Cooperative Spectrum Sharing on SWIPT-Based DF Relay: An Energy-Aware Retransmission Approach

Abstract

In this paper, cooperative cognitive radio networks are considered, in which a primary user (PU) and an off-the-grid secondary user (SU) co-exist by exploiting simultaneous wireless information and power transfer. Based on a two-phase relaying model, adaptive power splitting is performed at the SU for information decoding while collecting the energy remaining in the first phase. The energy harvested is then used to forward the decoded primary signal, with the secondary signal superimposed in the second phase. To enhance the utilization of both the spectrum and energy, an energy-aware retransmission approach is proposed for enabling successful decoding at the SU while collecting a reasonable amount of energy for relaying. The outage probability and throughput are theoretically analyzed for both the PU and the SU. To provide more analytical insights, tight performance upper and lower bounds are obtained in closed forms. Our results demonstrate that a mutually beneficial relationship can be built between the PU and the SU under proper parameter configurations. Furthermore, a performance tradeoff with respect to the number of retransmissions is demonstrated, where additional performance gains can be achieved by the proposed retransmission approach under unfavorable conditions of high rate, low power, and weak channels.INDEX TERMS Cooperative cognitive radio networks, simultaneous wireless information and power transfer, adaptive power splitting, decode-and-forward, energy-aware retransmission.

Energy Efficiency Analysis in Modified GoF Spectrum Sensing-Based AF Relay Cooperative Cognitive Sensor Network with Energy Harvesting

“…Recently, RF EH in CSN has become the object of extensive research [10][11][12][13][14][15][16][17][18]. In [10], a two-phase decoded-andforward (DF) relay model was constructed by employing adaptive PS at the ST node; the outage probability and throughput were analysed.…”

“…Recently, RF EH in CSN has become the object of extensive research [10][11][12][13][14][15][16][17][18]. In [10], a two-phase decoded-andforward (DF) relay model was constructed by employing adaptive PS at the ST node; the outage probability and throughput were analysed. In [11], the ST employed the TS protocol to harvest energy and decode the PT's information; the secondary throughput was maximized by optimizing the energy harvesting time and the ST's relaying power.…”

Hybrid Automatic Repeat Request (HARQ) in Wireless Communications Systems and Standards: A Contemporary Survey

“…The average number of retransmissions in HARQ-incremental redundancy (IR) system (9) and (12) with PER are given in [114], [115]. The metric (9) is evaluated using the input code rate, whereas (12) uses the achieved rate through the number of successful received packets and the total number of transmitted packets.…”

Availability-Reliability-Stability Trade-Offs in Ultra-Reliable Energy-Harvesting Cognitive Radio IoT Networks

“…Therefore, both data-and energy-causality should simultaneously be taken into account. Nevertheless, note that dataand energy-causality are well-addressed in the mathematical analyses of wireless powered (or RF energy-harvesting) communications [36]- [40], and in simulation-based algorithmic-proposed scenarios [41]- [44]. However, analyzing EH-CR-IoT networks with renewable energy resources is still in its infancy.…”