The Full Dimension-MIMO (FD-MIMO) technology is capable of achieving huge improvements in network throughput with simultaneous connectivity of a large number of mobile wireless devices, unmanned aerial vehicles, and the Internet of Things (IoT). In the Long Term Evolution (LTE), with a large number of antennae at the base station and the ability to perform beamforming, the capacity of the physical downlink shared channel (PDSCH) has increased a lot. However, the current $3^{rd}$ Generation Partnership Project (3GPP) specifications of the LTE do not allow the base station to perform any beamforming techniques for the physical downlink control channel (PDCCH). Hence, PDCCH has neither the capacity nor the coverage of PDSCH. Therefore, PDCCH capacity still limits the performance of a network, as it dictates the number of users that a base station can schedule at a given time instant. In Release 11, 3GPP introduced enhanced PDCCH (EPDCCH) to increase the PDCCH capacity at the cost of sacrificing the PDSCH resources. The problem of enhancing the PDCCH capacity within the available control channel resources has not been addressed yet in the literature. Hence, in this paper, we propose a novel beamformed PDCCH (BF-PDCCH) design which is aligned to the 3GPP specifications and requires simple software changes at the base station. For the evaluation of the proposed BF-PDCCH, we model various link abstractions. We evaluate them through link-level simulations and then use all these abstractions in the system-level simulations. We show that the proposed BF-PDCCH achieves significant improvement in network throughput and outperforms the current state of the art algorithms, PDCCH, and EPDCCH schemes.

多维MIMO（FD-MIMO）技术能够通过同时连接大量移动无线设备，无人机和物联网（IoT）来实现网络吞吐量的巨大提高。在长期演进（LTE）中，基站具有大量天线，并且具有执行波束成形的能力，因此物理下行链路共享信道（PDSCH）的容量已大大增加。但是，目前$3^{\mathrm{[R}d}$LTE的世代合作伙伴计划（3GPP）规范不允许基站执行用于物理下行链路控制信道（PDCCH）的任何波束成形技术。因此，PDCCH既不具有PDSCH的容量也不具有PDSCH的覆盖范围。因此，PDCCH容量仍然限制了网络的性能，因为它决定了基站在给定时刻可以调度的用户数量。在版本11中，3GPP引入了增强型PDCCH（EPDCCH），以牺牲PDSCH资源为代价来增加PDCCH容量。在文献中尚未解决在可用控制信道资源内增强PDCCH容量的问题。因此，在本文中，我们提出了一种新颖的波束成形PDCCH（BF-PDCCH）设计，该设计符合3GPP规范，并且需要在基站上进行简单的软件更改。为了评估所提出的BF-PDCCH，我们对各种链路抽象进行了建模。我们通过链接级仿真对它们进行评估，然后在系统级仿真中使用所有这些抽象。我们表明，提出的BF-PDCCH在网络吞吐量方面取得了显着改善，并且性能优于现有的算法，PDCCH和EPDCCH方案。