该文针对蜂窝终端直通(Device-to-Device,D2D)混合网络的两类终端提出一种新的无线资源调度策略,以提高混合网络整体性能实现无线资源的高效利用。该文无线资源调度问题分为频谱资源块和终端功率分配两个部分,首先,对该问题以混合网络和速率最大为优化目标进行理论建模,其约束条件为最大功率限制以及速率需求比值。速率需求比值可以用来区分蜂窝和直通(D2D)两类终端各自的速率需求,从而满足不同的服务质量(Quality of Service,QoS)。接着,通过拉格朗日乘数求解法,得到了上述最优化问题的最优解,即蜂窝和直通(D2D)终端分配的最优资源块序号以及功率值。从最优解可以看出,资源块的选取和功率分配两者互为条件选择的关系。根据这一结论,该文给出相应的调度策略,其中功率分配部分采用注水算法来实现。最后,通过系统级仿真,可以看出提出的新调度策略在混合网络的总吞吐和终端用户的公平性上都可实现较大提升。
端到端D2D(Device-to-Device)用户通过盲检测LTE系统中小区用户的物理层下行控制信道PDCCH(Physical Downlink Control Channel)获得小区中用户的资源分配信息,复用频谱资源,可以实现不经过基站的直联通信,提高无线资源利用率。提出一种基于"路径度量优势"进行PDCCH盲检测的实现方式,描述了它的计算方法,并对其性能进行了仿真分析。
With the increasing energy consumption, energy efficiency (EE) has been considered as an important metric for wireless communication networks as spectrum efficiency (SE). In this paper, EE optimization problem for downlink multi-user multiple-input multiple-output (MU-MIMO) system with massive antennas is investigated. According to the convex optimization theory, there exists a unique globally optimal power allocation achieving the optimal EE, and the closed-form of the optimal EE only related to channel state information is derived analytically. Then both the approximate and accurate power allocation algorithms with different complexity are proposed to achieve the optimal EE. Simulation results show that the optimal EE obtained by the approximate algorithm coincides to that achieved by the accurate algorithm within the controllable error limitation, and these proposed algorithms perform better than the existing equal power allocation algorithm. The optimal EE and corresponding SE increase with the number of antennas at base station, which is promising for the next generation wireless communication networks.
