Publications

Time-Division-Multiplexing Tertiary Offset Carrier Modulation for GNSS
Year 2022
Month
Journal 2022 / Journal of Positioning, Navigation, and Timing vol. 11, no. 3, pp. 147-156
Author Sangjae Cho, Tae Seon Kim, Seung-Hyun Kong*
In this paper, we propose Time-Division-Multiplexing Tertiary Offset Carrier (TDMTOC), a novel GNSS modulation based
on Tertiary Offset Carrier (TOC) modulation. The TDMTOC modulation multiplexes two three-level signals (i.e., -1, 0, and
1) while crossing over time, and is a type of TOC modulation designed specifically for signal multiplexing. The proposed
modulation generates TDMTOC subcarriers of two different phases by simply combining two Binary Offset Carrier (BOC)
subcarriers by addition or subtraction. TDMTOC has better correlation and spectral properties than conventional BPSK, BOC,
and MBOC modulation techniques, and has good power and spectral efficiency since it can multiplex signals without power
loss similar to time division multiplexing. To prove this, we introduce the multiplexing process of TDMTOC, and compare
TDMTOC with Binary Phase Shift Keying (BPSK), BOC, Composite BOC (CBOC), and Time Multiplexed BOC (TMBOC) that
are currently serviced in GNSS by simulations of various aspects. Through the simulation results, we prove that TDMTOC has
better correlation property than modulations currently used in GNSS, less intersystem interference due to its wide spectrum
property, and robustness in multipath and noise channel environments.