[Commit-gnuradio] r5604 - gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl

[trondeau]

Author: trondeau
Date: 2007-06-02 10:08:31 -0600 (Sat, 02 Jun 2007)
New Revision: 5604

Added:
   
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/ofdm_sync.py
Modified:
   
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/Makefile.am
   
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/ofdm_receiver.py
Log:
refactored ofdm receiver by breaking out synchronizer block into ofdm_sync

Modified: 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/Makefile.am
===================================================================
--- 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/Makefile.am
     2007-06-02 15:05:09 UTC (rev 5603)
+++ 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/Makefile.am
     2007-06-02 16:08:31 UTC (rev 5604)
@@ -41,6 +41,7 @@
        nbfm_tx.py              \
        ofdm_pkt.py             \
        ofdm_receiver.py        \
+       ofdm_sync.py            \
        pkt.py                  \
        psk.py                  \
        qam.py                  \

Modified: 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/ofdm_receiver.py
===================================================================
--- 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/ofdm_receiver.py
        2007-06-02 15:05:09 UTC (rev 5603)
+++ 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/ofdm_receiver.py
        2007-06-02 16:08:31 UTC (rev 5604)
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# Copyright 2004,2005,2006 Free Software Foundation, Inc.
+# Copyright 2006, 2007 Free Software Foundation, Inc.
 # 
 # This file is part of GNU Radio
 # 
@@ -22,135 +22,33 @@
 
 import math
 from gnuradio import gr
+from gnuradio.blksimpl.ofdm_sync import ofdm_sync
 
 class ofdm_receiver(gr.hier_block):
     def __init__(self, fg, fft_length, cp_length, occupied_tones, snr, ks1, 
ks2):
-        self.input = gr.add_const_cc(0) # Kluge that goes away with hier_block2
-
         self.fg = fg
-        
-        symbol_length = cp_length +  fft_length;
 
-        SNR = 10.0**(snr/10.0)
-        rho = SNR / (SNR + 1.0)
-
-        # ML Sync
-
-        # Energy Detection from ML Sync
-
-        # Create a delay line
-        #delayline = [0.0 for i in range(fft_length+1)]
-        #delayline[fft_length] = 1.0
-        #self.delay = gr.fir_filter_ccf(1,delayline)
-        self.delay = gr.delay(gr.sizeof_gr_complex, fft_length)
-        self.fg.connect(self.input, self.delay)
-
-        # magnitude squared blocks
-        self.magsqrd1 = gr.complex_to_mag_squared()
-        self.magsqrd2 = gr.complex_to_mag_squared()
-        self.adder = gr.add_ff()
-
-        moving_sum_taps = [rho/2 for i in range(cp_length)]
-        self.moving_sum_filter = gr.fir_filter_fff(1,moving_sum_taps)
+        bw = (float(occupied_tones) / float(fft_length)) / 2.0
+        tb = bw*0.08
+        chan_coeffs = gr.firdes.low_pass (1.0,                     # gain
+                                          1.0,                     # sampling 
rate
+                                          bw+tb,                   # midpoint 
of trans. band
+                                          tb,                      # width of 
trans. band
+                                          gr.firdes.WIN_HAMMING)   # filter 
type
+        self.chan_filt = gr.fft_filter_ccc(1, chan_coeffs)
         
