ABSTRACT
Future wireless networks will have to deal with a substantial increase of data transmission due to a number of emerging applications that include machine-to-machine communications and video streaming [1]-[4]. This very large amount of data exchange is expected to continue and rise in the next decade or so, presenting a very significant challenge to designers of fifth-generation (5G) wireless communications systems [4]. Amongst the main problems are how to make the best use of the available spectrum and how to increase the energy efficiency in the transmission and reception of each information unit. 5G communications will have to rely on technologies that can offer a major increase in transmission capacity as measured in bits/Hz/area but do not require increased spectrum bandwidth or energy consumption.
