Fast GPU based acquisition with minimum loss and downsampling techniques for weak BeiDou SBAS signals

Abstract

For a receiver of the BeiDou Satellite Based Augmentation System (BDSBAS), the acquisition aims to coarsely estimate the pseudo-code delays and carrier Doppler shifts of the received signals. The use of downsampling techniques to accelerate this acquisition process for weak signals has been an emerging topic. However, the acquisition probabilities of conventional algorithms with downsampling are inadequate and need to be enhanced to prevent excessive false alarms due to degradation of the peak signal-to-noise ratios (PSNRs) during acquisition. To improve signal acquisition performance, we introduce an enhancer function before downsampling to achieve the minimum PSNR loss during acquisition. Then, we use graphic processing unit (GPU) functions to speed up the processing loop, matrix multiplication and fast Fourier transform operations. We thus present a fast GPUbased acquisition method by using minimum loss and downsampling techniques. Our experimental results show the remarkable effectiveness of our method for receiving weak BDSBAS signals as compared to legacy downsampling algorithms. This work seeks not only to solve the current issue of achieving fast acquisition of weak BDSBAS signals but also to inspire creative new ideas that spur further advances in this promising field in the future.