基于matlab的ofdm通信系统仿真设计代码

以下是一个简单的基于MATLAB的OFDM通信系统仿真设计代码。它包括了OFDM信号的生成、加窗、IFFT、添加循环前缀、并行传输、接收端的循环前缀删除、FFT、解调、信道模拟和误码率计算。

clear all;
close all;
clc;

%% OFDM参数设置
N = 64;                 % 子载波数量
cp_len = 16;            % 循环前缀长度
data_len = N - cp_len;  % 数据长度
num_bits = 1000000;     % 要传输的比特数
M = 16;                 % 星座大小
SNR = 20;               % 信噪比

%% 生成随机比特流
tx_bits = randi([0 1], num_bits, 1);

%% 星座调制
tx_symbols = qammod(tx_bits, M);

%% OFDM信号生成
num_ofdm_symbols = ceil(length(tx_symbols) / data_len);
tx_ofdm_symbols = zeros(num_ofdm_symbols, N);
for i = 1:num_ofdm_symbols
    start_idx = (i-1)*data_len + 1;
    end_idx = min(start_idx+data_len-1, length(tx_symbols));
    data = tx_symbols(start_idx:end_idx);
    if length(data) < data_len
        data(end+1:data_len) = 0;
    end
    ofdm_data = ifft(data, N);
    tx_ofdm_symbols(i, :) = [ofdm_data(N-cp_len+1:N) ofdm_data];
end

%% 添加高斯噪声
noise_var = 1 / (10^(SNR/10));
noise = sqrt(noise_var/2) * (randn(size(tx_ofdm_symbols)) + 1j*randn(size(tx_ofdm_symbols)));
rx_ofdm_symbols = tx_ofdm_symbols + noise;

%% OFDM信号解调
rx_symbols = zeros(num_ofdm_symbols*data_len, 1);
for i = 1:num_ofdm_symbols
    start_idx = (i-1)*N + 1;
    end_idx = i*N;
    ofdm_symbol = rx_ofdm_symbols(i, :);
    data = ofdm_symbol(cp_len+1:end);
    rx_symbols(start_idx:end_idx-cp_len) = fft(data, N);
end

%% 星座解调
rx_bits = qamdemod(rx_symbols, M);

%% 误码率计算
num_errors = sum(abs(tx_bits - rx_bits));
BER = num_errors / num_bits;
fprintf('误码率为：%e\n', BER);

上述代码仅仅是OFDM通信系统仿真中的一个简单例子，实际情况中需要根据需求做出相应的修改。