Optimal Power Allocation of Relay Sensor Node Capable of Energy Harvesting in Cooperative Cognitive Radio Network.
A cooperative cognitive radio scheme exploiting primary signals for energy harvesting is proposed. The relay sensor node denoted as the secondary transmitter (ST) harvests energy from the primary signal transmitted from the primary transmitter, and then uses it to transmit power superposed codes of the secrecy signal of the secondary network (SN) and of the primary signal of the primary network (PN). The harvested energy is split into two parts according to a power splitting ratio, one for decoding the primary signal and the other for charging the battery. In power superposition coding, the amount of fractional power allocated to the primary signal is determined by another power allocation parameter (e.g., the power sharing coefficient). Our main concern is to investigate the impact of the two power parameters on the performances of the PN and the SN. Analytical or mathematical expressions of the outage probabilities of the PN and the SN are derived in terms of the power parameters, location of the ST, channel gain, and other system related parameters. A jointly optimal power splitting ratio and power sharing coefficient for achieving target outage probabilities of the PN and the SN, are found using these expressions and validated by simulations.
Faculty of Electrical and Electronics Engineering, Ho Chi Minh City University of Technology and Education, Ho Chi Minh City 70000, Vietnam. sonpndtvt@hcmute.edu.vn.
Pham Ngoc
PN
Son
Cho Chun Shik Graduate School of Green Transportation, KAIST-Korea Advanced Institute of Science & Technology, Daejeon 34141, Korea. dshar@kaist.ac.kr.
Dongsoo
D
Har
Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Korea. nicho@snu.ac.kr.
Nam Ik
NI
Cho
Department of Electrical and Electronic Engineering, University of Ulsan, Ulsan 44610, Korea. hkong@ulsan.ac.kr.
Hyung Yun
HY
Kong
cooperative communication; energy harvesting; optimal power allocation; relay sensor; superposition coding