By investigating the tradeoff among the error performance. More specifically. Your thoughts. 2012 at 6:23 pm Hi I am looking for generalized selection combining for QPSK (or for anything else). VOL. and Hong-Chuan Yang. I would think that the BER performance will be poorer in that case. Senior Member. Reply vasundhara January 29. NO. the receiver uses by default only the strongest paths from the serving base station (BS) and only when the combined signal-to-noise ratio (SNR) falls below a certain pre-determined threshold. Member. the signal can be corrupted by another BPSK modulated signal. Arvind Reply Krishna Pillai February 21. IEEE Abstract—We propose and analyze in this paper a new finger assignment technique that is applicable for RAKE receivers when they operate in the soft handover (SHO) region. FEBRUARY 2008 213 Soft Handover Overhead Reduction by RAKE Reception with Finger Reassignment Seyeong Choi. performance analysis. taps=2. the path estimation load.com/2008/08/10/ber-bpsk-rayleigh-channel/ 33/50 . www. we show through numerical examples that the new scheme offers commensurate performance in comparison with more complicated GSC-based diversity systems while requiring a smaller estimation load and SHO overhead. IEEE. generalized selection combining (GSC). 2009 at 7:08 am @Arvind: Yes. Any help please where can I find it? Reply Krishna Sankar January 26. How do you consider the effect of interference in this simulation ?.dsplog. diversity techniques.dsplog. IEEE. Senior Member. I am confused how i added the two version of signal received from two Taps with one sample delay. Reply Leona January 25. However. Qaraqe. 56. 12/9/13 BER for BPSK in Rayleigh channel p2=0.length(x)) + j*randn(1.ucla. www. x=transdata1.*(1. % Noise snr = [0:10]. gain1=sqrt(p1/2)*[randn(1. Reply Abrar January 11.^2).com/2008/08/10/ber-bpsk-rayleigh-channel/ 34/50 .length(x)) + j*randn(1. for n=delay1+1:length(x) % Delay of one sample in second tap x1(n)=x(n-delay1). 2009 at 7:48 am Hi Kirshna i have three taps and showing below the channel description. delay1=1. if u could do it for me i would be very thankful to you.length(x)). % multiple Eb/N0 values ps=mean(abs(x).ee. it is very urgent for me. channel_ifft=ifft([gain1. gain2=sqrt(p2/2)*[randn(1. n=1:length(x). can u guide me how I equlize the channel now.length(x))]. thanks dean Reply Krishna Pillai January 13. 2009 at 8:53 am @Fang: Thanks for the link Reply dean January 11.gain2]. % Power of the transmitted signal for i = 1:length(snr) y = transdata + (sqrt(3*ps)*10^(-snr(i)/20))*noise./(channel_ifft)).html It’s very accurate for fast fading channels! Reply Krishna Pillai January 17.edu/~chkomn/RayleighFiles/files. %Equilizatiom Take care. I typically help people in their simulation model development rather than code myself.dsplog. %Addition of Noise %————————–Receiver ————————————— recdata=y.length(x)) + j*randn(1. % confusing here %————————Addition of noise ——————————noise = 1/sqrt(2)*[randn(1.*(x+x1).8. You may look at the post on convolutional coding.length(x))]. I produced the delay of one and two samples in 2nd and third taps. rx0=recdata. Reply Fang January 16. 2009 at 8:50 am Hi! For those who are looking for a more accurate model of the fading coefficients can read the paper by Christos Komninakis and download the program he wrote at: http://www.length(x))]. 2009 at 5:45 am @dean: Am sorry. 2009 at 8:36 am please help me to solve the following writing the matlab code about RCPC code family with memory M = 4 and puncturing period P = 8 and choose overall code rate R = 1/4 with source block size K = 128 bits. end transdata=channel_ifft. Viterbi decoding Good luck. h).length(x)) + j*randn(1. % writing the channel using toeplitz matrix op2 = x*hM . 1. 2009 at 11:03 am Thanks Kirshna. This is described in detail in Chapter 3.com/2008/08/10/ber-bpsk-rayleigh-channel/ 35/50 . 2. 2. end for n=delay2+1:length(x) x2(n)=x(n-delay2). Why is each path gain1.length(x)-1) ]). Take care.length(x))]. gain2. n=1:length(x). delay1=1.length(x)-1) ]. %————————Addition of noise ——————————noise = 1/sqrt(2)*[randn(1. % multiple Eb/N0 values ps=mean(abs(x).length(x))].^2). clear all. Reply www.length(x)) + j*randn(1.Can I go for normalize the channel. In the code snippet.dsplog.5. gain2=sqrt(p2/2)*[randn(1.length(x)) + j*randn(1. This confirms that toeplitz way of representing h is correct. xHat = op2*pinv(hM) % dividing received symbol with pseudo inverse of the channel to perform equalization The code performs the simple zero forcing equalization. % channel op1 = conv(x.8. Reply Krishna Pillai January 13. I find the code snippet which you have provided bit confusing. % Thanks.