Design And Implementation Of Demonstration System For Cognitive Ad Hoc Network Based On Usrp

Due to the development of communication technology and the growth of communication service,the demand for spectrum resources is increasing,which makes wireless spectrum resources become an increasingly scarce resource.Cognitive radio technology can use spectrum resources flexibly which is an important way to solve the scarcity of spectrum.Therefore,studying and developing cognitive radio is very meaningful.Ad Hoc network is a distributed multi-hop network system,composed of equal standing communication nodes,it does not need the support of the base station or router and has strong resistance and robustness.In this paper,the two technologies have been combined.Cognitive radio is a kind of communication system which does not need fixed spectrum assignment and does not need fixed base station.It can use spectrum resources and decide routing intelligently,which can form network flexible.Based on them,a demonstration system scheme for CR Ad Hoc network is designed.The work is as follows:(1)Making a analysis to CR Ad Hoc network.This paper argues that CR Ad Hoc network should has the basic function of CR and Ad Hoc.The nodes in the system must have the ability to learn,and sensing the wireless spectrum environment,allocating the spectrum resources dynamically,the interference avoidance,the multi-hop communication,the topology discovery and the update and so on.(2)Designing the system structure and module function of CR Ad Hoc network demonstration system.According to the system function,I design the system structure:four kinds of node and five kinds of function module,And also I design a detailed flow chart for each function module.(3)Implementing and testing CR Ad Hoc network system.The demonstration system uses USRP(Universal Software Radio Peripheral)N210 equipped with WBX daughter board as the system hardware implementation platform.Based on the Linux system GNU Radio software development environment and using Python scripting language,the demonstration system program achieves the program design and programming.I designed and implemented dynamic spectrum resource allocation module,interference avoidance module,multi-hop communication module and other functional modules.By doing the functional module test experiment and the system comprehensive test experiment,I verified that the functional modules can run correctly,and prove that the present demonstration system has strong network topology connectivity and network survivability.Through the research work of this project,we can accumulate the experience of CR Ad Hoc Network to provide the appropriate platform and auxiliary for the study of cognitive ad hoc networks.