Enabling multi-service radio access networks with Massive MIMO

移动的通信网络在过去的十年中已经从提供语音和基本消息服务的系统发展为社会的组成部分，从而实现了从语音和视频通信、互联网接入、银行、物流、导航和紧急服务的丰富的服务集合。具有高性能数据中心设备的不断增长的客户群已经推动了对无线电接入网络（RAN）中的容量的需求。为了满足这一需求，研发部门已经推出了几代无线电接入技术，并在全球范围内推广，其中4G从2012年10月起在英国实现了真正的移动的宽带体验。最新的表现是5G，在2018-2019年完成标准化后在全球范围内部署。与4G RAN相比，5G RAN的关键技术差异之一是原生使用有源天线系统，以实现有限频谱资源的基站使用效率的前所未有的阶跃变化。有源天线系统（AAS，也称为大规模MIMO）受益于电路和电子技术的进步以及基带处理器中的低成本计算能力，以提供对包括蜂窝天线的多个天线元件的独立控制。这种更精细的控制水平使基站能够根据各个用户的条件对传输进行微调，并增强用户对传输的接收。对用户体验的净效应可以被描述为无限容量的感知，用户接收其服务所需的资源，从而增强服务和应用的响应能力。AAS研究和实施中令人印象深刻的第一步之外的挑战是能够解决新兴应用和服务，这些应用和服务在延迟，可靠性，覆盖范围和速度方面具有不同的连接要求。许多此类新用例，包括各种机器到网络通信、工业自动化和运输、紧急和关键服务，都必须使用相同的网络基础设施（包括基站和天线系统）来提供。到目前为止，还没有技术利用AAS的能力来实现这种多服务用例，因为研究和学术界的主要驱动力是容量和能源效率。“网络切片”的概念并没有考虑AAS的数字信号处理和架构，因此也没有解决这个研究挑战。这项研究计划将探索和提供AAS的多业务处理能力，能够平衡可靠性，覆盖范围和整体网络容量。具体来说，我们将调查的可行性和性能界限，这样的多服务RAN在提供混合类型的服务可持续地通过一个单一的物理基础设施。我们将确定与AAS的RAN的物理层上可实现的可靠性和容量之间的基本权衡因素，并设计处理方法，以有效地支持用户区分，同时保持网络容量。我们将与标准化机构和行业内的行业和学术利益相关者合作，推动已确定的解决方案的实际实现，并塑造技术的进一步发展。

Mobile communication networks have evolved over past decade from systems providing voice and basic messaging service to an integral part of society, enabling a rich set of services from voice and video communications, internet access, banking, logistics, navigation and emergency services. A growing customer base with highly capable data centric devices has fuelled a demand for capacity in radio access networks (RAN). To meet this demand, research and development has delivered generations of radio access technologies, rolled out globally, with 4G enabling true mobile broadband experience in the UK from October 2012. The latest manifestation, 5G, being deployed globally following the completion of standardisation in 2018-2019. One of the key technological differences in 5G RAN compared to 4G RAN is native use of active antenna systems to deliver an unprecedented step change in the efficiency of use by base stations of limited spectrum resources. Active antenna systems (AAS, also known as Massive MIMO) benefit from progress in circuit and electronics technology and low cost computing power in baseband processors to provide independent control over the multiple antenna elements comprising a cellular antenna. Such finer level of control enables basestations to fine-tune transmissions to individual user conditions and to enhance the reception of transmissions by users. The net effect on user experience can be described as a perception of infinite capacity, with a user receiving the resources that their service requires and consequent enhanced responsiveness of services and applications.The challenge beyond the impressive first steps in AAS research and implementation is to be able to address emerging applications and services carrying different connectivity requirements in terms of latency, reliability, coverage and speed. Many of such new use cases including various machine-to-network communications, industrial automation and transportation, emergency and critical services will have to be provided using the same network infrastructure, including the base stations and antenna systems. No technology exploiting capabilities of AAS for such multi-service use cases exists to date since the primary driver in research and academia has been capacity and energy efficiency. A concept of 'network slicing' does not address this research challenge either since it does not consider digital signal processing and architectures of AAS.This research programme will explore and deliver a multi-service processing capability in AAS, capable of balancing reliability, coverage and overall network capacity. Specifically, we will investigate the feasibility and performance bounds of such multiservice RAN in delivering mixed types of services sustainably through a single physical infrastructure. We will identify fundamental trade-off factors between reliability and capacity achievable on physical layer of RAN with AAS, and design processing methods to effectively support user differentiation while maintaining network capacity. We will work with industry and academic stakeholders within standardisation bodies and industry to drive the identified solutions to practical realisation and shape further evolution of technology.