*x+gain2. I would have thought that each path is a single element.5)-1 % input sequence h = [ 1 2 3]. Instead of using the for loop’s you could have used a convolutional operator. Reply Krishna Pillai January 16. the convolution operation is represented as product a vector and a matrix. gain3 having length of the input vector. end transdata=gain1.if i made power of tap 2 and 3 zero it becomes flat fadding and zeroforcing i equilize the channel. gain3=sqrt(p3/2)*[randn(1. % verifying that both the outputs are the same. p1=1.3 of Digital Communications: Fundamentals and Applications by Bernard Sklar Hope this helps.12/9/13 BER for BPSK in Rayleigh channel taps=3.4. % output of channel hM = toeplitz([h(1) zeros(1. delay2=2. 2009 at 5:52 am @mabrarbari: If I may. To represent mathematically.can u give me any othe alternate to represent frequency selective channel. Reply Abrar January 13. your channel is not a flat fading channel. p3=0.close all x = 2*(rand(1. Yes I have created frequency selective fadded channel in which there is a one sample delay in taps. Need to formulate the multipath channel as matrix and solve the equation. At the estimate.7)>0.length(x)) + j*randn(1. 2009 at 6:18 am @Abrar: May I try to provide you a simple Matlab code snippet for equalization in the case of a 3 tap channel. % Noise snr = [0:10]. gain1=sqrt(p1/2)*[randn(1. p2=0.length(x))]. Some questions: 1. % finding the output using the matrix multiplication way op1 – op2.length(x))]. [h zeros(1. for n=delay1+1:length(x) x1(n)=x(n-delay1).*x2. % Power of the transmitted signal for i = 1:length(snr) y = transdata + (sqrt(3*ps)*10^(-snr(i)/20))*noise.*x1+gain2. SNR can be computed. 2009 at 2:47 pm Thank u for ur reply. 2009 at 6:24 am @shoumi: Yes.length(x))]. Given that you know the transmit power. if channel become zero then wht happen if we used equlization by dividing.. p3=0. gain3=sqrt(p3/2)*[randn(1. Yes i calculate the received power for each node. end www.wikipedia.i have to know the noise at each each receiver AWGN noise???.org/wiki/Log-distance_path_loss_model Hope this helps. I can not understand how to start ……Please reply me…. frequency 2. Reply Krishna Pillai January 10. path loss exponent.By considering the following parameters: BPSk modulation.length(x))].. Reply Abrar January 6. delay1=1. I have defined the channel as x=transdata1. As u made equilization by just dividing the received signal through channel.wikipedia. now come back and start working. for calculating the SNR these unit must be same…how can i conver the awgn noise into dBm..org/wiki/Thermal_noise Hope this helps.Please he Reply Krishna Pillai January 16. But the noise power can be represented in dBm. 2009 at 3:24 pm Dear sir At first i want to give you thank for this interesting blog…. gain1=sqrt(p1/2)*[randn(1. p2=0.dsplog. it seems like you are looking for finding the path loss from between A to B and A to C. For example. Awgn noise is a complex value. it should be reasonably easy to find the received signal power. for n=delay1+1:length(x) x1(n)=x(n-delay1).. The noise floor in dBm You may find bit more details on the equation @ http://en. The link in wiki on path loss might be helpful http://en. Once the received power is known. any other way to equilizing. 2009 at 8:37 am Hi Kirshna I am away some time from country . Reply shoumi January 15. transmitter power 15 dB. AWGN channel.. i have to calculate the recieved signal to noise ratio at node B an It would be nice if u help me by giving some code or any suggestion..length(x))]. As i am a new user of matlab i faced some problem during c using matlab: Calculate path loss between 3 wireless node.com/2008/08/10/ber-bpsk-rayleigh-channel/ 36/50 .12/9/13 BER for BPSK in Rayleigh channel shoumi January 8. p1=1.and the recived signal is in dBm unit. 2009 at 9:24 am @Shoumi: From your problem statement. b noise bandwidth).i am waiting for your reply…… with regards shoumi…. gain2=sqrt(p2/2)*[randn(1. and the distance.as the 3rd node C is located near to the node B it also recieve some signal . n=1:length(x). taps=3.4 Ghz.i go through ur posts of matlab code these are really helpfull for me.length(x)) + j*randn(1.length(x)) + j*randn(1.length(x)) + j*randn(1. delay2=2. patloss exponent transmitting and 2nd node B is receiving signal. Now for calculating the SNR for each receiving node . assume the receiver bandwidth is 20MHz. the noise is complex. Ramya December 20.total path gain of the channel is not close to 1. 