[Commit-gnuradio] r9694 - in gnuradio/trunk: gnuradio-core/src/python/gnuradio/blks2impl gnuradio-examples/python/usrp

[n4hy]

Author: n4hy
Date: 2008-10-01 14:42:43 -0600 (Wed, 01 Oct 2008)
New Revision: 9694

Modified:
   gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/wfm_rcv_pll.py
   gnuradio/trunk/gnuradio-examples/python/usrp/usrp_wfm_rcv_pll.py
Log:
pll bandwidth optimized to more nearly meet Carson's rule.  The 19 kHz pilot 
recovery will soon be replace by polyphase channelizer trick

Modified: 
gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/wfm_rcv_pll.py
===================================================================
--- gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/wfm_rcv_pll.py   
2008-10-01 17:18:13 UTC (rev 9693)
+++ gnuradio/trunk/gnuradio-core/src/python/gnuradio/blks2impl/wfm_rcv_pll.py   
2008-10-01 20:42:43 UTC (rev 9694)
@@ -39,7 +39,7 @@
        gr.hier_block2.__init__(self, "wfm_rcv_pll",
                                gr.io_signature(1, 1, gr.sizeof_gr_complex), # 
Input signature
                                gr.io_signature(1, 2, gr.sizeof_float))      # 
Output signature
-        bandwidth = 180e3
+        bandwidth = 250e3
         audio_rate = demod_rate / audio_decimation
 
 
@@ -49,7 +49,7 @@
         # input: complex; output: float
         alpha = 0.25*bandwidth * math.pi / demod_rate
         beta = alpha * alpha / 4.0
-        max_freq = 2.0*math.pi*100e3/demod_rate
+        max_freq = 2.0*math.pi*90e3/demod_rate
             
         self.fm_demod = gr.pll_freqdet_cf (alpha,beta,max_freq,-max_freq)
 

Modified: gnuradio/trunk/gnuradio-examples/python/usrp/usrp_wfm_rcv_pll.py
===================================================================
--- gnuradio/trunk/gnuradio-examples/python/usrp/usrp_wfm_rcv_pll.py    
2008-10-01 17:18:13 UTC (rev 9693)
+++ gnuradio/trunk/gnuradio-examples/python/usrp/usrp_wfm_rcv_pll.py    
2008-10-01 20:42:43 UTC (rev 9694)
@@ -81,13 +81,13 @@
         self.u = usrp.source_c()                    # usrp is data source
 
         adc_rate = self.u.adc_rate()                # 64 MS/s
-        usrp_decim = 160
+        usrp_decim = 200
         self.u.set_decim_rate(usrp_decim)
-        usrp_rate = adc_rate / usrp_decim           #  400 kS/s
+        usrp_rate = adc_rate / usrp_decim           #  320 kS/s
         chanfilt_decim = 1
         demod_rate = usrp_rate / chanfilt_decim
         audio_decimation = 10
-        audio_rate = 6*demod_rate / audio_decimation/5  # 48 kHz
+        audio_rate = 3*demod_rate / audio_decimation/2  # 48 kHz
 
         if options.rx_subdev_spec is None:
             options.rx_subdev_spec = pick_subdevice(self.u)
@@ -100,12 +100,13 @@
                                             usrp_rate,   # sampling rate
                                             90e3,        # passband cutoff
                                             30e3,        # transition bandwidth
-                                            60)          # stopband attenuation
-#        print len(chan_filt_coeffs)
+                                            70,          # stopband attenuation
+                                            gr.firdes.WIN_BLACKMAN)
+        print len(chan_filt_coeffs)
         chan_filt = gr.fir_filter_ccf (chanfilt_decim, chan_filt_coeffs)
 
-        self.rchan_sample = blks2.rational_resampler_fff(6,5)
-        self.lchan_sample = blks2.rational_resampler_fff(6,5)
+        self.rchan_sample = blks2.rational_resampler_fff(3,2)
+        self.lchan_sample = blks2.rational_resampler_fff(3,2)
 
 
         #self.guts = blks2.wfm_rcv (demod_rate, audio_decimation)