- refactored

2022-06-30 13:32:40 +02:00
parent 77cd5261b1
commit 776932e5d1
144 changed files with 0 additions and 38 deletions
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+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%                                                    %
+%            Fast LMS Algorithm                      %
+%                                                    %
+% Written By: Sundar Sankaran and A. A. (Louis) Beex %
+%             DSP Research Laboratory                %
+%             Dept. of Electrical and Comp. Engg     %
+%             Virginia Tech                          %
+%             Blacksburg VA 24061-0111               %
+%                                                    %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+randn('seed', 0) ;
+rand('seed', 0) ;
+
+NoOfData = 8000 ;	% Set no of data points used for training
+M = 32 ;		% Set the adaptive filter order
+
+Mu = 0.01 ;		% Set the step-size constant
+Gamma = 0.9 ;		% Forgetting factor
+Delta = 0.01 ;		% R_est initialized to Delta*I
+
+u = randn(NoOfData, 1) ;% Input assumed to be white
+h = rand(M, 1) ;	% System picked randomly
+d = filter(h, 1, u) ;	% Generate output (desired signal)
+
+% Initialize fast-lms
+
+W = zeros(2*M,1) ;
+p = Delta*ones(2*M,1) ;
+
+y = zeros(M, 1) ;
+e = zeros(M, 1) ;
+
+for k = 2 : floor(length(u)/M) - 1 ;
+
+	U = fft(u((k-1)*M:(k+1)*M-1)) ;
+	Y = ifft(U.*W) ;
+	y(k*M:(k+1)*M-1) = real(Y(M+1:2*M)) ;
+	
+	e(k*M:(k+1)*M-1) = d(k*M:(k+1)*M-1) - y(k*M:(k+1)*M-1) ;
+	E = fft([zeros(M,1); e(k*M:(k+1)*M-1)]) ;
+
+	p = Gamma*p+(1-Gamma)*abs(U).^2 ;
+	p_inv = 1./p ;
+
+	PHI = ifft(p .* conj(U) .* E) ;
+	phi = real(PHI(1 : M )) ;
+	W = W + Mu / (2*M) * fft([phi; zeros(M,1)]) ;
+
+end ;
+
+% Plot results
+
+figure ;
+plot(20*log10(abs(e))) ;
+title('Learning Curve') ;
+xlabel('Iteration Number') ;
+ylabel('Output Estimation Error in dB') ;
+