Using PFB resampler to do the RRC filtering on the modulator. This along with the...

diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py b/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py
index a692e7d1fc407a152b2549d638831d8aabe13551..b2cc278543c5e99a0f4420e9735006bdcbab167d 100644 (file)
--- a/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py
+++ b/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py
@@ -26,7 +26,7 @@ differential BPSK modulation and demodulation.
 """
 
 from gnuradio import gr, gru, modulation_utils
-from math import pi, sqrt
+from math import pi, sqrt, ceil
 import psk
 import cmath
 from pprint import pprint
@@ -86,8 +86,6 @@ class dbpsk2_mod(gr.hier_block2):
         if not isinstance(self._samples_per_symbol, int) or self._samples_per_symbol < 2:
             raise TypeError, ("sbp must be an integer >= 2, is %d" % self._samples_per_symbol)
         
-       ntaps = 11 * self._samples_per_symbol
-
         arity = pow(2,self.bits_per_symbol())
         
         # turn bytes into k-bit vectors
@@ -103,16 +101,15 @@ class dbpsk2_mod(gr.hier_block2):
 
         self.chunks2symbols = gr.chunks_to_symbols_bc(psk.constellation[arity])
 
-        # pulse shaping filter
-       self.rrc_taps = gr.firdes.root_raised_cosine(
-           self._samples_per_symbol,   # gain (samples_per_symbol since we're
-                                        # interpolating by samples_per_symbol)
-           self._samples_per_symbol,   # sampling rate
-           1.0,                        # symbol rate
-           self._excess_bw,            # excess bandwidth (roll-off factor)
+        nfilts = 32
+        ntaps = nfilts * 11 * self._samples_per_symbol      # make nfilts filters of ntaps each
+        self.rrc_taps = gr.firdes.root_raised_cosine(
+            nfilts,          # gain
+            nfilts,          # sampling rate based on 32 filters in resampler
+            1.0,             # symbol rate
+            self._excess_bw, # excess bandwidth (roll-off factor)
             ntaps)
-       self.rrc_filter = gr.interp_fir_filter_ccf(self._samples_per_symbol,
-                                                   self.rrc_taps)
+        self.rrc_filter = gr.pfb_arb_resampler_ccf(self._samples_per_symbol, self.rrc_taps)
 
        # Connect
         self.connect(self, self.bytes2chunks, self.symbol_mapper, self.diffenc,
@@ -244,16 +241,14 @@ class dbpsk2_demod(gr.hier_block2):
         self.agc = gr.agc2_cc(0.6e-1, 1e-3, 1, 1, 100)
         #self.agc = gr.feedforward_agc_cc(16, 1.0)
 
-
         # Frequency correction
         self.freq_recov = gr.fll_band_edge_cc(self._samples_per_symbol, self._excess_bw,
-                                              11*self._samples_per_symbol,
+                                              11*int(self._samples_per_symbol),
                                               self._freq_alpha, self._freq_beta)
-                                              
 
         # symbol timing recovery with RRC data filter
         nfilts = 32
-        ntaps = 11 * samples_per_symbol*nfilts
+        ntaps = 11 * int(self._samples_per_symbol*nfilts)
         taps = gr.firdes.root_raised_cosine(nfilts, nfilts,
                                             1.0/float(self._samples_per_symbol),
                                             self._excess_bw, ntaps)