D2D缓存网络中基于随机几何的成功卸载概率分析

针对所有移动用户均具有缓存能力的终端直传(D2D)缓存网络,将移动用户的位置分布建模为均匀泊松点过程(HPPP),并在此基础上结合内容缓存和内容请求的随机性,对网络干扰进行了精确分析和特定场景下的近似分析。考虑到D2D缓存技术融合了用户终端缓存与D2D通信的双重特点,即内容卸载包括自卸载和D2D卸载两种卸载方式、内容传输需要满足接收端信干比(SIR)和D2D距离的双重约束,利用随机几何理论推导出D2D缓存网络的成功卸载概率(SOP)的闭式表达式。仿真结果表明,结合D2D缓存网络特点的SOP更具有一般性,在特定场景下可以退化成已有研究中的特例。例如,在用户密集分布以及D2D最大通信距离较大的情况下SOP会退化成不考虑D2D距离约束的成功传输概率(STP)。

Successful offloading probability analysis in device-to-device caching network based on stochastic geometry

In the Device-to-Device (D2D) caching network where mobile user terminals are all cache-enabled, the spatial distributions of all users were modeled as the Homogeneous Poisson Point Processes (HPPP). On this basis, combined with the randomness of content caching and requesting, the network interference was analyzed exactly and then approximately under specific scenarios. Considering that the D2D caching technique has the dual characteristics of both caching at terminals and D2D communications, which means that the content offloadeding includes self-offloading way and D2D-offloading way, and the content transmission has to meet the constraints of received Signal-to-Interference Ratio (SIR) and D2D maximal communication distance simultaneously, the closed-form expressions of Successful Offloading Probability (SOP) of the random D2D caching network was deducted. Simulation results show that the proposed SOP is a general metric and can be reduced to the special cases of existing research results. For example, when the users are distributed densely and the D2D maximal communication distance is relatively large, the SOP is reduced to the Successful Transmission Probability (STP) without considering the D2D distance constraint.