Modulo-Lattice Reduction in Precoding Schemes

Precoding [3] is an attractive strategy when transmitting over channels which suffer from additive noise and an additional interference term which is already known at the transmitter side. For example, Tomlinson-Harashima precoding, initially introduced for intersymbol-interference channels, has been extended to the equalization of MIMO channels such as multiple antenna systems [3]. Key point in this precoding scheme is the use of modulo arithmetics, classically done for oneor two-dimensional symbols. The transmission scheme employing mod-Λ precoding is depicted in Fig. 1. In addition to the channel noise n, an