1 files changed, 103 insertions, 0 deletions
diff --git a/gnuradio-examples/python/digital/limbo/qpsk_usrp_tester.py b/gnuradio-examples/python/digital/limbo/qpsk_usrp_tester.py
new file mode 100644
index 0000000000..bf7698a2b2
--- /dev/null
+++ b/gnuradio-examples/python/digital/limbo/qpsk_usrp_tester.py
@@ -0,0 +1,103 @@
+#!/usr/bin/env python
+
+import random
+from gnuradio import gr, gru, usrp
+
+default_access_code = '\xAC\xDD\xA4\xE2\xF2\x8C\x20\xFC'
+
+def string_to_1_0_list(s):
+    r = []
+    for ch in s:
+        x = ord(ch)
+        for i in range(8):
+            t = (x >> i) & 0x1
+            r.append(t)
+
+    return r
+
+def to_1_0_string(L):
+    return ''.join(map(lambda x: chr(x + ord('0')), L))
+
+code = string_to_1_0_list(default_access_code)
+
+access_code = to_1_0_string(code)
+
+def main():
+
+    fg = gr.flow_graph()
+    f_rf = 5e6
+    fs = 400e3
+    sr = 100e3
+    alpha = 0.5
+    M = 4
+    k = int(gru.log2(M))
+    
+    # Source
+    src = usrp.source_c ()
+    adc_rate = src.adc_rate()
+    usrp_decim = int(adc_rate / fs)
+    src.set_decim_rate(usrp_decim)
+        
+    subdev_spec = usrp.pick_rx_subdevice(src)
+    subdev = usrp.selected_subdev(src, subdev_spec)
+    print "Using RX d'board %s" % (subdev.side_and_name(),)
+    src.set_mux(usrp.determine_rx_mux_value(src, subdev_spec))
+    src.tune(0, subdev, f_rf)
+        
+    g = subdev.gain_range()
+    subdev.set_gain(g[1])
+    subdev.set_auto_tr(True)
+        
+    print "USRP Decimation Rate = %d" % usrp_decim
+    print "RF Frequency = %d" % f_rf
+
+    agc = gr.multiply_const_cc(0.0025)
+        
+    # Downconverter
+    costas_alpha=0.005
+    beta = costas_alpha*costas_alpha*0.25
+    sync_loop = gr.costas_loop_cc(costas_alpha, beta, 0.05, -0.05, 0)
+
+    # Stage 2
+#    fs2 = 200e3
+#    D = int(fs / fs2)
+#    decimator = gr.keep_one_in_n(gr.sizeof_gr_complex, D)
+#    print "D = %d\nAfter decimator fs = %f" % (D, fs2)
+
+    # Demodulator
+    taps = gr.firdes.root_raised_cosine(1, fs, sr, alpha, 45)
+    rrc  = gr.fir_filter_ccf(1, taps)
+    
+    # Sampler
+    mu = 0.01
+    omega = 4.3
+    gain_mu = 0.05
+    gain_omega = 0.25*gain_mu*gain_mu
+    omega_rel_limit = 0.5
+    clock_sync = gr.clock_recovery_mm_cc(omega, gain_omega, mu,
+                                         gain_mu, omega_rel_limit)
+    clock_sync.set_verbose(False)
+
+    diff_phasor = gr.diff_phasor_cc()
+
+    threshold = 12
+    constellation = (1+0j, 0+1j, -1+0j, 0-1j)
+    slicer = gr.constellation_decoder_cb((constellation), (0,1,2,3))
+    unpack = gr.unpack_k_bits_bb(k)
+    access = gr.correlate_access_code_bb(access_code,threshold)
+
+    test = gr.file_sink(gr.sizeof_gr_complex, 'test.dat')
+    sink = gr.file_sink(gr.sizeof_char, 'output.dat')
+
+    fg.connect(src, agc, sync_loop, rrc, clock_sync)
+    fg.connect(clock_sync, diff_phasor, slicer, unpack, access, sink)
+
+    fg.connect(slicer, gr.file_sink(gr.sizeof_char, 'chunks.dat'))
+    fg.connect(unpack, gr.file_sink(gr.sizeof_char, 'unpack.dat'))
+    fg.connect(clock_sync, gr.file_sink(gr.sizeof_gr_complex, 'phasor.dat'))
+
+    fg.start()
+    fg.wait()
+
+if __name__ == "__main__":
+    main()