Memory Resource Integration of GNSS Code Acquisition

C-W. Chen, S-H. Chen, W-L. Mao, H-W. Tsao

Abstract:	The main purpose of GNSS acquisition is to find the code phase and Doppler frequency of visible satellites; however, this process usually has huge operation count, high hardware complexity for correlator and large memory consumption. Many architectures have been proposed about low-complexity correlator design but often have accompany problems such as more control complexity, larger memory consumption or worse signal-to-noise ratio. What we do in this research is to reduce the memory consumption and the operation count in GNSS code acquisition without SNR loss. The proposed code acquisition of our paper is based on the algorithm in paper [1]. In paper [1], the process of code acquisition includes the following three stages: coherent integration stage, correlation stage and incoherent integration stage. Compared with conventional code acquisition, the difference is that the sequence of the first two stages is exchanged, so we call it as exchanged version in this paper. The correlation stage can exchange with coherent integration stage since the operation of these two stages is linear. The operation count is decreased hugely since the correlation stage comes after the finish of coherent integration stage. Based on the exchanged version, the first observation is that the size of coherent integration memory in exchanged version is less than which in the conventional version since the data stored in coherent integration memory is the summation of GNSS signal before correlation in exchanged version, but in the conventional version, the data stored in coherent integration memory is the correlation results which need more store space. The second observation is that the utilization of correlator in exchanged version is lower than the conventional version. Based on our two observations, we propose the memory resource integration (MRI) version in GNSS code acquisition.
Published in:	Proceedings of the 2012 International Technical Meeting of The Institute of Navigation January 30 - 1, 2012 Marriott Newport Beach Hotel & Spa Newport Beach, CA
Pages:	367 - 373
Cite this article:	Chen, C-W., Chen, S-H., Mao, W-L., Tsao, H-W., "Memory Resource Integration of GNSS Code Acquisition," Proceedings of the 2012 International Technical Meeting of The Institute of Navigation, Newport Beach, CA, January 2012, pp. 367-373.
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