Performance analysis of a De-correlated Modified Code Tracking Loop for synchronous DS-CDMA system under multiuser environment

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)1991-1999
Journal / PublicationIEICE Transactions on Communications
VolumeE92-B
Issue number6
Publication statusPublished - Jun 2009

Abstract

This paper presents the performance analysis of a De-correlated Modified Code Tracking Loop (D-MCTL) for synchronous direct-sequence code-division multiple-access (DS-CDMA) systems under multiuser environment. Previous studies have shown that the imbalance of multiple access interference (MAI) in the time lead and time lag portions of the signal causes tracking bias or instability problem in the traditional correlating tracking loop like delay lock loop (DLL) or modified code tracking loop (MCTL). In this paper, we exploit the de-correlating technique to combat the MAI at the on-time code position of the MCTL. Unlike applying the same technique to DLL which requires an extensive search algorithm to compensate the noise imbalance which may introduce small tracking bias under low signal-to-noise ratio (SNR), the proposed D-MCTL has much lower computational complexity and exhibits zero tracking bias for the whole range of SNR, regardless of the number of interfering users. Furthermore, performance analysis and simulations based on Gold codes show that the proposed scheme has better mean square tracking error, mean-time-to-lose-lock and near-far resistance than the other tracking schemes, including traditional DLL (T-DLL), traditional MCTL (T-MCTL) and modified de-correlated DLL (MD-DLL). Copyright © 2009 The Institute of Electronics, Information and Communication Engineers.

Research Area(s)

  • Code tracking, DS-CDMA, Multiple access interference (MAI), Synchronization

Citation Format(s)

Performance analysis of a De-correlated Modified Code Tracking Loop for synchronous DS-CDMA system under multiuser environment. / Wu, Ya-Ting; Wong, Wai-Ki; Leung, Shu-Hung; Zhu, Yue-Sheng.

In: IEICE Transactions on Communications, Vol. E92-B, No. 6, 06.2009, p. 1991-1999.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review