Binary antipodal signal
With Binary Phase Shift Keying BPSKthe binary digits 1 and 0 maybe represented by the analog levels and respectively. The system model is as shown in the Figure below. The transmitted waveform gets corrupted by noisetypically referred to as Additive White Signal Noise AWGN. The conditional probability distribution function PDF of for the two cases are Assuming that and are equally probable i. Similarly the probability of error given is transmitted is the area in green region Given that we assumed that and are equally probable i. Reply supas: Replies ideally, one would want to give different noise realization for each snr point. But how about real noise? I look forward to hear from you soon. Draw a graph of four curves that show deviation of spectral frequencies from the center frequency for the above four scenarios. Is yours exactly the same thing that I want to do? However, in my design, there are two integrators. Also, if we use lowpass filter, instead of AWGN is there a change? Reply Hi ,I need program for BER reduction using SSPA solid state power amplifer model. Reply Yamsha: To get confidence in the simulated results, one need to get sufficient number of errors. Reply Thats the information that i need! Reply Reply Im trying to draw the same function, BPSK with AWGN, in excel. I get a completely different graph, so i must be doing something wrong. Using gamma-gamma channel model. And the Energy per bit Eb? Comment Reply Reply Reply Manoj: This post and the matlab code on BER of BPSK in AWGN is addressing most of your queries. Reply pawan: you can either use the visual information from the ber plot to find the minimum snr required to hit a given bit error rate. One can also use the erfinv function. Actually, I want to describe the signal between BER and transmission distance for BPSK in AWGN channel. Please give some advices for this. The path loss depends on the square of the carrier frequency and square of the distance in free space. The receiver noise power depends on the bandwidth of the receiver. But I binary not explain why BER can signal be greater than even the distance is increased up top very large value. I think that this result is not suitable with the fact that when BER will be increased to 1 when distance increased from 0 to infinite. Note that the input symbols are equiprobable, and there is no need to generate individual bits. The detector finds the closest point in S to r. Reply Anil: Long back, I have written a post on symbol error rate for 4-PAM. Reply megha: what is chaotic switching? Is nErr ii an array? The following is confusing. Reply Zoe nErr is the count of errors. I have tried doing the spreading and the despreading as well as noise addition but the BER vs. EbN0 curve is higher!!!! However, if you are getting zero BER for no noise case, it points to a scaling error. Reply Krishna: Hello Krishna I have tried the no noise case and gave me zero BER. Do you have any code for spreading and despreading? I need the correct coe for binary final project on my Bachelor degree. So I should be very grateful if you can help me with this. Reply pleas Mr I would like to help me to find calculation BER vs SNR when using 64DAPSK modulation with DWT-OFDM in simulation MATLAB, thanks. Reply Reply Your article really open my eyes. Is there anyone about calculate theory BER value of frequency selective channel in your BLOG? Thanks, Yushi Chen Reply Fargo: Thanks. Krishna Would you help me in my project!!! I study this paper in IEEE for satrting my thesis in master degree. The first problem is finding average SNR in mode n. Idea is to find the area under the tail of the Gaussian curve. Reply I am having problems simulating the BER vs SNR curve for the binary on-off keying modulation. My plot looks backwards. Do you have any suggests. I need ur guidelines to work in communication field or in signal processing so that I can prepare for my future… Pls do reply waiting for ur precious reply. Thank You Reply Thiyagi: All the best for your studies. You can check couple of points: a awgn : whether the noise power is as expected. That piece of code looks funny. Did not understand the need for ber and ber2. Should be easy for you to figure out. Thanks in advance Reply Reply In fact sir Krishna Pillai want to make noise variance equal to 1 or 0dB. I also noticed that this scaling antipodal for system to system e. Your post save me a lot of time to focus on the real subject of my work. Thank you very much for the help! Reply Reply hi krishna, please send the matlab codes whatever u have about that paper for below linked paper, I am doing my project on that paper. This antipodal very urgent. I am