--- /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 fsm_utils
+
+
+def make_rx(tb,fo,fi,dimensionality,tot_constellation,K,interleaver,IT,Es,N0,type):
+ metrics_in = trellis.metrics_f(fi.O(),dimensionality,tot_constellation,trellis.TRELLIS_EUCLIDEAN) # data preprocessing to generate metrics for innner SISO
+ scale = gr.multiply_const_ff(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_f(fi,K,0,-1,True,False,type) )
+ 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 (metrics_in,scale)
+ tb.connect (scale,(siso_in[0],1))
+
+ # connect the rest
+ for it in range(IT):
+ if it < IT-1:
+ tb.connect (metrics_in,(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 (metrics_in,siso_out[IT-1])
+
+
+def run_test (fo,fi,interleaver,Kb,bitspersymbol,K,dimensionality,tot_constellation,Es,N0,IT,seed):
+ tb = gr.top_block ()
+
+ # TX
+ src = gr.lfsr_32k_source_s()
+ src_head = gr.head (gr.sizeof_short,Kb/16) # packet size in shorts
+ s2fsmi = gr.packed_to_unpacked_ss(bitspersymbol,gr.GR_MSB_FIRST) # unpack shorts to symbols compatible with the iouter FSM input cardinality
+ enc_out = trellis.encoder_ss(fo,0) # initial state = 0
+ inter = trellis.permutation(interleaver.K(),interleaver.INTER(),1,gr.sizeof_short)
+ enc_in = trellis.encoder_ss(fi,0) # initial state = 0
+ # essentially here we implement the combination of modulation and channel as a memoryless modulation (the memory induced by the channel is hidden in the innner FSM)
+ mod = gr.chunks_to_symbols_sf(tot_constellation,dimensionality)
+
+ # 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)
+ fsmi2s = gr.unpacked_to_packed_ss(bitspersymbol,gr.GR_MSB_FIRST) # pack FSM input symbols to shorts
+ dst = gr.check_lfsr_32k_s();
+
+ tb.connect (src,src_head,s2fsmi,enc_out,inter,enc_in,mod)
+ tb.connect (mod,(add,0))
+ tb.connect (noise,(add,1))
+ tb.connect (add,head)
+ tb.connect (tail,fsmi2s,dst)
+
+ tb.run()
+
+ ntotal = dst.ntotal ()
+ nright = dst.nright ()
+ runlength = dst.runlength ()
+ #print ntotal,nright,runlength
+
+ 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
+ print 'size = ',K
+ 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]
+ tot_constellation = tot_channel[1]
+ if len(tot_constellation)/dimensionality != fi.O():
+ sys.stderr.write ('Incompatible FSM output cardinality and lookup table size.\n')
+ sys.exit (1)
+ N0=pow(10.0,-esn0_db/10.0); # noise variance
+ 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,dimensionality,tot_constellation,1,N0,IT,-long(666+i)) # run experiment with different seed to get different noise realizations
+ print s
+ 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