Patent ID: 6205131
Filing Date: 2001-03-20
Classification: H04B

Abstract:
A reverse traffic channel circuit for Code Division Multiple Access (CDMA) based mobile stations, comprising:a plurality of input terminal means for separately receiving a digital fundamental input signal A.sub.0 and a plurality of digital supplemental channel input signals A.sub.1 to A.sub.7 ;quadrature spreading means for quadrature spreading the fundamental channel input signal and each supplemental channel input signal to produce, respectively, a fundamental in-phase channel signal F.sub.i, and a fundamental quadrature channel signal F.sub.q, and separate supplemental in-phase channel signals S.sub.1i, S.sub.2i, . . . S.sub.7i, and supplemental quadrature channel signals S.sub.1q, S.sub.2q, . . . S.sub.7q ;filtering means for separately filtering and scaling the fundamental in-phase channel signal F.sub.i, the fundamental quadrature channel signal F.sub.q, the separate supplemental in-phase channel signals S.sub.1i, S.sub.2i, . . . S.sub.7i, and the separate supplemental quadrature channel signals S.sub.1q, S.sub.2q, . . . S.sub.7q ;first combining means for combining the filtered fundamental in-phase channel signal F.sub.i ', some of the separate filtered supplemental in-phase channel signals S.sub.1i ', S.sub.2i ', . . .S.sub.7i ', and some of the separate filtered supplemental quadrature channel signals S.sub.1q ', S.sub.2q ', S.sub.7q ' according to the following formula: ##EQU13##to produce an overall in-phase digital output signal;second combining means for combining the filtered fundamental quadrature channel signal F.sub.q ', some of the separate filtered supplemental in-phase channel signals S.sub.1i ', S.sub.2i ', . . . S.sub.7i ', and some of the separate filtered supplemental quadrature channel signals S.sub.1q ', S.sub.2q ', . . . S.sub.7q ' according to the following formula: ##EQU14##to produce an overall quadrature digital output signal;digital to analog means for converting each of the overall in-phase digital output signal and the overall quadrature digital output signal into a corresponding overall in-phase analog output signal and a corresponding overall analog quadrature output signal, respectively; andquadrature modulating means for quadrature modulating the overall in-phase analog output signal with a carrier termcos(2.pi..function..sub.c t) to produce a first quadrature modulated result signal, quadrature modulating the overall quadrature analog output signal with a carrier term sin(2.pi..function..sub.c t) to produce a second quadrature modulated result signal, where f.sub.c is the carrier frequency and t is time, and combining the first quadrature modulated result signal with the second quadrature modulated result signal to produce a radio frequency output signal S(t).