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Diffstat (limited to 'gr-trellis/docs/test_tcm.py.xml')
| -rw-r--r-- | gr-trellis/docs/test_tcm.py.xml | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/gr-trellis/docs/test_tcm.py.xml b/gr-trellis/docs/test_tcm.py.xml new file mode 100644 index 000000000..77009b585 --- /dev/null +++ b/gr-trellis/docs/test_tcm.py.xml @@ -0,0 +1,95 @@ +<?xml version="1.0" encoding="ISO-8859-1"?> +<programlisting> + 1 #!/usr/bin/env python + 2 + 3 from gnuradio import gr + 4 from gnuradio import audio + 5 from gnuradio import trellis, digital, analog, blocks + 6 from gnuradio import eng_notation + 7 import math + 8 import sys + 9 import random + 10 import fsm_utils + 11 + 12 def run_test (f,Kb,bitspersymbol,K,dimensionality,constellation,N0,seed): + 13 tb = gr.top_block () + 14 + 15 # TX + 16 src = blocks.lfsr_32k_source_s() + 17 src_head = blocks.head (gr.sizeof_short,Kb/16) # packet size in shorts + 18 s2fsmi = blocks.packed_to_unpacked_ss(bitspersymbol,gr.GR_MSB_FIRST) # unpack shorts to symbols compatible with the FSM input cardinality + 19 enc = trellis.encoder_ss(f,0) # initial state = 0 + 20 mod = digital.chunks_to_symbols_sf(constellation,dimensionality) + 21 + 22 # CHANNEL + 23 add = blocks.add_ff() + 24 noise = analog.noise_source_f(analog.GR_GAUSSIAN,math.sqrt(N0/2),seed) + 25 + 26 # RX + 27 metrics = trellis.metrics_f(f.O(),dimensionality,constellation,trellis.TRELLIS_EUCLIDEAN) # data preprocessing to generate metrics for Viterbi + 28 va = trellis.viterbi_s(f,K,0,-1) # Put -1 if the Initial/Final states are not set. + 29 fsmi2s = blocks.unpacked_to_packed_ss(bitspersymbol,gr.GR_MSB_FIRST) # pack FSM input symbols to shorts + 30 dst = blocks.check_lfsr_32k_s(); + 31 + 32 tb.connect (src,src_head,s2fsmi,enc,mod) + 33 tb.connect (mod,(add,0)) + 34 tb.connect (noise,(add,1)) + 35 tb.connect (add,metrics) + 36 tb.connect (metrics,va,fsmi2s,dst) + 37 + 38 tb.run() + 39 + 40 # A bit of cheating: run the program once and print the + 41 # final encoder state. + 42 # Then put it as the last argument in the viterbi block + 43 #print "final state = " , enc.ST() + 44 + 45 ntotal = dst.ntotal () + 46 nright = dst.nright () + 47 runlength = dst.runlength () + 48 return (ntotal,ntotal-nright) + 49 + 50 + 51 def main(args): + 52 nargs = len (args) + 53 if nargs == 3: + 54 fname=args[0] + 55 esn0_db=float(args[1]) # Es/No in dB + 56 rep=int(args[2]) # number of times the experiment is run to collect enough errors + 57 else: + 58 sys.stderr.write ('usage: test_tcm.py fsm_fname Es/No_db repetitions\n') + 59 sys.exit (1) + 60 + 61 # system parameters + 62 f=trellis.fsm(fname) # get the FSM specification from a file + 63 Kb=1024*16 # packet size in bits (make it multiple of 16 so it can be packed in a short) + 64 bitspersymbol = int(round(math.log(f.I())/math.log(2))) # bits per FSM input symbol + 65 K=Kb/bitspersymbol # packet size in trellis steps + 66 modulation = fsm_utils.psk4 # see fsm_utlis.py for available predefined modulations + 67 dimensionality = modulation[0] + 68 constellation = modulation[1] + 69 if len(constellation)/dimensionality != f.O(): + 70 sys.stderr.write ('Incompatible FSM output cardinality and modulation size.\n') + 71 sys.exit (1) + 72 # calculate average symbol energy + 73 Es = 0 + 74 for i in range(len(constellation)): + 75 Es = Es + constellation[i]**2 + 76 Es = Es / (len(constellation)/dimensionality) + 77 N0=Es/pow(10.0,esn0_db/10.0); # noise variance + 78 + 79 tot_s=0 + 80 terr_s=0 + 81 for i in range(rep): + 82 (s,e)=run_test(f,Kb,bitspersymbol,K,dimensionality,constellation,N0,-long(666+i)) # run experiment with different seed to get different noise realizations + 83 tot_s=tot_s+s + 84 terr_s=terr_s+e + 85 if (i%100==0): + 86 print i,s,e,tot_s,terr_s, '%e' % ((1.0*terr_s)/tot_s) + 87 # estimate of the (short) error rate + 88 print tot_s,terr_s, '%e' % ((1.0*terr_s)/tot_s) + 89 + 90 + 91 if __name__ == '__main__': + 92 main (sys.argv[1:]) +</programlisting> |