Multi-objective Optimization Design For MIMO AF Relay Systems

In wireless communication systems,the power consumption and the mean square error(MSE)performance are two key parameters in wireless communication systems.However,the two important system metrics are conflicting such that minimizing in power consumption always leads to the degradation in MSE performance.In order to balance the two conflicting objectives,this paper studies the multi-objective optimization(MOOP)of the power consumption and MSE.The main work is as follows:Firstly,we consider a two-hop MIMO amplify-forward(AF)relay system.In view of the conflicted relation of power consumption and MSE,a multi-objective optimization(MOO)framework is adopted to achieve the trade-off between two objectives.The multi-objective optimization problem is non-convex and hard to tackle.For the purpose of handling this problem,a low complexity resource allocation algorithm is proposed by applying the weighted Tchebycheff approach,the optimal structure of the relay precoding matrix and the Schur complement.In the end,we obtain the Pareto optimal boundary between the power consumption and the MSE through changing value of the objective preference variable.Secondly,considering the variability of communication systems,multiuser MIMO(MU-MIMO)relay downlink communication systems are studied.The multi-objective optimization framework is used to study the worst case MSE and the total power consumption of the system,and the Pareto optimal boundary between the two objectives is given.Finally,for the case of the situation of a node can be a transmitter and a receiver,we study the two-way MIMO relay system,and the relay protocol using two-slot MABC protocol.In this paper,we proposed an alternating optimization algorithm for the optimization peoblem,and the optimal solution is found by iterative method.In the end,the performance of the algorithm is verified by simulation.