freedv-gui/codec2-1.2.0/octave/tfmfsk.m

498 lines
14 KiB
Matlab

% tfsk.m
% Author: Brady O'Brien 8 February 2016
% Copyright 2016 David Rowe
%
% All rights reserved.
%
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU Lesser General Public License version 2.1, as
% published by the Free Software Foundation. This program 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 Lesser General Public License
% along with this program; if not, see <http://www.gnu.org/licenses/>.
% Octave script to check c port of mancyfsk/fmfsk against the fmfsk.m
%
#{
FMFSK Modem automated test instructions:
1. Use cmake to build in debug mode to ensure unittest/tfsk is built:
$ cd ~/codec2
$ rm -Rf build_linux && mkdir build_linux
$ cd build_linux
$ cmake -DCMAKE_BUILD_TYPE=Debug ..
$ make
2 - Change tfsk_location below if required
3 - Ensure Octave packages signal and parallel are installed
4 - Start Octave and run tfsk.m. It will perform all tests automatically
#}
%tfsk executable path/file
global tfsk_location = '../build_linux/unittest/tfmfsk';
%Set to 1 for verbose printouts
global print_verbose = 0;
fmfsk
pkg load signal;
pkg load parallel;
graphics_toolkit('gnuplot');
global mod_pass_fail_maxdiff = 1e-3/5000;
function mod = fmfsk_mod_c(Fs,Rs,bits)
global tfsk_location;
%command to be run by system to launch the modulator
command = sprintf('%s M %d %d fsk_mod_ut_bitvec fsk_mod_ut_modvec fmfsk_mod_ut_log.txt',tfsk_location,Fs,Rs);
%save input bits into a file
bitvecfile = fopen('fsk_mod_ut_bitvec','wb+');
fwrite(bitvecfile,bits,'uint8');
fclose(bitvecfile);
%run the modulator
system(command);
modvecfile = fopen('fsk_mod_ut_modvec','rb');
mod = fread(modvecfile,'single');
fclose(modvecfile);
endfunction
%Compare 2 vectors, fail if they are not close enough
function pass = vcompare(vc,voct,vname,tname,tol,pnum)
global print_verbose;
%Get delta of vectors
dvec = abs(abs(vc)-abs(voct));
%Normalize difference
dvec = dvec ./ abs(max(abs(voct))+1e-8);
maxdvec = abs(max(dvec));
pass = maxdvec<tol;
if print_verbose == 1
printf(' Comparing vectors %s in test %s. Diff is %f\n',vname,tname,maxdvec);
end
if pass == 0
printf('\n*** vcompare failed %s in test %s. Diff: %f Tol: %f\n\n',vname,tname,maxdvec,tol);
titlestr = sprintf('Diff between C and Octave of %s for %s',vname,tname)
figure(10+pnum*2)
plot(abs(dvec))
title(titlestr)
figure(11+pnum*2)
plot((1:length(vc)),abs(vc),(1:length(voct)),abs(voct))
end
endfunction
function test_stats = fmfsk_demod_xt(Fs,Rs,mod,tname,M=2)
global tfsk_location;
%Name of executable containing the modulator
modvecfilename = sprintf('fmfsk_demod_ut_modvec_%d',getpid());
bitvecfilename = sprintf('fmfsk_demod_ut_bitvec_%d',getpid());
tvecfilename = sprintf('fmfsk_demod_ut_tracevec_%d.txt',getpid());
%command to be run by system to launch the demod
command = sprintf('%s D %d %d %s %s %s',tfsk_location,Fs,Rs,modvecfilename,bitvecfilename,tvecfilename);
%save modulated input into a file
modvecfile = fopen(modvecfilename,'wb+');
fwrite(modvecfile,mod,'single');
fclose(modvecfile);
%run the modulator
system(command);
bitvecfile = fopen(bitvecfilename,'rb');
bits = fread(bitvecfile,'uint8');
fclose(bitvecfile);
bits = bits!=0;
%Load test vec dump
load(tvecfilename);
%Clean up files
delete(bitvecfilename);
delete(modvecfilename);
delete(tvecfilename);
o_norm_rx_timing = [];
o_symsamp = [];
o_rx_filt = [];
%Run octave demod, dump some test vectors
states = fmfsk_init(Fs,Rs);
Ts = states.Ts;
modin = mod;
