## Reed Solomon code

Started by in comp.dsp10 years ago 1 reply

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 ...

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 code block size choice

Started by in comp.dsp14 years ago 6 replies

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...

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...

## Fair comparision: Reed Solomon code and convolutional code

Started by in comp.dsp12 years ago 13 replies

Hello People I want to compare Reed Solomon code [255,239] and rate 1/2 convolution code with constraint length 5, i.e. generator polynomials...

Hello People I want to compare Reed Solomon code [255,239] and rate 1/2 convolution code with constraint length 5, i.e. generator polynomials are [23 35]_8; Now, my channel is frequency selective, doppler effect and noise. Also the way I am scaling the noise is sigma=sqrt(0.5*Eb/(Rc*snr_lin)) where for RS, the Rc=239/255 and for convolution encoder Rc=1/2; Is this fair compari...

## Reed solomon with erasures

Started by in comp.dsp12 years ago 6 replies

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...

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...

## Question about Reed Solomon decoder for 802.16

Started by in comp.dsp14 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) ...

## Euclidean algorithm used to decode Reed-Solomon codes?

Started by in comp.dsp17 years ago 2 replies

Hi, Two traditional ways to decode Reed-Solomon codes include the Massey-Berlekamp and Euclidean decoding algorithms. Can someone please...

Hi, Two traditional ways to decode Reed-Solomon codes include the Massey-Berlekamp and Euclidean decoding algorithms. Can someone please explain the underlying theory on which the Euclidean algorithm is based, or perhaps give some pointers in literature where it is covered? Does it have anything to do with the Euclidean algorithm used in abstract algebra to compute the GCD? Your ti...

## Order of encoder output in Reed-Solomon encoding

Started by in comp.dsp15 years ago 1 reply

Hello: I had a query regarding the encoder transmission format order at the Reed-Solomon encoder output for the commercial standards such...

Hello: I had a query regarding the encoder transmission format order at the Reed-Solomon encoder output for the commercial standards such as European DVB, North American ATSC/ITU-J83 standards etc. For a RS (n,k) code, if the message polynomial is : m(x)=m(0)+m(1)*x+m(2)*x^2+......+m(k-1)*x^(k-1) and the parity polynomial is : c(x)=c(0)+c(1)*x+...........+c(n-k-1)*x^(n-k-1). Is the ree...

## reed solomon: z transform vs fourier transform

Started by in comp.dsp14 years ago 2 replies

Hi 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 decoder Berlekemp massey algorithm

Started by in comp.dsp15 years ago 1 reply

hey i am implementing reed solomon encoder decoder using verilog. I want to implement a decoder using berlekemp massey algorithm. I am looking for...

hey i am implementing reed solomon encoder decoder using verilog. I want to implement a decoder using berlekemp massey algorithm. I am looking for a hardware of that so that i can write a verilog code. any sort of help is highly appreciated. I am a student.

## Regarding Generator Matrices of MDS codes?

Started by in comp.dsp14 years ago 2 replies

Hi There, I am a bit confused. If I recall correctly, I have read/learned that any submatrix of a generator matrix is invertible. If one...

Hi There, I am a bit confused. If I recall correctly, I have read/learned that any submatrix of a generator matrix is invertible. If one considers the non-systematic Reed-Solomon code generated by a Vandermonde matrix, this is true. However, if one considers the "Reed-Solomon" code generated by [I | C], where I is a k X k identity matrix, and C is a (k X n-k) Cauchy matrix, not every ...

## Reed Solomon error correction question

Started by in comp.dsp12 years ago 15 replies

I am normally a speech/audio processing engineer, so this is somewhat out of my primary expertise area. I have recently implemented the Reed...

I am normally a speech/audio processing engineer, so this is somewhat out of my primary expertise area. I have recently implemented the Reed Solomon error correction algorithm and have gotten it to work for the following case: the roots of the generator polynomial are in positions 1 through 2t, where t is the number of errors. However, I implemented the case where the roots of the generator poly...

## Reed-Solomon error correction capacity

Started by in comp.dsp12 years ago 15 replies

Hi: I am a newbie on Reed-Solomon coding, and I was wondering what happens when the received message has more errors than the error...

