用MATLAB2020b编程实现2DPSK信号的调制解调(相干检测+码反变换)

2DPSK调制：

clear all;
close all;

% 信号参数
fc = 10e3; % 载波频率
fs = 100e3; % 采样频率
T = 1/fs; % 采样时间间隔
Ts = 1/fc; % 符号时间间隔
N = fs/fc; % 每个符号的采样数

% 信息序列
data = [1 0 1 1 0 1 0 0 1 1 0 0 0 1 0 1];

% 2DPSK调制
phi = 0;
for i = 1:length(data)
    if data(i) == 1
        phi = phi + pi/2;
    else
        phi = phi - pi/2;
    end
    for j = 1:N
        x(j + (i-1)*N) = cos(2*pi*fc*(j-1)*T + phi);
    end
end

% 画图
t = 0:T:(length(data)*N-1)*T;
figure(1);
plot(t, x);
xlabel('时间/s');
ylabel('幅度');
title('2DPSK调制信号');

2DPSK解调：

clear all;
close all;

% 信号参数
fc = 10e3; % 载波频率
fs = 100e3; % 采样频率
T = 1/fs; % 采样时间间隔
Ts = 1/fc; % 符号时间间隔
N = fs/fc; % 每个符号的采样数

% 信息序列
data = [1 0 1 1 0 1 0 0 1 1 0 0 0 1 0 1];

% 2DPSK调制
phi = 0;
for i = 1:length(data)
    if data(i) == 1
        phi = phi + pi/2;
    else
        phi = phi - pi/2;
    end
    for j = 1:N
        x(j + (i-1)*N) = cos(2*pi*fc*(j-1)*T + phi);
    end
end

% 2DPSK解调
data_hat = zeros(1, length(data));
phi_hat = 0;
for i = 1:length(data)
    for j = 1:N
        y(j + (i-1)*N) = x(j + (i-1)*N)*cos(2*pi*fc*(j-1)*T + phi_hat) - sin(2*pi*fc*(j-1)*T + phi_hat)*imag(hilbert(x(j + (i-1)*N)));
    end
    if y(1 + (i-1)*N)*y(N + (i-1)*N) > 0
        data_hat(i) = 1;
    else
        data_hat(i) = 0;
    end
    if data_hat(i) == 1
        phi_hat = phi_hat + pi/2;
    else
        phi_hat = phi_hat - pi/2;
    end
end

% 误码率
num_error = sum(data ~= data_hat);
ber = num_error/length(data);
disp(['误码率为：', num2str(ber)]);

% 画图
t = 0:T:(length(data)*N-1)*T;
figure(1);
subplot(2,1,1);
plot(t, x);
xlabel('时间/s');
ylabel('幅度');
title('2DPSK调制信号');
subplot(2,1,2);
plot(t, y);
xlabel('时间/s');
ylabel('幅度');
title('2DPSK解调信号');