International Conference on Information and Knowledge Technology

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Spatial On–Off Keying Modulation with Mirror-Array Optical IRSs for Indoor Machine-to-Machine Visible Light Communication

Authors :

Babak Sadeghi¹ Seyed Mohammad Sajad Sadough²

1- shahid beheshti university 2- shahid beheshti university

Keywords :

Visible Light Communication،intelligent Reflecting Surface،machine-to-machine

Abstract :

This paper presents a comprehensive study of On–Off Keying (OOK) modulation realized through a mirror-array Intelligent Reflecting Surface (IRS) for indoor Machine-to-Machine (M2M) Visible Light Communication (VLC) systems. In contrast to conventional VLC architectures where the light-emitting diode (LED) performs signal modulation, the proposed scheme employs a constant, unmodulated LED optical source, while the IRS encodes information by switching the orientation of its mirror elements. Each mirror cell acts as a controllable reflection unit that directs light toward a designated photodetector (PD) in the ON state and scatters it away in the OFF state, effectively performing spatial OOK modulation. A complete analytical model is developed to describe the optical power propagation, geometric channel gain, and noise behavior under additive white Gaussian noise (AWGN) conditions. The derived expressions for signal-to-noise ratio (SNR) and bit error rate (BER) are validated through MATLAB simulations. Results demonstrate that increasing the IRS unit area significantly improves the received optical power and reduces BER, whereas dividing a fixed total mirror area among multiple units lowers the per-link SNR, revealing a key trade-off between reflection efficiency and multi-user scalability. Additional analyses show that higher Lambertian reflection orders enhance spatial directivity, mitigating inter-user interference and enabling denser IRS deployments. These findings confirm the feasibility of mirror-array IRS-based OOK modulation as a low-complexity, energy-efficient solution for next-generation M2M VLC systems, offering a promising pathway toward LED-independent and reconfigurable indoor communication networks.