Re: [Discuss-gnuradio] rssi questions

[Eric Blossom]

On Thu, Aug 16, 2007 at 12:36:05PM -0400, George Nychis wrote:
> Okay, so I'm a little bit intimidated, I'm not too familiar at this level.
> 
> So I'm going to ask for some help me through with baby step questions :)
> 
> We managed to get reading/writing to some unused registers working 
> through in-band C/S packets.  So, we're ready to use this code to pass 
> information from the host to FPGA about the daughterboard configuration.
> 
> We want to compute the RSSI in dB on the FPGA, we're not even interested 
> in the FPGA responding back with the RSSI at this point.
> 
> 1. What exact information needs to be shared?

Some measure of the received signal strength.

> 2. Where can we get the information?  I'm assuming when the 
> daughterboards are initialized most of this information is available.

For the time being, assume that you are getting it from the "Post ADC"
rssi block, rssi.v.  See also usrp_std.v (search for rssi).

> 3. How exactly would you compute the RSSI in dB given this information 
> on the FPGA efficiently?  Equation? :)

For now, don't worry about getting it into dB on the FPGA.
The representation can be manipulated on the host.

> Thanks!
> George

Eric