A generalized space shift keying modulation for molecular MIMO systems

Index modulation utilizes spatial dimensions for transmission of information in multiple-input multiple-output (MIMO) molecular communication systems. Molecular space shift keying (MSSK) is an IM-based technique that modulates information in the antenna index and efficiently combats both intersymbol interference and interlink interference in molecular MIMO systems. In this paper, generalized form of the MSSK scheme, that is, generalized MSSK (GMSSK) is proposed which activates a fixed number of antennas for information transmission. The antenna constellation is selected judiciously to minimize the chances of errors in the proposed GMSSK strategy. Design guidelines are provided for the GMSSK antenna constellation for the case of two activated antennas at the transmitter side. Exploiting an additional degree of freedom, the presented GMSSK scheme is shown to achieve reasonably close or better error performance with a smaller antenna array size as compared to the traditional MSSK scheme.