Abstract:
A power control method of a TDD(Time Division Duplex) communication system and a device thereof are provided to offer an excellent-performance power control method without requiring a separate feedback value, with regards to noncontinuous uplink channels that many users temporally separate and occupy one channel, thereby supporting noncontinuous uplink users. Uplink power determiners(1115,1116) determine uplink power values by using the quantity of external cell interference received from a base station, power control calculation factors of the current frame obtained by using power increase/decrease variation estimated through downlink, and power control calculation factors of a previous frame. An uplink power controller(1117) transmits the uplink power values to a transmitter to control uplink power.
Abstract:
PURPOSE: An apparatus and a method for transmitting a coexistence beacon protocol(CBP) packet in a recognition wireless communication system are provided to prevent the transmission collision of the CBP packet by transferring the CBP packet through different channels. CONSTITUTION: Priority is applied to each channel by referring the channel state of wireless regional area networks. Based on the priority, the satisfactory state of a quality of service(QOS) with respect to a CBP packet is successively determined. A channel(201) with a first priority among channels satisfying the QOS is selected as a channel for the transmission of the CBP packet. The CPB packet is transmitted through the selected channel.
Abstract:
PURPOSE: An apparatus and a method for transmitting a coexistence beacon protocol packet in a cognitive wireless communication system are provided to determine a WRAN(Wireless Regional Area Network) which will transmit a CBP packet through competition in a frequency shaft, thereby improving efficiency of CBP transmission without influence of transmission delay. CONSTITUTION: A CBP(Coexistence Beacon Protocol) transmitter generates a time random number and a frequency random number(303). If it is not an indication time of the time random number, the CBP transmitter confirms the reception of a competition beacon of another WRAN(Wireless Regional Area Network)(305,307). If the competition beacon of another WRAN is not received, the CBP transmitter confirms the termination of the first symbol interval of an SCW(Self-Coexistence Window) slot(309). If the competition beacon received through a sub channel does not exist, the CBP transmitter transmits a CBP packet(315,317).
Abstract:
PURPOSE: An apparatus and a method for requesting information on a channel condition in a wireless cognitive communication system are provided to use a database having band scheduling information of a system with a license, thereby exactly determining whether to use a channel. CONSTITUTION: A base station recognizes activation inside a cell of an apparatus(201). A DB server recognizes a change of radio resource scheduling information of the system with a license(207). The DB server re-calculates each EIRP Cap of apparatuses. The apparatuses are registered in a list. The recalculated EIRP Caps are sent to the base station(209). The base station recognizes EIRP calculation-related information of an apparatus inside a cell of the base station during communication according to the recalculated EIRP_Cap(211).
Abstract:
PURPOSE: A coexist beacon protocol packet transmission apparatus for communication information share between base stations in a CR-based OFDM(Orthogonal Frequency Division Multiplexing) access system and a method thereof are provided to reduce the collision probability of CBP packets. CONSTITUTION: A base station receives CBP(Coexistence Beacon Protocol) packets from neighboring base stations of neighboring cells through an SCW(Self-Coexistence Window) socket during a SCW_Active_Reception section(601), decodes a corresponding CBP packet, detects the CBP_ID of the received CBP packet(603). The base station generates CBP_ACK message. The CBP_ACK message includes a CBP_ID list of the received CBP packets. The base station transmits the CBP packets to the neighboring cells(605).
Abstract:
An apparatus and a method for obtaining a channel bandwidth in a wireless cognitive communication system are provided to use efficiently the channel bandwidth by performing a signal detection process in a data transceiver except for a channel sensing period in the wireless cognitive communication system. An apparatus for obtaining a channel bandwidth in a wireless cognitive communication system includes a bandwidth sensing unit(303), a sub-channel sorter(307), a signal detector(309), and a channel controller(305). The bandwidth sensing unit detects a first channel bandwidth to an entire bandwidth in a channel sensing period. The sub-channel sorter sorts signals of each sub-channel allocated to SOFDM(Scalable Orthogonal Frequency Division Multiplexing) in a data receiving process on the basis of the detected channel bandwidth. The signal detector detects signals of an adjacent sub-channel including the channel bandwidth until a next channel sensing period. The channel controller provides carrier frequency information for second channel bandwidth by reflecting a using state of each sub-channel.
