Abstract: In order to improve channel capacity performance,a water-filling power control algorithm is presented for Turbo-BLAST systems with perfect or imperfect channel state information.Under the condition of total power constraints,the water-filling principle is used to allocate power for the tran smitted signal based on the channel state information so thatthe channel capacity can be improved.Simulation results show that,compared with equivalent power control,the proposed algorithm is effective to improve the channel capacity no matter whether the channel estimation is perfect or imperfect.