A centralized power allocation algorithm for TDD CDMA system with smart antenna in a multi-cellular environment

In TDD CDMA systems, uplink and downlink work at the same frequency, which causes interference between them. The interference in uplink and downlink connection is analyzed respectively within a time slot. Adaptive beamforming is used in uplink receiver beamforming. Beam-steering method is used to achieve downlink transmission beamforming for complexity in downlink. From the beamforming gain and path gain between transmitter and receiver, a normalized gain matrix is constructed. With this matrix we propose an optimum power allocation method that satisfies all users´ SIR requirements at the minimum transmission power. The power allocation algorithm provides an estimate of the optimum performance of all power control schemes