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Cognitive radio (CR) is considered as a key enabling technology for dynamic spectrum access to improve spectrum efficiency. Although the CR concept was invented with the core idea of realizing "cognition", the research on measuring CR cognition capabilities and intelligence is largely open. Deriving the intelligence capabilities of CR not only can lead to the development of new CR technologies,...
Cognitive radio emerges as a promising technology to improve the utilization of the allocated spectrum. In a cognitive radio network, secondary users (SUs) need to sense the spectrum to obtain currently available channels and have to vacate the occupied channels when primary users (PUs) return. In cognitive radio networks, establishing a link through a common available channel is defined as the rendezvous...
In this paper, we propose the concept of "channel+ beam" hando2642 (CBH) in cognitive radio networks (CRNs) with multi-beam smart antennas (MBSAs). We address the multi-class spectrum hando2642 issue, based on the user priority, by using the mixed Preemptive/Non-Preemptive M/G/1 queueing model with discretion rule. The discretion rule sets the threshold for the preemption of the low-priority...
Transitional Region Phenomenon leads to the existence of lossy links in wireless networks, which results in a transmission between two users who are theoretically connected under the Deterministic Network Model cannot be guaranteed. Therefore, we focus on a more practical network model - Probabilistic Network Model (PNM) which can better characterize the lossy links in wireless networks. To be specific,...
In this paper, an underlay based cognitive radio network (CRN) consisting of a secondary base station (SBS), a secondary receiver (SR), an energy harvesting node (EHN), and a primary transmitter-receiver (PT-PR) pair, is considered. The EHN is assumed to have a power splitter (PS) at the receiver to decode information and harvest energy simultaneously from the SBS transmission, thus reducing the secrecy...
The asymptotic sum rate performance of multi-cell/multi-user cognitive massive multiple-input multiple-output (MIMO) systems with underlay spectrum sharing is investigated. Specifically, each cell consists of a licensed (primary) multi-user massive MIMO system and a cognitive (secondary) multi-user MIMO system which is allowed to utilize the licensed frequency spectrum provided that the intra-cell...
Cognitive radio is an optimistic technology to implement the concept of dynamic spectrum access and provide a flexible way to share the spectrum among the primary and secondary users. In this paper, a game theoretic-based model is presented using the concept of Nash Equilibrium for spectrum sharing. In this model, interference and number of radios on each link are considered as parameters for designing...
Spectrum trading not only improves spectrum utilization but also benefits both secondary users (SUs) with more accessing opportunities and primary users (PUs) with monetary gains. Although existing centralized designs consider the special features of spectrum trading (e.g., frequency reuse, interference mitigation, multi-radio multi- channel transmissions, etc.), they have to deploy new infrastructure,...
Spectrum auctions provide a platform for licensed spectrum users to share their underutilized spectrum with unlicensed users. Existing spectrum auctions either use the protocol interference model to characterize interference relationship as binary relationship, or do not allow the primary and secondary users to share channels simultaneously. To fill this void, we design SPA, a spectrum single-sided...
Correlation-based algorithms are low-complexity spectrum sensing methods requiring little knowledge on primary signals or noise signals. However, their detection performance severely degrades in the low signal-to-noise ratio (SNR) regime with low signal correlation, which happens to be quite common in practice. In this paper, a weighted correlation- based spectrum sensing scheme and its simplified...
Spectrum trading benefits secondary users (SUs) with accessing opportunities and primary users (PUs) with monetary gains in cognitive radio networks. In the spectrum trading market, bidding privacy is a serious concern for SUs, since untrustworthy PUs or spectrum traders may leverage bidding information to manipulate the trading or leak SU's bids to other SU competitors for illegal gains. Current...
In cognitive radio networks, the performance of energy detection will be degraded significantly due to the cluster overlapping caused by noise uncertainty. To alleviate the noise uncertainty effect, a novel machine learning algorithm is proposed in this paper for cooperative spectrum sensing. The proposed algorithm incorporates fuzzy support vector machine and nonparallel hyperplane support vector...
Wideband spectrum sensing is a critical functionality in cognitive radio networks to enable dynamic spectrum sharing, but entails a major implementation challenge in compact commodity radios with restricted energy and computation capabilities. Exploiting jointly sparse nature of multiband signals, this paper proposes an efficient blind sub-Nyquist cooperative wideband spectrum sensing scheme, which...
Recently, cognitive radio (CR) technology is proposed to be combined with femtocell networks, which enables femtocells to access the available spectrum bands in an opportunistic manner. In practice, the available spectrums in CR femtocell networks are heterogeneous and range from hundreds of megahertz to several gigahertz. These heterogeneous spectrums have very different path- losses which may result...
In cognitive radio networks, multichannel spectrum sensing yield accurate results compared to single channel sensing schemes. However, often realistic correlation among multiple sensing channels is ignored. In this paper, we investigate the performance of a cognitive radio spectrum sensing systems considering more realistic exponential correlation among multiple sensing channels. Closed-form expressions...
Dynamic spectrum access is an important issue in cognitive radio networks (CRNs) as secondary users (SUs) can benefit from accessing the vacant licensed channels of primary users (PUs). In this paper, we consider the problem of competitive distributed spectrum access in CRNs with quality of service (QoS) constraints. We first propose a distributed matching algorithm (DMA) to handle spectrum access...
In this paper, we propose a novel Media Access Control (MAC) scheme for Cognitive Radio Ad Hoc Networks (CRAHNs). The scheme includes two mechanisms. One mechanism is called Exposed Terminal Secondary users Communication (ETSC), which allows a Secondary User (SU) to continue communication attempt even when the occupied channel could be used by a new Primary User (PU). The other is called Four-Stage...
Abstract-We propose a novel RF signal classification method based on sparse coding, an unsupervised learning method popular in computer vision. In particular, we employ a convolutional sparse coder that can extract high-level features of an unknown received signal by maximal similarity matching against an overcomplete dictionary of filter patterns. Such dictionary can be either generated or learned...
Abstract-In cognitive radio networks, secondary users (SUs) face two conflicting objectives. Each SU seeks to minimize the sensing duration while maximizing the detection probability of primary users (PU) to avoid interfering with their transmissions. Both objectives have a substantial effect on energy efficiency. This paper investigates a noncooperative setting for selecting the sensing duration...
As a critical technique to support the multimedia services - the major traffic in cooperative cognitive radio networks (CRNs), the statistical quality-of-service (QoS) technique has been proved to be effective in statistically guaranteeing delay-bounded video transmissions over the time- varying wireless channels. On the other hand, in modern cooperative CRNs, the full-duplex spectrum sensing (FD-SS)...
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