Enabling techniques for asynchronous coherent OCDMA

The coherent OCDMA system could suffer from severe multiple access interference (MAI) and beat noise, which limit the maximum number of active users that can be supported in a network. One effective method to reduce the beat noise as well as the MAI noise is to lower the interference level by adopting ultra-long optical code. Applying optical thresholding technique is also crucial to enable data-rate detection for achieving a practical OCDMA system. In this paper, we review the recent progress in the key enabling techniques for asynchronous coherent OCDMA: the novel encoder/decoders including spatial lightwave phase modulator, micro-ring resonator for spectral phase coding and superstructured FBG (SSFBG) and AWG type encode/decoder for time-spreading coding; optical thresholding techniques with PPLN and nonlinearity in fiber. The FEC has also been applied in OCDMA system recently. With 511-chip SSFBG and SC-based optical thresholder, 10-user, truly-asynchronous gigabit OCDMA transmission has been successfully achieved. Most recently, a record throughput 12×10.71 Gbps truly-asynchronous OCDMA has been demonstrated by using the 16×16 ports AWG-type encoder/decoder and FEC transmit ITU-T G.709 OTN frames.

[1]  Edward H. Sargent,et al.  The role of optical CDMA in access networks , 2002 .

[2]  Naoya Wada,et al.  Demonstration of 12-user, 10.71 Gbps truly asynchronous OCDMA using FEC and a pair of multi-port optical-encoder/decoders , 2005 .

[3]  K. Kitayama.  State of the art of and application OCDMA, OCDM, and OC-label switching , 2004 .

[4]  A. Weiner.  Femtosecond pulse shaping using spatial light modulators , 2000 .

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

[6]  K. Kitayama,et al.  Dispersion-flattened-fiber based optical thresholder for multiple-access-interference suppression in OCDMA system. , 2005, Optics express.

[7]  S. Galli,et al.  Spectrally efficient optical CDMA using coherent phase-frequency coding , 2005, IEEE Photonics Technology Letters.

[8]  J.H. Lee,et al.  Demonstration of a four-channel WDM/OCDMA system using 255-chip 320-Gchip/s quarternary phase coding gratings , 2002, IEEE Photonics Technology Letters.

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

[10]  W. Chujo,et al.  1.6-b/s/Hz 6.4-Tb/s QPSK-OCDM/WDM (4 OCDM x 40 WDM x 40 Gb/s) transmission experiment using optical hard thresholding , 2002, IEEE Photonics Technology Letters.

[11]  P. Petropoulos,et al.  Demonstration of a 64-chip OCDMA system using superstructured fiber gratings and time-gating detection , 2001, IEEE Photonics Technology Letters.

[12]  A. Viterbi.  CDMA: Principles of Spread Spectrum Communication , 1995 .

[13]  Periklis Petropoulos,et al.  A comparative study of the performance of seven- and 63-chip optical code-division multiple-access encoders and decoders based on superstructured fiber Bragg gratings , 2001 .

[14]  Periklis Petropoulos,et al.  A grating-based OCDMA coding-decoding system incorporating a nonlinear optical loop mirror for improved code recognition and noise reduction , 2002 .

[15]  M. Ibsen,et al.  A holey fiber-based nonlinear thresholding device for optical CDMA receiver performance enhancement , 2002, IEEE Photonics Technology Letters.

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

[17]  Andrew M. Weiner,et al.  Nonlinear fibre-optic receiver for ultrashort pulse code division multiple access communications , 1997 .

[19]  David D. Sampson,et al.  Photonic code-division multiple-access communications , 1997 .

[20]  A. Agarwal,et al.  Fully-programmable ring resonator based integrated photonic circuit for phase coherent applications , 2005, OFC/NFOEC Technical Digest. Optical Fiber Communication Conference, 2005..

[21]  G. Cincotti,et al.  200 Gchip/s, 16-label simultaneous multiple-optical encoder/decoder and its application to optical packet switching , 2005, OFC/NFOEC Technical Digest. Optical Fiber Communication Conference, 2005..

[22]  Joseph Y. Hui.  Pattern Code Modulation and Optical Decoding - A Novel Code-Division Multiplexing Technique for Multifiber Networks , 1985, IEEE Journal on Selected Areas in Communications.

[23]  G. Cincotti.  Design of optical full encoders/decoders for code-based photonic routers , 2004, Journal of Lightwave Technology.

[24]  A.M. Weiner,et al.  Four-user, 2.5-Gb/s, spectrally coded OCDMA system demonstration using low-power nonlinear processing , 2004, Journal of Lightwave Technology.

[25]  K. Kitayama,et al.  High reflectivity superstructured FBG for coherent optical code generation and recognition. , 2004, Optics express.

[26]  K. Kitayama,et al.  High-performance optical code generation and recognition by use of a 511-chip, 640-Gchip/s phase-shifted superstructured fiber Bragg grating. , 2005, Optics letters.