## Forums Search for: Reed Solomon

## 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-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...

## 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 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...

## REED-SOLOMON for 802.16

inHi, I don't understand the specification 802.16, concerning FEC/Reed-Solomon. May be someone can guide me to an answer? I developped RS coder,...

Hi, I don't understand the specification 802.16, concerning FEC/Reed-Solomon. May be someone can guide me to an answer? I developped RS coder, decoder(255,239,8). It works fine. I have the same results with the specification example. "The first test vector refers to full bandwidth (16 subchannels) using QPSK and overall coding rate 3/4. The RS code you use is (40,36,2). According to the test v...

## 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 ...

## 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 ...

## 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...

## 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...

## 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...

## 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...

## 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...

## Reed Solomon code

inHello, I am new to Reed Solomon coding theory. Can anybody help me on the following issues: 1. How to compute Generator matrix for RS code ...

Hello, I am new to Reed Solomon coding theory. Can anybody help me on the following issues: 1. How to compute Generator matrix for RS code over binary field ? 2. What are the ways for decoding a received binary pattern (length n) to a RS code [say, k is given]? 3. How can a binary pattern be list decoded to RS codes[ is given] ? If you have implementation codes (speciall

## reed solomon: z transform vs fourier transform

inHi all, I would like to have your opignon, which transform is better : Z-transform or Fourier transform for implementation of reed...

Hi all, I would like to have your opignon, which transform is better : Z-transform or Fourier transform for implementation of reed solomon codec? if it will be implemented on a DSP processor, what would be the performance? will I get a high speed with Z- transform or Fourier transform ? Thanks

## Reed solomon with erasures

inHello, I'm interested in using RS- Reed solomon codes with erasures. I know the RS code can correct 2g+e=n-k, where g is erasure and e...

Hello, I'm interested in using RS- Reed solomon codes with erasures. I know the RS code can correct 2g+e=n-k, where g is erasure and e is error. My system can find the erasures with high probability. My question is, if the system can detect X erasures but 50% of them are correct. Meaning they were mistakenly detected as erasures. Will I earn something using decoder with erasure or usin...

## 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...

## Reed-Solomon code block size choice

inHi all, In designing a reed-solomon code, one has to choose the appropriate code size. If the constraint is computational complexity and delay, is...

Hi all, In designing a reed-solomon code, one has to choose the appropriate code size. If the constraint is computational complexity and delay, is it better to use a large block size, or use several numbers of small blocks? In other words, for RS(n,k), is it computationally more efficient to have n=255, or divide data into 17 blocks with each one has n=15? Here we assume other factors like error c...