Title :
Construction of two-dimensional wavelength/time optical orthogonal codes using difference family
Author :
Gu, Fong-Ray ; Wu, Jingshown
Author_Institution :
Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan
Abstract :
A new family of two-dimensional (2-D) wavelength/time optical orthogonal codes (OOCs) for asynchronous optical code division multiple access (OCDMA) systems is proposed. The construction scheme uses the difference family (DF), which is an assemblage of difference sets in the combinatorial theory. It is proven that the proposed codewords satisfy the correlation properties required for the asynchronous OCDMA systems. The code dimension of the proposed codes is more flexible than that of the conventional 2-D codewords. The performance of the system with the proposed codes is analyzed by using the Markov-chain method. Numerical results show that the bit error rate (BER) has a minimal value given the number of simultaneous users. It is also observed that the maximum number of simultaneous users of the system can be achieved by properly choosing both the code weight and cross correlation of the 2-D OOCs.
Keywords :
Markov processes; code division multiple access; codes; combinatorial mathematics; error statistics; optical fibre communication; Markov-chain method; OCDMA; asynchronous optical code division multiple access; bit error rate; combinatorial theory; cross correlation; difference family; optical orthogonal codes; Assembly; Autocorrelation; Bandwidth; Bit error rate; Interference; Multiaccess communication; Optical receivers; Performance analysis; Telecommunication traffic; Two dimensional displays; Bit error rate (BER); Markov chain; code weight; difference family (DF); optical code division multiple access (OCDMA); optical orthogonal codes (OOCs);
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2005.855860
