A low computational design of multiuser MIMO system using large scale array antenna

This paper describes efficient design method of MIMO downlink system adopting large scale array antenna in transmitter side. The proposed approach is suitable when the number of receivers is small compared with the maximum value. First, the large scale antenna is divided into several subarrays, then each of them is designed based on the concept of block diagonalization, and they are combined again as an array of original size. By this operation, the computational load for multiuser design is significantly reduced, which means the proposed method can be applied even in the situation the conventional block diagonalization is computationally impractical. To cope with the uncertainty of receiver weight, two types of procedures are considered, namely, the transmitter first design, and the receiver first transmitter second design approaches. Through computer simulations, it is shown that receiver weight first design method has a better performance when the total stream number is smaller than the maximum value.