In this paper, physical-layer network coding (PNC) aided bi-directional cooperative relay strategies are proposed for four-node transmitted reference pulse cluster (TRPC) ultrawideband (UWB) systems, which can improve the network throughput and accomplish information exchange within two time slots instead of four. First, we develop a new detector and a link quality indicator (LQI) at the relay side according to the TRPC receiver structure. In view of the definition of LQI, two cooperative relay strategies are proposed, compared with the direct relay combining (RC) which needs three time slots. Simulation results show that the proposed PNC aided two-way relay schemes can improve the network throughput by a factor up to two in comparison to network coding (NC) aided schemes, and achieve better BER performance than the conventional RC.