dmusic.m

智能天线中的d music 算法

function dmusic(y,K,J)
% function dmusic(y,K,J)
% 
% 1D Damped MUSIC (DMUSIC) Algorithm
%
% y = signal
% K = # of damped sinusoids
% J = Subsample of prediction matrix
% 
% Ex:
%    dmusic(y,2,12);
% 
% References:
%     [1] Y. Li, J. Razavilar, and K. Liu, "A Super-Resolution Parameter
%         Estimation Algorithm for Multi- Dimensional NMR Spectroscopy," 
%         University of Maryland, College Park, MD 1995.
%
%     [2] E. Yilmaz and E. Dilaveroglu, "A Performance Analysis for DMUSIC,"
%         presented at 5TH International Conference on Electrical and
%         Electronics Engineering (ELECO 2007), Bursa, Turkey, 2007.
%
% Coded by: Kenneth John Faller II January 07, 2008
%
    warning('off','all');
    
    N = length(y)-1;
    
    if((N-J) < K || J < K)
        error('J has to be between K and N-K');
    end
    
    % Prediction Matrix
    H = hankel(y,1:J);
    A = H(1:J,:);
    
    % Singular Value Decomposition
    [U D V] = svd(A);    
    Vn = V(:,K+1:J);
    
    % MUSIC Spectrum    
    indB = 1;
    indW = 1;
    s = zeros(21,629);
    f = s;
    
    for B=0:0.05:1
        for w=0:0.01:2*pi
            s(indB,indW) = -B + j*w;
            r = 0;
            for indR=0:J-1
                n=indR+1;
                r(n,1) = exp(indR*s(indB,indW));
            end
            rt = r/norm(r);
            f(indB,indW) = real(1/((rt')*(conj(Vn)*(Vn.'))*rt));
            indW = indW + 1;
        end
        indW = 1;
        indB = indB + 1;
    end
    
    contour(imag(s),-real(s),f,20);
    xlabel('Frequency');
    ylabel('Damping Factor');