Spatial Scattering Modulation for Uplink Millimeter-Wave Systems

In this letter, a new spatial scattering modulation (SSM) is proposed for uplink millimeter-wave (mmWave) systems that support a single user terminal (UT). By utilizing the analog and hybrid beamforming with a large antenna array and phase shifters for mmWave communications systems, an architecture, where the UT has a single radio-frequency (RF) chain, whereas the base station has more than one RF chain, is adopted. In this architecture, the proposed SSM modulates some information bits on the spatial directions of scattering clusters in the angular domain, so that a higher spectral efficiency can be achieved with the use of a lower order modulation. For a particular number of scattering clusters and a number of RF chains, a closed-form expression for the upper bound on the bit-error rate (BER) is derived for the proposed SSM. Monte Carlo simulations are also conducted to verify the achievable BER performance.