Avalanche Photodiode-Based Deep Space Optical Uplink Communication in the Presence of Channel Impairments

• Published in: Photonics Vol. 12; no. 6; p. 562
• Main Authors: Guo, Wenjng, Wu, Xiaowei, Yang, Lei
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.06.2025
• Subjects: Accuracy; Approximation; Atmospheric turbulence; Avalanche diodes; avalanche photodiode; Background noise; Communication; Communications systems; Deep space; deep space optical communication; Disability; Discovery and exploration; Efficiency; Field of view; Fluctuations; Ground stations; Monte Carlo method; Monte Carlo simulation; Moon; Noise reduction; Noise tolerance; Optimization; Outer space; Photodiodes; Pulse position modulation; Radiation, Background; Signal processing; Space exploration; symbol error rate; Technology application; uplink channel model; Uplinking; Webb and Gaussian models; United States; New Jersey
• ISSN: 2304-6732; 2304-6732
• DOI: 10.3390/photonics12060562

Optical communication is a critical technology for future deep space exploration, offering substantial advantages in transmission capacity and spectrum utilization. This paper establishes a comprehensive theoretical framework for avalanche photodiode (APD)-based deep space optical uplink communication under combined channel impairments, including atmospheric and coronal turbulence induced beam scintillation, pointing errors, angle-of-arrival (AOA) fluctuations, link attenuation, and background noise. A closed-form analytical channel model unifying these effects is derived and validated through Monte Carlo simulations. Webb and Gaussian approximations are employed to characterize APD output statistics, with theoretical symbol error rate (SER) expressions for pulse position modulation (PPM) derived under diverse impairment scenarios. Numerical results demonstrate that the Webb model achieves higher accuracy by capturing APD gain dynamics, while the Gaussian approximation remains viable when APD gain exceeds a channel fading-dependent gain threshold. Key system parameters such as APD gain and field-of-view (FOV) angle are analyzed. The optimal APD gain significantly influences the achievement of optimal SER performance, and angle of FOV design balances AOA fluctuations tolerance against noise suppression. These findings enable hardware optimization under size, weight, power, and cost (SWaP-C) constraints without compromising performance. Our work provides critical guidelines for designing robust APD-based deep space optical uplink communication systems.