A space shift keying for downlink multi-user transmission with partial CSI in massive MIMO systems

To reduce the burden of channel state information (CSI) acquisition in downlink massive multiple input and multiple output systems, we propose a non-codebook-based precoding scheme for multi-user space shift keying (SSK). The proposed scheme consists of two precoding processes: one precoder to suppress multi-user interference and another to adjust the modulation order for the SSK. The proposed scheme can support downlink multi-user transmission by exploiting the transmit covariance matrix without instantaneous CSI at the transmitter. Moreover, the proposed scheme can achieve better performance than the conventional precoding-aided SSK, regardless of the number of receive antennas.