| Summary: | 碩士 === 國立中正大學 === 電機工程研究所 === 92 === O-CDMA(Optical Code Division Multiple Access) plays an important role in modern optical-communication system.To provide a flexible solution for asynchronous and high capacity communication. Because optical-fiber has excellent properties to resist the noise from magnetic and electric, and it also can translate information lossless in long distance. In this paper, we introduce and discuss about two dimension coding approach in FBG(Fiber Bragg Grating)-based O-CDMA. The discussion includes devices、coding method、systemic architecture and performance analysis. We also bring up an idea to construct 2D O-CDMA codewords by modifying the Shuffled Walsh-Hadamard method. The MSWH (Modified Shuffled Walsh-Hadamard) method uses modified models to get better correlation property and 3D cube-cutting in three dimensions to product more 2D patterns than original Shuffled Walsh-Hadamard method. Finally, we compare the different coding methods (Modified Shuffled Walsh-Hadamard、Modified Prime-Hop code、M-matrix) according to correlation property, BER(Bit Error Rate), number of devices and bit-rate. In conclusion, we can say that the modified Shuffled Walsh-Hadamard coding method has good corss-correlation property, and higher bit-rate in special condition with a little number of users.
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