2.1). end transdata=gain1. I think length(h) in estTapWt is Normalisation factor.1)) o/p: est_tap_weight_db = -8. taps_norm = 1/norm_fact*norm_each_tap_weight.^2.dsplog. 1.ofcourse. 10^4.Ramya December 28. Reply Krishna Pillai January 10.length(tapWtdB)) + j*randn(10^4. % Power of the transmitted signal for i = 1:length(snr) y = transdata + (sqrt(3*ps)*10^(-snr(i)/20))*noise.length(tapWtdB))). Thank you for giving me the hint. norm_each_tap_weight=taps_weights/sqrt(length(tap_weights_ln)).12/9/13 BER for BPSK in Rayleigh channel for n=delay2+1:length(x) x2(n)=x(n-delay2). the total path gain of the channel is not close to one.com/2008/08/10/ber-bpsk-rayleigh-channel/ 37/50 .TO NORMALIZE THE RECEIVED POWER.10^4)]. Reply R.^2)).^2)).1991 Here.5813 -18. z=mean(abs(taps_norm ).^2).6429 total_path_gain_of_channel = 0. its value is less because of normalisation) since.length(x))]. In the last post You wrote: Incase of flat fading. 2009 at 9:06 am @Abrar: If the channel becomes close to zero.TO NORMALIZE EACH TAP WEIGHT: I divided taps_weights by sqrt(length(tap_Weight_ln)).^2). taps=1/sqrt(2)*(randn(10^4. 2008 at 3:51 pm Thank you for your response sir. % Noise snr = [0:10]. equalization by dividing by the channel results in noise amplification.10^4) + j*randn(1. taps_weights = taps. %————————Addition of noise ——————————noise = 1/sqrt(2)*[randn(1. % Calculation of normalization factor to %make the average power of output signal to 1 norm_fact = sqrt(sum(tap_weights_ln. % At receiver how I equlize it.^(tapWtdB/20).*x1+gain2. 2008 at 10:15 pm Sir.6063 -23.*repmat(tap_weights_ln.*x2.(very less comparatively) (but the estimated tap weight is close to the original tapweight(dB) . As you said. est_tap_weight_db=10*log10(z) total_path_gain_of_channel=sum(mean(abs(taps_norm). Is it acceptable one Sir? Waiting for your reply. Matlab/octave code snippet to illustrate: tapWtdB = -15 h = 10^(tapWtdB/20)*1/sqrt(2)*[randn(1.6703 -13.*x+gain2. estTapWt = 10*log10(h*h’/length(h)) estTapWt is obtained very close to -15dB. norm_fact = sqrt(sum(tap_weights_ln. Reply R. tap_weights_ln = 10.length(x)) + j*randn(1. www. % multiple Eb/N0 values ps=mean(abs(x). tapWtdB = [ -5 -10 -15 -20 -25].6805 -28. e.4893 -22.0dB variance h= 1/sqrt(2)*[randn(1. question 3: whether the tap (in flat fading)will occur at 0 microseconds 0r 0 ns i. Firstly.N) + j*randn(1.estTapWt=10*log10(z). My question is Whether the first tap necessarily be 0dB or someother dB value.^(tapWtdB/20).% Rayleigh channel From theory.1). These delays are relative to the delay of the tap to which demodulator synchronizes.V. from the Power delay profile. z=mean(abs(taps_weights/sum(tapWtdB_linear)).12/9/13 BER for BPSK in Rayleigh channel In case of Multiple taps tapWtdB = [0 -20 -21].estTapWt estTapWt = -1. Tap_weight_db here in our case is = 0 dB.^2).^2).5174 PowerdB level is someWhat close to the original tapWtdB.Vs. without delay. h is 1.N)]. if the tapWtdb is [-15 -20 -21]. Secondly.N)].Ramya December 18. tapWtdB = [-15 -20 -21].3169 -11. In linear scale its value is 1. taps_weights = h. one would want to normalize each tap such that the relative power is as per the tap weight. tapWtdB_linear=10. Since the variance of rayleigh R.length(tapWtdB)) + j*randn(10^4.3482 -12.estTapWt=10*log10(z). h=sqrt(X^2+Y^2)=abs(X+jY). tapWtdB_linear=10.the received signal r is written as r=(Tap_weight * s) + n. But. I understood & got the answer for the last two questions Which i have posted previously. z=mean(abs(taps_weights/sum(tapWtdB_linear)). This happens becuase of the Normalisation (1/sqrt(2)) in h line in tha Matlab code.2874 Here the difference between the consecutive taps power level (db) is satisfied.*repmat(tapWtdB_linear. taps_weights = h. But my first question was In BER_simulation_BPSK_Rayleigh_channel Matlab Code: given two lines seems to be same n = 1/sqrt(2)*[randn(1. Please Check Whether the answers are right. www. we have the Tap weights in dB. h = 1/sqrt(2)*[randn(10^4. Hope this helps. one may want to make the average power from many such channel realizations to unity.If we can have some other value of power dB for the first tap then Can U please correct the Matlab code inorder to get or Reply Krishna Pillai December 25. Tap_weight = h*(10^(Tap_weight_db)/10 )=h*1=h As per theory.