A Dynamic Spot Diffusing Architecture for Indoor Wireless Optical Communications

In this work we introduce a novel high-speed architecture for indoor wireless optical communications termed the dynamic spot diffusing (DSD) architecture. In this configuration the transmitter modulates data onto a spot on the ceiling which moves in a closed path. An imaging receiver acquires data whenever the transmitter spot is in its field-of-view (FOV). We show that this technique is more flexible, has greater multipath immunity, permits higher data rates and has a simpler transmitter than previously defined multi-spot and diffuse architectures. We compare the available channel capacities for a family of spot paths and receiver FOV. Instead of synchronizing to the spot location, rateless erasure correcting codes are applied to approach the capacity of the simulated DSD links. In a 6 × 6 × 3 m room, simulated data rates vary between 12.1 Mbps to 40 Mbps at different positions using a single 100 Mbps transmitter and the designed erasure correction code.