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soft demapping of qpsk

Started by mrakesh85 ●April 20, 2009
Hai,
    I am using a 1/2 rate convolution  encoder and after encoding I am
mapping the bits to qpsk constellation.My received signal is of form y =
a*s+n. Where 'a' is due to channel fading 's' is qpsk symbol and 'n' is
noise.I estimated 'a' (I know 'a') .I have no idea about soft qpsk
demapper.
that will take N symbols and outputs 2*N coded soft bits.
 
Thank You
M.Rakesh
Reply by cpshah99 ●April 20, 20092009-04-20
>Hai,
>    I am using a 1/2 rate convolution  encoder and after encoding I am
>mapping the bits to qpsk constellation.My received signal is of form y =
>a*s+n. Where 'a' is due to channel fading 's' is qpsk symbol and 'n' is
>noise.I estimated 'a' (I know 'a') .I have no idea about soft qpsk
>demapper.
>that will take N symbols and outputs 2*N coded soft bits.
> 
>Thank You
>M.Rakesh
> 
>
>
>


%%%

Read section 2 of this paper.

http://www.lnt.ei.tum.de/mitarbeiter/goertz/globecom03.pdf


IHTH

Chintan
Reply by Vladimir Vassilevsky ●April 20, 20092009-04-20
STUPIDENT

mrakesh85 wrote:


> Hai,
>     I am using a 1/2 rate convolution  encoder and after encoding I am
> mapping the bits to qpsk constellation.My received signal is of form y =
> a*s+n. Where 'a' is due to channel fading 's' is qpsk symbol and 'n' is
> noise.I estimated 'a' (I know 'a') .I have no idea about soft qpsk
> demapper.
> that will take N symbols and outputs 2*N coded soft bits.
>  
> Thank You
> M.Rakesh
>  
> 
>
Reply by rickman ●April 20, 20092009-04-20
On Apr 20, 6:21&#4294967295;am, "mrakesh85" <munagalarak...@yahoo.com> wrote:

> Hai,
> &#4294967295; &#4294967295; I am using a 1/2 rate convolution &#4294967295;encoder and after encoding I am
> mapping the bits to qpsk constellation.My received signal is of form y =
> a*s+n. Where 'a' is due to channel fading 's' is qpsk symbol and 'n' is
> noise.I estimated 'a' (I know 'a') .I have no idea about soft qpsk
> demapper.
> that will take N symbols and outputs 2*N coded soft bits.
>
> Thank You
> M.Rakesh


Nothing to add, just wanted to change the subject back.