Performance of MMSE Beamforming with Time and Spatial Coordinate Interleaving

Abstract

We incorporate minimum mean square error (MMSE) beamforming (BF) schemes utilizing various number of transmit antennas with signal space diversity (SSD). Coordinate interleaving (CI) is performed in the spatial and time domains. The system has no channel state information (CSI) at the transmitter and imperfect CSI is assumed at the receiver in order to study the benefit of SSD under channel estimation errors. A parallel transmission takes place between the transmitter and the receiver, where MMSE BF is performed according to the erroneously estimated CSI. It is demonstrated that by using time or spatial CI, it is possible to highly improve the error performance of a MMSE BF system without the need of extra bandwidth, time slots or significant complexity increment. Different CI strategies used in this work present alternative solutions for different system design criteria in terms of error performance and latency.