Radio communication system and transmission and/or receiving apparatus for use in the system

摘要

A radio communication system includes a transmission apparatus and a reception apparatus, enabling to retransmit a frame which has caused a code error in the CDMA method, without lowering the transmission capacity. The transmission apparatus includes: an encoder for encoding an information to be transmitted and adding an error detection code; a storage; a transmission channel; a first multiplier provided in the transmission channel, for multiplying an output signal from the encoder by a first diffusion code so as to be a transmission signal destined to the reception apparatus; a second multiplier for multiplying a signal received from the reception apparatus, by a second diffusion code; a decoder for decoding the output signal from the second multiplier; and a transmission/reception block. The reception apparatus includes: a first multiplier for multiplying a reception signal from the transmission apparatus, by the first diffusion code; a decoder for decoding an output signal from the first multiplier and checking whether the reception signal contains a code error according to the error detection code; an encoder for encoding a retransmission request identifying a frame number which has caused a code error if any detected by the decoder; a second multiplier for multiplying an output signal from the encoder, by the second diffusion code, so as to be a transmission signal destined to the transmission apparatus; and a transmission/reception block.