一、获取代码方式
获取代码方式1：
完整代码已上传我的资源： 【数字信号调制】基于matlab GUI QPSK调制+解调【含Matlab源码 646期】
获取代码方式2：
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备注：订阅紫极神光博客付费专栏，可免费获得1份代码（有效期为订阅日起，三天内有效）；
二、QPSK简介
1 调制模型
与QPSK相比，OQPSk调制方式在复数通道Q通道中，插入了一个比特的时延Tb。
2.优点
OQPSK能够把180度的相移变化变成两个π /2的相位变化，因此相轨道远离了原点
3 解调
因为调制时Q路进行了延时，所以解调时I路进行延时
三、部分源代码
function varargout = GUI_QPSK(varargin)% GUI_QPSK MATLAB code for GUI_QPSK.fig%GUI_QPSK, by itself, creates a new GUI_QPSK or raises the existing%singleton*.%%H = GUI_QPSK returns the handle to a new GUI_QPSK or the handle to%the existing singleton*.%%GUI_QPSK('CALLBACK',hObject,eventData,handles,...) calls the local%function named CALLBACK in GUI_QPSK.M with the given input arguments.%%GUI_QPSK('Property','Value',...) creates a new GUI_QPSK or raises the%existing singleton*. Starting from the left, property value pairs are%applied to the GUI before GUI_QPSK_OpeningFcn gets called. An%unrecognized property name or invalid value makes property application%stop. All inputs are passed to GUI_QPSK_OpeningFcn via varargin.%%*See GUI Options on GUIDE's Tools menu. Choose "GUI allows only one%instance to run (singleton)".%% See also: GUIDE, GUIDATA, GUIHANDLES% Edit the above text to modify the response to help GUI_QPSK% Last Modified by GUIDE v2.5 03-Dec- 20:37:56% Begin initialization code - DO NOT EDITgui_Singleton = 1;gui_State = struct('gui_Name', mfilename, ...'gui_Singleton', gui_Singleton, ...'gui_OpeningFcn', @GUI_QPSK_OpeningFcn, ...'gui_OutputFcn', @GUI_QPSK_OutputFcn, ...'gui_LayoutFcn', [] , ...'gui_Callback', []);if nargin && ischar(varargin{1})gui_State.gui_Callback = str2func(varargin{1});endif nargout[varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});elsegui_mainfcn(gui_State, varargin{:});end% End initialization code - DO NOT EDIT% --- Executes just before GUI_QPSK is made visible.function GUI_QPSK_OpeningFcn(hObject, eventdata, handles, varargin)% This function has no output args, see OutputFcn.% hObject handle to figure% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)% varargin command line arguments to GUI_QPSK (see VARARGIN)% Choose default command line output for GUI_QPSKhandles.output = hObject;s=round(rand(1,100)); %生成二进制基带数据并画出基带信号图N=1:100;%figure(1);subplot(311);stem(N,s);title('基带信号');grid on;Ps=1;M=4; %QPSK星座图d=sqrt(Ps)*sin(pi/M);A=[1+1*i,-1+1*i,-1-1*i,1-1*i]*d;%subplot(312);scatter(real(A),imag(A),'filled');title('QPSK星座图');hold on;theta=0:pi/100:2*pi;x=cos(theta);y=sin(theta);%plot(x,y);grid