I am going through Average Magnitude Difference Function (AMDF), while exploring on this I found a good PDF Enhancing Echo Cancellation via Estimation of delay By Youhong lu,Ronald Fowler,Wenshun Tian and Leland Thompson. In which the delay estimation is done. I am going through this paper to understand the mathematical steps used for estimation of delay. I have got struck with the normalized coss correlation function formule given in this formula. The normalised cross correlation function (n,k) at the time n can be defined as R(n,k) = Pxy(n,k) / squareroot[Px(n-k) Py(n)] where x(n) is frend signal and y(n) be recieved echo, where n is the time index. The denominator part I have understood. Px(n) and Py(n) is the power ofx(n) and y(n) I have doubt in this part of the formula. I am not understand how cross correlation is calculated. Pxy(n,k) is the cross correlation function between x(n) and y(n) at ime n. L - 1 Pxy(n,k) = 1/ L summation x*(n- l �k) y(n � l) l = 0 Can you please help me in this regard Sir. _____________________________________ Do you know a company who employs DSP engineers? Is it already listed at http://dsprelated.com/employers.php ?

# Need argent help regarding delay estimation

Started by ●May 30, 2007

Reply by ●May 30, 20072007-05-30

L - 1> Pxy(n,k) = 1/ L summation x*(n- l -k) y(n - l) > l = 0 > > Can you please help me in this regard Sir. > > _____________________________________ > Do you know a company who employs DSP engineers? > Is it already listed athttp://dsprelated.com/employers.php?Look up convolution. Think of it almost like a convolution (in which you don't have to flip one of the signals over the t=0 axis).