A Time Series Based Study of Correlation, Channel Power Imbalance and Diversity Gain in Indoor Distributed Antenna Systems at 60 GHz

Lei Zhang, Simon Cotton, Seong Ki Yoo, Hien Ngo, Marta Fernandez, William Scanlon

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    1 Citation (Scopus)
    77 Downloads (Pure)


    In this article, we investigate the potential enhancements in signal reliability which can be achieved using a millimeter-wave distributed antenna system (DAS) within an indoor environment. To achieve this, we measured the signal power simultaneously received at nine ceiling-mounted access point (AP) locations likely to be used in future indoor DAS deployments while a mobile user imitated making a voice call on a hypothetical user equipment. Key metrics, associated with the performance of multiple antenna systems, such as the cross correlation coefficient (CCC) and channel power imbalance (CPI) are determined. It was found that line-of-sight (LOS) and quasi-LOS (QLOS) links with the APs typically led to higher CCC values than the non-LOS (NLOS) cases. Similarly, LOS and QLOS links typically produced higher CPI values between APs than the NLOS case. To enable the reproduction of our results, we have successfully applied autoregressive moving average and autoregressive integrated moving average modeling to the CCC and CPI time series. The performance improvement that can be achieved using a DAS instead of a single AP was evaluated using three commonly deployed diversity combining schemes, namely, selection combining, equal gain combining, and maximal ratio combining along with three AP selection mechanisms, namely, per-sample random AP selection, one-shot AP selection, and per-sample optimal AP selection. Finally, we have provided some useful insight into the influence of differing AP numbers on the diversity gain when considering the aforementioned AP selection methods.

    Original languageEnglish
    Pages (from-to)7782-7794
    Number of pages13
    JournalIEEE Transactions on Antennas and Propagation
    Issue number11
    Early online date4 May 2021
    Publication statusPublished - 1 Nov 2021

    Bibliographical note

    © 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.


    This work was supported in part by the Northern Ireland Department for the Economy as part of the U.S.-Ireland ?Enabling Cellular Networks to Exploit Millimeter-wave Opportunities (NEMOs)? project under Grant USI080. The work of Hien Quoc Ngo was supported by the U.K. Research and Innovation Future Leaders Fellowships under Grant MR/S017666/1.


    • Antenna measurements
    • Antennas
    • Autoregressive integrated moving average (ARIMA) modeling
    • Correlation
    • Diversity methods
    • Diversity reception
    • Power measurement
    • Time measurement
    • autoregressive moving average (ARMA) modeling
    • channel measurement
    • channel power imbalance
    • distributed antenna system
    • diversity gain
    • millimeter wave
    • time series analysis

    ASJC Scopus subject areas

    • Electrical and Electronic Engineering


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