Several enhancements to gr-trellis and gnuradio-examples/python/channel-coding:

-Added fsm constructor for generating FSM directly from the
generator matrix of binary convolutional codes.
-Added functionality to fsm class to compute the best way to
go from any state to any other state (useful for termination)
-Added soft-in-soft-out (SISO) block for turbo processing
-Added turbo decoding examples



git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@3322 221aa14e-8319-0410-a670-987f0aec2ac5

22 files changed, 616 insertions, 245 deletions

diff --git a/gnuradio-examples/python/channel-coding/README b/gnuradio-examples/python/channel-coding/README
index abfceb429..2be8c6ba1 100644
--- a/gnuradio-examples/python/channel-coding/README
+++ b/gnuradio-examples/python/channel-coding/README
@@ -8,26 +8,39 @@ fsm_files is a directory with some FSM definitions
 
 If you just want to see what these programs do, run each of the following:
 
-./test_tcm.py fsm_files/awgn1o2_4.fsm 10.0 1000
-./test_tcm1.py fsm_files/awgn1o2_4.fsm 10.0 1000
-./test_tcm_combined.py fsm_files/awgn1o2_4.fsm 10.0 1000
-./test_tcm_parallel.py fsm_files/awgn1o2_4.fsm 10.0 1000
-./test_sccc_hard.py fsm_files/awgn1o2_4.fsm fsm_files/awgn1o2_4.fsm 10.0 1000
+./test_tcm.py  fsm_files/awgn1o2_4.fsm 6.0 1000
+./test_tcm1.py fsm_files/awgn1o2_4.fsm 6.0 1000
+./test_tcm2.py 6.0 1000
+./test_tcm_combined.py fsm_files/awgn1o2_4.fsm 6.0 1000
+./test_tcm_parallel.py fsm_files/awgn1o2_4.fsm 6.0 1000
+
+./test_sccc_hard.py  fsm_files/awgn1o2_4.fsm fsm_files/awgn1o2_4_msb.fsm 10.0 100
+./test_sccc_soft.py  fsm_files/awgn1o2_4.fsm fsm_files/awgn1o2_4_msb.fsm  8.0 100
+./test_sccc_turbo.py fsm_files/awgn1o2_4.fsm fsm_files/awgn1o2_4_msb.fsm  5.0 100
 
 In your terminal you will see something like this:
 
-[anastas@ernesto channel-coding]$ ./test_tcm.py fsm_files/awgn1o2_4.fsm 6.0 1000
-100 1024 1 103424 10 9.668936e-05
-200 1024 1 205824 21 1.020289e-04
-300 1024 0 308224 40 1.297757e-04
-400 1024 0 410624 1074 2.615531e-03
-500 1024 0 513024 1081 2.107114e-03
-600 1024 0 615424 1090 1.771137e-03
-700 1024 0 717824 1097 1.528230e-03
-800 1024 0 820224 1107 1.349631e-03
-900 1024 0 922624 1120 1.213929e-03
-1024000 1129 1.102539e-03
-
-1.102539e-03 is the error rate estimates by sending 1000 packets of
-1024x16 bits each using an 1/2 4-state convolutional code and QPSK
+$ ./test_tcm.py fsm_files/awgn1o2_4.fsm 6.0 1000
+100 98 9.80e-01 102400 9 8.79e-05
+200 198 9.90e-01 204800 20 9.77e-05
+300 298 9.93e-01 307200 40 1.30e-04
+400 398 9.95e-01 409600 1074 2.62e-03
+500 498 9.96e-01 512000 1081 2.11e-03
+600 598 9.97e-01 614400 1090 1.77e-03
+700 698 9.97e-01 716800 1097 1.53e-03
+800 798 9.98e-01 819200 1107 1.35e-03
+900 898 9.98e-01 921600 1120 1.22e-03
+1000 998 9.98e-01 1024000 1129 1.10e-03
+1000 998 9.98e-01 1024000 1129 1.10e-03
+
+which gives you information about the:
+number of transmitted packets
+number of packets in error
+iestimated packet error rate
+number of transmitted shorts
+number of shorts in error
+estimated (short) error rate 
+
+1.10e-03 is the error rate estimate by sending 1000 packets of
+1024 shorts each, using an 1/2 4-state convolutional code and QPSK
 modulation through an AWGN with Es/N0 = 6.0 dB
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_128.fsm b/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_128.fsm
index 9c14d82f3..bb79c59da 100644
--- a/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_128.fsm
+++ b/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_128.fsm
@@ -260,5 +260,6 @@
 
 
 
-GM1o2_128=[1+D^3+D^4+D^5+D^6+D^7   1+D+D^2+D^5+D^7]
-         =[249 167]
+GM1o2_128=[1+D+D^2+D^5+D^7	1+D^3+D^4+D^5+D^6+D^7]
+         =[11100101		10011111]
+         =[229			159]
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_16.fsm b/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_16.fsm
index 2b000da69..cdab41359 100644
--- a/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_16.fsm
+++ b/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_16.fsm
@@ -36,4 +36,4 @@
 
