%
function omegahat = pisarenko(signal) %PISARENKO Find the Pisarenko frequency estimates of the signals % in each column of signal. % % omegahat = pisarenko(signal) % % [1] V. F. Pisarenko, "On the Estimation of Spectra by % Means of Non-linear Functions of the Covariance Matrix," % Geophys. J. Roy. astr. Soc., Vol. 28, pp. 511-531, 1972. % % [2] V. F. Pisarenko, ``The Retrieval of Harmonics from a % Covariance Function," Geophys. J. Roy. astr. Soc., % Vol. 33, pp. 347-366, 1973. % % $Id: pisarenko.m,v 1.2 1999/01/09 11:10:35 PeterK Exp PeterK $ % File: pisarenko.m % % Copyright (C) 1999 Peter J. Kootsookos % % This software provided under the GNU General Public Licence, which % is available from the website from which this file originated. For % a copy, write to the Free Software Foundation, Inc., 675 Mass Ave, % Cambridge, MA 02139, USA. %Type cast it to double. signal = double(signal); %-------------------------------------------------------- % Error condition checks [T,N] = size(signal); if any([T N]==0) error('pisarenko: zero size data not allowed.'); end; if T==1 signal = signal(:); [T,N] = size(signal); end; Rss1 = sum(signal(2:T,:).*signal(1:T-1,:)); Rss2 = sum(signal(3:T,:).*signal(1:T-2,:)); alpha = ( Rss2 + sqrt(Rss2.^2 + 8*Rss1.^2) ) ./ ( Rss1 + eps ) / 2; omegahat = acos(alpha/2); % Author: Peter J. Kootsookos (kootsoop@ieee.org) % % Based on: P.J. Kootsookos, S.J. Searle and B.G. Quinn, % "Frequency Estimation Algorithms," CRC for Robust and % Adaptive Systems Internal Report, June 1993. %