[Discuss-gnuradio] Received Signal Power ?

[bjoernm]

Hi,

I'm using the UCLA ZigBee PHY by Thomas Schmid, with the benchmark  
example from gnuradio.

Now I need the signal power of each received packet (at the receiver).  
For the signal
power computation:

P_S = sum ( all samples squared ) divided by number of samples

but the problem is where to fetch these samples, and how to make sure,  
that only samples
of the received packet are considered, and no noise...

1. is there a gnuradio block/function which would already perform this  
task of received
signal power computation, or RSSI determination, which I could  
use/edit for my task?

2. If not, where would be the best spot to capture the received  
samples? As the
clock_recovery looks to be too late, and capturing the packets earlier  
makes it hard to
distinguish between noise and received signal, as no clock recovery  
nor packet detection
is performed, yet.

I'd appreciate any help, thanks in advanced!