Multisector Eigenbeamforming With MMSE Reception in Spatially Correlated Channels

Single-sector eigenbeamforming is effective for obtaining transmit array gain in spatially correlated fading channels while reducing the feedback signaling overhead. However, it may suffer from interference near the sector boundary when applied to the downlink with universal frequency reuse. This interference may not sufficiently be handled by a minimum mean square error (MMSE)-type receiver. To alleviate the interference problem, we consider the use of multisector eigenbeamforming (MEB) in an MMSE receiver, which requires cooperation between adjacent sectors in the same cell. We analyze the performance of the MEB with the use of long-term channel information in terms of the ergodic capacity. Finally, the effectiveness of the proposed MEB near the sector boundary is verified by computer simulation.