obits = [];
while length(modin)>=states.nin
ninold = states.nin;
[bitbuf,states] = fmfsk_demod(states, modin(1:states.nin));
modin=modin(ninold+1:length(modin));
obits = [obits bitbuf];
o_norm_rx_timing = [o_norm_rx_timing states.norm_rx_timing];
o_symsamp = [o_symsamp states.symsamp];
o_rx_filt = [o_rx_filt states.rx_filt];
end
close all
pass = 1;
% One part-per-thousand allowed on important parameters
pass = vcompare(t_rx_filt,o_rx_filt,'rx filt',tname,.001,8) && pass;
pass = vcompare(t_norm_rx_timing,o_norm_rx_timing,'norm rx timing',tname,.001,9) && pass;
pass = vcompare(t_symsamp,o_symsamp,'symsamp',tname,.001,10) && pass;
assert(pass);
diffpass = sum(xor(obits,bits'))<4;
diffbits = sum(xor(obits,bits'));
if diffpass==0
printf('\n***bitcompare test failed test %s diff %d\n\n',tname,sum(xor(obits,bits')))
figure(15)
plot(xor(obits,bits'))
title(sprintf('Bitcompare failure test %s',tname))
end
pass = pass && diffpass;
test_stats.pass = pass;
test_stats.diff = sum(xor(obits,bits'));
test_stats.cbits = bits';
test_stats.obits = obits;
endfunction
function [dmod,cmod,omod,pass] = fmfsk_mod_test(Fs,Rs,bits,tname,M=2)
global mod_pass_fail_maxdiff;
%Run the C modulator
cmod = fmfsk_mod_c(Fs,Rs,bits);
%Set up and run the octave modulator
states.M = M;
states = fmfsk_init(Fs,Rs);
omod = fmfsk_mod(states,bits)';
dmod = cmod-omod;
pass = max(dmod)<(mod_pass_fail_maxdiff*length(dmod));
if !pass
printf('Mod failed test %s!\n',tname);
end
endfunction
% Random bit modulator test
% Pass random bits through the modulators and compare
function pass = test_mod_fdvbcfg_randbits
rand('state',1);
randn('state',1);
bits = rand(1,19200)>.5;
[dmod,cmod,omod,pass] = fmfsk_mod_test(48000,2400,bits,"mod fdvbcfg randbits");
if(!pass)
figure(1)
plot(dmod)
title("Difference between octave and C mod impl");
end
endfunction
% run_sim copypasted from fsk_horus.m
% simulation of tx and rx side, add noise, channel impairments ----------------------
function stats = tfmfsk_run_sim(EbNodB,timing_offset=0,de=0,of=0,hpf=0,df=0,M=2)
global print_verbose;
test_frame_mode = 2;
frames = 70;
%EbNodB = 3;
%timing_offset = 0.0; % see resample() for clock offset below
%fading = 0; % modulates tx power at 2Hz with 20dB fade depth,
% to simulate balloon rotating at end of mission
more off
rand('state',1);
randn('state',1);
Fs = 48000;
Rbit = 2400;
% ----------------------------------------------------------------------
fm_states.pre_emp = 0;
fm_states.de_emp = de;
fm_states.Ts = Fs/(Rbit*2);
fm_states.Fs = Fs;
fm_states.fc = Fs/4;
fm_states.fm_max = 3E3;
fm_states.fd = 5E3;
fm_states.output_filter = of;
fm_states = analog_fm_init(fm_states);
% ----------------------------------------------------------------------
states = fmfsk_init(Fs,Rbit);
states.verbose = 0x1;
Rs = states.Rs;
nsym = states.nsym;
Fs = states.Fs;
nbit = states.nbit;
EbNo = 10^(EbNodB/10);
variance = states.Fs/(states.Rb*EbNo);
% set up tx signal with payload bits based on test mode
if test_frame_mode == 1
% test frame of bits, which we repeat for convenience when BER testing
test_frame = round(rand(1, states.nbit));
tx_bits = [];
for i=1:frames+1
tx_bits = [tx_bits test_frame];
end
end
if test_frame_mode == 2
% random bits, just to make sure sync algs work on random data
tx_bits = round(rand(1, states.nbit*(frames+1)));
end
if test_frame_mode == 3
% repeating sequence of all symbols
% great for initial test of demod if nothing else works,
% look for this pattern in rx_bits
% ...10101...
