Network-level cooperation with enhancements based on the physical layer

摘要: Recently, cognitive cooperation has received a great deal of attention, where the relay utilizes periods source silence to enable without consuming extra network resources. In this paper, we investigate more enhanced cooperative techniques on top existing network-layer conventional by exploiting degrees freedom at physical layer. wireless multiple-access channel with two primary users and relay, first study dynamic decode-and-forward scheme in which can also be activated during user's transmission, provide assistance for successful reception destination. Then, an adaptive superposition is proposed allowing node simultaneously serve packets relayed from users, according instantaneous feedback. The schemes are evaluated performance measure stable throughput region.