 
 
-GM1o2_16=[1+D^2+D^3+D^4   1+D+D^4];
+GM1o2_16=[1+D+D^4  1+D^2+D^3+D^4 ] = [25,23] (decimal)
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_4.fsm b/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_4.fsm
index 33e5ee315..fb316b5ef 100644
--- a/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_4.fsm
+++ b/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_4.fsm
@@ -11,7 +11,4 @@
 2 1
 
 AWGN CC from Proakis-Salehi pg 779
-GM1o2_4=[1+D+D^2   1+D^2];
-
-
-
+GM1o2_4=[1+D^2, 1+D+D^2] = [5, 7] (in decimal);
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_8.fsm b/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_8.fsm
index dd63b1ef5..604bac6c2 100644
--- a/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_8.fsm
+++ b/gnuradio-examples/python/channel-coding/fsm_files/awgn1o2_8.fsm
@@ -21,4 +21,4 @@
 
 
 1/2 8-state code (Proakis pg. 493)
-GM1o2_8=[ 1+D+D^2+D^3   1+D+D^3];
+GM1o2_8=[ 1+D+D^3   1+D+D^2+D^3] =[13 , 15] (decimal)
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4.fsm b/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4.fsm
index 567948e78..3ac57be18 100644
--- a/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4.fsm
+++ b/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4.fsm
@@ -1,44 +1,15 @@
 4 4 8
 
-0	2	1	3
-0	2	1	3
-0	2	1	3
-0	2	1	3
-
-0 3 5 6
-4 7 1 2
-7 4 2 1
-3 0 6 5 
-
-
-This is generated by the 1/2 AWGN code (5 7) by puncturing the first (MSB) bit.
---> d_free=3
-
-before puncturing:
-
-00 03 31 32
-30 33 01 02
-13 10 22 21
-23 20 12 11
-
-or in decimal representation:
-
- 0  3 13 14
-12 15  1  2
- 7  4 10  9
-11  8  6  5
-
-by punturing the MSB you get (dmin=3)
-
-0 3 5 6
-4 7 1 2
-7 4 2 1
-3 0 6 5 
-
-and by puncturing the LSB (something is wrong with this code)
-
-0	1	6	7
-6	7	0	1
-3	2	5	4
-5	4	3	2
-
+0       1       2       3
+0       1       2       3
+0       1       2       3
+0       1       2       3
+
+0       7       4       3
+3       4       7       0
+5       2       1       6
+6       1       2       5
+
+I don't remeber how I generated this one...
+it is a bit better than awgn2o3_4_msb and worse
+than awgn2o3_4_msbG.
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4_1.fsm b/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4_1.fsm
deleted file mode 100644
index c5aee6983..000000000
--- a/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4_1.fsm
+++ /dev/null
@@ -1,42 +0,0 @@
-4 4 8
-
-0       1       2       3
-0       1       2       3
-0       1       2       3
-0       1       2       3
-
-0       7       4       3
-3       4       7       0
-5       2       1       6
-6       1       2       5
-
-
-
-This is generated by the 1/2 AWGN code (5 7) by puncturing the first (MSB) bit.
---> d_free=3
-
-before puncturing:
-
-
-or in decimal representation:
-
-0       7       12      11
-3       4       15      8
-13      10      1       6
-14      9       2       5
-
-by punturing the MSB you get (dmin=3)
-
-0       7       4       3
-3       4       7       0
-5       2       1       6
-6       1       2       5
-
-
-and by puncturing the LSB (something is wrong with this code)
-
-0       3       6       5
-1       2       7       4
-6       5       0       3
-7       4       1       2
-
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4_msb.fsm b/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4_msb.fsm
new file mode 100644
index 000000000..551b71101
--- /dev/null
+++ b/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4_msb.fsm
@@ -0,0 +1,46 @@
+4 4 8
+
+0	1	2	3
+0	1	2	3
+0	1	2	3
+0	1	2	3
+
+0 	5 	3 	6
+4 	1 	7 	2
+7 	2 	4 	1
+3 	6 	0 	5 
+
+
+This is generated by the 1/2 AWGN code (5 7) operated twice, ie,
+(xk+1 xki) [xk-1 xk-2] -> [xk+1 xki].
+We also puncture the first (MSB) bit.
+This code is worse than awgn2o3_4_msbG and slightly worse than
+awgn2o3_4, BUT seems to be a good innner code for sctcm (with 8PSK natural).
+
+intermediate states:
+
+00 21 02 23
+00 21 02 23
+10 31 12 33
+10 31 12 33
+
+output before puncturing:
+
+00 31 03 32
+30 01 33 02
+13 22 10 21
+23 12 20 11
+
+output after punturing the MSB:
+
+00 11 03 12
+10 01 13 02
+13 02 10 01
+03 12 00 11
+
+and in decimal:
+
+0 5 3 6
+4 1 7 2
+7 2 4 1
+3 6 0 5
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4_msbG.fsm b/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4_msbG.fsm
new file mode 100644
index 000000000..8956c53da
--- /dev/null
+++ b/gnuradio-examples/python/channel-coding/fsm_files/awgn2o3_4_msbG.fsm
@@ -0,0 +1,60 @@
+4 4 8
+
+0	1	2	3
+0	1	2	3
+0	1	2	3
+0	1	2	3
+
+0 	4 	2 	6
+5 	1 	3 	7
+3 	7 	5 	1
+
+
+This is generated by the 1/2 AWGN code (5 7) operated twice, ie,
+(xk+1 xki) [xk-1 xk-2] -> [xk+1 xki].
+We also puncture the first (MSB) bit and Gray map the symbols.
+
+intermediate states:
+
+00 21 02 23
+00 21 02 23
+10 31 12 33
+10 31 12 33
+
+output before puncturing:
+
+00 31 03 32
+30 01 33 02
+13 22 10 21
+23 12 20 11
+
+output after punturing the MSB:
+
+00 11 03 12
+10 01 13 02
+13 02 10 01
+03 12 00 11
+
+and in decimal:
+
+0 5 3 6
+4 1 7 2
+7 2 4 1
+3 6 0 5
+
+After Gray mapping:
+label -> phase
+0 -> 0
+1 -> 0
+2 -> 7
+3 -> 2
+4 -> 5
+5 -> 4
+6 -> 6
+7 -> 3
+
+0 4 2 6
+5 1 3 7
+3 7 5 1
+2 6 0 4
+
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/awgn2o4_4.fsm b/gnuradio-examples/python/channel-coding/fsm_files/awgn2o4_4.fsm
index 793d419c5..a895be896 100644
--- a/gnuradio-examples/python/channel-coding/fsm_files/awgn2o4_4.fsm
+++ b/gnuradio-examples/python/channel-coding/fsm_files/awgn2o4_4.fsm
@@ -1,14 +1,36 @@
-4 4 16 
+4 4 16
 
