Function to perform Adaptive filtering
This function performs echo cancellation using NLMS adaptive filter
function[y,M] = adapt_filt(xlms,B,h,delta,l,l1)
//x = the signal from the speaker directly
//B = the signal thorugh the echo path
//h = impulse response of adaptive filter
//l = length of signal 'x'
//l1 = length of adaptive filter order
for k = 1:150
for n = 1:l
xcap = xlms((n+l1-1):-1:(n+l1-1)-l1+1);
yout(n) = h*xcap;
e(n) = B(n)- yout(n);
xnorm = 0.001+(xcap*xcap');
h = h+((delta*e(n))*(xcap'));
end
eold = 0.0;
for i = 1:l
MSE = eold+(e(i)^2);
eold = MSE;
end
if MSE <= 0.0001 then
break;
end
end
y = zeros(1,length(e));
M = zeros(1,length(h));
y = e;
M = h;
endfunction