RLS channel estimation with adaptive forgetting factor for DS-CDMA frequency-domain equalization

Yohei Kojima, Hiromichi Tomeba, Kazuaki Takeda, Fumiyuki Adachi

    Research output: Contribution to journalArticlepeer-review

    3 Citations (Scopus)


    Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can increase the downlink bit error rate (BER) performance of DS-CDMA beyond that possible with conventional rake combining in a frequency-selective fading channel. FDE requires accurate channel estimation. Recently, we proposed a pilot-assisted channel estimation (CE) based on the MMSE criterion. Using MSE-CE, the channel estimation accuracy is almost insensitive to the pilot chip sequence, and a good BER performance is achieved. In this paper, we propose a channel estimation scheme using one-tap recursive least square (RLS) algorithm, where the forgetting factor is adapted to the changing channel condition by the least mean square (LMS) algorithm, for DS-CDMA with FDE. We evaluate the BER performance using RLS-CE with adaptive forgetting factor in a frequency-selective fast Rayleigh fading channel by computer simulation.

    Original languageEnglish
    Pages (from-to)1457-1465
    Number of pages9
    JournalIEICE Transactions on Communications
    Issue number5
    Publication statusPublished - 2009 May


    • Channel estimation
    • DS-CDMA
    • Frequency-domain equalization
    • RLS algorithm

    ASJC Scopus subject areas

    • Software
    • Computer Networks and Communications
    • Electrical and Electronic Engineering


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