I. Introduction
Recent advances in wavelength-division-multiplexing (WDM) and time-division-multiplexing (TDM) technologies have fueled rapid deployments of optical networking in metro- and wide-area networks. Local-area networks (LANs), on the other hand, have requirements that are not easily met by WDM or TDM technologies. Additional hardware and protocols imposed by WDM and TDM at the distributing nodes unfavorably add to the cost and complexity of the LAN. Optical code-division multiple-access (O-CDMA) allows very flexible access to the large communication bandwidth available in optical networks and a capability of concealing data content. This is possible without relying on complex distribution nodes but with simple reconfiguration of codes at end-user nodes. Many implementations of O-CDMA, using a variety of coding and detection schemes, have been investigated in the last 15 years [1]–[4]. The key challenge in realizing scalable and viable O-CDMA networks lies in overcoming interference from many simultaneous users [multiple-user interference (MUI)].