Elevation-Dependent Outage of Position-Aided LEO Satellite Beamforming Under GNSS Spoofing
IEEE COMMUNICATIONS LETTERS, ss.1-4, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1109/lcomm.2026.3743112
- Dergi Adı: IEEE COMMUNICATIONS LETTERS
- Derginin Tarandığı İndeksler: Scopus, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest), Aerospace Database, Science Citation Index Expanded (SCI-EXPANDED), Compendex, INSPEC
- Sayfa Sayıları: ss.1-4
- Orta Doğu Teknik Üniversitesi Kuzey Kıbrıs Kampüsü Adresli: Evet
Özet
Position-aided beam steering and Doppler precompensation reduce training and synchronization overhead in low-Earth-orbit (LEO) links, but they also couple the physical layer to the integrity of the reported navigation solution. This letter studies the resulting outage under Global Navigation Satellite System (GNSS) spoofing. The model uses exact three-dimensional spherical geometry for arbitrary horizontal spoofing orientation, an elevation-dependent link budget, and exact finite-N orthogonal frequency-division multiplexing (OFDM) carrier frequency offset (CFO) coefficients. A closed-form conditional outage expression and its high signal-to-noise ratio (SNR) asymptote are derived. The adaptive beamwidth policy is evaluated by averaging outage over an imperfect spoofing-bias estimate rather than assuming perfect attack knowledge. The analysis is validated against 105-trial Monte Carlo simulations with maximum absolute errors of 6.69×10−4 and 1.52×10−3 for the undefended and adaptive designs. Over a uniformly sampled 0–3 km bias sweep, the adaptive design achieves the lowest average outage, 0.1325, compared with 0.2221, 0.1475, and 0.1835 for the undefended, average-optimal fixed, and minimax fixed beams, respectively. Its peak reduction relative to the undefended design is 51.52%. At 3 km, it reduces the required zenith SNR for 10% outage from 25.87 to 20.25 dB, while remaining within 0.20 dB of the minimax fixed beam. Sensitivity analyses over attack orientation, adjacent-beam interference, detector error, missed detections, and shadowed-Rician fading identify the operating conditions under which adaptive widening remains beneficial.