协同分集与多包接收相结合的分布式并发无线通信关键技术研究

As the data communication demand increase quickly, the available wireless network technologies cannot meet the requirement for future applications. The capacity of a modern wireless communication system is interference-limited. Multi-packet reception (MPR) is a promising progress at the physical layer to combat the interference. We have studied the design of MPR techniques for several years and find that, as the available MPR techniques only take advantage of the packet reception capability at a single node, there are strict constraints for feasible simultaneous transmissions. To improve and effectively utilize the MPR capability in wireless networks, we will study the design of a distributed cooperative communication system. (1) We propose a novel cooperative diversity-based MPR technique and design the node cooperation mechanism, i.e., cooperative partner selection etc., according to the requirements of concurrent transmission. (2) In order to build a distributed access control scheme, we establish a fine-grained channel state model, propose a powerful channel sensing mechanism to accurately capture the channel condition, and design a distributed policy to coordinate the link transmissions with interference tolerance to some extent. Our work will finally present a novel communication system, by integrating cooperative diversity and multi-packet reception, to effectively support the simultaneous transmissions by user cooperation and fine-grained channel characterization. It has the great potential to efficiently utilize the wireless channel resource and provide high network performance.

现有无线网络无法满足日益增长的通信需求。干扰是制约无线网络性能的主要因素，多包接收是处理干扰的重要思路，课题组在这方面已取得部分研究成果。但现有多包接收技术仅利用了单点的接收能力，存在严格的并发约束。本申请围绕网络视角下如何提高并充分利用多包接收能力的问题，结合无线网络环境提供的协作机会，研究新型分布式并发无线通信机制的关键技术：(1) 研究基于协同分集的多包接收技术，设计支持并发传输的协作策略，从而建立协同分集与多包接收相结合的并发传输机制；(2) 探索细粒度的信道刻画与感知机制，设计并发无线通信的分布式接入控制策略。本申请立足于无线传输技术的最新进展，突破单点多包接收能力的局限性，提出利用协作促进并发的新思路；突破传统的信道忙/闲二值状态模型的局限性，提出利用细粒度信道状态信息支持并发通信的新思路。研究成果将为充分利用无线信道、显著提升网络性能提供新的技术途径，具有良好的应用前景。

从无线信道的本质特征出发，围绕网络视角下如何提高并充分利用多包接收能力的问题，本课题研究了无线并发通信的新技术，探索了无线信号的新应用。首先，面向干扰抵消，研究建立面向干扰抵消的干扰模型及信号接收模型，揭示了支持SIC的无线网络在调度性能、网络容量等方面的规律，探索基于干扰管理的并发通信传输协议及调度算法。其次，无线网络的协调控制开销成为制约网络性能的关键因素。针对这一问题，提出了一种全新的3D流水竞争机制，它通过将竞争过程与传输并发进行，隐藏竞争的开销，从而大幅提高通信的效率。再次，面向无速率编码、极宽频通信等新型物理层技术，从物理信号接收、报文设计等角度，针对不同的媒体数据类型，探讨了高效无线传输机制的设计。最后，探索了无线信号的新应用拓展，运用无线信号处理、机器学习等技术，设计并实现了一个利用窄带无线信号，识别行为并评估其质量的系统 WiQ。该系统可分析并识别细粒度的动作特征，从而完成疲劳驾驶检测、驾驶员识别等复杂任务。项目的研究成果深化了对无线通信的规律的认识，拓展了无线信号的应用领域，为高效无线通信、普适的行为识别等提供了有效的解决方案，具有良好的理论意义与广泛的应用价值。