无线体域网中协作通信网的中继选择与功率分配

【作者】 李强；

【导师】 申东娅； 帅新芳；

【作者基本信息】 云南大学 ， 通信与信息系统， 2014， 硕士

【摘要】 随着无线通信技术与计算机技术的发展,无线网络已经被广泛的应用到了各行各业。而无线体域网的诞生,更是提高了人们的生活质量。但是随之而来的也产生了很多问题,比如如何才能高效的利用无线体域网网络,如何能让无线体域网的寿命更长等。因此,协作通信网络的引入,可以很好的解决上述问题,因为协作通信的空间分集可以有效的应对多径衰落,有效地提高了网络的可靠性,并且在一定程度上也提高了能源的利用率。它为无线体域网的研究开拓了一个新的领域,成为了无线体域网技术研究的热点之一本文主要研究了无线体域网中协作通信网络的节能与高效传输问题,具体到协作通信网络,就是研究它的中继选择与功率分配问题,论文的主要工作分为以下几个部分：首先,对无线体域网进行了简要介绍,引出无线体域网中协作通信网络,并简单介绍其网络结构与协作策略,对不同协作策略下的通信网络进行了对比。其次,将无线体域网的协作研究问题抽象到一路两跳放大转发(AF)协作通信网络中,研究了基于不同准则下的中继选择问题,在此基础上提出了新的中继选择方法,即在信源发送信息前,先对协作链路与直接链路进行比较,如果直接链路的信道情况优于协作链路,就采用直接传输方式,反之则采用协作链路传输。协作传输状态下,将进一步进行中继选择：①.根据阈值来选择出候选的中继节点；②.根据中继节点的位置信息来决定最后参与协作的中继节点。仿真表明,采用本文中继选择算法的系统信道容量明显好于其他中继选择方法,并且利用最优中继节点进行传输时,节约了信源的发射功率。最后,考虑到无线体域网节能问题,提出了对节点进行功率分配。在只有单中继存在的情况下,利用偏微分的方式解决功率分配问题,当中继节点为多个时,本文引入最优化方法——牛顿法,来解决信源与多个中继节点的功率分配问题。通过对其进行仿真比较,发现牛顿法在较少的迭代次数下就可以得到最优解,并且采用功率分配的方法可以有效的延长网络的使用寿命。更多还原

【Abstract】 With the development of wireless communication technology and computer technology, wireless networks have been widely applied to all walks of life. The birth of a wireless body area network can improve the quality of people’s lives. But the attendant also had a lot of problems,such as how to efficiently use the wireless body area network, how to make life longer with wireless body area network and so on. Therefore, the introduction of cooperative communication network can solve these problems, because the space diversity of cooperative communication can effectively deal with multi-path fading, effectively improve the reliability of the network, and to some extent also improves the efficiency of energy rate. It opens up a new area for the study of wireless body area network, and become one of the hot spots of wireless body area network technology research.This paper studies the wireless body area network transmission problems in energy-saving and efficient cooperative communication network, specific to the cooperative communication network, is to study its relay selection and power allocation problems, the main work of this paper is divided into the following sections:Firstly, the wireless body area network for a brief introduction, leads to a wireless body area network in cooperative communication network, and a brief introduction of its network structure and collaboration strategy, communication networks under different collaborative strategies were compared.Secondly, the research questions of wireless body area network abstraction to the way the two-hop AF cooperative communication network, the research based relay selection problem under different criteria and conduct a simulation comparison; based on this proposed new relay selection method, that is, before sending the information source, the first collaborative links with a direct link to compare, if the channel condition is better than a direct link collaborative link, then the use of direct transmission mode, and vice versa using collaborative links. if using collaboration, then the second step would then need to relay selection:①According to the threshold to select the candidate relay node;②relay node based on the location information to determine the final relay nodes collaborate to participate more. Through MATLAB simulation comparison, found that relay selection algorithm with this paper, the system transmission rate is much better than other relay selection method, and using the optimal relay nodes to transmit, save the source of transmission power.Finally, considering the wireless area network energy saving problem, the power allocation of nodes are proposed. In the case of the presence of only a single trunk, you can take advantage of the way to solve partial differential power allocation problem, but if it comes to participating in cooperative multiple relay nodes, simple partial differential approach can not effectively solve the problem at the same time, so use optimization method-Newton’s method to solve the problem of power distribution source and multiple relay nodes. Through its simulation, power allocation can be found effectively extend the life of the network.更多还原