main1003.asv

放大转发协同通信的有关仿真代码

%Cooperative Diversity - Main Sequence
tic
% --------------
% Set Parameters
nr_of_iterations = 100;
SNR = [-8:2:8];
use_direct_link = 1;
use_relay = 1;
global statistic;
statistic = generate_statistic_structure;
global signal;
signal = generate_signal_structure;
channel = generate_channel_structure;%信道结构
%channel(1):源端到目的端  channel(2):源端到中继端   channel(3):中继到目的端
channel(1).attenuation(1).pattern = 'no';% 'no','Rayleigh'
%channel(1).attenuation(1).pattern = 'Rayleigh';% 'no','Rayleigh'
channel.attenuation.block_length = 1;
channel(2) = channel(1);
channel(3) = channel(1);
channel(1).attenuation.distance = 1;
channel(2).attenuation.distance = 1;
channel(3).attenuation.distance = 1;
crc_check=1;
rx = generate_rx_structure;%接收端结构
rx(1).combining_type = 'MRC'; %'ERC','FRC','SNRC','ESNRC','MRC'
rx(1).sd_weight = 1.0;
global relay;
relay = generate_relay_structure;
relay(1).mode = 'TURBOCC'; %'AF', 'DF','RCPC','TURB0CC','TURBO' 选择分集协议类型
coop_rate=1/2;
relay.magic_genie = 0;
relay(1).rx(1) = rx(1); % same beahaviour
% ---------------
% Start Simulation
BER = zeros(size(SNR));
for iSNR = 1:size(SNR,2)
    error_bit =zeros(1,nr_of_iterations);
    channel(1).noise(1).SNR = SNR(iSNR);
    channel(2).noise(1).SNR = SNR(iSNR)+10;
    channel(3).noise(1).SNR = SNR(iSNR);
    disp(['progress: ',int2str(iSNR),'/',int2str(size(SNR,2))])
% --------------
% Reset receiver
    rx = rx_reset(rx);
    relay.rx = rx_reset(relay.rx);
% -----------

    for it = 1:nr_of_iterations;   %迭代计算次数

         switch relay.mode
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
             case 'TURBOCC'
                 dec_alg = 1;                        % the decoding algorithm. (0:Log-MAP, 1:SOVA)  default 0)
                 niter = 5;                          % number of iterations for each frame
                 L_total = 130;                      %L_total = L_info + m; 
                 g = [ 1 1 1; 1 0 1 ];               % 生成矩阵
                 [n,K] = size(g); 
                 m = K - 1;                          % m=2
                 nstates = 2^m;                      % 4
                 puncture = 1;                       %unpuncture: 1, puncture:0 
                 rate = 1/(2+puncture);   
                 % Fading amplitude; a=1 in AWGN channel
                 a = 1; 
                 
                 x1 = round(rand(1, L_total-m-16));           % info. bits 信息比特112
                 CRC_CCITT = CRC_16(x1);
                 x =[x1,CRC_CCITT];                           %加上CRC 比特信息128
                 L_info = length(x);
                 input = x;
                 output1 = rsc_encode(g,input,1);              %经RSC1编码后的输出信息
                                 
                 transmit_symbol = output1;
                 signal(1).nr_of_bits = length(transmit_symbol);
                 signal.modulation_type = 'BPSK'; % 'BPSK', 'QPSK'
                 calculate_signal_parameter(transmit_symbol);   %准备发送信息modulate
                    if (use_direct_link == 1)
                        [channel(1), rx] = add_channel_effect(channel(1), rx,signal(1).symbol_sequence,1/3);   %S-D传输
                        rx = rx_correct_phaseshift(rx, channel(1).attenuation.phi);   %校正相位
                        rx.signal2analyse = real(rx.signal2analyse);    %取实部信息
                        y(1,:) = rx.signal2analyse(1:2:2*L_total);      %取系统位
                        y(2,:) = rx.signal2analyse(2:2:2*L_total);      %取RSC1校验位
                        %a = channel(1).attenuation.h_mag;
                    end
                    if (use_relay == 1)
                        [channel(2), relay.rx] = add_channel_effect(channel(2),relay.rx, signal(1).symbol_sequence,1/3);  %S-R传输
                        relay.rx =rx_correct_phaseshift(relay.rx,channel(2).attenuation.phi);
                        relay.rx.signal2analyse = real(relay.rx.signal2analyse);  %1*260
                        %y2(1,:) = relay.rx.signal2analyse(1:2:2*L_total)
                        qcode = quantiz(relay.rx.signal2analyse,[0.001,.1,.3,.5,.7,.9,.999]);   % 软判决
                        tblen = 48; delay = tblen; % Traceback length
                        add =zeros(1,2*delay);
                        qcode = [qcode,add];  %因为延时，末位补0
                        t = poly2trellis(3,[7 5],7); % Define trellis.                      
                        decoded = vitdec(qcode,t,tblen,'cont','soft',3); % Decode. 维特比译码1*130
                        err_RSC = sum(abs(decoded(delay+1:end-2) - x));   % 译码错误比特数                       
                        
