[Discuss-gnuradio] how to get the signal strength in gr-ieee802-11

Hi all,

Sorry to bother you. Recently, I'm working with the gr-ieee802-11. I need to know the signal power strength of a packet received by usrp. I mean, not the rx_gain variable of course. Is there any api in the gr-ieee802-11 ? Or how can I do ? 

Any suggestions would be appreciated.

Best Regards.

Siyu