Abstract

In this thesis, we analyze modulation techniques that exploit multiple antennas in wireless communication. We first study the so-called spatial modulation (SM) technique for MIMO channels. Since the original SM detector is based on an ad hoc design, and only functions under some artificial assumptions about the channel, we derive the optimal detector for SM. The new detector performs significantly better than the original ({598} 4 dB gain), and we support our results by deriving a closed form expression for the average bit error probability. As well, we show that SM with the optimal detector achieves better performance gains ({598}1.5 - 3 dB) over popular multiple antenna systems. We then introduce space shift keying (SSK), a new modulation scheme based on the SM concept. SSK exploits fading in multiple input multiple output (MIMO) channels to provide better performance over conventional amplitude/phase modulation (APM) techniques. In SSK, only the antenna indices, and not the symbols themselves, relay information. This absence of symbol information eliminates the transceiver elements necessary for APM transmission and detection (such as coherent detectors). As well, the simplicity involved in modulation reduces detection complexity compared to that of SM, while achieving almost identical performance gains. Throughout the thesis, we illustrate SSK's strength by studying its interaction with the fading channel, and obtain tight upper bounds on bit error probability. To improve performance, adaptive forms of SSK are also presented, including a symbol design technique, and an antenna selection scheme. We also illustrate SSK's performance under channel estimation error, and spatial correlation. Analytical and simulation results show performance gains over APM systems (3 dB at a bit error rate of 10 -5 ), making SSK an interesting candidate for wireless applications. We then present SSK coded modulation (SSK-CM) to integrate coding for practical wireless systems. In particular, we present a bit interleaved CM (BICM) system using iterative decoding. We illustrate SSK-CM capacity improvements over APM, and derive upper bounds on SSK-CM's performance. We also analytically present SSK's coded diversity advantage over APM, where significant performance gains are observed (up to 9 dB), motivating SSK-CM's integration in future wireless standards