NEAR CAPACITY TOMLINSON-HARASHIMA PRECODING WITH UNIFORM STREAM PROPERTIES

摘要

We address the nonlinear transceiver design in a point-to-point MIMO system with Tomlinson-Harashima precoding (THP). By jointly optimizing both transmitter and receiver, capacity can be achieved up to the shaping loss and each stream can be decoded separately. In contrast to linear filtering, THP allows for uniform stream properties rendering bit-loading unnecessary and allows to span an arbitrarily high number of streams for the sake of a reduced cardinality modulation alphabet. Existing work studied either the decision feedback equalizer version with the nonlinearity located at the receiver or the perfect dirty paper precoding where the geometric mean decomposition (GMD) can be applied. We explicitly take the modulo operator into account leading to the fact that the generalized triangular decomposition has to be applied instead of the GMD.