Matlab仿真ACO-OFDM信号发送与接收

1、首先，Matlab产生16QAM映射方式的OFDM符号，然后在产生ACO-OFDM信号。 2、在每个ACO-OFDM符号前添加循环前缀，然后编写ACO-OFDM信号发送接收程序。 3、信道使用高斯白噪声（AWGN）信道。 4、Matlab绘出时域ACO-OFDM信号，均衡后的接收信号的星座图。

%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_DataY_Data），round四舍五入取整
X_BitSource=round（rand（1DataSymlength*BitperSymbol*N_sc））;  %131072

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
%串并变换，每一行是一个子载波
X_input=reshape（X_BitSourceN_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（hIX_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-11:DataSymlength*BitperSymbol）=zeros（1DataSymlength*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/8DataSymlength*BitperSymbol）;

for i = 1:N_sc/16
    k=（N_sc/16+1）-i;
        X1_zero_j_z（2*i1:DataSymlength*BitperSymbol） = X1_zero_j（2*k1:DataSymlength*BitperSymbol）;
end  

X1_zero = vertcat（X1_zero_halfX1_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（211）;
stem（X1_ifft_output‘r.‘）;title（‘限幅前X1‘）;
subplot（212）;
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（211）;
stem（X1_cp‘r‘）;title（‘X1 with CP‘）;
subplot（212）;
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_OFDMSymbol30）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%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_scDataSymlength*BitperSymbol）;
% 
% for i=1:32
%     for j=1:1024
%         if real（RX1_QAMSymbol_2_z（ij）） > 2 && imag（RX1_QAMSymbol_2_z（ij）） > 2 %11

 属性            大小     日期    时间   名称
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     文件       4472  2018-06-05 15:07  ACO_OFDM.m

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