Joint Coding Mode and Multi-Path Selection for Video Transmission in D2D-Underlaid Cellular Network with Shared Relays

In this paper, the mode selection (underlay or overlay) for device-to-device (D2D) links at low layers is jointly analyzed with the video coding mode selection and multiple transmission path selection at high layers. For each packet, three video coding modes (I, P, and B) and three transmission paths (cellular link with/without the shared relay and D2D link) are considered to optimize the received video quality expectation. The cross-layer mode selection problem is formulated by maximizing the Quality of Service (QoS) with total energy consumption constrained. Our evaluation shows that the proposed joint mode selection strategy could enhance the perceived QoS with less energy consumption as changing the channel conditions and transmitting power of different paths in a single sector. The coding mode selection is mainly decided by the energy constraint and the path selection mostly depends on the channel conditions.