esprit.m

这是一个用于语音信号处理的工具箱

%
% [f b]=esprit(x, P, nv)
% inputs
%	x : data sequence
%	P : number of poles
% 	nv : noise variance
% Modified by D. G. Childers


function [f, b, l] = esprit(x,P,nv)

P=2*P;
%The above is to account for the number of real signals, i.e.,
%there are two complex exponentials for each real signal.
ns=length(x);
[a, S, R]=correl(x, P);
W=nv*eye(size(R));
[E, D]=eig(R, W);
lambda=real(diag(D));
%k=length(lambda);
%k=1:k;
%plot(k,lambda);
%pause
M=10;
E=W*E(:,1:M);
[r, c]=size(E);
B=E(1:(r-1),:); BP=E(2:r,:);
[U,S,V]=svd([B BP]);
v12=V(1:M,(M+1):(2*M));
v22=V((M+1):(2*M),(M+1):(2*M));
lambda=eig(-v12*inv(v22));
f=[angle(lambda)];     % f is in units of radians from 0 to + - pi
b=[abs(lambda)];       % b is the magnitude of eigenvalue, approximately unity
l=lambda;