1 files changed, 64 insertions, 51 deletions
diff --git a/gr-trellis/docs/test_viterbi_equalization1.py b/gr-trellis/docs/test_viterbi_equalization1.py
index 1302712d98..88b425ac8b 100644
--- a/gr-trellis/docs/test_viterbi_equalization1.py
+++ b/gr-trellis/docs/test_viterbi_equalization1.py
@@ -15,94 +15,107 @@ except ImportError:
     sys.stderr.write("Error: Program requires gr-analog.\n")
     sys.exit(1)
 
-def run_test (f,Kb,bitspersymbol,K,channel,modulation,dimensionality,tot_constellation,N0,seed):
-    tb = gr.top_block ()
+
+def run_test(f, Kb, bitspersymbol, K, channel, modulation, dimensionality, tot_constellation, N0, seed):
+    tb = gr.top_block()
     L = len(channel)
 
     # TX
     # this for loop is TOO slow in python!!!
-    packet = [0]*(K+2*L)
+    packet = [0] * (K + 2 * L)
     random.seed(seed)
     for i in range(len(packet)):
-        packet[i] = random.randint(0, 2**bitspersymbol - 1) # random symbols
-    for i in range(L): # first/last L symbols set to 0
+        packet[i] = random.randint(0, 2**bitspersymbol - 1)  # random symbols
+    for i in range(L):  # first/last L symbols set to 0
         packet[i] = 0
-        packet[len(packet)-i-1] = 0
-    src = blocks.vector_source_s(packet,False)
-    mod = digital.chunks_to_symbols_sf(modulation[1],modulation[0])
+        packet[len(packet) - i - 1] = 0
+    src = blocks.vector_source_s(packet, False)
+    mod = digital.chunks_to_symbols_sf(modulation[1], modulation[0])
 
     # CHANNEL
-    isi = filter.fir_filter_fff(1,channel)
+    isi = filter.fir_filter_fff(1, channel)
     add = blocks.add_ff()
-    noise = analog.noise_source_f(analog.GR_GAUSSIAN,math.sqrt(N0 / 2),seed)
+    noise = analog.noise_source_f(analog.GR_GAUSSIAN, math.sqrt(N0 / 2), seed)
 
     # RX
-    skip = blocks.skiphead(gr.sizeof_float, L) # skip the first L samples since you know they are coming from the L zero symbols
-    #metrics = trellis.metrics_f(f.O(),dimensionality,tot_constellation,digital.TRELLIS_EUCLIDEAN) # data preprocessing to generate metrics for Viterbi
-    #va = trellis.viterbi_s(f,K+L,0,0) # Put -1 if the Initial/Final states are not set.
-    va = trellis.viterbi_combined_s(f,K+L,0,0,dimensionality,tot_constellation,digital.TRELLIS_EUCLIDEAN) # using viterbi_combined_s instead of metrics_f/viterbi_s allows larger packet lengths because metrics_f is complaining for not being able to allocate large buffers. This is due to the large f.O() in this application...
+    # skip the first L samples since you know they are coming from the L zero symbols
+    skip = blocks.skiphead(gr.sizeof_float, L)
+    # metrics = trellis.metrics_f(f.O(),dimensionality,tot_constellation,digital.TRELLIS_EUCLIDEAN) # data preprocessing to generate metrics for Viterbi
+    # va = trellis.viterbi_s(f,K+L,0,0) # Put -1 if the Initial/Final states are not set.
+    # using viterbi_combined_s instead of metrics_f/viterbi_s allows larger packet lengths because metrics_f is complaining for not being able to allocate large buffers. This is due to the large f.O() in this application...
+    va = trellis.viterbi_combined_s(
+        f, K + L, 0, 0, dimensionality, tot_constellation, digital.TRELLIS_EUCLIDEAN)
     dst = blocks.vector_sink_s()
 
