Patent ID: 6795392
Filing Date: 2004-09-21
Classification: H04L

Abstract:
A receiver comprising:one or more FFT elements responsive to respective receiving antennas, each developing a signal y[i,n,k], over channel i, where i designates an FFT element, n designates time, and k designates tone; a corresponding set of one or more filters â„‘, each filter i responsive to a corresponding output signal of an FFT element i of said one or more FFT elements for developing a signal y[i,n,k]&Hcirc;*[i,n,k]; a combiner responsive output signals of said one or more filters; a threshold decision element responsive to output signal of said combiner; and a channels estimator, responsive to output signal of said threshold decision element and to signals y[i,n,k] of all of said one or more FFT elements, for developing said signals &Hcirc;*[i,n,k], said channel estimator including a multiplication element for developing signals H~&af;[n,k]=[H~&af;[n,1]&vellip;H~&af;[n,K]]=[y&af;[n,1]&CenterDot;a_*&af;[n,1]&vellip;y&af;[n,K]&CenterDot;a_*&af;[n,K]]â€ƒand a matrix multiplication element for developing signals [H^&af;[n,1]H^&af;[n,2]&vellip;H^&af;[n,K]]=[&Sum;t=1K&it;â€ƒ&it;(u11&it;u11*+u12&it;u12*)&CenterDot;&Sum;m=-âˆž0&it;â€ƒ&it;Î¦1&af;(m)&it;H~&af;[k-m,l]&Sum;t=1K&it;â€ƒ&it;(u21&it;u11*+u22&it;u12*)&CenterDot;&Sum;m=-âˆž0&it;â€ƒ&it;Î¦2&af;(m)&it;H~&af;[k-m,l]&vellip;&Sum;t=1K&it;â€ƒ&it;(uK&it;1_&it;u11*+uK2&it;u12*)&CenterDot;&Sum;m=-âˆž0&it;â€ƒ&it;Î¦K&af;(m)&it;H~&af;[k-m,l]]â€ƒwhere umn are element of a matrix U is related to a Discrete Fourier Transform of a delay function, Î¦,(k)=1-1M1&af;(-k)&it;Î³1&af;[0],â€ƒM1(k)is a stable one-sided Fourier transform &Sum;n=0âˆž&it;â€ƒ&it;Î³i&af;[n]&it;&ee;-j&it;â€ƒ&it;mk,â€ƒand &ggr;i[n] is a coefficient in the frequency response of channel i.