Space Shift Keying (SSK) Modulation is a novel digital modulation concept suitable for multiple-input multiple-output (MIMO) wireless communication systems. SSK modulation, which is a fundamental component of spatial modulation, inherently exploits fading in wireless communications to provide better performance over conventional amplitude/phase modulation (APM) techniques. In Space Shift Keying (SSK) Modulation, only the antenna indices relay information, and not the symbols themselves.

Space modulation is receiving a growing attention due to the possibility of realizing low–complexity and spectrally–efficient MIMO implementations. The space modulation principle is known in the literature in different forms, such as Information–Guided Channel Hopping (IGCH), Spatial Modulation (SM), and Space Shift Keying (SSK) modulation. Although different from one another, all these transmission technologies share the same fundamental working principle, which makes them different from conventional modulation schemes: they encode part of the information bits into the spatial position of the antenna–array, which plays the role of a constellation diagram (the so–called “spatial–constellation diagram”) for data modulation.

In particular, SSK modulation exploits only the spatial–constellation diagram for data modulation, which results in a very low–complexity modulation concept for MIMO systems.

In SSK modulation, blocks of information bits are mapped into the index of a single transmit–antenna, which is switched on for data transmission while all the other antennas radiate no power. Regardless of the information message to be transmitted, and, thus, the active transmit–antenna, SSK modulation exploits the location–specific property of the wireless channel for data modulation: the messages sent by the transmitter can be decoded at the destination since the receiver sees a different channel impulse response on any transmit–to–receive wireless link.

Space Shift Keying (SSK) Modulation can be a promising low–complexity transmission technology for the next generation MIMO wireless communication systems.