In urban areas, the network operators deploy small-cell sites and install a large number of base stations to support densely populated cellular users. A similar small-cell deployment in rural areas is not feasible for the operators, as it will significantly increase the capital expenditure, and the return on the investment will also be comparatively lower. Hence, the most feasible way to provide cellular connectivity to rural areas is the deployment of large-cell sites. However, the technology developed for International Mobile Telecommunications (IMT)-Advanced standard (or 4G) was evaluated for an inter-site distance of 1.732 km, making the large-cell connectivity required for rural areas an afterthought. For cellular last-mile rural connectivity to be a reality through IMT-2020 (or 5G), the key is to have future technologies supporting large cells. In large-cell sites, the users experience comparatively more path loss, and thus, have poor signal coverage. Further, compared to downlink, the transmission power in uplink is limited, and therefore, uplink transmissions define the coverage of the communication system. Motivated by this, we propose several coverage solutions for uplink, considering an extremely large-cell site scenario. We initially analyze the received signal-to-noise ratio with 4G/5G systems at various distances based on the link budget evaluation. At larger inter-site distances, we show that it is infeasible to achieve cellular coverage with the current 4G/5G specifications. We then propose enhancements related to the waveform, modulation and coding schemes, resource allocation, and power control mechanisms. We evaluate the proposed enhancements through system- and link-level simulations, and show a significant improvement in the coverage for cell-edge users. We also show that our proposed enhancements achieve close to two times the improvement in the network capacity when compared to the currently available 5G specifications.

在城市地区，网络运营商部署小型基站并安装大量基站以支持人口密集的蜂窝用户。对于运营商而言，在农村地区进行类似的小基站部署是不可行的，因为这会大大增加资本支出，投资回报率也会相对较低。因此，向农村地区提供蜂窝连接的最可行方法是部署大型蜂窝基站。然而，为国际移动通信 (IMT) 高级标准（或 4G）开发的技术被评估为 1.732 公里的站点间距离，使得农村地区所需的大蜂窝连接成为事后的想法。为了通过 IMT-2020（或 5G）实现蜂窝最后一英里农村连接，关键是要有支持大电池的未来技术。在大基站中，用户的路径损耗比较大，信号覆盖较差。此外，与下行链路相比，上行链路的传输功率是有限的，因此，上行链路传输定义了通信系统的覆盖范围。受此启发，我们提出了几种上行链路覆盖解决方案，考虑到一个非常大的蜂窝站点场景。我们最初基于链路预算评估分析了不同距离的 4G/5G 系统的接收信噪比。在较大的站点间距离上，我们表明使用当前的 4G/5G 规范实现蜂窝覆盖是不可行的。然后，我们提出与波形、调制和编码方案、资源分配和功率控制机制相关的增强功能。我们通过系统级和链路级仿真评估提议的增强功能，并显示小区边缘用户的覆盖范围显着改善。我们还表明，与当前可用的 5G 规范相比，我们提出的增强功能实现了近两倍的网络容量改进。