FM Receive in gnuradio using USRP(type b100)

Question

I am using USRP b100 and i want to receive fm audio. it does not give proper sound here is the link of screen shot of simulation, configuration of some blocks

https://github.com/faydal077/gnuradio.git

it mainly says "The request decimation is odd; the user should expect CIC rolloff. Select an even decimation to ensure that a half filter is enabled. decimation = dsp_rate/samp_rate->31" i have tried decimation as an even number as 65.536M but problem did not solved. Thanks in advance

Answer 1

I'm not sure the B100 supports these sampling rates.

The USRP source does have have a parameter "Clock Rate". Please try setting it to samp_rate*4.

If that doesn't work, I'm afraid the sampling rate you want is impossible.

But: the sampling rate you want doesn't even make sense; your audio sampling rate is 48 kHz; the WBFM receiver must decimate by an integer, which means that the rate of samples going in must be an integer multiple of that.

You use 10 as decimation there. So, in theory, your IQ sampling rate going into the WBFM block must be 48000·10 = 480000; but you feed in a completely different rate.