Coherence Multiplex System Topologies

Abstract

Coherence multiplexing is a potentially inexpensive form of optical code-division multiple access, which is particularly suitable for short-range applications with moderate bandwidth requirements, such as access networks, LANs, or interconnects. Various topologies are known for constructing an optical transmission system in which several channels are coherence-multiplexed in one optical fiber. In this paper, the parallel array, the intrinsic reference ladder (IRL), and the discontinuous series system topologies will be further considered and compared with respect to code orthogonality requirements, theoretical performance, and some practical implementation aspects. A modification to the IRL system is proposed, resulting in a significant improvement in the theoretical performance.Index Terms-Coherence multiplexing (CM), noise analysis, optical code-division multiple access (OCDMA), optical communication, optical network topologies.

Coherence-Multiplexed Optical RF Feeder Networks

“…CM is a rather unknown optical code division multiple access technique, although it has existed for almost 30 years [4]- [18]. It is based on a channel generation technique called coherence modulation, which was introduced by Delisle and Cielo [4].…”

“…Later on Goedgebuer and Hamel introduced the parallel array, in which each coherence modulator has its own light source [8], [10], [13], [14]. In this paper, we will only consider the parallel array, as it provides most flexibility with respect to transmitter location [17], [18]. A parallel array topology with N transmitters and N receivers is shown in Fig.…”

“…Polarization will not be an issue in the case where integrated MZIs are used for modulation and demodulation, but there might still be a phase offset due to small differences between T Tx and T Rx (for example, due to fabrication inaccuracies, temperature drift, or aging). Several solutions are known in curing this problem (for example, phase synchronization techniques using a feedback loop, or phase diversity [17], [18]).…”

“…In this paper, an optical RF feeder technology is proposed, based on an optical code division multiplexing technique, 0733-8724/$25.00 © 2007 IEEE which is known as coherence multiplexing (CM) [4]- [18]. Because of its potentially simple implementation, CM is an interesting candidate to distinguish between the RAPs.…”

“…Because of its potentially simple implementation, CM is an interesting candidate to distinguish between the RAPs. Moreover, subcarrier multiplexing (SCM) could be used on top of CM [11], [12], [15], [18] (for example, to support multiple MTs through the same RAP or support multicarrier modulation formats).…”