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

A space-time optimal power schedule for multiple distributed multiple-input multiple-output (MIMO) links without the knowledge of the instantaneous channel state information 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. For MIMO links with correlated channels, the corresponding space-time optimal power sch...

• Type: Journal
• Year: 2008
• Where: TSP
• Authors: Yue Rong, Yingbo Hua, Ananthram Swami, A. Lee Swindlehurst
• Keywords: Optimal Power Schedule, Power Schedule, Space-time Optimal Power, TSP 2008