Patent ID: 8243848

Claim:
A radio communication apparatus including multiple transmit antennas, the radio communication apparatus for allocating transmit power to the transmit antennas below transmit power limits of the respective transmit antennas or multiple transmit antenna groups, each of the transmit antenna groups consisting of one or more of the multiple transmit antennas, to transmit a radio signal, the apparatus comprising: a modulation unit configured to modulate information signal sequences to transmit to respective users; a precoding weight calculation unit configured to precode the modulated information signal sequences to calculate transmit weight information for the respective users; an initial transmit power setup unit configured to set initial transmit power based on prior information including the calculated transmit weight information or eigenvalue distribution information; an initial barrier parameter setup unit configured to generate an objective function of a user channel capacity for a constrained optimization problem based on the calculated transmit weight information and the set initial transmit power, generate a new objective function by adding a barrier function adjusted with a barrier parameter to the objective function for the constrained optimization problem, use an initial temporary barrier parameter to initiate iteration of an optimization operation for the new objective function, store an output of each step operation in the optimization operation, and set an initial barrier parameter based on comparison between the current output and the previous output; a transmit power calculation unit configured to calculate transmit power to optimize the new objective function in accordance with an interior point method based on the initial transmit power set by the initial transmit power setup unit and the initial barrier parameter set by the initial barrier parameter setup unit; and a transmit unit configured to allocate the calculated transmit power to the respective transmit antennas to transmit the radio signal.