| Popis: |
Due to the research paradigm of the conventional Visible Light Communications (VLC), researchers usually assume that the optical sources follow the Lambertian spatial radiation characteristics. Objectively, this assumption ignores that the potential heterogeneous optical beams based on distinct beams, and the essential exploration for the coverage of the VLC based on the above heterogeneous optical beams. To address the issue, we comprehensively consider the distinct non-Lambertian optical beams characteristics of commercial light emitting diodes, and provide several potential heterogeneous optical beams configuration. Simultaneously, in typical indoor scenario, the coverage characteristics are compared between the conventional Lambertian beam based transmitter configuration and the proposed heterogeneous optical beams configuration. Numerical results show that, compared with the well-known Lambertian transmitter design, the proposed heterogeneous optical beams configuration could provide up to 1.97 dB minimum Signal-to-Noise Ratio (SNR) gain, and modify the SNR fluctuation extent from about 22.75 dB of original design to about 15.33 dB in the heterogeneous configuration. Moreover, via the heterogeneous configuration, the weak coverage proportion with lower than 30 dB SNR, is reduced to about 7.23% from original proportion of about 13.2%. Therefore, to indoor spatial coverage, the effects induced by the heterogeneous optical beams are verified preliminarily. |