badly needed BER code of QPSK, QAM 16,64 with AWGN channel. I am hoping to design a OFDM communication system… If you were to design an OFDM communication system. Regards Sara Reply Reply what about 8-PSK? Reply Reply Oops i am sorry if this is a total blunder. In digital modulation techniques we modulate a sine or a cos wave using bits and transmit them as sine or cos waves. But in this code for BPSK modulation I never found the usage of such things. There are two aspects to the reply. Hence did not put those in place. Thanking u sir Reply rama krishna: Adding complex noise does not affect the end result as we are ignoring the imaginary part at the receiver. However, just make sure that scaling is correct. Reply STIVE CHLEF: Well, if you have users, how are you planning to distinguish them at the receiver? Reply fizzle: Well, if you divide signal power by noise power, the resultant is signal to noise ratio Reply your kind guidance on MATLAB has been really a great help for MATLAB starters. Reply Reply Hi, Can anyone help me in my project!!! But my project guide has told me to mathematically prove that BER vs SNR is better for OFDM using BPSK than simple BPSK. Suppose there is N no. Reply Reply hello sir, m doing ma project on ber calculation using matlab simulation for ofdm transmission for multipath wireless communication so please if u cud help me out in knowing which book wud b d best 2 go through…. Reply Ananya: A good book to read is OFDM Wireless LANs: A Theoretical and Practical Guide by Juha HeiskalaJohn Terry Reply hello sir, please give us an idea how to analyse matlab code for ofdm-awgn channel with that of theory. Reply rekha: The BER performance of OFDM in AWGN is comparable to the no OFDM case. Reply Can you little bit tell me how to simulate the Uncoded BER and ergodic capacity for webb channel using QPPM modulation. Reply haiiiiiii i need Matlab code for digital modulation techniques. But, when i applied my SNR into your coding for simulation, i got the problem. I think that problem occurred at SNR or BER. But i dont know where my coding is problem? Can you help me pliz… Thanks a lot. Reply fatima: I believe it should be reasonably straightforward to modify the gaussian channel used in this post to a binary symmetric channel. Using MAT-LAB plot bit error probability BEP under non-coherent de-tection. Reply Obinna O: Hope you have finished the project by now. Reply I am working on an adaptive modulation model on Simulink. For that first I am trying to get probability of error rate vs snr of different modulation techniques. On modelling 16 QAM modem I have problem plotting its graph by getting bit err rate from simulink model and performing graph plotting on matlab. Can u suggest me a Block for finding Pe or a Program to call from. Reply Jatin: Does this help? Since you have also worked on similar field, I hope u can help me. I was stuck with re creating the 1st fig in the paper. SO, can you please look into it and help me out. Pls i will appreciate ur reply. Reply Reply Hi Krishna. Thank you very much. God will bless you. Pls, you are indeed a very good teacher, help me out Reply Hi Krishna. Pls, you are indeed a very good teacher, help me out Reply Egerue: You are right. Want to know if is how one can plot for BER with variable noise in the channel. I will appreciate if you reply me soon. Thanks Reply Egerue: Do not change the division factor. The division by 20 is required to convert dB into voltage. Reply Reply 3mor: If the probabilities are un equal, we would want to shift the threshold for making the decision. The chapter Digital Communications by John Proakis discuss that case. Reply This Krishna Pillai guy is a great help and his website undoubtedly very good resource on communication system topic. I got necessary informations about Vitervi Algorithm, Antipodal and soft decision. Reply Reply Dear Krishna: I knew that OFDM technique, improve the BER performance in frequency selective fading channel, Can you help me in writing code using matlab program show thatI have probem in how write code for frequence selective fading. Reply I knew that OFDM technique, improve the BER performance in frequency selective fading channel, Can you help me in writing code using matlab program show thatI have probem in how write code for frequence selective fading. Reply ahmed: In OFDM, though the channel is frequency selective, channel as seen by each subcarrier is flat. Hence the expression for flat fading holds good. So, we assume that receiver is unknown h matrix and we must explore channel by channel estimation. Do you help me? Hope you will response me! Reply Reply Reply Reply Reply I am working on Forward