Collaborative Research: Distributed Error Correction Strategies in Wireless Networks

多跳网络无线通信正迅速成为未来无线系统的主要架构，包括蜂窝和WiFi网络、网状网络和传感器网络的多跳扩展。这些类型的网络的共同之处在于，它们不是完全非结构化（或自组织）的网络，但流量路由和积累到一个共同的目的地。由于这种特性，这些网络被称为流量积累网络（NETAs）。由于交通负荷的增加和交通干扰的增加，交通集聚在共同目的地周围形成热点或瓶颈。尽管热点问题很严重，但缺乏有效的应对方法。本研究针对两种重要的子类-线网络和树网络，开发了新的分布式纠错策略，解决了NETAs中的热点问题。在线路网络中，研究人员研究了分布式信道编码协议的基本特性和设计，使用串行连接和基于原型的结构来增强目的地附近的纠错能力，同时不牺牲宽带效率。在树状网络中，几个源节点可能希望使用一个公共中继节点将它们的信息广播到多个目标节点，这些目标节点可能可以访问来自“无意中听到的”源消息的侧信息。研究人员探索了一种新颖的方法，其中每个源使用独特的流率代码传输到中继，而解码的消息使用高速率“嵌套代码”重新编码。此外，还考虑了层间问题，特别是有效信道接入和路由方案的联合设计以及所提出的编码方案。

Networked wireless communications over multiple hops is rapidly emerging as the main architecture of future wireles systems, including multihop extensions of cellular and WiFi networks, mesh networks, and sensor networks. Common among these types of networks is that they are not completely unstructured (or ad hoc) networks, but traffic is routed and accumulated towards a common destination. Due to this characteristic property, these networks will be referred to as Networks with Traffic Accumulation, or NETAs. Traffic accumulation creates hot sposts or bottlenecks around the common destination because of the increased traffic load and interference. Despite the severity of the hot spot problem, there is a lack of efficient methods to cope with it. This research addresses the hot spot issue in NETAs by developing new distributed error correction strategies tailored to two important subclasses- line networks and tree networks. In line networks, the investigators study fundamental properties and the design of distributed channel coding protocals using serially concatenated and protograph-based constructions to strengthen the error correction capability near the destination without sacrificing badwidth efficiency. In tree networks, several source nodes may wish to employ a common relay node to broadcast their information to multiple destination nodes which may have access to side information from "overheard" source messages. The investigators explore a novel approach where each source uses a distinctlow rate code for transmission to the relay, whereas the decoded messages are re-encoded using a high rate "nested code". In addition, interlayer issues are considered, in particular the joint design of efficient channel access and routing schemes together with the porposed coding schemes.