US 6,389,002 B1 · Broadband CDMA overlay system and method

Abstract

A spread-spectrum CDMA communications system for communicating data between a plurality of users to a plurality of spread-spectrum units. The spread-spectrum communications system is located within a same geographical region as occupied by an existing FDMA, proposed TDMA or any other mobile-cellular system. The spread-spectrum CDMA communications system includes a plurality of spread-spectrum-base stations and a plurality of spread-spectrum units. A spread-spectrum-base station has a comb filter for notch filtering predetermined channels of the mobile-cellular system, a device for converting the format of the data into a form for communicating over radio waves, a spread-spectrum modulator for spread-spectrum processing the data, and a transmitter for transmitting the spread-spectrum-processed converted data from the spread-spectrum-base station to a spread-spectrum unit. The spread-spectrum-base station also has an antenna, and spread-spectrum detectors for recovering data communicated from the spread-spectrum units. A spread-spectrum unit has an antenna, and a detector, including a spread-spectrum demodulator, coupled to the antenna for recovering data communicated from the spread-spectrum-base station, and the spread-spectrum unit has a spread-spectrum modulator, a transmitter, and a device for converting the format of the data for communicating over radio waves.

Claims20

Dependent claims

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.

3 more elements

A spread-spectrum code division multiple access (CDMA) communication system for non-interferingly overlaying spread-spectrum 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 system comprising:

one of said plurality of base stations comprising:
means for generating a spread-spectrum data signal having a pseudo random chip code sequence for a selected spread-spectrum unit within said one base station's operating area for transmission over the wide CDMA bandwidth;
means for determining the frequency bandwidths assigned to said sector 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;
means for notch filtering said spread-spectrum data signal at the determined frequency bandwidths;
and
means for transmitting said notch filtered spread-spectrum data signal to said selected unit over the wide bandwidth;
and
said selected unit comprising:
means for receiving said notch filtered spread-spectrum data signal.

6 more elements

Dependencies are inferred from the claim text.

Broadband CDMA overlay system and method

Life of this patent

Broadband CDMA overlay system and method

Life of this patent

Abstract

Claims20