This paper addresses a time-division multiple-access (TDMA) multiuser multiple-input multiple-output (MIMO) antenna system in if-block Rayleigh flat-fading. Assuming a downlink channel where users are given individual outage probability constraints and that the transmitter knows the statistical information about the channel, we aim to minimize the overall transmit power for achieving the users' probability constraints by jointly optimizing the users' power allocation and time-sharing (i.e., the number of time slots). The proposed scheme composes of a newly derived formula for power minimization of an individual user and solving a convex problem constructed for joint consideration of the power consumptions and the probability constraints. Results demonstrate that the proposed scheme performs nearly the same as the global optimum with inappreciable difference.