st_decoding.m

程序里面包含各部分算法仿真 可供参考和使用

function   st_decoded = st_decoding( Recv,channel_est ,N_subc,N_data_sym, N_Tx_ant, N_Rx_ant ,ST_Code, ...
    Idx_data,RateSTCoding,Modulation,hard_soft,LST_method,var_noise,ChannelEffectTest)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 空时解码和分集处理

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



st_decoded = zeros(N_subc,N_data_sym*RateSTCoding);

if ChannelEffectTest ~= 2
    
    % 如果没有发送分集(无空时编码)
    if N_Tx_ant == 1
        %H = squeeze(channel_est(:,1,:)); 
        % 1发多收最大比合并,如果是1收则此程序简化为单天线信道特性补偿
        st_decoded = MRC_combine(Recv,channel_est,Idx_data,N_data_sym,N_Rx_ant,N_subc);
        
        % 如果有发送分集
    else
        % 如果使用空时分组码
        if ST_Code == 1
            % 先对每条接收天线进行多发1收解码
            for n_r = 1:N_Rx_ant
                % 计算本帧的所有数据OFDM符号，需要分为多少组，送入STBC解码器
                loop_num = N_data_sym * RateSTCoding/N_Tx_ant ;
                for n = 1:loop_num
                    % 取出一组OFDM符号，为一次性送入空时解码器的符号组
                    R = Recv(:,(n-1)*N_Tx_ant/RateSTCoding + 1:n*N_Tx_ant/RateSTCoding,n_r);
                    % 取出对应的信道估计，对一条接收天线而言，需要发送天线数N_Tx_ant个信道响应
                    H = channel_est(:,(n-1)*N_Tx_ant/RateSTCoding + 1:n*N_Tx_ant/RateSTCoding,...
                        (n_r-1)*N_Tx_ant + 1:n_r*N_Tx_ant);
                    % 把一组OFDM符号和对应的信道响应，送入STBC解码器
                    decoded(:,(n-1)*N_Tx_ant + 1:n*N_Tx_ant,n_r) = stbc_decode(R,H,Idx_data,N_Tx_ant,N_subc);
                end
                % 再进行1发多收的合并.因为在stbc_decode中已经补偿了信道，所以此处为等增益合并
                st_decoded = st_decoded + decoded(:,:,n_r);  
            end
            st_decoded = st_decoded / N_Rx_ant;
            
            % 如果使用分层空时码
        elseif ST_Code == 2
            if Modulation == 2
                Cons = exp(j*[-3/4*pi 3/4*pi -1/4*pi 1/4*pi])/sqrt(N_Tx_ant); %  QPSK 调制映射关系
            elseif Modulation == 1
                Cons = [1 -1]/sqrt(N_Tx_ant);  %  BPSK 调制映射关系
            end
            for n = 1:N_data_sym
                % 取出一个OFDM符号以及其对应的（N_Tx_ant×N_Rx_ant）个信道响应
                Y = Recv(Idx_data,n,:);
                H = channel_est(Idx_data,n,:);
                % 送入BLAST空时解码器
                st_decoded(Idx_data,(n-1)*N_Tx_ant + 1:n*N_Tx_ant) = BLAST_decode(Y,H,Cons,hard_soft,LST_method,var_noise);
            end
        end
    end   
    
    
elseif ChannelEffectTest == 2
    
    st_decoded = Recv;
    
end