ovrlpsav.m

Digital signal processing using Matlab一書之範例程式

function [y] = ovrlpsav(x,h,N)
% Overlap-Save method of block convolution
% ----------------------------------------
% [y] = ovrlpsav(x,h,N)
% y = output sequence
% x = input sequence
% h = impulse response
% N = block length
%
Lenx = length(x); M = length(h);
M1 = M-1; L = N-M1;
h = [h zeros(1,N-M)];
%
x = [zeros(1,M1), x, zeros(1,N-1)]; % preappend (M-1) zeros
K = floor((Lenx+M1-1)/(L));         % # of blocks
Y = zeros(K+1,N);
% convolution with succesive blocks
for k=0:K
	xk = x(k*L+1:k*L+N);
	Y(k+1,:) = circonvt(xk,h,N);
end
Y = Y(:,M:N)';                      % discard the first (M-1) samples
y = (Y(:))';                        % assemble output