-        self.fg.connect(self.input,self.magsqrd1)
-        self.fg.connect(self.delay,self.magsqrd2)
-        self.fg.connect(self.magsqrd1,(self.adder,0))
-        self.fg.connect(self.magsqrd2,(self.adder,1))
-        self.fg.connect(self.adder,self.moving_sum_filter)
-        
-
-        # Correlation from ML Sync
-        self.conjg = gr.conjugate_cc();
-        self.mixer = gr.multiply_cc();
-
-        movingsum2_taps = [1.0 for i in range(cp_length)]
-        self.movingsum2 = gr.fir_filter_ccf(1,movingsum2_taps)
-        
-        # Correlator data handler
-        self.c2mag = gr.complex_to_mag()
-        self.angle = gr.complex_to_arg()
-        self.fg.connect(self.input,(self.mixer,1))
-        self.fg.connect(self.delay,self.conjg,(self.mixer,0))
-        self.fg.connect(self.mixer,self.movingsum2,self.c2mag)
-        self.fg.connect(self.movingsum2,self.angle)
-
-        # ML Sync output arg, need to find maximum point of this
-        self.diff = gr.sub_ff()
-        self.fg.connect(self.c2mag,(self.diff,0))
-        self.fg.connect(self.moving_sum_filter,(self.diff,1))
-
-        #ML measurements input to sampler block and detect
-        nco_sensitivity = 1.0/fft_length
-        self.f2c = gr.float_to_complex()
-        self.sampler = gr.ofdm_sampler(fft_length,symbol_length)
-        self.pk_detect = gr.peak_detector_fb(0.2, 0.25, 30, 0.0001)
-        self.sample_and_hold = gr.sample_and_hold_ff()
-        self.nco = gr.frequency_modulator_fc(nco_sensitivity)
-        self.inv = gr.multiply_const_ff(-1)
-        self.sigmix = gr.multiply_cc()
-
-        # Mix the signal with an NCO controlled by the sync loop
-        self.fg.connect(self.input, (self.sigmix,0))
-        self.fg.connect(self.nco, (self.sigmix,1))
-        self.fg.connect(self.sigmix, (self.sampler,0))
-
-        # use the sync loop values to set the sampler and the NCO
-        # self.diff = theta
-        # self.angle = epsilon
-                          
-        self.fg.connect(self.diff, self.pk_detect)
-        use_dpll = 1
-
-        fixed_timing = 0
-        if fixed_timing:
-            # Use a fixed trigger point instead of sync block
-            peak_null = gr.null_sink(gr.sizeof_char)
-            data = 640*[0,]
-            data[639] = 1
-            peak_trigger = gr.vector_source_b(data, True)
-
-            self.fg.connect(self.pk_detect, peak_null)
-            self.fg.connect(peak_trigger, (self.sampler,1))
-            self.fg.connect(peak_trigger, (self.sample_and_hold,1))
-        else:
-            self.dpll = gr.dpll_bb(float(symbol_length),0.01)
-            if use_dpll:
-                self.fg.connect(self.pk_detect, self.dpll)
-                self.fg.connect(self.dpll, (self.sampler,1))
-                self.fg.connect(self.dpll, (self.sample_and_hold,1))
-            else:
-                self.fg.connect(self.pk_detect, (self.sampler,1))
-                self.fg.connect(self.pk_detect, (self.sample_and_hold,1))
-            
-        self.fg.connect(self.angle, (self.sample_and_hold,0))
-        self.fg.connect(self.sample_and_hold, self.inv, self.nco)
-        
-
-        if 1:
-            self.fg.connect(self.diff, gr.file_sink(gr.sizeof_float, 
"theta_f.dat"))
-            self.fg.connect(self.angle, gr.file_sink(gr.sizeof_float, 
"epsilon_f.dat"))
-            if fixed_timing:
-                self.fg.connect(peak_trigger, gr.file_sink(gr.sizeof_char, 
"peaks_b.dat"))
-            else:
-                self.fg.connect(self.pk_detect, gr.file_sink(gr.sizeof_char, 
"peaks_b.dat"))
-                if use_dpll:
-                    self.fg.connect(self.dpll, gr.file_sink(gr.sizeof_char, 
"dpll_pulses.dat"))
-                
-            self.fg.connect(self.sample_and_hold, 
gr.file_sink(gr.sizeof_float, "sample_and_hold_f.dat"))
-            self.fg.connect(self.nco, gr.file_sink(gr.sizeof_gr_complex, 
"nco_c.dat"))
-            self.fg.connect(self.input, gr.file_sink(gr.sizeof_gr_complex, 
"input_c.dat"))
-            self.fg.connect(self.sigmix, gr.file_sink(gr.sizeof_gr_complex, 
"output_c.dat"))
-
-
         win = [1 for i in range(fft_length)]
 
