Rethinking the Detectors Design of Spatial Scattering Modulation for mmWave MIMO Systems

Spatial scattering modulation (SSM), an emerging millimeter-wave multiple-input multiple-output (MIMO) modu-lation technique, exploits spatial beam resources to enhance the modulation degree of freedom. However, to address the problem that the detection performance of existing scalar-based maximum likelihood (SML) detector is not optimal and the complexity is too high, this paper develops vector-based maximum likelihood (VML) and low-complexity (LC) detectors for the structural char-acteristics of SSM system receivers, respectively. The complexity of the proposed VML algorithm is slightly higher than that of the traditional SML detection algorithm, while the complexity of the proposed LC detection algorithm is reduced by 50% compared with the traditional SML detection algorithm. Numerical results show that at average bit error probability (ABEP) = 10–<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup>, the signal-to-noise ratio (SNR) required for the VML-based ABEP values is 5.5 dB less than that obtained from SML detection. Moreover, the proposed LC algorithm detection performance also saves SNR of 1 dB over SML detector.