-0   2   1   3
-0   2   1   3
-0   2   1   3
-0   2   1   3
+0	1	2	3
+0	1	2	3
+0	1	2	3
+0	1	2	3
 
- 0  3 13 14
-12 15  1  2
- 7  4 10  9
-11  8  6  5
+ 0 	13 	 3 	14
+12 	 1 	15 	 2
+ 7 	10 	 4 	 9
+11 	 6 	 8 	 5
 
-generated by the awgn1o2_4.fsm code
-(two steps of the 1o2 code)
+
+This is generated by the 1/2 AWGN code (5 7) operated twice, ie,
+(xk+1 xki) [xk-1 xk-2] -> [xk+1 xki].
+
+intermediate states:
+
+00 21 02 23
+00 21 02 23
+10 31 12 33
+10 31 12 33
+
+output:
+
+00 31 03 32
+30 01 33 02
+13 22 10 21
+23 12 20 11
+
+and in decimal:
+
+ 0 13  3 14
+12  1 15  2
+ 7 10  4  9
+11  6  8  5
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/disconnected.fsm b/gnuradio-examples/python/channel-coding/fsm_files/disconnected.fsm
new file mode 100644
index 000000000..847963e7b
--- /dev/null
+++ b/gnuradio-examples/python/channel-coding/fsm_files/disconnected.fsm
@@ -0,0 +1,11 @@
+1 4 1
+
+1
+0
+3
+2
+
+0
+0
+0
+0
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/rep3.fsm b/gnuradio-examples/python/channel-coding/fsm_files/rep3.fsm
index 1930523b3..ef1bd1f02 100644
--- a/gnuradio-examples/python/channel-coding/fsm_files/rep3.fsm
+++ b/gnuradio-examples/python/channel-coding/fsm_files/rep3.fsm
@@ -4,4 +4,5 @@
 
 0 7
 
-1/3 repetition code (with binary input)
+1/3 repetition code (with binary input).
+There is only one state, since this is essentially a memoryless system.
diff --git a/gnuradio-examples/python/channel-coding/fsm_files/simple.fsm b/gnuradio-examples/python/channel-coding/fsm_files/simple.fsm
new file mode 100644
index 000000000..07fb0852f
--- /dev/null
+++ b/gnuradio-examples/python/channel-coding/fsm_files/simple.fsm
@@ -0,0 +1,13 @@
+1 4 1
+
+1
+2
+3
+0
+
+0
+0
+0
+0
+
+essentially this fsm has no inputs and no outputs; it ijust cycles through all 4 states.
diff --git a/gnuradio-examples/python/channel-coding/fsm_utils.py b/gnuradio-examples/python/channel-coding/fsm_utils.py
index dc5ee79f1..fe9f4f3b8 100755
--- a/gnuradio-examples/python/channel-coding/fsm_utils.py
+++ b/gnuradio-examples/python/channel-coding/fsm_utils.py
@@ -60,101 +60,6 @@ def base2dec(s,base):
 
 
 
