Updating the arb. resampler to use the optfir filter that provides better specificati...

[debian/gnuradio] / gnuradio-core / src / python / gnuradio / blks2impl / pfb_arb_resampler.py

diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py b/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py
index e40d9636ad8fdf9fdfc9e75c3703d732a13297a4..c4e496c45acbf2c2d9ada86df0a9fefde67e13fe 100644 (file)
--- a/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py
+++ b/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py
@@ -20,7 +20,7 @@
 # Boston, MA 02110-1301, USA.
 # 
 
 # Boston, MA 02110-1301, USA.
 # 
 

-from gnuradio import gr
+from gnuradio import gr, optfir

 
 class pfb_arb_resampler_ccf(gr.hier_block2):
     '''
 
 class pfb_arb_resampler_ccf(gr.hier_block2):
     '''


@@ -31,15 +31,32 @@ class pfb_arb_resampler_ccf(gr.hier_block2):
     streams. This block is provided to be consistent with the interface to the
     other PFB block.
     '''
     streams. This block is provided to be consistent with the interface to the
     other PFB block.
     '''

-    def __init__(self, rate, taps, flt_size=32):
+    def __init__(self, rate, taps=None, flt_size=32, atten=100):

        gr.hier_block2.__init__(self, "pfb_arb_resampler_ccf",
                                gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
                                gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature
         
         self._rate = rate
        gr.hier_block2.__init__(self, "pfb_arb_resampler_ccf",
                                gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
                                gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature
         
         self._rate = rate

-        self._taps = taps

         self._size = flt_size
 
         self._size = flt_size
 

+        if taps is not None:
+            self._taps = taps
+        else:
+            # Create a filter that covers the full bandwidth of the input signal
+            bw = 0.4
+            tb = 0.2
+            ripple = 0.1
+            #self._taps = gr.firdes.low_pass_2(self._size, self._size, bw, tb, atten)
+            made = False
+            while not made:
+                try:
+                    self._taps = optfir.low_pass(self._size, self._size, bw, bw+tb, ripple, atten)
+                    made = True
+                except RuntimeError:
+                    ripple += 0.01
+                    made = False
+                    print("Warning: set ripple to %.4f dB. If this is a problem, adjust the attenuation or create your own filter taps." % (ripple))
+

         self.pfb = gr.pfb_arb_resampler_ccf(self._rate, self._taps, self._size)
 
         self.connect(self, self.pfb)
         self.pfb = gr.pfb_arb_resampler_ccf(self._rate, self._taps, self._size)
 
         self.connect(self, self.pfb)