Spatial Modulation-based Orthogonal Signal Division Multiplexing for Underwater ACOMMS

Orthogonal Signal Division Multiplexing (OSDM) has shown great robustness against multipath and Doppler effects in underwater acoustic channels, while however having a low spectral efficiency. In this work, a novel transmission method, named Spatial Modulation-based OSDM (SM-OSDM), is proposed to improve the spectral efficiency while keeping the Bit Error Rate (BER) low, where multiple transducers are utilized at the transmitter side but only one is active in each time slot. The simulation results prove that the SMOSDM offers higher spectral efficiency than Single-Input SingleOutput (SISO)-OSDM and lower BER compared with MultipleInput Multiple-Output (MIMO)-OSDM.