## Q: Codedec for Lost Packet Recovery

Started by in comp.dsp16 years ago 5 replies

Hi guys, the following setting: - we send data packets of exactly b bytes, e.g. b=1000 - if a data packet is received then it's always...

Hi guys, the following setting: - we send data packets of exactly b bytes, e.g. b=1000 - if a data packet is received then it's always error free - but, sometimes packets are lost, let's say t is the lost packet rate - it is not possible to ask the server to send a packet again Which type of codec should be used to recover the lost packets? Is a reed-solomon with interleaver the best ...

## Can reed-solomon code applied in CCSDS be decoded through Berlekamp-Massey algorithm？

Started by in comp.dsp14 years ago 6 replies

In CCSDS,RS(255,223)code,the roots of the generator polynomial are not consecutive,which follows as ...

In CCSDS,RS(255,223)code,the roots of the generator polynomial are not consecutive,which follows as G(x)=(x-a^(11*112))*(x-a^(11*113))...*(x-a^(11*143)) I applied a kind of modified Berlekamp-Massy algorithm to resolve key equation S(x)*delta(x)=omega(x)(mod x^d) (s(x)=s0+s1*x+...+sd*x^d, d is minimum code distance,delta(x) is error location polynomial and o...

## Reed-Solomon Error Locator Roots

Started by in comp.dsp12 years ago 1 reply

I've got a RS implementation that's producing correct error values for a (204,188) code with generator g(x) =...

I've got a RS implementation that's producing correct error values for a (204,188) code with generator g(x) = (1-a^0x)(1-ax)...(1-a^(2t-1)x) The thing that has me puzzled is that I'm producing the correct error values, but when I go to look at the roots of the error locator, they don't seem to be correct. Example: I placed errors in samples 0-3 of the received codeword, so I would expect to ...

## reconstructing image

Started by in comp.dsp12 years ago 8 replies

I have image 256*256 , i compressed it using the Block Processing 'block' to be 128*128, and i want to encode it by reed solomon . so i export...

I have image 256*256 , i compressed it using the Block Processing 'block' to be 128*128, and i want to encode it by reed solomon . so i export it to the workspace using yout block and encode it by rsenc as follows: p=gf(yout,8) code=rsenc(p,138,128) d=rsdec(code,138,128) and this works fine but i want now to reconstruct the image after it had been decoded as variables , d and code are o...

## Reed Solomon decoding for arbitrary primitive elements in GF(2^m)

Started by in comp.dsp15 years ago 1 reply

Hello I wish to know how to implement RS decoding for any arbitrary primitive element in GF(2^m). Most literature covers decoding assuming...

Hello I wish to know how to implement RS decoding for any arbitrary primitive element in GF(2^m). Most literature covers decoding assuming that the primitive element is of the form alpha^1. In the CCSDS standard, the RS(255,239) code employs a generator polynomial of the form: g(x)=(x-A^120)(x-A^121)...(x-A^135) where A=alpha^11 is a primitive element in GF(255) [other valid primit...

## Minimum weight of a cyclic code determined by the generator polynomial?

Started by in comp.dsp17 years ago 1 reply

Hi, For a binary cyclic code with a generator g(x), the minimum hamming distance of the code is determined by the weight of g(x). Is this...

Hi, For a binary cyclic code with a generator g(x), the minimum hamming distance of the code is determined by the weight of g(x). Is this also true for non-binary cyclic codes like Reed-Solomon? Your time, effort and suggestions will be much appreciated Jaco

## Maximum distance seperable codes?

Started by in comp.dsp17 years ago 1 reply

Hi, Reed-Solomon codes are well-known codes which are also maximum distance separable (MDS), i.e. the minimum amount of redundancy is needed...

Hi, Reed-Solomon codes are well-known codes which are also maximum distance separable (MDS), i.e. the minimum amount of redundancy is needed to correct errors ( => dmin = 2t+1, where t equals the amount of correctable errors). RS codewords have length n, where n equals 2^m - 1 and m defines the Galois field GF(2^m) in which the code polynomial is defined. Thus, the Galois Field have 2^

## reed muller

Started by in comp.dsp14 years ago 1 reply

Hi, Given a generator matrix G for a non systematic reed muller code ( first order under permutation ), how to compute the...

Hi, Given a generator matrix G for a non systematic reed muller code ( first order under permutation ), how to compute the syndrome matrix H ? G = [ 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1; 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1; 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0,...

## What is the stop condition for Decoding Reed Solomon Codes with s erasures and v errors when s+2v>d using Euclid's Algorithm?

Started by in comp.dsp15 years ago 4 replies

Hi, I am trying to simulate a RS decoder using Euclid's Algorithm. I have one question about the stop condition. If there are s...

Hi, I am trying to simulate a RS decoder using Euclid's Algorithm. I have one question about the stop condition. If there are s erasures and v errors satisfying s+2v> d, what is the stop condition for Euclid's Algorithm. Thanks in advance. Have a nice day. Dayu Huang

## Reed-Solomon: generator matrix and generator polynomial approaches?

Started by in comp.dsp15 years ago 2 replies

Hi, Where can I find a proof in literature (or maybe someone can show me) why the following two approaches generate the same (n,k) RS...

Hi, Where can I find a proof in literature (or maybe someone can show me) why the following two approaches generate the same (n,k) RS code? The one approach is to generate the (n,k) RS code by the generator matrix: 1 1 1 ... 1 1 \alpha^1 \alpha^2 ... \alpha^{n-2} 1 \alpha^2 (\alpha^2)^2 ... (\alpha^2)^{n-2} G = . ...

