Two-dimensional optical orthogonal codes for fiber-optic CDMA networks

Several constructions of two-dimensional (2-D) codes have been proposed to overcome the drawbacks of nonlinear effects in large spread sequences of one-dimensional (1-D) unipolar codes in fiber-optic code-division multiple-access (FO-CDMA) networks. Wavelength-time (W/T) encoding of the 2-D codes is practical in FO-CDMA networks. W/T codes reported so far can be classified mainly into two types: 1) hybrid codes, where one type of sequence is crossed with another to improve the cardinality and correlation properties and 2) conversion of 1-D sequences to 2-D codes to reduce the "timelike" property. This paper describes the basic principles of a new family of wavelength/time multiple-pulses-per-row (W/T MPR) codes, for incoherent FO-CDMA networks, which have good cardinality, spectral efficiency, and minimal cross correlation values. In addition, an expression for the upper bound on the cardinality of W/T MPR codes is derived. Another feature of the W/T MPR codes is that the aspect ratio can be varied by a tradeoff between wavelength and temporal lengths. The correlation properties of W/T MPR codes are verified by simulation using Matlab. For given wavelength /spl times/ time dimensions, various W/T codes, whose cardinalities are known, are compared, and it is shown that the W/T MPR family of codes have better cardinality and spectral efficiency than the other W/T codes. Performance analysis of the W/T MPR codes and their limiting cases is carried out for various parameter variations such as the dimensions of wavelength, time, and weight of the code.

[1]  Jawad A. Salehi,et al.  Code division multiple-access techniques in optical fiber networks. I. Fundamental principles , 1989, IEEE Trans. Commun..

[2]  Ivan Andonovic,et al.  Wavelength hopping/time spreading code division multiple access systems , 1994 .

[3]  Desmond P. Taylor,et al.  Noise limits of optical spectral-encoding CDMA systems , 1995 .

[4]  Sung-Mo Kang,et al.  Modeling and simulation of the OETC optical bus , 1995, LEOS '95. IEEE Lasers and Electro-Optics Society 1995 Annual Meeting. 8th Annual Meeting. Conference Proceedings.

[5]  Guu-chang Yang,et al.  Two-dimensional spatial signature patterns , 1996, IEEE Trans. Commun..

[6]  I. Andonovic,et al.  Massive optical LANs using wavelength hopping/time spreading with increased security , 1996, IEEE Photonics Technology Letters.

[7]  I. Andonovic,et al.  Hybrid wavelength hopping/time spreading schemes for use in massive optical networks with increased security , 1996 .

[8]  Li Bin,et al.  One-coincidence sequences with specified distance between adjacent symbols for frequency-hopping multiple access , 1997, IEEE Trans. Commun..

[9]  Sung-Mo Kang,et al.  Computer Modeling and Simulation of the Optoelectronic Technology Consortium (OETC) Optical Bus , 1997, IEEE J. Sel. Areas Commun..

[10]  Desmond P. Taylor,et al.  Performance enhancement of spectral-amplitude-coding optical CDMA using pulse-position modulation , 1998, IEEE Trans. Commun..

[11]  Ananth Selvarajan,et al.  Design of a new family of two-dimensional codes for fiber-optic CDMA networks , 1998 .

[12]  Leslie A. Rusch,et al.  Passive optical fast frequency-hop CDMA communications system , 1999 .

[13]  J.P. Heritage,et al.  Strategies for realizing optical CDMA for dense, high-speed, long span, optical network applications , 2000, Journal of Lightwave Technology.

[14]  J. Bajcsy,et al.  Design and performance of 2-D codes for wavelength-time optical CDMA , 2002, IEEE Photonics Technology Letters.

[15]  V.J. Hernandez,et al.  Optical CDMA (O-CDMA) technology demonstrator (TD) for 2D codes , 2003, The 16th Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2003. LEOS 2003..

[16]  Paul R. Prucnal,et al.  A scalable wavelength-hopping, time-spreading optical-CDMA system , 2003, The 16th Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2003. LEOS 2003..

[17]  Robert M. Gagliardi,et al.  Design and performance analysis of wavelength/time (W/T) matrix codes for optical CDMA , 2003 .