Performance Analysis and Optimization of Future Low Latency and Reliable Cooperative Communication

随着低延迟和高可靠性成为未来无线网络设计的两大关注点，各种技术被提出、研究和改进以满足这些要求。其中，中继是众所周知的利用空间分集来缓解无线衰落的有效方法。然而，几乎所有关于中继优势的现有研究都是在香农信道容量下任意可靠通信的理想假设下进行的，即假设所谓的无限块长制度。由于低延迟要求较短的块长度，这会导致解码错误，降低可靠性，因此研究有限块长度下中继的行为对未来低延迟和可靠网络的设计至关重要。在本提案中，我们的目标是通过利用有限块长度制度的新性能模型和优化技术，为低延迟和可靠的中继系统的性能分析和系统设计做出贡献。更重要的是，我们考虑了更现实的系统模型，例如有限块长度，不完美CSI和衰落信道模型，这使我们能够从我们的结果中推断出更合理可靠的系统设计指南。首先，我们将在上述实际系统模型下对单中继网络的性能进行详细分析。然后，我们将单中继网络的所得结果推广到多中继网络。最后，利用对有限块长度中继的分析见解，我们打算通过最小化错误概率和最大化qos约束容量来设计有效的qos约束和可靠的中继网络。

As low-latency and high reliability become two major concerns in the design of future wireless networks, various technologies are proposed, studied and improved to satisfy these requirements. Among them, relaying is well known as an efficient way to mitigate wireless fading by exploiting spatial diversity. However, almost all the existing studies of the advantages of relaying are under the ideal assumption of communicating arbitrarily reliably at Shannon's channel capacity, i.e. assuming the so-called infinite blocklength regime. As low-latency requires short blocklengths which introduce decoding errors and reduce the reliability, it is essential to study the behavior of relaying in the finite blocklength regime to contribute to the design of future low-latency and reliable networks. In this proposal, we aim at contributing to the performance analysis and system design of low latency and reliable relaying systems by utilizing a novel performance model of the finite blocklength regime and optimization techniques. More importantly, we consider more realistic system models, e.g. finite blocklength, imperfect CSI and a fading channel model, which allows us to deduce from our results more reasonable and reliable guidelines for the system design in practice. First, we will provide a detailed analysis of the performance of single-relay networks under the above described realistic system models. Then, we will extend the obtained results for single-relay networks to multi-relay networks. Finally, by exploiting the obtained analytical insights into relaying with finite blocklengths, we intend to design efficient QoS-constrained and reliable relaying networks by minimizing the error probability and maximizing the QoS-constrained capacity.