Adaptive Wireless Network Coding in Network MIMO: A New Design for 5G and After
Tong Peng, Yi Wang, Alister Graham Burr, Mohammad Shikh‐Bahaei · arXiv (Cornell University) · 2018
Physical layer network coding (PNC) has been studied to serve wireless network MIMO systems with much lower backhaul load than approaches such as Cloud Radio Access Network (Cloud-RAN) and coordinated multipoint (CoMP). In this paper, we present a design guideline of engineering-applicable PNC to fulfil the request of high user densities in 5G wireless RAN infrastructure. Unlike computer-and-forward and PNC schemes designed for two-way relay channels, the proposed PNC is designed for uplink of network MIMO systems. We show that the proposed design criterion guarantee that 1) the whole system operates over binary system; 2) each access point can choose singular PNC function to overcome all fade states; 3) the destination can unambiguously recover all source messages while the overall backhaul load remains at the lowest level regardless of which digital mapping is used. We develop a two-stage search algorithm to identify the optimum PNC mapping functions with a practical selection approach which greatly reduces the real-time computation complexity is presented with a small performance loss. Numerical results show that the proposed scheme achieves low bit error rate with reduced backhaul load.