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In this paper a novel delay aware potential field based routing is proposed for cognitive radio. The proposed methods are inspired by potential field techniques applied in robot navigation. The novelty of the proposed methods arises from identifying the analogy between packet routing in wireless networks and obstacle avoidance in robot navigation. This allows for the modeling of desired communication...
An anti-jamming communication game between a cognitive radio enabled secondary user (SU) and a cognitive radio enabled jammer is considered, in which end-user decision making is modeled using prospect theory (PT). More specifically, the interactions between a user and a smart jammer (i.e., their respective choices of transmission probability) are formulated as a game under the assumption that end-user...
The aim of this paper is to study how to enlarge the performance gap between non-orthogonal multiple access (NOMA) and conventional orthogonal multiple access (MA) by applying user pairing. Particularly two user pairing schemes achieving different quality of service (QoS) requirements, namely NOMA with fixed power allocation (F-NOMA) and cognitive radio inspired NOMA (CR-NOMA), are proposed. For F-NOMA,...
A single cognitive radio transmitter-receiver pair shares the spectrum with two primary users communicating with their respective receivers. Each primary user has a local traffic queue, whereas the cognitive user has three queues; one storing its own traffic while the other two are relaying queues used to store primary relayed packets admitted from the two primary users. A new cooperative cognitive...
This paper considers spectrum access in wideband channels and its objective is to design an agile and reliable mechanism for identifying spectrum opportunities. Driven by the need for reducing the time required for identifying spectrum opportunities, the idea of data-adaptive and sequential block sampling is proposed, through which instead of examining each channel individually, a cognitive user takes...
In this paper, distributed iterative time slot allocation algorithms for spectrum sensing information (SSI) sharing in cognitive radio ad hoc networks are proposed. The proposed algorithms are based on a collision detection and acknowledgment scheme, which allows nodes to receive knowledge about collisions with their two-hop neighbors. The nodes use this information to update their operating time...
In this paper, the performance of adaptive modulation in multi-user cognitive radio networks over fading channels is analyzed. Multi-user diversity is considered for opportunistic user selection among multiple secondary users. The analysis is obtained for Nakagami-m fading channels. Both adaptive continuous rate and adaptive discrete rate schemes are analysed in opportunistic spectrum access and spectrum...
A sensing policy for the restless multi-armed bandit problem with stationary but unknown reward distributions is proposed. The work is presented in the context of cognitive radios in which the bandit problem arises when deciding which parts of the spectrum to sense and exploit. It is shown that the proposed policy attains asymptotically logarithmic weak regret rate when the rewards are bounded independent...
Compressive spectrum sensing techniques present many advantages over traditional spectrum sensing approaches, e.g., low sampling rate, and reduced energy consumption. However, when the spectral sparsity level is unknown, there are two significant challenges. They are: 1) how to choose an appropriate number of measurements, and 2) when to terminate the greedy recovery algorithm. In this paper, a compressive...
A quadrature signaling based two-phase cooperation framework for cooperative cognitive radio networking is proposed. By leveraging the degrees of freedom provided by orthogonal modulation, secondary users are able to relay the traffic of primary users and transmit their own in the same time slot without interference. To evaluate the cooperation performance of the proposed framework, a weighted sum...
A significant challenge of cognitive radio (CR) is to perform wideband spectrum sensing in a fading environment. In this paper, a novel multi-rate sub-Nyquist spectrum detection(MSSD) system is introduced for cooperative wideband spectrum sensing in a distributed CR network. Using only a few sub- Nyquist samples, MSSD is able to sense the wideband spectrum without full spectrum recovery. Specifically,...
In this paper a distributed multiagent, multiband reinforcement learning based sensing policy for cognitive radio ad hoc networks is proposed. The proposed sensing policy employs secondary user (SU) collaboration through local interactions. The goal is to maximize the amount of available spectrum found for secondary use given a desired diversity order, i.e. a desired number of SUs sensing simultaneously...
In cognitive radio systems, secondary users can utilize multiple dispersed bands that are not used by primary users. In this paper, time delay estimation of signals that occupy multiple dispersed bands is studied. First, theoretical limits on time delay estimation are reviewed. Then, two-step time delay estimators that provide trade-offs between computational complexity and performance are investigated...
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