  Device-to-device (D2D) communication in cellular networks allows direct
transmission between two cellular devices with local communication needs. Due
to the increasing number of autonomous heterogeneous devices in future mobile
networks, an efficient resource allocation scheme is required to maximize
network throughput and achieve higher spectral efficiency. In this paper,
performance of network-integrated D2D communication under channel uncertainties
is investigated where D2D traffic is carried through relay nodes. Considering a
multi-user and multi-relay network, we propose a robust distributed solution
for resource allocation with a view to maximizing network sum-rate when the
interference from other relay nodes and the link gains are uncertain. An
optimization problem is formulated for allocating radio resources at the relays
to maximize end-to-end rate as well as satisfy the quality-of-service (QoS)
requirements for cellular and D2D user equipments under total power constraint.
Each of the uncertain parameters is modeled by a bounded distance between its
estimated and bounded values. We show that the robust problem is convex and a
gradient-aided dual decomposition algorithm is applied to allocate radio
resources in a distributed manner. Finally, to reduce the cost of robustness
defined as the reduction of achievable sum-rate, we utilize the \textit{chance
constraint approach} to achieve a trade-off between robustness and optimality.
The numerical results show that there is a distance threshold beyond which
relay-aided D2D communication significantly improves network performance when
compared to direct communication between D2D peers.
