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