Spatial modulation (SM) is a special multi-antenna transmission technology

where the transmit antenna index is exploited to convey information except for modulation signals.In order to obtain transmit-diversity gains

antenna selection technology is introduced in SM systems to increase its demodulation performance.In antenna selection technology

Euclidean distance antenna selection (EDAS) is widely applied.However

its exhaust-search detection has extremely high complexity

which limits its application.Thus

exploiting the characteristics of modulation symbols and 2-D quantization

two low-complexity and optimal antenna selection algorithms are proposed.The simulation results show that the proposed algorithms reduce the computational complexity meanwhile achieving optimal performance.