Research On Low Energy Consumption Transceiver Design Of Two Way AF MIMO Relay Systems

Relay technology can improve the coverage and the reliability of communication systems; Multiple input multiple output (MIMO) technology can provide the spatial degree of freedom, provide spatial multiplexing gain and diversity gain, and improve the rate and reliability of data transmission; therefore MIMO relay technology which combines relay and MIMO is widely concerned and studied by the academic community. Two way relay can provide a higher spectral efficiency than one way relay, and thus two way amplify and forword (AF) MIMO relay system has become a hot research. Currently optimizing system performance, such as maximizing the rate, minimizing the mean squared error (MSE). with power constraints is studied. However energy conservation has become the consensus of the world, and reducing the energy consumption of the communication process has become a major requirement of communication systems, to this end the paper focuses on the low energy consumption transceiver design of two way AF MIMO relay systems.In the multiple user pairs two way AF MIMO relay system, this paper jointly optimizes user precoding matrices, relay precoding matrix and user receive matrices to minimize total power consumption of relay and all users with user MSE constraints. The optimization problem is nonconvex, and is difficult to solve directly. We decompose the original problem into three subproblems:optimizing user receive matrices with fixed user precoding matrices and relay precoding matrix, and this sub-problem is easy to solve; optimizing relay precoding matrix with fixed user precoding matrices and user receive matrices, and this subproblem can be transformed into a quadratically constrained quadratic programming (QCQP) problem; optimizing user precoding matrices with fixed relay precoding matrix and user receive matrices, and this subproblem can also be transformed into a QCQP problem. After the three subproblems are solved, an iterative algorithm based on alternating optimization is proposed to solve the original problem. Simulation results show that the proposed algorithm is convergent and can save power consumption effectively.In the non-simultaneous cellular two way AF MIMO relay system, we jointly optimize base precoding matrix, relay precoding matrix and base receive matrix to minimize the total power consumption of the base station and the relay with the MSE constraints of the base station and the receive-only users. Due to the nonconvexity of the problem, the original problem is decomposed into three subproblems:optimizing base receive matrix with fixed base precoding matrix and relay precoding matrix, and it is easy to solve; optimizing relay precoding matrix with fixed base precoding matrix and base receive matrix, and it can be transformed into a semidefinite programming (SDP) problem; optimizing base precoding matrix with fixed relay precoding matrix and base receive matrix, and it can also be transformed into a SDP problem. After the three subproblems are solved, an iterative algorithm based on alternating optimization is proposed to solve the original problem. Simulation results demonstrate the convergence and the performance of the proposed algorithm.