Hi Marcus, Thanks for reply. If set the decimation rate exactly the receive bandwidth then gnuradio will automaticly filter the signal at the receive bandwidth?
On Wed, Dec 29, 2010 at 9:22 AM, Marcus D. Leech <mle...@ripnet.com> wrote: > On 12/28/2010 08:05 PM, James Jordan wrote: > >> Hi Alexander, where the filter perform? In gnuradio? >> Since there is a filter, openbts must set it, how openbts set the filter? >> >> Regards. >> >> The OpenBTS software likely sets the incoming decimation rate to match as > closely as possible the desired receive bandwidth, > then it likely applies an FIR bandpass filter on the software side. > > This is, after all, Software Defined Radio, so it should be no surprise to > anyone that applications (OpenBTS, or whatever) use > filters implemented in software to condition the signals before further > processing. None of that requires the analog filtering to > work in anything other than an anti-alias mode. Filtering and bandwidth > reduction is performed first in the FPGA, in the digital > domain, and then on the host, with software, again in the digital domain. > Either Gnu Radio, or OpenBTS, or whatever. > > > -- > Marcus Leech > Principal Investigator > Shirleys Bay Radio Astronomy Consortium > http://www.sbrac.org > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio >
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