Performance analysis of cooperative spatial modulation over different fading channels

Traditional methods are inadequate for the continuing studies that are anticipated to achieve the important goals of the next-generation wireless communication systems, such as ultra-high data rate and enormous bandwidth. Spatial modulation (SM) technique, which is an innovative way of data transmission that was developed by the researchers during these studies, outperforms the conventional methods such in terms of spectral efficiency, energy efficiency and hardware simplicity. Although these advantages of the SM are promising for the next generation technologies, its behavior against the problems, which can be experienced during the practical applications, has not been investigated sufficiently in the literature and the optimal solutions for its utilization with cooperative systems have not been proposed, yet. In this thesis study, the behaviors of SM under the effect of in-phase (I) and quadrature phase (Q) imbalance (IQI), which is one of the hardware impairments that can appear in practice, has been investigated by considering various scenarios. Not only different SM types and various fading channel structures have been considered to bring flexibility to the systems but also channel estimation errors have been taken into account while creating these scenarios. Some additional solutions, such as complexity analysis, are presented for some of the scenarios to better understand the system performance. On the other hand, SM-based techniques have been adapted to cooperative architectures, which are known that they increase the system reliability and quality of service, and the system performance has been investigated. Optimum solutions have been proposed for the SM-based cooperative systems under the effect of IQI and closed form equations have been derived. Specifically, the error performances of the designed systems are solved analytically by optimal maximum likelihood detection (MLD) method, and the obtained results are supported by computer simulations. In consequence of all these studies, it is observed that the effect of IQI needs to be considered seriously while designing next generation technologies, SM is a very efficient method that can be utilized to avoid this error, and cooperative structures considerably improve the system performance of the SM-based systems.