Before transmitting an upward traffic packet of a long code, a mobile terminal sends a short packet including a short code to a reservation channel. A base station measures delay of each packet by an initial acquisition circuit to establish chip synchronization timing and a packet de-multiplexer to separate from each other packets overlapped in time with each other. When spreading the long-code packet transmitted via a traffic channel from the mobile terminal, information of the measured delay time is synchronously despread by setting a coefficient at an appropriate point of timing to a matched filter.