Patent ID: 6421330
Filing Date: 2002-07-16
Classification: H04J

Abstract:
An apparatus for expanding a service area of a CDMA mobile communication system from a first zone resulting from a restriction of the service area occurring in terms of timing to second, third and fourth zones gradually expanding wider than the first zone by a distance not longer than a cell radius allowed by a base station modem application-specific integrated circuit (ASIC) equipped in the system, comprising:a clock generating unit for receiving 10 MHZ, time of day (TOD), and 1-pulse per second (PPS) signals from a global positioning system (GPS) receiver and generating a first even-second clock synchronized to the 1-PPS signal, the clock generating unit also generating second, third, and fourth even-second clocks delayed by respective maximum bidirectional propagation delay values associated with the second, third and fourth zones; a first signal processing unit for receiving the first even-second clock from the clock generating unit, the first signal processing unit serving to, in regard to forward links from an associated base station to mobile stations in the service area, modulate and transmit forward link channels covering all the first, second, third and fourth zones in sync with the first even-second clock while, in regard to reverse links from the mobile stations to the base station, detecting and demodulating only reverse link channels transmitted from mobile stations located in the first zone in sync with the first even-second clock; a second signal processing unit for receiving the second even-second clock from the clock generating unit, the second signal processing unit serving to detect and demodulate only reverse link channels transmitted to the base station from mobile stations located in the second zone in sync with the second even-second clock; a third signal processing unit for receiving the third even-second clock from the clock generating unit, the third signal processing unit serving to detect and demodulate only reverse link channels transmitted to the base station from mobile stations located in the third zone in sync with the third even-second clock; and a fourth signal processing unit for receiving the fourth even-second clock from the clock generating unit, the fourth signal processing unit serving to detect and demodulate only reverse link channels transmitted to the base station from mobile stations located in the fourth zone in sync with the fourth even-second clock.