The tendency towards more mobility and flexibility favours wireless networks for future broadband services, especially in local area and residential networks. Two major challenges in developing such high data-rate wireless networks are the channel distortion caused by multipath propagation and the limitations on bandwidth usage. In this book, novel transmission techniques are proposed that achieve multi-path mitigation, through orthogonal frequency-domain processing, in combination with a high bandwidth efficiency, through space division multiple access (SDMA). By exploiting the parallelism in the data-model and the frequency-selectivity of the propagation channel, high-performance non-linear detection algorithms with modest complexity requirements are obtained. In addition to discussing these core detection algorithms, this book pays special attention to the real-world problems encountered when integrating these into a complete system. Most notably, an optimal multi-user channel estimator and a combined pre- and post-synchronization approach are presented. Furthermore, complexity reduction is a recurring theme throughout the book.