Minimum rates scheduling for MIMO OFDM broadcast channels

In this paper we study the multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) Gaussian broadcast channel (BC). Several fundamental problems are considered: the maximization of a weighted sum of rates and the dual minimization of sum power subject to rate requirements. Further we study the combined problem of weighted rate sum maximization under minimum rate requirements. To show the connections among them, all problems are embedded into an enhanced convex set of rate-power tuples (R, P). This not only gives insights into the structure of the MIMO OFDM BC capacity region, but also motivates algorithms exploiting these properties.