UNDERLAYING INBAND D2D
Early works on D2D in cellular networks propose to reuse
cellular spectrum for D2D communications. To date, the
majority of available literature is also dedicated to inband
D2D, especially D2D communications underlaying cellular
networks. In this section, we review the papers that employ
underlaying D2D to improve the performance of cellular
networks, in terms of spectrum efficiency, energy efficiency,
cellular coverage, and other performance targets.