基于matlab实现 pam重建信号观测 给出简略代码

以下是一个基于MATLAB的PAM重建信号观测的简略代码：

% 定义参数和常量
T = 0.1;
Ts = 0.01;
A = 1;
M = 4;

% 生成随机数字
bits = randi([0, M-1], 1, 100);

% 将数字调制到脉冲上
t = 0:Ts:T;
p = zeros(1, length(t));
for i = 1:length(bits)
    if bits(i) == 0
        p = [p zeros(1, length(t))];
    else
        p = [p A*ones(1, length(t))];
    end
end

% 重建信号观测
y = zeros(1, length(p));
for i = 1:length(p)
    if mod(i-1, length(t)) == 0
        y(i) = p(i);
    else
        y(i) = 0;
    end
end

% 添加高斯白噪声
SNR = 10;
sigma = sqrt(A^2*Ts/(2*log2(M)*10^(SNR/10)));
n = sigma*randn(1, length(y));
x = y + n;

% 解调数字信号
demod_bits = zeros(1, length(bits));
for i = 1:length(bits)
    sum_x = sum(x((i-1)*length(t)+1:i*length(t)));
    if sum_x > 0.5*A*length(t)
        demod_bits(i) = 1;
    else
        demod_bits(i) = 0;
    end
end

% 计算误码率
error_bits = sum(bits ~= demod_bits);
error_rate = error_bits / length(bits);

以上代码仅供参考，具体实现可能需要根据具体情况进行调整。