Optimizing interference as a source of signal energy with non-linear precoding

Exploiting interference as a useful resource will be one of the main innovations in 5G communications. In this paper, we explore how to handle the interference to reduce the total transmit power of the Tomlinson-Harashima precoder (THP). We show that the energy efficiency can be improved by adaptively scaling the constellation symbols so that they are better aligned with the interfering signals to be canceled. The theoretical and simulation results of this paper prove that the proposed technique is not only able to preserve the average performance of the conventional THP, but it can also increase its power efficiency by a factor of 2 in the considered scenarios.