Spectral Efficiency of WRAN Spectrum Overlay in the TV White Space

Leem, Cha Sik; Kim, Sang Won; Kim, Chang Joo; seungsik, kang; Lee, Jaiyong

doi:10.4218/etrij.08.0208.0204

Cited by 6 publications

(3 citation statements)

References 2 publications

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“…In Leem et al [15] investigated the spectral efficiency of IEEE 802.22 WRAN spectrum overlay when it is used in TV white space. The WRAN system makes use of TV white space in the frequency ranges from 42 to 862 MHz in an opportunistic way but depends on the radio regulations of the country for the WRAN service.…”

Section: Related Workmentioning

confidence: 99%

Uplink Capacity Enhancement in IEEE 802.22 Using Modified Duplex Approach

Karthipan¹,

Vishvaksenan²,

Kalidoss³

et al. 2015

Wireless Pers Commun

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Efficient usage of spectrum is highly needed for wireless communication application. Cognitive radio (CR) is capable of using unused spectrum at any time/location by without causing any interference to neighbour. IEEE 802.22 wireless regional area network (WRAN) standard operation principles are based on CR technology and it follows time division duplex/Orthogonal frequency division multiplex as a multiple access scheme. Main problem with these access schemes are large turnaround time or idle time exist in the network. Due to the presence of large turnaround time in a network, severe cross time slot interferences and throughput inefficiency are observed in WRAN network. To combat this effect, modified duplex schemes are developed in this article. From the simulation results, it is observed that proposed technique considerably reduces idle time of the network, and additional data are transmitted through available elapsed time. Hence overall system throughputs are improved in the proposed system.

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Section: Related Workmentioning

confidence: 99%

Uplink Capacity Enhancement in IEEE 802.22 Using Modified Duplex Approach

Karthipan¹,

Vishvaksenan²,

Kalidoss³

et al. 2015

Wireless Pers Commun

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“…In IEEE 802.22-WRAN systems, the transmit power of BSs may go up to 100 W, but CPE uses 4 W; therefore, the transmit power of BSs will be set between 4 and 100 W [33]. In our system model, each BS and MTs may consume less transmit power, because the coverage of cellular systems is much smaller than WRAN systems.…”

Section: Boundary Conditionmentioning

confidence: 99%

Opportunistic Access of TV Spectrum Using Cognitive-Radio-Enabled Cellular Networks

Choi

Shin

2011

IEEE Trans. Veh. Technol.

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Abstract-Motivated by the Federal Communications Commission's recent approval of commercial unlicensed operations of some television (TV) spectrum, we propose to integrate cognitive radios (CRs) that operate on unoccupied TV bands with an existing cellular network to increase bandwidth for mobile users. The existing cellular infrastructure is used to enable the operation of such CRs. Because base stations (BSs) can sense spectrum and exchange the sensed information for the reliable detection of primary users (PUs) and white spaces, we propose a collaborative sensing mechanism based on cell topology, where the BS declares its cell to be PU-free when neither the BS nor its neighboring BSs detect any PU. This way, in a PU-free cell, the following two types of channels are available: 1) channels that are originally licensed for the cellular system and 2) CR channels that are discovered through spectrum sensing. Because the CR channels that operate on TV bands usually suffer less path loss than the cellular channels, we derive two important results. First, each user gains more capacity when accessing a cellular channel than an empty TV channel, as long as intercell interferences are caused by the same sources. Second, assigning TV bands to cell-edge users is better in maximizing cell capacity. These two effects and the performance of the proposed sensing mechanism are verified through numerical evaluation.

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“…But there are also disadvantages, for example, spectrum resources cannot meet the needs of users. As the demand for spectrum resource increases rapidly (e.g., [1][2][3]), there are increasingly more challenges and complications yet ironed out. For example, the application of a large portion of the assigned wireless spectrum is uneven [4], leading to underutilization of a significant amount of spectrum.…”

Section: Introductionmentioning

confidence: 99%