Campus Units

Electrical and Computer Engineering

Document Type

Article

Publication Version

Submitted Manuscript

Publication Date

6-2012

Journal or Book Title

IEEE Transactions on Information Theory

Volume

58

Issue

6

First Page

3766

Last Page

3779

DOI

10.1109/TIT.2012.2185483

Abstract

We study the degrees of freedom (DoF) regions of two-user multiple-input multiple-output Z and full interference channels in this paper. We assume that the receivers always have perfect channel state information. We first derive the DoF region of Z interference channel with channel state information at transmitter (CSIT). For full interference channel without CSIT, the DoF region has been fully characterized recently and it is shown that the previously known outer bound is not achievable. In this paper, we investigate the no-CSIT case further by assuming that one transmitter has the ability of antenna mode switching. We obtain the DoF region as a function of the number of available antenna modes and reveal the incremental gain in DoF that each additional antenna mode can bring. It is shown that, in certain cases, the reconfigurable antennas can increase the DoF. In these cases, the DoF region is maximized when the number of modes is at least equal to the number of receive antennas at the corresponding receiver, in which case the previous outer bound is achieved. In all cases, we propose systematic constructions of the beamforming and nulling matrices for achieving the DoF region. The constructions bear an interesting space-frequency coding interpretation.

Comments

This is a manuscript of an article published as Ke, Lei, and Zhengdao Wang. "Degrees of freedom regions of two-user MIMO Z and full interference channels: The benefit of reconfigurable antennas." IEEE Transactions on Information Theory 58, no. 6 (2012): 3766-3779. DOI: 10.1109/TIT.2012.2185483. Posted with permission.

Rights

© 2012 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.

Copyright Owner

IEEE

Language

en

File Format

application/pdf

Published Version

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