In actual fact , a suitably modified amateur radio transmitter operating in either the 420 to 450 megahertz band or the 1 . 3 gigahertz band , with a highly directional antenna , is capable of transmitting voice to skull signals at less cost than the price of an automobile 事实上,一个适当限制在420到450兆赫波段或1 . 3千兆赫波段的带有高度定向天线的业余无线电广播发射机,能够把声音信号传给头骨并且所花的费用比一辆汽车的价格还要少。
This project takes the advantage of two techniques and overcomes their defects , which takes effect on pa linearization . on the aspect of networking antenna , this article discusses the application of smart antenna used in wlan , which makes it meet users " need in great area 最后本文介绍了wlan中的组网天线技术，分析了常见天线性能指标，对几种不同种类天线进行了性能分析与比较，并以某定向天线为例进行了结构和性能的分析研究。
The directional routing protocol ds _ dsr put forward by the author is the improvement of the current protocol dsr , complete routine discovery and maintenance by directional neighbor nodes routing table , source routing and directional steering . the research discovers the application of the directional antenna , compare the omnidirectional antenna can increases the networks " total throughput , obviously reduces the co _ channel interference ( cci ) , multiple access interference ( mai ) , enlarges the nodes " signal and interference to noise ratio ( sinr ) , and because of the high gain of directional antenna can realize the communication with farther distance and less jump , end to end delay can decrease deeply , simultaneously , security of networks can be improved partially , the node energy also can be saved easily by power control 本文提出的定向路由协议ds _ dsr是基于对现有协议dsr的改进下实现的，通过定向邻节点路由表、定向源路由和定向搜索来完成路由发现与维护。研究发现，定向天线的应用，相比全向天线可明显提高网络的总的吞吐量，减少信道干扰、多址干扰，提高信干噪比，且由于定向天线的高增益可实现较远距离、较少跳数的通信，减少了路由发现时间，这样大大减小了传输时延，网络的整体性能得到了不同程度的提高，同时部分地解决安全问题，通过功率控制还可较容易的实现节能的目的。
Previous research on the ad hoc network almost aim at omnidirectional antenna of all receivers and transmitters , or as a default attribution . in my thesis , firstly i describe the advantages of the directional antenna at many aspects which including spatial division multiple access ( sdma ) , the antenna gain , anti - interference etc . and analyze the possibility about the directional antenna used for the ad hoc networks , secondly i study its multiple access and routine protocols using the directional antenna . and compare the protocol difference and network " performance between omnidirectional and directional antenna in particular environment 首先阐述了定向天线在网络空分复用( sdma ) 、天线增益、抗干扰等方面的的优势，分析了定向天线用于移动自组网的可行性，接着重点研究了基于定向天线的多址接入协议和路由协议，分析了与全向天线在组网和协议实现中的异同点和优缺点，并对特定的环境下的网络性能作了对比。
For the sake of the convenient network simulation , i select a same framework in my mac and routine protocols " simulation , that is ieee802 . 11 standard built in soft tool opnet , by designing my network node model and directional antenna model , and the improvement of the current protocols , i realizes the evaluation of my special networks 为了方便网络协议性能仿真，使移动自组网的接入协议和路由协议能够在同一个模板上实现，本文在仿真平台opnet设计了ieee802 . 11框架下的移动自组网节点模型和定向天线模型等，并通过对现有协议的改进，实现了特定网络性能的计算机仿真。
