Outage probability and power allocation strategy in a two-way relay system

The performance of outage in a two-way relay system in Nakagami-m fading channels was studyed.First,a lower bound of outage probability was derived by Monte Carlo simulation and then the simulation result was compared with the lower bound in theory.Simulation results show that the simulated outage probability is very close to the value in theory.Furthermore,in considering a total power constraint,and according to the optimization criterion of minimizing the outage probability,an optimum power allocation method based on SNR balancing was proposed.This method makes it possible for two destination nodes to adaptively adjust the sending power based on the change of instantaneous channel conditions.Simulation results show that the proposed method notably improved the system outage performance,compared to the equal power allocation method.