tx_bits = zeros(1, states.nbit*(frames+1));
tx_bits(1:2:length(tx_bits)) = 1;
end
[b, a] = cheby1(4, 1, 300/Fs, 'high'); % 300Hz HPF to simulate FM radios
tx_pmod = fmfsk_mod(states, tx_bits);
tx = analog_fm_mod(fm_states, tx_pmod);
if(timing_offset>0)
tx = resample(tx, 2000, 1999); % simulated 1000ppm sample clock offset
end
%Add frequency drift
fdrift = df/Fs;
fshift = 2*pi*fdrift*(1:length(tx));
fshift = exp(j*(fshift.^2));
tx = tx.*fshift;
noise = sqrt(variance)*randn(length(tx),1);
rx = tx + noise';
%Demod by analog fm
rx = analog_fm_demod(fm_states, rx);
%High-pass filter to simulate the FM radios
if hpf>0
rx = filter(b,a,rx);
end
timing_offset_samples = round(timing_offset*states.Ts);
st = 1 + timing_offset_samples;
rx_bits_buf = zeros(1,2*nbit);
test_name = sprintf("tfmfsk run sim EbNodB:%d frames:%d timing_offset:%d df:%d",EbNodB,frames,timing_offset,df);
tstats = fmfsk_demod_xt(Fs,Rbit,rx',test_name,M);
pass = tstats.pass;
obits = tstats.obits;
cbits = tstats.cbits;
% Figure out BER of octave and C modems
bitcnt = length(tx_bits);
rx_bits = obits;
ber = 1;
ox = 1;
for offset = (1:400)
nerr = sum(xor(rx_bits(offset:length(rx_bits)),tx_bits(1:length(rx_bits)+1-offset)));
bern = nerr/(bitcnt-offset);
if(bern < ber)
ox = offset;
best_nerr = nerr;
end
ber = min([ber bern]);
end
offset = ox;
bero = ber;
ber = 1;
rx_bits = cbits;
ox = 1;
for offset = (1:400)
nerr = sum(xor(rx_bits(offset:length(rx_bits)),tx_bits(1:length(rx_bits)+1-offset)));
bern = nerr/(bitcnt-offset);
if(bern < ber)
ox = offset;
best_nerr = nerr;
end
ber = min([ber bern]);
end
offset = ox;
berc = ber;
if print_verbose == 1
printf("C BER %f in test %s\n",berc,test_name);
printf("Oct BER %f in test %s\n",bero,test_name);
end
stats.berc = berc;
stats.bero = bero;
stats.name = test_name;
% non-coherent BER theory calculation
% It was complicated, so I broke it up
ms = 2;
ns = (1:ms-1);
as = (-1).^(ns+1);
bs = (as./(ns+1));
cs = ((ms-1)./ns);
ds = ns.*log2(ms);
es = ns+1;
fs = exp( -(ds./es)*EbNo );
thrncoh = ((ms/2)/(ms-1)) * sum(bs.*((ms-1)./ns).*exp( -(ds./es)*EbNo ));
stats.thrncoh = thrncoh;
stats.pass = pass;
endfunction
function pass = ebno_battery_test(timing_offset,drift,hpf,deemp,outfilt)
global print_verbose;
%Range of EbNodB over which to test
ebnodbrange = (8:2:20);
ebnodbs = length(ebnodbrange);
%Replication of other parameters for parcellfun
timingv = repmat(timing_offset ,1,ebnodbs);
driftv = repmat(drift ,1,ebnodbs);
hpfv = repmat(hpf ,1,ebnodbs);
