Re: [Discuss-gnuradio] Two samples per symbol..how can we use both samples to create a symbol during demod!!

[Stefan Brüns]

On Tuesday 29 September 2009 05:16:16 Bishal Thapa wrote:
> Dear Thomas and Tim,
>   Thank you for replying all my questions previously. I have another
> question for the list. Hope you don't mind. I wrote a demod for dbpsk. I
> had to because I am spreading/despreading packets using dbpsk modulation.
> DBPSK demod turned out pretty easy, except I committed a serious mistake
> that didn't take its toll until very much later. Since, gnuradio is
> collecting two samples per symbol, I hapazardly was skipping every other
> sample, and just using one sample per symbol to demodulate the dbpsk
> samples. This is obviously wrong, now I realize that a hard way. Could
> someone, a DSP being, or the gnuradio-dbpsk- demod developer help me
> understand, how can i combine both samples to decide on one symbol? I am
> doing a hack without
> understanding much. I am taking average of two samples and then using it to
> calculate phase difference with the next bit-sample. This is a hazard, I
> know :(. Please shed some light on these two samples per symbol business,
> please!!
>
> Sincerely,

Just use the gr_mpsk_receiver block

Stefan

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