An Open Problem in DoF-Based Models for Multi-Hop MIMO Networks
Recently, Degree-of-Freedom (DoF) based MIMO models were proposed to characterize Spatial Multiplexing (SM) and Interference Cancellation (IC) behaviors in a multi-hop network. To develop an accurate DoF-based model, the authors need to address the problem on how to determine the node who performs IC for each interference. They show that without an answer to this problem, existing models are either conservative (claim some feasible solutions as infeasible) or opportunistic/incorrect (claim some infeasible solutions as feasible). Thus, they identify an open problem in developing an accurate DoF-based model.