LAST: A Framework to Localize, Access, Schedule, and Transmit in Indoor VLC Systems

The need allowing indoor access to the Internet services requires to reduce the electromagnetic pollution. Recently, the scientific community is looking for alternatives to the use of radio frequency communication, leading to propose and study the new paradigm of visible light communications. In order to present a system implementing transmission and access procedures, we propose a logical stream starting from user localization, so as to decide which LEDs can provide access, thus basically performing a space-division multiple access by scheduling data on the basis of the bits to be transmitted. For this aim, a two-bands access scheme is proposed, and implemented through the use of a separated channel where signaling specifies where, in the wavelength domain, the reception must be operated by the different users. A multiple-input multiple-output scheme is considered for data transmission, in order to increase rate with a reliable error rate performance. Performance is evaluated for what concerns localization and access tasks, so as to show the effectiveness of the proposed scheme. Performance comparison with the recent literature has been also reported.