## Soft decision decoderReed Solomon implementation

Started by in comp.dsp15 years ago 5 replies

Hi, Is anyone out there aware of any implementations (C/MATLAB) of Soft Decision Decoding for Reed Solomon, that I could use for research...

Hi, Is anyone out there aware of any implementations (C/MATLAB) of Soft Decision Decoding for Reed Solomon, that I could use for research work? Thanks alot RS.

## Question about Reed Solomon decoder for 802.16

Started by in comp.dsp15 years ago 2 replies

Hi, I have a question about decoding Reed Solomon code used in 802.16 standard. In the 802.16-2004 document, RS(255,239,8) is used, but...

Hi, I have a question about decoding Reed Solomon code used in 802.16 standard. In the 802.16-2004 document, RS(255,239,8) is used, but the output is usually punctured to produce shorter codeword, RS(40,36,2) for example. The question is: because the parity bytes is reduce from 16 bytes to 4 (first) bytes, how we design the decoder? Padding zero bytes to the parity and data to form RS(255,239,8) ...

## Reed Solomon with Erasure

Started by in comp.dsp13 years ago

I have a question about key eqation solver when supporting erasure in reed solomon B(x) = erasure locator polynomial S(x) = syndrom...

I have a question about key eqation solver when supporting erasure in reed solomon B(x) = erasure locator polynomial S(x) = syndrom polynomial ELP(x) = error locator plonomial Z(x) = value polynomial key equation solver is : ELP(x). B(x). S(x) = Z(x) mod X^2t if T(x) = B(x). S(x)] mode 2t => key equation slover: ELP(x) . T (x) = Z(x) when I implement normal Berlekamp (2t iter

## 802.16-2004 Reed-Solomon test vectors and parity position

Started by in comp.dsp14 years ago

Using the test vector and Reed-Solomon encoding parameters defined in IEEE Std 802.16-2004, my MATLAB code returns the required test vector...

Using the test vector and Reed-Solomon encoding parameters defined in IEEE Std 802.16-2004, my MATLAB code returns the required test vector with extra bytes. My MATLAB code (shown below) is based on an earlier thread in this group. The problem is that the output vector is longer than expected even after removing the zero padding and that the parity bytes are in the wrong position. Has anyone exper...

## Doubt

Started by in comp.dsp13 years ago 5 replies

Hi All I would be very thankful if you could verify the result that I have got. System-1: BPSK, AWGN, Reed Solomon Code (255,127) i.e. rate...

Hi All I would be very thankful if you could verify the result that I have got. System-1: BPSK, AWGN, Reed Solomon Code (255,127) i.e. rate 0.5 Result: At 0 dB the BER is 0.17 and at 5.5 dB BER is 0.003 System-2: BPSK, AWGN, Reed Solomon Code (255,239) 1.e. rate 0.93 Result: At 0 dB the BER is 0.09 and at 5.5 dB BER is 0.006 Can I assume that in System-1, after 5.5 dB the BER is 0 wh...

## Reed-Solomon decoding: Euclidean vs Massey-Berlekamp

Started by in comp.dsp14 years ago 1 reply

Hi There, Is there a difference between the two algoririthms regarding performance? Do both the algorithms correct all correctable...

Hi There, Is there a difference between the two algoririthms regarding performance? Do both the algorithms correct all correctable errors and erasures (d_{min} > = 2s + e, s - errors, e - erasures)? When would one use the one algorithm instead of the other? Kind Regards, Jaco

## Reed-Solomon: inverting a matrix of GF elements

Started by in comp.dsp13 years ago 3 replies

How does one invert a matrix of GF elements? Specifically, I would like to see the case of a 3x3 matrix. Thank you for any information.

How does one invert a matrix of GF elements? Specifically, I would like to see the case of a 3x3 matrix. Thank you for any information.

## how to code over 63 symbols?

Started by in comp.dsp11 years ago 3 replies

Hi or 35, or pq symbols in general where p and q are relative prime so that both GF(p) and GF(q) exist? What I am asking about is if there is...

Hi or 35, or pq symbols in general where p and q are relative prime so that both GF(p) and GF(q) exist? What I am asking about is if there is some sort of nontrivial "product" code that would let us combine say a Reed-Solomon or BCH code over GF(p) and another over GF(q)? What I mean by trivial is this:let us say that we use 35-ary orthogonal modulation, say FSK; there is no G

## Theoretical BER

Started by in comp.dsp15 years ago 2 replies

Hi guys, I need to fing plots (or equations) for the theoretical BER for some error correction codes: Reed-Solomon, Turbo Codes, Viterbi,...

Hi guys, I need to fing plots (or equations) for the theoretical BER for some error correction codes: Reed-Solomon, Turbo Codes, Viterbi, CRC-8. Could someone please point me out where can I find this. Michael B.

## Shortening BCH codes?

Started by in comp.dsp12 years ago 3 replies

Quick question I'm sure someone can put to bed easily: Is it possible to shorten BCH codes in the same way that you shorten Reed-Solomon? ...

