Patent ID: 6748011
Filing Date: 2004-06-08
Classification: H04L

Abstract:
A filter for a wireless communications system employing a multi-carrier signal comprising:first means for extracting carrier signal components from the multi-carrier signal; and second means for filtering the carrier signal components to generate a demodulated and filtered multi-bandwidth signal, wherein the second means includes an Infinite Impulse Response (IIR) filter for matching a pulse shape of the multi-carrier signal, and wherein the second means further includes means for compensating for pre-equalization effects on the multi-carrier signal to minimize phase non-linearity, and wherein the IIR filter is a 5th order elliptic IIR filter employed as a 1Ã— lowpass filter for lowpass filtering the carrier signal components, where the carrier signal components define three data streams separated in frequency, and wherein the IIR filter has a cascade direct form II structure and wherein the IIR filter is characterized by the following transfer function: H&it;(z)=Î±00&it;(Î²00+Î²01&it;z-1+Î²02&it;z-2)(1+Î±01&it;z-1+Î±02&it;z-2)&CenterDot;(Î²10+Î²11&it;z-1)(1+Î±11&it;z-1)&CenterDot;(Î²20+Î²21&it;z-1+Î²22&it;z-2)(1+Î±21&it;z-1+Î±22&it;z-2)where &agr;00, &agr;01, &agr;02, &agr;11, &agr;21, &agr;22, &bgr;00, &bgr;01, &bgr;02, &bgr;10, &bgr;11, &bgr;20, &bgr;21, and &bgr;22 are predetermined constants, and z is a complex variable.