Re: [Discuss-gnuradio] anyone help me understand usrp fpga code fragment which count rssi

[Marcus D. Leech]

On 08/04/2011 09:52 PM, Page Jack wrote:
> Hi Colby,
> I know cheaper in hardware, but now I don't understand how using IIR
> filter can compute the RSSI? 
>
>
The power estimate in a complex channel is computed as:

AVG(I**2 + Q**2)

An IIR filter is a simple way of approximating the AVG part of that
equation, and computing the
  absolute value is another approximation for the I**2 and Q**2 part. 
You'll notice in the RSSI
  section that it essentially computes the absolute value.




-- 
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org