usrp_flex_all.py

这是用python语言写的一个数字广播的信号处理工具包。利用它

#!/usr/bin/env python

from gnuradio import gr, gru, usrp, optfir, eng_notation, blks2, pager
from gnuradio.eng_option import eng_option
from optparse import OptionParser
from string import split, join, printable
import time

class app_top_block(gr.top_block):
    def __init__(self, options, queue):
	gr.top_block.__init__(self, "usrp_flex_all")

        if options.from_file is not None:
            src = gr.file_source(gr.sizeof_gr_complex, options.from_file)
            if options.verbose:
                print "Reading samples from file", options.from_file
        else:
            src = usrp.source_c()
            if options.rx_subdev_spec is None:
                options.rx_subdev_spec = usrp.pick_rx_subdevice(src)
            subdev = usrp.selected_subdev(src, options.rx_subdev_spec)
            src.set_mux(usrp.determine_rx_mux_value(src, options.rx_subdev_spec))
            src.set_decim_rate(20)
            result = usrp.tune(src, 0, subdev, 930.5e6+options.calibration)
            if options.verbose:
                print "Using", subdev.name(), " for receiving."
                print "Tuned USRP to", 930.5e6+options.calibration
                
        taps = gr.firdes.low_pass(1.0,
                                  1.0,
                                  1.0/128.0*0.4,
                                  1.0/128.0*0.1,
                                  gr.firdes.WIN_HANN)

        if options.verbose:
            print "Channel filter has", len(taps), "taps"

        bank = blks2.analysis_filterbank(128, taps)
        self.connect(src, bank)

        if options.log and options.from_file == None:
            src_sink = gr.file_sink(gr.sizeof_gr_complex, 'usrp.dat')
            self.connect(src, src_sink)

        for i in range(128):
	    if i < 64:
		freq = 930.5e6+i*25e3
	    else:
		freq = 928.9e6+(i-64)*25e3

	    if (freq < 929.0e6 or freq > 932.0e6):
                self.connect((bank, i), gr.null_sink(gr.sizeof_gr_complex))
	    else:
            	self.connect((bank, i), pager.flex_demod(queue, freq, options.verbose, options.log))
                if options.log:
                    self.connect((bank, i), gr.file_sink(gr.sizeof_gr_complex, 'chan_'+'%3.3f'%(freq/1e6)+'.dat'))

def main():
    parser = OptionParser(option_class=eng_option)
    parser.add_option("-R", "--rx-subdev-spec", type="subdev",
                      help="select USRP Rx side A or B (default=first daughterboard found)")
    parser.add_option("-c", "--calibration", type="eng_float", default=0.0,
                      help="set frequency offset to Hz", metavar="Hz")
    parser.add_option("-g", "--gain", type="int",
                      help="set RF gain", metavar="dB")
    parser.add_option("-F", "--from-file", default=None,
                      help="Read from file instead of USRP")
    parser.add_option("-l", "--log", action="store_true", default=False,
                      help="log flowgraph to files (LOTS of data)")
    parser.add_option("-v", "--verbose", action="store_true", default=False,
                      help="display debug output")
    (options, args) = parser.parse_args()

    if options.verbose:
        print options

    queue = gr.msg_queue()
    tb = app_top_block(options, queue)

    try:
        tb.start()
	while 1:
	    if not queue.empty_p():
		msg = queue.delete_head() # Blocking read
		page = join(split(msg.to_string(), chr(128)), '|')
		disp = []
		for n in range(len(page)):
		    if ord(page[n]) < 32:
			disp.append('.')
		    else:
			disp.append(page[n])
		print join(disp, '')
						
	    else:
		time.sleep(1)

    except KeyboardInterrupt:
        tb.stop()
    
if __name__ == "__main__":
    main()