Electronics and Telecommunications Research Institute

Samsung Electronics Co., Ltd.

Kt Corporation

Sk Telecom Company, Ltd.

Hanaro Telecom., Inc.

Hyun-jae Kim

Sung Cheol Chang

Chul Sik Yoon

Kwang Jae Lim

Sung Kyung Kim

Won-Ik Kim

DongSeung Kwon

Wooram Shin

Jee Hwan Ahn

Anseok Lee

Jihyung Kim

Young-il Kim

Jung Hyun Kim

Eunkyung Kim

Kyung Soo Kim

Dong Seung Kwon

Keun Young Kim

Jae Sun Cha

Juhee Kim

Jung-Hoon Oh

Yong Su Lee

Young-II Kim

Ki-Seok Kim

Young-Jin Moon

A beamforming apparatus and method for expanding coverage of a control channel are provided, by which neighboring communication devices are classified according to the number of beams that they can receive, and therefore the frequency or period of beam transmission is adjusted to transmit a control channel by a beamforming method. Hence, an overhead reduction and an increase in transmission rate can be achieved, and coverage holes can be prevented.

Method and apparatus for beamforming in wireless communication system

A synchronization group management apparatus of a node recognizes a node belonging to a different group if groups having mobility are moved and located in the same area, and performs an operation of merging the different groups into one group by changing the frame start time and the synchronization reference time of the node.

Method and apparatus for managing synchronization groups in wireless communication system

In a wireless communication system formed of a plurality of nodes, an arbitrary node receives messages broadcasted from neighbor nodes and calculates amounts of changes in receiving times that are differences between receiving times when the messages are currently received and receiving times when the messages are previously received with respect to the neighbor nodes. The node corrects reference time thereof based on the amounts of changes calculated with respect to the neighbor nodes.

Method and apparatus for correcting reference time for distributed time synchronization

A method and apparatus for synchronizing a carrier frequency of a node included in a distributed network are provided. The apparatus includes a frequency offset estimating unit, an offset average value calculating unit, and a frequency adjustment value calculating unit. The method includes receiving preambles from a plurality of nodes adjacent to the node, estimating offsets of the carrier frequencies from the received preambles for each of the plurality of neighbor nodes, calculating an average value of the estimated offsets, calculating an adjustment value of the carrier frequencies with respect to the entirety of the plurality of neighbor nodes by using the average value, and adjusting a carrier frequency of the node on the basis of the adjustment value.

Method of frequency synchronization in distributed network

A method of setting a cycle of a low-duty mode in a femto base station is provided. The cycle of the low-duty mode has a pattern in which an available interval and an unavailable interval repeatedly appear, and the available interval is set to include a paging listening interval of a paging cycle. A method of setting a cycle of a low-duty mode in a femto base station having a service area overlapping with that of a macrocell is provided. An unavailable interval is set by taking the overlapping degree of the service area of the femto base station with the macrocell into consideration. A method of setting a cycle of a low-duty mode in a plurality of femto base stations operated in the low-duty mode is provided. The same cycle can be set for a plurality of base stations.

Method of low-duty mode operation of femtocell base station

If a target node that enters into a transmission range is sensed, a mesh node of a wireless communication system selects an agent node having itself and a target node as a neighboring node among a plurality of neighboring nodes to form a link with the target node through the agent node. Also, the mesh node deletes the formed link if a target node that is out of a transmission range among a plurality of neighboring nodes is sensed, and forms a substitution path for at least a portion among an entire path of a connection including the deleted link.

Method and apparatus for managing wireless network

A multi-carriers management device of a communication system supporting multi-carriers requests a terminal attempting to enter a sleep window to change a primary carrier, and transmits a control message to the terminal through the changed primary carrier during the sleep window.

