correlate2.m

频偏校正估频算法的实现

%%%%%%% -------------------------------------------------------------------
%%%%% -----相关法用于频率估计
%%%%% -----复相关、频率校正算法
% 
function fe = correlate2(x,fs,N)
% 
% x:输入数据
% fs:数据采样率
% N:FFT的点数
% fe:估计出的频率

delta_f = fs/N;
n = 0:N-1;   %%% ?

Z = fft(x,N);
P = abs(Z);
[Pm mi] = max(P);
fo = fs*(mi-1)/N

x = hilbert(x);   %%% x的解析信号

y = exp(-j*2*pi*fo*n./fs);   %%% 创建标准信号

z = x.*y;   %%% 相关

m = floor(N/2);   %%%???
g = sum(conj(z(1:N-m)).*z(m+1:N));

phase_g = angle(g);
delta_f = phase_g/(2*pi*m/fs)

fe = fo+delta_f;