Spatial modulation (SM) is an important multi-antenna transmission technique. By encoding the data with additional spatial information, the spectral efficiency is enhanced without extra bandwidth. By extending the SM concept to the multiple-user in a massive multiple-input multiple-output (MU-M-MIMO) scenario, only one radio frequency (RF) is needed in the transmitter (Tx), which improves the energy efficiency. To further reduce the cost and power consumption, one-bit digitalto-analog converters (DACs) are adopted in the Tx RF chain at the expense of high precoding complexity to compensate the severe performance degradation caused by the nonlinear one-bit quantization distortion. In this paper, a low-complexity precoding scheme based on the forward-backward splitting (FBS) method is presented for the large-scale multi-antenna system with SM and quadrature-phase-shift-keying (QPSK) signaling. Preliminary simulation results show that, comparing to the other one-bit DAC based benchmark methods, the proposed precoder is able to achieve the same (or better) BER at a much lower computational complexity.
