Joint estimation of the channel and I/Q imbalance for two-way relay networks

Saeed Abdallah (), Ahmed I. Salameh (), Mohamed Saad () and Ali A. El-Moursy ()
Additional contact information
Saeed Abdallah: University of Sharjah
Ahmed I. Salameh: University of Sharjah
Mohamed Saad: University of Sharjah
Ali A. El-Moursy: University of Sharjah

Telecommunication Systems: Modelling, Analysis, Design and Management, 2021, vol. 78, issue 3, No 13, 449-462

Abstract: Abstract In this work, we consider amplify-and-forward two-way relay networks operating under the imperfect conditions of in-phase and quadrature-phase (I/Q) imbalance. We propose novel, efficient solutions for the problem of joint channel and I/Q imbalance estimation and the related problem of optimal pilot design. Three different estimation algorithms are developed. The first is the pilot-based maximum-likelihood (ML) estimator. The second is a semi-blind estimator that employs the expectation–maximization (EM) strategy. The third is the semi-blind decision-directed (DD) estimator. As benchmarks on estimation performance, we obtain the analytical expressions for the Cramer–Rao bound (CRB) for pilot-based estimation, and the modified-CRB for semi-blind estimation. In addition to the estimation algorithms, we propose an optimal pilot design that minimizes the mean-squared estimation error. Using simulations, we show that both the pilot-based ML and the semi-blind EM converge to their respective exact CRBs. Importantly, it is shown that both the EM and the DD estimators offer substantially higher estimation accuracy than pilot-based estimation, as well as improved symbol-error-rate (by up to 1.8 dB), which is achieved at a low computational cost.

Keywords: Channel estimation; Cramer–Rao bound; Expectation maximization; I/Q imbalance; Maximum likelihood; Two-way relay network (search for similar items in EconPapers)
Date: 2021
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://link.springer.com/10.1007/s11235-021-00825-7 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:spr:telsys:v:78:y:2021:i:3:d:10.1007_s11235-021-00825-7

Ordering information: This journal article can be ordered from
http://www.springer.com/journal/11235

DOI: 10.1007/s11235-021-00825-7

Access Statistics for this article

Telecommunication Systems: Modelling, Analysis, Design and Management is currently edited by Muhammad Khan

More articles in Telecommunication Systems: Modelling, Analysis, Design and Management from Springer
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().