On the Secure Degrees of Freedom of the K-user MAC and 2-user Interference Channels

TL;DR

This paper analyzes the secure degrees of freedom in multi-user MIMO channels with eavesdroppers, providing bounds and achievable schemes for the K-user MAC and 2-user interference channels.

Contribution

It derives the sum SDoF for the 2-user MIMO interference channel and an upper bound for the K-user MAC, with a proposed scheme approaching the bound.

Findings

Sum SDoF of the 2-user MIMO interference channel is characterized.

An upper bound on the sum SDoF of the K-user MAC is established.

Achievable schemes partially meet the upper bound for the K-user MAC.

Abstract

We investigate the secure degrees of freedom (SDoF) of the K-user MIMO multiple access (MAC) and the two user MIMO interference channel. An unknown number of eavesdroppers are trying to decode the messages sent by the transmitters. Each eavesdropper is equipped with a number of antennas less than or equal to a known value NE. The legitimate transmitters and receivers are assumed to have global channel knowledge. We present the sum SDoF of the two user MIMO interference channel. We derive an upperbound on the sum SDoF of the K-user MAC channel and present an achievable scheme that partially meets the derived upperbound.