Space modulation techniques (SMTs) have emerged as promising candidates for spectral- and
energy-efficient wireless communication systems since they strike a good balance among error performance,
power efficiency, spectrum efficiency, and receiver complexity. In SMTs, the information is not only
conveyed by the habitual M-ary signal constellations; rather, it is also conveyed by the indices of the transmit
antennas. As such, the indices of the transmit antennas are harnessed in such a manner that enhances the
transmission efficiency compared to the other multiple-input multiple-output (MIMO) opponents. Despite
their exceptional advantages, SMTs suffer from a major drawback, which lies in the logarithmic proportion
between their achievable data rates and the number of transmit antennas. In this regard, the fully-generalised
spatial modulation (F-GSM) and the fully-quadrature spatial modulation (F-QSM) are proposed in this paper
in order to vanquish this controversial drawback. In F-GSM and F-QSM, the transmit antennas used for data
transmission are varied from the state in which only one transmit antenna is activated to the state in which
multiple/all transmit antennas are activated. Therefore, a linear relationship between the achievable data rates
and the number of transmit antennas is acquired. Moreover, a novel mathematical framework for assessing
the average bit error rate (ABER) performance of the different SMTs is delineated. The driven mathematical
framework is considered as the first major attempt to generalize the analytical analysis of different SMTs. In
addition, the receiver’s computational complexity of the proposed schemes is obtained and analysed in terms
of the computational complexity of different SMTs. The simulation results substantiate the validity of the
analytical analysis conducted throughout the paper, as they are very akin to the obtained analytical formulas.