Buffering Instantly Decodable Network Coding for a Heterogenous Cellular Network With Dual Interfaces

Compared with the original instantly decodable network coding (IDNC), buffering IDNC (B-IDNC) can exploit non-instantly decodable packets (NIDPs) containing two unreceiving packets for subsequent network decoding. In this article, we employ B-IDNC in a fully connected D2D networks (FC-D2D) or a partially connected D2D networks (PC-D2D) aided HetNet, where the devices may simultaneously receive two IDNC packets, one from the cellular interface and the other from the device-to-device (D2D) interface. We establish the dual interface B-IDNC graph which can indicate all feasible coding opportunities, conflict-free transmissions, and instant decoding opportunities by exploiting buffered NIDPs. By employing the dual interface B-IDNC graph, a dual interface B-IDNC decoding scheme is developed, in which the IDNC packet which is instantly decodable is preferentially employed to perform network decoding, so as to increase the instant decoding opportunities of the other IDNC packet and the buffered NIDPs. According to the dual interface B-IDNC graph and the dual interface B-IDNC decoding scheme, a heuristic approach named as dual interface maximum decoding clique based maximum weight vertex (D-MDC-MWV) search is proposed to search the transmitting devices and the IDNC packets sent via the dual interfaces. Simulation results verify the effectiveness of the proposed schemes over the existing network coding schemes.