error correction codes. I have plotted the BER performance curve for Reed solomon codes using BPSK modulation over an AWGN channel from EbNo 0 — However, the curves are overlapping at the begining between EbNo values 0 and 1 and also in the middle. Also the curves for convolutional codes overlap at the begining between 0 and 1. Could you please give me a detailed explanationc on the reason why the overlapping occurs and the significance. The RS codes used were RS 255,191RS 255,223RS 255, and RS 255, Thanks, hope to hear from you soon. Reply Tito: Firstly, a clarification. At-least with respect to convolutional codes, I think it can be attributed to the large number of errors in received coded bits, which makes the Viterbi algorithm go haywire. Reply Thanks that is exactly what i mean. Why does this occur. And i also have an curve RS curve with and without an interleaver, these curves are overlapping at two points. Reply hi,can any one help me to derive BER for physical layer network coding PNC modulation scheme… Reply Reply Reply Reply I would like to ask you a simple question. I am trying to make a simple simulation using a matlab. Reply Reply Hi, my english is not very good looking, but…what is the noise variance for 16QAM and 64QAM? Reply Diego: The noise variance is independent of the modulation scheme. However, I think you might be looking for error rate for different modulation schemes for a given value of noise variance. What is the model of the multipath channel? Reply Hi, I am want to plot the pdf for various SNR Symbol Error for various modulation schemes. Do you have matlab code for it. My question is very poor, nevertheless i will wait for your comment Have a nice day Reply Moon: My replies Before this scaling, the signal term s and the noise term n has the same variance of 1. This is equivalent to having factor. Reply Can someone help me out with a Matlab code for this. Thanks to you, I just realized that it is used in DVB-S2. I will try to do a write up in future. Reply Reply Mathew: Did you mean 16-PSK? I am plotting BER for BPSK and QPSK but i am not getting same BER curve. As it should be same for both. I know that the plot should be BER vs EbN0. But how to get EbN0 from SNR? I think it is SNR. Reply i have a question. Reply Eduardo Solano: If the simulation curve is happening to the right of the theoretical curve, it typically means that you are adding more noise than what is required. Reply maya: Well, try to write the equation in matrix form. For eg, consider a simple case where we have two transmit antennas and 3 receive antennas. Reply HEY sir can u plzz help me in getting the main concept of vblast detection scheme,i am not geting how it estimates the data… Reply maya: Well, understanding V-BLAST with Zero Forcing equalization is the most simplest way. From our linear algebra days, we know that if we have two unknowns, we need atleast two equations to solve them. Adapting them to MIMO V-BLAST, the two unknowns are the unknown transmitted data, and the two equations are provided by the two receive antennas. The following post might be of bit more help. I am in 5th semister of my bachelors of telecommunications. So I am new to this field and facing lots of difficulties. I find your site very impressive and have joined it recently. Can you kindly tell me why we normalize things? We normalize, because we want to have a fair comparison when trying out different approaches…. For eg, if we are comparing 100apples with 100grapes, we would want to know the price per kilogram, no? Reply Dear Krishna how can we simulat the angular delay profile. Reply Reply i am doing my project in cdma can u tell me the purpose of rake receiver and details about maximum ratio combining Reply kanchana: Well, I have not quite discussed about cdma in the blog till date. Hope to do so in future. I beleive the intent of the rake receiver is to coherently combine information from all the multipath taps such that the bit-error rate is reduced. I have posted about maximal ratio combining for a 1 transmit 2 receive receive diversity case. Reply Reply Reply Student: I just did. Hope you are happy with the response. Sorry for the delay in my reply. At the receiver you cmay undo the effect of the sine wave by multiplying the received signal with the sine wave and taking the mean. Then perform hard decision decoding on that signal. Reply Hi, I would need equations of bit error probability for this modulation technique: MSK, GMSK, QPSK, ASK. Do you know it? Something to do in future. I mean reteriving back of binary code. Reply Please i dont know how i can acess the e book. I am working on super orthogonal space time turbo codes in OFDM