Research on Adaptive Clock Frequency Offset Estimation Method for IR-UWB under Complex Multipath
In impulse radio-ultra wideband(IR-UWB)positioning system,clock frequency offset is an important factor affecting the accuracy of ranging and angular measurement.Aiming at the low accuracy of frequency offset estimation under complex mul-tipath,an IR-UWB adaptive frequency offset estimation algorithm for the complex multipath environment is designed.Firstly,with the advantage of anti-multipath of pulsed ultra-wideband signals,the real-time estimated channel impulse response as an adaptive matched filtering template is used to ensure the correct extraction of correlation peaks under complex multipath.Then,the phase se-quence of the leading symbols is obtained using the associated peak spoke angle information.Finally,Bayesian estimation algorithm is used to improve the accuracy of frequency offset estimation.The simulations were performed under the CM1～CM2 multipath chan-nels in IEEE 802.15.4a standard.The simulation results show that the accuracy of frequency offset estimation can be guaranteed within 0.2 ppm under low SNR.The experimental results in tunnel environment show that the standard deviation of frequency offset estimation is less than 0.06 ppm within the range of 50 m,which achieves the high precision estimation of frequency offset in complex multipath environments.It has a strong practicability in complex multi-path environment.
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维普
