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{ 109 comments… read them below or add one }
i am already a member so how can i download this book???
@upasana: I just mailed you the download instructions. Plz check.
hi krishna,
can you suggest practical values regarding various parameters of rayleghigh faded channel for various conditions. i.e. flat faded, frequency selective etc.
another problem is related with the matlab that, how to calculate the time taken for execution of any program.
@rochak: Well, whether the channel is flat fading or frequency fading depends on the transmit symbol duration too. If the duration of the symbol is more than the duration of the channel, the channel is flat fading.
You may also want to check http://en.wikipedia.org/wiki/Fading
For computing the execution time in Matlab you may use tic-tac. Put tic before the command you want to execute and tac after the command. It will show the time it took for execution.
i am already a member so how can i download this book???
@Nihar: I just emailed you the download instructions. Plz check.
how can i download the ebook’ ebook on error probability in AWGN’ . i m already subscribed at dsplog.com
@farrakh: I just mailed you the download instructions. Plz check.
hi, krishna pillai, i,m already a member of dsp lo, But i don,t know how can i download the book, can u plz send me the instructions
@kishoredaparti: I emailed you the download instructions. Plz check.
Dear Kirshna
you are doing very well on ur blog .. you uploaded the MRC and transmit beamforing.. MRC is very clear and also it is for multple antennas but transmit diversity SNR is not shown clear and also it is not shown for multiple antennas..
so plz can you show the difference between MRC and MRT in the SNR behaviour and BER in ur coming work. and also show the SNR of MRT for multiple antenas
@lee: I guess, your concern is that the SNR gain in transmit beamforming is not explained well. I will look into the post and add contents, if needed. Thanks for the feedback.
hey krishna,
i couldnt find any help in finding the Modulation error ratio , i have asked with various phd students they said me its impossible and we dont knw bla bla..
i have a signal constellation(or a signal), i passed it through AWGN and received it ,now of course due to AWGN the constellation point will be shifted ,now i want to knw abt the difference between the constellation point before and after awgn,bcz thats how we can find the Modulation Error ratio,
@hassan: Modulation Error Ratio is mean of the difference between ideal and received constellation.
Lets say I0, Q0 are ideal constellation and Ir,Qr are the received constellation, then the MER is
MER = E { (Ir-I0)^2 + (Qr-Q0)^2 }, where E{ } is the expectation operator.
The slides 19-to-25 in the following pdf should be helpful.
http://chapters.scte.org/cascade/SCTE%20CNR%20vs%20SNR.pdf
dear krishna,
thanks for helping me out ,i have two questions first of all how will i detect the position of any constellation on transmitter side, second issue is that on receiver side there will be alot of constellations bcz of noise , imean if a signal is at the transmitter side @ 4.2 on graph then at that point in receiving constellation there will be lots of point of constellation, now i want to knw that how to locate the constellation point in matlab , i knw how to do it maually but dont knw that how to do it by program.
@hassan: My replies:
1/ At the transmitter, we know the type of symbol to send. For eg, in BPSK its {-1,+1}, QPSK 1/sqrt(2)*{+1+j,1-j,-1+j,-1-j} and so on
2/ At the receiver, we define threshold boundaries for determining the transmitted constellation. For eq, if we are using BPSK we keep the
threshold to 0 for determining the constellation i.e any received value above 0 is assumed to be 1, and any received value below 0 is assumed to be -1.
Some of these posts might be helpful
http://www.dsplog.com/2007/08/05/bit-error-probability-for-bpsk-modulation/
http://www.dsplog.com/2007/12/09/symbol-error-rate-for-16-qam/
wants to add in my previous commment question that the contellation after the modulation will be lots of constellation which will be acting like anoise ,so basically i need to knw the difference between the noised( receive constellation ) and the original (transmitted) constellation .
i would like to know that how to plot my signal in the form of eye diagram , if i dnt want to use any toolbox, i have found command on matlab
% Create an eye diagram scope object
h = commscope.eyediagram;
% Prepare a noisy sinusoid as input
x = awgn(0.5*sin(2*pi*(0:1/100:10))+ …
j*0.5*cos(2*pi*(0:1/100:10)), 20);
% Update the eye diagram
update(h, x);
% Display the eye diagram figure
plot(h)
but if u see that the plotting is only for the h , if i have a signal how can i show it in the form of eye diagram.
your early response will be highly appreciated.
Syed
@hassan: For plotting the eye diagram, you need to group the transmit signal into groups of samples for 2 symbol durations and then plot them on top of each other. I have provided a brief example @
http://www.dsplog.com/2008/05/01/eye-diagram-plot-matlab-raised-cosine-filter/
Hope this helps.
Hi,
I have a question about SNR calculation. If we have a received signal y=s+n,
is the SNR E[|s|^2/|n|^2 ] or is it E[|s|^2]/E[|n|^2]?
