Research On Non-Orthogonal Multiple Access System Based On Wireless Energy Information Simultaneous Interpreting In Time Division Duplex

The rapid growth of the mobile Internet and the exponential increase of connected devices have made many challenges to future wireless networks,such as higher data rates,spectrum efficiency and lower delays.Wireless Information Energy Simultaneous Transmission(SWIPT)and NonOrthogonal Multiple Access(NOMA)are considered to be two technologies for the wireless networks.Combining SWIPT technology with NOMA technology not only has the advantage of energy saving,but also can improve spectrum efficiency.Therefore,the optimal resource allocation of the NOMA system supporting SWIPT is a hot issue worthy of attention.The current research work can only realize the application of NOMA technology in certain SWIPT scenarios,and fail to use fully the performance of SWIPT-based network systems.Therefore,this paper studies the resource optimization problem of wireless information energy simultaneous transmission system based on non-orthogonal multiple access,and the resource optimization problem of wireless information energy simultaneous transmission system based on non-orthogonal multiple access in time division duplex mode.The important work and contributions of the paper are as below:(1)Aiming at the characteristic that both SWIPT and NOMA technologies have great advantages,this paper analyzes and establishes a system model of SWIPT and NOMA based on the working principle of SWIPT,converts the collected energy into throughput,and decodes the information.The weighted sum of the throughput of energy conversion is used to establish a new objective function,which is defined as the equivalent sum rate(R),which jointly optimizes the base station's transmit power allocation and the user's power allocation ratio coefficient.Through nonconvex to convex,a new objective function is proposed about a joint optimization scheme of signal power and power allocation,and is proved the convergence of the algorithm.Numerical simulation results prove that compared with the Orthogonal Frequency Division Multiple Access(OFDMA)benchmark scheme that supports SWIPT,the NOMA joint resource optimization scheme that supports SWIPT proposed in this paper has significantly improved the system throughput,which increases from about 19bit/s/Hz to about 24bit/s/Hz.(2)On the basis of the previously established SWIPT joint NOMA system model,considering the combined uplink and downlink transmission,time division duplexing is introduced,and the SWIPT-NOMA system model under dynamic signal power allocation and dynamic time allocation is analyzed and established.Due to the complexity of the three variables,successive convex approximation is made use of solving the problem about non-convex,and a joint optimization scheme of signal power and time and power distribution is proposed.The solution to complex optimization problems is realized,and the convergence of the algorithm is clearly proved.Simulation results have proved that,contrast with the OFDMA benchmark scheme that supports SWIPT,the NOMA joint resource optimization scheme that supports SWIPT proposed in this article has significantly improved the total uplink and downlink throughput of the system.Throughput increases from about 21 bit/s/Hz to about 23 bit/s/Hz.