Abstract:
This paper presents a generalized closed-form beamforming technique that can achieve the maximum degrees of
freedom in compounded multiple-input multiple-output (MIMO)
broadcast channels with mixed classes of multiple-antenna users.
The contribution is first described within the context of a three-cell
network and later extended to the general multicell scenario where
we also show how to determine the conditions required to align the
interference in a subspace that is orthogonal to the one reserved for
the desired signals. This is then followed by an analysis of the impact of antenna correlation for different channel state information
acquisition models. The proposed scheme is examined under both
conventional and large-scale MIMO systems. It will be shown that
the proposed technique enables networks with any combination of
user classes to achieve superior performance even under significant antenna correlation, particularly in the case of the large-scale
MIMO systems.