Thank you very much for your help.
@hande: It is E[|s|^2]/E[|n|^2]?
I am working on ofdm modulation.I am working with simulink.can u please help me regarding this.if u have simulink of ofdm modulator then please do inform.
thanx
@noor: Sorry, I do not have simulink. But, the following Mathworks file exchange link might be of help
http://www.mathworks.com/matlabcentral/fileexchange/3540
Good luck.
hye krishna i want to know that
1- how to plot the SNR in color bcz i need to make compare between different diagram but that diagram in differnt m files snr plotting , so i am thinking to give every snr plotting a color so that i can analyze it , can u help me in that.
2 furthermore i have sent u an email regarding the problem i am facing which is just 1 line error and i am unable to solve it cuz it took me days to me to find out the problem but still unsolved, it is a bit chalenging error.
3 third thing is that krishna i need to knw that i have plottoed different values of SNR vs symbol error rate but krishna i want to knw that for example i am using 4qam modulation on ofdm and i pass a random signal with awgn, rayleigh and racian, now AWGN is giving me error prob(at 8db) of 10(^-1) while rician at 8db is giving me 10(^-2) something , i wanna knw only that lets say i have a random signal passing through awgn, rayleigh and rician at 8db snr , now which channel has to has more symbol error rate , please tell me abt these three channel
like as we increase snr what will happen to awgn , rivcian and rayleigh channel , and which one has has highest sym error rate .
three questions needs ur urgent attention.
@hassan: My replies
1/ Try >> help plot in Matlab/Octave. You will get info on how to plot in different colour, label, etc etc
2/ Is this regarding the LMS equalization? I have not yet looked into it.
3/ AWGN will have the lowest. I do not know the comparison between Rayleigh and Rician.
Hi krishna,
How do i download your free ebook?
@smoodliar: I emailed you the download instructions. Plz check.
Sir,I want to know the calculation for different parameters used in 802.11a standard e.g. T , Delta F, Frequency offset used in OFDM.
@Selvi: Hopefully the quiz
http://www.dsplog.com/2009/10/07/quiz-ieee-80211a-specifications/
might provide you some information.
Hello,
1. How I can download the free e-books, related to BER in AWGN?
2. How I can come to the calculation of the equation
y= s + 10^(-Es_N0_dB(ii)/20)*n; % additive white gaussian noise
that you have written in the program: http://www.dsplog.com/db-install/wp-content/uploads/2008/04/scriptqpsk_ser.m. As in general sence I calculate only the signal is y=s+n;
I am very new in digital communication, please help me.
Thanx.
@Dristy: My replies
1/ I emailed you the instructions
2/ The term 10^(-Es_N0_dB(ii)/20) is to scale the noise voltage. It enables us to achieve the desired signal to noise ratio needed for the simulation. However, in the real world as you said, its y = s + n.
Hi,
Could you tell me how to evaluate entropy H(X+S+Z; X+kS) where ‘k’ is a constant?
@Deepika Balla: Sorry, I do not know
Hi can you please mail the e-book.
Really appreciate that….
Thanks in advance…
@Anirudh: Please subscribe to the email option. You will receive instructions on how to download the eBook.
Hi
I want to measure SER for BPSK and QPSK with same data bits.
N=10 % number of bits
randn(1,N)+j*randn(1,N)
for BPSK as SER=BER
but for QPSK how we make symbol from this data bits:
Thanks
@Abrar: Please refer to the post
http://www.dsplog.com/2007/11/06/symbol-error-rate-for-4-qam/
How do i download your free ebook?
@Pankaj: I emailed you the download instructions.
sir could u pls snd me matlab code for gmsk+convolution interleaving using awgn channel.
i will be very grateful to u…
@baljit: I do not have all of these combined. But you may checkout
http://www.dsplog.com/tag/msk
http://www.dsplog.com/tag/viterbi
Hello Sir,
I am writing code in MATLAB for Rate Compatible Punctured Convolutional Code. I am not getting the required results when I use puncturing, otherwise I am able to match the results for AWGN channel and QPSK and 8 PSK case.
Please tell me how should I depuncture the bits at receiver and what changes I should made in Viterbi Decoder.
Can I use normal viterbi decoder for this case by inserting the zeros at the place of punctured bits.
Suggest me some method. I will explain you in details if you find any problem.
Kuldeep
@kuldeep: Sorry, I have not discussed the Rate Compatible Punctured Codes. Let me try to study the same
Hi,
Now, Im working on link budget analysis simulation. Do you have any article/lecture/matlab code about this topic? because I find difficulties to simulate it..
Looking forward to hear from you..
