Spatial T-H Precoding for Packet Data Systems with Scheduling

This paper combines spatial Tomlinson-Harashima (TH) precoding with packet scheduling at the transmitter to improve the system-level performance of packet data systems. Under the assumptions of instantaneous and perfect channel state information (CSI) at the transmitter and independent and identically distributed (i.i.d.) user channels with flat fading, the spatially equalized and decoupled multiuser channels are shown to be independently faded with distinct orders of diversity. The potential power gain obtained by multiuser scheduling indicates that at medium to high SNR, the average total system throughput can be greatly improved with high spatial multiplexing as compared to a single-antenna system. Keywords-multiple antennas; spatial multiplexing; dirty paper coding; precoding; scheduling