基于信号特征的无线传感网共存理论与关键技术研究

Various wireless technologies adopted in different Internet of Things applications are filling the human living space. It is becoming common that different wireless networks following different standards and protocols operate in the same physical area, which is called coexisting environment. The coexisting networks interfere with each other when they operate on the overlapped frequency and therefore cause significant performance degradation of wireless sensor networks (WSN). The coexisting problems hinder the broader development of WSN. Based on our measurements of the WSN systems deployed in coexisting environments, we observe serious coexisting problems such as disability of interference identification, energy inefficiency and transmission unreliability. To solve these coexisting problems, we carry out this research on exploiting signal signatures for coexisting theory and techniques in WSN. First, we study the intrinsic features of wireless signal and design a low-cost universal interference classification method to enable resource-limited sensor nodes to have the ability of identifying coexisting interference in a short time. Then, we further propose a new low duty-cycle energy management mechanism that avoids the false wakeup problem by waking up nodes only when a valid ZigBee signal is detected. Due to the robust recognition of ZigBee signal, this new energy management mechanism is resilient to heterogeneous interference. The proposed method can extends system lifetime and improves the usability of WSN under coexisting environments. At last, we study the channel correlation under coexisting environments and design a correlation based channel-hopping strategy. The proposed method improves data reliability and maintains the high efficiency of WSN under coexisting environments.

使用各种各样无线技术的物联网应用正不断进入人们的生活空间，逐渐形成多网络多协议运行在同一空间的共存环境。由于无线信号的广播特性，运行在相同频段上的无线技术会产生共存干扰，使无线传感网出现性能严重下降的共存问题，制约无线传感网在越来越普遍的共存环境中应用和发展。本项目拟针对实际系统在共存环境中发现的干扰难辨、能量管理失效和传输效率降低这三个共存问题，开展基于信号特征的无线传感网共存理论和关键技术研究。首先，本项目拟利用低成本的信号本质物理特征，研发普适可靠的多制式共存干扰辨识技术，突破资源受限节点对共存干扰短时难辨的瓶颈。然后在此基础上，建立首个基于有效信号识别的低功耗工作框架，研究异质干扰免疫的能量管理机制，保障无线传感网在共存环境中的可用性。最后，提出基于信道相关性的跳频策略，打破未探索信道状态不可知的传统思维，优化数据传输可靠性，提高共存环境中无线传感网的高效性。

使用各种各样无线技术的物联网应用正不断进入人们的生活空间，逐渐形成多网络多协议运行在同一空间的共存环境。由于无线信号的广播特性，运行在相同频段上的无线技术会产生共存干扰，使无线传感网出现性能严重下降的共存问题，制约无线传感网在越来越普遍的共存环境中应用和发展。本项目拟针对实际系统在共存环境中发现的干扰难辨、能量管理失效和传输效率降低这三个共存问题，开展基于信号特征的无线传感网共存理论和关键技术研究，同时开展了探索性的异构无线网络间跨协议直接互联的研究，并取得了一定的成果。本项目提出了多制式共存干扰辨识技术，并设计了异质干扰免疫的低功耗传输方法；发现了共存干扰非均匀功率谱密度会导致相关信道出现相反的信道状态这一现象，并基于此提出了基于量化信道相关性的低功耗无线网络自适应跳频技术；研究了跨协议直接互联理论和传输框架，拓展了共存的无线网络互联互通的能力。我们取得了一系列具有较强创新性的研究成果，发表了学术论文16篇，包括IEEE/ACM Transactions、CCF A类等一流学术期刊和会议9篇；申请并获得授权发明专利6项。项目的研究达到并超过了预期的目标。