Thanx
@Nico: Sorry, I have not discussed any articles on link budget simulations
hello sir
ur articles on dsplog.com are very helpful and quite interesting. many
many thanks for those articles. we wish u include many more articles
in the future
sir i shall be thankful to u if u can kindly explain me the
properties of WIDESENSE STATIONARY UNCORRELATED SCATTERING CHANNEL .
also suggest me sites or book names to go through this. I must
transmit bpsk, qpsk, 16psk,16qam symbols through this channel and
estimate the received symbol using kalman filtering
waiting for ur reply
@keerthi: Plz have a look at the post http://www.dsplog.com/2008/07/08/compare-bpsk-qpsk-4pam-16qam-16psk-64qam-32psk/
hello sir
also plz explain me the differences between the properties of awgn
channel and wssus channel((wide sense stationary uncorrelated
scattering channel), I must use matlab for simulation hence ii am in
want of these properties. sir, its a bit urgent plz reply
thank u
,waiting for ur reply
@keerthi: Well, AWGN is an additive noise – added due to the random movement of electrons in the receiver
scattering channel is a multipath channel – multiplicative in nature
Krishna you are doing an awesome job really, brother can you please help me in making my Assignment. the Statement is
compare the BER performance of QPSK, 16-QAM and 16-PSK in AWGN, Rayleigh, and Rician fading channel
i had made a code for QPSK & 16PSK but i m having pd in 16QAM
plz Help me. im waiting
@Syed Asad: Thanks. You can refer some posts on 16-QAM
http://www.dsplog.com/2007/12/09/symbol-error-rate-for-16-qam/
http://www.dsplog.com/2008/06/01/binary-to-gray-code-for-16qam/
http://www.dsplog.com/2008/06/05/16qam-bit-error-gray-mapping/
Hi Krishna,
I have already subscribed, but how shall i download the E-book?
@Ankur: I emailed you the instructions
hi, krishna , i’m already a member of dsp lo, But i don’t know how can i download the book, can u plz send me the instructions
@mawkly: I emailed you the instructions
Hi Mr.Krishna
I Have a basic question. I want to make simulation that compare OFDM and SC in frequency selective fading. How to make SC simulation in selective fading because i think SC still in Frequency domain and i think i can’t convolution every SC symbol with channels coefficient. Single carrier only in flat fading??? Or we can add DFT before we transmit SC symbols through the channels?? I’m confuse
Regards
@Newbie: You can convolve the time domain samples of SC with the multipath channel. The post on BER for BPSK with ISI might provide reference
http://www.dsplog.com/2009/11/29/ber-bpsk-isi-channel-zero-forcing-equalization/
Hi, Krishna. Thank you very much for your nice blog. It helps me solve a lot problems including MATLAB problem.
I’m just curious that lots of people who wrote before said ebook, but what does the ebook means? Is it just subscribing from you? Or there is specific ebook you made before? If it is, can you let me know how I can download yours?
I’ll come by here frequently and ask you a lot things
Thank you in advance!~
@ysn: Its a pdf. I emailed you the details on how to download
Thank you Mr.Krishna
I’m new student in telecommunication field. I have so many question that make me confuse. I hope you can give me an explanation the difference of transmitting symbol between OFDM and SC. For ex. if we have 2 ofdm symbol how i can make these symbols through to the channel??? we convolve each of ofdm symbol with different channel coefficient (time varying) or we convolve 2 ofdm symbols directly with channel coefficient. And if we have 4 BPSK symbols how i make these symbols through to the channel??? I want to compare between SC and OFDM system. Please help me to solve my problem.
Thanks
@Newbie: Well, there are no defined answers to your questions. In general, the channel can be modeled as an FIR filter and the idea is to convolve the time domain tx samples with channel taps. Channel taps can be time varying or static depending on the channel which you wish to simulate.
Thank you Mr. Krishna for ur explanation. I will try to ask other question later about OFDM and frequency selective fading channel because i don’t understand yet.
Regards
@Newbie: Ok
hi, krishna , i’m already a member of dsp lo, But i don’t know how can i download the book, can u plz send me the instructions
@Romeo: I emailed you the instructions
How do i download your free ebook?
@suma: I emailed you the instructions….
Dear Krishna,
Can you please tell me where can I download a softcopy of Digital Communication: Third Edition, by John R. Barry, Edward A. Lee, David G. Messerschmitt. I need the chapters that talks about the BER calculation of MMSE and SIC. Please help
@Pavel: The book should be available in most stores. And there is also an eastern economy edition ….
Can u please tel me how to e-mail your free ebook. Can u please email me the instructions?
@nowfel: I emailed you the download instrctions
@nowfel: I emailed you the download instructions
hello sir,
sir plz….reply fast
Hi,
How can i download free book?
@adisorn: I emailed you the download instructions
Hi Krishna,
Is it possible to have details to download the ebook? Thank you very much for the blog very helpful
Thanks,
@miline: I emailed you the download instructions.
