Low Computational Signal Acquisition for GNSS Receivers Using a Resampling Strategy and Variable Circular Correlation Time
School of Automation, Beijing Institute of Technology, Beijing 100081, China
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Sensors 2018, 18(2), 678; https://doi.org/10.3390/s18020678
Received: 8 December 2017 / Revised: 8 February 2018 / Accepted: 13 February 2018 / Published: 24 February 2018
(This article belongs to the Special Issue Sensor Signal and Information Processing)
For the objective of essentially decreasing computational complexity and time consumption of signal acquisition, this paper explores a resampling strategy and variable circular correlation time strategy specific to broadband multi-frequency GNSS receivers. In broadband GNSS receivers, the resampling strategy is established to work on conventional acquisition algorithms by resampling the main lobe of received broadband signals with a much lower frequency. Variable circular correlation time is designed to adapt to different signal strength conditions and thereby increase the operation flexibility of GNSS signal acquisition. The acquisition threshold is defined as the ratio of the highest and second highest correlation results in the search space of carrier frequency and code phase. Moreover, computational complexity of signal acquisition is formulated by amounts of multiplication and summation operations in the acquisition process. Comparative experiments and performance analysis are conducted on four sets of real GPS L2C signals with different sampling frequencies. The results indicate that the resampling strategy can effectively decrease computation and time cost by nearly 90–94% with just slight loss of acquisition sensitivity. With circular correlation time varying from 10 ms to 20 ms, the time cost of signal acquisition has increased by about 2.7–5.6% per millisecond, with most satellites acquired successfully.
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Keywords:
signal acquisition; bandpass sampling; circular correlation time; computational complexity; time consumption; GNSS receivers
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MDPI and ACS Style
Zhang, Y.; Wang, M.; Li, Y. Low Computational Signal Acquisition for GNSS Receivers Using a Resampling Strategy and Variable Circular Correlation Time. Sensors 2018, 18, 678.
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