Linear Degrees of Freedom of MIMO Broadcast Channels with Reconfigurable Antennas in the Absence of CSIT

TL;DR

This paper characterizes the maximum sum linear degrees of freedom in K-user MIMO broadcast and interference channels with reconfigurable antennas and no CSIT, providing a complete understanding of linear coding limits.

Contribution

It provides a complete characterization of the sum linear degrees of freedom for MIMO broadcast and interference channels with reconfigurable antennas without CSIT, including the LDoF region for certain configurations.

Findings

Sum LDoF fully characterized for general antenna configurations.

LDoF region characterized for specific antenna configurations.

Analysis extended to interference channels with reconfigurable antennas.

Abstract

The K-user multiple-input and multiple-output (MIMO) broadcast channel (BC) with no channel state information at the transmitter (CSIT) is considered, where each receiver is assumed to be equipped with reconfigurable antennas capable of choosing a subset of receiving modes from several preset modes. Under general antenna configurations, the sum linear degrees of freedom (LDoF) of the K-user MIMO BC with reconfigurable antennas is completely characterized, which corresponds to the maximum sum DoF achievable by linear coding strategies. The LDoF region is further characterized for a class of antenna configurations. Similar analysis is extended to the K-user MIMO interference channels with reconfigurable antennas and the sum LDoF is characterized for a class of antenna configurations.