Open AccessDesign of Variable Weight code for multimedia service in SAC–OCDMA systems
Author(s) -
Kumawat Soma,
Ravi Kumar Maddila
Publication year - 2018
Publication title -
iet optoelectronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.379
H-Index - 42
eISSN - 1751-8776
pISSN - 1751-8768
DOI - 10.1049/iet-opt.2017.0046
Subject(s) - computer science , code (set theory) , computer network , code division multiple access , variable (mathematics) , service (business) , multimedia , programming language , mathematics , set (abstract data type) , mathematical analysis , economy , economics
Variable weight (VW) codes for spectral amplitude coding–optical code division multiple access system are useful in multimedia applications. VW code algorithm is proposed which is based on enhanced and modified double weight codes. The proposed algorithm can be used for any combination of weights >2. The cross‐correlation among all users is at most 1. This code construction algorithm ensures higher power at receiver for higher‐weight users. Lower‐weight users receive less power compared with higher‐weight users. The difference in received power translates as varying performance, and are useful for multimedia applications. The performance of VW code is analysed using balanced detection (BD) exclusive‐OR operation and direct detection with exclusive‐OR operation. VW code gives comparable or better performance than previously reported code. It is observed that supportable number of users for higher weight, at bit error rate (BER) of 10 −9 (data) are 28, 33 and 35 for random diagonal (RD) code, Khazani‐Syed (KS) code and VW code, respectively, using BD. Supportable number of users for lower weight, at BER of 10 −4 (voice) are 23, 31 and 37 for RD code, KS code and VW code, respectively, using BD.