The Design And Implementation Of Ad-hoc Network Terminal With Narrowband And Broadband Fusion

In the era of rapid development of wireless communication network,the need to rely on center base station control,centralized management,fixed communication facilities of communication network,yet cannot satisfy wireless communication diversification needs.Especially in some special cases of complex environment,such as disaster relief emergency deployment of wireless communication network,maintaining stability and dealing with emergencies in large groups,firemen need to maintain the emergency communication and on-site scheduling,etc.In this scenario,there is no pre-existing network communication infrastructure,and even the site's fixed infrastructure has been destroyed and cannot be used at all.At this time,the mobile communication terminal which supports the narrowband and broadband fusion of communication service can be the urgent need of the scene.This thesis designs the narrowband and broadband fusion of lightweight and portable ad-hoc network communication terminal,which is a kind of multi-mode communication terminal,not only has high efficiency of wireless transmission performance,low power consumption,and broadband transmission rate,but also can be used for narrowband anti-jamming voice transmission.The ad-hoc network communication terminal can quickly form a no-centre,self-organizing network LAN communication on the ultrashort wave spectrum when brought into the complex environment of no commercial signal coverage area,realizing long-distance cross-barrier communication and anti-jamming communications.The ad-hoc network communication terminal can support the information transferring and sharing between the temporary emergency centers,people,and sensor node of information perception throughout the site.The Ad-hoc network communication terminal is specifically designed for emergency communication application environment,and it is especially suitable for complex terrain communication environment.Based on the establishment of the communication platform protocol stack model,this thesis studies the hierarchical design of Ad-hoc network communication terminal with narrowband and broadband fusion,which mainly includes:1.We designed communication terminal waveform,namely broadband Ad-hoc waveform design and narrowband anti-jamming design of waveform.The physical layer on Ad-hoc waveform designing orthogonal frequency division multiplexing modulation technology,can effectively compensate the multipath fading and Doppler shift effects.Adopting the adaptive modulation coding technology,the maximum throughput rat e of the current link quality is realized by automatically selecting the maximum modulation code available according to the quality of the communication link.The MAC layer adopts the carrier interception multiple access/conflict avoidance protocol to guar antee the reliability of reciprocal communication in the case of shared channel resources.In the design of narrow-band low interception and low detection anti-jamming waveform,the design scheme of super-long sequence spread spectrum based on hopping code is adopted.2.We designed routing protocol,which mainly introduces the design idea of AODV protocol and OLSR protocol.Through the NS2 simulation platform,we compare the performance on three parameters: the average transmission delay,routing overhead and network throughput in the given environment.3.We conducted the system testing and validation.This thesis introduces the application of android intelligent testing terminal application,and it describes their business data transmission process of wide/narrow by describing the structure of the software and hardware design block diagram and the underlying driver design.The feasibility of the design and development of the communication terminal is verified through the test of network functions and transmission rates in the indoor and outdoor environment.