Reduced-RF-Chain Aided Soft-Decision Multi-Set Steered Space-Time Shift-Keying for Millimeter-Wave Communications

Soft-decision-aided multi-set steered space-time shift keying intrinsically amalgamated with channel coding is proposed in order to attain near capacity-performance. Multi-set space-time shift keying (MS-STSK) is a multiple-input multiple-output scheme, which combines the concepts of spatial modulation (SM) and STSK for the sake of achieving high data rates and enhanced system integrity. Furthermore, an MS-STSK is combined with orthogonal frequency-division multiplexing (OFDM) as well as single-carrier frequency domain equalization (SC-FDE) and additionally enhanced by analog beamforming in order to support communications at millimeter-wave (mmWave) frequencies. Given that OFDM-based SM systems cannot directly benefit from the reduced number of RF chains of SM due to the spreading effects of the fast-Fourier transform and they suffer from a high peak-to-average power ratio, we opt for employing the SC-based arrangement. The soft-decision-aided detector of the SC-based MS-STSK is combined with recursive systematic convolutional encoding and iterative detection at the receiver side in order to achieve excellent performance within 1.1 dB and 1.4 dB, respectively, from the capacity limit for the soft-decision MS-STSK system and within 1.1 dB from the capacity limit for the SC-FDE-aided soft-decision MS-STSK. We also use extrinsic information transfer charts for analyzing our systems and evaluate their achievable rates.