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SNR Wall Effect Alleviation by Generalized Detector Employed in Cognitive Radio Networks.

Shbat MS, Tuzlukov V - Sensors (Basel) (2015)

Bottom Line: The most commonly used spectrum sensing techniques in cognitive radio (CR) networks, such as the energy detector (ED), matched filter (MF), and others, suffer from the noise uncertainty and signal-to-noise ratio (SNR) wall phenomenon.These detectors cannot achieve the required signal detection performance regardless of the sensing time.The simulation results confirm our theoretical issues and effectiveness of GD implementation in CR networks based on antenna array.

View Article: PubMed Central - PubMed

Affiliation: School of Electronics Engineering, College of IT Engineering, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701, Korea. modboss80@gmail.com.

ABSTRACT
The most commonly used spectrum sensing techniques in cognitive radio (CR) networks, such as the energy detector (ED), matched filter (MF), and others, suffer from the noise uncertainty and signal-to-noise ratio (SNR) wall phenomenon. These detectors cannot achieve the required signal detection performance regardless of the sensing time. In this paper, we explore a signal processing scheme, namely, the generalized detector (GD) constructed based on the generalized approach to signal processing (GASP) in noise, in spectrum sensing of CR network based on antenna array with the purpose to alleviate the SNR wall problem and improve the signal detection robustness under the low SNR. The simulation results confirm our theoretical issues and effectiveness of GD implementation in CR networks based on antenna array.

No MeSH data available.


Related in: MedlinePlus

Signals at the GD PF and AF outputs: (a) GD AF response and noise; (b) GD PF response and noise; (c) GD PF response and PU signal.
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sensors-15-16105-f003: Signals at the GD PF and AF outputs: (a) GD AF response and noise; (b) GD PF response and noise; (c) GD PF response and PU signal.

Mentions: The GD PF and AF can be considered as the linear systems, for example, as the bandpass filters, with the impulse responsesand, respectively. For simplicity of analysis, we assume that these filters have the same amplitude-frequency characteristics or impulse responses by shape. Moreover, the GD AF central frequency is detuned with respect to the GD PF central frequency on such a value that the information signal (the PU signal) cannot pass through the GD AF. Thus, the PU signal and noise can appear at the GD PF output and the only noise is appeared at the GD AF output (see Figure 3). If a value of detuning between the GD AF and PF central frequencies is more than 4 or 5, whereis the PU signal bandwidth, the processes at the GD AF and PF outputs can be considered as the uncorrelated and independent processes and, in practice, under this condition, the coefficient of correlation between GD PF and AF output processes is not more than 0.05 that was confirmed experimentally [31,32].


SNR Wall Effect Alleviation by Generalized Detector Employed in Cognitive Radio Networks.

Shbat MS, Tuzlukov V - Sensors (Basel) (2015)

Signals at the GD PF and AF outputs: (a) GD AF response and noise; (b) GD PF response and noise; (c) GD PF response and PU signal.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541870&req=5

sensors-15-16105-f003: Signals at the GD PF and AF outputs: (a) GD AF response and noise; (b) GD PF response and noise; (c) GD PF response and PU signal.
Mentions: The GD PF and AF can be considered as the linear systems, for example, as the bandpass filters, with the impulse responsesand, respectively. For simplicity of analysis, we assume that these filters have the same amplitude-frequency characteristics or impulse responses by shape. Moreover, the GD AF central frequency is detuned with respect to the GD PF central frequency on such a value that the information signal (the PU signal) cannot pass through the GD AF. Thus, the PU signal and noise can appear at the GD PF output and the only noise is appeared at the GD AF output (see Figure 3). If a value of detuning between the GD AF and PF central frequencies is more than 4 or 5, whereis the PU signal bandwidth, the processes at the GD AF and PF outputs can be considered as the uncorrelated and independent processes and, in practice, under this condition, the coefficient of correlation between GD PF and AF output processes is not more than 0.05 that was confirmed experimentally [31,32].

Bottom Line: The most commonly used spectrum sensing techniques in cognitive radio (CR) networks, such as the energy detector (ED), matched filter (MF), and others, suffer from the noise uncertainty and signal-to-noise ratio (SNR) wall phenomenon.These detectors cannot achieve the required signal detection performance regardless of the sensing time.The simulation results confirm our theoretical issues and effectiveness of GD implementation in CR networks based on antenna array.

View Article: PubMed Central - PubMed

Affiliation: School of Electronics Engineering, College of IT Engineering, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701, Korea. modboss80@gmail.com.

ABSTRACT
The most commonly used spectrum sensing techniques in cognitive radio (CR) networks, such as the energy detector (ED), matched filter (MF), and others, suffer from the noise uncertainty and signal-to-noise ratio (SNR) wall phenomenon. These detectors cannot achieve the required signal detection performance regardless of the sensing time. In this paper, we explore a signal processing scheme, namely, the generalized detector (GD) constructed based on the generalized approach to signal processing (GASP) in noise, in spectrum sensing of CR network based on antenna array with the purpose to alleviate the SNR wall problem and improve the signal detection robustness under the low SNR. The simulation results confirm our theoretical issues and effectiveness of GD implementation in CR networks based on antenna array.

No MeSH data available.


Related in: MedlinePlus