[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] USRP Custom Filter Taps
From: |
Matt Ettus |
Subject: |
Re: [Discuss-gnuradio] USRP Custom Filter Taps |
Date: |
Thu, 05 Oct 2006 13:34:39 -0700 |
User-agent: |
Thunderbird 1.5.0.7 (X11/20060922) |
Daniel Garcia wrote:
> I am working on an NTSC receiver using the USRP/TVRX board. I am tunning the
> board to 63.25 MHz with decimation set to 10; this gives me 6.4 MHz of
> bandwidth. The NTSC channel is 6 MHz wide so with these settings I get some
> interference from the adjacent channels.
>
> Is there a way to set the filter taps used by the USRP so that I could make a
> filter to remove the frequency infomation at the extreme right and left of
> the sampled data? I can use an FIR filter in the PYTHON runtime but it uses
> lots of CPU power.
>
>
Yes, you can change the filter taps in the FPGA. See the halfband (HB)
verilog code.
> I read on a previous thread that it is possible to invert the spectrum of the
> sampled signal so that the tuned frequency would be the FM carrier. The end
> result being a stream from the USRP where 0 Hz is the center frequency of the
> audio carrier the the video carrier is at 4.5 MHz. Is this possible? The
> advantage here is that the baseband audio does not need to be shifted before
> fm demodulation; also the video carrier does not need to be shifted before
> demodulation (AM).
>
Not sure what you're looking for here.
Matt
- Re: [Discuss-gnuradio] USRP Custom Filter Taps,
Matt Ettus <=