• Title/Summary/Keyword: 라이선스 주파수 대역

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An Analysis on Channel Sensing Overhead in IEEE 802.22 Cognitive Radio Networks (IEEE 802.22 인지 라디오 네트워크에서 채널 센싱 오버헤드 분석)

  • Park, Keun-Mo;Kim, Chong-Kwon
    • Journal of KIISE:Information Networking
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    • v.37 no.3
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    • pp.249-253
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    • 2010
  • Resource of wireless frequency bandwidth is gradually going to be deficient due to explosive increase of traffic and saturated non-licensed frequency band such as ISM. In the contrary, many licensed frequency bands are revealed to be low in utilization by several measurement based researches. To alleviate this inefficiency, a concept of cognitive radio is suggested. Cognitive radio lets non-licensed user exploit the licensed frequency band as long as non-licensed user does not interfere licensed user and as a result, it is possible to harness wireless frequency more efficiently. IEEE 802.22 is the first standard network with cognitive radio technology and it employs Two-Stage channel sensing mechanism to accomplish both enough licensed user protection and efficient channel utilization. In this paper, we analyze the overhead of Two-Stage channel sensing mechanism and identify the influence of channel sensing time to the overhead.

Active Secondary User Selection Algorithm of Opportunistic Spatial Orthogonalization Considering Interference by a Primary User (주 사용자의 간섭을 고려한 Opportunistic Spatial Orthogonalization의 활성 부 사용자 선택 알고리즘)

  • Yoo, Kang-Hyun;Kim, Yong-Hwa;Lee, Han-Byul;Kim, Seong-Cheol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.11A
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    • pp.892-902
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    • 2011
  • The opportunistic spatial orthogonalization (OSO) scheme, proposed by Cong Shen and Michael P. Fitz, allows the existence of secondary users during the period in which the primary user is occupying all licensed bands. This paper introduces an active secondary user selection algorithm which mitigates the interference from the primary user transmitter to the secondary user receiver based on single-input multi-output system without altering a primary user's transmission strategy. A proposed algorithm guarantees the minimum average throughput of the primary user and overcomes the average sum throughput of a conventional OSO. We have numerically analyzed the average throughput under various constraints.