基于LEO辅助的北斗B1C高灵敏快速捕获算法

LEO-assisted High-sensitivity and Fast Acquisition Algorithm of BeiDou B1C Signal

关键词:  低轨  捕获  灵敏度  捕获时间

Key words:  Low Earth orbit  Acquisition  Sensitivity  Acquisition time

摘要:

随着低轨(LEO)卫星数量的不断增加，利用LEO星座辅助增强GNSS导航性能已经成为一种新的趋势。针对低信噪比环境下B1C信号难以捕获的问题，提出了一种基于LEO辅助的B1C信号高灵敏快速捕获算法。首先对提升接收机捕获灵敏度进行了分析，对比了相干积分与非相干积分对于信号处理增益的影响，得出在低轨导航增强信号的辅助下采用增加相干积分时间的捕获算法对低信噪比条件下B1C信号的捕获更有效。然后提出了一种基于LEO辅助的B1C高灵敏快速捕获算法，从理论分析和实验仿真两方面，对比验证了在LEO辅助下可以显著提高B1C信号的捕获灵敏度，缩短捕获时间，提高捕获效率。

Abstract:

With the continuous increase in the number of LEO (Low Earth Orbit) satellites, the use of LEO constellations to assist in enhancing GNSS (Global Navigation Satellite System) navigation performance has become a new trend. As it is difficult to capture B1C signals in a low SNR environment, a LEO-assisted highly sensitive and fast acquisition algorithm of Beidou B1C signal is introduced. First, the receiver's acquisition sensitivity enhancement is analyzed, and the influences of coherent integration and non-coherent integration on the signal processing gain are compared, and it is concluded that the acquisition algorithm which increases the coherent integration time with the aid of the LEO navigation enhancement signal is more effective in the capture of B1C signal under the conditions of low signal-to-noise ratio. Then, a LEO-assisted B1C high-sensitivity and fast acquisition algorithm is proposed. Through theoretical analysis and experimental simulation, it is verified that, with the assistance of LEO, the acquisition sensitivity and efficiency of B1C signal can be significantly improved, and the acquisition time can be greatly shortened.