Low-Latency Relaying for Future Wireless Networks

未来的无线通信系统预计将支持超过每秒数十兆比特的超高数据速率的可靠传输，同时具有小于1毫秒的低延迟。同时满足这些要求是一项重大挑战，也是地球仪许多研究小组的焦点。 在使未来无线网络的目标能够实现的最有效和最具成本效益的技术之一是被称为无线中继的中间通信辅助节点的部署。继电器可以根据其中继技术进行分类。这些技术包括放大转发（AF）、解码转发（DF）和压缩转发（CF）。继电器还可以基于其操作模式进行分类，例如，半双工或全双工，和/或它们的底层通信协议，例如，单向或双向。为了有效地使用继电器，它们的配置必须考虑通信场景。例如，当发射机-中继信道明显强于中继-接收机信道时，DF中继策略是最优的。然而，当发射机-中继信道不满足该条件时，DF中继可以被其他中继技术取代。以互补的方式，全双工和双向中继通常比其各自的半双工和单向中继更有效，但它们引起更高的计算复杂性和实现挑战。中继节点可以提供给网络的性能优势主要取决于网络拓扑结构、传播环境和操作信噪比。 该研究计划的重点是探索中继技术的增强和实用性，以满足未来无线延迟和安全敏感应用所带来的严格限制，例如，自动驾驶汽车和物联网（IoT）。本研究计划将考虑以下方向： 方向一：研究了AF、DF和CF中继技术在常规无线信道条件下，但在实际时延约束下的性能。 方向二：探索中继技术的实用性，例如，AF、DF和CF，以及操作模式、全双工和半双工，当无线信道表现出时间和空间相关性时。将考虑单向和双向中继网络。 方向三：探索最佳中继在快速车辆通信中的信道是未知的接收机和严格的延迟约束下的最佳中继尚未开发。 这些方向将为全球减少无线网络延迟同时提高其可靠性和吞吐量的努力贡献重要的创新元素。这些方向也将作为一个平台，培训高素质的人员谁愿意承担领导作用，在无线通信竞技场。

Future wireless communication systems are expected to support the reliable transfer of ultra high data rates exceeding tens of Gigabits per second with low latency of less than one millisecond. Meeting these requirements simultaneously comprises a major challenge that form the focal point of many research groups around the globe. Among the most efficient and cost-effective techniques to enable the goals of future wireless networks to be achieved is the deployment of intermediate communication-assisting nodes known as wireless relays. Relays can be categorized based on their relaying technique. These techniques include amplify-and-forward (AF), decode-and-forward (DF) and compress-and-forward (CF). Relays can be also categorized based on their operational modes, e.g., half-duplex or full-duplex, and/or their underlying communication protocols, e.g., one-way or two-way. To make effective use of relays, their configuration must take into consideration the communication scenario. For instance, when the transmitter-relay channel is significantly stronger than the relay-receiver channel, the DF relaying strategy is optimal. However, when the transmitter-relay channel does not satisfy this condition, DF relaying may be superseded by other relaying techniques. In a complementary fashion, full-duplex and two-way relays are generally more effective than their respective half-duplex and one-way relays, yet they invoke higher computational complexities and implementation challenges. The performance advantages that relaying nodes can offer to a network depend primarily on the network topology, the propagation environment and the operational signal-to-noise ratios. The focus in this research program is to explore the enhancement and utility of relaying techniques to meet the stringent constraints imposed by future wireless delay and security sensitive applications, e.g., autonomous vehicles and Internet-of-Things (IoT). This research program will consider the following directions: Direction I: Studying the efficacy of AF, DF and CF relaying techniques under conventional wireless channel conditions but with practical delay constraints. Direction II: Exploring the utility of relaying techniques, e.g., AF, DF and CF, and operational modes, full and half duplex, when the wireless channel exhibits temporal and spatial correlation. Both one-way and two-way relay networks will be considered. Direction III: Exploring optimal relaying in fast vehicular communications wherein the channel is unknown to the receiver and optimal relaying under stringent delay constraints has yet to be developed. These directions will contribute important innovative elements to the global effort to reduce latency of wireless networks while enhancing their reliability and throughput. These directions will also serve as a platform for training highly qualified personnel who are ready to assume leadership roles in the wireless communications arena.