Thanks for your response,
>What you could try is to adapt alpha of the single pole IIR, to get the same averaging with the increased sample rate.
I tried a variety of values without success but was not really sure what I was doing. Can you expand on what you meant by
"get the same averaging with the increased sample rate", and how to check this? I thought about the equation for the
single pole filter being subtracted from the original signal (that is, x[n]-y[n], where y[n] = a*x[n] + (1-a)*y[n-1]), but I didn't
see the relationship between this and the sample rate.
Here is a picture of the RX chain (which works for 4M but not 8, even with the omega adjustment)
I can put a scope after the USRP source and see some nice bursts; but I'm having trouble inspecting the signal after this
block in the chain..what is a good way to visualize what's happening after the quadrature demodulation?
>When this transceiver was implemented, the polyphase clock sync block
was not available yet. You are right, it should improve performance.
you switch to that block and see performance improvements, it would be
great if you made a pull request.
I made a pull request to parameterize the sample rate in the PHY block, so it wouldn't be hard coded in. If we can figure out these issues
I'd be happy to do some tests to compare the two and then make another pull request.
>I think there is no reason why that shouldn’t work. It would be
helpful if you could upload your flow graph, maybe there is
> a mistake
somewhere (the picture you posted did not show the USRP and xlating
here is my 2 channel receiver, showing the USRP and filters
(the variable chan_width is 2M).
Can you see some other issue? Maybe getting this working depends on increasing the samp_rate, which goes back to the first problem.