  Large array systems use a massive number of antenna elements and clever
precoder designs to achieve an array gain at the user location. These precoders
require linear front-ends, and more specifically linear power amplifiers (PAs),
to avoid distortion. This reduces the energy efficiency since PAs are most
efficient close to saturation, where they generate most nonlinear distortion.
Moreover, the use of conventional precoders can induce a coherent combining of
distortion at the user locations, degrading the signal quality. In this work,
novel linear precoders, simple to compute and to implement, are proposed that
allow working close to saturation, while cancelling the third-order
nonlinearity of the PA without prior knowledge of the signal statistics and PA
model. Their design consists in saturating a single or a few antennas on
purpose together with an negative gain with respect to all other antennas to
compensate for the overall nonlinear distortion at the user location. The
performance gains of the designs are significant for PAs working close to
saturation, as compared to maximum ratio transmission (MRT) precoding and
perfect per-antenna digital pre-distortion (DPD) compensation.
