Joint resource allocation for wireless energy harvesting based on DF relaying

Abstract

In this paper, a spectrum sharing protocol of cognitive radio (CR) based on joint resource allocation is proposed. The problem of spectrum access for one-way relaying $$ CR $$ networks using decode-and-forward (DF) relaying protocols is investigated. Specifically, in the first phase, the primary transmitter ($$ PT $$ ) sends its own signal to primary receiver ($$ PR $$ ) and cognitive transmitter ($$ CT $$ ). Then, $$ CT $$ divides the received signal into two portions, which are used to decode information and harvest energy, respectively. In the second phase, the accessed bandwidth of $$ CT $$ is divided into two parts. One of the bandwidth is used to forward $$ PT^{'} s $$ signal to $$ PR $$ with the harvested energy. $$ CT $$ can use the other of bandwidth to send $$ CT^{'} s $$ signal to the cognitive receiver ($$ CR $$ ) by using its own energy. The main object is to maximize cognitive system transmission rate by jointly optimizing the power splitting ratio and bandwidth allocation while satisfying the constraint of primary transmission rate.