TY  - JOUR
T1  - Design of Unambiguous Correlation Function for OFDM-BOC(8:4:4,2) Signal
AU  - Yoo, Seungsoo 
AU  - Kim, Sun Yong 
JO  - The Journal of Korean Institute of Communications and Information Sciences
PY  - 2024
DA  - 2024/1/1
DO  - 10.7840/kics.2024.49.8.1039
KW  - Radio Navigation Satellite System (RNSS)
KW  - Low Earth Orbit - Position
KW  - Navigation
KW  - and Timing (LEO-PNT)
KW  - Orthogonal Frequency Division Multiplexing - Binary Offset Carrier (OFDM-BOC)
KW  - unambiguous correlation function
KW  - Code Tracking Bias
AB  - In this paper, we propose an unambiguous correlation function for OFDM-BOC(8:4:4,2) signals and evaluate the spreading code phase tracking performance through simulation. The orthogonal frequency division multiplexing - binary offset carrier (OFDM-BOC) signal is a signal proposed to implement the low Earth orbit-position, navigation, and timing (LEO-PNT) system. Like the binary offset carrier (BOC) signal, the OFDM-BOC signal has high bandwidth efficiency and accurate spreading code phase tracking performance, but is also capable of broadband modulation. Compared with most traditional BOC signals that only use sine or cosine BOC signals, OFDM-BOC signals can use both sine and cosine BOC signals. The designed unambiguous correlation function for the OFDM-BOC signal is composed of a combination of two basis signals, and the correlation function of the designed signal has only half the width of the main peak of the correlation function of the OFDM-BOC(8:4:4,2) signal. Compared to the correlation function of the OFDM-BOC(8:4:4,2) signal having 12 false-lock points, the correlation function of the designed signal does not have any false-lock point. In a typical multipath signal reception environment, the spreading code tracking bias of the OFDM-BOC(8:4:4,2) signal is about 4.5m, while the proposed scheme is about 3.0m, and the maximum running average of the spreading code tracking bias is about half better than that of the OFDM-BOC(8:4:4,2) signal.