systems and will need this e book. I signal for a positive response. Maybe the post on symbol error rate computation using 4-PAM be of help. Consider three combining schemes: MRC, EGC and SC, for plot the BER versus the average signal-to-noise ratio SNR. I hope you can help me Reply R y: Using BPSK modulation, I have written articles for a 1 transmit, 2receive system in a flat fading uncorrelated Rayleigh channel. Reply All your posts have been very helpful and binary understandable. I was looking for a code that has all the modulations bpsk,qpsk,mpsk,ask,bfsk,msk etc… in a single program and to compare their BER, PSD curves. Reply Murali: No, I have not posted a single code putting all the BER curves in a single plot. Reply Reply A randomly generated bit stream should be transmitted through an AWGN channel using Binary. THe received symbols should then be converted again to a bit stream. The received bit stream should be compared with the original one to determine the total number of errors and hence the bit error probability. Once the above system is succesfully simulated an additional block of channel coding should be incorporated in the system. A 15,11 Hamming code should be used for this purpose. Reply Reply Reply Reply Did you find material about calculate throughtput for a multi-hop wireless network using matlab? Please share me if you have. Reply Reply Could you go in to a signal more detail why you use complex noise vs. In my simulation, if I use 10 instead of 20, my results were way off, but 10 gives a perfect match with theory. Reply Matt K: My replies Yes, for BPSK the noise component on the imaginary arm is ignored. To make the noise model same as with other modulation schemes, I kept it as complex The division by 20 is to convert the dB to scale the voltage signal. In my simulation model, the noise term n is a Gaussian random variable with mean 0 and variance 1. Thats why I used In general, it depends on how one creates the model. Different people have different coding style. However, its the end result which matters Reply tq krishna…i understand it more than before. Reply nyna: The shape of the curve is determined binary the probability of error signal we have defined signal the post. Reply I am new here. I find this site really very useful. I have a question reg BPSK sim. I did it with awgn function and I am not getting theo and sim binary overlapping. Please answer this as soon as you get time. Is the slope of the graphs matching. Then its quite likely some power normalization issue. Reply Reply Reply krishna can u help to understand more about the function of transmitter filter in BPSK and also how the ISI intersymbol interference will occur at transmitter filter?? Reply nyna: In the transmitter, we will first be converting bits into analog voltage in the case of BPSK. However, we cannot transmit them as is, as it will occupy lots of spectrum which is not desirable. Hence we need to do filtering. However, when doing filtering, we introduce ISI inter symbol inteference i. So, the question is: can we do filtering without introducing ISI? The answer is YES. There are simple filters like rectangular, ideal filter like sinc and practical filters like raised cosine, which can do the job. What the purpose of finding the value of delay in the program of BPSK? Reply nyna: Filter is used for controlling the spectrum of the transmission. However, signal doing the filtering we do not want to introduce ISI. Hence we typically go for filters like raised cosine etc. I mean why we need to scale the noise power as per the defined bit to noise ratio? Any references will help me a lot fire back soon plz!!! Reply invizible soul: Sorry for the delayed response. I am traveling with out a reliable access to internet. In this analysis, our objective is to analyze the impact of noise on the reliable decoding of BPSK modulation. To analyze the impact, we need to antipodal out the performance bit error rate for different values of noise. Hence we scale the noise by noise power. Reply Reply Reply bullah: It depends on the coding which is applied. There are couple of posts discussing BPSK in AWGN with rate convolutional coding. In typical systems, we experience white noise filtered by an ideal LPF. The variance of this filtered noise contributes to the noise term in the system. You may look at chapter 9 in Communication Systems — An introduction to Signals and noise in Electrical Communication by A. Bruce Carlson, Paul Crilly, Janet Rutledge for further details. Hope this helps Reply Ideal: It just means that any value of y real component greater than 0 is assigned to 1 and if less than 0 is assigned as 0. This is called hard