  This paper considers symbol-level precoding (SLP) for multiuser
multiple-input single-output (MISO) downlink. SLP is a nonlinear precoding
scheme that utilizes symbol constellation structures. It has been shown that
SLP can outperform the popular linear beamforming scheme. In this work we
reveal a hidden connection between SLP and linear beamforming. We show that
under an energy minimization design, SLP is equivalent to a zero-forcing (ZF)
beamforming scheme with perturbations on symbols. This identity gives new
insights and they are discussed in the paper. As a side contribution, this work
also develops a symbol error probability (SEP)-constrained SLP design
formulation under quadrature amplitude modulation (QAM) constellations.
