Patent ID: 6389002
Filing Date: 2002-05-14
Classification: G01S,H04B,H04J,H04W

Abstract:
A method of non-interferingly overlaying spread-spectrum code division multiple access (CDMA) signals within a wide bandwidth over an existing cellular communication system, the existing system having a plurality of base stations, each said base station having an operating area divided into a plurality of sectors, each said base station's sector assigned predetermined frequency bandwidths within the wide CDMA bandwidth for use in communicating data between that sector's base station and non-CDMA cellular users within that sector, the method comprising:generating a spread-spectrum data signal having a pseudo random chip code sequence for a selected spread-spectrum unit within one of said existing base station's operating area for transmission over the wide CDMA bandwidth; determining the frequency bandwidths assigned to said sector of said one base station where said selected unit is located and the frequency bandwidths assigned to said sectors of others of said existing base stations contiguous with said selected unit's sector; notch filtering said spread-spectrum data signal at the determined frequency bandwidths; transmitting said notch filtered spread-spectrum data signal to said selected unit over the wide bandwidth; and at said selected unit, receiving said notch filtered spread-spectrum data signal.