Block Diagonalization For Multicell Multiuser MIMO Systems with Other-Cell Interference

We consider the Block Diagonalization (BD) approach assuming multicell multiuser Multiple- Input Multiple-Output (MIMO) systems. For such systems, conventional BD (cBD) eliminates the intra-cell interference but neglects effects related to other cells, i.e., the Other-Cell Interference (OCI). Consequently, an enhanced BD (eBD) was proposed in the literature, which accounts for the presence of the OCI. However, both cBD and eBD suffer from dimensionality restrictions at the Base Station (BS). In this paper, we propose the iterative BD (iBD), which reduces the dimensionality restrictions and accounts for the presence of the OCI as well. It is found that iBD and eBD are equivalent whenever the number of transmitted data streams to a user is equal to the number of its receive antennas. Otherwise, iBD outperforms both eBD and cBD. Detailed simulation results are presented to evaluate the performance of all considered BD approaches.