Fast Acquisition Scheme of the Spread Spectrum Signals for Satellite Communications

Abstract

A four-channel parallel acquisition scheme combining partial matched filters and fast Fourier transforms (PMF-FFT) is proposed for the fast acquisition of the spread spectrum signals in satellite communication terminals installed into the offshore buoys with the high-dynamic movement, which is used tofinish data communication missions between the buoys and the satellite. Compared with traditional code phase FFT scheme, the new scheme reduces the maximum acquisition time to 26.5% and the maximum computation amount to 46.9%. It also improves about 4 times in the frequency resolution and 1.6 dB in the receiving sensitivity at the expense of computation complexity compared to PMF-FFT scheme. The parallel PMF-FFT scheme greatly reduces scallop loss, thus ensuring acquisition sensitivity. The parallel PMF-FFT scheme within the satellite communication terminal can ensure the fast and stable tracking of satellite signal by the violently moving antenna within 20 ms under level-4 sea state.