Hi: I am a newbie on Reed-Solomon coding, and I was wondering what happens when the received message has more errors than the error correcting capacity 2t. I would say that the decoding fails completely, but I am not sure. Could anybody explain this to me?, is there anyway to prevent my decoding from crashing when the received message contains more than 2t errors? Thanks

## Reed Solomon with Erasure

Started by in comp.dsp12 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

## Erasures decoding of Reed Solomon codes

Started by in comp.dsp4 years ago 10 replies

Hi, I'm building an erasures decoder for Reed Solomon codes, and I'm having trouble when the number of erasures (without errors) exceeds...

Hi, I'm building an erasures decoder for Reed Solomon codes, and I'm having trouble when the number of erasures (without errors) exceeds (n-k)/2, the error-correcting capability of the code. When my code has no errors, and only erasures, I would expect the error locator polynomial to be uniquely 1. When I have up to (n-k)/2 erasures, that's exactly what happens. However, when the nu...

## Reed-Solomon encoder in Matlab

Started by in comp.dsp7 years ago 5 replies

Hi, I am trying to use the Reed-Solomon encoder in the Matlab Communications toolbox ( command rsenc). For example if you are trying to a...

Hi, I am trying to use the Reed-Solomon encoder in the Matlab Communications toolbox ( command rsenc). For example if you are trying to a (7,3) R-S encoder. When you use rsenc the inputs and outputs have are alphabets in the respective Galois fields ( GF(8) in this example). Is there a way to convert the input and output formats such that we can input a binary string and get a binary string o...

## Question about Reed-Solomon error control code

Started by in comp.dsp16 years ago 2 replies

Hi, I am simulating equalizer with Reed-Solomon channel code a frequency fading channel. The fading channel has a severe spectral null, I...

Hi, I am simulating equalizer with Reed-Solomon channel code a frequency fading channel. The fading channel has a severe spectral null, I use frequecy domain equalization to contre the null. At present I think the equalizer works well. When I add the RS(170,180) (8 bit) channel code for a data frame, I find the BER performance is not improved at all. It is even worse a little bit than that o...

## Reed solomon Berlekemp massey algorithm

Started by in comp.dsp15 years ago 1 reply

I am designing a reed solomon decoder encoder in verilog. while designing I was unable to calculate delta using Berlekmp massey algorithm. It...

I am designing a reed solomon decoder encoder in verilog. while designing I was unable to calculate delta using Berlekmp massey algorithm. It will be great help if you can give me some hint. delta(k) = syndrome(k) - sumation( lambda(k-1) * syndrome(k -i) lambda is something like zx^3+ ax2+ bx+1 syndrome is y by solving this suppose we get the delta = k. http://www.ee.ucla.edu/~ma...

## Reed Solomon Simulation

Started by in comp.dsp12 years ago 14 replies

Hi All I want to simulate Reed Solomon code with code rate 1/2 to compare rate 1/2 convolution code, I know that rate 1/2 RS will perform...

Hi All I want to simulate Reed Solomon code with code rate 1/2 to compare rate 1/2 convolution code, I know that rate 1/2 RS will perform better. So far I was using RS code of polynomial [255 239]; Can anybody please tell me how to simulate rate 1/2 code? Your help will be appreciated. Thanks Chintan

## Difficulty with article regarding decoding Reed-Solomon codes

Started by in comp.dsp4 years ago 2 replies

Hi, I am trying to implement the pseudocode given in the article "A new decoding algorithm for correcting both erasures and errors...

Hi, I am trying to implement the pseudocode given in the article "A new decoding algorithm for correcting both erasures and errors of Reed-Solomon codes" (appeared in IEEE Transactions on Communications, vol. 51, no. 3, March 2003). In section IV, the authors present an algorithm, (Algorithm 2), to decode both erasures and errors, using an algorithm based on the Euclidean algorithm toge...

## CCSDS Reed-solomon decoding- error evaluation

Started by in comp.dsp10 years ago

Hi, I'm making a CCSDS reed-solomon decoder. I'm using the C code as written by Simon Rockliff (1991) as a starting point. The main feature of...

Hi, I'm making a CCSDS reed-solomon decoder. I'm using the C code as written by Simon Rockliff (1991) as a starting point. The main feature of the CCSDS specification is that it uses alpha^11 as primitive element and generator polynomial roots are : alpha^(128-E) to alpha^(127+E), which makes the problem unusual. In the above C code, by changing the generator polynomial and using the roots of ...