Performance Scaling Laws for PD Array-based Receivers in IM/DD Optical Wireless Communication Systems

2026-01-22

AI Summary

This study addresses performance scaling in intensity-modulated/direct-detection optical wireless communication systems employing photodetector (PD) array receivers, with the aim of enhancing signal-to-noise ratio and achievable data rates. Through theoretical modeling, analytical derivation, and numerical simulation—integrating optical reception physics with electrical-domain signal processing—the work reveals a fundamental limitation: performance gains do not scale indefinitely with increasing PD count due to the square-law relationship between optical and electrical power. It is shown that under narrow-beam illumination and high signal-to-noise ratio conditions, PD arrays can yield significant gains, but only when beam shape, electromagnetic mode structure, received optical power, and PD spatial layout are jointly optimized. The study establishes a multi-parameter co-design paradigm, offering practical guidelines and system-level tradeoff insights for high-bandwidth optical wireless receivers.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Distributed Search
• Machine Learning: Scalability of ML Systems

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines
• Security and Privacy: Large-scale security measurements

Abstract

We study the performance scaling laws for electrical-domain combining in photodetector (PD) array-based receivers employing intensity modulation and direct detection, taking into account the inherent square-law relationship between the optical and electrical received powers. The performance of PD array-based systems is compared, in terms of signal-to-noise ratio (SNR) and achievable rate, to that of a reference receiver employing a single PD. Analytical and numerical results show that PD arrays provide performance gains for sufficiently narrow beams and above an SNR threshold. Furthermore, increasing the number of PDs alone does not enhance performance, and joint optimization of beam pattern, transverse electromagnetic mode, received power, and PD positions is necessary. Our model and derived insights provide practical guidelines and highlight the trade-offs for the design of next-generation high-bandwidth PD array receivers.

Problem

• PD array
• IM/DD
• performance scaling laws
• optical wireless communication
• square-law detection

Innovation

• photodetector array
• performance scaling laws
• IM/DD optical wireless communication
• electrical-domain combining
• joint optimization