-
-
-######################################################################
-# Automaticaly generate the FSM structure for a binary feed-forward
-# convolutional code.
-# Input: k x n generator matrix (decimal representation)
-######################################################################
-def make_fsm_bin_cc_ff(k,n,GM):
-    mem=[[]]*k
-    max_mem_x=[-1]*k
-    max_mem = -1
-    for i in range(k):
-        memr=[0]*n
-        for j in range(n):
-            if GM[i][j]==0:
-                memr[j]=-1
-            else:
-                memr[j]=int(math.log(GM[i][j],2))
-            if memr[j]>max_mem_x[i]:
-                max_mem_x[i]=memr[j]
-            if memr[j]>max_mem:
-                max_mem=memr[j]
-        mem[i]=memr
-
-    sum_max_mem = 0
-    for i in range(k):
-       sum_max_mem = sum_max_mem+max_mem_x[i] 
-        
-
-    #print mem
-    #print max_mem_x
-    #print max_mem
-    #print sum_max_mem
-
-    I=2**k
-    S=2**sum_max_mem
-    O=2**n
-
-    #print I, S, O
-
-    NS=[0]*S*I;
-    OS=[0]*S*I;
-    for s in range(S):
-        for i in range(I):
-            ss=dec2base(s,2,sum_max_mem)
-            ind=0
-            ss_r=[]
-            for kk in range(k):
-                ss1 = [0]*max_mem
-                ss1[0:max_mem_x[kk]] = ss[ind:ind+max_mem_x[kk]]
-                ss_r.append(ss1)
-                ind=ind+max_mem_x[kk]
-            ii=dec2base(i,2,k)
-
-            tt_r = ss_r
-            for kk in range(k):
-                tt_r[kk].insert(0,ii[kk])
-            #print tt_r
-
-            ns_r = []
-            for kk in range(k):
-                ns_r.append(tt_r[kk][0:max_mem])
-
-            ns=[]
-            for kk in range(k):
-                ns = ns + ns_r[kk][0:max_mem_x[kk]]
-            NS[s*I+i]=base2dec(ns,2);
-
-            out_r=[0]*n
-            for nn in range(n):
-                out=0;
-                for kk in range(k):
-                    c=[0]*max_mem
-                    gm = dec2base(GM[kk][nn],2,max_mem_x[kk]+1)
-                    gm.reverse()
-                    c[0:len(gm)] = gm
-                    sy = 0
-                    for m in range(len(c)):
-                        sy = sy + c[m]*tt_r[kk][m];
-                    out=operator.mod(out+sy,2);
-                out_r[nn]=out;
-            out_r.reverse()
-            OS[s*I+i] = base2dec(out_r,2);
-    
-    #O=max(max(OS))+1;
-    print I, S, O
-    print NS
-    print OS
-
-    return (I,S,O,NS,OS)
-
-
-
-
-
 ######################################################################
 # Automatically generate the lookup table that maps the FSM outputs
 # to channel inputs corresponding to a channel 'channel' and a modulation
diff --git a/gnuradio-examples/python/channel-coding/test_sccc_hard.py b/gnuradio-examples/python/channel-coding/test_sccc_hard.py
index a869e91e1..d634282fe 100755
--- a/gnuradio-examples/python/channel-coding/test_sccc_hard.py
+++ b/gnuradio-examples/python/channel-coding/test_sccc_hard.py
@@ -18,7 +18,7 @@ def run_test (fo,fi,interleaver,Kb,bitspersymbol,K,dimensionality,constellation,
     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 outer FSM input cardinality
     enc_out = trellis.encoder_ss(fo,0) # initial state = 0
-    inter = trellis.permutation(interleaver.K(),interleaver.INTER(),gr.sizeof_short)
+    inter = trellis.permutation(interleaver.K(),interleaver.INTER(),1,gr.sizeof_short)
     enc_in = trellis.encoder_ss(fi,0) # initial state = 0
     mod = gr.chunks_to_symbols_sf(constellation,dimensionality)
 
@@ -29,7 +29,7 @@ def run_test (fo,fi,interleaver,Kb,bitspersymbol,K,dimensionality,constellation,
     # RX
     metrics_in = trellis.metrics_f(fi.O(),dimensionality,constellation,trellis.TRELLIS_EUCLIDEAN) # data preprocessing to generate metrics for innner Viterbi
     va_in = trellis.viterbi_s(fi,K,0,-1) # Put -1 if the Initial/Final states are not set.
-    deinter = trellis.permutation(interleaver.K(),interleaver.DEINTER(),gr.sizeof_short)
+    deinter = trellis.permutation(interleaver.K(),interleaver.DEINTER(),1,gr.sizeof_short)
     metrics_out = trellis.metrics_s(fo.O(),1,[0,1,2,3],trellis.TRELLIS_HARD_SYMBOL) # data preprocessing to generate metrics for outer Viterbi (hard decisions)
     va_out = trellis.viterbi_s(fo,K,0,-1) # Put -1 if the Initial/Final states are not set.
     fsmi2s = gr.unpacked_to_packed_ss(bitspersymbol,gr.GR_MSB_FIRST) # pack FSM input symbols to shorts
@@ -85,14 +85,16 @@ def main(args):
     
