On the Degrees of Freedom of Interference Alignment for Multicell MIMO Interfering Broadcast Channels

Abstract EN

The interference alignment (IA) is a promising technique to efficiently mitigate interference andto enhance capacity of a wireless network.

This paper proposes an interference alignment scheme fora cellular network with L cells and K users under a multiple-input multiple-output (MIMO) Gaussianinterfering broadcast channel (IFBC) scenario.

The proposed IA scheme aligns intercell interferences(ICI) into a small dimensional subspace through a cooperative receive beamforming and cancelsboth the ICI and interuser interferences (IUI) simultaneously through a transmit beamforming.

Wecharacterize the feasibility condition for the proposed IA to achieve a total number of degrees offreedom (DoF) of LK in terms of the numbers of transmit antennas and receive antennas.

Then wederive the maximum number of DoF achieved by the proposed IA by finding an optimal dimensionof ICI alignment subspace for a given antenna configuration.

The numerical results show that theproposed IA scheme has a better DoF performance than the conventional schemes.