Research On Resource Allocation Algorithm Of NOMA Systems Based On Energy Efficiency

In the current mobile communication network,in response to the explosive development of the Internet and the Internet of Things in the future,it faces a series of challenges: high energy consumption,scarce spectrum resources,difficulty in efficiently coping with the future growth of thousands of business traffic and massive equipment access,and diversified extreme performance requirements.Faced with the severe situation in current mobile communication networks,the proposal of non-orthogonal multiple access(NOMA)technology meets the needs of future communication development to a certain extent,enabling large-scale user access,higher spectral efficiency and energy efficiency.Therefore,this thesis will explore the resource allocation of the NOMA system in terms of energy efficiency,maximize system energy efficiency,and achieve green energy-saving communication.Firstly,the resource allocation of energy-efficient single-carrier non-orthogonal multiple access(NOMA)system is studied,which considering the constraints of transmit power limitation and user quality of service,and the energy efficiency maximization model of the full-duplex NOMA system is established under ideal channel conditions.Since the optimization model has a fractional form,the original problem is firstly transformed by using Fractional Programming Theory.An internal and external two-layer iterative algorithm based on Dinkelbach algorithm and Lagrange multiplier method is proposed.Firstly,the inner layer problem is solved to obtain the optimal power allocation strategy,and then the outer layer is used to calculate the system energy efficiency.The simulation proves that the scheme is superior to the traditional Orthogonal Multiple Access(OMA)scheme.Secondly,the resource allocation of energy-efficient Multi-Carrier Non-Orthogonal Multiple Access(MC-NOMA)system is studied,and the energy efficiency optimization model of NOMA system is established.Due to the non-convexity of the objective function and the interference between users on the same subcarrier,the solution of the objective function depends on the user's subcarrier selection and power allocation strategy,so the problem is decoupled into two sub-problems: user pairing and power allocation.Firstly,a user and subcarrier matching algorithm is proposed to obtain the user matching scheme,and then use the Fractional Programming Theory to convert the original problem into an equivalent transformation and obtain the power allocation scheme through the interior point method.Finally,an optimal iterative algorithm for joint subcarrier and power allocation is proposed.The superiority of the algorithm is verified by simulation results.