A Method to Optimize the Spreading Code Chip Waveform in Sense of Gabor Bandwidth

Xiaoming Zhang, Zheng Yao, Xin Zhang, Mingquan Lu

Abstract:	Ranging accuracy represented by code tracking error is a major optimization criterion for navigation signals. It has been proved that the lower bound of code tracking error in thermal noise closely links to the Gabor bandwidth of signal [1]. Furthermore, Gabor bandwidth is related to the front-end bandwidth of the receiver and the shape of the navigation signal spectrum. As is known, the signal’s spectrum depends on the chip waveform of the spreading code. Therefore it is of great value to find the optimal spreading code chip waveform to improve the Gabor bandwidth when the bandwidth is limited. In this paper, a generic model for navigation signal is established to optimize the Gabor bandwidth. On the basis of the signal model, a novel method is proposed to find the optimal spreading code chip waveform in a special space spanned by an orthogonal basis of functions in time domain. Multilevel Coded Symbol (MCS) signal, Prolate Spheroidal Wave Functions (PSWF) and Sinusoidal Offset Carrier (SOC) series in a code chip period are selected as basis of functions. Corresponding simulations are carried out to show the performance of some optimized spreading code chip waveform.
Published in:	Proceedings of the 24th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2011) September 20 - 23, 2011 Oregon Convention Center, Portland, Oregon Portland, OR
Pages:	1299 - 1304
Cite this article:	Zhang, Xiaoming, Yao, Zheng, Zhang, Xin, Lu, Mingquan, "A Method to Optimize the Spreading Code Chip Waveform in Sense of Gabor Bandwidth," Proceedings of the 24th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2011), Portland, OR, September 2011, pp. 1299-1304.
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