Effect of Network Coding and Multi-packet Reception on Point-to-Multi-point Broadcast Networks

Abstract

This paper addresses throughput and delay gains resulting from network coding (NC) used to complement multi-packet reception (MPR) in a single-relay multi-user wireless network in saturated and non-saturated traffic conditions. The cross-layer analytical framework is presented in analyzing the performance of the encode-and-forward (EF) relaying wireless networks, where employed at the physical layer under the conditions of unsaturated traffic and finite-length queue at the data link layer. Considering the characteristics of EF relaying protocol at the physical layer, first a model of a two-hop EF relaying wireless channel is proposed as an equivalent extended multi-dimensional Markovian state transition model in queuing analysis. We show that the initial transmissions and the back-filling process can be greatly sped up through a combination of NC and MPR. We provided closed-form expressions for two-hop unbalanced bidirectional traffic cases both with and without NC even if the buffers on nodes are unsaturated. The analytical results are mainly derived by solving queuing systems for the buffer behavior at the relay node. The model has been evaluated through simulations and in comparison with the existing analytical model. Simulation results show good agreement with the analytical results.