多小区全双工分布式天线系统的能效资源分配

Energy Efficiency Resource Allocation for Multicell Full-Duplex Distributed Antenna Systems

针对多小区全双工分布式天线系统(DAS),提出了高能效的资源优化分配策略。所提策略在保证用户服务质量(QoS)需求的前提下,通过联合优化上下行波束赋形因子、用户发射功率和远端天线单元(RAU)选择来最大化系统能效。首先,把优化问题重新规划为一个秩约束的半正定规划问题,通过分式规划将目标函数由分式形式转化为减法形式,引入惩罚函数来处理整数变量,采用半正定松弛,提出了一种需要解决内部优化问题的迭代资源分配算法;然后,利用层次分解和连续凸逼近,将内部非凸问题转化为一系列凸优化问题循环迭代求解。仿真结果表明,文中提出的算法可以很快收敛,并且和其他基准算法相比可以极大地提升能效。

In view of the multicell full-duplex distributed antenna systems(DAS),this paper proposed an efficiency energy resource allocation strategy.Under the premise of guaranteeing the users’quality-of-service(QoS),this strategy jointly optimized the uplink and downlink beam-forming factors,user transmit power,and remote antenna unit(RAU)selection to maximize system energy efficiency.Firstly,the optimization problem was reformulated as a rank-constrained positive semi-definite programming problem,and the target function was converted from fractional order form to subtraction form through fractional programming.A penalty function was introduced to deal with integer variables and positive semi-definite relaxation was adopted,and an iterative resource allocation algorithm was proposed,which needs to solve internal problems in each iteration.Then,through hierarchical decomposition and successive convex approximation,the internal non-convex problem was transformed into a series of iterative convex optimization problems and solved.Simulation results show that the proposed algorithm can converge quickly and significantly improve the energy efficiency compared with other benchmark algorithms.