Detector Design and ABEP Analysis for Spatial Scattering Shift Keying in mmWave Systems

To address millimeter-wave (mmWave) path loss, this paper proposes spatial scattering shift keying (SSSK), a modulation scheme encoding data bits onto the indices of selected channel scatterers, suitable for systems with large arrays, a single transmitter RF chain, and multiple receiver RF chains. We introduce the SSSK system model and analyze three detectors: low-complexity greedy, serial maximum likelihood (ML), and joint-processing parallel ML. Complexity analysis confirms that the greedy detector is the simplest, while Parallel ML is the most demanding. Analytical and simulation results for average bit error probability (ABEP) show that parallel ML achieves the best performance by leveraging multi-chain information, significantly outperforming the others. SSSK demonstrates viability against conventional modulations like amplitude phase modulation, offering competitive performance, particularly at higher data rates and high signal-to-noise ratios, effectively utilizing spatial diversity.