Campus Units

Electrical and Computer Engineering

Document Type

Article

Publication Version

Submitted Manuscript

Publication Date

2016

Journal or Book Title

IEEE Transactions on Information Theory

Volume

62

Issue

4

First Page

1931

Last Page

1941

DOI

10.1109/TIT.2016.2529848

Abstract

We first consider a single hop wireless X network with K transmitters and J receivers, all with a single antenna. Each transmitter conveys an independent message for each receiver. The channel is assumed to have constant coefficients. We develop an interference alignment scheme for this setup and derive an achievable degrees of freedom (DoF) region. We show that in some cases, the derived region meets a previous outer bound, and hence, is the (exact) DoF region. For our achievability schemes, we divide each message into streams and use real interference alignment on the streams. Several previous results on the DoF region and total DoF for several special cases can be recovered from our result. Next, we consider a network model, such that each transmitter emits an arbitrary number of messages and each receiver can request an arbitrary subset of all emitted messages. We term this network the X network with multicast. We derive an achievability result for the DoF region of such networks, as well as an outer bound. Our achievability scheme is based on a novel extension of real interference alignment that enables us to achieve more points of the DoF region. This approach allows multiple messages from a single user to be aligned with other users' messages. Finally, we discuss some points on the outer bounds that are not achievable with any of the alignment schemes that we present.

Comments

This article is published as Zamanighomi, Mahdi, and Zhengdao Wang. "Degrees of freedom region of wireless x networks based on real interference alignment." IEEE Transactions on Information Theory 62, no. 4 (2016): 1931-1941. doi: 10.1109/TIT.2016.2529848. Posted with permission.

Rights

© 2016 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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