Multi-carriers managing device and method and sleep mode operating method of terminal

A method for managing radio resources of a base station is provided. The method includes evaluating a radio environment between a base station and at least one neighboring base station or a radio environment between the base station and terminals connected to the base station, if the evaluated radio environment does not meet predetermined criteria, selecting a new radio resource, deactivating the existing radio resource, and reactivating the new radio resource. Accordingly, the radio resources can be efficiently managed.

Apparatus for managing radio resources of base station and method for managing the same

In an orthogonal frequency division multiple access (OFDMA)-based wireless mesh network, a communication node receives information regarding a next transmission time of a 1-hop node and a 2-hop node through the 1-hop node, calculates next transmission intervals of the 1-hop node and the 2-hop node, determines a next transmission time of the communication node by using the next transmission intervals of the 1-hop node and the 2-hop node, and then transmits, to an 1-hop node of the communication node, the information of the next transmission time together with the information of the transmission time of the 1-hop node, received from the 1-hop node.

Method and apparatus for access control in wireless communication system

A base station management method according to the present invention is a method for managing an operation mode of a base station, and includes determining whether a terminal exists in a cell managed by the base station and operating in a low duty operation mode (LDM) when no terminal exists in the cell.

Device and method for managing base station and terminal

A method and apparatus for measuring a radio environment of a base station is provided. The method includes respectively selecting one or more frames for measuring a radio environment in a first mode in which an Over-The-Air Receiver (OTAR) of the base station is initialized and a second mode in which the OTAR is active, continuously measuring the radio environment based on the selected one or more frames in the first mode and intermittently measuring the radio environment based on the selected one or more frames in the second mode.

Apparatus for measuring radio environment of base station and method for measuring the same

A method for controlling interference between a plurality of neighboring base stations for a terminal by a serving base station of the terminal in a communication system is provided. The method includes receiving interference amount information on a first region of a downlink frame from the terminal, determining an interference amount estimate for the first region based on the received interference amount information, comparing the determined interference amount estimate with an interference amount tolerance for the first region; and transmitting an interference indicator requesting reduction in transmission power for the first region to the plurality of neighboring base stations when the interference amount estimate exceeds the interference amount tolerance.

Method for controlling interference

A method and apparatus for controlling power for uplink are provided. When a base station is moving or unable to communicate with others, at least one interference amount is estimated for a neighboring base station based on a path gain between a terminal and the neighboring base station and a transmission power of each encoding packet size and transmission format included in a candidate group related to scheduling transmission power parameters. A target interference amount is determined based on an interference amount control value and an initial target interference amount according to a processing load of a serving base station, and one interference amount is selected from estimated interference amounts based on the target interference amount. The terminal determines the transmission power based on an encoding packet size and a transmission format corresponding to the selected interference amount.

Method and apparatus for controlling power for uplink

The present invention relates to an apparatus and method for variable fast Fourier transform. According to an embodiment of the present invention, two n-point fast Fourier transform (FFT) processors are used to generate two n-point FFT output data or one 2n-point FFT output data. The one 2n-point input data is alternately input to the two n-point FFT processors. Each of the two n-point FFT processors selects a twiddle factor for the n-point input data or the 2n-point input data and performs fast Fourier transform. A butterfly operation is performed on signals obtained by performing fast Fourier transform on the 2n-point input data signal, and the processed signals are aligned in an output order. According to this structure, it is possible to realize a fast Fourier transform hardware engine that selectively performs multi-frequency allocation in a base station system that supports the multi-frequency allocation.

Apparatus and method for variable fast fourier transform

A method for controlling transmission power in a mobile communication system is provided. According to the method, a serving base station arranges a plurality of terminals in ascending order according to Carrier-to-Interference-and-Noise-Ratios (CINRs) based on the CINR measured by the plurality of terminals, classifies the plurality of terminals in one of a first group and a second group according to the order, allocates a subchannel of a data region corresponding to the first group from among a plurality of data regions included in the uplink frame to a terminal classified as the first group, and allocates a subchannel of a data region corresponding to the second group from among the data regions to a terminal classified as the second group.

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Incheon, South Korea

Hyun-jae Kim