A method and apparatus are provided that optimizes a transmitted
user-specific signal. In one embodiment, the invention includes receiving
signals from a remote radio, deriving estimates of receive channels
corresponding to the received signals using the received signals,
deriving a model of an expected transmit channel to the remote radio
based on the receive channel estimates, deriving a set of transmit
parameters to be applied to an array of transmit antennas to transmit a
signal to the remote radio by optimizing a transmit power criteria using
the model of the expected transmit channel and constraints on the
estimated quality of a signal transmitted over the expected transmit
channel, and transmitting to the remote radio by applying the derived set
of transmit parameters to the transmit antenna array.