## Coset leader of a coset code of RS codes

Started by in comp.dsp15 years ago 2 replies

Hi, I need some help on a problem regarding coset codes of Reed-Solomon codes (using GF(2^m)). I will quickly describe the...

Hi, I need some help on a problem regarding coset codes of Reed-Solomon codes (using GF(2^m)). I will quickly describe the problem. Define the same_symbol_weight of a codeword c as the maximum number of same symbols contained in c. Define the same_symbol_weight of a codebook C as the number of same symbols of c_s, where c_s is a codeword in C containing the maximum number of same ...

## First and second order reed muller code words

Started by in comp.dsp15 years ago 2 replies

Hi, I am looking for first and second order reed muller code words of length 31 (do they exist?). I have had a quick look on Google, but...

Hi, I am looking for first and second order reed muller code words of length 31 (do they exist?). I have had a quick look on Google, but most of the articles are on decoding strategies without actually listing the code words. Would any of you know where these codes are tabulated? I couldnt find them in Proakis or other Comms texts, either. (In case you are wondering, I am working through...

## (32,10) 2nd order reed muller code generation

Started by in comp.dsp14 years ago 1 reply

Hi, Can some one please tell me how (32,10) subcode of 2nd order reed muller code is derived. I need to understand the coding theory behind...

Hi, Can some one please tell me how (32,10) subcode of 2nd order reed muller code is derived. I need to understand the coding theory behind this code as its used in Layer 1 UMTS 3GPP 25.212 specification to encode TFCI. What are its special properties and why this code was choosen for TFCI encoding. It would be of great help if someone can give me technical papers published on the same. Rega...

## Binary self dual codes, first order Reed Muller codes

Started by in comp.dsp14 years ago 1 reply

Hello. I've been trying to learn more about special linear codes such as Reed-Muller codes, binary self-dual and self-orthogonal codes,...

Hello. I've been trying to learn more about special linear codes such as Reed-Muller codes, binary self-dual and self-orthogonal codes, and stumbled upon a couple of problems. For example, is there a binary self-dual (10,5,4) code? In some articles I've read, it was 'shown' that it does exist, but my colleagues say it does not. So I am rather confused as to who to believe. Now just for a ...

## Re: Undersampling of a clean carrier

Started by in comp.dsp15 years ago 2 replies

"Paul Solomon" wrote in message news:431e07ae$1@dnews.tpgi.com.au... > > "Thomas Magma" wrote in message > ... "Paul Solomon" wrote in message news:431e07ae$1@dnews.tpgi.com.au... > > "Thomas Magma" wrote in message > news:dXiTe.402841\$5V4.32336@pd7tw3no... > > > > "Paul Solomon" wrote in message > > news:4316590d@dnews.tpgi.com.au... > > > Hi, > > > > > > I have just been doing some test and I noticed a concerning problem that

## Re: I and Q SNR in a IQ mixer

Started by in comp.dsp15 years ago 10 replies

"Paul Solomon" wrote in message news:34f9711612698c7acf27766fed0@news.tpg.com.au... > > Hi, > > This should be a quick one...

"Paul Solomon" wrote in message news:34f9711612698c7acf27766fed0@news.tpg.com.au... > > Hi, > > This should be a quick one (hopefully), I have been doing some exploritory > surgery with signal tap and matlab on the FM demod I am working on and I > have noticed that I and Q channels have different SNR, one might have 30dB > the other 50dB. Is this normal, or woul

## Re: Demod Woes

Started by in comp.dsp15 years ago 8 replies

I have used the I,Q,dI,dQ equation below in a high-performance FM receiver. It worked really well. See questions below. Dirk Paul Solomon...

I have used the I,Q,dI,dQ equation below in a high-performance FM receiver. It worked really well. See questions below. Dirk Paul Solomon wrote: > Hi All, > > This email is partly an update and thanks for past help, and partly a plea > for further help. > > Thanks for your replies from my previous thread on my demod issues, I have > had someone send me some fir coeff's for the diffe

## Need help on meaning of these terminology of reed-muller code.

Started by in comp.dsp13 years ago 4 replies

Hi, I want to know meaning of the word below: - "Self dual" , What's for? - "Dual code" ,What's for? - "Soft decision" ...

Hi, I want to know meaning of the word below: - "Self dual" , What's for? - "Dual code" ,What's for? - "Soft decision" ,What's for? and what's about algebraic code ? what's about equivalent relation in the coding theory? Thamk for your help, Phongphan porana. phongphanp@yahoo.com

## Reed Muller error correction

Started by in comp.dsp13 years ago

i have tried to understand it, but somehow didn't succeed.... can anybody tell me if the following code can be a private case of this code: say...

i have tried to understand it, but somehow didn't succeed.... can anybody tell me if the following code can be a private case of this code: say there are (2^m-m-1)*(2^n-n-1) information bits, we form them in a matrix, and for each row of the matrix (contains 2^m-m-1 bits) calculate m bits such that if you insert the whole row in a LFSR, you'll have all zeros in the register. do the same fo...

## Channel performance of OFDM over an AWGN......

Started by in comp.dsp12 years ago 4 replies

hi all! i am going to simulate (myself for understanding more, not using Matlab toolbox) wireless channel by M-QAM over an AWGN, so that I've...

hi all! i am going to simulate (myself for understanding more, not using Matlab toolbox) wireless channel by M-QAM over an AWGN, so that I've to choose one of the FEC coding method such as Rayleigh, LDPC, turbo, Red-Solomon or BCH. which is the better one? and is it possible to use AWGN with Rayleigh at the time? if it is possible please explain me how to make a algorithm for it. and pleas...