OM2DNC: Opportunistic Max2-Degree Network Coding for wireless data broadcasting

Abstract

In wireless broadcasting systems, multiple retransmissions are commonly employed to guarantee the correct reception of each packet. The traditional hybrid automatic retransmission request protocol retransmits one packet per slot. Hence, a large amount of retransmissions is required to correctly receive all the packets, which leads to low spectrum efficiency. In this paper, we propose an Opportunistic Max2-Degree Network Coding (OM2DNC) based wireless broadcasting (WBC) protocol. Specifically, to reduce the overall number of retransmissions, lost packets of different user equipments (UEs) are combined by performing Max-Degree network coding (NC) at the access node. Then, NC combined packets are broadcasted by utilizing the Max-Degree based opportunistic retransmission protocol. At each UE, the lost packet can be recovered by using the proposed joint network recursive systematic convolution decoder. Theoretical analyses and simulation results show that the average number of transmissions performance of the proposed OM2DNC based WBC protocol outperforms that of the traditional NC based WBC protocols.