OFDM系统 ZF信道均衡matlab代码

以下是基于MATLAB的OFDM系统ZF信道均衡的代码：

% OFDM系统ZF信道均衡matlab代码
clc;
clear all;
close all;
N = 64; % 块大小
cp = 16; % 循环前缀长度
num_carriers = 48; % 子载波数量
num_bits = 10000; % 传输位数
num_blocks = ceil(num_bits/(num_carriers*N)); % 块数量
SNR = 20; % 信噪比
% 生成随机比特流
bits_tx = randi([0 1],1,num_bits);
% 调制为QPSK符号
symbols_tx = 1-2*reshape(bits_tx,2,length(bits_tx)/2)';
symbols_tx = symbols_tx(:,1)+1j*symbols_tx(:,2);
% 分组
blocks_tx = reshape(symbols_tx,N,num_blocks);
% DFT处理
blocks_dft = (1/sqrt(N))*fft(blocks_tx,N);
% 插入循环前缀
blocks_cp = [blocks_dft(end-cp+1:end,:);blocks_dft];
% 并行发送
signal_tx = reshape(blocks_cp,(N+cp)*num_blocks,1);
% 生成AWGN
noise = 1/sqrt(2*SNR)*randn(length(signal_tx),1)+1j*1/sqrt(2*SNR)*randn(length(signal_tx),1);
% 加入噪声
signal_rx = signal_tx + noise;
% 并行接收
blocks_rx = reshape(signal_rx,N+cp,num_blocks);
% 去除循环前缀
blocks_nocp = blocks_rx(cp+1:end,:);
% DFT处理
blocks_dft = (1/sqrt(N))*fft(blocks_nocp,N);
% 生成ZF均衡矩阵
channel = randn(num_carriers,1)+1j*randn(num_carriers,1);
H = (1/sqrt(2))*(randn(num_carriers,num_blocks)+1j*randn(num_carriers,num_blocks));
H_inv = pinv(H);
W = H_inv;
% 块处理
blocks_zf = zeros(num_carriers,num_blocks);
for i = 1:num_blocks
blocks_zf(:,i) = W*blocks_dft(:,i);
end
% IDFT处理
blocks_idft = sqrt(N)*ifft(blocks_zf,N);
% 去掉循环前缀
blocks_nocp = blocks_idft(cp+1:end,:);
% 串行发送
symbols_rx = reshape(blocks_nocp,num_bits/2,1);
% 解调为二进制比特流
bits_rx = zeros(num_bits,1);
bits_rx(1:2:end) = real(symbols_rx)<0;
bits_rx(2:2:end) = imag(symbols_rx)<0;
% 计算误码率
num_errors = sum(xor(bits_tx,bits_rx));
ber = num_errors/num_bits;
disp(['误码率为: ',num2str(ber)]);