  Enabling technologies for 5G and future wireless communication have attracted
the interest of industry and research communities. One of such technologies is
Device-to-Device (D2D) communication which exploits user proximity to offer
spectral efficiency, energy efficiency and increased throughput. Data
offloading, public safety communication, context aware communication and
content sharing are some of the use cases for D2D communication. D2D
communication can be direct or through a relay depending on the nature of the
channel in between the D2D devices. Apart from the problem of interference, a
key challenge of relay aided D2D communication is appropriately assigning
relays to a D2D pair while maintaining the QoS requirement of the cellular
users. In this article, relay assisted D2D communication is reviewed and
research issues are highlighted. We also propose matching theory with
incomplete information for relay allocation considering uncertainties which the
mobility of the relay introduces to the set up.
