Known Interference Cancellation: Resolving Collisions Due to Repeated Transmissions

Abstract

Reception of duplicate packets by a node in a wireless network is a common occurrence. Reasons for repeated transmissions range from broadcast flooding to multicast streaming to unicast forwarding. These repeated transmissions may also get involved in collisions like other original transmissions. We argue that when one of the colliding packets is previously overheard, its interference can be cancelled to decode the other packet. In other words, when a receiver overhears a packet, it becomes effectively immune to the interference caused by the packet's subsequent transmission. We refer to this as known interference cancellation (KIC). In this paper, we identify the scenarios in which KIC is applicable. We then implement KIC on USRP/GnuRadio testbed to demonstrate its feasibility and conduct QualNet simulations to illustrate its potential performance gain.