     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,constellation,N0,-long(666+i)) # run experiment with different seed to get different noise realizations
         tot_s=tot_s+s
         terr_s=terr_s+e
-        if (i%100==0) & (i>0): # display progress
-            print i,s,e,tot_s,terr_s, '%e' % ((1.0*terr_s)/tot_s)
+        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 bit) error rate
-    print tot_s,terr_s, '%e' % ((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__':
diff --git a/gnuradio-examples/python/channel-coding/test_sccc_soft.py b/gnuradio-examples/python/channel-coding/test_sccc_soft.py
new file mode 100755
index 000000000..23e6553ca
--- /dev/null
+++ b/gnuradio-examples/python/channel-coding/test_sccc_soft.py
@@ -0,0 +1,108 @@
+#!/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 run_test (fo,fi,interleaver,Kb,bitspersymbol,K,dimensionality,constellation,N0,seed):
+    fg = gr.flow_graph ()
+
+
+    # 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 outer 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
+    mod = gr.chunks_to_symbols_sf(constellation,dimensionality)
+
+    # CHANNEL
+    add = gr.add_ff()
+    noise = gr.noise_source_f(gr.GR_GAUSSIAN,math.sqrt(N0/2),seed)
+
+    # RX
+    metrics_in = trellis.metrics_f(fi.O(),dimensionality,constellation,trellis.TRELLIS_EUCLIDEAN) # data preprocessing to generate metrics for innner Viterbi
+    gnd = gr.vector_source_f([0],True);
+    siso_in = trellis.siso_f(fi,K,0,-1,True,False,trellis.TRELLIS_MIN_SUM) # Put -1 if the Initial/Final states are not set.
+    deinter = trellis.permutation(interleaver.K(),interleaver.DEINTER(),fi.I(),gr.sizeof_float)
+    va_out = trellis.viterbi_s(fo,K,0,-1) # Put -1 if the Initial/Final states are not set.
+    fsmi2s = gr.unpacked_to_packed_ss(bitspersymbol,gr.GR_MSB_FIRST) # pack FSM input symbols to shorts
+    dst = gr.check_lfsr_32k_s()
+    
+    fg.connect (src,src_head,s2fsmi,enc_out,inter,enc_in,mod)
+    fg.connect (mod,(add,0))
+    fg.connect (noise,(add,1))
+    fg.connect (add,metrics_in)
+    fg.connect (gnd,(siso_in,0))
+    fg.connect (metrics_in,(siso_in,1))
+    fg.connect (siso_in,deinter,va_out,fsmi2s,dst)
+
+    fg.run()
+    
+    ntotal = dst.ntotal ()
+    nright = dst.nright ()
+    runlength = dst.runlength ()
+    return (ntotal,ntotal-nright)
+
+
+def main(args):
+    nargs = len (args)
+    if nargs == 4:
+        fname_out=args[0]
+        fname_in=args[1]
+        esn0_db=float(args[2]) # Es/No in dB
+        rep=int(args[3]) # number of times the experiment is run to collect enough errors
+    else:
+        sys.stderr.write ('usage: test_tcm.py fsm_name_out fsm_fname_in Es/No_db  repetitions\n')
+        sys.exit (1)
+
+    # system parameters
+    Kb=1024*16  # packet size in bits (make it multiple of 16 so it can be packed in a short)
+    fo=trellis.fsm(fname_out) # get the outer FSM specification from a file
+    fi=trellis.fsm(fname_in) # get the innner FSM specification from a file
+    bitspersymbol = int(round(math.log(fo.I())/math.log(2))) # bits per FSM input symbol
+    if fo.O() != fi.I():
+        sys.stderr.write ('Incompatible cardinality between outer and inner FSM.\n')
+        sys.exit (1)
+    K=Kb/bitspersymbol # packet size in trellis steps
+    interleaver=trellis.interleaver(K,666) # construct a random interleaver
+    modulation = fsm_utils.psk8 # see fsm_utlis.py for available predefined modulations
+    dimensionality = modulation[0]
+    constellation = modulation[1] 
+    if len(constellation)/dimensionality != fi.O():
+        sys.stderr.write ('Incompatible FSM output cardinality and modulation size.\n')
+        sys.exit (1)
+    # calculate average symbol energy
+    Es = 0
+    for i in range(len(constellation)):
+        Es = Es + constellation[i]**2
+    Es = Es / (len(constellation)/dimensionality)
+    N0=Es/pow(10.0,esn0_db/10.0); # calculate noise variance
+
+
+    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,constellation,N0,-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)%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 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:])
diff --git a/gnuradio-examples/python/channel-coding/test_sccc_turbo.py b/gnuradio-examples/python/channel-coding/test_sccc_turbo.py
new file mode 100755
index 000000000..cdd1ad8b0
--- /dev/null
+++ b/gnuradio-examples/python/channel-coding/test_sccc_turbo.py
@@ -0,0 +1,139 @@
