SPC01-1: Precoding Schemes for the Downlink of a Multiuser Communication System

We consider the downlink of a multiuser communication system with multiple antennas at the transmitter and at each receiver. A new transmission scheme that employs dirty-paper coding (DPC) with partial interference cancellation is proposed. It is shown that given any user ordering the achievable throughput is asymptotically optimal in the high signal-to-noise ratio (SNR) regime and for all values of the SNR it improves over the throughput of the zero-forcing dirty-paper coding (ZFDPC) scheme [1]. Due to its implementation complexity issues, we also consider a low complexity linear transmission scheme. A precoding technique where interference is canceled successively at the base station is proposed. In this case, users treat the partial interference at the receiver as an independent noise, and it is shown that compared to other linear transmission schemes such as the block-diagonalization (BD) and the zero-forcing schemes, the achievable throughput of the proposed precoding scheme is improved for all SNR values.