Patent ID: 8605670

Claim:
A method, for selecting a relay station in cognitive radio system, the method comprising: obtaining channel status information; and selecting k* CGR -th candidate relay station as a relay station from a plurality of candidate relay stations using the following equation: k CGR * = arg ⁢ max k ⁢ min ⁢ {  h SR k  2  h SP  2 ,  h R k ⁢ D  2  h R k ⁢ P  2 } , wherein k is a natural number ranging from 1 to K, K is the number of the plurality of the candidate relay stations, h SR k is a channel gain from a non-licensed source station to a k-th candidate relay station, h R k D is a channel gain from the k-th candidate relay station to a non-licensed target station, h SP is a channel gain from the non-licensed source station to a licensed target station, and h R k P is a channel gain from the k-th candidate relay station to a licensed target station, and wherein the channel status information includes h SR k , h R k D , h SP , h R K P .