An Adaptive Optimal Mapping Selection Algorithm for PNC Using Variable QAM Modulation

Abstract

Fifth generation (5G) wireless networks will need to serve much higher user densities than existing 4G networks, and will therefore require an enhanced radio access network (RAN) infrastructure. Physical layer network coding (PNC) has been shown to enable such high densities with much lower backhaul load than approaches such as Cloud-RAN and coordinated multipoint (CoMP). In this letter, we present an engineering applicable PNC scheme which allows different cooperating users to use different modulation schemes, according to the relative strength of their channels to a given access point. This is in contrast with compute-and-forward and previous PNC schemes which are designed for two-way relay channel. A two-stage search algorithm to identify the optimum PNC mappings for given channel state information and modulation is proposed in this letter. Numerical results show that the proposed scheme achieves low bit error rate with reduced backhaul load.Index Terms-adaptive PNC, industrial applicable, backhaul load, unambiguous detection.

Implementation of uplink network‐coded modulation for two‐hop networks

“…The SFSs and mappings are included in the Appendix. More details of the PNC design can be found in the work of Peng et al…”