Quick question I'm sure someone can put to bed easily: Is it possible to shorten BCH codes in the same way that you shorten Reed-Solomon? My instinct is yes, but I want to make sure it's not going to do anything evil like reduce the minimum distance...

## How to using the Reed-Solomon decoder for the polynomial reconstruction

Started by in comp.dsp18 years ago 1 reply

Hi, I am dealing with a noisy polynomial reconstruction problem. I read some material saying that the error correct RS decoder can be use in...

Hi, I am dealing with a noisy polynomial reconstruction problem. I read some material saying that the error correct RS decoder can be use in this case. But I can not figure out the relationship between these two. Can anybody explain a little for me. Thanks in advance. Shenglin

Started by in comp.dsp9 years ago 13 replies

Hi all, just out of curiosity, I was digging into the RS codes, mainly for RAID-6 purposes. So, I was wondering about the possibility of...

Hi all, just out of curiosity, I was digging into the RS codes, mainly for RAID-6 purposes. So, I was wondering about the possibility of increasing the parity of such RAIDs. Looking around a found a document describing a 3 parity disks RAID, possible name RAID-7, if you want. The description there seems quite specific, i.e. it does describe 3 parities, but it seems to hint that a f...

## Generator polynomial for reed solomon codes

Started by in comp.dsp17 years ago 2 replies

Can anyone tell me which generator polynomial to use for rs(255,223) code and also how to find out generator polynomila for other rs...

Can anyone tell me which generator polynomial to use for rs(255,223) code and also how to find out generator polynomila for other rs codes...(n,k) sudeep

## BER in matlab

Started by in comp.dsp13 years ago 7 replies

Hi, I am trying to simulate a Reed-Solomon simulation over AWGN channel. When I plot the BER vs SNR the line stops every time in SNR 7db with...

Hi, I am trying to simulate a Reed-Solomon simulation over AWGN channel. When I plot the BER vs SNR the line stops every time in SNR 7db with BER almost 5*10^-5. I want the BER to be smaller than 10^-6. I tried to run for more codewords (e.x 10000) but the line stopped again at 5*10^-5. Any suggestions? Thanks.

## Fast encoding of RS codes

Started by in comp.dsp14 years ago 1 reply

Hi! I am doing some research in Computer Security, and I want to implement Reed-Solomon codes to get outputs of some provable minimum...

Hi! I am doing some research in Computer Security, and I want to implement Reed-Solomon codes to get outputs of some provable minimum distance. I've researched on speed benchmarks and they always seem to include the decoding stage as well. Can you point me towards some references on fast encoding of RS codes. And this is for a CS application so I would like to try the general code (not ju...

## Reed Solomon Numerical Example Question

Started by in comp.dsp12 years ago 3 replies

Will someone please check out these numbers? (Suze Orman always says "Show Me the Money." so I am asking someone to "Show Me the Numbers." I...

Will someone please check out these numbers? (Suze Orman always says "Show Me the Money." so I am asking someone to "Show Me the Numbers." I would like someone to work the same example I am working to find the error magnitudes and to demonstrate how the error magnitudes in the textbook can be obtained via the direct solution of the matrix equation. I am referring to an example in the following ...

## Syndrome computation for Reed Solomon code words

Started by in comp.dsp15 years ago 1 reply

I am trying to understand and design an RS Decoder. Can anyone help me understand how the syndrome is computed and how does the syndrome...

I am trying to understand and design an RS Decoder. Can anyone help me understand how the syndrome is computed and how does the syndrome computation help in reducing the search to find the errors in the input code word?

## DVB-T

Started by in comp.dsp16 years ago 1 reply

Hi everybody, I have a question related to the OFDM frame structure in a DVT-T system. The standard specifies that the input MUX packet is...

Hi everybody, I have a question related to the OFDM frame structure in a DVT-T system. The standard specifies that the input MUX packet is composed of 188 bytes: 1 synchronization byte and 187 data bytes. Along the transmision chain, the bit stream undergoes some interleaving and coding (Reed-Solomon and Convolutional). My question is: should this stages be also applied to the synchronizatio...

## help needed with generator polynomials of R-S codes

Started by in comp.dsp16 years ago 1 reply

Hello, I have some doubts about how to use Reed-Solomon codes. I am using communications toolbox of matlab to write my code. However, I am not...

Hello, I have some doubts about how to use Reed-Solomon codes. I am using communications toolbox of matlab to write my code. However, I am not sure about the influence of using differents primitive polynomials when creating the galois field.I usually use the default primitive polynomial which is the minimal one. Could it be the best choice? As for generator polynomials, I know that the gener...

## Reed solomon generator polynomial

Started by in comp.dsp17 years ago 1 reply

hi all, I have a generator polynomial in the format G (X) =3D (X-=B5j )(X-=B5j+1)......(X-=B5j+2t-1), and, if j=3D1, how can i get the...

hi all, I have a generator polynomial in the format G (X) =3D (X-=B5j )(X-=B5j+1)......(X-=B5j+2t-1), and, if j=3D1, how can i get the equation in this format g (X) =3D gn-kXn-k +gn-k-1Xn-k-1 + ........ g2X2+g1X + g0.