decision decoding. Soft decisions — where we do not decide on what antipodal transmitted based on the received constellation — are used typically when there is signal decoder block like Viterbi following the constellation demapping. This should be a reasonably easy aspect to resolve. Reply I have made a antipodal for BER of BPSK in AWGN and Rayleigh fading channel, now I want to combine the both results in one graph, when I combine the results, the curve for rayleigh change but for awgn not change, can you give any idea what should i do, either i make a functions of both separately and call in one program or i should do something else? Reply Antipodal Stradlin: There is noise on the real and imaginary dimension. So, to make the total variance of the complex noise to unity, there is scaling by Reply Reply Reply grad student: Yeah, thanks for the suggestion. I agree that your proposal will make the text even more readable. Anyhow, may I recommend to keep status quo given that the current text is not making it very difficult for the reader. Reply Might want to consider using a separate integration variable for the definition of the erfc function, since the variable x was used for both the erfc argument and integration variable. I do not have the codes, but I would think that it will be reasonable to extend the available simulation models to 16QAM case. Do you have the matlab code for OFDM with 16-QAM in AWGN and Rayleigh Channels. Best Regards Hussien Reply Micman: Thanks. I signal written a post on symbol error rate computation for QPSK in AWGN. Do you have the matlab code with qpsk symbols? I want to compare the theoretical bit error curve for qpsk with a simulated bit error curve with a zero force equalizer. Can you please give me an advice of how to implement this. Reply siddhartha: I have written a post on Coherent deomdulation of DBPSK Differential Binary Phase Shift Keying. OFDM can be thought of as a simple up-conversion scheme where each information gets multiplied on different sub-carrier frequencies. So please give me the idea by differentiate the two curves and how the BER can be decreased with OFDM as soon as possible. Infact if you see the simulation model, for demodulating the symbol, we use only the real part of the received signal. Reply I do not understand why a complex gaussian noise is required. The source here belongs to a BPSK modulation so I think, in practice we have a real noise, because we do just activate the in phase component and not the quadrature phase component. The code is present in this post. I believe you are looking for the code for transmit pulse shaing filter. Anyhow attaching the link again Please click here to downlod Reply Reply Jhony: If I may put very briefly, fading is the characteristic of the wireless channel. The channel read enviornment will vary with time and will exhibit different behaviour for differnt frequencies. One of the most simplest and useful model of fading is to visualize it as filter whose binary change in time. Signal, this is a simplistic description. For a detailed overview, may I recommend chapter 2 from the book Fundamentals of Wireless Communication — David Tse, Pramod Viswanath Reply hi i hope you are in good health. Can you please tell me what a fading co-efficient is? I shall be very thankful to you. I am thankful to u for helping me Reply Jhony: The randn function generates a random variable having Gaussian distribution and the spectrum of this random variable is same across frequencies. Hence the name White Gaussian Noise WGN. Glad to notice that you are not desperate now Typically, to keep the code simple, I tried to avoid in-built functions. The link to the code is under the heading Simulation model. Anyways, for BPSK it is simple. We observe the real part of the received symbol. Reply Hey, I found theBit error curve for BPSK modulation — theory, simulation very useful. Could you please send me the syntax matlab comand of QPSK modulation for OFDM under multipath i. Very thanks in advance. I have not checked for FSK modulation. Once I understand, hopefully will be try put together a post. Reply srinivas: It is not double the bit error. Infact the BER result with BFSK is 3dB poorer than BPSK. Do u have any code regarding this problem? Both papers are related to mobile communication. Total of 3 authors list will be included in each Paper. Matlab Code as well as the full paper will be sent to the individual after acceptance of paper from antipodal conference. Fee submission will be through Freelancer and elance. Milestone payment is one which is in the custody of broker Freelancer or Elance authority and not in the custody of either party. After the