Trellis ternary line coding scheme for asynchronous optical CDMA systems

Abstract In this paper, we investigate the employment of a ternary line coding technique based on Ungerboeck's trellis-coded method in asynchronous optical CDMA systems. The ternary coding we use is predicated upon the equal-weight orthogonal (EWO) scheme. Each user transmits two mutually orthogonal signature sequences to represent “+1” and “−1”, respectively, and nothing is transmitted for “0”. The receiver employs a maximum-likelihood soft-decoder to select the path with minimum Euclidean distance as the preferred path. This trellis ternary coding scheme applies set partitioning with partially overlapping subsets to increase the free Euclidean distance, which considerably improves system performance. Furthermore, due to line coding technique, such scheme comprises sufficient clock information, and thus benefits for baseband timing extraction (i.e. clock recovery). Numerical results reveal that the proposed trellis ternary coding scheme can significantly reduce the error floor and allow more active users to be accommodated in the network.

[1]  Sherman Karp,et al.  Optical Communications , 1976 .

[2]  Gottfried Ungerboeck,et al.  Channel coding with multilevel/phase signals , 1982, IEEE Trans. Inf. Theory.

[3]  Mark Leeson,et al.  Principles of Lightwave Communications , 1996 .

[4]  John G. Proakis,et al.  Digital Communications , 1983 .

[5]  A. Elrefaie,et al.  Impact of laser linewidth on optical channel spacing requirements for multichannel FSK and ASK systems , 1989, IEEE Photonics Technology Letters.

[6]  Jian-Guo Zhang.  Novel tunable ultra-high-speed optical fiber code-division multiple-access networks for real-time computer communications , 1995, Proceedings IEEE International Conference on Communications ICC '95.

[7]  Andrew J. Viterbi,et al.  Principles of Digital Communication and Coding , 1979 .

[8]  Ranjan Gangopadhyay,et al.  Performance of linecoded optical heterodyne FSK systems with nonuniform laser FM response , 1995 .

[9]  Erdal Panayirci,et al.  New ternary line codes based on trellis structure , 1993, IEEE Trans. Commun..

[10]  Xu Wang,et al.  Analysis of beat noise in coherent and incoherent time-spreading OCDMA , 2004, Journal of Lightwave Technology.

[11]  A.E. Willner,et al.  Experimental and theoretical analysis of the optimum decision threshold for varying numbers of active users in a 2-D time-wavelength asynchronous O-CDMA system , 2005, Journal of Lightwave Technology.

[12]  Abtin Keshavarzian,et al.  Multiple-shift code acquisition of optical orthogonal codes in optical CDMA systems , 2005, IEEE Transactions on Communications.

[13]  Jawad A. Salehi,et al.  Atmospheric optical CDMA communication systems via optical orthogonal codes , 2006, IEEE Transactions on Communications.

[14]  R.F. Ormondroyd,et al.  Dual-threshold sequential detection code synchronization for an optical CDMA network in the presence of multi-user interference , 2000, Journal of Lightwave Technology.

[15]  Edward A. Lee,et al.  Digital communication (2. ed.) , 1994 .

[16]  Paul R. Prucnal,et al.  Spread spectrum fiber-optic local area network using optical processing , 1986 .

[17]  G. David Forney,et al.  Efficient Modulation for Band-Limited Channels , 1984, IEEE J. Sel. Areas Commun..

[18]  Daniel J. Costello,et al.  An algorithm for computing the distance spectrum of trellis codes , 1989, IEEE Journal on Selected Areas in Communications.

[19]  Wing C. Kwong,et al.  Performance comparison of asynchronous and synchronous code-division multiple-access techniques for fiber-optic local area networks , 1991, IEEE Trans. Commun..

[20]  Tomoaki Ohtsuki,et al.  Performance analysis of direct-detection optical asynchronous CDMA systems with double optical hard-limiters , 1997, Proceedings of ICC'97 - International Conference on Communications.

[21]  Alex W. Lam.  Direct-detection APD-based optical CDMA using orthogonal signalings , 1991, [1991 Proceedings] Tenth Annual International Phoenix Conference on Computers and Communications.

[22]  T. Satake,et al.  Demonstration of simultaneous FDM signal switching by polarization-controlled switch for survivable fiber networks , 1992, IEEE Photonics Technology Letters.

[23]  Ryoji Takeyari,et al.  Alternate-mark-inversion optical continuous phase FSK heterodyne transmission using delay-line demodulation , 1991 .

[24]  K. Kitayama,et al.  OCDMA over WDM PON-solution path to gigabit-symmetric FTTH , 2006, Journal of Lightwave Technology.

[25]  Alex W. Lam,et al.  Performance analysis of direct-detection optical CDMA communication systems with avalanche photodiodes , 1992, IEEE Trans. Commun..

[26]  G. Agrawal.  Fiber‐Optic Communication Systems , 2021 .

[27]  G. Picchi,et al.  Tunable prime-code encoder/decoder for all-optical CDMA applications , 1993 .

[28]  Jack K. Wolf,et al.  Trellis Coding for Partial-Response Channels , 1986, IEEE Trans. Commun..

[29]  T.H. Shake,et al.  Security performance of optical CDMA Against eavesdropping , 2005, Journal of Lightwave Technology.

[30]  Leonid G. Kazovsky,et al.  Optical Fiber Communication Systems , 1996 .

[31]  Abtin Keshavarzian,et al.  Optical orthogonal code acquisition in fiber-optic CDMA systems via the simple serial-search method , 2002, IEEE Trans. Commun..

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