From a technical point of view, the recent development and introduction of new mobile communication systems motivates the design of tailored receiver schemes, signal processing designs that exploit the particularities of new scenarios.

This has motivated the introduction of advanced transmit and receive architectures that exploit not only the properties of the received signals in the time domain, but also their structure in the space domain. Systems operating with more than one antenna and taking advantage of the spatial structure of the propagation channel are currently seen as promising ways of improving the available data rates. Diversity in both space and time domains has traditionally been used to combat the degradations from multipath propagation in the communication.

However, recent research in space-time processing suggests that propagation environments with rich multipath scattering, which have always been regarded as the chief obstacle to high data rates in wireless systems, can in fact offer significant increases in available channel capacity.