Discrete-phase constant envelope precoding for massive MIMO systems
File(s)
Author(s)
Kazemi, Mohammad
Aghaeinia, Hassan
Duman, Tolga M
Type
Journal Article
Abstract
We consider downlink of a multiuser massive multiple-input multiple-output (MIMO) system and focus on reducing the hardware costs by using a single common power amplifier and separate phase shifters (PSs) for antenna front-ends. In the previous literature, the use of analog PSs in this setup has been considered. Here, we study the use of practical digital PSs, which only support a limited set of discrete phases. Considering the sum of interference powers as a metric, we formulate the corresponding nonlinear discrete optimization problem and solve for the phases to be used during transmission. We devise a low-complexity algorithm, which employs a trellis structure providing suboptimal, but efficient and effective solutions. We demonstrate via examples that the proposed solutions have comparable performance to conventional analog PS-based algorithms. Furthermore, we prove that by utilizing discrete-phase constant envelope precoding, the interference can be made arbitrarily small by increasing the number of antennas. Therefore, the asymptotic gains promised by massive MIMO systems are preserved. We also obtain closed-form expressions for the rate loss due to errors in the phase and amplitude of the PSs, for both low and high SNR regimes.
Date Issued
2017-05-01
Date Acceptance
2017-02-01
Citation
IEEE Transactions on Communications, 2017, 65 (5), pp.2011-2021
ISSN
0090-6778
Publisher
Institute of Electrical and Electronics Engineers
Start Page
2011
End Page
2021
Journal / Book Title
IEEE Transactions on Communications
Volume
65
Issue
5
Copyright Statement
Copyright © 2017 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.
Subjects
Constant envelope precoding
digital phase shifter
discrete optimization
Engineering
Engineering, Electrical & Electronic
massive MIMO
multiuser MIMO
Science & Technology
SEMIDEFINITE RELAXATION
Technology
Telecommunications
WIRELESS
Publication Status
Published
Date Publish Online
2017-02-13