Joint Optimization Algorithm Design For Relay And Direct-link System With Swipt

MIMO networks can greatly improve the capacity of the channel and make full use of space resources by setting multiple antennas at the source node and destination node.Therefore,MIMO become the core technology of mobile communication at present.The idea of simultaneously information and power transmit(SWIPT)technology is that transmitting information and energy simultaneously by the same wireless signal,it proposed a feasible approach to alleviate energy scarcity in energy-constrained wireless networks and mobile devices.It is accord with the idea of green communication,and having importance of actual meaning significance.Relay MIMO systems with SWIPT are investigated in this paper.In order to obtain additional diversity and further improve transmission reliability,I take the direct source-destination link into account in one-way and two-way relay systems with power split.First,the one-way system with energy harvesting at destination is investigated.The optimal problem was established based on the minimum mean square error(MSE).An algorithm which is based on successive convex approximation(SCA)and a low complexity solution using singular value decomposition(SVD)as well as generalized singular value decomposition(GSVD)techniques is derived.In addition,two special cases that the system only with direct link and the system only with relay link transmission are analyzed to demonstrate the outstanding performance of the proposed system.Then,I study a two-way relay and direct-link system with power split at relay.According to practical communication,I proposed a three time-slot protocol to transfer information between source and destination nodes.In order to solve the non-convex constraint,we use successive convex approximation(SCA)method for convex approximation.Using Lagrange dual function and KKT conditions,the optimized dual vector was solved.Finally,the systems proposed in this paper are simulated by matlab platform.Numerical results for iterations and bit-error-rate are carried out to demonstrate the good performance of the proposed schemes.Comparing the simulation results for the same system and different optimization algorithms,we analyzed the advantages and disadvantages of different optimization algorithms based on MSE versus number of iterations and BER versus SNR.