Spectrum Sensing in Wideband OFDM Cognitive Radios

Hwang, Chien-Hwa; Lai, Guan-Long; Chen, Shih-Chang

doi:10.1109/tsp.2009.2032453

Cited by 50 publications

(6 citation statements)

References 22 publications

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“…The SS of OFDM signals transmitted according to the described transmission process has been analysed in different studies in the literature [10,11,19,[24][25][26][27][28][29][30][31][32][33][34][35]. In Table 1, an overview of ED methods and their corresponding merits are presented.…”

Section: Related Work On the Ss Of Ofdm Signalsmentioning

confidence: 99%

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A Survey on the Energy Detection of OFDM Signals with Dynamic Threshold Adaptation: Open Issues and Future Challenges

Lörincz

Ramljak²,

Begušić

2021

Sensors

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Cognitive radio (CR), as a concept based on the ability to detect and share the unutilised spectrum, has been envisioned as a promising candidate to improve the efficiency of frequency spectrum assignments. For the realisation of the CR concept, energy detection (ED), as one of the available spectrum sensing methods, is broadly considered because of its low computational complexity and implementation costs. Due to the vast usage of the orthogonal frequency division multiplexing (OFDM) technique in contemporary communication systems, the ED of OFDM signals in the CR networks has become important for practical realisation. Since the ED accuracy of the OFDM signals can be improved by the sensing threshold adaptation, this paper surveys the impact of noise variations and dynamic threshold (DT) adaptation on the ED performance of OFDM signals. Analyses were performed by the simulation of the ED related to OFDM signals transmitted in the margin or rate adaptive and combined margin and rate adaptive OFDM systems. The results obtained through extensive simulations provide fundamental insights into how different factors, including the transmission power, the signal to noise ratio, the false alarm probability and the sample quantity, affect the ED efficiency. Comprehensive analyses of the obtained results indicate the main ED weaknesses and how the appropriate selection of analysed factors can enhance the ED processes for different OFDM systems. The observed ED weaknesses were further thoroughly surveyed, and the open issues and challenges related to the enhancement of the main ED limitations have been elaborated. The presented survey results can serve as a basis for the improvement of a broadly accepted ED method in CR networks.

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Section: Related Work On the Ss Of Ofdm Signalsmentioning

confidence: 99%

“…Only the ED approach with fixed detection threshold [7,18,24,27,34] No influence related to the impact of NU and DT adaptation…”

Section: Approach Analysed In the Literature Description Of The Analysed Approach The Merit Of The Analysed Approachmentioning

confidence: 99%

A Survey on the Energy Detection of OFDM Signals with Dynamic Threshold Adaptation: Open Issues and Future Challenges

Lörincz

Ramljak²,

Begušić

2021

Sensors

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“…In this section, simulations based on MATLAB platform are made to examine the performance of the proposed efficiency functions in (37)-(39) and the novel sensing strategies in (43). Orthogonal Frequency Division Multiplexing (OFDM) signal [32] is chosen as the test signal (PU) for its generality and popularity in wireless communication networks, whose center frequency is denoted as for statistics number 5.…”

Section: Simulation and Discussionmentioning

confidence: 99%

Complexity based Sensing Strategy for Spectrum Sensing in Cognitive Radio Networks

2019

KSII TIIS

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Spectrum sensing has attracted much attention due to its significant contribution to idle spectrum detection in Cognitive Radio Networks. However, specialized discussion is on complexity-based sensing strategy for spectrum sensing seldom considered. Motivated by this, this paper is devoted to complexity-based sensing strategy for spectrum sensing. Firstly, three efficiency functions are defined to estimate sensing efficiency of a spectrum scheme. Then a novel sensing strategy is proposed given sensing performance and computational complexity. After that, the proposed sensing strategy is extended to energy detector, Cyclostationary feature detector, covariance matrix detector and cooperative spectrum detector. The proposed sensing strategy provides a novel insight into sensing performance estimation for its consideration of both sensing capacity and sensing complexity. Simulations analyze three efficiency functions and optimal sensing strategy of energy detector, Cyclostationary feature detector and covariance matrix detector.

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“…The final stage in the design of spectrum sensing system is the energy detector. For each subcarrier, the total energy of the shaping filter output is compared with a certain threshold to make right decision if there is a primary signal in the licensed According to the number of operations and logic elements required for each stage and the value of (N) in Table .4, the total number of arithmetic operations and logic elements needed to implement the three stages of the sensing system are shown in Table (5).…”

Section: Logic Elements (𝒍𝒐𝒈 𝟐 𝑵 − Counter) 1 (N) D/ff For Convolutio...mentioning

confidence: 99%

“…A summary of spectrum sensing algorithms were introduced in [4]. Hwang et al [5] reported on sensing OFDM signals based on the energy detector. They showed that such type needs high signal to noise ratio to sense the spectrum properly.…”

Section: Introductionmentioning

confidence: 99%

Low Complexity Spectrum Sensing System for GFDM Cognitive Radio Signals

Chaiel¹

2014

ETJ

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Cognitive radio is a promising technology that aims to use the transmission spectrum efficiently. Each cognitive transmission process consists typically of two phases. During the first phase, which is called sensing phase, cognitive system attempts to detect an available spectrum hole. While in the second phase, data transmission phase, the secondary user data is transmitted to the destination via detected hole. The throughput of the cognitive radio system is mainly depending on the ratio of the transmission time to the sensing time. To reduce the sensing time, this paper suggests a design of simple spectrum sensing system capable for detecting Generalized Frequency Division Multiplexing (GFDM) signals. The reduction in sensing time is based on using XilinixVirtix-6 Field Programmable Gate Array (FPGA) as a target device for implementation the proposed design, which operates at 600 MHz clock frequency. This work includes a discussion of more than one approach to reduce the arithmetic operations needed to implement a sensing system with 250 subcarriers. The simulation results show that the power consumption represents the main challenge of such implementation.

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Spectrum Sensing in Wideband OFDM Cognitive Radios

Cited by 50 publications

References 22 publications

A Survey on the Energy Detection of OFDM Signals with Dynamic Threshold Adaptation: Open Issues and Future Challenges

A Survey on the Energy Detection of OFDM Signals with Dynamic Threshold Adaptation: Open Issues and Future Challenges

Complexity based Sensing Strategy for Spectrum Sensing in Cognitive Radio Networks

Low Complexity Spectrum Sensing System for GFDM Cognitive Radio Signals

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