test_map.m

通信中常用的卷积码信道译码源码程序

clear all

% Few help variables
global Yes No
Yes = 1;No = 0;

LcOFlag = 0; 
MaxFlag = 0;

%% -- User defined parameters start -- %%

% Code generator vectors, in binary or octal form (see 'help
% poly2trellis' in Matlab for correct form). If empty, then specify
% 'Trellis.K' and 'Trellis.Rate' to use built-in codegenerators.
%
% $$$ Trellis.g = [1,0,0;
% $$$ 	     1,1,0;
% $$$ 	     1,1,1];
LData = 500;

TerminateF = Yes;			% default = 'Yes'
PunctureF = No;				% default = 'No'

% $$$ Trellis.g = [1,1,1;1,0,1];
%Trellis.g = [561,753];
Trellis.K = 7;
Trellis.Rate = 1/2;

% Number of input bits 
Trellis.k = 1;

% Generators in 'binary' or 'octal' form. Empty == 'binary'.
GenForm = ['octal'];			

EncType = 'non-recursive';                  % 'recursive' / 'non-recursive'
DecMetric = 'soft';                     % 'hard' / 'soft'

% Turbo-codes
iterations=1;

constellation = 'QPSK';

% Modulation mapping
switch upper(constellation)
 case 'BPSK'
  ModMap = [-1;1];
 case 'QPSK'
  ModMap = [-1-j; -1+j; 1-j; 1+j];	  % NOTE! Column vector!
 case '16-QAM'
  Lut_tmp = bin2dec(...
      ['1011'; '1001'; '0001'; '0011';
       '1010'; '1000'; '0000'; '0010';
       '1110'; '1100'; '0100'; '0110';
       '1111'; '1101'; '0101'; '0111']);

  Points_tmp = [-3+J*3;-1+J*3;1+J*3;3+J*3;
		-3+J*1;-1+J*1;1+J*1;3+J*1;
		-3-J*1;-1-J*1;1-J*1;3-J*1;
		-3-J*3;-1-J*3;1-J*3;3-J*3];

  ModMap(Lut_tmp+1) = Points_tmp;
  clear Lut_tmp Points_tmp;
end % switch constellation

Es = (ModMap'*ModMap)/length(ModMap);

BitsLut = double(dec2bin([0:length(ModMap)-1]))-48;
  
Trellis.ModLut = ModMap.';
Trellis.BitsLut = BitsLut;

% Number of bits / constellation point
Nbits = log2(length(ModMap));

% Signal-to-noise ratio in dB's
SNR = [0:1:3];

% Number of loops
loop_end = 20000;

%% -- User defined parameters end -- %%

% Initialise parameters
BER = zeros(length(SNR),loop_end);
time_tot = 0;

% Generate trellis
[Trellis, Lut, TerminateF, PunctureF] = ...
    trellis_gen(Trellis, EncType, DecMetric, ...
		GenForm, TerminateF, PunctureF);

Trellis.flag_3gpp = 0;

% For hard decision trellis decoding, initialise trellis
if strcmp(DecMetric,'hard')
  Trellis = trellis_init(Trellis, Lut);
end % if strcmp(DecMetric,

rand('state',sum(100*clock));
randn('state',sum(100*clock));

%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% -- SNR-loop begins -- %%
%%%%%%%%%%%%%%%%%%%%%%%%%%%

for s = 1:length(SNR)

  % if Es = 1, SNR = 1/N0 => N0 = 1/SNR, 
  snr_linear = 10^(SNR(s)/10);			
  % 2*sigma^2 = N0
  sigma_2 = Es/(2*snr_linear*Nbits*Trellis.Rate);
  N0 = 2*sigma_2;


  berrs_tot = 0;
  raw_berrs_tot = 0;
  
  for i1 = 1:loop_end

    time1 = clock;

    Data = round(rand(1,LData));
% $$$   Data = ones(1,LData);  
    
    %% -- Encoding -- %%
    
    [Data_coded,alpha_enc] = trellis_encoder(Data, Trellis, Lut, ...
					     TerminateF); 
    %% --          -- %%

    %% -- Modulation -- %%

    [Data_mod_tmp] = bb_modulation(Data_coded, ModMap);
    [dummy, alpha_channel] = sort(rand(1,length(Data_mod_tmp)));
    Data_mod = Data_mod_tmp(1,alpha_channel);

    %% --          -- %%  
    
    %% -- Channel -- %%

    awgn_tmp=randn(2,length(Data_mod))*sqrt(sigma_2);
    awgn=awgn_tmp(1,:)+sqrt(-1)*awgn_tmp(2,:);      %complex Gaussian noise
    fading_gains = ones(1,length(Data_mod));% + (1E-100)*sqrt(-1);  

    Data_ch = Data_mod.*fading_gains + awgn;

    %% --         -- %%
    
    %% -- Receiver -- %%
    
    Data_received = Data_ch; %(2*(Data_ch>0)-1)>0;  
    
    %% --          -- %%
    
    %% -- Decoding -- %%
    
    alpha_rsc = [1:length(Data)];	% dummy variable
    [Data_decoded,berrs,ferrs,raw_berrs,raw_ferrs] = ...
	turbo_rec(Data_received, fading_gains, 2*sigma_2, alpha_channel, ...
		  alpha_enc, alpha_rsc, iterations, Trellis, Lut, ModMap, ...
		  BitsLut, Data, PunctureF, LcOFlag, MaxFlag);
    
    
% $$$   Data_decoded = trellis_decoder(Data_received, Trellis, Lut, ...
% $$$ 				 alpha_channel, 'convolution');
    
    %% --          -- %%
    
    %% -- Error check -- %%
    
% $$$   BER(1,i1) = length(find(Data_decoded - Data)) / length(Data);
    
    %% --             -- %%
    time = etime(clock,time1);
    time_tot = time_tot + time;
    berrs_tot = berrs_tot + berrs;
    raw_berrs_tot = raw_berrs_tot + raw_berrs;    
    if ~mod(i1,1000)
      disp(sprintf(['SNR loop #%2.1fdB#, iteration %d finished in time' ...
		    ' %1.2fs'],SNR(s), i1, time_tot));
    end % if ~mod(i1,...
  end % for i1 = 1:loop_end

  total_ber(s) = berrs_tot/(length(Data_decoded)*loop_end)
  total_raw_ber(s) = raw_berrs_tot/(length(Data_decoded)*loop_end)

  disp(sprintf('SNR loop #%2.1fdB# finished in time %1.2fs', SNR(s), time_tot));
  save conv_own9_tmp.mat total_ber SNR time_tot

end % for s = 1:length(SNR)

disp(sprintf('Total time: %2.12f hours', time_tot/3600));

% Remove paths
eval(['rmpath ' Trellis.Path_list]);

SNR_raw = 10*log10(10.^(SNR./10)*Trellis.Rate);

save test_jari_K7.mat total_ber SNR time_tot SNR_raw total_raw_ber