1,908 research outputs found
Optimal Spectrum Access for a Rechargeable Cognitive Radio User Based on Energy Buffer State
This paper investigates the maximum throughput for a rechargeable secondary
user (SU) sharing the spectrum with a primary user (PU) plugged to a reliable
power supply. The SU maintains a finite energy queue and harvests energy from
natural resources, e.g., solar, wind and acoustic noise. We propose a
probabilistic access strategy by the SU based on the number of packets at its
energy queue. We investigate the effect of the energy arrival rate, the amount
of energy per energy packet, and the capacity of the energy queue on the SU
throughput under fading channels. Results reveal that the proposed access
strategy can enhance the performance of the SU.Comment: arXiv admin note: text overlap with arXiv:1407.726
Optimal Cooperative Cognitive Relaying and Spectrum Access for an Energy Harvesting Cognitive Radio: Reinforcement Learning Approach
In this paper, we consider a cognitive setting under the context of
cooperative communications, where the cognitive radio (CR) user is assumed to
be a self-organized relay for the network. The CR user and the PU are assumed
to be energy harvesters. The CR user cooperatively relays some of the
undelivered packets of the primary user (PU). Specifically, the CR user stores
a fraction of the undelivered primary packets in a relaying queue (buffer). It
manages the flow of the undelivered primary packets to its relaying queue using
the appropriate actions over time slots. Moreover, it has the decision of
choosing the used queue for channel accessing at idle time slots (slots where
the PU's queue is empty). It is assumed that one data packet transmission
dissipates one energy packet. The optimal policy changes according to the
primary and CR users arrival rates to the data and energy queues as well as the
channels connectivity. The CR user saves energy for the PU by taking the
responsibility of relaying the undelivered primary packets. It optimally
organizes its own energy packets to maximize its payoff as time progresses
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