低轨卫星通导融合信号的高效捕获算法研究OA

Due to the high orbital velocity of low earth orbit(LEO)satellites,the broadcast communication-navigation integrated signals exhibit significant Doppler frequency shifts,which results in a wide Doppler search range and increased difficulty of signal acquisition.Furthermore,the communication-navigation integrated signals are typically transmitted in short-duration bursts,and the duration of the signal is usually only tens of milliseconds,which leads to an extremely limited time window for acquisition,so it is necessary to complete the acquisition search quickly.In response to the characteristics of high dynamics and short bursts of the communication-navigation integrated signals,this study proposes an efficient acquisition optimization architecture based on dual-port RAM.This architecture,integrated partial matched filter(PMF)with fast Fourier transform(FFT),employs a time-division multiplexing data rearrangement scheme to construct the delay stages of the matched filter,so as to achieve high-performance signal acquisition with relatively low hardware resource usage.Results from simulation validation and engineering implementation show that the proposed efficient acquisition algorithm can achieve real-time signal acquisition with a Doppler frequency shift of±40 kHz at a carrier-to-noise density ratio above 46 dB-Hz,so it is an efficient signal acquisition algorithm.