A Generalized Dimming Control Scheme for Visible Light Communications

A novel dimming control scheme, termed as generalized (GDC), is proposed for visible light communication (VLC) systems. The basic idea of GDC to exploit adaptively time, spatial and signal domain resources enhancing performance under practical illumination constraints. In particular, satisfy the constraints, an incremental algorithm index mapping first achieve target optical power uniform illumination. Next, having optimal activation pattern investigated improve bit-error rate (BER) VLC. BER analyzed using union bound technique. Based on analytical bound, scheme minimum criterion (GDC-MBER) obtained by exhaustively searching all conditional pairwise error probabilities. However, since GDC-MBER requires high search complexity, two low-complexity schemes maximum free distance (GDC-MFD) are proposed. GDC-MFD GDC-MFD1, derived a lower Rayleigh-Ritz theorem. second GDC-MFD2, reduce further computation exploiting time-invariance characteristics VLC channel. Simulation numerical results show that GDC-MBER, GDC-MFD1 GDC-MFD2 have similar performance, they can more than 3 dB SNR gains compared with conventional 10 -4 level 50%.