Increasing Throughput of Dense-Transmitter VLC Networks through Adaptive Distributed MISO

© 2018 IEEE. LED luminaries are densely deployed indoors to provide uniform illumination for better user comfort. To achieve energy efficient uniform illumination, the 'cells' of neighboring LED luminaries are strongly overlapping to increase the cell edge light intensity. Visible Light Communication (VLC) can also benefit from this dense LED infrastructure by exploiting Distributed Multiple-Input-Single-Output (D- MISO). However, overlapping LED cells cause strong interference when multiple transmitters are active. Therefore, in this work, we propose an Adaptive and Distributed MISO (AD-MISO) method to improve the system throughput of a dense-LED-transmitter VLC network that communicates with multiple users. We formulate an optimization problem for deriving the D-MISO transmission strategy adapting the inter- cell interference dynamically, with the goal to increase the system throughput of multiple users. Given the measured link qualities between the distributed transmitters and users, AD-MISO exploits both spatial and time-division multiplexing by dynamically allocating the transmitters to multiple users such that the system throughput is maximized. We also design a heuristic algorithm to reduce the complexity of AD-MISO, and propose a technique to support heterogeneous service requirements. We evaluate the performance of AD-MISO through simulations under various scenarios. Our results demonstrate that AD-MISO outperforms the pure time-division based D-MISO greatly by increasing the average system throughput up to 35.6%, and our heuristic can achieve similar gains while reducing the complexity by 94%.status: publishe