deempv = repmat(deemp ,1,ebnodbs);
outfv = repmat(outfilt ,1,ebnodbs);
statv = pararrayfun(floor(.75*nproc()),@tfmfsk_run_sim,ebnodbrange,timingv,deempv,outfv,hpfv,driftv);
%statv = arrayfun(@tfsk_run_sim,modev,ebnodbrange,timingv,fadingv,dfv,dav,mv);
passv = zeros(1,length(statv));
for ii=(1:length(statv))
passv(ii)=statv(ii).pass;
if statv(ii).pass
printf("Test %s passed\n",statv(ii).name);
else
printf("Test %s failed\n",statv(ii).name);
end
end
%All pass flags are '1'
pass = sum(passv)>=length(passv);
%and no tests died
pass = pass && length(passv)==ebnodbs;
passv;
assert(pass)
endfunction
%Test with and without sample clock offset
function pass = test_timing_var(drift,hpf,deemp,outfilt)
pass = ebno_battery_test(1,drift,hpf,deemp,outfilt)
assert(pass)
pass = ebno_battery_test(0,drift,hpf,deemp,outfilt)
assert(pass)
endfunction
%Test with and without 1 Hz/S freq drift
function pass = test_drift_var(hpf,deemp,outfilt)
pass = test_timing_var(1,hpf,deemp,outfilt)
assert(pass)
pass = pass && test_timing_var(0,hpf,deemp,outfilt)
assert(pass)
endfunction
function pass = test_fmfsk_battery()
pass = test_mod_fdvbcfg_randbits;
assert(pass)
pass = pass && test_drift_var(1,1,1);
assert(pass)
if pass
printf("***** All tests passed! *****\n");
end
endfunction
function plot_fmfsk_bers(M=2)
%Range of EbNodB over which to test
ebnodbrange = (8:14);
ebnodbs = length(ebnodbrange);
%Replication of other parameters for parcellfun
%Turn on all of the impairments
timingv = repmat(1 ,1,ebnodbs);
driftv = repmat(1 ,1,ebnodbs);
hpfv = repmat(1 ,1,ebnodbs);
deempv = repmat(1 ,1,ebnodbs);
outfv = repmat(1 ,1,ebnodbs);
statv = pararrayfun(nproc(),@tfmfsk_run_sim,ebnodbrange,timingv,deempv,outfv,hpfv,driftv);
%statv = arrayfun(@tfsk_run_sim,modev,ebnodbrange,timingv,fadingv,dfv,dav,Mv);
for ii = (1:length(statv))
stat = statv(ii);
berc(ii)=stat.berc;
bero(ii)=stat.bero;
berinc(ii)=stat.thrncoh;
end
clf;
figure(M)
semilogy(ebnodbrange, berinc,sprintf('r;2FSK non-coherent theory;',M))
hold on;
semilogy(ebnodbrange, bero ,sprintf('g;Octave ME-FM-FSK Demod;',M))
semilogy(ebnodbrange, berc,sprintf('v;C ME-FM-FSK Demod;',M))
hold off;
grid("minor");
axis([min(ebnodbrange) max(ebnodbrange) 1E-5 1])
legend("boxoff");
xlabel("Eb/No (dB)");
ylabel("Bit Error Rate (BER)")
endfunction
xpass = test_fmfsk_battery
plot_fmfsk_bers(2)
if xpass
printf("***** All tests passed! *****\n");
else
printf("***** Some test failed! Look back through output to find failed test *****\n");
end