Multicarrier communication techniques for spectrum sensing and communication in cognitive radios

Farhang‐Boroujeny, Behrouz; Kempter, R.

doi:10.1109/mcom.2008.4481344

Cited by 288 publications

(137 citation statements)

References 11 publications

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“…However, this parameter may not be of special interest due to the introduction of multi-carrier modulation techniques such as Orthogonal Frequency-Division Multiplexing (OFDM). OFDM has gained popularity in the context of DSA/CR, among other reasons, due to its capability to exploit noncontiguous spectrum holes by notching the parts of the carriers overlapping with busy licensed channels [50], [51]. As a result, from the point of view of DSA/CR, the contigu- ous free bandwidth of a spectrum band is not as relevant as the total amount of aggregated free bandwidth (contiguous and non-contiguous) available at any moment.…”

Section: Modelsmentioning

confidence: 99%

Spectrum Usage in Cognitive Radio Networks: From Field Measurements to Empirical Models

López-Benítez

Casadevall

2014

IEICE Trans. Commun.

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SUMMARYCognitive Radio (CR) is aimed at increasing the efficiency of spectrum utilization by allowing unlicensed users to access, in an opportunistic and non-interfering manner, some licensed bands temporarily and/or spatially unoccupied by the licensed users. The analysis of CR systems usually requires the spectral activity of the licensed system to be represented and characterized in a simple and tractable, yet accurate manner, which is accomplished by means of spectrum models. In order to guarantee the realism and accuracy of such models, the use of empirical spectrum occupancy data is essential. In this context, this paper explains the complete process of spectrum modeling, from the realization of field measurements to the obtainment of the final validated model, and highlights the main relevant aspects to be taken into account when developing spectrum usage models for their application in the context of the CR technology. key words: cognitive radio, dynamic spectrum access, spectrum usage, spectrum measurements, spectrum models

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Section: Modelsmentioning

confidence: 99%

Spectrum Usage in Cognitive Radio Networks: From Field Measurements to Empirical Models

López-Benítez

Casadevall

2014

IEICE Trans. Commun.

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“…FarhangBoroujeny and C. H. (George) Yuen(2009), presents a tutorial review relating the classical works on FBMC systems, developed prior of the era of OFDM, to the main filter bank design approaches used today for FBMC systems. The paper also reviews the recent novel developments in the design of FBMC systems that are tuned to cope with fast fading wireless channels [8].N. Moret and A. M. Tonello (2009) ,address the efficient realization of a filtered multitone (FMT) modulation system.…”

Section: Related Work: Signal Processing Prospectives In Cognitive Radiomentioning

confidence: 99%

Performance Analysis of Filter Bank Multicarrier Cognitive Radio for Physical Layer under Binary Symmetric Radio Fading Channel

Kang¹,

Vig²

2014

IJCA

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The wireless communication has undergone a revolution due to advancements in technology. For each new user or application to be a part of communication network the preliminary requirement is the allocation of frequency spectrum band. This frequency band is a limited resource and it is impossible to expand its boundaries. So the need is to employ intelligent, adaptive and reconfigurable communication systems which can investigate the requirements of the end user and assign the requisite resources in contrast to the traditional communication systems which allocate a fixed amount of resource to the user under adaptive, autonomic and opportunistic cognitive radio environment. Cognitive Radio(CR) Technology has emerged from software defined radios wherein the key parameters of interest are frequency, power and modulation technique adopted. The role of Cognitive Radio is to alter these parameters under ubiquitous situations. The Spectrum Sensing is an important task to determine the availability of the vacant channels to be utilised by the secondary users without posing any harmful interference to the primary users. In Multicarrier Communication using Digital Signal Processing Techniques, Filter Bank Multi Carrier has an edge over other technologies in terms of Bandwidth and Spectral Efficiency. The present paper deals with the Multi Rate FIR Decimation and Interpolation Filter approach for physical layer of Cognitive Radio under Binary Symmetric fading channel environment.

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“…Multi-Input Multi-Output (MIMO) is the most widelyused technology in current and future wireless communicationsystems. Since OFDM can naturally provide flexibility to fill inspectrum holes over a wide bandwidth, it has been considered as one of the best candidates for the physical layer of CR systems [3], [4].The channel state information (CSI) is crucial for CR systems [5].…”

Section: Imentioning

confidence: 99%

An Efficient Performance of Mimo - Ofdm Based Cognitieve Radio System for Arrays Signal Processing

Farhood¹,

Kamilnaji²

2013

IOSR-JECE

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I.Introduction The use of the radio spectrum is regulated by governmental rules. Almost allparts of the radio spectrum are licensed today. The FCC published a thesis in [1] where the spectrum use in the United States is presented in the aim of betterspectrum utilization.On the other hand, studies have shownthat major licensed bands are largely underutilized. This hasinitiated the idea of cognitive radio (CR), where secondaryusers are allowed to utilize the licensed bands without causing armful interference to the licensed or primary users [2].The CR technology has the potential to significantly increasethe efficiency of the spectrum utilization while maintaining the QoS requirement of the primary users. Multi-Input Multi-Output (MIMO) is the most widelyused technology in current and future wireless communicationsystems. Since OFDM can naturally provide flexibility to fill inspectrum holes over a wide bandwidth, it has been considered as one of the best candidates for the physical layer of CR systems [3], [4].The channel state information (CSI) is crucial for CR systems [5].In practice, the CSI can be estimated by using pilot tones. The selection of pilot tones will significantly affect the channel estimation performance. For conventional OFDM systems where all subcarriers can be used for transmission, the issue of pilot design has been well studied [6]. However, these methods are not effective for OFDM-based CR systems, since the subcarriers used by the primary users cannot be employed by the secondary users. Hence the available subcarriers for the secondary users may be non-contiguous which brings new challenges to pilot design.The simplest pilot design for OFDM-based CR system is to predesign pilot tones for the conventional OFDM system and then deactivates those tones already used by the primaryusers according to the result of spectrum sensing. At the receiver, the remaining activated pilot tones are used forchannel estimation. Directly implementing channel estimationbased on such pilot pattern leads to poor performance [7].To obtains satisfactory channel estimation performance, a shift pilot scheme is proposed in [7]. After predesigning pilot tonesand deactivating some of them according to the spectrumsensing result, this scheme selects some activated data subcarriersas the new pilot tones. Specifically, when a pilot toneis deactivated, its nearest activated data subcarrier is then usedas the new pilot tone. The similar idea can be also found in [8], [9]. Although such a scheme outperforms the aforementioned done, it cannot provide satisfactory performance in all cases.This is mainly because the positions of pilot tones are notoptimized.In this thesis, we propose a new practical pilot design method for MIMO-based CR systems. Unlike the above twoschemes, the proposed one does not predesign the pilot tones.The pilot design is performed after spectrum sensing (i.e.,after the set of activated subcarriers is obtained). To obtaina low-complexity method, we first formulate the pilot designin terms of a new optimiza...

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Multicarrier communication techniques for spectrum sensing and communication in cognitive radios

Cited by 288 publications

References 11 publications

Spectrum Usage in Cognitive Radio Networks: From Field Measurements to Empirical Models

Spectrum Usage in Cognitive Radio Networks: From Field Measurements to Empirical Models

Performance Analysis of Filter Bank Multicarrier Cognitive Radio for Physical Layer under Binary Symmetric Radio Fading Channel

An Efficient Performance of Mimo - Ofdm Based Cognitieve Radio System for Arrays Signal Processing

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