Development of new two dimensional FCC-MDW code with wavelength/time scheme in optical code division multiple access (OCDMA) network systems

Abstract

A massive grown specifically for internet users worldwide encourages the service provider along with the researchers to explore an appropriate telecommunication technology that is beneficial to the users. Uniquely, as compared to other multiple access techniques, Optical Code Division Multiple Access (OCDMA) technique can be utilized in optical access network with full services on demand, such as internet protocol, video on demand, tele-presence and high quality audio. In spite of the robustness of OCDMA, the existence of Multiple Access Interference (MAI) and Phase Induced Intensity Noise (PIIN) in the system affects its performance. In fact, MAI is well known as a key factor of performance deterioration in the OCDMA system. For that reason, in this thesis, an investigation was conducted to explore on signature code that can minimize the MAI and PIIN. Another motivation of this study is to discover a signature code that can accommodate a huge number of simultaneous users which is in line with the recent demands. Consequently, two-dimensional (2-D) Flexible Cross Correlation-Modified Double Weight (FCC-MDW) code with Wavelength/Time (W/T) scheme is proposed and demonstrated. Basically, the construction of 2-D FCC-MDW code is formed by merging of two one-dimensional (1-D) OCDMA code known as 1-D FCC and 1-D MDW codes. The development of the code begins by assigning 1-D MDW code as a wavelength encoding pattern and 1-D FCC code sequences as timespreading patterns. Furthermore, in order to mitigate MAI, the encoder and decoder of new 2-D FCC-MDW is designed based on double balanced detection. This thesis provides mathematical and simulation analysis in order to investigate the performance new 2-D FCC-MDW. The combination of wavelength domain and time domain leads to the good property of cross correlation. As a result, mitigation of MAI by the help of double balance detection decoder design, PIIN suppression can be achieved optimally.