超密度异构蜂窝网络能效优化

利用泊松点过程理论研究了超密度异构蜂窝网络中的基站部署问题，特别是小基站密度对网络能量效率的影响，提出了一种通过优化小基站密度来实现网络能效最大化的方法.首先，借助泊松点过程理论对超密度异构蜂窝网络进行建模，推导了各层基站的覆盖概率以及基于业务荷载的最低可达速率，得出整个网络的最低可达吞吐量；其次，根据网络能效的定义，结合基站能耗模型，推导了与基站密度相关的网络能效的闭合表达式；最后，就小基站密度对网络能效的影响进行分析，提出了一种基于牛顿搜索法的小基站密度优化算法，实现网络能效的最大化.仿真结果验证了理论分析的正确性，同时也表明通过优化小基站部署密度完全能够实现网络能效的最大化.

Energy Efficiency Optimization for Ultra Dense Heterogeneous Cellular Networks

Based on Poisson point process(PPP) theory in stochastic geometry,the base station(BS) deployment problem in ultra-dense heterogeneous cellular networks,especially the influence of the distribution density of small cells on network energy efficiency is studied,and a method to maximize network energy efficiency(EE) through optimizing the density of small cells is proposed. Firstly,the coverage probability of each tier BS and the BS load oriented minimum achievable rate are derived through the PPP theory. Secondly,according to the definition of network EE and base station energy consumption model,the closed expression of network EE related to BS density is derived. Finally,the influence of the distribution density of the small cells on the network EE is analyzed,and an optimization algorithm of the small cell density based on Newton search method is proposed to maximize the network EE. Simulations verify the correctness of the theoretical analysis;and show that the network EE can be maximized through optimizing the deployment density of small cells.