Abstract: The RF receiver for the CDMA mobile communication BTS system according to the present invention realizes the system with an analog down-converter to process multiple FA's and generate IF signals of 70 MHz having a bandwidth corresponding to the multiple FA's with a mixer, and a digital down-converter to digitally process the respective FA's through A/D conversion of the IF signals of 70 MHz, allowing simple multi-FA(3FA)-based expansion. Also, the system needs only one analog down-converter for simultaneously processing 3 FA's and one digital down-converter for digitally processing the IF signals from the analog down-converter by FA's to down-convert the IF signals to baseband signals, thereby reducing the size of the system and hence the hardware cost. The system can be implemented with higher stability by digitally processing the down-conversion of the analog IF signals of multiple FA's to the baseband signals.

Abstract: A base station for compensating a fixed route delay between a base station and a mobile station of a CDMA mobile communication system and an operation method thereof are disclosed.

Abstract: A method for searching an access channel and allocating a finger for a base station is disclosed.

Abstract: A handoff method of a mobile communications system, in case that a cell is defined by a sector, wherein a handoff request is made to a base station having a predetermined level of pilot signal strength by using a pilot signal strength of a base station which is in service, a predetermined threshold value and pilot signal strength of neighboring base stations, so that a handoff is to be performed or not is decided after detecting pilot signal strengths of a mobile station and a base station which has been already connected, controlling the handoff generation number while preventing unnecessary load.

Abstract: A handoff trial method by a mobile station that compares a pilot power strength of a base station providing communication service to the mobile station with a pilot power strength of a neighboring base station and attempts to handoff based on the comparing results. As a result of comparing, if the difference is larger than a pilot threshold to try handoff, the mobile station transmits a signal measurement message to the service base station for handoff to the neighboring base station. Also, if the mobile station communicated with a plurality of base stations tries to cut calls with the base stations, the mobile station measures pilot power strengths of the service base stations compares therebetween. As a result of the comparing, if the difference is smaller than a pilot threshold to cut call, the mobile station tries to cut call with the associated base station.

Abstract: An apparatus and method for expanding a service area of a code division multiple access (CDMA) system restricted in terms of timing. The service area of a CDMA mobile communication system, which is defined by a radius longer than a radius of a communication supported area, namely, a cell, restricted in terms of timing due to the hardware of a base station modem ASIC equipped in the system, is radially divided into a plurality of radial zones by a constant distance not longer than a maximum possible cell radius allowed by the base station modem ASIC. In accordance with the present invention, signal processing units are used which are configured in such a fashion that one of them covers the entire zone of the service area in regard to forward links from an associated base station to mobile stations in different zones of the service area while covering only the zone nearest to the base station in regard to reverse links from the mobile stations to the base station.

Abstract: A method for operating a base station to solve a speech disable state based on the inter-speech sphere movement of a mobile station in enlarging a speech radius limited in timing in a CDMA mobile communication system. In a base station where a speech radius wider than that limited by a modem ASIC is partitioned by a predetermined radius unit into a plurality of speech spheres for the enlargement of the limited speech radius and channel elements are assigned to the partitioned speech spheres for transmission/reception of channels, a handoff operation is performed from an arbitrary channel element in the base station to a channel element assigned to a different speech sphere when a mobile station moves beyond an initial speech sphere during conversation with the arbitrary channel element. At this time, a reverse traffic channel is demodulated and remains at a standby state.

Abstract: A method of searching reverse traffic channels in a code division multiple access (CDMA) mobile radio communication system for allowing for acquisition of reverse traffic channels without increase or decrease of size of a search window for traffic channels, the method comprising the steps of: storing an offset by a propagation delay after acquiring a reverse access channel; determining whether or not a pseudonoise (PN) random delay is employed for the reverse access channel and, when the PN random delay is used, calculating the PN random delay using a hash function with a factor of an electronic serial number (ESN) transmitted from a mobile station; computing the stored offset and the PN random delay and setting a new offset to a result of the computing; setting a center of a search window for searching the reverse traffic channel to the new offset and establishing the search window; and searching a reverse traffic channel preamble with the established search window.

Abstract: A base station transmitted forward power is controlled in such a manner that identifies a mode of an input base station transmitted forward power control command; and controls an attenuation value of an attenuator in a power adjustment part according to a result of the identification so as to gradually increase or decrease a base station transmitted power, thereby effecting the base station transmitted forward power control without deterioration of speech quality and interruption of calls.