Transceiver design for MSD indoor free-space laser links

In Multi-Spot Diffusing (MSD) configuration, the communication channel can be considered virtually ideal at data rates of hundreds of Mbps. Thus, the main concern is power efficiency. We propose transceiver optical designs that allow for a reconfigurable transmitter output and independent communication channels. Transmitter employs multiple light sources that can be turned on and off independently. This way, optical signal is provided only where it is needed, which optimizes power usage. Receiver utilizes an imaging optical system and segmented photodetector, thus performing direction diversity reception. We show that when maximum ratio combining is employed for the electric signals processing and power efficient modulation schemes like L-PPM are used significant power savings can be obtained.