软件定义车联网中缓存辅助的NOMA功率分配方案研究

ue to the increasing demand for rich multimedia services, Internet of vehicles needs to provide massive equipment connections to meet the needs of high spectrum efficiency and low delay. Software Defined Network (SDN) , caching and Non-Orthogonal Multiple Access (NOMA) technologies are considered as potential solutions to effectively solve these key challenges. Therefore, this paper proposed a cache aided NOMA power allocation scheme for software defined vehicular network. Firstly, according to the characteristics of vehicles always moving at high speed in Internet of vehicles, the scheme proposed a new cluster head selection algorithm. The arriving road traffic will be predicted with the help of SDN to realize adaptive vehicle clustering. Secondly, the scheme introduced a cache aided NOMA strategy. Each vehicle uses NOMA principle to cache and request files in the file cache stage. Thirdly, for the two cluster head vehicle communication scenarios under the condition of double Nakagami-m fading, the scheme proposed an optimal power allocation strategy. The optimization problem is formulated as finding the optimal power curve of each vehicle, so as to maximize the probability of successfully decoding the target file on each vehicle. Finally, numerical simulation and theoretical analysis show that the performance of the proposed cache aided NOMA power allocation scheme is significantly better than the conventional NOMA and cache aided Orthogonal Multiple Access (OMA) .