| 摘要 |
A method and an apparatus for shortening handover delay time in a communication system are provided to shorten handover interruption time by shortening HARQ operation time which is generated from a packet transmitted right after handover to a target BS(Base Station) and to allocate the number of sub-channels and MCS levels. A target BS selects MSs(Mobile Stations) to transmit data at the present TTI(Transmission Time Interval). The target BS receives CQI information and service type information from the selected MSs. Using the CQI information, the serving BS determines an MCS level and the number of sub-channels to be allocated at the present TTI(445). Then the serving BS transmits packets to the MSs through the allocated sub-channels at the determined MCS level(450). An MS decodes the first packet, transmitted from the serving BS, using a HARQ technique based on chase combining(455). If decoding for the first packet failed, the MS transmits a NACK message to the serving BS(460). Receiving the NACK message, the target BS retransmits the first packet to the MS(465). The MS executes decoding a packet obtained through the soft combining of the first packet and the retransmitted packet(470). If the MS succeeds in decoding, the MS transmits an ACK message to the target BS(475). |
