基于调度优先级的MAC协议设计及OPNET仿真分析-通信与信息系统专业论文.docx

摘要 本文的主要研究目标是设计分别适用于认知无线网和智能电网的基于调度优 先级的 MAC 协议。目前，认知无线网的研究主要是在物理层和 MAC 层上，而 MAC 层中最为关键的问题是 MAC 协议的设计。此外，随着低碳经济的兴起，智 能电网成为当前的研究热点。智能电网要做到实时掌握系统特征参数的变化，诊 断预测故障，就需要一种能有效传输多种业务且反应快速的通信系统。因此，如 何设计可以实时高效调度多种业务的 MAC 协议成为一大难题。 首先，本文为认知无线网设计了一种基于传输优先级和 CSMA/CA 的多信道 MAC 协议。该协议利用一个公共控制信道来协商频谱授权用户（主用户）和非授 权用户（次用户）对数据信道的使用权。通过对 CSMA/CA 机制中帧间间隔和退 避算法的改进，主用户可获得数据信道的优先使用权。此外，该协议利用一个中 心控制器来记录协商信息并分配数据信道，从而解决隐藏终端问题和频谱感知问 题。本文还利用马尔科夫链模型和非强插优先级排队模型分别对网络归一化吞吐 量和包的时延性能进行了仿真分析。 其次，无线局域网(WLAN)以其灵活性、宽带化、移动性等特性，将成为智能 电网通信技术的主流。本文在无线局域网的 MAC 协议的基础上提出了一种用于智 能电网信息传输的基于动态传输优先级的 MAC 协议。本协议利用自学习算法计算 下一时隙的传输业务量及传输速率，进而计算决定每种业务传输优先级的仲裁间 隔文章最后利用 OPNET 平台仿真分析了改进 MAC 协议及 WLAN MAC 协议的平 均吞吐量、时延及功率消耗等性能。 关键词：认知无线网 智能电网 WLAN MAC 协议 CSMA/CA 动态优先级 OPNET Abstract This paper researches on designing MAC protocol based on scheduling priority for cognitive radio network and smart grid network. Recently, cognitive radio network (CRN) has been considered as a key technology, in which physical layer and MAC layer are researched mainly. Moreover, with the rise of the low-carbon economy, the smart grid becomes a research hotspot. To achieve system characteristics in time, smart grid needs an effective transmission of multiple services and rapid response communication system. How to design an efficient real-time MAC protocol has become a major problem. Firstly, in this paper, a priority and CSMA/CA enabled MAC protocol for (CRN) is proposed, under which secondary users (SUs) access channels with lower priority than primary users (PUs) without spectrum sensing. The proposed PACE-MAC enables SUs to best utilize the unused frequency spectrum while avoid the collisions among SUs and between SUs and PUs. We develop a Markov chain model and a non-preemptive priority queuing to rigorously study the throughput and packet delay performance evaluation. Extensive simulations are given to analyses the performance of our proposed protocol. Then, WLAN will become the main trend of smart grid network communication technolo