Confidential multiple-input multiple-output optical camera communication aided by a two-dimensional pilot.

Optical camera communication (OCC) has attracted increased attention for its inherent security advantage. However, there still exists the risk of eavesdropping on the broadcasting channel of OCC. To achieve confidential communication, we propose the confidentiality-interference dual light-emitting diode (LED) communication (CIDLC) scheme at the transmitter (TX) and elimination of interference (EI) scheme at the receiver (RX). Meanwhile, interference signals refer to the bit shift of confidential signals. Further, we propose the two-dimensional pilot-aided channel estimation (2D-PACE) scheme to enhance the reliability of multiple-input multiple-output (MIMO) OCC. Experiment results validate the effectiveness of our schemes, which guarantee confidentiality while performing well at a 2 m non-line-of-sight (NLOS) distance. Finally, the communication-illumination integration OCC is constructed via the energy equalization coding (EEC) scheme.

Non-line-of-sight optical camera communication aided by a pilot.

Currently, optical camera communication (OCC), as an emerging network access mode for the fifth-generation (5G), is valued for its advantages over radio frequency (RF). In the long-distance communication scenario, the data rate of line-of-sight (LOS) OCC is restricted. To address this, we propose a pilot-aided demodulation scheme to realize extending the communication distance, while also ensuring the data rate and reliability of the non-line-of-sight (NLOS) OCC. The experiment result validates the effectiveness of the proposed pilot-aided signal layer estimation (PSLE) and extreme value clustering (EVC) scheme, which can perform well against a heterogeneous background with ghost shadows at 2.5 m distance.