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On The Capacity of Gaussian MIMO Channels Under The Joint Power Constraints

Information Theory 2018-09-05 v1 math.IT

Abstract

The capacity and optimal signaling over a fixed Gaussian MIMO channel are considered under the joint total and per-antenna power constraints (TPC and PAC). While the general case remains an open problem, a closed-form full-rank solution is obtained along with its sufficient and necessary conditions. The conditions for each constraint to be inactive are established. The high and low-SNR regimes are studied. Isotropic signaling is shown to be optimal in the former case while rank-1 signaling (beamforming) is not necessarily optimal in the latter case. Unusual properties of optimal covariance under the joint constraints are pointed out.

Keywords

Cite

@article{arxiv.1809.00056,
  title  = {On The Capacity of Gaussian MIMO Channels Under The Joint Power Constraints},
  author = {Sergey Loyka},
  journal= {arXiv preprint arXiv:1809.00056},
  year   = {2018}
}

Comments

accepted for publication