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Diffstat (limited to 'gr-trellis/src/examples/python/fsm_utils.py')
| -rwxr-xr-x | gr-trellis/src/examples/python/fsm_utils.py | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/gr-trellis/src/examples/python/fsm_utils.py b/gr-trellis/src/examples/python/fsm_utils.py new file mode 100755 index 000000000..e9243f899 --- /dev/null +++ b/gr-trellis/src/examples/python/fsm_utils.py @@ -0,0 +1,239 @@ +#!/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 +import numpy + +from gnuradio import trellis + +try: + import scipy.linalg +except ImportError: + print "Error: Program requires scipy (see: www.scipy.org)." + sys.exit(1) + + + +###################################################################### +# 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 + + + + +###################################################################### +# 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) + + + + + + +###################################################################### +# Automatically generate the signals appropriate for CPM +# decomposition. +# This decomposition is based on the paper by B. Rimoldi +# "A decomposition approach to CPM", IEEE Trans. Info Theory, March 1988 +# See also my own notes at http://www.eecs.umich.edu/~anastas/docs/cpm.pdf +###################################################################### +def make_cpm_signals(K,P,M,L,q,frac): + + Q=numpy.size(q)/L + h=(1.0*K)/P + f0=-h*(M-1)/2 + dt=0.0; # maybe start at t=0.5 + t=(dt+numpy.arange(0,Q))/Q + qq=numpy.zeros(Q) + for m in range(L): + qq=qq + q[m*Q:m*Q+Q] + w=math.pi*h*(M-1)*t-2*math.pi*h*(M-1)*qq+math.pi*h*(L-1)*(M-1) + + X=(M**L)*P + PSI=numpy.empty((X,Q)) + for x in range(X): + xv=dec2base(x/P,M,L) + xv=numpy.append(xv, x%P) + qq1=numpy.zeros(Q) + for m in range(L): + qq1=qq1+xv[m]*q[m*Q:m*Q+Q] + psi=2*math.pi*h*xv[-1]+4*math.pi*h*qq1+w + #print psi + PSI[x]=psi + PSI = numpy.transpose(PSI) + SS=numpy.exp(1j*PSI) # contains all signals as columns + #print SS + + + # Now we need to orthogonalize the signals + F = scipy.linalg.orth(SS) # find an orthonormal basis for SS + #print numpy.dot(numpy.transpose(F.conjugate()),F) # check for orthonormality + S = numpy.dot(numpy.transpose(F.conjugate()),SS) + #print F + #print S + + # We only want to keep those dimensions that contain most + # of the energy of the overall constellation (eg, frac=0.9 ==> 90%) + # evaluate mean energy in each dimension + E=numpy.sum(numpy.absolute(S)**2,axis=1)/Q + E=E/numpy.sum(E) + #print E + Es = -numpy.sort(-E) + Esi = numpy.argsort(-E) + #print Es + #print Esi + Ecum=numpy.cumsum(Es) + #print Ecum + v0=numpy.searchsorted(Ecum,frac) + N = v0+1 + #print v0 + #print Esi[0:v0+1] + Ff=numpy.transpose(numpy.transpose(F)[Esi[0:v0+1]]) + #print Ff + Sf = S[Esi[0:v0+1]] + #print Sf + + + return (f0,SS,S,F,Sf,Ff,N) + #return f0 + + + + +###################################################################### +# 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) + + q=numpy.arange(0,8)/(2.0*8) + (f0,SS,S,F,Sf,Ff,N) = make_cpm_signals(1,2,2,1,q,0.99) + |