| With the improvement of 5G mobile telecommunication technology,the number of mobile devices and the scale of wireless network increase rapidly.Simutanious wireless information and power transfer(SWIPT)enables receivers to decode information and scavenge energy from the same radio frequency signal,and provides a promising approach for energy-constrained problem and resource shortage in wireless networks and mobile devices.MIMO technology equips multiple antennas on both sides of each link,which can boost the channl capacity and the spectrum effectiveness,and thus improves the system performance.Application of SWIPT to multirelay system is investigated in this paper.A dual-hop relay system composed of one source node,multiple relays and multiple energy harvesting users is considered where the relays operate in full-duplex mode and the system takes co-channel interference into account.First,this paper proposed 2-step relay-user selection scheme:source-relay link and relay-destination link,in this way,the proper link is selected to transmit information.I proposed this optimization formulation based on minimizing the mean-squared-error(MSE)of the system.Due to the non-convexity of the problem,I proposed an iterative algorithm based on successive convex approximation and a closed-form suboptimal algorithm using Largangian dual function and Karush-Kuhn-Tucker(KKT)condition is derived to reduce the computational complexity.Theoretical proof and solution analysis is presented for both algorithms.Finally,Matlab simulation is used to verify the algorithms proposed.Results for MSE versus iterations and MSE versus SNR demonstrate the convergence and good performance of the proposed schemes.As illustrated in the results,the proposed algorithms converge rapidly within 30 iterations and the MSE performance of the SCA-based algorithm is better than that of the low-complexity suboptimal algorithm.Meanwhile,the result of MSE gets better when the number of antennas is increased. |
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