English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

This paper studies the sum Degrees of Freedom (DoF) of $K$-user {\emasymmetric} MIMO Interference Channel (IC) with square direct link channelmatrices, that is, the $u$-th transmitter and its intended receiver have$M_u\in\mathbb{N}$ antennas each, where $M_u$ need not be the same for all$u\in[1:K]$.  Starting from a $3$-user example, it is shown that existing cooperation-basedouter bounds are insufficient to characterize the DoF. Moreover, it is shownthat two distinct operating regimes exist. With a {\it dominant} user, i.e., auser that has more antennas than the other two users combined, %(say $M_1\geqM_2+M_3$), it is DoF optimal to let that user transmit alone on the IC.Otherwise, it is DoF optimal to {\em decompose} and operate the 3-user MIMO ICas an $(M_1+ M_2+M_3)$-user SISO IC. This indicates that MIMO operations areuseless from a DoF perspective in systems without a dominant user.  The main contribution of the paper is the derivation of a novel outer boundfor the general $K$-user case that is tight in the regime where a dominant useris not present; this is done by generalizing the insights from the 3-userexample to an arbitrary number of users.

The DoF of the Asymmetric MIMO Interference Channel with Square Direct Link Channel Matrices