Abstract
In this paper, we suggest a new transmission technique for cognitive radio networks. The proposed adaptive underlay/interweave transmission technique is evaluated in the presence and absence of primary interference. The proposed adaptive underlay/interweave transmission technique offers 1-3 dB gains with respect to conventional cognitive radio networks (CRN) using either underlay or interweave. The proposed protocol is extended to CRN with energy harvesting using radio frequency (RF) signals. Our results are valid for any position of primary and secondary transmitter and receiver.