Analysis of relay handoff algorithms in cooperative diversity systems using absolute and relative measurements of energy gain

Multi-user cooperative diversity is a recently proposed technique, which can improve the performance of wireless communication systems operating in fading environments. Choosing a good partner is important in cooperation and some partner selection methods have been proposed. However, there is no research has mentioned how often partners should be reassigned. In this paper, we propose a handoff scheme between relays. In the proposed scheme, handoff is performed when the energy gain of the working relay drops below a threshold and the energy gain of the best relay exceed the energy gain of the working relay by a certain hysteresis level. Simulation results are given to show the performance of the newly proposed scheme.