+#!/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(fg,fo,fi,dimensionality,constellation,K,interleaver,IT,Es,N0,type):
+    metrics_in = trellis.metrics_f(fi.O(),dimensionality,constellation,trellis.TRELLIS_EUCLIDEAN) # data preprocessing to generate metrics for innner Viterbi
+    scale = gr.multiply_const_ff(1.0/N0)
+    gnd = gr.vector_source_f([0],True);
+
+    inter=[]
+    deinter=[]
+    siso_in=[]
+    siso_out=[]
+
+    for it in range(IT-1):
+      inter.append( trellis.permutation(interleaver.K(),interleaver.INTER(),fi.I(),gr.sizeof_float) )
+      siso_in.append( trellis.siso_f(fi,K,0,3,True,False,type) )
+      deinter.append( trellis.permutation(interleaver.K(),interleaver.DEINTER(),fi.I(),gr.sizeof_float) )
+      siso_out.append( trellis.siso_f(fo,K,0,3,False,True,type) )
+      fg.connect (inter[it],(siso_in[it],0))
+      fg.connect (gnd,(siso_out[it],0))
+      fg.connect (siso_in[it],deinter[it],(siso_out[it],1))
+
+    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) )
+    siso_out.append( trellis.viterbi_s(fo,K,0,-1) )
+    fg.connect (inter[IT-1],(siso_in[IT-1],0))
+    fg.connect (siso_in[IT-1],deinter[IT-1],siso_out[IT-1])
+
+    # connect first stage
+    fg.connect (gnd,inter[0])
+    fg.connect (metrics_in,scale)
+    fg.connect (scale,(siso_in[0],1))
+    for it in range(IT-1):
+      fg.connect (siso_out[it],inter[it+1])
+      fg.connect (metrics_in,(siso_in[it+1],1))
+    return (metrics_in,siso_out[IT-1])
+
+
+def run_test (fo,fi,interleaver,Kb,bitspersymbol,K,dimensionality,constellation,Es,N0,IT,seed):
+    fg = gr.flow_graph ()
+
+
+    # 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 outer 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
+    mod = gr.chunks_to_symbols_sf(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(fg,fo,fi,dimensionality,constellation,K,interleaver,IT,Es,N0,trellis.TRELLIS_MIN_SUM)
+    #(head,tail) = make_rx(fg,fo,fi,dimensionality,constellation,K,interleaver,IT,Es,N0,trellis.TRELLIS_SUM_PRODUCT)
+    fsmi2s = gr.unpacked_to_packed_ss(bitspersymbol,gr.GR_MSB_FIRST) # pack FSM input symbols to shorts
+    dst = gr.check_lfsr_32k_s()
+    
+    fg.connect (src,src_head,s2fsmi,enc_out,inter,enc_in,mod)
+    fg.connect (mod,(add,0))
+    fg.connect (noise,(add,1))
+    fg.connect (add,head)
+    fg.connect (tail,fsmi2s,dst)
+
+    fg.run()
+ 
+    #print enc_out.ST(), enc_in.ST()
+    
+    ntotal = dst.ntotal ()
+    nright = dst.nright ()
+    runlength = dst.runlength ()
+    return (ntotal,ntotal-nright)
+
+
+def main(args):
+    nargs = len (args)
+    if nargs == 4:
+        fname_out=args[0]
+        fname_in=args[1]
+        esn0_db=float(args[2]) # Es/No in dB
+        rep=int(args[3]) # number of times the experiment is run to collect enough errors
+    else:
+        sys.stderr.write ('usage: test_tcm.py fsm_name_out fsm_fname_in Es/No_db  repetitions\n')
+        sys.exit (1)
+
+    # system parameters
+    Kb=1024*16  # packet size in bits (make it multiple of 16 so it can be packed in a short)
+    fo=trellis.fsm(fname_out) # get the outer FSM specification from a file
+    fi=trellis.fsm(fname_in) # get the innner FSM specification from a file
+    bitspersymbol = int(round(math.log(fo.I())/math.log(2))) # bits per FSM input symbol
+    if fo.O() != fi.I():
+        sys.stderr.write ('Incompatible cardinality between outer and inner FSM.\n')
+        sys.exit (1)
+    K=Kb/bitspersymbol # packet size in trellis steps
+    interleaver=trellis.interleaver(K,666) # construct a random interleaver
+    modulation = fsm_utils.psk8 # see fsm_utlis.py for available predefined modulations
+    dimensionality = modulation[0]
+    constellation = modulation[1] 
+    if len(constellation)/dimensionality != fi.O():
+        sys.stderr.write ('Incompatible FSM output cardinality and modulation size.\n')
+        sys.exit (1)
+    # calculate average symbol energy
+    Es = 0
+    for i in range(len(constellation)):
+        Es = Es + constellation[i]**2
+    Es = Es / (len(constellation)/dimensionality)
+    N0=Es/pow(10.0,esn0_db/10.0); # calculate 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,constellation,Es,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:])
diff --git a/gnuradio-examples/python/channel-coding/test_tcm.py b/gnuradio-examples/python/channel-coding/test_tcm.py
index 1f892ef99..f22501558 100755
--- a/gnuradio-examples/python/channel-coding/test_tcm.py
+++ b/gnuradio-examples/python/channel-coding/test_tcm.py
@@ -101,14 +101,17 @@ def main(args):
     
