A research study submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Engineering and Technology

Research Studies Project Report (M. Eng.) - Asian Institute of Technology, 1995

Intended for optical code-division multiple access (CDMA) applications, the constructions of a new family of 2 11 codes called the 2 11 extended prime code and the (N, 4, 2, 1) 211 code, are presented in this research study. Since the extended prime code is derived from the well-known prime code by pading some more trailing zeros, the algebraic properties of the extended prime code and the constructed t' code, are still preserved, in particular for the cross-correlation function equal to one. This type of 211 codes can be easily generated by using a simple serial coding architecture, and therefore, a fast reconfiguration time for fully tunable encoders I decoders is guaranteed (ZHANG and PICCHI, 1993). The (N, 4, 2, 1) 211 code is constructed based on Hanani's approach which has been investigated to construct an (N, w, 2, I) optical orthogonal code (OOC). Here, we prove that the obtained (N, 4, 2, 1) OOC can be also an 2" code due to its symmetric pulse positions in the code sequences. Moreover, the performances of the constructed codes are analyzed by using a Gaussian approximation for optical multiple-access interference, and the bit error rates (BER) are discussed in terms of the number of pulses, the code length and the number of simultaneous users.