PT  - JOURNAL ARTICLE
AU  - Wang, Xiang
AU  - Cui, Xiaowei
AU  - Liu, Gang
AU  - Wei,, Kefan
AU  - Lu, Mingquan
TI  - Signal Quality Monitoring Based on Chip Domain Observables: Theory, Design, and Implementation
AID  - 10.33012/navi.543
DP  - 2022 Dec 21
TA  - NAVIGATION: Journal of the Institute of Navigation
PG  - navi.543
VI  - 69
IP  - 4
4099  - https://navi.ion.org/content/69/4/navi.543.short
4100  - https://navi.ion.org/content/69/4/navi.543.full
SO  - NAVIGATION2022 Dec 21; 69
AB  - Signal quality monitoring (SQM) is a technique utilized by satellite- and ground-based augmentation systems (SBAS/GBAS) to detect potential hazardous deformations in signals and better protect integrity for safety-critical users. The next generation of SBASs will incorporate dual-frequency multi-constellation (DFMC) techniques, for which SQM is particularly important since signal deformations might be the largest source of uncertainty in ranging error after first-order ionospheric delays are eliminated. However, the performance bounds of the traditional multi-correlator-based SQM technique face some challenges because of the raised requirement on detection sensitivity by dual-frequency ionosphere-free measurements and multiple modulation modes of civilian signals from multi-constellation techniques. To mitigate the challenges and improve overall performance, SQM based on chip domain observables (CDOs) is emerging, but has not yet been systematically studied. We propose a design methodology for CDO-based SQM, consisting of derivations and corresponding massive simulations. Correctness and effectiveness are assessed to confirm the methodology, and a simplification process by checking the sensitivity of CDOs is demonstrated in terms of implementation.