Method and apparatus for power optimization in wireless systems with large antenna arrays

A wireless base station for communication with a population of one or more terminals, comprising:

• a module configured to transmit, in each of a plurality of iterations, a block of forward-link data from an array of multiple base station antennas to the population of one or more terminals;
• a module configured to update, in each of said iterations, a forward-link power level based on a convergence algorithm for each terminal based on SINR feedback data returned by the population of one or more terminals in response to the forward-link data transmitted in a previous iteration, wherein the forward-link power level substantially converges toward an asymptotic value as a result of the plurality of iterations;
• a module configured to periodically update, during said plurality of iterations, a set of beamforming coefficients based on channel state information (CSI) obtained from reverse-link pilot signals, wherein the CSI is obtained once per a CSI-update period long enough that the CSI obtained in each period is decorrelated from the CSI obtained in a previous period;
• and
• a module configured to precode each said data block, prior to transmission, with most recently updated beamforming coefficients, wherein:
• the transmission module is configured to transmit each said data block at most recently updated forward-link power levels;
• and
• the power-level updating module is configured to update the power levels using local information.