Design Of Resource Scheduling Strategy Based On SWIPT In Heterogeneous Cloud Radio Access Network

Heterogeneous Cloud Radio Access Network(H-CRAN)takes full advantage of the dual advantages of Cloud Radio Access Network(CRAN)and Heterogeneous Network(Het Net),and it is regarded as next generation network architecture.Simultaneous Wireless Information and Power Transfer(SWIPT)can harvest energy via radio frequency signal(RF)while transmitting information to extend the life cycle of nodes and improve the energy efficiency of the system.In the context of mobile Internet and the Internet of Things(Io T),it is imperative to reduce communication energy consumption,seek energy-efficient wireless communication technologies and investigate reasonable and effective resource scheduling schemes.In this dissertation,joint subcarrier and power optimization strategy based on spectral efficiency maximization in H-CRAN is investigated.In addition,the joint optimization strategy of energy allocation and time switching(TS)coefficient based on SWIPT in H-CRAN is studied.With the consideration of energy harvesting constraints,the throughput maximization scheduling strategy based on energy harvesting constraints is discussed.The main research aspects of this dissertation are shown as below.1)The joint uplink and downlink resource allocation strategy based on cooperative multipoint(COMP)joint transmission in H-CRAN is investigated.Firstly,the mathematical optimization problem is established based on spectral efficiency maximization.Then,the tradeoff between spectral efficiency and energy efficiency is presented in H-CRAN.Through the joint optimization of subcarrier scheduling and allocation,RRH transmission power and HPN transmission power,the maximum system spectral efficiency can be achieved with the constraint of the maximum transmission power.In order to solve the original nonlinear integer optimization problem,the problem can be divided into two sub-problems.Power allocation of downlink and uplink are solved via iterative-based multi-base station joint allocation and KKT.Simulation results show that the proposed scheme outperforms the classical polling algorithm and equal power allocation algorithm.2)The joint optimization strategy of energy allocation and time switching(TS)coefficient based on SWIPT in H-CRAN is studied.Users share sub-channels through Non-orthogonal Multiple Access(NOMA)technology,and perform information decoding and energy harvesting respectively through time switching(TS).This strategy jointly optimizes the sub-channel,TS coefficient and the power of RRH and HPN.The proposed strategy takes H-CRAN energy efficiency as optimization objective to establish a mathematical optimization problem.A two-way matching sub-channel allocation algorithm is proposed.Then,the original problem is deformed via Dinkelbach method.Power and TS coefficient can be optimized through the inner and outer loop.Simulation results show that SWIPT technology greatly enhances system energy efficiency.In addition,as the minimum harvested energy increases,system energy efficiency is gradually decreased.The minimum transmission rate has no effect on system energy efficiency.3)The throughput maximization scheduling strategy based on energy harvesting constraints is discussed in H-CRAN.Firstly,the system model is established.The user uses power splitting(PS)to decode information and energy harvesting respectively in downlink,and the harvested energy can be utilized for uplink information transmission.Under the constraint of energy harvesting,a maximum system weighted throughput optimization problem is established.Considering the joint optimization of H-CRAN subcarriers,PS coefficient and power in uplink and downlink channel,the subcarrier,power splitting and power can be jointly optimized via greedy algorithm and Lagrange dual method to maximize system throughput under the constraints of the guaranteed minimum harvested energy.The dissertation conducts a preliminary research on the optimization strategies of multi-resource scheduling in H-CRAN combined with COMP and SWIPT technologies,and the research achievements provide significant value for the further related works.