电容耦合体域网的高能效协作接入机制研究

Sensors and portable teminals within the body area can be interconnected in Body Area Network(BAN) with the body channel communication technology. BAN is important in mobile medical and remote health monitoring. The body channel communication technology takes the human body as the communication channel and it can be classfied as antenna coupling, galvanic coupling and capacitive coupling.To overcome the high loss properties of human tissue, the radiation field should be increased in antenna coupling and it is not conductive for the safety of the human body. Low working frequency in galvanic coupling makes it can only achieve a low rate transmission. Capacitive coupling has the characteristics of low radiation, high rate transmission etc and it becomes the current research hotspot. The study of multi-point network with capacitive coupling just starts while point-to-point communication has obtained many achievements. And the main difficulty is the energy efficiency in the human body channel access of near field communication. With the game theory to model the competition and cooperation among nodes according to the strong asymmetry of the power cost between the sender node and the receiver, this project researchs on the collaborative access mechanism with energy efficiency in capacitive coupling BAN. Research contents include: 1)collaborative time slots allocation mechanism with energy efficiency. 2) collaborative anti-collision mechanism with energy efficiency. 3) implementation mechanism of distributed collaborative access. 4) the simulation and experiment platform. The applicant and the project members are long engaged in the research on short distance wireless access technologies, collaborative resource allocation theory. Our preliminary achievements are published in domestic or international publications.

体域网用人体通信技术实现人体范围内传感器或终端的互联，是实现移动医疗和远程健康监护的重要环节。人体通信技术以人体为信道传输信号，根据信号耦合方式可分为天线耦合、电流耦合和电容耦合。天线耦合方式因克服人体组织的高损耗特性需增大辐射场，辐射大不利于人体安全。电流耦合方式工作频率低，只能实现低速率传输。电容耦合方式具有低辐射、高速率等特点，是目前的研究热点。电容耦合点对点人体通信技术已有较多成果，但是多点组网的研究刚起步，主要难点是近场通信中人体信道接入的高能效问题。本项目根据人体信道收发端功耗的强不对称性，用博弈论对节点接入的竞争与合作关系建模，研究电容耦合体域网的高能效协作接入机制，研究内容包括：1高能效协作时隙分配机制2高能效协作防碰撞机制3分布式协作接入的实现机制4软件仿真和实验平台搭建。申请人及项目成员长期从事短距离无线接入技术、无线网络协作资源分配理论研究，完成了一系列高水平论文。

体域网是实现人体范围内传感器或终端互联，是实现移动医疗和远程健康监护的重要环节。天线耦合方式因克服人体组织的高损耗特性需要增大辐射场，辐射大不利于人体安全，故传统无线通信技术在人体通信应用场景受到很大局限。电容耦合方式通过电极在人体表面诱导感应电场实现信号耦合，信号沿体表和空气交界面传输，信道由人体组织和空气共同组成，受人体内部环境影响小，传输速率可达10Mbit/s。点对点电容耦合人体通信技术已有较多成果，但是多点组网的研究刚起步，主要难点是近场通信中人体信道接入的高能效问题。此外，超声在医疗领域中应用了数十年，在长时间临床应用中经证明对人体无害，且超声在人体内的衰减比传统无线电小，可作为人体通信的载体，但体内超声通信面临着明显的多径问题。体域网体内节点所处位置决定充电不方便，功耗是决定网络生存周期的关键因素，信能同传技术为延长体内网络的生存周期提供了技术支持。本项目围绕人体信道的特殊性，引入博弈论研究了电容耦合体域网的低功耗协作接入方法、协作传输、信息和能量携同传输机制，提出了协作接入的新方法；研究了超声体内信息传输的可能性和信道编、译码的可实现方案。研究成果主要包括：（1）针对电容耦合体域网，提出了基于自适应轮询的低功耗体域网的分布式接入控制方法；（2）针对体内异构环境，提出基于联盟形成博弈论的协作速率分配；（3）针对不同应用场景，提出多种移动式自适应能量与信息同步无线传输方法；（4）通过建模和仿真，分析体内超声信道的传输特性和体内超声通信的可行性；（5）针对多径问题，提出一种混合修正加权比特翻转的LDPC译码算法。结果证明通过协作接入和协能通信提高体域网的生命周期是可行的，超声体内通信是可行的，相关成果在国内外期刊发表论文5篇，标明资助5篇，含SCI/SCIE收录期刊论文3篇，EI收录期刊论文1篇，提交发明专利19件，其中授权2件，提交实用新型专利3件，其中授权3件，如期完成计划目标。