Coverage Optimization With Beamsteering-Based Indoor Optical Wireless Communications

International audience ; Optical wireless communication (OWC) is now seen as a serious complement to radio frequency solutions, as the latter may soon face a spectrum crunch. OWC systems, however, usually rely on cells generated by fixed access points, so that they often experience a strong quality of service degradation because of frequent handover and inter-cell interference. To overcome these problems, steerable optical antennas may be used at both the infrastructure and user levels. Although such beamsteering solutions have already been explored experimentally, there seems to be no thorough comparison of the performance of such a system, especially in terms of coverage, compared to conventional solutions based on fixed antennas. This paper thus aims to provide such a comparison by simulating three scenarios ('with beamsteering', 'without beamsteering', and with 'manual orientation'), for each of which the bit error rate of a multiband carrierless amplitude phase modulation signal received by a user moving across a 20× 20 m receiving plane at 0.85 m from the floor is estimated. The parameters of this source, its directivity and emission optical power, in particular, are carefully chosen to meet photobiological regulations, and their influence on the coverage is also studied. The results obtained show that beamsteering still enables, in the worst case, a threefold increase in coverage compared to scenarios where it is not or partially used.