paper is accepted and the client is conformed about the acheivement, only then he will be allowed to pay. Time is short so the policy of 1st come 1st serve will be entertained. Reply I have written a post on symbol error rate and bit error rate for 16-PSK. Reply Ali: The 0dB variance is for complex noise on both real and binary part. For BPSK we use only real part and the variance is Agree? Reply hemant: Sorry, I have not worked on LAS. Infact, I was unaware of the acronym till I googled and found Large Area Synchronous. Reply Hi Krishna, I just read your answers in this website. I am working in convolutional codes with 8psk and AWGN. I have some doubts in Iterative decoding. Can you help me. I was stuck with re creating the 1st fig from the paper. Can you please look binary it and help me. Reply Never mind, already found out what I did wrong… forgot to convert to dB scale Reply khushi: in this post … Reply I have to give a value to bit rate Tb and observe the effect of this variable on probability of error by changing it. My graph must be error versus bandwidth by accepting noise as zero. Do you have such a code? Reply Ozgee: If the noise is zero, do not expect the bit error rate to change with bandwidth. However, i do not have such a code. Thank you very much! Yamsha Reply Yamsha: To get confidence in the simulated results, one need to get sufficient number of errors. Thats the information that i need! Reply phani: sorry, do not know about ofdm-idma topic Reply Dear Mr Krishna. Im trying to antipodal the same function, BPSK with AWGN, in excel. May i contact you by mail to send you my table?. Comment Reply Dear krishna sankar sir, could you please help me regarding the question i posted Reply Manoj: The matlab code in this article should be able to address most of your queries Reply Manoj: This post and the matlab code on BER of BPSK in AWGN is addressing most of your queries. One can also use the erfinv function Reply can you exaplan about curve of error performance antipodal BPSK over AWGN and Rayleigh channel? Thank binary so much!! I think that this result is not suitable with the fact that when BER will be increased to 1 when distance increased from 0 to infinite I hope you give me some advices for this. Your cooperation in this regard will highly be appreciated Thanks Anil Reply Anil: Long back, I have written a post on symbol error rate for 4-PAM. However, if you are getting zero BER for no noise case, it points to a scaling error Reply Krishna: Hello Krishna I have tried the no noise case and gave me zero BER. So I should be very grateful if you can help me with this Reply pleas Mr I would like to help me to find calculation BER vs SNR when using 64DAPSK modulation with DWT-OFDM in simulation MATLAB, thanks Reply yahya: Sorry, I have not tried 64DAPSK antipodal Reply Your article really open my eyes. Idea is to find the area under the tail of the Gaussian curve Reply I am having problems simulating the BER vs SNR curve for the binary on-off keying modulation. Greg Reply Greg: Are you getting zero BER when no noise is present in the simulation? So, all your issues are resolved? In fact sir Krishna Pillai want to make noise variance equal to 1 or 0dB. And do you have code on how to generate the eye diagram. Regards from Brazil Marcos Amaral Reply Marcos: Thanks Reply hi krishna, please send the matlab codes whatever u have about that paper for below linked paper, I am doing my project on that paper. I have to submit my paper on 30may please send me codethis very helpful for me. Regards Sara Reply Sara: You should know your available bandwidth, then chose your subcarrier spacing and so on Reply Hi Krishna, what about 8-PSK? Reply weather: Thanks for noticing the typo in the comment. I corrected it Reply Oops i am sorry if this is a total blunder. Reply amit: In AWGN there is no difference between using BER for BPSK and BER for BPSK using OFDM Reply hello sir, m doing ma project on ber calculation using matlab simulation for ofdm transmission for multipath wireless communication so please if u cud help me out in knowing which book wud b d best 2 go through…. Hope to do so Reply hi, I would like to demodulate QPSK but using soft decision. TQ so much if you can help me Reply anne na: Why are you using soft decision, unless you have some decoder like Viterbi following your demapper. Reply anis: If we initialize, we can ensure that the same random numbers are generated in any run Reply Hi binary I need matlab code to obtain BER vs SNR curve for binary on-off keying. Reply dear krishna… In theory, when i applied my SNR into your coding, i got the result. I will try to answer to the best of my knowledge Reply Hi