1 files changed, 63 insertions, 0 deletions
diff --git a/gssm/src/python/gssm_usrp.py b/gssm/src/python/gssm_usrp.py
new file mode 100755
index 0000000..f8ea583
--- /dev/null
+++ b/gssm/src/python/gssm_usrp.py
@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+
+# $Id: gssm_usrp.py,v 1.2 2007-07-07 16:31:44 jl Exp $
+
+from gnuradio import gr, usrp, db_dbs_rx, blks
+from gnuradio.blksimpl import gmsk
+from usrpm import usrp_dbid
+import gssm
+import sys
+
+# constant
+gsm_rate	= 1625000.0 / 6.0
+
+# script constant
+decim		= 112
+gain		= 70
+
+# bts channel
+c0		= 875.4e6
+
+# experimental constant
+default_usrp_offset = 12e3
+
+class gssm_flow_graph(gr.flow_graph):
+	def __init__(self, usrp_offset):
+		gr.flow_graph.__init__(self)
+
+		u = usrp.source_c(decim_rate = decim)
+		s = usrp.pick_subdev(u, (usrp_dbid.DBS_RX,))
+		u.set_mux(usrp.determine_rx_mux_value(u, s))
+		subdev = usrp.selected_subdev(u, s)
+
+		if subdev.dbid() != usrp_dbid.DBS_RX:
+			raise Exception('dbs daughterboard not detected!')
+
+		subdev.set_gain(gain)
+
+		sps = u.adc_freq() / u.decim_rate()
+		if sps < 2 * gsm_rate:
+			raise Exception('sample rate too low')
+
+		u.tune(0, subdev, c0 + usrp_offset)
+
+		xcf = 150e3
+		xtw = 50e3
+		xt = gr.firdes.low_pass(1.0, sps, xcf, xtw,
+		   gr.firdes.WIN_HAMMING)
+		xf = gr.fir_filter_ccf(1, xt)
+
+		g = gssm.sink(sps)
+
+		self.connect(u, xf, g)
+
+def main():
+	if len(sys.argv) == 2:
+		uo = float(sys.argv[1])
+	else:
+		uo = default_usrp_offset
+	g = gssm_flow_graph(uo)
+	g.run()
+
+if __name__ == '__main__':
+	main()