Hybrid optical network using incoherent Optical Code Division Multiple Access via optical delay lines

Joel Quintana, University of Texas at El Paso


Over the past 20 years there has been extensive research on the application of spread spectrum multiplexing techniques for communications via optical fiber. Optical Code Division Multiplexing (OCDMA) is the technique that has exhibited the most promise as a primary multiplexing vehicle for the transition into all-optical processing of data, and as a supplement to other techniques such as Time Division Multiplexing (TDM) and Wave Division Multiplexing (WDM). OCDMA can be classified into incoherent OCDMA, where coding and detection is done on the basis of optical power, and coherent OCDMA where coding is done on a field amplitude basis. The commercialization of these technologies has been a slow process as interferometic noise (know as beat noise), multiuser access interference (MAI) and optical component cost are the major hurdles.^ This thesis concentrates on the application of incoherent OCDMA on a Fiber to the Home (FTTH) type access network where users receive information from a central terminal that is OCDMA encoded electronically. Only the user with the proper optical decoding stage will be able to discriminate and reconstruct the original information. The decoding is done via passive optical delay lines performing a convolution between the electrical orthogonal optical code (OOC) and the impulse response of the optical delay lines. The result is an autocorrelation peak or a crosscorrelation that provides no outstanding optical intensity peak.^ This document analyzes the proper autocorrelation and crosscorrelation waveforms for 2 users on this “hybrid” OCDMA coding scheme and defines threshold, beat noise mitigation and information reconstruction techniques for further expansion of the network. ^

Subject Area

Engineering, Electronics and Electrical

Recommended Citation

Quintana, Joel, "Hybrid optical network using incoherent Optical Code Division Multiple Access via optical delay lines" (2009). ETD Collection for University of Texas, El Paso. AAI1465268.