Precoding for Point-to-Multipoint Transmission

In this paper we discuss the application of Tomlinson-Harashima-type precoding to point-to-multipoint transmission scenarios. These include the CDMA downlink from a central transmitter (base station) to distributed, decentralized receivers (mobile terminals), as well as transmission from a satellite to multiple receiving earth stations. At the expense of only a very moderate increase in signal processing complexity at the transmitter, the proposed precoding scheme allows the utilization of very low complexity receivers. We show that this type of nonlinear precoding scheme is dual to decision-feedback equalization, applicable in the reverse transmission scenario, i.e., in multipoint-to-point scenarios. The performance of precoding is demonstrated by numerical results.