Error probability upper bound for perfect sequences implemented with super-structured fibre Bragg gratings

• Published in: IET signal processing Vol. 8; no. 4; pp. 421 - 428
• Main Authors: Pereira, João S, da Silva, Henrique J.A
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 01.06.2014; Institution of Engineering and Technology; The Institution of Engineering & Technology
• Subjects: Applied sciences; bit error rate; Bragg gratings; code division multiple access; code division multiplexing; Coders; codes; Coding, codes; coherent optical code‐division multiple‐access systems; Design engineering; Encoders; error probability upper bound; error statistics; Exact sciences and technology; Fibre; Information, signal and communications theory; OCDMA codes; OCDMA sequences; OCDMA systems; optical decoder technology; optical encoder technology; optical fibre communication; optical fibres; perfect sequence encoder; perfect sequences; Permissible error; power contrast ratios; Reflection; Signal and communications theory; SSFBG code set; SSFBG encoders; SSFBG power reflection model; super‐structured fibre Bragg gratings; Telecommunications and information theory; Upper bounds; OCDMA codes; codes; optical fibres; SSFBG code set; optical fibre communication; OCDMA sequences; code division multiple access; bit error rate; error probability upper bound; super-structured fibre Bragg gratings; Bragg gratings; optical decoder technology; power contrast ratios; OCDMA systems; SSFBG encoders; optical encoder technology; SSFBG power reflection model; code division multiplexing; perfect sequence encoder; coherent optical code-division multiple-access systems; perfect sequences; error statistics; Error probability; M-sequences; Bit error rate; Optical telecommunication; Coding circuit; Wireless telecommunication; Bragg grating; Grating in fiber; Implementation; Angular measurement; Upper bound; Codec; Code division multiple access; Low-power electronics; Simulator; Optical fiber
• ISSN: 1751-9675; 1751-9683; 1751-9683
• DOI: 10.1049/iet-spr.2012.0384

The success of coherent optical code-division multiple-access (OCDMA) systems is strongly dependent on the optical encoder/decoder technology and on the selection of the correct OCDMA codes/sequences. For this reason, in this study, the authors present a method to implement perfect sequences with Super-Structured Fibre Bragg Gratings (SSFBGs). A new SSFBG power reflection model has been found. They have also derived a property that explains why the SSFBGs should use codes derived from m-sequences. Usually, OCDMA researchers try many different codes into SSFBGs in order to select the SSFBG encoders that result in lower error probability. In the authors work, they show that a SSFBG can be considered to be a perfect sequence encoder. For this reason, the codes written into the SSFBGs should be selected based on their new property. This property permits to design and select quickly the correct codes with low power contrast ratios. In addition, a new error probability upper bound, which is a function of the code family and of its power contrast ratio is also presented. With this new bound, it is not necessary to use an optical simulator to estimate the maximum bit error rate of an OCDMA system, if some power contrast ratios of the selected SSFBG code set are known.