Abstract
Synchronous Code Division Multiple Access (CDMA) systems possess the advantages of efficient use of the spectral band width, resistance to co-channel interference and adaptability to variable traffic patterns. These advantages result from the usage of orthogonal spreading codes. The popularly used binary (2-level) spreading codes are Walsh, Gold, and Kasami codes. This paper proposes new multilevel (ML) orthogonal spreading codes constructed using ternary and quaternary Gray and Inverse Gray codes for multi-user Direct Sequence Code Division Multiple Access systems. The methodology explained in this paper allows to construct r-level 2n-length user codes. Multilevel spreading codes discussed in this paper are nonzero mean, varying power codes. An attempt is made to analyze these multilevel user codes through auto- and cross-correlation properties and bit error rate. Bit error rate performance of the proposed codes over Gaussian channel and their comparison with those of Walsh and Gold codes is presented in this paper. The proposed codes are found to be more suitable than the existing binary spreading codes.KeywordsGeneralized gray codesInverse gray codesMultilevel spreading codesAuto- and cross-correlation metricsDS-CDMA communicationAWGN channel
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
