Comments on Degrees of freedom region for $K$-user interference channel with $M$ antennas

TL;DR

This paper characterizes the degrees of freedom (DoF) region for a $K$-user MIMO interference channel with $M$ antennas at each node, using a simple time-sharing approach, extending beyond the known total DoF.

Contribution

It provides the first explicit characterization of the DoF region for this channel model, which was previously unknown.

Findings

The DoF region is obtained via a simple time-sharing argument.

The maximum total DoF is $MK/2$, but the region details are now known.

The approach simplifies understanding of interference management in MIMO channels.

Abstract

For a $K$-user interference channel with $M$ antenna at each transmitter and each receiver, the maximum total DoF of this channel has been previously determined to be $\max \sum_{k=1}^K d_k = MK/2$. However, the DoF region remains to be unknown. In this short note, through a simple time-sharing argument, we obtain the degrees of freedom (DoF) region of this channel.