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Diffstat (limited to 'gr-trellis/src/examples/fsm_utils.py')
| -rwxr-xr-x | gr-trellis/src/examples/fsm_utils.py | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/gr-trellis/src/examples/fsm_utils.py b/gr-trellis/src/examples/fsm_utils.py new file mode 100755 index 000000000..1b011246c --- /dev/null +++ b/gr-trellis/src/examples/fsm_utils.py @@ -0,0 +1,213 @@ +#!/usr/bin/env python +# +# Copyright 2004 Free Software Foundation, Inc. +# +# This file is part of GNU Radio +# +# GNU Radio is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3, or (at your option) +# any later version. +# +# GNU Radio is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with GNU Radio; see the file COPYING. If not, write to +# the Free Software Foundation, Inc., 51 Franklin Street, +# Boston, MA 02110-1301, USA. +# + + +import re +import math +import sys +import operator + +from gnuradio import trellis + + + +###################################################################### +# Decimal to any base conversion. +# Convert 'num' to a list of 'l' numbers representing 'num' +# to base 'base' (most significant symbol first). +###################################################################### +def dec2base(num,base,l): + s=range(l) + n=num + for i in range(l): + s[l-i-1]=n%base + n=int(n/base) + if n!=0: + print 'Number ', num, ' requires more than ', l, 'digits.' + return s + + +###################################################################### +# Conversion from any base to decimal. +# Convert a list 's' of symbols to a decimal number +# (most significant symbol first) +###################################################################### +def base2dec(s,base): + num=0 + for i in range(len(s)): + num=num*base+s[i] + return num + + +###################################################################### +# Generate a new FSM representing the concatenation of two FSMs +###################################################################### +def fsm_concatenate(f1,f2): + if f1.O() > f2.I(): + print "Not compatible FSMs\n" + I=f1.I() + S=f1.S()*f2.S() + O=f2.O() + nsm=list([0]*I*S) + osm=list([0]*I*S) + for s1 in range(f1.S()): + for s2 in range(f2.S()): + for i in range(f1.I()): + ns1=f1.NS()[s1*f1.I()+i] + o1=f1.OS()[s1*f1.I()+i] + ns2=f2.NS()[s2*f2.I()+o1] + o2=f2.OS()[s2*f2.I()+o1] + + s=s1*f2.S()+s2 + ns=ns1*f2.S()+ns2 + nsm[s*I+i]=ns + osm[s*I+i]=o2 + + + f=trellis.fsm(I,S,O,nsm,osm) + return f + +###################################################################### +# Generate a new FSM representing n stages through the original FSM +###################################################################### +def fsm_radix(f,n): + I=f.I()**n + S=f.S() + O=f.O()**n + nsm=list([0]*I*S) + osm=list([0]*I*S) + for s in range(f.S()): + for i in range(I): + ii=dec2base(i,f.I(),n) + oo=list([0]*n) + ns=s + for k in range(n): + oo[k]=f.OS()[ns*f.I()+ii[k]] + ns=f.NS()[ns*f.I()+ii[k]] + + nsm[s*I+i]=ns + osm[s*I+i]=base2dec(oo,f.O()) + + + f=trellis.fsm(I,S,O,nsm,osm) + return f + + + + +###################################################################### +# Automatically generate the lookup table that maps the FSM outputs +# to channel inputs corresponding to a channel 'channel' and a modulation +# 'mod'. Optional normalization of channel to unit energy. +# This table is used by the 'metrics' block to translate +# channel outputs to metrics for use with the Viterbi algorithm. +# Limitations: currently supports only one-dimensional modulations. +###################################################################### +def make_isi_lookup(mod,channel,normalize): + dim=mod[0] + constellation = mod[1] + + if normalize: + p = 0 + for i in range(len(channel)): + p = p + channel[i]**2 + for i in range(len(channel)): + channel[i] = channel[i]/math.sqrt(p) + + lookup=range(len(constellation)**len(channel)) + for o in range(len(constellation)**len(channel)): + ss=dec2base(o,len(constellation),len(channel)) + ll=0 + for i in range(len(channel)): + ll=ll+constellation[ss[i]]*channel[i] + lookup[o]=ll + return (1,lookup) + + + + + + +###################################################################### +# A list of common modulations. +# Format: (dimensionality,constellation) +###################################################################### +pam2 = (1,[-1, 1]) +pam4 = (1,[-3, -1, 3, 1]) # includes Gray mapping +pam8 = (1,[-7, -5, -3, -1, 1, 3, 5, 7]) + +psk4=(2,[1, 0, \ + 0, 1, \ + 0, -1,\ + -1, 0]) # includes Gray mapping +psk8=(2,[math.cos(2*math.pi*0/8), math.sin(2*math.pi*0/8), \ + math.cos(2*math.pi*1/8), math.sin(2*math.pi*1/8), \ + math.cos(2*math.pi*2/8), math.sin(2*math.pi*2/8), \ + math.cos(2*math.pi*3/8), math.sin(2*math.pi*3/8), \ + math.cos(2*math.pi*4/8), math.sin(2*math.pi*4/8), \ + math.cos(2*math.pi*5/8), math.sin(2*math.pi*5/8), \ + math.cos(2*math.pi*6/8), math.sin(2*math.pi*6/8), \ + math.cos(2*math.pi*7/8), math.sin(2*math.pi*7/8)]) + +orth2 = (2,[1, 0, \ + 0, 1]) +orth4=(4,[1, 0, 0, 0, \ + 0, 1, 0, 0, \ + 0, 0, 1, 0, \ + 0, 0, 0, 1]) + +###################################################################### +# A list of channels to be tested +###################################################################### + +# C test channel (J. Proakis, Digital Communications, McGraw-Hill Inc., 2001) +c_channel = [0.227, 0.460, 0.688, 0.460, 0.227] + + + + + + + + + + +if __name__ == '__main__': + f1=trellis.fsm('fsm_files/awgn1o2_4.fsm') + #f2=trellis.fsm('fsm_files/awgn2o3_4.fsm') + print f1.I(), f1.S(), f1.O() + print f1.NS() + print f1.OS() + #print f2.I(), f2.S(), f2.O() + #print f2.NS() + #print f2.OS() + ##f1.write_trellis_svg('f1.svg',4) + #f2.write_trellis_svg('f2.svg',4) + #f=fsm_concatenate(f1,f2) + f=fsm_radix(f1,2) + + print "----------\n" + print f.I(), f.S(), f.O() + print f.NS() + print f.OS() + #f.write_trellis_svg('f.svg',4) + |