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At present, spectrum scarcity is a major concern in the field of mobile communication. The necessity of spectrum is increasing gradually because the usage of wireless communication is rising tremendously. Cognitive radio (CR) is capable of dealing with this problem. This is referred to as an intelligent and reconfigurable radio which enables efficient usage of unused spectrum while avoiding any kind...
The wireless sensor network has importance on account of recent improvement of information technology. Micro-electrical mechanical system is used to evolve sensors over the last past decades. The enormous numbers of sensors are redistributed for sensing as well as accumulating data from its neighborhood through routing protocol. Industrial township area yields smoke on account of burning of diesel,...
Spectrum sensing and sharing are challenging task in asynchronous cognitive networks (CNs), where there is nc synchronization between primary and secondary users (PUs and SUs). In this paper, we propose combination of cooperative spectrum sensing and full-duplex communication for improving quality and throughput of both primary and secondary users in asynchronous CNs. More specifically, we have studied...
The paper investigates the problem of maximizing the expected achievable sum rate in a fading multiple access cognitive radio network when secondary user (SU) transmitters have energy harvesting capability, and perform cooperative spectrum sensing. We formulate the problem as maximization of throughput of the cognitive multiple access network over a finite time horizon subject to a time averaged interference...
Cognitive radio sensor network (CRSN) is a novel wireless sensor network, which can effectively alleviate the scarcity of spectrum resource by equipping the cognitive technology. Usually, CRSN deploys numerous sensor nodes around the monitoring area. But the energy and storage of those nodes are both limited. Compared with the centralized CRSN, we focus more on a decentralized situation without the...
In this paper, we have exploited the novel hybrid-cum-improved spectrum access strategy to significant improvement in the throughput and data-loss rate. This proposed strategy is comprise of hybrid spectrum access and improved frame structure strategies for the cognitive radio communication system. In addition to this, the mathematical expressions of throughput for these approaches are also presented...
Register files (RFs) consume significant power in low-power processors, and their specifications vary substantially for different applications. Challenges exist in identifying the appropriate RF design and optimizing RFs for different specifications. This paper not only explores methodologies of designing low power and high performance RFs and it also extends a virtual prototyping (ViPro) tool to...
Recently there have been numerous studies exploring the benefits of the coalition formation in a cognitive radio network and it has been shown that coalition formation tends to improve the performance of cognitive radio networks. In this paper, we use the concepts from matching theory to form coalitions of varying size among cognitive radio users for cooperative spectrum sensing under target detection...
In this paper we consider distributed cognitive radio networks (CRNs) with channel aggregation (CA) scheme where there are multiple wireless channels and multiple secondary users (SUs). SUs in CRNs with CA can transmit bits of data through more than one idle channels which are not used by primary users (PUs). SUs decide whether to access idle channels or not based on the access probability (AP), and...
In this paper, a distributed fair algorithm is proposed to address the resource allocation problem in the cognitive femtocell network. The cognitive functionalities equipped in femtocells enable us to effectively identify the qualified resource blocks (RBs), thus we can mitigate inter-cell interference. By exploiting the satisfaction degree and the channel state difference, the proposed distributed...
One of the major challenges in Dynamic Spectrum Access (DSA) systems is to guarantee a required level of Quality of Service (QoS) to secondary users of the spectrum. In this paper, we propose efficient algorithms for deriving optimal policies for the sensing / transmitting trade-off in hardware-constrained DSA systems. Unlike previous approaches which seek to maximize mean data rate for the secondary...
One of the approaches in cognitive radio is the opportunistic spectrum access (OSA), which enables secondary users (SUs) to access the licensed frequency bands that are detected to be idle. Though there have been a few updates on the throughput aspects of SUs in OSA not much work has been done taking into account the sensing errors, spectrum occupancy probabilities as well as the transmission frame...
This paper uses send-on-delta (SoD) strategies to reduce the sampling error instead of reducing the amount of sent messages. For this purpose, we present a procedure that selects an appropriate delta value for a given mean transmission rate. Signals are then sampled using the send-on-delta strategy with the selected delta value. The amount of sent messages will be higher in time intervals where the...
RF energy harvesting can be used to power communication devices so that perpetual operation of such devices can be ensured. We consider a RF energy harvesting underlay cognitive radio system operating in slotted fashion. The primary user (PU) is equipped with a reliable power source and transmits with a constant power in all the slots. However, the secondary user (SU) harvests energy from primary's...
Wireless Body Area Network (WBAN) has been considered as a revolutionary technology to address current healthcare needs. However, before the extensive deployment of WBAN, one main challenge to be met is how to balance the trade-off between data transmission rate and energy efficiency. In this paper, we utilize WBAN's spatial correlation characteristics during movement and propose an efficient cross-layer...
This paper proposes a reserved channel based spectrum handover mechanism for cognitive heterogeneous networks (HetNet). To properly handover secondary users from Macro to Femto base stations and maintaining an acceptable protection on the primary users, we propose a priority-based scheme in which several channels are reserved only for handover of secondary users while the rest of channels can be shared...
In this paper, we study the impact of eigenvalue-based spectrum sensing techniques in the achievable throughput of the secondary cognitive radio network. For this analysis, the channel between the primary and secondary users is modeled as a complex Nakagami-m distribution, in order to investigate the effects of not only the channel envelope, but also the novel non-uniform phase distribution in the...
The paper presents cooperative communication based wireless sensor network for monitoring Green house related parameters such as Temperature, humidity and Carbon-di-oxide. The system is demonstrated by using network simulator NS2 with increased network capacity to suit large geo graphical areas. The comparison results show that cooperative transmission provides better performance than non-cooperative...
Ensuring fair co-existence between unlicensed LTE and WiFi networks is currently of major concern to both cellular operators and WiFi providers. Two main unlicensed LTE approaches currently being discussed, namely Carrier Sense Adaptive Transmission (CSAT) and Listen Before Talk (LBT). While these mechanisms differ in their compatibility with existing LTE specifications and regulatory compliance in...
Licensed-assisted access (LAA), which conveys control signal via licensed anchor carrier and data information via both licensed and unlicensed bands, is a promising solution to enhance the throughput of wireless communications. In view of the potential impact on the incumbent services in the unlicensed band, how to design the medium access control (MAC) protocol for LAA system to make fair and friendly...
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