usrp_rx_nogui Namespace Reference


Classes

class  usrp_src
 Create a USRP source object supplying complex floats. More...
class  app_top_block

Functions

def main

Variables

dictionary demod_params
 This example application demonstrates receiving and demodulating different types of signals using the USRP.

Function Documentation

def usrp_rx_nogui::main (  ) 


Variable Documentation

Initial value:

{
                'AM'  : (250, 16, 1,  5000,   8000, blks2.demod_10k0a3e_cf),
                'FM'  : (250,  8, 4,  8000,   9000, blks2.demod_20k0f3e_cf),
                'WFM' : (250,  1, 8, 90000, 100000, blks2.demod_200kf3e_cf)
               }
This example application demonstrates receiving and demodulating different types of signals using the USRP.

A receive chain is built up of the following signal processing blocks:

USRP - Daughter board source generating complex baseband signal. CHAN - Low pass filter to select channel bandwidth RFSQL - RF squelch zeroing output when input power below threshold AGC - Automatic gain control leveling signal at [-1.0, +1.0] DEMOD - Demodulation block appropriate to selected signal type. This converts the complex baseband to real audio frequencies, and applies an appropriate low pass decimating filter. CTCSS - Optional tone squelch zeroing output when tone is not present. RSAMP - Resampler block to convert audio sample rate to user specified sound card output rate. AUDIO - Audio sink for playing final output to speakers.

The following are required command line parameters:

-f FREQ USRP receive frequency -m MOD Modulation type, select from AM, FM, or WFM

The following are optional command line parameters:

-R SUBDEV Daughter board specification, defaults to first found -c FREQ Calibration offset. Gets added to receive frequency. Defaults to 0.0 Hz. -g GAIN Daughterboard gain setting. Defaults to mid-range. -o RATE Sound card output rate. Defaults to 32000. Useful if your sound card only accepts particular sample rates. -r RFSQL RF squelch in db. Defaults to -50.0. -p FREQ CTCSS frequency. Opens squelch when tone is present.

Once the program is running, ctrl-break (Ctrl-C) stops operation.

Please see fm_demod.py and am_demod.py for details of the demodulation blocks.


Generated on Thu Mar 5 09:04:04 2009 for GNU Radio 3.1.3 by  doxygen 1.5.8