% WGN.1). estTapWt value is not closer to original original value. 2008 at 11:10 pm Sir.com/2008/08/10/ber-bpsk-rayleigh-channel/ 38/50 .or shall the tap occur after some particular delay? The tap doesn’t actually occur at 0 microseconds. there are two aspects: 1. 10^4.length(tapWtdB))]. 10^4. question :2 After modelling has absolute value of complex gaussian R. Why ‘abs’ have not been included ? Waiting for your reply.estTapWt estTapWt = -6.. to normalize the received power.*repmat(tapWtdB_linear.^(tapWtdB/20).N) + j*randn(1. Reply R.dsplog.length(tapWtdB))].length(tapWtdB)) + j*randn(10^4. h = 1/sqrt(2)*[randn(10^4.5181 -21. This can be accomplished by scaling each tap as in the example which I have s 2. 2008 at 7:23 am @Ramya: In the case of multiple taps. typical receivers will be having a packet detection circuit which can estimate the start of the symbol. CDMA System Engineering Handbook.V.sqrt(X^2+Y^2)=1/sqrt(2). 2008 at 7:40 am @Shefo666: I think the ZF equalizer is optimal in SISO systems.N) + j*randn(1. it is assumed that the phase distortion caused by the channel can be uniformly distributed between 0 to 2pi.Vs with zero mean and Variance of 1/2 each.V. waiting for your reply.N) + j*randn(1. of taps is one. Hence we model it as independent comple Please look at http://www. 0dB variance n = 1/sqrt(2)*[randn(1.abs(X+jY) if X & Y are two gaussian R.10^4)].e.N)]. A quick Matlab/octave code snippet to illustrate: tapWtdB = -15 h = 10^(tapWtdB/20)*1/sqrt(2)*[randn(1. convolution becomes multiplicati mutiplying with Guassian Noise with linear scale Eb_No) 3. I agree that since we are assuming flat fading. from the Power delay profile.. % white gaussian noise. sorry for troubling U sir. why ‘abs’ should be used? 2. I saw your Matlab code for BER_simulation_BPSK_Rayleigh_channel. the power delay profile has only one tap.N) + j*randn(1.This is my first sincere effort in learning digital comm conceps clearly. In the Matlab code. Rayleigh R.or shall that tap can occur after some particular Am i correct in this regard. if it is not correct kindly explain me. since flat fading has been used no.Both the above lines are same ( even though complex guassian R. 2008 at 6:15 am @Alex: Thanks.After modelling h.com/2008/07/14/rayleigh-multipath-channel/ for bit more details. of taps will be only one) Shall we convert tap weights in dB to linear scale and multiply with h and txmitted signal s (since inourcase only one tap is being considered for flat fading.N)]). thanks for sharing the understanding of this subject.12/9/13 BER for BPSK in Rayleigh channel Reply R.*abs([randn(1. 2. As Rayleigh channel is modelled as |h| |h|=1/sqrt(2).(In our case as theory suggest. since the no. With the Rayleigh channel. estTapWt = 10*log10(h*h’/length(h)) 3. 2008 at 7:23 am Sir. as i am struggling to get hold of things right.s were used) Whether the line given below is correct.N)]. while the Q(. h=1/sqrt(2).10^4) + j*randn(1. % Rayleigh channel h= 1/sqrt(2)*[randn(1. 2008 at 6:32 am @Ramya: 1. Regarding the missing part. one can find it on Page 823 in the book. It is all about some mathematic manipulations. Typically there will be small delay. Hence for modeling purpose we Reply Alex December 17. my question is whether that particular will occur at 0 microseconds 0r 0 ns i. Reply Krishna Pillai December 19. First. We should scale the variance of channel h in accordance with the gain of the power powe tapWeightdB/20) and not 10^(-tapWeightdB/10) .com/2008/08/10/ber-bpsk-rayleigh-channel/ 39/50 . Let me try to get my hands on the book. without delay. For flat fading. www. 2008 at 8:14 pm hi there.dsplog.) function is used to replace the erfc function in the expression.dsplog. My question are: 1.Ramya December 18. Reply Krishna Pillai December 18. we get the Tap weights in dB . Reply Krishna Pillai November 22. However. etc for SISO It shows MMSE is better than ZF for SISO.1 with equal probability s = 2*ip-1. 2009 at 3:44 pm Page 141 Reply Krishna Sankar September 9. am not sure whether we can call it as ZF/MMSE equalization – as there i % Matlab/Octave code snippet for comparing zero forcing and MMSE equalization for SISI clear N = 10^4 % number of bits or symbols ip = rand(1.