Partner selection strategy for users with high speed in cooperative diversity systems

Cooperative diversity has been adopted to form virtual antenna arrays in order to obtain spatial diversity gains. Various partner selection methods in cooperative diversity systems were proposed and analyzed. However, these methods are not effective for users with high speed, such as users in cars on high way. A novel partner selection strategy is presented in this paper by dividing users into three groups according to their moving speeds and directions if there are any high speed users in a certain cell. The partners for cooperation are selected from the same group with the source user. Simulation results show that the selection strategy can increase duration of cooperation, as well as decrease the partner handoff times and probability of unsuccessful partner selection.