Based On TL-138 Platform Research And Implementation Of High Mobility Wireless Communication Technology

High mobility short-burstcommunication is widely used in unmanned aerial vehicle communicationsand other fields in which the transmission time is short,the access time is random,the length of short-burst packet is small and the relative speed is high.Existing large Doppler frequency shift in high mobility short-burst communication results in high Bit Error Rate in the receiving end and even leads to disorder in the receiver demodulation having a bad impact on the performance of communication system.Therefore awide scale offrequency offset correction is a key technology of high mobility short-burst communication.This paper proposes a frequency offset correctionalgorithm of MDPSK system under High mobility short-burst communication.The work of this paper is mainly embodied in the following aspects:(1)This paper firstly introduces the research background of the high mobility short-burst communication environment and the significance of frequency offset correctionalgorithms,and then the research status of frequency offset correctionalgorithms are reviewed,then the core device of the system hardware platform is summarized.(2)In high mobility short-burst communication,the produce principle of Doppler frequency shift in the received signal is analyzed.The brief analysis of the 4 DPSK and QAM modulation and demodulation process is introduced,and then this paper discusses that the Doppler frequency shift has a significant impact ondemodulation side of 4DPSK and QAM: leading to frequency spectrum shifting after down-conversion which leads to a dramatic increase in Bit Error Rate,and even leads to demodulation disorder.Frequency offset correctionalgorithms in high mobility short-burst communication environment are discussed in detail,including Kay algorithm,Fitz algorithm,M&M algorithm,etc.And then the performance of the various methods to obtain the correct carrier is analyzed,but traditional way for carrier locks Doppler frequency shift is too slow in whichthe range of frequency offset correction is narrow and computation complexity is high.(3)This paper proposes a frequency offset correctionalgorithm of MDPSK system under High mobility short-burst communication,and the algorithm in the 4 DPSK,8 DPSK and star 16 QAM implementation process has carried on thoroughly.Comparing to the traditional frequency offset correctionalgorithms,in the same conditions,the frequency offset correctionalgorithm of MDPSK system under High mobility short-burst communicationproposed in this paper has many advantages:short length ofpilot,large range of frequency offset correction,low computation complexity,etc.In short-burst communication,based onthe frequency offset correctionalgorithm proposed in this paper,a method to shorten the length of pilot through calculation is proposed.(4)The system implementation platform TL138 and so on has carried on the simple introduction.And development steps in the CCS integrated development environment has carried on the brief description.Thenthe configuration files of GEL and CMD is introduced,andthe design of the configuration files are carried on.Later in this paper,each module of the system implementation is designed,including the design of the sender,the design of the interface,the design of the FIR low pass filter,the design of the receiver with frequency offset correction.Finally Burning program after cross-compilation into development board.Therefore the hardware implementation validates the correctness and validity of the frequency offset correctionalgorithm of MDPSK system under High mobility short-burst communicationproposed in this paper.