OFFH-CDMA Merged M-Sequence/Hyperbolic Code for Two Weights One Length WDM System

Abstract

In this paper, we propose an extension of two dimensions (2D) code cardinality for slightly same performance (BER). The code is developed for optical code division multiple access (OCDMA) system, it is generated by: hyperbolic code for the Time Spreading and merged M-sequences for the Frequency-Hopping. In this work, we consider the Optical Fast Frequency Hopping technique OFFH-CDMA as an access technique. For the families codes we, apply the constraint of cross-correlation which is equal to one in order to decrease the Multiple Access Interference (MAI). The frequency spacing is selected according to WDM standardization. Optical delay lines and Fiber-Bragg gratings (FBG) are the main elements constituting the encoder/decoder utilized to generate/decode the code words. With the proposed code, we increase the cardinality of our system toP(P-1)2 users instead of P2 users in comparison with Prime code for the same transmission rate (the same code length). Furthermore, with two code weights, two qualities of services (QoS) are proposed and tested rather than one.