Matlab仿真ACO-OFDM信号发送与接收

%E:\大学课件&科学浏览器\大三下\光纤通信\光纤实验\ACO OFDM clc; clear all ; global N_IFFT; global N_sc; N_IFFT=64;%IFFT点数 N_sc=128;%有效数据的子载波数 BitperSymbol=4;%每符号的比特数 DataSymlength=256;%传输的符号数 % Data_Bitlength=DataSymlength*N_sc*BitperSymbol; N_cp=16;%循环前缀的个数 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %产生数据信号(X_Data,Y_Data)，round四舍五入取整 X_BitSource=round(rand(1,DataSymlength*BitperSymbol*N_sc)); %131072 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %串并变换，每一行是一个子载波 X_input=reshape(X_BitSource,N_sc,[]); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %M-QAM调制 %SymbolOrder = Binary时 %0 4 8 12 %1 5 9 13 %2 6 10 14 %3 7 11 15 hI = modem.qammod('M',2^BitperSymbol, 'PhaseOffset', 0, 'SymbolOrder','Binary', 'InputType', 'bit'); X_Data = modulate(hI,X_input); figure(1); plot(X_Data,'*r');title('16QAM调制后的X-Data'); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %矩阵调整 X1_zero=X_Data; X1_zero_half=X1_zero(1:N_sc/8,:); %X路数据的一半 %奇数子载波上数据置0 for k=1:N_sc/2^BitperSymbol X1_zero_half(2*k-1,1:DataSymlength*BitperSymbol)=zeros(1,DataSymlength*BitperSymbol); end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %Hermitian对称,关于第17行共轭对称 X1_zero_j=conj(X1_zero_half); %求共轭 %初始化后半段信号 X1_zero_j_z=zeros(N_sc/8,DataSymlength*BitperSymbol); for i = 1:N_sc/16 k=(N_sc/16+1)-i; X1_zero_j_z(2*i,1:DataSymlength*BitperSymbol) = X1_zero_j(2*k,1:DataSymlength*BitperSymbol); end X1_zero = vertcat(X1_zero_half,X1_zero_j_z); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %ifft变换，结果为实数 X1_ifft_output=ifft(X1_zero); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %零值处限幅，小于0的置0 X1_ifft_output_x=X1_ifft_output; X1_ifft_output_x(find(X1_ifft_output<0))=0; figure(2); subplot(2,1,1); stem(X1_ifft_output,'r.');title('限幅前X1'); subplot(2,1,2); stem(X1_ifft_output_x,'r.');title('限幅后X1'); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %加cp %头部加cp X1_cp=vertcat(X1_ifft_output_x(((end-N_cp+1):end),:),X1_ifft_output_x); figure(3); subplot(2,1,1); stem(X1_cp,'r');title('X1 with CP'); subplot(2,1,2); stem(X1_ifft_output_x,'r');title('X1 without CP'); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %并串变换 X1_OFDMSymbol=reshape(X1_cp.',[],1).'; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %高斯白噪声信道 RX1=awgn(X1_OFDMSymbol,30); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %串并变换，加了16行的CP RX1_para=reshape(RX1,[],N_sc/4+N_cp).'; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %去掉CP，去掉前16行，剩下的是数据 RX1_cutCP=RX1_para(N_cp+1:N_cp+N_sc/4, : ); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %FFT运算 RX1_QAMSymbol=fft(RX1_cutCP); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %逆限幅 RX1_QAMSymbol_2=2*RX1_QAMSymbol; RX1_QAMSymbol_2_z=RX1_QAMSymbol_2; for i=1:16; RX1_QAMSymbol_2_z((2*i)-1,:)=X_Data((2*i)-1,:); %奇数位恢复 end figure(4); plot(RX1_QAMSymbol_2_z,'r.');title('FFT后RX1'); axis([-4 4 -4 4]); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % %解码 % DX1_Bit=zeros(N_sc,DataSymlength*BitperSymbol); % % for i=1:32 % for j=1:1024 % if real(RX1_QAMSymbol_2_z(i,j)) > 2 && imag(RX1_QAMSymbol_2_z(i,j)) > 2 %1100 % DX1_Bit(BitperSymbol*(i-1)+1,j) = 1; % DX1_Bit(BitperSymbol*(i-1)+2,j) = 1; % DX1_Bit(BitperSymbol*(i-1)+3,j) = 0; % DX1_Bit(BitperSymbol*(i-1)+4,j) = 0; % end % if real(RX1_QAMSymbol_2_z(i,j)) > 2 && imag(RX1_QAMSymbol_2_z(i,j)) < 2 && imag(RX1_QAMSymbol_2_z(i,j)) > 0 %1101 % DX1_Bit(BitperSymbol*(i-1)+1,j) = 1; % DX1_Bit(BitperSymbol*(i-1)+2,j) = 1; % DX1_Bit(BitperSymbol*(i-1)+3,j) = 0; % DX1_Bit(BitperSymbol*(i-1)+4,j) = 1; % end % end % end % DX1_Bit=QAM_decoder(RX1_QAMSymbol_2_z,BitperSymbol); % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % %并串变换 % DX1_Bit_chuan=reshape(DX1_Bit.',1,[]); % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % %BER计算 % X_input_ceshi=X_input(1:128,:); % DX1_Bit_ceshi=DX1_Bit(1:128,:); % start_bit=BitperSymbol*N_sc*0+1; % last_bit=BitperSymbol*DataSymlength*N_sc/8; % X1_BER=BER_Compution(DX1_Bit_ceshi(start_bit:last_bit),X_input_ceshi(start_bit:last_bit)); % % disp([' ']); % disp(['=========>> X1_BER=',num2str(X1_BER),'; Y1_BER=',num2str(Y1_BER)]); % disp([' BER=',num2str(X1_BER)]); % disp('_______________________________________'); %