Dynamic selection of CWmin in cognitive radio networks for protecting IEEE 802.11 primary users

Umebayashi, Kenta; Suzuki, Yasuo; Lehtomäki, Janne

doi:10.4108/icst.crowncom.2011.245876

Cited by 14 publications

(8 citation statements)

References 10 publications

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“…Therefore, it is possible to achieve accurate spectrum sensing performance with low complexity [4], [5]. In addition, the statistics are useful for designing SU's medium access control protocol effectively [6]. Moreover, for more dynamic and flexible spectrum utilization in future wireless networks, spectrum utilization statistics will be very useful.…”

Section: Introductionmentioning

confidence: 99%

Duty cycle and noise floor estimation with Welch FFT for Spectrum Usage Measurements

Umebayashi

Takagi

Ioroi

et al. 2014

Proceedings of the 9th International Conference on Cognitive Radio Oriented Wireless Networks

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In dynamic spectrum access, a new wireless system (secondary user: SU) can utilize the spectrum licensed to an existing wireless system (primary user: PU) while the spectrum is vacant. For accomplishing effective and reliable spectrum utilization, statistics of the spectrum usage by the PU, such as duty cycle (DC), are useful for the SU. In this paper, we investigate accurate spectrum measurement technique with energy detector for obtaining the accurate duty cycle (DC) estimation with a noise floor (NF) estimation which is used for proper threshold setting. In one conventional method, median filtered FCME (Forward Consecutive Mean Excision), frequency selectivity due to interference among spectra of independent symbols degrades the NF and DC estimation performances. In this paper, we propose Welch FFT based NF estimation and DC estimation since Welch FFT has a potential to suppress the effect of the frequency selectivity. We analytically obtain probability density function (PDF) and right tail probability of output of the Welch FFT process and this analysis enables to set proper threshold. Numerical results will show that the proposed method can achieve better NF estimation performance. In addition, the NF estimation improvement and the suppression of frequency selectivity by the Welch FFT can provide around 15 dB SNR gain in the DC estimation performance.

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Section: Introductionmentioning

confidence: 99%

Duty cycle and noise floor estimation with Welch FFT for Spectrum Usage Measurements

Umebayashi

Takagi

Ioroi

et al. 2014

Proceedings of the 9th International Conference on Cognitive Radio Oriented Wireless Networks

Self Cite

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“…In [8], statistical channel utilization model was also used to improve spectrum sensing performance. Channel occupancy rate is also useful to achieve efficient MAC protocol design and spectrum management method as has been demonstrated in [9]- [11].…”

Section: Introductionmentioning

confidence: 99%

Development of a measurement system for spectrum awareness

Umebayashi¹,

Tiiro²,

Lehtomäki³

2014

Proceedings of the 1st International Conference on 5G for Ubiquitous Connectivity

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Dynamic spectrum access (DSA) is an attractive approach to solve the spectrum scarcity problem. Among DSA techniques, spectrum overlay is an approach where the spectrum licensed to a primary user (PU) is shared by a secondary user (SU) while protecting the PU from the interference caused by SU spectrum reuse. In the case where PU traffic is dynamic, spectrum sharing is difficult as satisfying requirements of spectrum sensing, the challenging accuracy, quickness and low cost requirements in practice, is difficult. For this issue, we propose a new concept of smart spectrum access (SSA) where useful information related to PU spectrum utilization is used to achieve not only the above requirements but also more efficient spectrum utilization. We also show an approach to realize practical SSA and it consists of a spectrum awareness system (SAS) and a dynamic spectrum access system (DSAS). The main role of the SAS is to provide useful information to the DSAS. The information can be obtained by the SAS through spectrum utilization measurement and analysis of the measurement data. In this paper, we present a framework for smart spectrum access and discuss the challenges of this approach. In addition, we report some of the experimental results related to SAS. 23497S-1-63190-055-6

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“…In channel occupancy rate (COR) measurements the purpose is to measure the availability of a channel(s) [4], [6], [7]. Usually in spectrum use measurements, the average DC is considered [1], [2].…”

Section: Introductionmentioning

confidence: 99%

“…Maximum based combining of DC values was recommended for COR estimation in [4]. The COR estimation can be also used to adapt CRS operating parameters to the current environment [6].…”

Section: Introductionmentioning

confidence: 99%

Duty Cycle and Channel Occupancy Rate Estimation with MED-FCME LAD ACC

Lehtomäki¹,

Vuohtoniemi²,

Umebayashi³

2012

Proceedings of the 7th International Conference on Cognitive Radio Oriented Wireless Networks

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Duty cycle (DC) and channel occupancy rate (COR) measurements are important to characterize the availability of white space for cognitive radio systems. To facilitate accurate DC measurements, we apply the localization algorithm based on double-thresholding (LAD) with the adjacent cluster combining (ACC). In order to get stable thresholds, we propose and apply a modified version of the LAD ACC called the MED-FCME LAD ACC. We show that LAD ACC based approaches can also be used for COR estimation. For even more accurate COR estimation, we propose estimation based on hard decision fusion of the frequency domain decisions. Measurement results confirm the good performance of the proposed approaches.

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Dynamic selection of CWmin in cognitive radio networks for protecting IEEE 802.11 primary users

Cited by 14 publications

References 10 publications

Duty cycle and noise floor estimation with Welch FFT for Spectrum Usage Measurements

Duty cycle and noise floor estimation with Welch FFT for Spectrum Usage Measurements

Development of a measurement system for spectrum awareness

Duty Cycle and Channel Occupancy Rate Estimation with MED-FCME LAD ACC

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