Electronics and Telecommunications Research Institute

Jee-Yon Choi

Sok-Kyu Lee

Yoo-Seung Song

Jong-Ee Oh

Yun-Joo Kim

Hyun-Gu Park

Hyun-Kyu Chung

Jae-Seung Lee

Jong-Hyun Lee

Jin-Young Lee

Minho Cheong

Byung-Sun Lee

Hyungu Park

Min-Ho Cheong

Seong-Soon Joo

Jae-Woo Park

Hyun-Ha Hong

Young-Sik Chung

Tae-Joon Park

Kwhang-Hyun Ryu

Jong-Tae Song

Yunjoo Kim

Jeong-Dong Ryoo

Kyung-Pyo Jun

Kyounghee Song

Bong-Wan Kim

Hae-Geun Kim

Disclosed are an apparatus and a method for transmitting/receiving data by acquiring channel information of a terminal receiving data in a communication system providing services to users through beamforming according to a multi-input multi-output (MIMO) scheme, wherein so as to acquire channel information of the terminal for transmitting/receiving data through the beamforming according to the MIMO scheme, a null data packet announcement (NDPA) frame and a null data packet (NDP) frame are transmitted to the terminal, the beamforming frame is received from the terminal as a response of the null data packet announcement frame and the null data packet frame, and the channel information of the terminal included in the beamforming frame and the indication information on which the null data packet frame included in a control information field of the beamforming frame is normally received are checked.

Apparatus and method for transmitting/receiving data in communication system

Disclosed is an apparatus and method for transmitting/receiving data using a low-density parity check (LDPC) coding scheme in a communication system. The method includes generating a multi-user data packet containing data to be transmitted to a plurality of users, encoding the multi-user data packet as a BCC and an LDPC code, and transmitting the encoded multi-user data packet to the plurality of users. In the method, the encoding of the multi-user data packet encodes MPDU subframes corresponding to each of the plurality of users in the multi-user data packet as the LDPC code, and calculates information on a length in LDPC encoding, corresponding to the encoding of the multi-user data packet as the LDPC code.

Provided are an apparatus and method for transmitting data using a multi-antenna. The apparatus includes a transmission buffer selecting unit for selecting transmission buffer of an antenna group corresponding to characteristics of each aggregated Medium access control Protocol Data Units (MPDU) when a list of aggregated MPDUs to transmit is received; a data transmitting unit for generating a list of aggregated MPDUs to transmit with storage information of the aggregated MPDUs, transferring the generated list to the transmission buffer selecting unit and transmitting corresponding aggregated MPDUs through the selected transmission buffer; and a timing controlling unit for controlling a transmission timing of each aggregated MPDU.

Apparatus and method for transmitting data using multi-antenna

Provided are an apparatus and method for processing an ARQ in a MIMO system. The apparatus includes a storing unit for storing reordering thresholds of each receiving terminal and retransmission data; a priority managing unit for assigning a priority to a plurality of antenna groups in ascending order of a bit error rate of a wireless channel of each antenna group and managing the plurality of antenna groups based on the priorities; a data transmitting unit for transmitting retransmission data; and a controlling unit for controlling the data transmitting unit to transmit retransmission data within a range not exceeding a reordering threshold of a corresponding receiving terminal sequentially using an antenna group having the highest priority first.

Apparatus and method for processing auto repeat request in multiple input multiple output system

Provided are a MAC method and a method for transmitting data using the same in a WLAN. The MAC method includes: transmitting a bandwidth scheduling report frame for informing information on downlinks and uplinks allocated to a terminal by including the bandwidth scheduling report frame in one of the downlinks where the bandwidth scheduling report frame includes a plurality of downlinks, a plurality of uplinks, and a plurality of short uplinks and the number of the plurality of downlinks is equal to the number of the plurality of uplinks; receiving a bandwidth request frame for requesting bandwidth allocation through one of the uplinks; and allocating a bandwidth to each of the terminals by an unit of the downlink and the uplink.

Medium access control method and data transmission method using the same in wireless local area network

Provided is a method for forming a customized-quality integrated transport network based on synch and asynch frames, and a transport network forming apparatus thereof. The method of the present invention includes: a) synchronizing a transmission bit rate in a network; b) when the transmission bit rate is synchronized in the network and a connection request is received, establishing a connection by determining a route and a start cycle time of the link based on a quality of the connection request and transporting it to nodes of the link; and c) transmitting data to be transported to a link of an adjacent node within the virtual cycle time when the data are synch frames; or when the data are asynch frames and the data are not transmitted within a virtual cycle time of a link to be switched, keeping the data waiting for a next cycle time.

Method and apparatus for constituting transport network based on integrated synch and asynch frame

There are provided an apparatus and method for recovering a clock signal from a burst mode signal. A first delay delays an input data signal for half of a time period of the input data signal, and produces a first delay signal. An XOR gate adds the input data signal and the first delay signal provided from the first delay, and provides an inverted signal of the added signal. An OR gate adds an output signal of the XOR gate and a second delay signal, and provides the added signal as a recovered clock signal. A second delay delays the added signal provided from the OR gate for an integer multiple of a time period of the input data signal, and produces the second delay signal that is provided to the OR gate. The frequency of the recovered clock signal is not limited by any delay in the gate elements due to a phase transition of the input data signal occurring when every other packet is provided.

Apparatus and method for recovering clock signal from burst mode signal

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Daejeon, South Korea

Jee-Yon Choi