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    CHANNEL SWITCHING APPARATUS AND METHOD OF A BASE STATION AND CHANNEL SWITCHING APPARATUS AND METHOD OF A TERMINAL BASED ON THE COGNITIVE RADIO SYSTEM
    11.
    发明专利
    CHANNEL SWITCHING APPARATUS AND METHOD OF A BASE STATION AND CHANNEL SWITCHING APPARATUS AND METHOD OF A TERMINAL BASED ON THE COGNITIVE RADIO SYSTEM 未知

    公开(公告)号：CA2708838A1

    公开(公告)日：2009-06-25

    申请号：CA2708838

    申请日：2008-12-05

    Applicant: KOREA ELECTRONICS TELECOMM

    Inventor： KO GWANGZEEN ,  YOU SUNG-JIN ,  SONG MYUNG-SUN ,  HWANG SUNG-HYUN ,  UM JUNG-SUN ,  KIM CHANG-JOO

    IPC: H04B7/155

    Abstract: In a cognitive radio system, when communication in an operational channel is determined to be discontinued due to that an incumbent user (IU) entering the operational channel that is currently being used or due to that an excessive interference occurring in the operational channel, the operational channel is switched to a pre-arranged channel. However, since some parameters are different between the operational channel and the pre-arranged channel, an initialization procedure has to be performed to allow the cognitive radio system to be adapted to those some parameters. Since an initialization technique aiming for this situation is not developed yet, a conventional cognitive radio system uses a general initialization technique used to initially operate a system. However, the general initialization technique has to allow the system to be adapted to many parameters so that it takes a relatively long initialization time. A channel switching apparatus and method thereof of a base station, which allocates a slot for data exchange with each of a plurality of terminals in a frequency channel that is not used by the IU and thus performs communication, include transmitting a channel switching message for requesting to switch to a backup channel when a signal of the IU is sensed in the frequency channel; transmitting a beacon frame via the backup channel, wherein the beacon frame comprises allocation information about slots which are in the frequency channel and which are respectively allocated to each of the plurality of terminals; and allocating the slot for data exchange with each of the plurality of terminals to the backup channel according to the allocation information, and communicating with each of the plurality of terminals. By doing so, frequency resources between each of networks can be efficiently used, and convenience and efficiency with respect to network operation can be maximized.

    METHOD AND APPARATUS FOR CONTROLLING TRANSMIT POWER OF COGNITIVE RADIO DEVICE
    19.
    发明专利
    METHOD AND APPARATUS FOR CONTROLLING TRANSMIT POWER OF COGNITIVE RADIO DEVICE 未知

    公开(公告)号：CA2760269A1

    公开(公告)日：2010-11-04

    申请号：CA2760269

    申请日：2010-04-29

    Applicant: KOREA ELECTRONICS TELECOMM

    Inventor： HWANG SUNG-HYUN ,  KO GWANGZEEN ,  KIM CHANG-JOO ,  SONG MYUNG-SUN ,  UM JUNG-SUN ,  CHOI MIN-SHEO

    IPC: H04W52/00 ,  H04W52/04 ,  H04W52/34

    Abstract: The present invention relates to a transmission power control method and device. The transmission power control method for a cognitive radio device according to one embodiment of the present invention includes obtaining CR environmental information about a registered user or an unregistered user occupying an adjacent channel or an adjacent cell of a cognitive radio device, determining a transmission power value of the cognitive radio device using the CR environmental information, and generating transmission power control information including a transmission power value. According to the present invention, the reliable communication of the cognitive radio device can be guaranteed and at the same time interference for a registered user can be minimized.

    METHOD AND APPARATUS OF GENERATING SIGNALS FOR INITIAL RANGING IN OFDMA SYSTEM
    20.
    发明专利
    METHOD AND APPARATUS OF GENERATING SIGNALS FOR INITIAL RANGING IN OFDMA SYSTEM 未知

    公开(公告)号：CA2684306A1

    公开(公告)日：2008-10-30

    申请号：CA2684306

    申请日：2008-04-21

    Applicant: KOREA ELECTRONICS TELECOMM

    Inventor： SONG MYUNG-SUN ,  KIM CHANG-JOO ,  HWANG SUNG-HYUN ,  UM JUNG-SUN

    IPC: H04L27/26

    Abstract: Provided is a method and apparatus of generating signals for initial rang ing in an Orthogonal Frequency Division Multiple Access (OFDMA) system. The method, includes: generating a plurality of ranging symbols by cyclic-shifti ng sample data of a ranging symbol in one OFDMA symbol period as much as a v alue obtained by multiplying a cyclic prefix size by a symbol index; generat ing a ranging signal by copying a rear part corresponding to the cyclic pref ix size in the sample data with respect to each of the ranging symbols and i nserting the copied rear part in front of the sample data as a cyclic prefix .

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