     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,dimensionality,constellation,N0,-long(666+i)) # run experiment with different seed to get different noise realizations
         tot_s=tot_s+s
         terr_s=terr_s+e
-        if (i%100==0) & (i>0): # display progress
-            print i,s,e,tot_s,terr_s, '%e' % ((1.0*terr_s)/tot_s)
+        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 bit) error rate
-    print tot_s,terr_s, '%e' % ((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__':
diff --git a/gnuradio-examples/python/channel-coding/test_tcm1.py b/gnuradio-examples/python/channel-coding/test_tcm1.py
index e4f88d0b5..66d7131e3 100755
--- a/gnuradio-examples/python/channel-coding/test_tcm1.py
+++ b/gnuradio-examples/python/channel-coding/test_tcm1.py
@@ -102,17 +102,19 @@ def main(args):
     Es = Es / (len(constellation)/dimensionality)
     N0=Es/pow(10.0,esn0_db/10.0); # noise variance
     
-
-    tot_s=0
-    terr_s=0
+    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,dimensionality,constellation,N0,-long(666+i)) # run experiment with different seed to get different noise realizations
         tot_s=tot_s+s
         terr_s=terr_s+e
-        if (i%1==0) & (i>0):
-            print i,s,e,tot_s,terr_s, '%e' % ((1.0*terr_s)/tot_s)
+        terr_p=terr_p+(terr_s!=0)
+        if ((i+1)%1==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 tot_s,terr_s, '%e' % ((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__':
diff --git a/gnuradio-examples/python/channel-coding/test_tcm2.py b/gnuradio-examples/python/channel-coding/test_tcm2.py
new file mode 100755
index 000000000..9680909ea
--- /dev/null
+++ b/gnuradio-examples/python/channel-coding/test_tcm2.py
@@ -0,0 +1,116 @@
+#!/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 run_test (f,Kb,bitspersymbol,K,dimensionality,constellation,N0,seed):
+    fg = gr.flow_graph ()
+
+
+    # TX
+    #packet = [0]*Kb
+    #for i in range(Kb-1*16): # last 16 bits = 0 to drive the final state to 0
+        #packet[i] = random.randint(0, 1) # random 0s and 1s
+    #src = gr.vector_source_s(packet,False)
+    src = gr.lfsr_32k_source_s()
+    src_head = gr.head (gr.sizeof_short,Kb/16) # packet size in shorts
+    #b2s = gr.unpacked_to_packed_ss(1,gr.GR_MSB_FIRST) # pack bits in shorts
+    s2fsmi = gr.packed_to_unpacked_ss(bitspersymbol,gr.GR_MSB_FIRST) # unpack shorts to symbols compatible with the FSM input cardinality
+    enc = trellis.encoder_ss(f,0) # initial state = 0
+    mod = gr.chunks_to_symbols_sf(constellation,dimensionality)
+
+    # CHANNEL
+    add = gr.add_ff()
+    noise = gr.noise_source_f(gr.GR_GAUSSIAN,math.sqrt(N0/2),seed)
+
+    # RX
+    metrics = trellis.metrics_f(f.O(),dimensionality,constellation,trellis.TRELLIS_EUCLIDEAN) # data preprocessing to generate metrics for Viterbi
+    va = trellis.viterbi_s(f,K,0,-1) # Put -1 if the Initial/Final states are not set.
+    fsmi2s = gr.unpacked_to_packed_ss(bitspersymbol,gr.GR_MSB_FIRST) # pack FSM input symbols to shorts
+    #s2b = gr.packed_to_unpacked_ss(1,gr.GR_MSB_FIRST) # unpack shorts to bits
+    #dst = gr.vector_sink_s(); 
+    dst = gr.check_lfsr_32k_s()
+    
+
+    fg.connect (src,src_head,s2fsmi,enc,mod)
+    #fg.connect (src,b2s,s2fsmi,enc,mod)
+    fg.connect (mod,(add,0))
+    fg.connect (noise,(add,1))
+    fg.connect (add,metrics)
+    fg.connect (metrics,va,fsmi2s,dst)
+    #fg.connect (metrics,va,fsmi2s,s2b,dst)
+    
+
+    fg.run()
+    
+    # A bit of cheating: run the program once and print the 
+    # final encoder state..
+    # Then put it as the last argument in the viterbi block
+    #print "final state = " , enc.ST()
+
+    ntotal = dst.ntotal ()
+    nright = dst.nright ()
+    runlength = dst.runlength ()
+    #ntotal = len(packet)
+    #if len(dst.data()) != ntotal:
+        #print "Error: not enough data\n"
+    #nright = 0;
+    #for i in range(ntotal):
+        #if packet[i]==dst.data()[i]:
+            #nright=nright+1
+        #else:
+            #print "Error in ", i
+    return (ntotal,ntotal-nright)
+
+
+
+
+def main(args):
+    nargs = len (args)
+    if nargs == 2:
+        esn0_db=float(args[0]) # Es/No in dB
+        rep=int(args[1]) # number of times the experiment is run to collect enough errors
+    else:
+        sys.stderr.write ('usage: test_tcm2.py Es/No_db  repetitions\n')
+        sys.exit (1)
+
+    # system parameters
+    f=trellis.fsm(1,2,[5,7]) # generate FSM specification from the generator matrix
+    Kb=1024*16  # packet size in bits (make it multiple of 16 so it can be packed in a short)
+    bitspersymbol = int(round(math.log(f.I())/math.log(2))) # bits per FSM input symbol
+    K=Kb/bitspersymbol # packet size in trellis steps
+    modulation = fsm_utils.psk4 # see fsm_utlis.py for available predefined modulations
+    dimensionality = modulation[0]
+    constellation = modulation[1] 
+    if len(constellation)/dimensionality != f.O():
+        sys.stderr.write ('Incompatible FSM output cardinality and modulation size.\n')
+        sys.exit (1)
+    # calculate average symbol energy
+    Es = 0
+    for i in range(len(constellation)):
+        Es = Es + constellation[i]**2
+    Es = Es / (len(constellation)/dimensionality)
+    N0=Es/pow(10.0,esn0_db/10.0); # calculate noise variance
+    
+    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,dimensionality,constellation,N0,-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)%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 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:])
diff --git a/gnuradio-examples/python/channel-coding/test_tcm_combined.py b/gnuradio-examples/python/channel-coding/test_tcm_combined.py
index ce0863183..37f38ef1a 100755
--- a/gnuradio-examples/python/channel-coding/test_tcm_combined.py
+++ b/gnuradio-examples/python/channel-coding/test_tcm_combined.py
@@ -80,17 +80,19 @@ def main(args):
     Es = Es / (len(constellation)/dimensionality)
     N0=Es/pow(10.0,esn0_db/10.0); # noise variance
 
