Optical Coding Theory with Prime

2	Optical Coding Schemes

Since the mid-1980s, there have been steady developments in coding techniques and enabling technologies in the field of coding-based optical systems and networks, exemplified by Optical Code-Division Multiple Access (O-CDMA) and multiplexing [1–34]. With the advances in optical hardware tewachnology, the large bandwidth expansion required by optical codes can now be accommodated and multiple-user O-CDMA experimental testbeds operating at 10 Gbits/s have been demonstrated [34–37]. For instance, there are two main categories of optical coding schemes—synchronous and asynchronous—depending on whether synchronization (usually in time or wavelength) is needed among optical codewords. While both kinds of coding schemes ...