*s + 10^(-Eb_N0_dB/20)*n.google.com/2008/08/10/ber-bpsk-rayleigh-channel/ 40/50 .2) Can see that nErr_zf and nErr_mmse is the same. % BPSK modulation 0 -> -1.ipHat_mmse]). n = 1/sqrt(2)*[randn(1. % counting the errors nErr_zf = size(find([ip.N) + j*randn(1. Digital communications) affected ? can u reccommend any papers that equalization over flat fading . Eb_N0_dB = 3.. % generating 0. Hope this helps.*conj(h). Let me try to get the book from the library. One query: Is the claim that “ZF is better than MMSE for SISO” for a flat fading channel? Reply Shefo666 November 21.N)].N)>0.dsplog.*conj(h)+ 10^(-Eb_N0_dB/10)).12/9/13 BER for BPSK in Rayleigh channel With a simple Matlab/Octave script may I try to show that ZF and MMSE equalizer gives the same BER. % mmse equalization % receiver – hard decision decoding ipHat_zf = real(yHat_zf)>0. MMSE. Most papers i got assume ZF equalization when it comes to SISO systems ! Reply Krishna Pillai November 15. ipHat_mmse = real(yHat_mmse)>0./h.*y. Regards Reply WirelessNewbie September 3.ipHat_zf]). Reply WirelessNewbie September 3. Thanks for the very interesting blog . 2009 at 3:43 pm Hi Krishna could you please refer : http://books.. 2008 at 8:27 am www.2) nErr_mmse = size(find([ip./(h. Infact.N)]. % zf equalization yHat_mmse = 1. % Rayleigh channel % Channel and noise Noise addition y = h. and I will respond. 2008 at 5:18 am Dear Krishna Pillai.N) + j*randn(1. the page 141 is not available from the link you provided. 0dB variance h = 1/sqrt(2)*[randn(1. I am wondering whether it makes any sense to apply MMSE and ML equalization on SISO communication systems in order to get over the ZF equalization major problem of noise enhan In such a case. 2009 at 5:32 am @WirelessNewbie: Sorry. % equalization yHat_zf = y.5.com/books?id=3DY6OAIGu0kC&printsec=frontcover&source=gbs_v2_summary_r&cad=0#v=onepage&q=&f=false (Introduction to Space Time Communications) Which gives a comparison of ZF. how is the theoretical BER performance of BPSK (for instance) over flat rayleigh (given by proakis. % white gaussian noise. the estimate of H is. Hope this helps. Typically for channel estimation. abrar Reply Krishna Pillai November 7. we can estimate the channel. First thing is that we will be sending information on both real and imgainary arms. i was very happy as it improve my knowledge and releive my burden. I was in need to compute the Bit error rate of BPSK and QPSK in AWGN and Rayleigh fading channel. Happy learning! Reply Krishna Pillai November 15. the system model can be written as Y = HX + N where Y – is the received symbol on subcarrier k H – is the channel on subcarrier k X – is the transmitted symbol on subcarrier k N – is the noise on subcarrier k Since X is known. Using the knowledge of the known sequence and what we received. I was travelling.com useful for your studies. So I need ur help in modeling frequency selective channel. Could you please tell me how the code to apply the fading channel would ch Reply Muhammad November 14. it will helpful for me. we send a known sequence (called preamble).Hoping U r fine.com/2008/08/10/ber-bpsk-rayleigh-channel/ 41/50 .com/2007/11/06/symbol-error-rate-for-4-qam/ as reference. Thanks for all Reply Abrar November 10. 2008 at 1:30 pm Hi Krishna. I am some extent. use the infor You can use the Matlab model provided here http://www.dsplog. Correspondingly. if u have any code about frequency selective chanel estimation. Glad that you are finding http://www. Thanks nad Take care. After finding this document. 2008 at 8:17 am @Muhammad: Thanks. I am trying to follow this tutorial and extend it further to simulations for 4-QAM over Rayleigh fading channels. 2008 at 12:45 am I am Muhammad from Pakistan. Sorry for the delayed response. 2008 at 6:43 am www.12/9/13 BER for BPSK in Rayleigh channel @Tahmid: Moving the simulation to 4-QAM should be reasonably simple. I am doing Postgraduate diploma in Massey University N I am doing simulation on MC-CDMA.dsplog. in a multi-carrier OFDM system. For eg.dsplog. 2008 at 3:42 am Hi Kirshna thanks for ur reply and sorry for the t I am saying thanks very late bec i am busy in my exam. H^ = Y/X Does this help? Reply Tahmid November 14. 