定向无线自组网吞吐量建模与忙音辅助接入协议设计

发布时间：2018-06-01 11:40

本文选题：无线自组织网络 + 定向随机接入　；参考：《南京航空航天大学》2017年硕士论文

【摘要】：无线自组织网络不需要固定基础设施支撑,组网快速灵活,抗毁性强,在军事和民用领域均有广阔的应用前景。研究人员将定向天线技术引入无线自组网,有效降低了信号冲突,提高了网络空分复用度和网络饱和吞吐量。然而,定向传输引起的“聋”问题和定向隐藏终端问题造成的数据冲突会对业务流的饱和吞吐量产生什么样的影响?如何针对定向无线自组网随机接入协议的饱和吞吐量进行建模与分析?如何进一步降低冲突,提升定向饱和吞吐量性能?现有的研究工作尚未能给出令人完全满意的答案。本文的研究工作即紧密围绕上述问题展开,取得的主要创新性成果包括:(1)提出了一种定向随机接入协议饱和吞吐量模型。本文首先分析了“聋”问题和定向隐藏终端问题导致的定向无线自组织网络数据传输冲突。然后,针对典型定向无线自组织网络随机接入协议D-MAC,提出了基于马尔可夫链的定向随机接入协议饱和吞吐量模型,为定向接入协议性能优化提供了理论依据。该模型通过计算任一时隙中节点向任一波束方向发送数据的概率及定向冲突概率,得出了网络饱和吞吐量的理论值。以该模型为基础,本文分析了定向天线波束数量、网络节点数量、随机退避竞争窗口等参数对网络总吞吐量的影响,并重点研究了给定网络拓扑条件下,由于数据传输冲突导致的不同业务流饱和吞吐量的差异性。仿真结果与数值结果的对比证明了模型的有效性。(2)设计了一种基于忙音辅助的定向无线自组织网络接入协议。该协议采用了忙音辅助策略避免“聋”问题和定向隐藏终端问题导致的数据传输冲突。节点通过发送全向RTS帧和定向CTS帧完成邻居之间的定向波束对准;在数据交互过程中,发送节点和接收节点通过定向发送“发忙音信号”和“收忙音信号”避免数据帧冲突,通过多波束定向发送“聋忙音信号”避免“聋”问题导致的数据帧的重传以及多条链路吞吐量之间的不公平性问题,并实现了网络中其余节点基于忙音侦听的并发定向数据传输。多种网络拓扑条件下的仿真结果证明,本文提出的忙音辅助策略能有效避免“聋”问题和定向隐藏终端问题导致的数据传输冲突,链路公平性和网络吞吐量性能优于传统的定向忙音辅助信道接入控制协议。
[Abstract]:Wireless ad hoc networks do not need fixed infrastructure support, fast and flexible networking, strong invulnerability, and have broad application prospects in both military and civil fields. The directional antenna technology is introduced into wireless ad hoc networks, which can effectively reduce the signal collision, improve the spatial division multiplexing degree and saturated throughput of the network. However, what effect will the data conflict caused by the "deaf" problem caused by directional transmission and the problem of directional hidden terminal have on the saturated throughput of traffic? How to model and analyze the saturated throughput of random access protocols in directed wireless ad hoc networks? How to further reduce conflicts and improve the performance of directional saturation throughput? Existing research has yet to provide a fully satisfactory answer. The research work in this paper is focused on the above problems. The main innovative results obtained include: 1) A saturated throughput model for directional random access protocols is proposed. In this paper, the problem of "deafness" and the problem of directional hidden terminal are analyzed firstly. Then, the saturated throughput model of directed random access protocol based on Markov chain is proposed for D-MAC, which provides a theoretical basis for the performance optimization of directional access protocols. By calculating the probability of transmitting data to any beam in any time slot and the probability of directional collision, the theoretical value of the saturated throughput of the network is obtained. Based on this model, the effects of the number of directional antenna beams, the number of network nodes and the random Backoff contention window on the total throughput of the network are analyzed in this paper. The difference of saturated throughput of different traffic due to data transmission conflict. The comparison between simulation and numerical results proves the validity of the model. (2) A new directional wireless ad hoc network access protocol based on busy tone is designed. This protocol adopts busy tone assistant strategy to avoid data transmission conflicts caused by "deafness" problem and directional hidden terminal problem. The node accomplishes directional beam alignment between neighbors by sending omnidirectional RTS frames and directional CTS frames. In the process of data interaction, the transmitting node and receiving node avoid data frame collision by sending "busy tone signal" and "receiving busy tone signal" by directionally transmitting "busy tone signal" and "receiving busy tone signal". Transmission of "deaf busy tone signals" through multi-beam orientation to avoid retransmission of data frames caused by "deafness" and unfairness between throughput of multiple links, And the other nodes in the network based on the busy tone listening concurrent directional data transmission. The simulation results under various network topologies show that the proposed busy tone auxiliary strategy can effectively avoid the data transmission conflicts caused by the problem of "deafness" and the problem of directional hidden terminals. Link fairness and network throughput performance are superior to the traditional directional busy tone auxiliary channel access control protocol.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5

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