                        y1(1,:) = decoded(delay+1:end);    % y: unpuncture output of encoder; y(1,:) has m bits more than input bits  
                        %检查CRC
                        crc_check = 1;
                        y2 = y1(1:L_total-m-16);
                        y1_CRC = CRC_16(y2);
                        if(((y1(L_total-m-15:L_total-m) - y1_CRC) ~=0) & (crc_check ~= 0) )
                            %S发送RSC2部份信息
                            y1(1,:) = output1(1:2:2*L_total);
                            [temp, alpha] = sort(rand(1,L_total));        % random interleaver mapping 随机交织映射
                            for i = 1:L_total
                                input1(1,i) = y1(1,alpha(i));     %alpha--index of interleaver
                            end
                            output2 = rsc_encode(g, input1(1,1:L_total), -1 );   %生成RSC2部份信息比特
                            %y(3,:) = output2(2:2:2*L_total);
                            calculate_signal_parameter(output2(2:2:2*L_total));           % 经过BPSK调制
                            %relay.signal2send = signal.symbol_sequence; 
                            [channel(1), rx] = add_channel_effect(channel(1), rx, signal.symbol_sequence,1/3);   
                            rx = rx_correct_phaseshift(rx,channel(1).attenuation.phi);
                            rx.signal2analyse = real(rx.signal2analyse);
                        else                      
                            [temp, alpha] = sort(rand(1,L_total));        % random interleaver mapping 随机交织映射
                            for i = 1:L_total
                                input1(1,i) = y1(1,alpha(i));     %alpha--index of interleaver
                            end
                            output2 = rsc_encode(g, input1(1,1:L_total), -1 );   %生成RSC2部份信息比特
                            %relay to destination
                            calculate_signal_parameter(output2(2:2:2*L_total));           % 经过BPSK调制 
                            relay.signal2send = signal.symbol_sequence; 
                            [channel(3), rx] = add_channel_effect(channel(3), rx,relay.signal2send,1/3);   %relay发送信息至receive
                            rx = rx_correct_phaseshift(rx,channel(3).attenuation.phi);
                            rx.signal2analyse = real(rx.signal2analyse);
                        end
                                                      
                        y(3,:) = rx.signal2analyse;
                        %receive_value =[receive_value;rx.signal2analyse];
                        % 删除器
                        if puncture > 0		% unpunctured
                            for i = 1:L_total
                                for j = 1:3
                                    en_output(1,3*(i-1)+j) = y(j,i); % put the 3 bits of the same colomn to a sequential outputs 1*390
                                end
                            end
                        else			% punctured into rate 1/2
                            for i=1:L_total
                                en_output(1,n*(i-1)+1) = y(1,i);
                                if rem(i,2)  % output check bits by turns    
                                    % odd check bits from RSC1
                                    en_output(1,n*i) = y(2,i);
                                else
                                    % even check bits from RSC2
                                    en_output(1,n*i) = y(3,i);   %1*260
                                end 
                            end  
                        end
                    end
                    yk = demultiplex(en_output,alpha,puncture);     %解复用
                    en = 10^(SNR(iSNR)/10);    % convert Eb/N0 from unit db to normal numbers
                    L_c = 4*a*en*rate; 	% reliability value of the channel
                    %sigma1 = 1/sqrt(2*rate*en); 	% standard deviation of AWGN noise
                    errs(1,1:niter) = zeros(1,niter);
                    nferr(1,1:niter) = zeros(1,niter);
                    % Scale the received bits      
                    rec_s = 0.5*L_c*yk;

                    % Initialize extrinsic information      
                    L_e(1:L_total) = zeros(1,L_total);
      
                    for iter = 1:niter
                    % Decoder one
                    % deinterleave the extrinsic information for first decoder   -yzh
                        L_a(alpha) = L_e;  % a priori info. 解交织
                        if dec_alg == 0
                            L_all = logmapo(rec_s(1,:), g, L_a, 1);  % complete info.
                        else   
                            L_all = sova0(rec_s(1,:), g, L_a, 1);  % complete info.
                        end   
                        L_e = L_all - 2*rec_s(1,1:2:2*L_total) - L_a;  % extrinsic info.
                    % Decoder two         
                        L_a = L_e(alpha);  % a priori info.交织
                        if dec_alg == 0
                            L_all = logmapo(rec_s(2,:), g, L_a, 2);  % complete info.  
                        else
                            L_all = sova0(rec_s(2,:), g, L_a, 2);  % complete info. 
                        end
                            L_e = L_all - 2*rec_s(2,1:2:2*L_total) - L_a;  % extrinsic info.        
                    % Estimate the info. bits        
                        xhat(alpha) = (sign(L_all)+1)/2;