-    tb.connect (src,mod)
-    tb.connect (mod,isi,(add,0))
-    tb.connect (noise,(add,1))
+    tb.connect(src, mod)
+    tb.connect(mod, isi, (add, 0))
+    tb.connect(noise, (add, 1))
     #tb.connect (add,metrics)
     #tb.connect (metrics,va,dst)
-    tb.connect (add,skip,va,dst)
+    tb.connect(add, skip, va, dst)
 
     tb.run()
 
     data = dst.data()
     ntotal = len(data) - L
-    nright=0
+    nright = 0
     for i in range(ntotal):
-        if packet[i+L]==data[i]:
-            nright=nright+1
-        #else:
-            #print "Error in ", i
+        if packet[i + L] == data[i]:
+            nright = nright + 1
+        # else:
+            # print "Error in ", i
 
-    return (ntotal,ntotal-nright)
+    return (ntotal, ntotal - nright)
 
 
 def main(args):
-    nargs = len (args)
+    nargs = len(args)
     if nargs == 2:
-        esn0_db=float(args[0])
-        rep=int(args[1])
+        esn0_db = float(args[0])
+        rep = int(args[1])
     else:
-        sys.stderr.write ('usage: test_viterbi_equalization1.py Es/No_db  repetitions\n')
-        sys.exit (1)
+        sys.stderr.write(
+            'usage: test_viterbi_equalization1.py Es/No_db  repetitions\n')
+        sys.exit(1)
 
     # system parameters
-    Kb=2048  # packet size in bits
-    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
-    f=trellis.fsm(len(modulation[1]),len(channel)) # generate the FSM automatically
-    bitspersymbol = int(round(math.log(f.I()) / math.log(2))) # bits per FSM input symbol
-    K=Kb / bitspersymbol # packet size in trellis steps
-
-    tot_channel = fsm_utils.make_isi_lookup(modulation,channel,True) # generate the lookup table (normalize energy to 1)
+    Kb = 2048  # packet size in bits
+    modulation = fsm_utils.pam4  # see fsm_utlis.py for available predefined modulations
+    # see fsm_utlis.py for available predefined test channels
+    channel = fsm_utils.c_channel
+    # generate the FSM automatically
+    f = trellis.fsm(len(modulation[1]), len(channel))
+    # bits per FSM input symbol
+    bitspersymbol = int(round(math.log(f.I()) / math.log(2)))
+    K = Kb / bitspersymbol  # packet size in trellis steps
+
+    # generate the lookup table (normalize energy to 1)
+    tot_channel = fsm_utils.make_isi_lookup(modulation, channel, True)
     dimensionality = tot_channel[0]
     tot_constellation = tot_channel[1]
-    N0=pow(10.0,-esn0_db / 10.0); # noise variance
+    N0 = pow(10.0, -esn0_db / 10.0)  # noise variance
     if len(tot_constellation) / dimensionality != f.O():
-        sys.stderr.write ('Incompatible FSM output cardinality and lookup table size.\n')
-        sys.exit (1)
+        sys.stderr.write(
+            'Incompatible FSM output cardinality and lookup table size.\n')
+        sys.exit(1)
 
-    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
+    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(f,Kb,bitspersymbol,K,channel,modulation,dimensionality,tot_constellation,N0,-int(666+i)) # run experiment with different seed to get different data and noise realizations
-        tot_s=tot_s+s
-        terr_s=terr_s+e
-        terr_p=terr_p+(terr_s!=0)
-        if ((i+1)%100==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))
+        (s, e) = run_test(f, Kb, bitspersymbol, K, channel, modulation, dimensionality, tot_constellation,
+                          N0, -int(666 + i))  # run experiment with different seed to get different data and noise realizations
+        tot_s = tot_s + s
+        terr_s = terr_s + e
+        terr_p = terr_p + (terr_s != 0)
+        if ((i + 1) % 100 == 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 symbol) error rate
-    print(rep,terr_p, '%.2e' % ((1.0*terr_p) / (i+1)),tot_s,terr_s, '%.2e' % ((1.0*terr_s) / tot_s))
+    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:])
+    main(sys.argv[1:])