--- /dev/null
+#!/usr/bin/env python
+
+from gnuradio import gr
+from gnuradio import audio
+from gnuradio import trellis
+from gnuradio import eng_notation
+import math
+import sys
+import random
+import fsm_utils
+
+def make_rx(tb,fo,fi,dimensionality,tot_constellation,K,interleaver,IT,Es,N0,type):
+ scale = gr.multiply_const_ff(math.sqrt(1.0/N0))
+ gnd = gr.vector_source_f([0],True);
+
+ inter=[]
+ deinter=[]
+ siso_in=[]
+ siso_out=[]
+
+ # generate all blocks
+ for it in range(IT):
+ inter.append( trellis.permutation(interleaver.K(),interleaver.INTER(),fi.I(),gr.sizeof_float) )
+ siso_in.append( trellis.siso_combined_f(fi,K,0,-1,True,False,type,dimensionality,tot_constellation,trellis.TRELLIS_EUCLIDEAN) )
+ deinter.append( trellis.permutation(interleaver.K(),interleaver.DEINTER(),fi.I(),gr.sizeof_float) )
+ if it < IT-1:
+ siso_out.append( trellis.siso_f(fo,K,0,-1,False,True,type) )
+ else:
+ siso_out.append( trellis.viterbi_s(fo,K,0,-1) ) # no soft outputs needed
+
+ # connect first stage
+ tb.connect (gnd,inter[0])
+ tb.connect (scale,(siso_in[0],1))
+
+ # connect the rest
+ for it in range(IT):
+ if it < IT-1:
+ tb.connect (scale,(siso_in[it+1],1))
+ tb.connect (siso_in[it],deinter[it],(siso_out[it],1))
+ tb.connect (gnd,(siso_out[it],0))
+ tb.connect (siso_out[it],inter[it+1])
+ tb.connect (inter[it],(siso_in[it],0))
+ else:
+ tb.connect (siso_in[it],deinter[it],siso_out[it])
+ tb.connect (inter[it],(siso_in[it],0))
+
+ return (scale,siso_out[IT-1])
+
+
+def run_test (fo,fi,interleaver,Kb,bitspersymbol,K,channel,modulation,dimensionality,tot_constellation,Es,N0,IT,seed):
+ tb = gr.top_block ()
+ L = len(channel)
+
+ # TX
+ # this for loop is TOO slow in python!!!
+ packet = [0]*(K)
+ random.seed(seed)
+ for i in range(len(packet)):
+ packet[i] = random.randint(0, 2**bitspersymbol - 1) # random symbols
+ src = gr.vector_source_s(packet,False)
+ enc_out = trellis.encoder_ss(fo,0) # initial state = 0
+ inter = trellis.permutation(interleaver.K(),interleaver.INTER(),1,gr.sizeof_short)
+ mod = gr.chunks_to_symbols_sf(modulation[1],modulation[0])
+
+ # CHANNEL
+ isi = gr.fir_filter_fff(1,channel)
+ add = gr.add_ff()
+ noise = gr.noise_source_f(gr.GR_GAUSSIAN,math.sqrt(N0/2),seed)
+
+ # RX
+ (head,tail) = make_rx(tb,fo,fi,dimensionality,tot_constellation,K,interleaver,IT,Es,N0,trellis.TRELLIS_MIN_SUM)
+ dst = gr.vector_sink_s();
+
+ tb.connect (src,enc_out,inter,mod)
+ tb.connect (mod,isi,(add,0))
+ tb.connect (noise,(add,1))
+ tb.connect (add,head)
+ tb.connect (tail,dst)
+
+ tb.run()
+
+ data = dst.data()
+ ntotal = len(data)
+ nright=0
+ for i in range(ntotal):
+ if packet[i]==data[i]:
+ nright=nright+1
+ #else:
+ #print "Error in ", i
+
+ return (ntotal,ntotal-nright)
+
+
+
+
+def main(args):
+ nargs = len (args)
+ if nargs == 3:
+ fname_out=args[0]
+ esn0_db=float(args[1])
+ rep=int(args[2])
+ else:
+ sys.stderr.write ('usage: test_turbo_equalization.py fsm_name_out Es/No_db repetitions\n')
+ sys.exit (1)
+
+ # system parameters
+ Kb=64*16 # packet size in bits (multiple of 16)
+ modulation = fsm_utils.pam4 # see fsm_utlis.py for available predefined modulations
+ channel = fsm_utils.c_channel # see fsm_utlis.py for available predefined test channels
+ fo=trellis.fsm(fname_out) # get the outer FSM specification from a file
+ fi=trellis.fsm(len(modulation[1]),len(channel)) # generate the FSM automatically
+ if fo.O() != fi.I():
+ sys.stderr.write ('Incompatible cardinality between outer and inner FSM.\n')
+ sys.exit (1)
+ bitspersymbol = int(round(math.log(fo.I())/math.log(2))) # bits per FSM input symbol
+ K=Kb/bitspersymbol # packet size in trellis steps
+ interleaver=trellis.interleaver(K,666) # construct a random interleaver
+ tot_channel = fsm_utils.make_isi_lookup(modulation,channel,True) # generate the lookup table (normalize energy to 1)
+ dimensionality = tot_channel[0]
+ N0=pow(10.0,-esn0_db/10.0); # noise variance
+ tot_constellation =[0]*len(tot_channel[1])
+ for i in range(len(tot_channel[1])):
+ tot_constellation[i] = tot_channel[1][i] * math.sqrt(1.0/N0)
+ if len(tot_constellation)/dimensionality != fi.O():
+ sys.stderr.write ('Incompatible FSM output cardinality and lookup table size.\n')
+ sys.exit (1)
+ IT = 3 # number of turbo iterations
+
+ tot_s=0 # total number of transmitted shorts
+ terr_s=0 # total number of shorts in error
+ terr_p=0 # total number of packets in error
+
+ for i in range(rep):
+ (s,e)=run_test(fo,fi,interleaver,Kb,bitspersymbol,K,channel,modulation,dimensionality,tot_constellation,1,N0,IT,-long(666+i)) # run experiment with different seed to get different noise realizations
+ tot_s=tot_s+s
+ terr_s=terr_s+e
+ terr_p=terr_p+(terr_s!=0)
+ if ((i+1)%10==0) : # display progress
+ print i+1,terr_p, '%.2e' % ((1.0*terr_p)/(i+1)),tot_s,terr_s, '%.2e' % ((1.0*terr_s)/tot_s)
+ # estimate of the (short or bit) error rate
+ print rep,terr_p, '%.2e' % ((1.0*terr_p)/(i+1)),tot_s,terr_s, '%.2e' % ((1.0*terr_s)/tot_s)
+
+
+
+if __name__ == '__main__':
+ main (sys.argv[1:])
+
projects / debian / gnuradio / blobdiff