Harmonic power detection in wideband cognitive radios

Sheikh, F.; Masud, Shahid; Bing, Benny

doi:10.1049/iet-spr:20070221

Cited by 6 publications

(9 citation statements)

References 5 publications

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“…The FFT technique can be used to further reduce computational complexity if M is the power of two. The proposed PFB-based sensing should also be compared with the Thomson's multitaper (MT) and wavelet transform (WT) based sensing methods, which were both proved to be promising choices for spectrum sensing [46,49]. It is seen that the phase decomposition structure in Figure 3 by exploiting the polyphase property of filter banks makes the PFB-based sensing be implemented without the penalty of increased complexity, because the M channel filters can be implemented at the cost of one low-pass filter.…”

Section: Discussionmentioning

confidence: 99%

“…The computational complexities of the PFB-based sensing and the PSE-based sensing are presented in Table II. The detailed analysis of computational complexity of MT-based and WT-based methods was reported in [49]. The added implementation complexity compared with the PSE would not be an issue in a practical application of CR systems.…”

Section: Discussionmentioning

confidence: 99%

“…In the literature [49,50], the variances 2 H 0 and 2 H 1 in (18) and (22) were simply regarded as the noise variance 2 n and the signal-plus-noise variance 2 n C 2 s , respectively, and thus the same theoretical threshold was used to implement the subband detection for both windowed FFT and filter bank based spectrum analyzer. For more precise detection and fair detection performance comparison, more stringent requirement for defining a proper detection threshold for various spectrum analyzers should be considered.…”

Section: Analytic Expressions Of Detection Probability and False Alarmentioning

confidence: 99%

“…A spectrum sensing algorithm for wideband CR systems was proposed in [34] by exploiting the sensed spectrum discontinuity properties. The previous works using PFB and energy detector for multi-band sensing can be found in [49,50], wherein the performance of the PFB-based multi-band sensing was evaluated in comparison with conventional periodogram spectrum estimator (PSE), and the final simulation results demonstrated the significant advantage of the PFB multi-band sensing compared with conventional PSE. These two sensing stages collaborate with each other to enhance the accuracy of spectrum sensing performance.…”

mentioning

confidence: 99%

“…This means that the PFB structure for communication will offer a new opportunity for sensing at no extra cost. The previous works using PFB and energy detector for multi-band sensing can be found in [49,50], wherein the performance of the PFB-based multi-band sensing was evaluated in comparison with conventional periodogram spectrum estimator (PSE), and the final simulation results demonstrated the significant advantage of the PFB multi-band sensing compared with conventional PSE. The previous works using PFB and energy detector for multi-band sensing can be found in [49,50], wherein the performance of the PFB-based multi-band sensing was evaluated in comparison with conventional periodogram spectrum estimator (PSE), and the final simulation results demonstrated the significant advantage of the PFB multi-band sensing compared with conventional PSE.…”

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confidence: 99%

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Polyphase filter bank based multi‐band spectrum sensing in cognitive radio systems

Zhang

Ruyet

Roviras

2014

Int J Communication

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Spectrum sensing has been identified as an essential enabling functionality for cognitive radio (CR) systems to guarantee that CR users could share the spectrum resource with licensed users on a non-interfering basis. Recently, simultaneous sensing of multi-band licensed user activity has been attracting more and more research interest. Generally, the multi-band sensing is implemented through energy detection by estimating power spectral density. In this paper, we investigate a multi-band energy detection architecture based on different polyphase filter banks (PFBs), which aim to reliably sense multiple active bands by exploiting the low power leakage property of PFB. We have theoretically derived the closed-form expressions of detection probability and false alarm probability for PFBs and fast Fourier transform based detectors, respectively. Theoretical detection thresholds are therefore computed, which ensures a fair comparison for different detectors. Final experimental results are presented to verify our theoretical analysis and demonstrate that PFBs based sensing architecture exhibits better sensing performance than the conventional FFT.Spectrum sensing on a single frequency band has a relatively rich literature [29,30]. However, the literature of multi-band sensing that monitors multiple frequency bands simultaneously is very limited. The basic concept of multi-band sensing is to firstly estimate the power spectral density (PSD) and then power detection (which is simple and can locate spectrum occupancy information quickly) is applied in the frequency domain based on the observed power spectrum [31][32][33]. A spectrum sensing algorithm for wideband CR systems was proposed in [34] by exploiting the sensed spectrum discontinuity properties. In [35], a wideband dual-stage sensing technique: a coarse and a fine spectrum sensing architecture was proposed. These two sensing stages collaborate with each other to enhance the accuracy of spectrum sensing performance. In [36], three widely used spectrum estimation methods, weighted overlapped segment averaging approach, multi-taper spectrum estimator, and multiple signal classification algorithm, were introduced and compared for wideband detection. In [37], a novel approach called segmented periodogram for wideband spectrum segmentation was proposed. The proposed scheme is based on the posterior expectation of the piece-wise flat realizations of the underlying signal spectrum, which is obtained using the reversible jump Markov chain Monte Carlo technique. The authors in [38] considered joint decisions over multiple frequency bands. The spectrum sensing problem is formulated as a class of optimization problems in interference limited cognitive radio networks. The theoretical analysis of spectrum sensing using multitaper spectrum was investigated in [39], where analytic detection probabilities have been derived for multitaper-based detection schemes, which is demonstrated to be more robust to the noise uncertainty compared with energy-based detectors. In [40], the aut...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Analytic Expressions Of Detection Probability and False Alarmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Polyphase filter bank based multi‐band spectrum sensing in cognitive radio systems

Zhang

Ruyet

Roviras

2014

Int J Communication

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Cognitive Radio Spectrum Sensing Based on Wavelet Denoising

Zhao

Guo

2012

Recent Advances in Computer Science and Information Engineering

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Optimality of greedy policy for a class of standard reward function of restless multi-armed bandit problem

Wang

Liu

Chen

2012

IET Signal Process.

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In this paper,we consider the restless bandit problem, which is one of the most well-studied generalizations of the celebrated stochastic multi-armed bandit problem in decision theory. However, it is known be PSPACE-Hard to approximate to any non-trivial factor. Thus the optimality is very difficult to obtain due to its high complexity. A natural method is to obtain the greedy policy considering its stability and simplicity.However, the greedy policy will result in the optimality loss for its intrinsic myopic behavior generally.In this paper, by analyzing one class of so-called standard reward function, we establish the closed-form condition about the discounted factor β such that the optimality of the greedy policy is guaranteed under the discounted expected reward criterion, especially, the condition β = 1 indicating the optimality of the greedy policy under the average accumulative reward criterion. Thus, the standard form of reward function can easily be used to judge the optimality of the greedy policy without any complicated calculation. Some examples in cognitive radio networks are presented to verify the effectiveness of the mathematical result in judging the optimality of the greedy policy. Index TermsPartially observed Markov decision process (POMDP), multi-armed restless bandit problems, optimality, greedy policy, cognitive radio

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Harmonic power detection in wideband cognitive radios

Cited by 6 publications

References 5 publications

Polyphase filter bank based multi‐band spectrum sensing in cognitive radio systems

Polyphase filter bank based multi‐band spectrum sensing in cognitive radio systems

Cognitive Radio Spectrum Sensing Based on Wavelet Denoising

Optimality of greedy policy for a class of standard reward function of restless multi-armed bandit problem

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