LTE下行链路matlab仿真代码

有关LTE下行链路的MATLAB仿真代码，以下是一个简单的示例：

% 参数设置
numSubcarriers = 12; % 子载波数量
numSymbols = 14; % 符号数量

% 生成随机的QPSK调制符号
data = randi([0 3], numSubcarriers, numSymbols);
qpskSymbols = qammod(data, 4, 'UnitAveragePower', true);

% OFDM调制
ofdmSymbols = ifft(qpskSymbols, numSubcarriers);

% 添加循环前缀
cpLength = 16;
ofdmSymbolsWithCP = [ofdmSymbols(end-(cpLength-1):end,:); ofdmSymbols];

% 并行传输
transmitSignal = ofdmSymbolsWithCP(:);

% 信道模型
channel = [0.9; 0.2; -0.1]; % 信道衰落系数
channelDelay = [0; 1; 3]; % 信道延迟
channelResponse = zeros(size(transmitSignal));
for i = 1:length(channel)
    channelResponse = channelResponse + ...
        filter(channel(i), [1 zeros(1, channelDelay(i))], transmitSignal);
end

% 加入高斯噪声
snr = 10; % 信噪比（dB）
receivedSignal = awgn(channelResponse, snr, 'measured');

% 移除循环前缀
receivedSignalWithoutCP = reshape(receivedSignal, numSubcarriers+cpLength, []);
receivedSignalWithoutCP = receivedSignalWithoutCP(cpLength+1:end,:);

% FFT解调
receivedSymbols = fft(receivedSignalWithoutCP, numSubcarriers);

% QPSK解调
receivedData = qamdemod(receivedSymbols, 4, 'UnitAveragePower', true);

% 计算误码率
errorRate = sum(sum(data ~= receivedData)) / (numSubcarriers * numSymbols);

disp(['误码率：', num2str(errorRate)]);

这段代码演示了一个简单的LTE下行链路传输的MATLAB仿真过程，包括QPSK调制、OFDM调制、添加/移除循环前缀、信道模型、高斯噪声、解调和误码率计算。你可以根据需要进行参数调整和功能扩展。