ODCSK正交差分混沌键控的matlab仿真

% 扩频因子不同的情况下，BER与SNR的关系 clear,clc; N = [1, 3, 5, 7]; % 用户数 n = [3, 5, 7]; % 阶数 M = 2.^n; % 扩频因子 EbN0 = 0:30; % 信噪比[dB] L = 1e6; % 用户发送数据大小 b = sign(2*rand(max(N), L) - 1); y0 = 2*rand() - 1; for i = 1:length(M) x = chaos(M(i), y0); % 混沌序列 h = walsh(n(i)); % Hadamard矩阵 figure('name', ['扩频因子 M = ', num2str(M(i)), ' 时， 不同用户数下误码率随信噪比的变化曲线']); for j = 1:length(N) Eb = (M(i)*(N(j) + 1) / N(j)) * mean(x.^2); % 选择每个用户的walsh码 w = zeros(N(j), M(i)); index = randperm(M(i)); for m = 1:N(j) w(m, :) = h(index(m), :); end b0 = b(1:N(j), :); % 用户发送的数据 s = modulation(x, b0, w); BER = zeros(size(EbN0)); for k = 1:length(EbN0) SNR_liner = 10^(EbN0(k) / 10); sigma_noise = sqrt(Eb / (2*SNR_liner)); noise = normrnd(0, sigma_noise, size(s)); r = s + noise; b1 = demodulation(r, w); [row, col] = size(b0); BER(k) = sum(sum(abs(b1 - b0))) / (row * col); end semilogy(EbN0, BER); hold on; end grid on; axis([0 20 1e-5 1e0]); xlabel('Eb/N_0[dB]'); ylabel('BER'); legend('用户数为1', '用户数为3', '用户数为5', '用户数为7', 'location', 'southwest'); hold off; end