I'd like to implement a FHSS receiver in GNU Radio, using a USRP B210. The total bandwidth of the signal is about 30 MHz, with each message having a bandwidth of about 200kHz. When I attempt to sample the signal to account for the full 30MHz bandwidth, I receive Overflow notifications. I've considered sampling the signal at a significantly lower rate and induce aliasing so as to receive the messages within the lower bandwidth, but so far I've been unsuccessful in bypassing the anti-aliasing filter. My understanding is that, while the analog antialising filter on the USRP can be set to larger than the bandwidth required for my sampling rate, the digital filter is determined by the sampling rate and cannot be changed.
My questions are:
- Can the digital anti-aliasing filter be bypassed or changed in any way?
- Can the USRP source be programmed to give me samples at a decimated rate, so that I can sample at the higher rate and the load on my system will result from the lower sample rate?