add_noise.m

OFDM系统仿真

function signal_out = add_noise(signal_in, SNR)

signal_power = signal_in*signal_in';
noise_power = signal_power*10^(-SNR/10);
len = length(signal_in);
noise = randn(1,len) + j*randn(1,len);
% noise = randn(1,len);
noise = noise*sqrt(noise_power/(noise*noise'));

signal_out = signal_in + noise;