| Space-frequency coded orthogonal frequency division multiplexing (OFDM) is one of the most promising techniques for future broadband wireless access. Potential applications of space-frequency coded OFDM systems include digital audio/video broadcasting, wireless local area networks such as IEEE 802.11n and HIPERLAN/2, wireless metropolitan area networks such as WiMAX, and future generation broadband mobile wireless systems. To enable portable communication devices (e.g., notebook computers, personal digital assistants, mobile cell phones, etc.) to exchange information at high data rates with prolonged battery lifetime, low complexity receivers with good performance are desired. In this dissertation, we focus on the design of computationally efficient receiver structures for space-frequency coded OFDM systems.;Specifically, we focus on the design of low complexity interference cancellation and channel estimation algorithms for two different space-frequency coded OFDM system configurations. The first of these configurations is space-frequency block coded OFDM (SFBC-OFDM) which yields performance improvement mainly by exploiting spatial diversity. To attain further performance improvement, we propose a concatenated SFBC-OFDM system configuration which exploits both spatial and frequency diversities inherent in multiple-input multiple-output multi-path channels. In addition to designing computationally efficient receivers for the two abovementioned system configurations, we also investigate the performance of the proposed receivers via accurate analytical and simulation methods under various channel conditions. Furthermore, the performances and complexities associated with the designed receiver structures are quantified and compared with those corresponding to the receivers that already exist in the literature. The superior performance-complexity tradeoffs achieved by the proposed receiver structures over the existing ones are demonstrated through these comparisons. |
