Accession Number:

ADA499975

Title:

Space-Time Power Schedule for Distributed MIMO Links Without Instantaneous Channel State Information at the Transmitting Nodes

Descriptive Note:

Journal article

Corporate Author:

CALIFORNIA UNIV RIVERSIDE DEPT OF ELECTRICAL ENGINEERING

Report Date:

2008-02-01

Pagination or Media Count:

17.0

Abstract:

A space-time optimal power schedule for multiple distributed multiple-input multiple-output MIMO links without the knowledge of the instantaneous channel state information CSI at the transmitting nodes is proposed. A readily computable expression for the ergodic sum capacity of the MIMO links is derived. Based on this expression, which is a non-convex function of power allocation vectors, a projected gradient algorithm is developed to optimize the power allocation. For a symmetric set of MIMO links with independent identically distributed channels, it is observed that the space-time optimal power schedule reduces to a uniform isotropic power schedule when nominal interference is low, or to an orthogonal isotropic power schedule when nominal interference is high. Furthermore, the transition region between the latter two schedules is seen to be very sharp in terms of nominal interference-to-noise ratio INR. For MIMO links with correlated channels, the corresponding space-time optimal power schedule is developed based on the knowledge of the channel correlation matrices. It is shown that the channel correlation has a great impact on the ergodic capacity and the optimality of different power scheduling approaches.

Subject Categories:

  • Radio Communications
  • Cybernetics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE