Correlated Pointing-Error Analysis for Body-Pointed LED-Based Intersatellite Optical Wireless Links

Abstract

Inter-satellite optical wireless communications (OWC) using light-emitting diodes (LEDs) enable body-pointing CubeSat links without fine acquisition, tracking, and pointing, but they are highly sensitive to relative translation, attitude jitter, and receiver field-of-view (FOV) truncation. This article develops a tractable pointing-error framework for LED-based intersatellite OWC links under small-angle body pointing. The effective transmitter (Tx) off-boresight and receiver incidence angles are marginally Rayleigh distributed, but the shared relative-position residual induces correlated Tx/Receiver (Rx) pointing-loss terms; the resulting channel-gain distribution is obtained from the eigenvalues of the associated Gaussian quadratic form. Finite FOV is incorporated through a mixed discrete–continuous model with a probability mass at zero gain. For an intensity-modulation and direct-detection on–off keying link with a p-i-n receiver and signal-independent noise, we derive analytical outage probability expressions by mapping a target bit error rate to a gain threshold. Monte Carlo results over the statistically resolved plotted range are consistent with the analysis and quantify the impact of LED divergence, Rx FOV, distance, and jitter budgets, providing design guidelines for reliable body-pointing LED intersatellite OWC links.