Performance Enhancement of Indoor Cellular Visible Light Communication through Cell Size and Wavelength Reuse Pattern

Abstract

AbstractThe emerging technology of visible light communication (VLC) has become a promising solution for the requirements of wide-bandwidth, high-speed, and infinite-capacity wireless communication networks. A novel design of high-performance multi-user indoor visible light communication (VLC) based on hexagonal-cell arrangement is introduced in the present paper. The wavelength division multiple access (WDMA) is used to enable multiple users to communicate through the network of access point (APs) by assigning a unique wavelength division channel (WDC) to each user. A wavelength reuse scheme is utilized to increase the maximum number of users in the system and to enhance the VLC system capacity. The on–off keying (OOK) is used as the modulation technique for light signaling. The intercell interference (ICI) caused by the wavelength reuse is evaluated and its dependence on the cell radius and the wavelength reuse pattern size is numerically investigated. Both the received power density and the ICI at the location of the moving user are evaluated and the resulting signal-to-ICI ratio (SICIR) is calculated at every point over the indoor area. The VLC system capacity is evaluated and its dependence on the design parameters including the cell radius, the size of the wavelength reuse pattern, and the user data rate is numerically investigated. A design procedure is proposed to minimize the bit-error rate (BER) resulting from the ICI and to maximize the system capacity and the maximum allowable number of users in the system by selecting the optimal radius of the hexagonal cells and the most appropriate size of the frequency reuse pattern. The effect of the data rate per user on the system capacity is numerically investigated. It is shown that a SICR of greater than 21 dB and BER of less than 1 × 10−15 is achieved. Also, a system capacity of more than 4 bps/Hz is achieved by the application of the proposed VLC design optimization procedure.