Abstract: Disclosed is an apparatus for determining transmit power of an uplink frame transmitted from a subscriber station to a base station and transmitting data in a mobile communication system in which a downlink frame, transmitted from the base station to the subscriber station, and the uplink frame are time division-duplexed (TDD). The apparatus includes a receive power measurement unit for measuring receive power of signals received from the base station; a transmit power controller for determining the transmit power of the uplink frame from the receive power measured by the receive power measurement unit and information related to receptions of an uplink frame, which is received from the base station; and a transmission radio frequency processor for performing radio processing so that the uplink frame is transmitted according to the transmit power determined by the transmit power controller.

Abstract: Disclosed is an apparatus and method for allocating downlink/uplink subchannels for a soft handover in a broadband wireless access communication system, wherein the method includes the steps of configuring FUSC subchannels based on a predetermined FUSC subchannel configuration scheme by using an equal seed value in all cells; allocating a predetermined number of FUSC subchannels of the configured FUSC subchannels as soft handover subchannels; and allocating remaining subchannels, except for the FUSC subchannels allocated as the first subchannels, as non-soft handover subchannels based on the FUSC subchannel configuration scheme by using a specific seed value.

Abstract: Disclosed is a method for transmitting a pilot symbol from base stations (BSs) to a subscriber station (SS) in a communication system which includes the base stations located adjacent to each other, the method includes the steps of transmitting BS-identifying sub-carriers which represent sequences for identifying the base stations in a frequency domain of the pilot symbol; and transmitting PAPR (Peak to Average Power Ratio) sub-carriers which represent sequences for reducing a PAPR of the pilot symbol together with the transmission of the BS-identifying sub-carriers in the frequency domain.

Abstract: A method for supporting a handover in a broadband wireless access communication system including an MSS, a serving BS providing service to the MSS, and a plurality of neighbor base stations, in which each of the BSs includes cells using different sub-channel bands. The method includes: measuring, by the BSS, intensities of signals received from the BSs, transmitting to the serving BS a request for a handover based on the measured signal intensities, establishing a connection with a target BS, to which a handover of the MSS is requested, from among the neighbor BSs before terminating a connection with the serving BS, and performing a soft handover by establishing a simultaneous connection with the two BSs in a handover area. The serving BS and the target BS allocate the same sub-channel including the same sub-carriers to the MSS when the mobile subscriber station performs the soft handover.

Abstract: Disclosed is a method for supporting a handover in a broadband wireless access communication system which includes a mobile subscriber station, a serving base station currently providing service to the mobile subscriber station, and a plurality of adjacent base stations different from the serving base station, in which each of the base stations includes cells using subchannel bands different from each other, the method including establishing a set of base stations which currently provide wireless channels for data transmission/reception to the mobile subscriber station; classifying, by each base station, entire subchannels into a plurality of sets of subchannels; and allocating each of the sets of subchannels obtained by the classification to a PUSC (Partial Usage of Subchannels) subchannel area of each sector, wherein, every base stations included in an active set select an equal number of PUSC subchannels from among a PUSC subchannel area allocated to each of the base stations and allocate the selected PUSC

Abstract: A method for setting a guard interval for distinguishing a transition from a downlink period to an uplink period in a mobile communication system employing a time division duplexing (TDD) scheme, the mobile communication system including a plurality of base stations. The method includes the steps of, simultaneously transmitting by each of the base stations downlink signals from transmission antennas at a first time point based on a processing delay time for a signal to be transmitted; simultaneously receiving by each of the base stations an uplink signal at reception antennas at a second time point; and setting a time interval from the first time point to the second time point as a guard interval for distinguishing a transition from an uplink period to a downlink period.

Abstract: Disclosed is an apparatus for determining transmit power of an uplink frame transmitted from a subscriber station to a base station and transmitting data in a mobile communication system in which a downlink frame, transmitted from the base station to the subscriber station, and the uplink frame are time division-duplexed (TDD). The apparatus includes a receive power measurement unit for measuring receive power of signals received from the base station; a transmit power controller for determining the transmit power of the uplink frame from the receive power measured by the receive power measurement unit and information related to receptions of an uplink frame, which is received from the base station; and a transmission radio frequency processor for performing radio processing so that the uplink frame is transmitted according to the transmit power determined by the transmit power controller.