Wide Field-of-View (FOV) and Bidirectional Unmanned-Aerial-Vehicle (UAV) Based Optical Wireless Communication (OWC) Using Camera

Unmanned-aerial-vehicle (UAV)-assisted optical-wireless-communication (OWC) systems offer several advantages, including data offloading, high flexibility, high mobility, and the ability to temporarily handle unexpected data surges during catastrophic situations. However, some challenges still affect the transmission performance. One of the main challenges in establishing a UAV-based OWC link is to overcome optical misalignment caused by atmospheric turbulence effects and UAV hovering instability. Another challenge is the physical constraints of the transceiver (TRx) optical modules mounted on the UAV, which must be lightweight and compact. In this work, we put forward and present the first demonstration up to the authors’ knowledge a wide field-of-view (FOV) and bidirectional UAV-assisted OWC system using optical-camera-based under-sampled phase shift on-off keying (UPS-OOK) format. The optical-camera-based OWC is known as optical camera communication (OCC). In the proposed system, synchronization can be easily achieved by detecting the “half-on” state, eliminating the need for complicated decoding schemes. Hence, no power-hungry signal processing module is required on the UAV. Optical signal fluctuation at the receiver (Rx) due to atmospheric turbulence effects, UAV hovering and camera tripod swinging can be effectively mitigated through adjacent-pixel aggregation approach in our proposed OCC system. In the proof-of-concept demonstration, bidirectional free-space transmission over 60 m link is successfully demonstrated, achieving data rates of 120 and 60 bit/s in downlink (DL) and uplink (UL) respectively, both fulfilling the forward error correction (FEC) threshold (bit-error-rate, BER = 3.8 × 10−3).