Abstract:
An apparatus and a method for connecting a call in a communication system are provided to allow terminals in a call-connected state to perform a call connection at the same time for their communication. When the first terminal(420) detects that a call should be connected with the second terminal(430), it transmits a call connection request message for requesting a call connection to the second terminal, to an MSC(Mobile Switching Center)(411). When the second terminal detects that a call is connected with the first terminal, it transmits a call connection request message for requesting a call connection to the first terminal, to the MSC(413). The MSC selects the second terminal and transmits a call connection release request message for releasing a call connection request of the second terminal to the second terminal(415). The MSC transmits a call connection attempt message for a call connection request by the first terminal to the second terminal(417). When the first and second terminals are connected for a call, the call connection of the second terminal is released to allow the terminals to be connected for call communication(419).
Abstract:
A subchannel configuration method in a communication system is provided to be capable of grouping subchannels by considering data bursts having the same transmission characteristics, while time-hopping is performed for subcarriers within the grouped subchannels, thereby obtaining frequency diversity. Subchannels are allocated in block unit(602). The subchannels are grouped according to data bursts having the same transmission characteristics(604). Subcarriers are hopped to a time base within subchannel areas included in the group(606). The transmission characteristics refer to more than one of beamforming, MIMO(Multiple Input Multiple Output), and precoding methods.
Abstract:
본 발명은 제1주파수 대역과, 상기 제1주파수 대역을 포함하는 제2주파수 대역을 사용하는 주파수 오버레이 통신 시스템의 송신 장치에 있어서, 상기 제2주파수 대역은 상기 제2주파수 대역과 오버레이 되는 상기 제1주파수 대역과 상기 제1주파수 대역과는 상이한 제3주파수 대역을 포함하며, 프리앰블 채널 신호를 생성하는 프리앰블 채널 생성기와, 파일럿 채널 신호를 생성하는 파일럿 채널 생성기와, 트래픽 채널 신호를 생성하는 트래픽 채널 생성기와, 제어 채널 신호를 생성하는 제어 채널 생성기와, 전송할 데이터가 발생하면, 상기 데이터를 스케쥴링하여 상기 제2주파수 대역에 상응하게 데이터가 전송될 주파수 대역을 할당하는 스케쥴러와, 상기 할당한 주파수 대역에 상응하게 상기 프리앰블 채널 신호와, 파일럿 채널 신호와, 트래픽 채널 신호와, 제어 채널 신호를 다중화하여 다운링크 채널 신호로 생성하는 다중화기와, 상기 다운링크 채널 신호를 역고속 푸리에 변환하는 역고속 푸리에 변환기를 포함하며, 상기 프리앰블 채널 신호는 상기 제1주파수 대역을 통해 전송되는 제1프리앰블 채널 신호와, 상기 제3주파수 대역을 통해 전송되는 제2프리앰블 채널 신호를 포함하며, 상기 파일럿 채널 신호는 상기 제1주파수 대역을 통해 전송되는 제1파일럿 채널 신호와, 상기 제3주파수 대역을 통해 전송되는 제2파일럿 채널 신호를 포함하며, 상기 트래픽 채널 신호는 상기 제1주파수 대역을 통해 전송되는 제1트래픽 채널 신호와, 상기 제3주파수 대역을 통해 전송되는 제2트래픽 채널 신호를 포함하며, 상기 제어 채널 신호는 상기 제1주파수 대역을 통해 전송되는 제1제어 채널 신호와 상기 제3주파수 대역을 통해 전송되는 제2제어 채널 신호를 포함한다. 주파수 오버레이, NB 통신 시스템, EB 통신 시스템, 프레임 구조, 채널 구조
Abstract:
A priority-based scheduling system and method in a frequency overlay communication system are provided to be compatible with an existing communication system that uses a different central frequency band. The first MS(Mobile Station) uses the first frequency band. The second MS uses the second frequency band. The first MS requests a base station to allocate resources required for using the first frequency band. The second MS requests the base station to allocate resources required for using the first frequency band. The base station determines an amount of channel quality information which the first and second MSs will feed back in consideration of the first MS preferentially according to the amount of resources requested by the MSs, and informs the MSs of the decided result.