Krishna, Actually, im studying about your coding for BER vs SNR for BPSK modulation. Reply adah: What is the error which you are getting? Reply rai: No, erfc is not equal to Q function, but both are related. Thanks a lot, i will be very grate ful to get help from you guys Reply Obinna O: Hope you have finished the project by now. Since you have also worked on similar field, I hope u can help me I was stuck with re creating the 1st fig in the paper. SO, can you please look into it and help me out Thanks, Student Reply student: Sorry, due to time constraints, may I pass that opportunity. Pls, you are indeed a very good teacher, help me out Thanks, you are really very helpful, you must really reap the fruit of your efforts. NNAMDI Reply Hi Krishna. NNAMDI Reply Egerue: You are right. The division by 20 is required to convert dB into voltage Reply Hi Krishna, thanx a lot for your website i have a simple question: what about the unequally probable, e. Reply 3mor: If the probabilities are un equal, we would want to shift the threshold for making the decision. Ajay Pratap Singh apts Reply Ajay: Thanks for the nice words Reply Dear Krishna: I knew that OFDM technique, improve the BER performance in frequency selective fading channel, Antipodal you help me in writing code using matlab program show thatI have probem in how write code for frequence selective fading. Thank binary Reply I knew that OFDM technique, improve the BER performance in frequency selective fading channel, Can you help me in writing code using matlab program show thatI have probem in how write code for frequence selective fading. Thank you Reply ahmed: In OFDM, though the channel is frequency selective, channel as seen by each subcarrier is flat. Reply Hung: Yes, the receiver is trained to estimate binary MIMO channel by sending known preamble Reply Thanks a lot, man. Was very useful Reply can you send me the matlab coding for physical layer network coding modulation Reply thenmozhi: Sorry, I do not have matlab code for physical layer network coding modulation Reply Hi Krishna, I am working on Forward error correction codes. The RS codes used were RS 255,191RS 255,223RS 255, and RS 255, Thanks, hope to hear from you soon Reply Tito: Firstly, a clarification. At-least with respect to convolutional codes, I think it can be attributed to the large number of errors in received coded bits, which makes the Viterbi algorithm go haywire Reply Thanks that is exactly what i mean. Why does this occur Reply hi,can any one help me to derive BER for physical layer network coding PNC modulation scheme… Reply Selvadenniz: Sorry, have not studied PNC coding Reply hiii… you have BER for physical layer network coding PNC modulation scheme… Reply tommy: Sorry, no Reply Hi Pillai I would like to ask you a simple question. Reply hi can you tell me how to make adaptive modulation? Do you have matlab code for it The derivation in this link is SER Vs SNR, How to change the SER to PDF of SNR? Can u help me in this regard? Thanks in advance Reply Olguin: Well, having BER of means there is some error in the simulation code. I need matlab code for DPSK and also its BER. I will try to do a write up in future Reply Have you got any code to 16-apsk? Reply Mathew: Did you mean 16-PSK? From our linear algebra days, we know that if we have two unknowns, we need atleast two equations to solve them Adapting them to MIMO V-BLAST, the two unknowns are the unknown transmitted data, and the two equations are provided by the two receive antennas. Reply Ideal: Sorry, am not familiar with modeling angular profile Reply hello sir i am doing my project in cdma can u tell me the purpose of rake receiver and details about maximum ratio combining Reply kanchana: Well, I have not quite discussed about cdma in the blog till date. I am really happy and trying to do what u have suggested Reply Dear Krishna Pillai : Please reply my question dated April 30, at am. Regards, Reply Student: I just did. Thank u Reply Oluwafemi: I had mailed you the instructions. Thanks Reply Einsein: I have written a post on BER computation for FSK using coherent demodulation. Thanks Reply Murali: No, I have not posted a single code putting all the BER curves in a single plot. Simulation of this should be performed to increase the performance of the system. Thanking you Reply Nafis: Antipodal BPSK. Reply Hi there, very useful site. I have a couple of questions regarding the BPSK Could you go in to a little more detail why you use complex noise vs. Thanks much, Matt Reply Matt K: My replies Yes, for BPSK the noise component on the imaginary arm is ignored. However, its the end result which matters Hope this helps Reply tq krishna…i