BASE STATION DEVICE AND PACKET TRANSMISSION METHOD

摘要

A despreading section 104 outputs a signal indicative of the number of paths through which despreading is performed to a likelihood calculating section 108. The fD detecting section 107 detects Doppler frequency (fD) that is a fading variation of the propagation path between each communication terminal apparatus and a base station apparatus from the despread signal. A likelihood calculating section 108 calculates likelihood of a report value transmitted from each communication terminal apparatus based on the number of paths which despreading is performed and the Doppler frequency. A transmission destination deciding section 151 decides a communication terminal apparatus that transmits a high-speed downlink packet based on a determination value obtained by multiplying the report value by the likelihood. A modulation scheme deciding section 152 decides an encoding rate of the high-speed downlink packet and a modulation scheme thereof based on the determination value. Accordingly, in high-speed downlink packet access, the error included in the report value is considered to perform transmission, making it possible to attain a reduction in the number of retransmission, improvement in transmission efficiency, and an increase in system capacity.