A Research Of Multi-Robot Communication Platform Based On Spread Spectrum

With rapid development of the wireless communication and the robot technology, spread-spectrum technology based multi-robot communication system has become the product of combining these two technologies. Due to the special requirements of real-time performance, reliability and confidentiality in Multi-Robot Communication System, the research of communication platform which is suitable for Multi-Robot System has great significance.This paper is about the designing and development of an DS spread spectrum communication system. It adopts time FDD and CDMA to realize the communication of data and image between one point and many points. This paper is concentrated in designing and realization of the digital baseband of the DS system.First, the status quo of multi-robot system research at home and abroad is reviewed.Also,the significance of multi-robot communication system research is introduced. Second, several essential problems of multi-robot systemare expounded.On the basis of the theory,multi-robot communication platform is deeply studied, such as the designing of transmission system, the realization of send module and receive module.Then, we deeply study the performance of PN code.The selection and constitution of spread spectrum sequence is one of the key technologies in design of spread spectrum communication system. After analyzing the drawbacks of PN sequence,a modified m-Walsh sequence is proposed.In this thesis, we simulate the relation characteristic of m-sequence, walsh code and modified m-Walsh sequence.From performance analysis and computer statistics,we can conclude that the new sequence has a good performance which is fit for the communication platform.On the basis of the simulation result,an improved Rake receiver scheme is proposed,the BER performance of which is simulated in three kinds of channel with MATLAB/Simulink.The experimental results prove that the communication platform is exactly apply to UMTS (Universal Mobile Telecommunication System) which is affected by severe multipath interference.Finally, the problems in the experiment are analyzed, some new advanced implement method and suggestion are given for the further improving of this system.