This letter proposes a jointly mapped spatial modulation (JM-SM) scheme to break through the constraint on the number of transmit antennas in traditional SM systems. It is realized via jointly mapping the transmit information bits to 3-D constellation points. A 3-D constellation design scheme for a JM-SM is analyzed and established by minimizing the system average bit error probability (ABEP). In addition, the extension of the joint 3-D mapping to generalized spatial modulation is discussed. The simulation results show that the proposed schemes can be adapted to multiple-input multiple-output systems with an arbitrary number of transmit antennas and offer better ABEP performance than those existing schemes.
['Shuaishuai Guo', 'Haixia Zhang', 'Shi Jin', 'Peng Zhang']
Spatial Modulation via 3-D Mapping