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function sim_state = SimulateMod( sim_param, sim_state, code_param )
% SimulateMod runs a single coded/uncoded modulation simulation scenario
%
% The calling syntax is:
% sim_state = SimulateMod( sim_param, sim_state )
%
% sim_param = A structure containing simulation parameters.
% sim_state = A structure containing the simulation state.
% code_param = A structure contining derived information.
% Note: See readme.txt for a description of the structure formats.
%
% Copyright (C) 2005-2007, Matthew C. Valenti
%
% Last updated on Dec. 23, 2007
%
% Function SimulateMod is part of the Iterative Solutions Coded Modulation
% Library (ISCML).
%
% The Iterative Solutions Coded Modulation Library is free software;
% you can redistribute it and/or modify it under the terms of
% the GNU Lesser General Public License as published by the
% Free Software Foundation; either version 2.1 of the License,
% or (at your option) any later version.
%
% This library 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
% Lesser General Public License for more details.
%
% You should have received a copy of the GNU Lesser General Public
% License along with this library; if not, write to the Free Software
% Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
% create a random channel (BICM) interleaver
if (code_param.coded)
if ( sim_param.bicm > 0 )
code_param.bicm_interleaver = randperm(code_param.code_bits_per_frame)-1;
end
end
% determine Es/No
if ( sim_param.SNR_type(2) == 'b' ) % Eb/No
EbNo = 10.^(sim_param.SNR/10);
EsNo = EbNo*code_param.rate;
else % Es/No
EsNo = 10.^(sim_param.SNR/10);
end
% temporary filename
tempfile = 'tempsave.mat';
% FOR PROFILING RUNTIME
t0 = clock;
% simulate
for snrpoint = 1:length(EsNo)
fprintf( strcat( '\n', sim_param.SNR_type, ' = %f dB\n'), sim_param.SNR(snrpoint) );
current_time = fix(clock);
fprintf( 'Clock %2d:%2d:%2d\n', current_time(4), current_time(5), current_time(6) );
% loop until either there are enough trials or enough errors
while ( ( sim_state.trials( code_param.max_iterations, snrpoint ) < sim_param.max_trials( snrpoint ) )&( sim_state.frame_errors(code_param.max_iterations, snrpoint) < sim_param.max_frame_errors(snrpoint) ) )
% increment the trials counter
sim_state.trials(1:code_param.max_iterations, snrpoint) = sim_state.trials(1:code_param.max_iterations, snrpoint) + 1;
% generate random data
data = round( rand( 1, code_param.data_bits_per_frame ) );
% code and modulate
s = CmlEncode( data, sim_param, code_param );
% Put through the channel
symbol_likelihood = CmlChannel( s, sim_param, code_param, EsNo(snrpoint) );
if (code_param.outage == 0)
% Decode
[detected_data, errors] = CmlDecode( symbol_likelihood, data, sim_param, code_param );
% Echo an x if there was an error
if ( errors( code_param.max_iterations ) );
fprintf( 'x' );
end
% update frame error and bit error counters
sim_state.bit_errors( 1:code_param.max_iterations, snrpoint ) = sim_state.bit_errors( 1:code_param.max_iterations, snrpoint ) + errors;
sim_state.frame_errors( 1:code_param.max_iterations, snrpoint ) = sim_state.frame_errors( 1:code_param.max_iterations, snrpoint ) + (errors>0);
sim_state.BER(1:code_param.max_iterations, snrpoint) = sim_state.bit_errors(1:code_param.max_iterations, snrpoint)./sim_state.trials(1:code_param.max_iterations, snrpoint)/code_param.data_bits_per_frame;
sim_state.FER(1:code_param.max_iterations, snrpoint) = sim_state.frame_errors(1:code_param.max_iterations, snrpoint)./sim_state.trials(1:code_param.max_iterations, snrpoint);
% if uncoded, update symbol error rate, too.
