Samsung Electronics Co., Ltd.

Seoul National University

Snu Rdb Foundation

Electronics and Telecommunications Research Institute

Hybee, Inc.

Yong-Hwan Lee

Seung-Hwan Lee

Sunghyun Choi

Keon-Wook Lee

Seung-hwan Lee

Hyeong-Jun Park

Min-Ho Cheong

Youngkyu Choi

Hyung-Sin Kim

Jin-Seok Han

Seung Hwan Lee

Jin-Woo Lee

June Moon

Sung-Geun Jin

Jae-hyuk Jang

Jae-Yun Ko

Jae Seok Bang

Jin Seok Han

Ji-woong Choi

Kwang-Hun Han

Young-Kyu Choi

Hyung Sin Kim

Byung-Hwan Kim

Kwanghun Han

Sunggeun Jin

O-Jin Kwon

Han-Jun Park

JaeYun Ko

Provided is data signal transmitting method and data signal receiving method in a wireless communication system. A method of transmitting and receiving data signal in a wireless communication system by changing a transmission speed and a payload size included in the data signal according to an operation environment is disclosed.

Data signal transmitting method and data signal receiving method in wireless communication system

Disclosed is a self-construction system of a wireless sensor network, and a method for self-construction of a wireless sensor network using the same. Also disclosed is a method for self-construction of a cluster tree structure-based wireless sensor network (WSN). The present invention can connect devices distributed densely in a wide area to a network while maintaining the advantages of a conventional tree-structured network, such as the reduction of time required for network construction, traffic by the exchange of control command messages, and a load for a routing path search, and thus can provide a WSN having an improved self-construction performance.

Self-construction system of wireless sensor network and method for self-construction of wireless sensor network using the same

The method for transmitting a signal while avoiding the influences of an interference signal in the same channel according to the present invention comprises: a process in which communication devices in the communication system perceive, in a distributed manner, whether or not an interference signal exists in a transmission channel being used; a process in which the communication devices in the communication system temporarily transceive signals using a plurality of available transmission channels other than the transmission channel currently being used so as to avoid an interference signal if the interference signal is perceived; and a process of determining the channel having a best link state as a transmission channel from among the plurality of used transmission channels and returning to an existing transmission system using a single channel.

Method for transmitting a signal while avoiding the influences of an interference signal existing in the same channel in a communication system having a main communication device and a plurality of terminal communication devices

An interference signal avoiding device of a frequency hopping spread system and a method thereof are disclosed. A method of transmitting/receiving an interference signal avoiding signal according to the present invention includes: determining a frequency hopping channel set and a parameter of an interference signal detector in consideration of characteristics of an interference signal; detecting whether there is an interference signal with respect to frequency hopping candidate channels that are to be used for the next frequency hopping by using the determined interference signal detector; transmitting a signal through a channel that is determined by the interference signal detector that there is no interference signal among the frequency hopping candidate channels; and searching a channel through which the signal is transmitted from the frequency hopping candidate channels in order to receive the transmitted signal.

Interference signal avoiding device of a frequency hopping spread system and method thereof

In a wireless communication system, at least one sounding subchannel determining parameter is transmitted from a sounding signal receiving apparatus to a sounding signal transmitting apparatus. A sounding subchannel for the sounding signal transmitting apparatus is allocated according to the sounding subchannel determining parameter. A sounding signal is received from the sounding signal transmitting apparatus over the allocated sounding subchannel. The sounding subchannel determining parameter is determined for allocating a sounding subchannel considering a frequency correlation.

Apparatus and method for transmitting and receiving sounding signal in a wireless communication system

A Tx beamforming method for multi-sector cooperative transmission in a multi-antenna system includes determining a transmission mode of sector boundary users according to a channel condition; determining a multi-sector cooperative Tx beam for supporting multiple users, based on the transmission mode of the user; determining a user combination for multi-sector cooperative beamforming by considering the determined multi-sector cooperative Tx beam; and performing sector cooperative Tx beamforming with the determined user combination. Thus, the overall system capacity can be enhanced.

Method and device for send beamforming and multiple user scheduling for multiple sector cooperative transmission in a multiple antenna system

The present invention relates to a transmission beamforming method and apparatus in an orthogonal frequency division multiplexing (OFDM)-based MIMO wireless system. In particular, the present invention relates to a transmission beamforming method in an OFDM-based MIMO wireless system and an apparatus therefor, wherein the transmission beamforming method comprises: estimating a channel from a received pilot signal and obtaining time for the estimating channel and 2D channel correlation information of a frequency band; obtaining estimated channel information based on the channel correlation information; obtaining differential information that represents a difference between the current channel and the estimated channel and quantizing the differential information; and generating a transmission beam weight by using a predefined code book from the quantized differential information. The present invention may also provide a method and apparatus for reducing the channel quantization error and feedback load by employing the OFDM-based MIMO in a wireless communication system using a transmission beamforming scheme, wherein a receiver estimates current channel information by using time and 2D channel correlation information of a frequency based on the previous channel information, compares the estimated current channel information with an actual channel and then feeds back the differential channel information, i.e., the difference between the estimated channel and the actual channel, to a transmitter.

