Code covered by the BSD License  

Highlights from
Turbo Code

5.0

5.0 | 3 ratings Rate this file 70 Downloads (last 30 days) File Size: 6.02 KB File ID: #39423
image thumbnail

Turbo Code

by Yogesh K Soniwal

 

11 Dec 2012 (Updated 30 Jul 2013)

Turbo code performance over AWGN channel using RSC encoder & BCJR decoder for code [1,1+D+D^2/1+D^2]

| Watch this File

File Information
Description

Information bits are encoded using RSC (Recursive Systematic Convolution) encoder. Additive White Gaussian Noise is included at the receiver and the received bits are decoder using iterative BCJR decoder.

Required Products Communications System Toolbox
MATLAB release MATLAB 8.1 (R2013a)
Tags for This File  
Everyone's Tags
awgn(3), bcjr decoder, ber, communications, fec, forward error correction code, parity bits, rsc encoder(2), systematic code, turbo, turbo code(2)
Tags I've Applied
Add New Tags Please login to tag files.
Please login to add a comment or rating.
Comments and Ratings (25)
31 Jul 2013 vahid

hi tank u for ur code.the decoder depends on the snr but in reallity we dont know the snr how can we implement this code ?

03 Jul 2013 triet ho

why only has 3rd iteration? i saw picture has 4th iteration? can you update iteration higher? tks so much. can you send your updated code to my email: hobaominhtriet@gmail.com. tks you.

28 Jun 2013 Yogesh K Soniwal

You can refer to code provided on this link for 16-QAM
http://www.dsplog.com/2007/12/09/symbol-error-rate-for-16-qam/

25 Jun 2013 DUJIN KWON

If I want to modify your program by using 16qam modulation instead of BPSK can you help me with that?

13 Jun 2013 Yogesh K Soniwal

no..performance for QPSK and BPSK will be different

12 Jun 2013 mary

will the performance be better when using QPSK modulation?? or it will be the same as when using BPSK?

12 Jun 2013 mary

Do you have a matlab code of it ? Can you do it for me please?

12 Jun 2013 Yogesh K Soniwal

You have to transmit 2 bits for each symbol. And decode each of them individually. Refer to the QPSK simulation code.

11 Jun 2013 mary

If I want to modify your program by using QPSK modulation instead of BPSK can you help me with that?

11 Jun 2013 Yogesh K Soniwal

Yes, the modulation used is BPSK.

10 Jun 2013 mary

another question i have >> the modulating you are using is BPSK right???

10 Jun 2013 mary  
10 Jun 2013 mary

i mean can we make the first RSC encoder of rate 2/3 ?? so according to this the second encoder will also be of rate 2/3

09 Jun 2013 Yogesh K Soniwal

no..we are using the same bits permuted for the second RSC encoder, so we can't make this code rate 2/3.

09 Jun 2013 mary

So it means that to make it of rate 2/3 we should use two bits as an input to RSC encoders right? Is it possible with BCJR decoding?

09 Jun 2013 Yogesh K Soniwal

There are two encoders. Information bits are coded using convolution code for the first encoder and their permutation is coded using convolution code for the second encoder, but only one bit is used for second encoder. So RSC encoder is rate 1/3.

08 Jun 2013 mary

okay and what about the bit rate of the RSC encoders??

05 Jun 2013 mary

okay thank you

15 May 2013 Yogesh K Soniwal

Hi mary,
this is rate 1/3 code..

15 May 2013 mary

what is the bit rate of this encoder please??

05 May 2013 saikiran

Hi, In the code when we increase block length the performance of the code should be increased in ber wise. But it is not the case happening?

29 Apr 2013 mary

or it is of 8 states?

29 Apr 2013 mary

okay it ran thank you

well this code is of 4 states trellis could you make it of 8 states ??

28 Apr 2013 Yogesh K Soniwal

You have not downloaded 'parity_bit' function which is used by turbo.m . That's why this error is coming. Download all the other functions (alpha_1, beta_1,gamma_1, parity_bit, lappr) and then run turbo.m

28 Apr 2013 mary

hello
when i ran it using matlab 2012 an error occured
"Undefined function 'parity_bit' for input arguments of type
'double'." what do i do?

Updates
30 Jul 2013

Iterations increased for better performance

Contact us