Multiple-antenna OFDM systems

It was highlighted in the general introduction of this book that the application of multiple antennas in transmitter (TX) as well as receiver (RX) of wireless systems provides the possibility to exploit the degrees of freedom provided by the spatial multiple-input multiple-output (MIMO) wireless channel. These systems are generally named after the channel used for the transmission, i.e., MIMO systems. To overcome the frequency selectivity and time dispersion introduced by the wideband multipath propagation channel, the combination of MIMO with the multicarrier technique orthogonal frequency division multiplexing (OFDM) is considered in this book. It was shown in Chapter 1 that this combination, i.e., MIMO OFDM, is also considered as the basis for several next-generation high data rate wireless systems.

In the next chapters different aspects of such multiple-antenna OFDM systems are considered. Since the properties of the wireless channel, and the understanding hereof, are crucial for the design of this kind of systems, this chapter introduces a model for the wideband MIMO wireless channel. This is followed by a review of the basics of MIMO, OFDM and MIMO OFDM. This chapter derives system models for these systems, which will be used throughout this book.