2008 at 8:01 am @Abrar: Thanks for the comment. waiting for ur reply. may GOD bless u. Reply Krishna Pillai November 15. N)]. this is a simple form equalization. as the derivations are for unity channel gain. 2008 at 2:34 am Hello Kirshna I doing project on bfsk with rayleigh multipath chanel i wish to ask you if I use not an envelop but modulated fsk 0->cos(f1*t) and 1->cos(f2*t) how can I simulate rayleigh multipath chanel for bfsk in this case? thank you Davis Reply Abrar October 25. I think it is required. Reply davis October 27. 2008 at 9:51 am @Abrar: Sorry for the delayed response. I had written a post on BFSK some time in the past. for Rayleigh? Coz I think. Lee. 2008 at 7:32 pm Hi. bec. You can convolve the transmit signal x with the impulse response of the channel (lets say h) before adding the noise n. can u give some explation about equlization or refer some material about it.12/9/13 BER for BPSK in Rayleigh channel @Sky: 1/sqrt(2) is for normalizing the channel gain to unity. I got bogged down by viral fever.dsplog. Reply Sky Stradlin November 6.dsplog. www. Let me try to go over it by over the week. the equalization becomes just a division. Since this a simple one tap channel. Yes. David G. Messerschmitt. Could you please explain on how you get h = 1/sqrt(2)*[randn(1. Reply Krishna Pillai October 29. by John R. you can determine the double integral in this fashion to obtain the desired result. which basically tries to make the effective channel as impulse. 2008 at 8:36 am Hi Kirshna: hoping u r fine.N) + j*randn(1. 2008 at 12:08 pm Hi Krishna. Edward A.N) Thanks Reply Krishna Pillai November 5. 2008 at 5:34 am @Leon: Thanks. 2008 at 9:55 am @davis: Sorry for the delayed response. Hope this helps. The derivation has been pending for a while from my side. Reply Krishna Pillai October 29. I was down with viral fever. Jussi Poikonen is correct. I just want to ask about equlization which u have done here just by dividing by channel.N) + j*randn(1. is it another method of equlization. I want to understand it. Barry. Reply Leon Craven November 3.com/2007/08/30/bit-error-rate-for-frequency-shift-keying-with-coherent-demodulation/ The post describes BFSK in AWGN case. it should be just randn(1.com/2008/08/10/ber-bpsk-rayleigh-channel/ 42/50 . URI: http://www. This can can read more about equalization in Chapter 8 of Digital Communication: Third Edition. The integration problem is finally reduced to single integrals from 0 to infinity over zero-mean Gaussian distribut Reply Krishna Pillai October 7. ok sir thank u for ur fas Reply Krishna Pillai October 17. Let me try to go over the steps per your suggestion. 2008 at 10:05 pm Sir How to derive the probability error of Non-coherent Non-Orhogonal modulation. 2008 at 9:26 pm @Jussi Poikonen: Thanks for the guidance. and changing the order of integration. Reply www. Are there some practical systems taking advantage of non-orthogonality to improve spectral efficiency. Someth Can you give an example for non-orthogonal modulation? Reply Sairam October 16. Reply Krishna Pillai October 19. there are quite a few posts on Rayleigh channel URI: http://www. TRhanking you sir!! Reply Krishna Pillai October 16. Reply Jussi Poikonen October 15. Correct? I have not tried to discuss the deivation for BER with non-coherent modulation in any blog post yet. hope you meant a scheme like DBPSK. 2008 at 6:42 pm @Sairam: Ok. But the derivations become more complicated. Further.12/9/13 BER for BPSK in Rayleigh channel Tahnks and take care. thanks. 2008 at 5:01 am @nano686: This post does the simulation with a Rayleigh channel.dsplog. the advantage is that it provide high spectral efficiency. Can you please point me to the same. Reply Sairam October 18. 2008 at 5:01 am @Varun: Probability of error in Rayleigh fading channel.com/tag/rayleigh/ Hope this helps. and then with respect to x from 0 to infinity. 2008 at 12:42 am You will find that the missing steps in the derivation above can be completed by writing open the final (double) integral. That is. 2008 at 3:27 pm it can be obtained if the orthogonal condition is not satisfied. 2008 at 10:16 pm @sairam: By non-coherent. integrate first with res complementary error function). Reply Krishna Pillai October 7. abrar Reply Sairam October 20.dsplog. 2008 at 10:32 pm yES SIR IT IS USED IN OPTICAL COMMUNICATIONS.com/2008/08/10/ber-bpsk-rayleigh-channel/ 43/50 . www.. here the random variable is instantaneous SNR. if you can prove the equatio Thanks. Thanks and Regards.12/9/13 BER for BPSK in Rayleigh channel nano686 October 6. do you know how to complete the proof? I have not figured that out. I don’t know simulate Rayleigh channel by Matlab. So. we need to average over all channel probability. Kindly let me know. Reply V Varun October 4. Btw. 2008 at 4:15 pm Hi.com/2008/08/10/ber-bpsk-rayleigh-channel/ 44/50 .. 