Research On Non-orthogonal Multiple Access And Related Key Technologies

In recent years,with the rapid development of Internet of things and mobile Internet,higher transmission rate,lower time delay and higher connection density pose new challenges to the research of the fifth generation(5G)mobile communication.As one of the crucial candidate technologies for 5G mobile communication,non-orthogonal multiple access(NOMA)has attracted extensive attention of academia and industry due to its high spectrum efficiency.In this dissertation,research has been conducted on the combination of NOMA technology with SWIPT network and relay cooperative network.The performance and characteristics of future mobile communication are studied from terms of system sum rate,energy efficiency and user service quality.The main contributions of this thesis are summarized as follows.1.A novel uplink scheme based on NOMA and SWIPTAs the NOMA concept is applied to SWIPT system,a novel uplink scheme based on NOMA and SWIPT is proposed.The trade-off between the sum rate and the energy harvested by signal is modeled and analyzed according to the continuous interference cancellation technique and the dynamic power allocation strategy.We consider the average power constraint and peak power constraint of the user and the minimum energy constraint of the access point,mathematical modeling for the optimization problem in both cases is carried out to maximize the system sum rate.The optimal power allocation algorithm is obtained by mathematical analysis.Simulation results show that,compared with OMA scheme,the proposed uplink NOMA-SWIPT scheme achieve higher system sum rate with the same energy constraint.2.A new relay cooperative communication network based on NOMACooperative communication based on relay is a common scheme to improve communication network coverage.Minimizing the energy consumption of the relay communication system as well as satisfying the user rate requirement is an urgent problem which remains to be solved in the design and operation of the actual system.Therefore,a new relay cooperative network scheme based on NOMA is proposed,and the optimal power distribution expression is derived concerning the scheme.The simulation results verify the accuracy of our theoretical results and indicate that our NOMA collaboration solution can meet the user requirements of service quality with less energy consumption when comparing with the traditional OMA solution.