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From: | yeran |
Subject: | Re: [Discuss-gnuradio] time_recov and freq_recov in generic_mod_demod |
Date: | Wed, 5 Jun 2013 14:50:23 +0000 |
And also, if I want to test the frequency at right after the usrp source and after time_recov block at the receiver, what can I do?
Thanks! From: address@hidden To: address@hidden Date: Wed, 5 Jun 2013 14:47:26 +0000 Subject: [Discuss-gnuradio] time_recov and freq_recov in generic_mod_demod Hi everyone,
I have a question in understanding the generic_mod_demod.py. As I looked up from the documents, it was said that the signal after the usrp source at the receiver, is baseband signal, whose central frequency is around 0 Hz, and already take off the carrier frequency. But in the demodulation, there are still freq_recov and time_recov block. Are they at the symbol level? Since when I add a file_sink after the time_recov, and try to do channel estimation, the plot I get looks like sine wave, making me think if the carrier frequency is still there. I'm quite confused with how the benchmark, actually the demodulation in generic_mod_demod.py works. When does the carrier frequency is taken off? What's the function of the channel_filter, time_recov (including the rrc filter) and freq_recov? Can anyone give me some suggestions on how the blocks work? And any possible answers why the channel estimation I get in narrowband looks like sine wave? Thanks a lot! Ada _______________________________________________ Discuss-gnuradio mailing list address@hidden https://lists.gnu.org/mailman/listinfo/discuss-gnuradio |
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