【作者】 郎赫；

【导师】 龙承念；

【作者基本信息】 燕山大学 ， 控制理论与控制工程， 2009， 硕士

【摘要】 随着微电子系统和高集成低能耗的数字电子电路的发展,新的无线通信技术在不断地涌现。其中无线ad-hoc网络和无线传感器网络是两种具有代表性的网络,这两种网络以及在它们基础上发展起来的协作分集技术,已经引起了人们广泛的关注。然而,这两类网络的独有特点也给相关的网络设计和管理提出了挑战。第一,在无线传感器网络中,需要对节点能量进行很好的管理和分配,以延长网络寿命;第二,在无线ad-hoc网络中,由于所有的节点是分布式的,而且节点的合作需要消耗自身的资源,所以个别的节点会采用拒绝和网络中其他节点合作的方式来节省自身的资源,因此关于无线ad-hoc网络中节点的不完全合作行为的研究是十分必要的。针对以上的问题分析,本文分别对无线传感器网络中采用协作分集方式通信的节点的功率优化分配问题和无线ad-hoc网络中协作分集系统节点的自私行为和性能进行了研究。首先,研究了无线传感器网络中在各个节点完全合作条件下,采用两种协作通信策略的节点功率优化分配问题。本文针对采用协作分集方案下的节点能量消耗问题提出了一种非线性模型,并利用粒子群优化算法来获得最优的功率分配值。结果表明,随着合作节点的增多,单个节点的能量消耗减少,有效地提高了网络的生存时间。其次,研究了ad-hoc网络环境下放大发送(AF)的合作分集系统中,中继节点不完全合作的误码率性能问题。采用开关(on-off)模型来描述中继节点的自私行为。分别研究了存在单个和两个中继节点在不完全合作条件下的误码率性能,并提出了根据节点自私概率门限值来选择协作方案的终端选择方法。仿真结果验证了分析的正确性。更多还原

【Abstract】 With the developments of micro-electro-mechanical systems and low power-consuming integrated digital electronics, new technologies have emerged continuously. Wireless ad-hoc network and wireless sensor network are two representative networks. The two networks and cooperative diversity technology based on which have bring up a prevalent attention. However, the special characteristics of the networks have also posed many challenges to the design and management of the interrelated networks. First of all, in WSN, we need to allot and manage the energy effectively. Second, in ad-hoc network, all the nodes are distributed. Furthermore, the cooperation demands the nodes to expend energy on helping other nodes, so some individuals may refuse to cooperate with other nodes in the network to save their energy. Therefore, research on the partial cooperative behavior is necessary.In this paper, we do some work about the power allocation of cooperative nodes in wireless sensor networks and selfishness and performance in wireless ad-hoc networks.First, we assume that all the nodes in the wireless sensor networks are cooperative. Then we study the problem of optimal power allocation among the nodes with two cooperative communication schemes. We proposed a nonlinear model for the energy consuming with cooperative method, then we use particle swarm optimization (PSO) to achieve the optimal power allocation. The result shows that the power consuming of single node decreased with the increasing cooperative nodes. The lifetime of the whole network is prolonged effectively.Second, we study the problem of the performance of bit error rate (BER) in case of partial cooperation with amplify-and-forward method in ad-hoc networks. We use on-off model to describe the selfish behavior of the relays. Then we analyze the performance of BER with one and two relays, which are selfish nodes. We proposed a method that the terminal can choose the cooperative scheme according to the critical selfish probability of nodes. Simulations validate our analysis.更多还原