Abstract: Provided are an apparatus and a method for performing a handoff in a broadband cellular communication system with a frequency reuse factor of N by using both of two neighboring frequency allocations. The method includes determining, if a mobile station receives a signal from a second base station during communication with a second base station, whether frequency allocations of the two base stations are adjacent to each other, measuring and comparing signal strengths of the two base stations if the frequency allocations are adjacent to each other, sending a handoff request to the first base station if the signal strength of the first base station is less than or equal to the signal strength of the second base station, and simultaneously receiving signals of the two frequency allocations by simultaneously allocating portions of the frequency allocations to the mobile station according to the handoff request.

Abstract: A method is provided for transmitting a packet data unit (PDU) by a transmitter in a wireless mobile communication system. The method includes determining at least one desired transmission PDU, determining a modulation scheme corresponding to the number of PDUs, and transmitting a first indicator value indicating the number of PDUs and the modulation scheme, transmitting the PDUs, receiving a second indicator value indicating a reception state of the PDUs, from a receiver that receives the PDUs, determining a new PDU or a retransmission PDU according to the second indicator value, and determining a modulation scheme corresponding to the number of the determined PDUs, and transmitting a third indicator value indicating the number of PDUs and the modulation scheme, and the corresponding PDUs.

Abstract: Provided is an apparatus and method for simultaneously receiving data signals of two adjacent frequency allocation (FA) in a cellular environment. When there is another base station using an adjacent FA to an FA of the base station, a subcarrier mapper maps control information to subcarriers of predetermined sections such that a mobile station simultaneously receives data signals of the adjacent FAs. An inverse fast Fourier transform (IFFT) processor IFFT-processes data mapped to the subcarriers. Because two different BSs transmit the same data through independent paths, the mobile station can obtain a macro diversity gain. Also, it is possible to balance the loads of the two BSs.

Abstract: Disclosed is a method for determining handover of a mobile station by a mobile station in a mobile communication system. The method includes measuring a downlink reference signal intensity of a serving base station; determining to perform scanning for measurement of reference signal intensities of the serving base station and neighbor base stations, when the measured downlink reference signal intensity of the serving base station is less than a reference value, negotiating with the serving base station for a scanning period and the number of scanning repetitions, measuring the reference signal intensities of the serving base station and the neighbor base stations, and resetting the reference value when a reference signal intensity of the serving base station is greater than or equal to reference signal intensities of neighbor base stations.

Abstract: Provided is a method for determining handover of a mobile station by a serving base station in a mobile communication system. The method includes receiving traffic quality information from the mobile station; determining whether the traffic quality information satisfies a preset setting condition; if the traffic quality information satisfies the setting condition, sending a request for pilot signal strength measurement for the serving base station and adjacent base stations to the mobile station; receiving pilot signal strengths of the base stations, reported by the mobile station; determining whether there is a corresponding base station whose pilot signal strength exceeds the pilot signal strength of the serving base station; and determining handover of the mobile station to the corresponding base station.