-
-    tot_s=0
-    terr_s=0
+    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,dimensionality,constellation,N0,-long(666+i)) # run experiment with different seed to get different noise realizations
         tot_s=tot_s+s
         terr_s=terr_s+e
-        if (i%100==0) & (i>0):
-            print i,s,e,tot_s,terr_s, '%e' % ((1.0*terr_s)/tot_s)
-    # estimate of the (short) error rate
-    print tot_s,terr_s, '%e' % ((1.0*terr_s)/tot_s)
+        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 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__':
diff --git a/gnuradio-examples/python/channel-coding/test_tcm_parallel.py b/gnuradio-examples/python/channel-coding/test_tcm_parallel.py
index 230bf4b98..f9dcb5852 100755
--- a/gnuradio-examples/python/channel-coding/test_tcm_parallel.py
+++ b/gnuradio-examples/python/channel-coding/test_tcm_parallel.py
@@ -15,7 +15,7 @@ def run_test (f,Kb,bitspersymbol,K,dimensionality,constellation,N0,seed,P):
     src = gr.lfsr_32k_source_s()
     src_head = gr.head (gr.sizeof_short,Kb/16*P) # packet size in shorts
     s2fsmi=gr.packed_to_unpacked_ss(bitspersymbol,gr.GR_MSB_FIRST) # unpack shorts to symbols compatible with the FSM input cardinality
-    s2p = gr.stream_to_streams(2,P) # serial to parallel
+    s2p = gr.stream_to_streams(gr.sizeof_short,P) # serial to parallel
     enc = trellis.encoder_ss(f,0) # initiali state = 0
     mod = gr.chunks_to_symbols_sf(constellation,dimensionality)
 
@@ -26,11 +26,10 @@ def run_test (f,Kb,bitspersymbol,K,dimensionality,constellation,N0,seed,P):
         add.append(gr.add_ff())
         noise.append(gr.noise_source_f(gr.GR_GAUSSIAN,math.sqrt(N0/2),seed))
 
-    
     # RX
     metrics = trellis.metrics_f(f.O(),dimensionality,constellation,trellis.TRELLIS_EUCLIDEAN) # data preprocessing to generate metrics for Viterbi
     va = trellis.viterbi_s(f,K,0,-1) # Put -1 if the Initial/Final states are not set.
-    p2s = gr.streams_to_stream(2,P) # parallel to serial
+    p2s = gr.streams_to_stream(gr.sizeof_short,P) # parallel to serial
     fsmi2s=gr.unpacked_to_packed_ss(bitspersymbol,gr.GR_MSB_FIRST) # pack FSM input symbols to shorts
     dst = gr.check_lfsr_32k_s()
 
@@ -90,14 +89,16 @@ def main(args):
 
     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,dimensionality,constellation,N0,-long(666+i),P) # run experiment with different seed to get different noise realizations
         tot_s=tot_s+s
         terr_s=terr_s+e
-        if (i%10==0) & (i>0): # display progress
-            print i,s,e,tot_s,terr_s, '%e' % ((1.0*terr_s)/tot_s)
+        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 bit) error rate
-    print tot_s,terr_s, '%e' % ((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__':