METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING IN WIRELESS RELAY SYSTEMS BY USING SUPERPOSITION CODING

A method and an apparatus for transmitting or receiving data in a wireless relay system are provided to offer a multi-hop link through a relay station as well as a good direct link between a base station and a terminal, thereby improving the quality of communication and increasing the throughput of data. A base station superposition-codes a first message, X1, of N symbols including information bits for MS1 and a second message, X2, of N symbols including information bits for MS2, and then transmits the superposition-coded data(402). A relay station obtains the two messages by decoding the superposition-coded data, and then transmits D2 information bits extracted from the second message on M transmission symbols(404). The data transmitted from the relay station are transmitted to both the MS1 and the MS2. The MS1 receives the superposition-coded data from the base station and the data from the relay station. The MS1 obtains the first message by deleting a part related to the second message from the superposition-coded data, referring to the D2 information bits obtained by decoding the data received from the relay station, and then decodes the first message to achieve the D1 information bits(406).