2008 at 9:47 am @khurshid: Sorry. 2008 at 8:16 pm Hi. Reply V Varun October 3. 2008 at 8:45 am @Krishna Pillai Thanks a lot for giving me a reply. 2008 at 8:14 pm @Varun: Because of Rayleigh fading. the instantaneous SNR for a particular channel realization is |h|^2*Eb/N0. 2008 at 6:58 pm thanks krishna actually i have to show the performance comparison of different strategies of cooperative communication…. it is quit similar to relaying…. i have sent some matlab codes on krishna at dsplog com it shows some error which i fail to removed. different combining techniques at receiver may also be considered but not compulsory…. 2008 at 10:14 am @Varun: Yes. Reply khurshid September 8. Does that help? Reply V Varun October 2.. to find the average bit error rate. So this is similar to finding the mean of a random variable right !!! Here the random variable is instantaneous SNR right !!! Comment on this statement S Reply Krishna Pillai October 2. please help me in removing these errors…… Reply Krishna Pillai September 8.dsplog. In order to find probability of error in a rayleigh fading channel we will average the conditional probability of error of the particular modulation scheme in AWGN channel over the rayleigh explanation. 2008 at 12:05 pm @ Pillai Which equation ? Is it the probability of error in a Rayleigh fading channel or the probability of error in a AWGN channel ? Let me know so that i can come up with a solution if i know Reply Krishna Pillai October 4. Can you help me? Thanks and Regards. V Varun. I can help with your coding but not do coding for you. 2008 at 1:18 pm @Lealem: Yes. the channel experienced by the individual subcarriers will still be flat fading channel. hope fully ur script is very very help full for my work but still i have doubt on how to write a matlab script to simulate a frequency selective fading channel. these are very helpful. Reply leslie April 24.com/2008/08/10/ber-bpsk-rayleigh-channel/ 45/50 . 2010 at 5:19 am @Ok. you may try to create a packet error rate simulation environment with the above mentioned parameters. In the OFDM case.12/9/13 BER for BPSK in Rayleigh channel As a first step. 2012 at 6:00 pm What is BEM channel ? Reply Krishna Sankar March 12. if u could do it for me i would be very thankful to you. and we quantify the quality of each channel by its average received SNR. though the total channel is a frequency selective channel. Are you using OFDM? Reply khurshid September 7. Reply JERRY April 7. Rayleigh fading that remains constant over each source block (quasi-static fading). thanks Reply Humayun March 10. Reply Krishna Sankar April 27.It is great to simulate the Jake’s channel model. The channels between users (interuser) and to the base station (uplink) are mutually independent with flat. please help me to solve the following writing the matlab code. 2010 at 7:45 pm You may use the BEM channel model for it. thanks khurshid Reply lealemta August 21. 2008 at 12:09 am hello! i go through your posts of matlab code. 2008 at 1:36 pm Thank you! Kirishna. Am expecting that a rayle expected BER performance in OFDM will be the same as the results obtained in the above plot. the above simulation is for a flat Rayleigh fading channel. Each receiver has perfect CSI and employs coherent detection. if more detail is needed please inform me… it is very urgent for me. for example a channel of 120 Hz Doppler frequency. Assume BPSK modulation with equal user transmit powers. 2009 at 5:35 pm 您好 请问最后的误码率公式是怎么化简得到的？能给指点一下参考书吗 谢谢 www. We use the RCPC code fam and choose overall code rate R = 1/4 with source block size K = 128 bits.dsplog. I will run simulations to check and confirm. 2012 at 4:42 am @Humayun: I have not tried to simulate BEM channel model Reply Krishna Pillai August 21. Will you be able to help me generate a code for 2×2 MIMO equalised using thanks in advance. http://www. 2010 at 7:09 am @Ali: The BER for BPSK in AWGN can be found @ http://www. MANY THANKS Reply Krishna Sankar July 26. Thanks for the reply ! Well as we have detailed information about rayleigh fading channel on this link http://www. Im just learning about mimo equalization and all. 2010 at 8:05 am It’s useful~~Thank you! Reply ALI July 25. you may use the MIMO with Zero Forcing Equalizer as the most simplest example. did you mean pre-compensin experienced by the MIMO channel is diagonal? [U S V] = svd(H) Reply leslie April 25. as i have already gone through the link which you have posted me unfortunately i couldn’t find what exactly i am Thanks Reply Krishna Sankar July 27. When you said.dsplog.dsplog. 