Multipath Benefits of BOC vs. BPSK Modulated Signals Using On-Air Measurements

Chiawei Lee, Yu-Hsuan Chen, Gabriel Wong, Sherman Lo and Per Enge

Abstract:	Binary Offset Carrier (BOC) modulated signals are currently being used in the Galileo E1 signal and will be used in the future GPS L1C signal. BOC modulation allows for improved multipath performance by narrowing the correlation peak when compared to the BPSK modulation used in the current GPS L1 C/A signal. Multipath effects can be further reduced through the use of composite BOC (CBOC) and time-multiplexed BOC (TMBOC) modulation. This paper presents a methodology and results from collecting and assessing CBOC, BOC(1,1), and Binary Phase Shift Keying (BPSK) multipath performance using a software-defined receiver and a commercial antenna. In contrast to previous work, which focuses primarily on simulated multipath envelopes or tracking algorithms for CBOC/BOC, the methodology in this paper is used to assess and compare multipath performance using collected field measurements. It compares the pseudorange precision of CBOC, BOC(1,1), and BPSK in various scenarios chosen for their expected multipath characteristics. The data collection hardware was mobilized to allow the research team to gather data outside of the lab; in scenarios which more closely mimic the real-world conditions experienced by ground based GNSS users. In total, five scenarios were tested including: 1) open-sky (reference), 2) rooftop, 3) courtyard, 4) urban canyon, and 5) under foliage.
Published in:	Proceedings of the 2013 International Technical Meeting of The Institute of Navigation January 29 - 27, 2013 Catamaran Resort Hotel San Diego, California
Pages:	742 - 751
Cite this article:	Lee, Chiawei, Chen, Yu-Hsuan, Wong, Gabriel, Lo, Sherman, Enge, Per, "Multipath Benefits of BOC vs. BPSK Modulated Signals Using On-Air Measurements," Proceedings of the 2013 International Technical Meeting of The Institute of Navigation, San Diego, California, January 2013, pp. 742-751.
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