Research On Smart Antenna Based Mac Protocol Of Wireless Ad Hoc Networks

With the popularity of personal data communications, wireless Ad Hoc network technology is more widely used,it is to access the flexibility, mobility and personal autonomy as an important part of communication. At the same time the requirements of users for data services is also increasing, in order to meet this business demand, people are constantly introducing new technologies and methods to improve the capacity of wireless communication systems. Smart antenna technology is an effective way to improve wireless channel performance, increase system capacity of wireless communication technology, it has become the third-generation wireless communication systems is a key technology, how to effectively incorporate smart antenna technology into the wireless Ad Hoc network research has become a hot issue.Wireless network media access control protocol (Medium Access Control MAC) for multiple users on how to solve the problems shared channels, the performance of its wireless network system has a decisive influence. Good MAC protocol should be designed to ensure that any business has a high load conditions throughput, low delay and low overhead. Traditional wireless Ad Hoc network MAC protocol working mechanism is based on the node to all the work to the antenna under the mechanism, if the introduction of a directional antenna to a wireless Ad Hoc networks, because of directional antenna with directional antenna will give all the agreements to bring some negative impact on the working mechanism. In order to effectively use directional antenna space division multiplexing features, while reducing some of its directional influence to bring the need to propose a new wireless MAC protocol. For the directional antenna and wireless channel characteristics, there are many directional antenna based access control protocols have been proposed to achieve channel spatial reuse. In this paper, smart antenna technology and its applications in wireless communications, analysis of some representative of the use of smart antennas for wireless access protocol. Finally, according to the characteristics of wireless Ad Hoc networks and some of the advantages of smart antenna design a smart antenna based on slot MAC protocol( Time Division Scheduling,TDS-MAC) design. Through the single channel is divided into control and data on the period of time in self-scheduling control design to improve the wireless channel communications environment, improve air on radio channel division multiplexing. And using OPNET simulation tool to achieve the agreement of modeling and simulation, and use it all the antennas and smart antennas IEEE802.11 protocol network made MMAC protocol performance comparison. The simulation analysis shows that the agreement achieved by using smart antenna channel spatial reuse, making the system throughput has improved dramatically, but also address the use of smart antenna brought new problems.