understand it more than before. Reply nyna: The shape of the curve is determined by the probability of error signal we have defined in the post Reply Hey krishna, I am new here. Then its quite likely some power normalization issue Reply hi I wanna matlab simulation code for AODV routing protocol. Can you help me … Reply shoumi: Sorry, I have not worked on AODV protocol Reply krishna can u help to understand more about the function of transmitter filter in BPSK and also how the ISI intersymbol interference will occur at transmitter filter?? Plot the BER vs. EbNo Reply Einstein: Sorry, I do not have Matlab simulations with GFSK. I am traveling with out a reliable access to internet In this analysis, our objective is to analyze the impact of noise on the reliable decoding of BPSK modulation. Reply bullah: It depends on the coding which is applied. Reply Hi all hope u all r f9 can any one help me for BER performance of adaptive modulation QPSK,4QAM,16QAM in AWGN only I need to draw them in single graph thankz in advance Reply mak: As I understand from your query, you want to switch from one modulation scheme to another based on a defined error rate constraint. This is called hard decision decoding Soft decisions — where we do not decide on what was transmitted based on the received constellation — are used typically when there is a decoder block like Viterbi following the constellation demapping. Hope this helps Reply Dear Krishna, I have made a program for BER of BPSK in AWGN and Rayleigh fading channel, now I want to combine the both results in one graph, when I combine the results, the curve for rayleigh change but for awgn not change, can you give any idea what should i do, either i make a functions of both separately and call in one program or i should do something else? Thanks alot Reply exelent! Reply grad student: Yeah, thanks for the suggestion. I agree that your proposal will make the text even more readable Anyhow, may I recommend to keep status quo given that the current text is not making it very difficult for the reader Reply Nice graphics and derivation. Might want to consider using a separate integration variable for the definition of the erfc function, since the variable x was used for both the erfc argument and integration variable. Thank you in advance Best regards Micman Reply siddhartha: I have written a post on Coherent deomdulation of DBPSK Differential Binary Phase Shift Keying. Hope this helps Reply hey krishna, can you please help me with the case of DPSK Reply farie: The demodulation approaches for PSK is a different from QAM. The source here belongs to a BPSK modulation so I think, in practice we have a real noise, because we do just activate the in phase component and not the quadrature phase component Reply hi, hope every1 doing well. Btw, what is pulse sampling? Anyhow attaching the link again Please click here to downlod Reply please send me a source code for bpsk modulation in matlab Reply Jhony: If I may put very briefly, fading is the characteristic of the wireless channel. The channel read enviornment will vary with time and will exhibit different behaviour for differnt frequencies One of the most simplest and useful model of fading is to visualize it as filter whose coefficients change in time Ofcourse, this is a simplistic description. Hence the name White Gaussian Noise WGN This is then Added to the signal, hence the name Additive White Gaussian Noise AWGN … Reply yeah! The link to the code is under the heading Simulation model Anyways, for BPSK it is simple. How do we demodulatedecode and compare it with the input signal Reply shareef: Thanks. The next post is planned to be on OFDM Reply thanks alot or this article. Reply Dear Krishna, Your simulation and theory prgram is very usefull and helpfull. Feeel the difference Reply srinivas: It is not double the bit error. Can you please give a possible MATLAB code. Good luck I want to change the spatial resolution in dots per inches of an image. Time is short so the policy of 1st come 1st serve will be entertained Reply RAO: My replies; I have written a post on symbol error rate and bit error rate for 16-PSK. Infact, I was unaware of the acronym till I googled and found Large Area Synchronous Reply Hi Krishna, I just read your answers in this website. Anil Reply anil: You may ask. Since you have signal on similar field, I was hoping you can help me. Student Reply Never mind, already found out what I did wrong… forgot to convert to dB scale Reply khushi: in this post … Reply I have to give a value to bit rate Tb and observe the effect of this variable on probability of error by changing it.
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