RE: [Discuss-gnuradio] A problem of the turbo channel coding!

[Shucai Xiao]

Also, if there is any existing channel encoding/decoding modules that use
short/char as input and use the same type as the output, too?

Thanks

Best regards

Shucai

-----Original Message-----
From: Brian Padalino [mailto:address@hidden 
Sent: 2008年9月12日 8:54
To: Shucai Xiao
Cc: address@hidden
Subject: Re: [Discuss-gnuradio] A problem of the turbo channel coding!

On Fri, Sep 12, 2008 at 8:37 AM, Shucai Xiao <address@hidden> wrote:
> Hi, all
>
>
>
>          Currently, I am trying to establish a data transmission system
> using the Viterbi coding method as the channel coding.
>
>          I found a problem that the output of the coding module is short
> type,
>
>          Enc = trellis.encoder_ss(f, 0)
>
>
>
>          While the decode module needs a float type
>
>          Va = trellis.viterbi_s(f, K, 0, -1)
>
>
>
>          Can some one tell me how to make them compatible?

The encoder works on hard data bits that you want to transmit over the air.

The decoder works on soft decision bits that you have received.

Scale your encoder bits to be within the soft decision range.

Brian