Secret-Key Agreement for Security in Multi-Emitter Visible Light Communication Systems.

This letter examines secret key agreement for physical layer security in multiple-input single-output (MISO) visible light communications (VLC) systems. Upper and lower bounds are presented for the single-input single-output VLC secret-key capacities, followed by the analysis of an MISO VLC secret-key transmission strategy. A two-stage numerical approach based on fractional programming is presented for the construction of a secret-key MISO transmit beamforming vector. Numerical evaluations are then presented to validate the analysis and illustrate the secret-key rates achievable in VLC systems.