Research On Integrated Technology Of High Precision Timing Ranging And Wirless Communication

With the development of communication technology,wireless communication networks not only need to provide data transmission services,but also need to integrate many other functions.Integration of high-precision timing and ranging and wireless communication technology is an important development trend of future wireless networks.The main challenges of integrated technology are two points: one is how to design a waveform that takes into account the timing and ranging performance and communication performance together.The second is how to improve the timing and ranging accuracy of existing waveforms.Therefore,this paper studies the timing,ranging and wireless communication integration technology in the direction of the physical layer to improve the accuracy of timing and ranging and obtain high-speed communication performance.First of all,the paper starts with the two-way timing message exchanges process and combines the clock model to analyze the accuracy error: the timestamp accuracy of the received packet.Therefore,timing synchronization process based on preamble sequence is introduced,and on this basis,an improved plan based on interpolation is given.On-board tests verify the accuracy of the time measurement of the interpolation scheme.At a sampling rate of 40 MHz,interpolation can improve the estimation accuracy of about 5ns,which can improve the performance by about 20 percent.Then,the article gives a physical layer waveform system design for low-speed scenarios.We consider the scenario where the maximum transmit power is limited and combine the peak-to-average ratio(PAPR)of the transmitted signal with the channel capacity.When the peak transmit power of the signal is the same,a signal with a lower peak-to-average ratio can obtain a higher average power at the transmitter,so that a higher signal-to-noise ratio and channel capacity can be obtained at the receiver.Based on the above analysis,we consider the Cramer-Rao lower bound(CRLB)for delay estimation and peak-to-average ratio,and give pulse-shaping fitler and composite binary offset carrier modulation parameters that suitable for the integration of timing,ranging and wireless communication.Finally,the article presents an improved delay and speed estimation scheme for orthogonal time-frequency space(OTFS)modulation technology in high-speed mobile scenarios.Speed estimation is required in high-speed scenarios for high-accuracy timing and ranging.On this basis,the Doppler frequency shift and the channel model are introduced,and the problem is transformed into an estimation of the channel delay and the Doppler frequency shift.Then,we studied a new modulation method:Orthogonal Time Frequency Space modulation.We introduce common channel estimation method for orthogonal time-frequency modulation:embedded pilot method.Aiming at the defect of the algorithm,We first give the solution of fractional Doppler frequency shift in a single path.Then we propose an improved algorithm based on the combination of embedded pilot and multiple signal classification(MUSIC).The simulation results show that Compared with the embedded pilot algorithm,the improved algorithm can improve delay and speed estimation accuracy.Besides,at higher signal-to-noise ratios,the improved algorithm can obtain the same high estimation accuracy as the multiple signal classification algorithm and meanwhile significantly reduce the complexity(about one order of magnitude).Then we analyze the peak-to-average ratio performance of orthogonal time frequency space modulation and compare it with orthogonal frequency division multiplexing.We explain its priority and verify the theory through simulation.