2010 at 6:47 am @Ali: You may refer posts @ http://www.dsplog. Meesserschmit. Lee. Reply balaji May 27. 2010 at 3:32 pm Hi Krishna . 2009 at 6:38 am @JERRY: You may refer to the post on Derivation of BER for BPSK in Rayleigh channel for the proof.12/9/13 BER for BPSK in Rayleigh channel Reply Krishna Pillai April 11. I have not written anything on Rician channel as on today.dsplog.com/tag/mimo In those posts.com/2008/08/10/ber-bpsk-rayleigh-channel/ 46/50 .com/2007/08/05/bit-error-probability-for-bpsk-modulation/ Sorry. www.dsplog.3 of Digital Communications by Barry. equalizing MIMO by SVD.dsplog. cheers. You may look up them @ http://www. 2009 at 8:34 pm @balaji: I have written some posts on MIMO. 2009 at 7:09 pm Hi mate… i went through your code and it was great. this is discussed in Chapter 11. i need few matlab codes oF MIMO AND SISO SYSTEMS ON AWGN FADING CHANNEL AND RICIAN FADING CHANNEL. 2010 at 11:54 pm hi.com/2008/08/10/ber-bpsk-rayleigh-channel/ can i have a similar information about rician and awgn.com/2009/01/22/derivation-ber-rayleigh-channel/ Further. Reply Krishna Pillai May 31.com/tag/mimo These are flat faiding Rayleigh channel Reply Ali July 26. 2 author names have already been included. BER BPSK OFDM in raileigh channel should be better than BER BPSK in Rayleigh channel? Explain? Please. Thank you!!! Reply Researcher Publication Opportunity August 21. 2010 at 6:35 pm Khishma. After the paper is accepted and the client is conformed about the acheivement. Candidate name will be included in Paper after milestone payment is released by him/her. Interested candidates who want to include his/her name at 3rd position will be required to pay for the reg Matlab Code as well as the full paper will be sent to the individual after acceptance of paper from the conference.dsplog.com/2008/08/10/ber-bpsk-rayleigh-channel/ 47/50 .12/9/13 BER for BPSK in Rayleigh channel Krishna Sankar July 27. the channel changes every symbol Reply FERNANDO March 12. 2010 at 4:54 pm Khishma.com. only then he will be allowed to pay. 2010 at 7:09 am @Ali: The BER for BPSK in AWGN can be found @ http://www. please. 2008 at 6:11 pm I have seen the simulation code which u used to simulate a Rayleigh fading channel.dsplog. OFDM can handle mutipath channels better http://www. Time is short so the policy of 1 Reply Krishna Sankar December 23. 2009 at 5:46 am @giro82: In this simulation.dsplog. Reply FERNANDO March 12. 2011 at 1:01 pm One who is interested in including his/her name in 3 research conferences in international IEEE conference should reply on email address me_researcher@yahoo. Reply Reply Krishna Sankar March 28. Fee submission will be through Freelancer and elance.com/2007/08/05/bit-error-probability-for-bpsk-modulation/ Sorry. But i would like u to ask a hit how to simulate a frequency selective Rayleigh fading channel for OFDM Rayleigh fading.com/2008/08/26/ofdm-rayleigh-channel-ber-bpsk/ Reply Leave a Comment Name * E-mail * Website www. Thank you very much. BER BPSK OFDM in raileigh channel should be better than BER OFDM in Rayleigh channel? Explain? Please.dsplog. 2010 at 3:44 pm @FERNANDO: Due to the cyclic prefix.com/2008/02/17/cylcic-prefix-in-orthogonal-frequency-division-multiplexing/ http://www. please. Both papers will be included in each Paper. I have not written anything on Rician channel as on today Lealem Tamirat August 19. Thank you very much. Milestone payment is one which is i not in the custody of either party. .12/9/13 BER for BPSK in Rayleigh channel Notify me of followup comments via e-mail Submit { 7 trackbacks } BER for BPSK in OFDM with Rayleigh multipath channel MIMO with Zero Forcing equalizer BER for BPSK in Rayleigh Channel « Overblaze’s Impact MIMO with MMSE equalizer BER for BPSK in ISI channel with Zero Forcing equalization BER for BPSK in ISI channel with MMSE equalization Noise Variance N0 of AWGN Previous post: Negative Frequency Next post: Receive diversity in AWGN Connect with us Enter your Email here.com/2008/08/10/ber-bpsk-rayleigh-channel/ 48/50 .. 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