基于Matlab实现BPSK、QPSK 和 16QAM 调制的循环前缀和直接序列扩频（Matlab代码实现）

     目录

💥1 概述

📚2 运行结果

🎉3 参考文献

👨‍💻4 Matlab代码

💥1 概述

该项目的目的是模拟不同调制方案（BPSK，QPSK，16QAM）的OFDM系统，无需编码，并使用（1/3）重复编码。

用于瑞利平坦衰落通道和频率选择性衰落通道。

📚2 运行结果

主函数部分代码：

clc, clear, close all
% Generate Random Bit stream bk
L = 1e6;
Eb_BPSK = 1;
bk = randi([0 1], 1, L);% Generate BPSK symbols based on the bit stream xk
xk = bk;
xk(xk == 1) = sqrt(Eb_BPSK);
xk(xk == 0) = -sqrt(Eb_BPSK);% Generate the complex channel vector and complex noise vector
N = 1:10;
N0 = Eb_BPSK ./ (10 .^ (N ./ 10)); % assumption
BER_v = zeros(1, 10);
SNR = zeros(1, 10);
for i = 1:10hr = normrnd(0, sqrt(0.5), 1, L);hi = normrnd(0, sqrt(0.5), 1, L);channel_BPSK = hr + 1j * hi;nc = normrnd(0, sqrt(N0(i) / 2), 1, L);ns = normrnd(0, sqrt(N0(i) / 2), 1, L);Noise_BPSK = nc + 1j * ns;% Compute the received symbol vector ykyk = channel_BPSK .* xk + Noise_BPSK;% Compensate for the channel gain at the receiverbk_telda = yk ./ channel_BPSK;                bk_telda(bk_telda > 0) = 1;bk_telda(bk_telda < 0) = 0;% Compute the bit-error rate (BER) for SNRBER = 0;for n = 1:Lif(bk_telda(n) ~= bk(n))BER = BER + 1;elsecontinue;endendBER_v(i) = BER / L;SNR(i) = 10 * log10(Eb_BPSK / N0(i));
end
semilogy(SNR, BER_v);
title('BER vs. SNR for BPSK before repetition');
xlabel('SNR (dB)');
ylabel('BER');
grid on;
hold on;% % Theoritacl Calculation
% BER_TH = zeros(length(N), 20);
% BER_TH(:, 1) = berfading(N, 'psk', 4, 1);
% semilogy(N, BER_TH)
% legend('Practical BER','Theoritical BER')%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Repeat the code
clc, clear
% Generate Random Bit stream bk
L = 1e6;
Eb_BPSK = 1;
bk = randi([0 1], 1, L);% Generate BPSK symbols based on the bit stream xk
xk = bk;
xk(xk == 1) = sqrt(Eb_BPSK);
xk(xk == 0) = -sqrt(Eb_BPSK);
xk_rep = repelem(xk, 3);
xk_ver = zeros(1, L);
BER_ver = zeros(1, 10);
% Generate the complex channel vector and complex noise vector
N = 1:10;
N0 = Eb_BPSK ./ (10 .^ (N ./ 10)); % assumption
SNR = zeros(1, 10);
for i = 1:10hr = normrnd(0, sqrt(0.5), 1, 3 * L);hi = normrnd(0, sqrt(0.5), 1, 3 * L);channel_BPSK = hr + 1j * hi;nc = normrnd(0, sqrt(N0(i) / 2), 1, 3 * L);ns = normrnd(0, sqrt(N0(i) / 2), 1, 3 * L);Noise_BPSK = nc + 1j * ns;% Compute the received symbol vector ykyk = channel_BPSK .* xk_rep + Noise_BPSK;% Compensate for the channel gain at the receiverbk_telda = yk ./ channel_BPSK;                bk_telda(bk_telda > 0) = 1;bk_telda(bk_telda < 0) = 0;% make the decsioncounter = 1;for j = 1:3:3*Lif((bk_telda(j) + bk_telda(j+1) + bk_telda(j+2)) > 1)xk_ver(counter) = 1;elsexk_ver(counter) = 0;endcounter = counter + 1;end

🎉3 参考文献

[1]于江,王春岭,沈刘平,张磊.扩频通信技术原理及其应用[J].中国无线电,2010(03):44-47.

部分理论引用网络文献，若有侵权联系博主删除。