Interference-Aware RZF Precoding for Multicell Downlink Systems

Recently, a structure of an optimal linear precoder for multi cell downlink systems has been described, and many other references have used simplified versions of this precoder to obtain promising performance gains. These gains have been hypothesized to stem from the additional degrees of freedom th...

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Bibliographic Details
Published in:IEEE transactions on signal processing Vol. 63; no. 15; pp. 3959 - 3973
Main Authors: Muller, Axel, Couillet, Romain, Bjornson, Emil, Wagner, Sebastian, Debbah, Merouane
Format: Journal Article
Language:English
Published: IEEE 01.08.2015
Subjects:
Channel estimation
Covariance matrices
Downlink
Electronic mail
Interference
Interference mitigation
Limiting
linear precoding
multicell downlink
multiuser MIMO
random matrix theory
Signal processing algorithms
ISSN:1053-587X, 1941-0476, 1941-0476
Online Access:Get full text
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Summary:Recently, a structure of an optimal linear precoder for multi cell downlink systems has been described, and many other references have used simplified versions of this precoder to obtain promising performance gains. These gains have been hypothesized to stem from the additional degrees of freedom that allow for interference mitigation through interference relegation to orthogonal subspaces. However, no conclusive or rigorous understanding has yet been developed. In this paper, we build on an intuitive interference induction trade-off and the aforementioned preceding structure to propose an interference aware RZF (iaRZF) precoding scheme for multi cell downlink systems, and we analyze its rate performance. Special emphasis is placed on the induced interference mitigation mechanism of iaRZF. For example, we will verify the intuitive expectation that the precoder structure can either completely remove induced inter-cell or intra-cell interference. We state new results from large-scale random matrix theory that make it possible to give more intuitive and insightful explanations of the precoder behavior, also for cases involving imperfect channel state information (CSI). We remark especially that the interference-aware precoder makes use of all available information about interfering channels to improve performance. Even very poor CSI allows for significant sum-rate gains. Our obtained insights are then used to propose heuristic precoder parameters for arbitrary systems, whose effectiveness are shown in more involved system scenarios. Furthermore, calculation and implementation of these parameters does not require explicit inter base station cooperation.
ISSN:1053-587X
1941-0476
1941-0476
DOI:10.1109/TSP.2015.2423262