On 2007-02-09, kittuis4u <kittuis4u@gmail.com> wrote:

>
> I am using n=31 and k=29. This means that it has to correct 2 symbols(5
> bits each). I would like to know few things about the error correction
> codes.

Are you confusing errors and erasures?
--
Ben Jackson AD7GD
<ben@ben.com>
http://www.ben.com/

Reply by Vladimir Vassilevsky●February 9, 20072007-02-09

kittuis4u wrote:

> I also tried to implement a cyclic code with very high values of (n,k).
> When I tried that and check if the code is able to correct all the 2 bit
> errors, it was not able to do that. The minimum distance for the code is 6
> but it was not able to correct all the 2 bit errors. Could you let me know
> why this is happening. the (n,k)=(117,102) in my code.

You should do your homework yourself.
VLV

>
>

Reply by kittuis4u●February 9, 20072007-02-09

>
>
>kittuis4u wrote:
>
>> Hi I am Krishna Chaitanya. I am trying to implement reed-solomon codes

and

>> check what is the performance of the coding scheme.
>> I am using n=31 and k=29. This means that it has to correct 2

symbols(5

>> bits each).
>
>????
>(31,29) is a Hamming code in GF(2^5). It can correct for one symbol

only.

>
>
> I would like to know few things about the error correction
>> codes.
>
>R. Blahut "The theory and practice of the error control codes"
>
>> When ever I induce more than 1 symbol error, that is lets say I

introduce

>> and error of 7 bits, now the error correction code has to correct the

1

>> symbol that it has to and then leave the remaining errors right?
>> But when I try to check this it not only gives all the 7 bits as error

but

>> some times it also increases the number of errors.
>>
>> Is there any specific reason for that. Please let me know about this.
>
>No wonder. If there are more errors then the particular code can
>correct, then the attempt to correct the errors can only make the things

>worse.

I also tried to implement a cyclic code with very high values of (n,k).
When I tried that and check if the code is able to correct all the 2 bit
errors, it was not able to do that. The minimum distance for the code is 6
but it was not able to correct all the 2 bit errors. Could you let me know
why this is happening. the (n,k)=(117,102) in my code.

Reply by Vladimir Vassilevsky●February 9, 20072007-02-09

kittuis4u wrote:

> Hi I am Krishna Chaitanya. I am trying to implement reed-solomon codes and
> check what is the performance of the coding scheme.
> I am using n=31 and k=29. This means that it has to correct 2 symbols(5
> bits each).

????
(31,29) is a Hamming code in GF(2^5). It can correct for one symbol only.
I would like to know few things about the error correction

> codes.

R. Blahut "The theory and practice of the error control codes"

> When ever I induce more than 1 symbol error, that is lets say I introduce
> and error of 7 bits, now the error correction code has to correct the 1
> symbol that it has to and then leave the remaining errors right?
> But when I try to check this it not only gives all the 7 bits as error but
> some times it also increases the number of errors.
>
> Is there any specific reason for that. Please let me know about this.

No wonder. If there are more errors then the particular code can
correct, then the attempt to correct the errors can only make the things
worse.
Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

Reply by kittuis4u●February 9, 20072007-02-09

Hi I am Krishna Chaitanya. I am trying to implement reed-solomon codes and
check what is the performance of the coding scheme.
I am using n=31 and k=29. This means that it has to correct 2 symbols(5
bits each). I would like to know few things about the error correction
codes.
When ever I induce more than 1 symbol error, that is lets say I introduce
and error of 7 bits, now the error correction code has to correct the 1
symbol that it has to and then leave the remaining errors right?
But when I try to check this it not only gives all the 7 bits as error but
some times it also increases the number of errors.
Is there any specific reason for that. Please let me know about this.
Thanks and Regards,
Krishna Chaitanya.