CAJ | 학술논문

该文分析了蜂窝与终端直通(Device-to-Device, D2D)混合网络中多频带资源的场景下D2D用户最佳密度和功率分配问题。在混合网络中包含一个或者多个蜂窝网络，D2D 用户复用蜂窝系统上行频谱资源。通过采用随机几何理论，上述问题可以建模成一个以最大化 D2D 网络容量为目标并以蜂窝用户和 D2D 用户的中断概率为约束条件的优化问题。由于上述优化问题非凸，因此分成两步解决原问题：首先证明当D2D用户密度确定的时候原问题对于功率分配是凸问题，并通过拉格朗日对偶方法得到了最优功率分配方案；随后证明中断约束条件将 D2D用户密度的定义域分成有限个子区间，在每个子区间上可以通过求导的方式得到D2D传输容量局部最优解，基于上述两个结论，文中设计了一种子区间最优值搜索算法。通过仿真验证了算法的有效性，并且反映出D2D传输容量主要由中断约束条件和来自蜂窝网络的干扰决定。
해문분석료봉와여종단직통(Device-to-Device, D2D)혼합망락중다빈대자원적장경하D2D용호최가밀도화공솔분배문제。재혼합망락중포함일개혹자다개봉와망락，D2D 용호복용봉와계통상행빈보자원。통과채용수궤궤하이론，상술문제가이건모성일개이최대화 D2D 망락용량위목표병이봉와용호화 D2D 용호적중단개솔위약속조건적우화문제。유우상술우화문제비철，인차분성량보해결원문제：수선증명당D2D용호밀도학정적시후원문제대우공솔분배시철문제，병통과랍격랑일대우방법득도료최우공솔분배방안；수후증명중단약속조건장 D2D용호밀도적정의역분성유한개자구간，재매개자구간상가이통과구도적방식득도D2D전수용량국부최우해，기우상술량개결론，문중설계료일충자구간최우치수색산법。통과방진험증료산법적유효성，병차반영출D2D전수용량주요유중단약속조건화래자봉와망락적간우결정。
This paper analyzes the optimal density and power allocation for the D2D (Device-to-Device) communication in heterogeneous networks on multi-bands with target of maximizing the D2D transmission capacity. The heterogeneous networks contain one or several cellular systems, and the D2D communication shares uplink resources with them. By utilizing stochastic geometry, it is formed as a sum capacity optimization problem for the D2D network with constraints that guarantee outage probabilities of both cellular and the D2D transmissions. Since the original problem is non-convex, the proof work is divided into two steps:first, it is proved that the power allocation problem is convex when the D2D density is fixed, which can be solved by Lagrangian method;and then that the feasible region for the D2D user density is divided into finite sub-intervals by the outage constraints and the local maximum D2D transmission capacity can be obtained by the derivative method. A sub-interval linear searching algorithm based on the above conclusions is proposed. The simulation results demonstrate the effectiveness of the proposed algorithm and show that the optimal parameters of the D2D transmission is mainly affected by the outage constraints and the interference from cellular systems.