Implement QPSK TX - RX with USRP hardware

And fix some small issues in QPSK simulation.

The signal flow graph was tested with a coaxial cable, as well as with
an 2.4 GHz antenna. The constellation diagram looked OK, but the sent
data (bytes of lena512color.tiff) were neither decoded nor tested. That
is because we need to synchronize data frames with a header thing or
something like that (which is still not implemented yet).

1 files changed, 13 insertions, 12 deletions

diff --git a/simulation/QPSK/qpks.py b/simulation/QPSK/qpks.py
index e436356..11e7004 100755
--- a/simulation/QPSK/qpks.py
+++ b/simulation/QPSK/qpks.py
@@ -77,16 +77,16 @@ class qpks(gr.top_block, Qt.QWidget):
         ##################################################
         self.sps = sps = 4
         self.nfilts = nfilts = 32
+        self.excess_bw = excess_bw = 350e-3
         self.timing_loop_bw = timing_loop_bw = 2 * 3.141592653589793 / 100
         self.time_offset = time_offset = 1.0
         self.samp_rate = samp_rate = 32000
-        self.rrc_taps = rrc_taps = firdes.root_raised_cosine(nfilts, nfilts, 1.0/float(sps), 0.35, 45*nfilts)
+        self.rrc_taps = rrc_taps = firdes.root_raised_cosine(nfilts, nfilts, 1.0/float(sps), excess_bw, 45*nfilts)
         self.qpsk_const = qpsk_const = digital.constellation_rect([0.707+0.707j, -0.707+0.707j, -0.707-0.707j, 0.707-0.707j], [0, 1, 3, 2],
         4, 2, 2, 1, 1).base()
         self.phase_bw = phase_bw = 2 * 3.141592653589793 / 100
         self.noise_volt = noise_volt = 0.0001
         self.freq_offset = freq_offset = 0
-        self.excess_bw = excess_bw = 350e-3
         self.eq_ntaps = eq_ntaps = 15
         self.eq_mod = eq_mod = 1
         self.eq_gain = eq_gain = .01
@@ -179,14 +179,14 @@ class qpks(gr.top_block, Qt.QWidget):
 
         self.qtgui_time_sink_x_0.enable_tags(True)
         self.qtgui_time_sink_x_0.set_trigger_mode(qtgui.TRIG_MODE_FREE, qtgui.TRIG_SLOPE_POS, 0.0, 0, 0, "")
-        self.qtgui_time_sink_x_0.enable_autoscale(True)
+        self.qtgui_time_sink_x_0.enable_autoscale(False)
         self.qtgui_time_sink_x_0.enable_grid(False)
         self.qtgui_time_sink_x_0.enable_axis_labels(True)
         self.qtgui_time_sink_x_0.enable_control_panel(False)
         self.qtgui_time_sink_x_0.enable_stem_plot(False)
 
 
-        labels = ['Signal 1', 'Signal 2', 'Signal 3', 'Signal 4', 'Signal 5',
+        labels = ['Received', 'Sent', 'Signal 3', 'Signal 4', 'Signal 5',
             'Signal 6', 'Signal 7', 'Signal 8', 'Signal 9', 'Signal 10']
         widths = [1, 1, 1, 1, 1,
             1, 1, 1, 1, 1]
@@ -504,14 +504,21 @@ class qpks(gr.top_block, Qt.QWidget):
 
     def set_sps(self, sps):
         self.sps = sps
-        self.set_rrc_taps(firdes.root_raised_cosine(self.nfilts, self.nfilts, 1.0/float(self.sps), 0.35, 45*self.nfilts))
+        self.set_rrc_taps(firdes.root_raised_cosine(self.nfilts, self.nfilts, 1.0/float(self.sps), self.excess_bw, 45*self.nfilts))
 
     def get_nfilts(self):
         return self.nfilts
 
     def set_nfilts(self, nfilts):
         self.nfilts = nfilts
-        self.set_rrc_taps(firdes.root_raised_cosine(self.nfilts, self.nfilts, 1.0/float(self.sps), 0.35, 45*self.nfilts))
+        self.set_rrc_taps(firdes.root_raised_cosine(self.nfilts, self.nfilts, 1.0/float(self.sps), self.excess_bw, 45*self.nfilts))
+
+    def get_excess_bw(self):
+        return self.excess_bw
+
+    def set_excess_bw(self, excess_bw):
+        self.excess_bw = excess_bw
+        self.set_rrc_taps(firdes.root_raised_cosine(self.nfilts, self.nfilts, 1.0/float(self.sps), self.excess_bw, 45*self.nfilts))
 
     def get_timing_loop_bw(self):
         return self.timing_loop_bw
@@ -570,12 +577,6 @@ class qpks(gr.top_block, Qt.QWidget):
         self.freq_offset = freq_offset
         self.channels_channel_model_0.set_frequency_offset(self.freq_offset)
 
-    def get_excess_bw(self):
-        return self.excess_bw
-
-    def set_excess_bw(self, excess_bw):
-        self.excess_bw = excess_bw
-
     def get_eq_ntaps(self):
         return self.eq_ntaps