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[Discuss-gnuradio] Re: FSK now (really) working at 100kbit/sec
From: |
Eric Blossom |
Subject: |
[Discuss-gnuradio] Re: FSK now (really) working at 100kbit/sec |
Date: |
Fri, 15 Apr 2005 10:41:42 -0700 |
User-agent: |
Mutt/1.5.6i |
On Fri, Apr 15, 2005 at 03:37:27PM +0000, Deqiang chen wrote:
> hello, Eric,
>
> I remembered there is an annoucement that FSK can work at 100kbps.
> So I dig it out and take a look at the source code for the FSK (
> fsk_rx.py) . I am a little surprised
> that there are no time recovery there.
> My understanding is that for fsk, if you use noncoherent
> demodulation, you would not need the phase information. However,
> you still need to know the timing in order to correctly sampling the
> output of correlator or matched filter. Could you give a hint of
> what is going on here ?
> david
The output rate of gr.quadrature_demod_cf is 8 times the symbol rate.
The selection of the center of the bit is done in gr.simple_correlator.
It watches for a pseudo random sync pattern at the beginning of
each packet and uses this to figure out which of the possible alignments
is best. A similar technique is used in Bluetooth.
Eric
- Re: [Discuss-gnuradio] No module named wx, (continued)
Re: [Discuss-gnuradio] No module named wx, Eric Blossom, 2005/04/14
[Discuss-gnuradio] Re: FSK now (really) working at 100kbit/sec, Deqiang chen, 2005/04/15
Re: [Discuss-gnuradio] Re: FSK now (really) working at 100kbit/sec, Matt Ettus, 2005/04/15
[Discuss-gnuradio] Re: FSK now (really) working at 100kbit/sec,
Eric Blossom <=
Re: [Discuss-gnuradio] No module named wx, Eric Blossom, 2005/04/14
Re: [Discuss-gnuradio] No module named wx, Angilberto Muniz Sb, 2005/04/15