Hi everyone,

I’m hoping for some advice on using RFNoC for a spectrum analysis application 
(I have another hardware clocking question that I’m going to ask separately).

Context: we need to continuously stream channel power in a bank of 8 contiguous 
10 MHz bands on short (a few microseconds) time scales. To manage the initial 
deluge of IQ, I’d like to use an FPGA to perform a 512-point FFT and then 
reduce the volume of data by summing up mag2 across frequency to give channel 
power. The resulting stream of 8 channel power readings every few microseconds 
is then pretty manageable for transport and processing on the host.

After looking at the RFNoC block list, the (wishful thinking? :-)) 
implementation in my head looks like this:

(Radio) → Window → FFT (mag2 output) → Vector IIR to sum across frequency bins 
→ Keep 1 in N → (Stream to host)

Some questions have come up on this:

  1.  Does the Vector IIR at the output of an FFT operate across time or 
frequency? For “Keep 1 in N,” there’s a clear flag to determine whether the 
operation is applied by sample or by packet, but I don’t see anything about 
which of these “Moving Average” “Vector IIR” operate on.
  2.  Are there any obvious fixed-point traps in doing this?
  3.  Are there any other pitfalls that I’m missing here?

Thanks in advance for any ideas!

Dan Kuester
(he/him)
Project Lead, Spectrum Sensing and Noise
Communications Technology Laboratory

National Institute of Standards and Technology
325 Broadway St., Boulder, CO 80305, USA

_______________________________________________
USRP-users mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to