## Forums Search for: Reed Solomon

## Reed Solomon encoding- please clarify

inHello, I am not sure if my previous message got posted successfully, so here I am sending the message associated with Reed-Solomon encoding...

Hello, I am not sure if my previous message got posted successfully, so here I am sending the message associated with Reed-Solomon encoding once again. I am testing my RS encoder/decoder that I built using LabVIEW. I had a few questions to ask to this knowledeable audience... Here they are: When converting bits to RS symbols in GF(n+1)for a RS(n,k)code for commercial standards like DVB, C...

## Q on Reed-Solomon Uncorrectable Errors

inHello! I have a Reed-Solomon design which is a shortened (15,11) code (to (12,8). I am nowhere near done running test patterns through it...

Hello! I have a Reed-Solomon design which is a shortened (15,11) code (to (12,8). I am nowhere near done running test patterns through it yet, but it does seem to be correcting the 1 and 2 error cases properly. However I was expecting it to be able to reliably detect the three-error cases and indicate uncorrectability. Instead I have some three-error vectors which are not detected a...

## Reed Solomon encoding

inHere I post the same message I've posted in another forum, where I've not yet received an answer. I've a basic question about encoding with...

Here I post the same message I've posted in another forum, where I've not yet received an answer. I've a basic question about encoding with Reed Solomon code. Suppose that C is a RS-code of length n = q-1 over the field F_q, designed distance d and dimension k. Let b a primitive element in F_q. The generator of the code is g(x) = (x-b) (x-b^2)...(x-b^(d-1)). Now, if I want to encode an el...

## A Reed-Solomon Decoder Question

inHi Guys, I am hoping someone in this group would be able to answer this question. I am working on a Reed-Solomon decoder for WiMAX 802.16-2004....

Hi Guys, I am hoping someone in this group would be able to answer this question. I am working on a Reed-Solomon decoder for WiMAX 802.16-2004. Its a RS(255,239,T=8) code. The generator polynomial is g(x) = (x + a^0)(x + a^1)(x + a^2) ...(x + a^(2T-1)) You'll notice that the first root of g(x) is 1. I have run into a problem when I use this g(x). It seems the error evaluator polynomial ...

## Reed Solomon for packet lost recoverage (erasures)

Hi! I'm working on FEC schemes in order to apply them in a real-time application. After reading a lot of stuff, I considered Reed Solomon...

Hi! I'm working on FEC schemes in order to apply them in a real-time application. After reading a lot of stuff, I considered Reed Solomon (n,k) as one of the algorithms to use, so I decided to program it in C programming language. The main concern for me are ERASURES (lost packets in the network), but not errors. As I understand, with a RS(n,k): 2*t = n - k v + e/2

## Reed solomon-error correction

inHi all, What does the reed solomon decoder outputs in the case when we have more than "t" errors to correct? Does he correct some errors and...

Hi all, What does the reed solomon decoder outputs in the case when we have more than "t" errors to correct? Does he correct some errors and leave other errors as they came, or he will correct any thing (i.e the data that was in the input will appear in the output)? Thanks in advance!

## Reed-Solomon detecting capacity in practise

inHi, I have implemented a Reed-Solomon coder/decoder (14,10) with symbols over GF(2^4) and I am having some problems with it's error detecting...

Hi, I have implemented a Reed-Solomon coder/decoder (14,10) with symbols over GF(2^4) and I am having some problems with it's error detecting capacity. As far as I know such code can correct up to t=(n-k)/2 errors, and according to a book "Essentials of Error-Control Coding" by J.C.Moreira, it's minimum Hamming distance dmin=t2+1 (t2=n-k). It is said there too that when there is less than dm...

## Reed-Solomon example in 802.16 standard

inHi-- I'm having difficulty getting the same results as the Reed-Solomon encoded test vectors provided in the 802.16 standard. The systematic...

Hi-- I'm having difficulty getting the same results as the Reed-Solomon encoded test vectors provided in the 802.16 standard. The systematic part is fine, the problem is with the parity bits. I'm using Matlab to simulate the RS encoding (using rsenc). Anybody has had a similar problem? Any Matlab source code available to generate the "right" codewords? Thanks for your help! This m...

## Reed-Solomon FEC necessary to have the same characteristic for symbols and words?

inHi there, I have implemented an almost "universal" (read: compatible with most other decoders output) Reed-Solomon codec. I feel like I have a...

Hi there, I have implemented an almost "universal" (read: compatible with most other decoders output) Reed-Solomon codec. I feel like I have a good intuitive grasp on the whole codec, except for one thing: I just can't understand why we are tied to the same characteristic at both the symbol level and at the word level. Let me explain: if for example you choose to work on GF(2^8), this means ...

## Practical differences between BCH and Reed-Solomon codes?

inSo I've got a Reed-Solomon codec that will work for a range of code parameters, and I'm looking to extend it (or at least use it as a...

So I've got a Reed-Solomon codec that will work for a range of code parameters, and I'm looking to extend it (or at least use it as a starting point) for a binary BCH decoder that is similarly flexible. I thought I'd bounce my understanding of the practical differences between BCH and RS codes off of comp.dsp to see if I'm missing any important points. Primary Difference 1: To calculate the...