Hi Krishna,
I would like to know how can I get octave installation with package for signal.
I haveinstalled v3.2.0 octave but without signal package and while trying to install signal package from octave I have to face a series of errors and still not fully succeeded in resolving all.
Though octave community is helping me, I would like to know how did you install octave with relevant packages for communication and signal processing ?
Thanks in advance
Bijoy
@bijoy: I have ubuntu. So, I just did sudo apt-get install ubuntu. For the additional packages, I think I downloaded the zip and kept the folder in the octave path
Good luck.
I am a subscriber but i didn’t find where to download the e-book.
@elka: I emailed you the instructions
dear krishna,
i am new to communication field.
i m need of simulating Bpsk and QPSK modulation schemes adding AWGN and its transmission in reyleigh fading channel to analyse the BER performance for differnt SNR values.
the carrier frequency haas to be 20 MHZ.
i am running out of time.
i would be useful if u could provide me with the matlab codes for dis.
pls do respond as soon as possible.
regards,
jansi
@jansi: The following posts might be of help
a) BPSK in AWGN : http://www.dsplog.com/2007/08/05/bit-error-probability-for-bpsk-modulation/
b) BPSK with OFDM in AWGN : http://www.dsplog.com/2008/06/10/ofdm-bpsk-bit-error/
c) QPSK in AWGN : http://www.dsplog.com/2007/11/06/symbol-error-rate-for-4-qam/
hai, i am already a member and how can i download the ebook
@venkat: I emailed you the instructions
Hi Krishna,
Sorry but I didn’t receive your instruction sent to me on 3th june. Is it possible to resend to me?
Thanks a lot ,
@miline: I emailed the details again.
Dear Krishna,
Can you mailed the instruction.
BR,
@andjas: I emailed you the details.
how can i download the ebook’ ebook on error probability in AWGN’ . i m already subscribed at dsplog.com
@Rajesh: emailed you the instructions
Hi Krishna!
Please, help me to download your ebook.
Thanks!
@Alex:
Have you subscribed to email newsletter from dsplog.com.
If not, please click here to subscribe.
http://www.feedburner.com/fb/a/emailverifySubmit?feedId=1348583&loc=en_US
Once you have subscribed, you should have received a confirmation email. Please reply to that
email and you will receive email instructions on how to download the eBook.
Hi dear
Thanks for your helpful blog ..
how to get an access to the e-book on probability of error in AWGN.
@Entisar:
Have you subscribed to email newsletter from dsplog.com.
If not, please click here to subscribe.
http://www.feedburner.com/fb/a/emailverifySubmit?feedId=1348583&loc=en_US
Once you have subscribed, you should have received a confirmation email. Please reply to that
email and you will receive email instructions on how to download the eBook.
Can you mailed the instruction.
I just subscribe to your blog/site. How can I download the e-book?
@Willie: Emailed you the download instructions
Hi Krishna,
Could you please tell how to download the book?
Thanks
@Mahi: Have you subscribed to email newsletter from dsplog.com.
If not, please click here to subscribe.
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Once you have subscribed, you should have received a confirmation email. Please reply to that
email and you will receive email instructions on how to download the eBook.
Dear Krishna,
How i can download free ebook.please sent me i am badly needed this book , because i have to submit my thesis paper on 30 may2011.
@moyeen: Have you subscribed to email newsletter from dsplog.com.
If not, please click here to subscribe.
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Once you have subscribed, you should have received a confirmation email. Please reply to that
email and you will receive email instructions on how to download the eBook.
Excelent posts and exemples. Congratulations Krishna!
Can you please e-mail me the e-book.
Thanks
Ivan – Brazil
I just subscribe to your site. How can I download the e-book?
@ayush: emailed you the instructions
hello,
i am working on DVB-H Tx and Rx design. i want to about hierarchical modulation development in DVB-H..how the mapping is done? how to write MATLAB code for the same. help me..
@SHWETA: Sorry, have not studied the DVB-H spec.
hello Mr Krishna
My name is Lemonia Tamvaki and I am a new user of Matlab. I try to understand the script for computing BER with Binary Convolutional Code and Viterbi decoding that I find in address
http://www.dsplog.com/db-install/wp-content/uploads/2009/01/script_bpsk_ber_awgn_convlutional_code_soft_viterbi_decode.m
But when I try to run the code there are some errors.
??? Error using ==> conv2
First and second arguments must be single or double.
Error in ==> conv at 40
c = conv2(a(:),b(:),shape);
Error in ==> theod5 at 37
cip1 = mod(conv(ip,[1 1 1 ]),2);
I am a new user of Matlab. I try to fix it by myself but it isn’t work.
Can you help me please?
Thank you
Lemonia Tambaki
@Lemonia: Not sure why you are seeing this error. I tried in Octave ver 3.0.5 and it went through.
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