+        self.ofdm_sync = ofdm_sync(fg, fft_length, cp_length, snr)
         self.fft_demod = gr.fft_vcc(fft_length, True, win, True)
         self.ofdm_corr  = gr.ofdm_correlator(occupied_tones, fft_length,
                                              cp_length, ks1, ks2)
 
-        self.fg.connect(self.fft_demod, 
gr.file_sink(gr.sizeof_gr_complex*fft_length, "fft_out.dat"))
-        self.fg.connect(self.ofdm_corr, 
gr.file_sink(gr.sizeof_gr_complex*occupied_tones, "ofdm_corr_out.dat"))
+        self.fg.connect(self.chan_filt, self.ofdm_sync, self.fft_demod, 
self.ofdm_corr)
+        
+        if 1:
+            self.fg.connect(self.chan_filt, gr.file_sink(gr.sizeof_gr_complex, 
"chan_filt_c.dat"))
+            self.fg.connect(self.fft_demod, 
gr.file_sink(gr.sizeof_gr_complex*fft_length, "fft_out_c.dat"))
+            self.fg.connect(self.ofdm_corr, 
gr.file_sink(gr.sizeof_gr_complex*occupied_tones, "ofdm_corr_out_c.dat"))
 
-        self.fg.connect(self.sampler, self.fft_demod, self.ofdm_corr)
-        gr.hier_block.__init__(self, fg, self.input, self.ofdm_corr)
+        gr.hier_block.__init__(self, fg, self.chan_filt, self.ofdm_corr)