on; Maptable=[0 0;0 1;1 1;1 0]; %QPSK格雷码比特映射 for j=1:2:100for m=1:Mif isequal(s(j:j+1),Maptable(m,:)) Qu((j+1)/2)= (2*m-1)*pi/4;x((j+1)/2)=A(m);breakendendend%基带数据s携带的信息映射到X[n] Am=1; %载波调制T=0.0001; fc=6/T;Smpl=1000;deltaT=T/Smpl; %连续时间离散化间隔Ns=5; %画出Ns个符号的波形t=deltaT:deltaT:Ns*T; %离散时间序列for j=1:Nsindex=(j-1)*Smpl+1:j*Smpl; %第i个符号对应的离散时间序号g(index)=1; %矩形脉冲成型X(index)=Am*g(index).*cos(2*pi*fc*t(index)+Qu(ceil(index/100.01))); %载波调制信号end%subplot(313);plot(t,X);title('QPSK调制信号波形');SNR_dB=15; %定义信噪比SNR=10^(SNR_dB/10); %定义线性信噪比Ps=1;%发射功率Pn=Ps/SNR; %噪声方差x=x(1:50);z=sqrt(Pn/2)*(randn(size(x))+randn(size(x))*i); %生成白噪声h=1; %AWGN信道下，信道增益h=1y=h*x+z; %基带接受信号%figure(2);subplot(211);scatter(real(y(1:10)),imag(y(1:10)),'filled'); %y的星座图title('QPSK接收星座图');for j=1:length(y) Dist=abs(y(j)-A); %第j个接受信号与各星座图点的距离[~,Index]=min(Dist);%找到距离最近的点x_est(j)=A(Index); %得到发射调制信号的估计s_est(2*j-1:2*j)=Maptable(Index,:); %得到比特数据的估计endW=1:100;%subplot(212);stem(W,s_est);title('QPSK解调后信号');for n=1:25Pe_t(n)=2*sqrt(2)/4*erfc(sqrt(2*n)*sin(pi/M))-sqrt(2)/4*erfc(sqrt(2*n)*sin(pi/M))* sqrt(2)/4*erfc(sqrt(2*n)*sin(pi/M));Pb_t(n)=0.5*Pe_t(n);endPESUM=0;PBSUM=0for n=1:25for m=1:1000SNR=n;Ps=1; Pn=Ps/SNR;z=sqrt(Pn/2)*(randn(size(x))+randn(size(x))*i);h=1;y=h*x+z;for j=1:length(y)Dist=abs(y(j)-A);[~,Index]=min(Dist);x_est(j)=A(Index);s_est(2*j-1:2*j)=Maptable(Index,:);endfor k=1:100if(s(k)+s_est(k)==1)PBSUM=PBSUM+1;endendfor k1=1:50if isequal(x(k1),x_est(k1))PESUM=PESUM+0;elsePESUM=PESUM+1;endendendPb(n)=PBSUM/1000/100;Pe(n)=PESUM/1000/50;PBSUM=0;PESUM=0;endSNRX=1:25;%figure(3);plot(SNRX,Pb); hold on;plot(SNRX,Pe);scatter(SNRX,Pe_t);scatter(SNRX,Pb_t, 'filled');%xlabel('信噪比 SNR(r/dB)');title('AWGN信道下误码率与误符号率曲线'); axis([1 25 0 1])；grid on;hold off;H=sqrt(1/2)*(randn+i*randn);Y=H*x+z;%figure(4);subplot(211);scatter(real(Y(1:10)),imag(Y(1:10)),'filled');title('4PSK信道均衡前星座图');Y1=Y/H;%subplot(212);scatter(real(Y1(1:10)),imag(Y1(1:10)),'filled');title('4PSK信道均衡后星座图');PESUM1=0;PBSUM1=0for n=1:25for m=1:1000SNR=n;Ps=1; Pn=Ps/SNR;z=sqrt(Pn/2)*(randn(size(x))+randn(size(x))*i);Y1=(H*x+z)/H;for j=1:length(Y1)Dist=abs(Y1(j)-A);[~,Index]=min(Dist);x_est1(j)=A(Index);s_est1(2*j-1:2*j)=Maptable(Index,:);endfor k=1:100if(s(k)+s_est1(k)==1)PBSUM1=PBSUM1+1;endendfor k1=1:50if isequal(x(k1),x_est1(k1))PESUM1=PESUM1+0;elsePESUM1=PESUM1+1;end
四、运行结果
五、matlab版本及参考文献
1 matlab版本
a
2 参考文献
[1] 沈再阳.精通MATLAB信号处理[M].清华大学出版社，.
[2]高宝建,彭进业,王琳,潘建寿.信号与系统——使用MATLAB分析与实现[M].清华大学出版社，.
[3]王文光,魏少明,任欣.信号处理与系统分析的MATLAB实现[M].电子工业出版社，.
