A Novel Weak Signal Acquisition Scheme for Assisted GPS

Il Heung Choi, Sang Hyun Park, Deuk Jae Cho, Sang Jun Yun, Young Baek Kim and Sang Jeong Lee

Abstract:	For RF sensitivity enhancement, the previous assisted GPS acquisition scheme adopts not only the coherent integration technique but also the non-coherent integration technique since the long coherent integration time increases the number of frequency search cells. But the non-coherent integration technique causes the squaring loss, which is a dominant factor among the acquisition losses of assisted GPS dealing with weak GPS signals. This paper proposes an efficient weak signal acquisition scheme for assisted GPS. In this paper, it is explained that the proposed scheme reduces the squaring loss using a modified non-coherent integration technique and that the number of search cells of the proposed scheme is much smaller than that of the previous scheme. Furthermore, it is shown that RF sensitivity of the proposed scheme, in spite of the absence of the sensitivity assistance information, is the same as that of the previous scheme using the sensitivity assistance information. Finally, from the real-time experiment, it can be seen that RF sensitivity of -153dBm is obtained without sensitivity assistance information, and that the mean acquisition time is reduced to 12.5% or 25% of the previous scheme.
Published in:	Proceedings of the 15th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 2002) September 24 - 27, 2002 Oregon Convention Center Portland, OR
Pages:	177 - 183
Cite this article:	Choi, Il Heung, Park, Sang Hyun, Cho, Deuk Jae, Yun, Sang Jun, Kim, Young Baek, Lee, Sang Jeong, "A Novel Weak Signal Acquisition Scheme for Assisted GPS," Proceedings of the 15th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 2002), Portland, OR, September 2002, pp. 177-183.
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