Re: [Discuss-gnuradio] Question on gr.wavfile_source

[Brook Lin]

Thanks Martin for your reply. I gave a larger gain, but still doesn't work.
And I think I was using AM modulation in my tx_path, wasn't it? And I used
usrp_am_mw_rcv.py to receive my transmitted signal. Should I use
gr.interp_fir_filter_fff() on the transmitter side for am modulation? Are
the parameters correct in optfir.low_pass()?

        interp_factor = usrp_rate/audio_rate

        interp_taps = optfir.low_pass (interp_factor,           # gain
                                            usrp_rate,   # sampling rate
                                            8e3,        # passband cutoff
8e3
                                            12e3,       # stopband cutoff
12e3
                                            1.0,         # passband ripple
                                            60)          # stopband
attenuation
        print 'len(interp_taps)',len(interp_taps)
        self.interpolator = gr.interp_fir_filter_fff (interp_factor,
interp_taps)

Thanks in advance for any reply.

Brook


Martin Braun-3 wrote:
> 
> I can't spot an exact problem, but two things do come to mind:
> 1) Your gain is awfully low, you're hardly using the dynamic range of
> the ADC. Try something like 20000.
> 2) Use an analog modulation, such as AM (w/ carrier) or FM.
> 
> MB
> -- 
> Dipl.-Ing. Martin Braun           Phone: +49-(0)721-608 3790
> Institut fuer Nachrichtentechnik  Fax:   +49-(0)721-608 6071
> Universitaet Karlsruhe (TH)       http://www.int.uni-karlsruhe.de/
> 
>  
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> 
> 

-- 
View this message in context: 
http://www.nabble.com/Question-on-gr.wavfile_source-tp24176428p24208903.html
Sent from the GnuRadio mailing list archive at Nabble.com.