Patent ID: 7606182

Claim:
A cooperative relay transmission method for use in a base station of a wireless communication system configured by a plurality of terminals and the base station for providing a network access service to the plurality of terminals in which one of the plurality of terminals is selected as a source terminal and at least one of the other terminals is used as a relay node for relaying communication between the base station and the source terminal, comprising: initializing parameters for relay communication; broadcasting a relay communication request message comprising the parameters; setting a possible relay terminal for performing the relay communication between the base station and the source terminal among the plural of terminals in response to the relay communication request message; receiving uplink signals from the source terminal and relay terminals; and combining and decoding the uplink signals received from the source terminal and relay terminals, wherein the parameters include a maximum number of relay terminals (N max ), a minimum number of relay terminals (N min ), and a required channel quality (Q) and an allowable relay distance (D) for setting a relay terminal, and wherein the step of setting the relay terminal comprises: measuring a channel quality (Q present ) linked to the base station in a terminal receiving the relay communication request message; determining whether a condition of Q<Q present is satisfied; activating a relay function if the condition Q>Q present is satisfied; identifying a present number of relay terminals (Q present ) through control channel monitoring in the base station; determining whether a condition of N max >N present is satisfied; incrementing the required channel quality (Q) if the condition of N max >N present is not satisfied; determining whether a condition of N min >N present is satisfied if the condition of N max >N present is satisfied; and decrementing the required channel quality (Q) if the condition of N min >N present is not satisfied.