Multi-user detection in optical wireless communication

Optical wireless communication (OWC) has emerged as an attractive and promising solution for supporting high-capacity and high-density networks required by the fifth-generation (5G) communication standard and the Internet of Thing (IoT) system. As a wireless technology, OWC must ensure that multiple users can communicate through the network. To facilitate this, the ability of diverse optical multiple access control (O-MAC) techniques are analyzed in this paper. Combinations of different O-MAC methods that were individually tested in previous work are studied and experimentally validated. Results from testing four methods- Independent Component Analysis (ICA) and non-orthogonal multiple access (NOMA); ICA and signal subtraction; NOMA on one received mixed signal; and NOMA on two received mixed signals-proved successful for free space optical communication (FSOC) in a setup comprised of three users and a dual-path fiber bundle receiver. Users with same data rate and with various data rate were tested. Obtained results showed that received signals were demodulated with high accuracy.