Research On NOMA-SWIPT Cooperative Transmission Technology Based On Limited Feedback

Non-orthogonal multiple access(NOMA)can effectively improve spectrum efficiency and increase the number of user connections in the increasingly scarce spectrum resources and large-scale connected intelligent terminals.Wireless Information and Energy Simultaneous Transmission(SWIPT)technology can effectively improve the quality of communication services and solve the problem of wireless device power supply in specific scenarios.Since the feedback capacity of the actual channel is limited,the complete CSI of the channel feedback will bring a great burden,and the improvement of the transmission performance depends on the acquisition of the CSI by the transmitter.Therefore,the research is based on the NOMA system under the condition of limited feedback and its feedback method has become a research hotspot.In an actual wireless communication scenario,due to the openness and fading performance of the wireless channel,it is difficult for the system to obtain complete channel state information.In the transmission process,there are problems such as low energy efficiency and user information being eavesdropped.Comparing with the traditional feedback technology,this paper designs a dual codebook feedback scheme in the NOMA-SWIPT system to improve the energy required and the energy efficiency of the system.In this system,in order to ensure the physical layer security transmission of the downlink,a physical layer security transmission scheme suitable for anti-eavesdrop users is proposed to improve the security performance of the system.Firstly,for the NOMA-SWIPT system with non-ideal information channel,a dual codebook feedback scheme is designed.When the channel direction information is fed back,the required power of the receiver is feedback to the transmitter as channel quality information.In the case where the total number of feedback bits is limited,the number of feedback bits is reasonably allocated to obtain optimal performance and achieve optimal energy efficiency.When the scheme fixes the total number of feedback bits,the verification shows that the proposed dual codebook feedback improves the accuracy of the feedback and improves the energy efficiency of the system.Secondly,the physical layer security transmission problem of the NOMA-SWIPT system based on the double codebook feedback is studied.The NOMA-SWIPT cooperative transmission system is constructed.In the incomplete channel state information scenario,the dual codebook feedback scheme proposed in this paper is adopted,and the artificial noise-assisted safety beamforming scheme is added.The convex optimization theory is used to derive the safe transmission rate of the system to ensure the user energy.The optimal situation is allocated to maximize the secure transmission rate of the NOMA-SWIPT system.The verification and indication of the double-codebook feedback method with artificial noise added to the physical layer security transmission performance of the system,and verified the improvement of the safe transmission rate.