if ~code_param.coded
if ( sim_param.mod_order > 2 )
error_positions = xor( detected_data(1:code_param.data_bits_per_frame), data );
% update symbol, frame, and bit error counters
sim_state.symbol_errors(snrpoint) = sim_state.symbol_errors( snrpoint) + sum( max( reshape( error_positions, code_param.bits_per_symbol, code_param.symbols_per_frame ),[],1 ) );
sim_state.SER(snrpoint) = sim_state.symbol_errors(snrpoint)/sim_state.trials(snrpoint)/code_param.symbols_per_frame;
else
sim_state.symbol_errors(snrpoint) = sim_state.bit_errors(snrpoint);
sim_state.SER(snrpoint) = sim_state.BER(snrpoint);
end
end
else
% determine capacity
if ( sim_param.bicm )
% BICM capacity
if (code_param.bpsk)
bit_likelihood = symbol_likelihood; % later this should be moved to Somap function
else
bit_likelihood = Somap( symbol_likelihood, sim_param.demod_type );
end
% BICM capacity (added log2(mod_order) on 12/23/07)
cap = log2(sim_param.mod_order)*Capacity( bit_likelihood, data );
else
% CM capacity (added log2(mod_order) on 12/23/07)
cap = log2(sim_param.mod_order)*Capacity( symbol_likelihood, data );
end
% compare to threshold and update FER counter
if ( cap < code_param.rate )
sim_state.frame_errors( 1, snrpoint ) = sim_state.frame_errors( 1, snrpoint ) + 1;
sim_state.FER(1, snrpoint) = sim_state.frame_errors(1, snrpoint)./sim_state.trials(1, snrpoint);
% Echo an x if there was an error
fprintf( 'x' );
end
end
% determine if it is time to save (either (1) last error, (2) last frame, or (3) once per save_rate)
condition1 = ( sim_state.frame_errors(code_param.max_iterations, snrpoint) == sim_param.max_frame_errors(snrpoint) );
condition2 = ( sim_state.trials( code_param.max_iterations, snrpoint ) == sim_param.max_trials( snrpoint ) );
condition3 = ~mod( sim_state.trials(code_param.max_iterations, snrpoint),sim_param.save_rate );
if ( condition1|condition2|condition3 )
% FOR PROFILING RUNTIME
% fprintf( '%f\n', etime(clock,t0) );
% t0=clock;
fprintf('.');
save_state = sim_state;
save_param = sim_param;
% Aded on April 22, 2006 in case system crashes during save
save( tempfile, code_param.save_flag, 'save_state', 'save_param');
% Store into local directory (if running locally)
if ( sim_param.compiled_mode )
copyfile( tempfile, sim_param.filename, 'f' );
end
movefile( tempfile, code_param.filename, 'f');
% redraw the BICM interleaver (so that it is uniform)
if (code_param.coded)
if ( sim_param.bicm > 0 )
code_param.bicm_interleaver = randperm(code_param.code_bits_per_frame)-1;
end
end
end
end
% halt if BER or FER is low enough
if ( ~code_param.outage & ( sim_state.BER(code_param.max_iterations, snrpoint) < sim_param.minBER ) )
% adjust max_iterations to be the last iteration that has not yet dropped below the BER threshold
% Logic has changed on 7-28-06
iteration_index = max( find( sim_state.BER(sim_param.plot_iterations,snrpoint) >= sim_param.minBER ) );
if isempty( iteration_index )
break;
else
code_param.max_iterations = sim_param.plot_iterations( iteration_index );
fprintf( '\nNumber of iterations = %d\n', code_param.max_iterations );
end
% elseif ( code_param.outage & ( sim_state.FER(code_param.max_iterations, snrpoint) < sim_param.minFER ) )
% break when the FER is low enough (changed on 12-31-07)
elseif ( sim_state.FER(code_param.max_iterations, snrpoint) < sim_param.minFER )
break;
end
end
fprintf( 'Simulation Complete\n' );
current_time = fix(clock);
fprintf( 'Clock %2d:%2d:%2d\n', current_time(4), current_time(5), current_time(6) );
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