Re: [Discuss-gnuradio] Inquiry about automatic gain control

[bdannan]

Matt,

So it is possible to be implemented in code on the verilog side? If so, do you
have any suggestions on where to start?

Thanks for your help

Regards,
Benjamin Dannan
Quoting Matt Ettus <address@hidden>:

> address@hidden wrote:
> > Brian,
> >
> > If you refer to the usrp\fpga\sdr_lib\adc_interface.v
> >
> > this is a comment stating: \\level sensing for AGC
> > on line 67 of the verilog code file.
> >
> > I have read on the wiki that AGC can be implemented by moving resistors
> around,
> > can you elaborate on this: which resistors, and on what board?
> >
> > I am assuming that there is some sort of feedback loop for the FPGA to an
> > amplifier which uses the RSSI, is there not one? 
> >   
> 
> 
> By moving some resistors around you can implement a completely analog 
> AGC function on the RFX900, 1200, 1800, and 2400.  It will not work on 
> the RFX400.
> 
> In general, there are many ways you can implement AGC, depending on 
> where you implement the RSSI sensing and the control functions.  Nothing 
> has been done to prevent you from doing any of these, but it is an 
> exercise left to the user, as they say.
> 
> Matt
>