In this work we aim to solve the multiuser MIMO downlink beamforming problem. The transmitter is a multiantenna base-station broadcasting to users. Each user may have multiple antennas at the receiver. A solution to the joint transmit-receive beamforming and power allocation under SINR constraints in the downlink of multiuser MIMO systems is proposed. The beamforming filter is a maximum SINR filter which exploits the intra-group cooperation. Taking advantage of the uplink-downlink duality property, the proposed algorithm iteratively compute the transmit-receive beamforming filters and the power allocation matrix.