Thread Subject: AWGN channel - Reed Solomon

Hi,
I am quite new to Matlab and I am trying to implement a AWGN
channel ,at the moment, for Reed-Solomon codes
My code is the following:

m=4;
k=9;
for SNRdB = 1: 1: 15;
data = randint(1,k,2^m-1);
message = gf(data,m);
enc = rsenc(message,2^m-1,k);
c=randn(1,2^m-1);
stdDev = 1/sqrt(2*10^(SNR/10));
noise = c*stdDev*sqrt(2^m-1/k);
cnoisy = enc + noise;
error = gf(cnoisy,m);
end

The problem I think is when the variable 'error ' is called
because is the 'noise' is an array but the 'cnoisy' is a
Galois field array, also an error occurs when the variable
'cnoisy' is called! (independently from the previous)
But I don't know how to make it work.
Thanks a lot.

Tikanis Mr. Apostolopoulous?

You can convert the variable "enc" from a Galois field data
type to a floating point data type like this:

   new_enc = enc.x;

Also, don't you want to insert a modulator in there?

   modulated_signal = some_modulator(new_enc);
   noisy_signal = modulated_signal + noise;

Good luck,
Matheos from USA

"magouliana Apostolopoulos" <helo@in.gr> wrote in message
<g4re96$svh$1@fred.mathworks.com>...
> Hi,
> I am quite new to Matlab and I am trying to implement a
AWGN
> channel ,at the moment, for Reed-Solomon codes
> My code is the following:
>
> m=4;
> k=9;
> for SNRdB = 1: 1: 15;
> data = randint(1,k,2^m-1);
> message = gf(data,m);
> enc = rsenc(message,2^m-1,k);
> c=randn(1,2^m-1);
> stdDev = 1/sqrt(2*10^(SNR/10));
> noise = c*stdDev*sqrt(2^m-1/k);
> cnoisy = enc + noise;
> error = gf(cnoisy,m);
> end
>
> The problem I think is when the variable 'error ' is
called
> because is the 'noise' is an array but the 'cnoisy' is a
> Galois field array, also an error occurs when the variable
> 'cnoisy' is called! (independently from the previous)
> But I don't know how to make it work.
> Thanks a lot.