Multi-antenna communication systems with signal space diversity

In this Ph.D. thesis, I studied multiple antenna systems that incorporate signal space diversity (SSD) from a broad perspective. The combination of SSD with multiple antenna systems is shown to be a highly rewarding concept that can provide a reliable and high data rate communication with minimal complexity and cost. The results presented here are very promising for potential future work and system design ideas. The contributions of the thesis cover the journal and conference paper studies that I have done throughout my Ph.D. education. The first chapter is the analysis and field programmable gate array (FPGA) implementation of SSD zero-forcing beamforming with different coordinate interleaving (CI) techniques. The results show that SSD can enhance the error performance of a system significantly and spatial and time CI techniques have various benefits and drawbacks. The performance of zero-forcing multiple-input multiple-output (MIMO) systems with SSD under transmit antenna correlation is also analyzed. It is shown that transmit antenna correlation affects the performance of MIMO SSD systems in a negative way, however different correlation types are less detrimental than others. The second chapter is improving physical layer security in Alamouti orthogonal frequency division multiplexing (OFDM) systems with subcarrier CI. The results show that SSD, when used with subcarrier CI, can be very beneficial to improve the physical layer security of a communication network. Enhancement of the physical layer security of Alamouti OFDM systems is studied under both Rayleigh and Nakagami-m fading channel models. Finally, the third chapter is about the performance of minimum mean-squared error (MMSE) beamforming with time and spatial CI. The results exhibit that SSD technique that is capable of working with different CI strategies can lead up to a huge error performance improvement in MMSE beamforming systems.