Joint Source And Relay Design For Multiple Two-way Relays MIMO Networks With Energy Harvesting

With the development of social science and technology,there is increasingly demanding for the quality of mobile communications.The multi-input and multi-output(MIMO)technology configures multiple antennas at the transmitting end and the receiving end,which can improve the channel capacity of the system,thereby improving the performance of the system,has become the core technology of the new generation mobile communication.The RF signal developed in recent years can be used as both a medium for energy transmission and a medium for information transmission,thus creating an emerging technology-Simultaneous Wireless Information and Power Transfer(SWIPT).Simultaneous Wireless Information and Power Transfer aims to realize the parallel transmission of information and energy,in line with the concept of green development.In order to improve the system throughput,two-way relay technology emerges as the times require.The transmission mode of the technology enables the spectrum efficiency to be effectively improved,the communication coverage area can be expanded,and the number of information transmission time slots can be saved.Communication not only requires a large capacity,but also requires the accuracy.The traditional single-relay system will cause more certain error risk in communication,resulting in more transmission of information errors.Cooperative communication refers to the addition of relay nodes in addition to direct transmission to ensure the correctness of information transmission,to combat fading and to provide spatial diversity.As much as possible to ensure the accuracy of the information.In this paper,the above several technologies are combined.A two-way cooperative relay system which can charge the users is studied in this paper,which will bring us great practical significance.In order to be more realistic,a time switching and power splitting receiver are provided at the receiver.Firstly,this paper studies the two-way cooperative system in the half-duplex relay system,and establishes the optimization problem by maximizing the system rate as the objective function.It proposes a successive convex approximation(SCA)based iterative algorithm and a singular value decomposition technology(SVD)based low complexity diagonalization algorithm.Two optimization algorithms optimize the beamforming matrix and the time-switching factor.The optimization performance of the two algorithms is compared.Secondly,this paper also studies the two-way relay cooperative system with power splitting receivers.The expression of signals are different between these two receivers,so the difficulty of varies decoupling,parameter setting and solving process.,which will be challenging to us.Based on the criteria for maximizing the rate,the beamforming matrix of the source and the relay is optimized using SCA based iterative algorithm and diagonalization algorithm.Finally,the article uses the MATLAB simulation platform to simulate the above-mentioned half-duplex system,and the system rate is used as the performance evaluation index.The obtained simulation results can verify the theoretical derivation of this paper,and also get the optimization algorithm.Comparison of optimization performance and advantages and disadvantages of different system models.The SCA based iterative algorithm has a slower convergence due to its higher complexity,but the system has a better rate.The complexity of the low complexity diagonalization algorithm is reduced,but the system rate is slower.Under certain simulation conditions,the more the number of antennas,the better the system information rate performance.