An adaptive precoder and power allocation algorithm in MIMO system

A joint linear precoding and power allocation algorithm based on users´ QoS is proposed for the downlink of multiuser MIMO systems. This algorithm will improve the channel capacity of the multiuser MIMO system and guarantee different user´s QoS requirement at the same time. The complex problem is simplified and decomposed into three separate steps. First, transmit precoding is computed based on block diagonalization. Second, power matched with least rate requirement each user is allocated. Last, remained power is divided for all over the users in method named filling water. The simulation result shows that it will not only cancel CCI, but also but also meet the users´service requirement compared with the other schemes at the cost of little capacity lost.