Date Added: Jun 2009
Precoding problem in Multiple-Input Multiple-Output (MIMO) ad hoc networks is addressed in this paper. Firstly, the authors consider the problem of maximizing the system mutual information under a power constraint. In this paper, they give a brief overview of the nonlinear optimization methods, and systematically they compare their performances. Then, they propose a fast and distributed algorithm based on the quasi-Newton methods to give a lower bound of the system capacity of MIMO ad hoc networks. Their proposed algorithm solves the maximization problem while diminishing the amount of information in the feedback links needed in the cooperative optimization. Secondly, they propose a different problem formulation, which consists in minimizing the total transmit power under a quality of signal constraint.