Design and analysis of transmit-beamforming based on limited-rate feedback
IEEE Transactions on Signal Processing
MIMO Transmit Beamforming Under Uniform Elemental Power Constraint
IEEE Transactions on Signal Processing
Bounds on packings of spheres in the Grassmann manifold
IEEE Transactions on Information Theory
On beamforming with finite rate feedback in multiple-antenna systems
IEEE Transactions on Information Theory
Limited feedback unitary precoding for spatial multiplexing systems
IEEE Transactions on Information Theory
| Hi-index | 0.00 |
We propose a numerical method for finding packings of multiple-input and multiple-output (MIMO) semi-unitary precoding matrices in Grassmannian manifolds with different metrics. The proposed expansion-compression algorithm (ECA) is practical, simple and produces efficient packings without the need for a sophisticated initialization. With chordal distance metric, the algorithm tends to converge into a degenerated point constellation, where two points contain identical as well as orthogonal columns and distance between them cannot increase further along geodesic. Therefore, we alternate between max-min and min-max clustering parts of ECA algorithm, where the latter prevents degenerated constellations. With Fubini-Study distance metric, the algorithm converges to best known packings without extra min-max processing.