## RTCA's reed-solomon logic or illogic.....

inHi, According to the RTCA's VDL mode specifications for reed-solomon (which btw is the same as the CCSDS), for messages less than NN (code...

Hi, According to the RTCA's VDL mode specifications for reed-solomon (which btw is the same as the CCSDS), for messages less than NN (code length) padding of 0 bytes has to be appiled. The padding is not transmitted, however at the reciever it is reapplied, my question is that along with the padding not being transmitted so to are FEC symbols not being transmitted. according ...

## Newton's identitires and reed solomon decoding

inHi!!! I am currently working on a Reed Solomon Codec. My team as finished working on the encoder section and it works like a charm thanks to...

Hi!!! I am currently working on a Reed Solomon Codec. My team as finished working on the encoder section and it works like a charm thanks to all the people on google Groups. I have started studding how the decoder works from ?Error Control systems for Digital communication & storage' by Stephen B. Wicker. We are currently studding the following decoders 1. Peterson ? Gorenstein ? Zierler D...

## forward error correction capabilities?

inHello I wanted to know the difference that can exist between(among) a flow of bits that goes out of a decodificador viterbi + Reed solomon and...

Hello I wanted to know the difference that can exist between(among) a flow of bits that goes out of a decodificador viterbi + Reed solomon and the flow of bits originally in a transmission of tdt cofdm That is to say: do I obtain the same result to the exit of the corrector Reed Solomon with a BER before Viterbi of 9-6 that with a BER before Viterbi of 2-2? Said otherwise: Do I obtain...

## BCH Codes and Reed-Solomon Codes

inDoes any one know of any research which attempts to analytically determine the the binary codeword subspace (BCH code) of a Reed-Solomon code,...

Does any one know of any research which attempts to analytically determine the the binary codeword subspace (BCH code) of a Reed-Solomon code, that is the binary vector subspace of a subspace of GF(2^m - 1)^n? -- % Randy Yates % "My Shangri-la has gone away, fading like %% Fuquay-Varina, NC % the Beatles on 'Hey Jude'" %%% 919-577-9882 % %%%...

## Erasure Decoding using Reed Solomon Codec

inHi!!! Can somebody Please provide me with a reliable source for studding and implementing a Reed Solomon Decoder capable of correcting...

Hi!!! Can somebody Please provide me with a reliable source for studding and implementing a Reed Solomon Decoder capable of correcting Erasures? I have already implemented the syndrome detector, the Erasure Polynomial, Berlekamp ? Massey Algorithm and the program (written in C using VC++) is capable of finding the correct error / erasure locator polynomial but for some reason the (Modifi...

## Reed-Solomon Coding under ITU-J.83 Annex-B

Hiiiii, I am Jitendra,Comm.Engg. making Reed-Solomon Codec using specs of ITU-J.83 Annex-B. Specs are : n=128,k=122, under...

Hiiiii, I am Jitendra,Comm.Engg. making Reed-Solomon Codec using specs of ITU-J.83 Annex-B. Specs are : n=128,k=122, under GF(128), 7-bit symbol, Generator Polynomial : G(x)=(x+alpha^1)(x+alpha^2)(x+alpha^3)(x+alpha^4)(x+alpha^5); As per the standard I come up with a encoder, But I didnt have any reference to verify/check my codeword. In matlab, RS functions are taking n and k ...

## soft decision decoding of Reed-Solomon

inHi, I work out a method soft decision decoding of Reed-Solomon codes. Somebody is known on this method or has some information on this...

Hi, I work out a method soft decision decoding of Reed-Solomon codes. Somebody is known on this method or has some information on this theme? I will very grateful for every help. Regards. Wojtek Lach

## Reed Solomon code in C required

inHello all, I am Amit Gupta, I have implemented Reed Solomon decoder RS(255,191) in Verilog, But to make confirm that i have...

Hello all, I am Amit Gupta, I have implemented Reed Solomon decoder RS(255,191) in Verilog, But to make confirm that i have implemented all the block correct I need C code, Because i have not implemented all the blocks till now, they are in progress. But to know which block is giving Error result I need C code to verify. I have implemented Reformulated Inversionless Berlekamp-Massey a...

## Reed Solomon decoder -help

inThis is the first time Ive implemented a Reed Solomon decoder, and Im having some strange problems , which I have not been able to debug. Ive...

This is the first time Ive implemented a Reed Solomon decoder, and Im having some strange problems , which I have not been able to debug. Ive implemented a RS(255,191) code. That makes it a lil hard to verify all steps of my C code by calculations on paper. Anyways, Ive tried Euclids and Berlekamp in C, I always get the correct error locations, but my magnitudes are not correct. If my Error l...

## Need help decoding shortened Reed-Solomon (24,12,13) using c++

inHello, I am working on an academic project. I need to do Reed-Solomon decoding on data payload bits encoded with the shortened (24,12,13) RS...

Hello, I am working on an academic project. I need to do Reed-Solomon decoding on data payload bits encoded with the shortened (24,12,13) RS code over GF(2^6). I prefer Simon Rockliff's rs.c code because of its relative simplicity. However, I am having two problems. (1) I need to make the code handle the shortened code which is shortened by deleting the 39 left most info symbols; And (2) an...