Added: 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/ofdm_sync.py
===================================================================
--- 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/ofdm_sync.py
                            (rev 0)
+++ 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/ofdm_sync.py
    2007-06-02 16:08:31 UTC (rev 5604)
@@ -0,0 +1,141 @@
+#!/usr/bin/env python
+#
+# Copyright 2007 Free Software Foundation, Inc.
+# 
+# This file is part of GNU Radio
+# 
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+# 
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+# 
+
+import math
+from gnuradio import gr
+
+class ofdm_sync(gr.hier_block):
+    def __init__(self, fg, fft_length, cp_length, snr):
+        self.fg = fg
+
+        self.input = gr.add_const_cc(0)
+
+        SNR = 10.0**(snr/10.0)
+        rho = SNR / (SNR + 1.0)
+        symbol_length = fft_length + cp_length
+
+        # ML Sync
+
+        # Energy Detection from ML Sync
+
+        # Create a delay line
+        self.delay = gr.delay(gr.sizeof_gr_complex, fft_length)
+        self.fg.connect(self.input, self.delay)
+
+        # magnitude squared blocks
+        self.magsqrd1 = gr.complex_to_mag_squared()
+        self.magsqrd2 = gr.complex_to_mag_squared()
+        self.adder = gr.add_ff()
+
+        moving_sum_taps = [rho/2 for i in range(cp_length)]
+        self.moving_sum_filter = gr.fir_filter_fff(1,moving_sum_taps)
+        
+        self.fg.connect(self.input,self.magsqrd1)
+        self.fg.connect(self.delay,self.magsqrd2)
+        self.fg.connect(self.magsqrd1,(self.adder,0))
+        self.fg.connect(self.magsqrd2,(self.adder,1))
+        self.fg.connect(self.adder,self.moving_sum_filter)
+        
+
+        # Correlation from ML Sync
+        self.conjg = gr.conjugate_cc();
+        self.mixer = gr.multiply_cc();
+
+        movingsum2_taps = [1.0 for i in range(cp_length)]
+        self.movingsum2 = gr.fir_filter_ccf(1,movingsum2_taps)
+        
+        # Correlator data handler
+        self.c2mag = gr.complex_to_mag()
+        self.angle = gr.complex_to_arg()
+        self.fg.connect(self.input,(self.mixer,1))
+        self.fg.connect(self.delay,self.conjg,(self.mixer,0))
+        self.fg.connect(self.mixer,self.movingsum2,self.c2mag)
+        self.fg.connect(self.movingsum2,self.angle)
+
+        # ML Sync output arg, need to find maximum point of this
+        self.diff = gr.sub_ff()
+        self.fg.connect(self.c2mag,(self.diff,0))
+        self.fg.connect(self.moving_sum_filter,(self.diff,1))
+
+        #ML measurements input to sampler block and detect
+        nco_sensitivity = 1.0/fft_length
+        self.f2c = gr.float_to_complex()
+        self.sampler = gr.ofdm_sampler(fft_length,symbol_length)
+        self.pk_detect = gr.peak_detector_fb(0.2, 0.25, 30, 0.0001)
+        self.sample_and_hold = gr.sample_and_hold_ff()
+        self.nco = gr.frequency_modulator_fc(nco_sensitivity)
+        self.inv = gr.multiply_const_ff(-1)
+        self.sigmix = gr.multiply_cc()
+
+        # Mix the signal with an NCO controlled by the sync loop
+        self.fg.connect(self.input, (self.sigmix,0))
+        self.fg.connect(self.nco, (self.sigmix,1))
+        self.fg.connect(self.sigmix, (self.sampler,0))
+
+        # use the sync loop values to set the sampler and the NCO
+        #     self.diff = theta
+        #     self.angle = epsilon
+                          
+        self.fg.connect(self.diff, self.pk_detect)
+        use_dpll = 1
+
+        fixed_timing = 0
+        if fixed_timing:
+            # Use a fixed trigger point instead of sync block
+            peak_null = gr.null_sink(gr.sizeof_char)
+            data = 640*[0,]
+            data[639] = 1
+            peak_trigger = gr.vector_source_b(data, True)
+
+            self.fg.connect(self.pk_detect, peak_null)
+            self.fg.connect(peak_trigger, (self.sampler,1))
+            self.fg.connect(peak_trigger, (self.sample_and_hold,1))
+        else:
+            self.dpll = gr.dpll_bb(float(symbol_length),0.01)
+            if use_dpll:
+                self.fg.connect(self.pk_detect, self.dpll)
+                self.fg.connect(self.dpll, (self.sampler,1))
+                self.fg.connect(self.dpll, (self.sample_and_hold,1))
+            else:
+                self.fg.connect(self.pk_detect, (self.sampler,1))
+                self.fg.connect(self.pk_detect, (self.sample_and_hold,1))
+            
+        self.fg.connect(self.angle, (self.sample_and_hold,0))
+        self.fg.connect(self.sample_and_hold, self.inv, self.nco)
+
+        if 1:
+            self.fg.connect(self.diff, gr.file_sink(gr.sizeof_float, 
"theta_f.dat"))
+            self.fg.connect(self.angle, gr.file_sink(gr.sizeof_float, 
"epsilon_f.dat"))
+            if fixed_timing:
+                self.fg.connect(peak_trigger, gr.file_sink(gr.sizeof_char, 
"peaks_b.dat"))
+            else:
+                self.fg.connect(self.pk_detect, gr.file_sink(gr.sizeof_char, 
"peaks_b.dat"))
+                if use_dpll:
+                    self.fg.connect(self.dpll, gr.file_sink(gr.sizeof_char, 
"dpll_b.dat"))
+
+            self.fg.connect(self.sigmix, gr.file_sink(gr.sizeof_gr_complex, 
"sigmix_c.dat"))
+            self.fg.connect(self.sampler, 
gr.file_sink(gr.sizeof_gr_complex*fft_length, "sampler_c.dat"))
+            self.fg.connect(self.sample_and_hold, 
gr.file_sink(gr.sizeof_float, "sample_and_hold_f.dat"))
+            self.fg.connect(self.nco, gr.file_sink(gr.sizeof_gr_complex, 
"nco_c.dat"))
+            self.fg.connect(self.input, gr.file_sink(gr.sizeof_gr_complex, 
"input_c.dat"))
+
+        gr.hier_block.__init__(self, fg, self.input, self.sampler)