目前，以空间调制(Spatial Modulation，SM)、广义空间调制(Generalized Spatial Modulation，GSM)为代表的新型MIMO技术，成为4G以及5G的关键技术。空间调制系统在一个符号周期内，发送端只选择部分发送天线发送信号，从而大大提高了频谱效率，是大规模MIMO系统的重大突破。(At present, the new MIMO technology represented by spatial modulation (SM) and generalized spatial modulation (GSM) has become the key technology of 4G and 5g. In a symbol period, the transmitter only selects part of the antenna to transmit the signal, which greatly improves the spectral efficiency. It is a major breakthrough in large-scale MIMO systems.)