Physical-layer network coding based interference exploitation strategy for multi-user hierarchical wireless networks

The hierarchical wireless network [1] (HWN) is a promising and popular network architecture which has the capability to support numerous mobile stations (MSs). In the deployment of HWN, the relay nodes (RN) serve as the switching ports for the hub base station (HBS) in the backhaul network (BH) and the MSs in access network (AC) to exchange their own information. However, the co-channel interference (CCI) severely limits the system performance when the incoming signals reach the RNs. Thus, we proposed an effective interference exploitation strategy in which by employing a DS-CDMA scheme, the proposed design can exploit the CCI to provide a diversity benefit, while the physical-layer network coding (PNC) is used to encompass the inter-channel interference (ICI). In this way any form of interference is treated as useful information. It is shown by simulation that the proposed scheme shows advantages in terms of low system complexity, high flexibility, easy deployment and good performance.