【QSPK图像传输】基于QPSK的多用户图像无线传输matlab仿真

1.软件版本

matlab2013b

2.系统实现

算法流程如下：

 程序主题如下：

clc;
clear;
close all;
warning off;

addpath 'func\'
addpath 'func_sub\Spread_and_Channel\'
addpath 'func_sub\Channel_Est\'
addpath 'func_sub\Receiver\'

%读取图像源
%%
%图像源
filename1       = 'Images\32\1.jpg';
filename2       = 'Images\32\2.jpg';
filename3       = 'Images\32\3.jpg';
figure;
subplot(231);imshow(imread(filename1));title('User1');
subplot(232);imshow(imread(filename2));title('User2');
subplot(233);imshow(imread(filename3));title('User3');
P               = 32*32*3*8;
%将三个图像源转换为二进制数据
[bitsOut1,x,y]  = fImageSource(filename1,P);
[bitsOut2,x,y]  = fImageSource(filename2,P);
[bitsOut3,x,y]  = fImageSource(filename3,P);
databox         = 1024;

 

%产生扩频gold码
%用户一产生gold码
d         = 2;
shift     = [d,d+3,d+6]; 
[MSeq1]   = fMSeqGen([1 0 0 1 1]);
[MSeq2]   = fMSeqGen([1 1 0 0 1]);
%由两个M序列产生GOLD序列
GoldSeq1 = fGoldSeq(MSeq1,MSeq2,shift(1))';
GoldSeq1(find(GoldSeq1==0)) = -1;
GoldSeq2 = fGoldSeq(MSeq1,MSeq2,shift(2))';
GoldSeq2(find(GoldSeq2==0)) = -1;
GoldSeq3 = fGoldSeq(MSeq1,MSeq2,shift(3))';
GoldSeq3(find(GoldSeq3==0)) = -1;


Goldseqs = [GoldSeq1 GoldSeq2 GoldSeq3];

Gold_Num = length(GoldSeq1); 
J        = [zeros(1,(2*Gold_Num-1)) 0;eye(2*Gold_Num-1) zeros((2*Gold_Num-1),1)];
%调制初始参数
phi      = pi/4;
%定义信噪比
SNR      =  100;
%定义三个用户的信道信息，修改信道参数，即可完成task1,2,3的功能实现
%array
Array_Position = [0 0 0;
                  0 0 0; 
                  0 0 0; 
                  0 0 0; 
                  0 0 0];   
               
%每个用户的多径数,1表示无多径                             
Path_Num = [1 1 1]';
User_Num = length(Path_Num); 
%DOA：azimuth, elevation
DOA_User1= [20  0];
        
DOA_User2= [70  0];
DOA_User3= [120 0];
DOA      = [DOA_User1; DOA_User2; DOA_User3];
%Delay
Delay1 = [5]';
Delay2 = [8]';
Delay3 = [11]';
Delay  = [Delay1; Delay2; Delay3];
%fading
fading1 = [0.9];
       
fading2 = [0.6]';
fading3 = [0.5]';
Beta    = [fading1; fading2; fading3];

%每次发送64个bit，进行循环发送，模拟实际情况
for nframes = 1:P/databox
    fprintf('Now transmit...%d\n\n',nframes);
    
    bits1 = [0 0 bitsOut1(databox*(nframes-1)+1:databox*nframes) 0 0]';
    bits2 = [0 0 bitsOut2(databox*(nframes-1)+1:databox*nframes) 0 0]';
    bits3 = [0 0 bitsOut3(databox*(nframes-1)+1:databox*nframes) 0 0]';
    %QPSK,根据星座图进行映射
    QPSK1 =fDSQPSKModulator(bits1,Goldseqs(:,1),phi);
    QPSK2 =fDSQPSKModulator(bits2,Goldseqs(:,2),phi);
    QPSK3 =fDSQPSKModulator(bits3,Goldseqs(:,3),phi);
    %扩频处理
    All_Photo = [QPSK1 QPSK2 QPSK3];
    %扩频，信道处理                                       
    R_Channel = fChannel(Path_Num,All_Photo, DOA, Delay, Beta, Goldseqs, Array_Position, SNR);
    %信道估计
    [DOAest,Delayest] = fChannelEstimation(R_Channel,GoldSeq1,Array_Position,Path_Num(1));
    %接收机解扩
    R = func_Reciver(R_Channel,DOAest,Delayest,Array_Position,GoldSeq1,Path_Num(1));
    %De QPSK
    DeQPSK = fDSQPSKDemodulator(R,GoldSeq1,phi);
    %DeQPSK = Decoder(R, 'QPSK');
    %最后接收到的数据
    Final_Rec(databox*(nframes-1)+1:databox*nframes) = DeQPSK;
    %传输错误个数
    sum(abs(bits1(3:end-2)-DeQPSK'))
end

%图像还原
subplot(235);
I = fImageSink(Final_Rec,P,x,y);
title('The receive data of user1');

figure;
subplot(121);
plot(QPSK1,'o');
grid on
axis square;
subplot(122);
plot(R,'o');
axis square;
figure;
subplot(141);
imshow(imread(filename1));
subplot(142);
plot(QPSK1,'o');
grid on
axis square;
subplot(143);
plot(R,'o');
axis square;
subplot(144);
imshow(uint8(I));
axis square;

3.仿真过程

40db

20 db

0 db

-10db

A01-63