Capacity of the MIMO broadcast channel under realistic propagation conditions

In this paper simulation results of the multiuser MIMO broadcast channel are presented. The MIMO broadcast channel corresponds to the downlink case where the base station sends simultaneously different information to several users in the cell. In contrast to many information theoretical studies, the presented results are based on a realistic MIMO channel model and are therefore a first step towards realistic performance evaluations. The channel model is called multiuser double-directional channel model (MDDCM) and was introduced recently in T. Fugen et al., (2004). It is based on a geometry approach with fixed scatterers. It enables a realistic description of the desired link as well as the spatially-colored interference in a macro-cellular environment. Based on the MDDCM the sum capacity of the MIMO broadcast channel for a varying number of users and varying antenna configurations in an isolated communication cell is presented. To achieve the sum capacity the duality to the MIMO multiple access channels is used