Spatial Modulation (SM) is a novel transmission technique for multiple antenna wireless systems, which increases the throughput through a better adaptation to the channel characteristics. In this paper we present a new Multiuser SM technique that uses QAM adaptive modulation and requires feedback about the channel status. The performance of our proposal is studied through this paper, where exact expressions for the system throughput, goodput and Symbol Error Rate (SER) are obtained, which show an excellent behaviour in comparison to other techniques. Extensive simulations are carried out within several scenarios, where the performance is compared to Space Time Block Codes (STBC) transmission.