Transmission beamforming method and apparatus in an orthogonal frequency division multiplexing-based MIMO wireless system

The invention relates to a method for channel estimation using a dedicated pilot signal in an OFDM-based communication system with multi-antenna transmission techniques. The receiver estimates the statistical characteristics of a virtual channel generated by beamforming by exploiting the statistical characteristics of common pilot channel, determines the optimum dedicated pilot pattern, and estimates the channel from dedicated pilot signal transmitted in an optimum pattern by means of AMMSE interpolation. The invention minimizes the channel estimation error by exploiting the statistical characteristics of the virtual channel, and optimally determines the dedicated pilot pattern according to the operation environment to maximize the transmission performance in terms of the pilot signaling overhead and the channel estimation error. In particular, the invention is very effective in low signal-to-interference plus noise power ratio (SINR) operation environments.

Method and apparatus for estimating channel using dedicated pilot signal in OFDM-based wireless communication system

A system and method for probing a channel by a base station in a communication system is provided. The channel probing includes performing pre-probing for selecting a subchannel, adjusting a subcarrier distance of a probing signal according to frequency selectivity indicative of frequency-domain channel selectivity based on a time channel correlation of each of a plurality of users and performing main-probing for transmitting the probing signal on the selected subchannel.

System and method for probing a channel in a communication system

An apparatus and method for partial adaptive transmission in a Multiple-Input Multiple-Output (MIMO) system are provided. The method includes estimating a correlation matrix between Transmit (Tx) antennas and an average Signal to Noise Ratio (SNR) and generating a long-term precoding matrix composed of a predetermined number of dominant eigen dimensions of the correlation matrix by using the estimated correlation matrix and average SNR. The apparatus and method provide a new adaptive MIMO transmission method capable of reducing the feedback information overhead and maximizing performance.

Apparatus and method for partial adaptive transmission in multiple-input multiple-output system

An UpLink (UL) scheduling method and apparatus considering a characteristic of a power amplifier in a mobile communication terminal are provided. The UL scheduling method includes calculating a packet transmission time, which minimizes energy consumed in packet transmission, by using a Direct Current (DC) voltage used in a power amplifier for signal amplification and by using nonlinear amplification efficiency; and scheduling UL data by using the calculated packet transmission time.

Apparatus and method for uplink scheduling considering characteristic of power amplifier in mobile communication terminal

An apparatus and method for avoiding interference in a broadband wireless communication system using FCS are provided. The apparatus and method include a receiver for monitoring channel statuses of neighbor cells using signals received from the neighbor cells, an active set generator for generating an active set according to at least one of the channel statuses of the neighbor cells, loads of the neighbor cells, and a performance gain from the neighbor cells, and a BS selector for selecting a serving cell from the active set according to the channel statuses of cells included in the active set. Accordingly, interference is reduced and reception performance is improved.

Apparatus and method for reducing other-cell interference in a broadband wireless communication system

A multicarrier communication system is provided that divides a full frequency band into a plurality of sub-carrier frequency bands, generates a plurality of segments having a frequency-time domain occupied by a predetermined number of sub-frequency bands and a predetermined number of time intervals, and classifies a plurality of segment types according to each of the segments, for data transmission. A mobile subscriber (MS) measures a channel state, extracts channel state information corresponding to the channel state, estimates a segment type using the extracted channel state information, and if there is a need for a change in the segment type, the MS transmits a segment type change request message to a base station (BS). Upon receiving a segment type change grant message from the BS, the MS receives data in a segment type corresponding to the received message.

System and method for transmitting/receiving data in a multicarrier communication system

An apparatus and method for uplink (UL) power control in a broadband wireless access (BWA) communication system are provided. In a communication method for a base station (BS), the channel gain, noise power and speed of each MS are determined, and the maximum allowable power of each mobile station (MS) are calculated using the determined channel gain, noise power and speed of each MS. Because the UL power is controlled according to the speed of the MS and the distance from the BS, the method can provide higher system capacity than the conventional power adaptation scheme.

Apparatus and method for performing uplink power control in broadband wireless access system

Disclosed is an apparatus and method for managing resources in a mobile communication system. The method includes classifying an overall frequency band into a plurality of segment types defined in time and frequency domains by considering a channel condition between a mobile station and the base station and a QoS level required by the mobile station, if data to be transmitted is data to be transmitted in real time, allocating the data to real-time type segments in such a manner as to satisfy a minimum QoS level for the data, and when there are real-time data remaining after allocating the data, and non-real-time type segments for allocating data to be transmitted in non-real time, diverting and allocating the real-time data to the non-real-time type segments.

Growing community of inventors

Seoul, South Korea

Yong-Hwan Lee