Interleaved Resource Mapping for Autonomous Device-to-Device Discovery in Public Safety LTE

Abstract

Device-to-device (D2D) discovery is an important function for public safety long term evolution (PS-LTE) to detect user equipment (UE) located in proximity. When many UEs are gathered at a disaster site or an incident command post, in-band emission (IBE) of discovery signals can cause significant interference resulting in discovery errors. In order to reduce the effect of IBE, a radio resource mapping method is proposed for autonomous D2D discovery in a PS-LTE system configured to repeatedly transmit discovery signals over different subframes. The proposed method interleaves discovery resources so that retransmission on resources with a certain frequency gap follows transmission on adjacent resources. Simulation results revealed that the proposed method takes 10% less time to detect UEs than a conventional method does.