diff options
| author | anastas <anastas@221aa14e-8319-0410-a670-987f0aec2ac5> | 2009-02-26 00:29:51 +0000 |
|---|---|---|
| committer | anastas <anastas@221aa14e-8319-0410-a670-987f0aec2ac5> | 2009-02-26 00:29:51 +0000 |
| commit | 436f3744f211b396b68fd58699063047899b7281 (patch) | |
| tree | 2505fb981bc452f867b4633a11e57b188a565d01 /gr-trellis/src/examples/fsm_utils.py | |
| parent | 4d192c227e6c7a00b82aef4aca71a3a77ac0dbd1 (diff) | |
Added support for Continuous Phase Modulation in gr-trellis + an example
git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@10514 221aa14e-8319-0410-a670-987f0aec2ac5
Diffstat (limited to 'gr-trellis/src/examples/fsm_utils.py')
| -rwxr-xr-x | gr-trellis/src/examples/fsm_utils.py | 118 |
1 files changed, 83 insertions, 35 deletions
diff --git a/gr-trellis/src/examples/fsm_utils.py b/gr-trellis/src/examples/fsm_utils.py index 1b011246c8..ab7b4e9468 100755 --- a/gr-trellis/src/examples/fsm_utils.py +++ b/gr-trellis/src/examples/fsm_utils.py @@ -25,6 +25,8 @@ import re import math import sys import operator +import numpy +import scipy.linalg from gnuradio import trellis @@ -58,33 +60,6 @@ def base2dec(s,base): 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 @@ -143,6 +118,76 @@ def make_isi_lookup(mod,channel,normalize): 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 @@ -194,20 +239,23 @@ 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 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) + #f=fsm_radix(f1,2) - print "----------\n" - print f.I(), f.S(), f.O() - print f.NS() - print f.OS() + #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) + |