Electronics and Telecommunications Research Institute

Min-Ho Cheong

Sok-Kyu Lee

Hee-Jung Yu

Jong-Ee Oh

Seung-Chan Bang

Yu-Ro Lee

Hyeong-Jun Park

Yong-Hwan Lee

Chan-Ho Yoon

Hyun-Kyu Chung

Jee-Yon Choi

Jae-Woo Park

Young-Gyun Kim

A data transmission apparatus in a communication system includes a reception unit configured to receive terminal information from a plurality of terminals through a new frequency band for transmission and reception of data between the plurality of terminals and an AP (access point); a determination unit configured to determine access timing of the terminals to the AP by using the terminal information, and generate terminal access information including information on the access timing; and a transmission unit configured to transmit the terminal access information and beacon frames to the terminals, wherein the terminals access the AP and transmit data frames to the AP, at the access timing based on the beacon frames.

Apparatus and method for transmitting/receiving data in communication system

A data transmission apparatus in a communication system includes a verification unit configured to verify a basic frequency band capable of being used for transmitting and receiving data to and from a plurality of terminals, and a multi-bandwidth mode in the basic frequency band; a generation unit configured to generate data packets in the multi-bandwidth mode; and a transmission unit configured to transmit the data packets in the multi-bandwidth mode, wherein the multi-bandwidth mode includes a &#xbd;&#xd7; bandwidth of the basic frequency band, a basic bandwidth, a 2&#xd7; bandwidth of the basic frequency band, a 4&#xd7; bandwidth of the basic frequency band and an 8&#xd7; bandwidth of the basic frequency band.

A channel allocation apparatus in a communication system includes: a measuring unit configured to measure clear channel assessments (CCA) of a plurality of stations (STAs) included in the communication system; a checking unit configured to compare the measured CCAs to preset reference CCA, and check fairness and unfairness in the STAs; and an allocating unit configured to change and allocate channels allocated to STAs corresponding to unfairness, according to the measured CCA and the reference CCA.

Apparatus and method for allocating channel in communication system

A data transmission apparatus in a communication system includes a reception unit configured to receive terminal information from a plurality of terminals through a new frequency band for transmitting and receiving data between the plurality of terminals and one AP (access point); a verification unit configured to verify the terminal information, group the terminals into terminal groups by using the terminal information, and verify virtual APs which respectively correspond to the terminal groups, in the AP; and a transmission unit configured to transmit beacon frames in the virtual APs, to the terminals included in the terminal groups, wherein the beacon frames include beacon interval information, beacon duration information, beacon offset information, and terminal group information.

A channel allocation apparatus in a communication system includes: a receiving unit configured to receive terminal information containing transmission mode information of a plurality of stations (STAs) from the STAs; a checking unit configured to check transmission modes of the STAs and check a frequency band available for the STAs; an allocating unit configured to allocate channels of an allocable frequency band in the available frequency band to the STAs, according to the transmission modes of the STAs; and a transmitting unit configured to transmit channel allocation information on the channels allocated to the STAs to the STAs.

A data transmission apparatus in a communication system includes a reception unit configured to receive adjacent terminal information from a plurality of terminals through a new frequency band for transmission and reception of data between the terminals and one AP (access point); a verification unit configured to identify positions of the terminals within a service coverage of the AP through the adjacent terminal information, group the terminals into terminal groups through position-based grouping, and verify transmission possible times to the AP, in terminals included in the terminal groups; and a transmission unit configured to transmit the transmission possible times to the terminals included in the terminal groups through beacon frames in the AP, wherein, as the transmission possible times for the terminal groups, different time intervals are allocated in a beacon interval of the beacon frames.

An apparatus for transmitting data in a communication system includes: a receiving unit configured to receive feedback information for each of a plurality of stations (STAB) in response to a control frame; an adjusting unit configured to adjust links of the STAB at frequency channels based on the feedback information, and set optimal links for the respective STAB; and a transmitting unit configured to transmit data to the STAB through the optimal links, wherein the feedback information comprises one or more of optimal stream number information, optimal modulation and coding scheme (MCS) information, optimal bandwidth information, average signal-to-noise ratio (SNR) information, space-time information, optimal space-time block coding (STBC) information, group ID information, coding type information, and FB Tx type information.

Apparatus and method for transmitting and receiving data in communication system

A resource allocation apparatus in a communication system includes an identification unit configured to identify a new frequency band for transmission and reception of data between a plurality of terminals and a first access point, and identify a first frequency band which is being used by a second access point in the new frequency band; a setting unit configured to divide the new frequency band into sub bands of a basic frequency band, and set priorities of the sub bands; and an allocation unit configured to allocate the sub bands in correspondence to the priorities, for transmission and reception of data between the plurality of terminals and the first access point.

Apparatus and method for allocating resource 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.

There is provided to a method for encoding an LDPC (Low Density Parity Check) code using the result of checking a previously specified parity, including the steps of: forming a parity bit check matrix having a dual diagonal structure consisting of (N-K) rows for check nodes and (N-K) columns on the basis of the H matrix; calculating the values of all the parity bits by inserting a given binary value in sub-blocks, with the parity bit check matrix formed on the H matrix; if the values of the parity bits are incorrect, checking the parity bit corresponding to the sub-block located in the last part of the H matrix; searching the parity bit parts where the parity bit check result is represented as '1'; performing an XOR operation in sub-blocks on the parity bit part obtained through a simultaneous equation between the parity bits of the searched parity bit parts and the parity bit parts; and determining the value of the parity bit satisfying the condition that the value obtained by multiplying the H matrix by a code word vector.

Method for encoding low density parity check codes using result of checking previously specified parity bits

Provided are an apparatus for receiving signals in an OFDM communication system using multiple transmission/reception antennas and a method thereof. The method includes modulating a predetermined part of a data stream based on a multi-dimensional reception procedure to generate a first modulated data stream; regenerating a symbol corresponding to the modulated data stream; eliminating the regenerated symbol from a remained data stream; modulating the eliminated data stream to generate a second modulated data stream; and outputting an output signal obtained by serializing the first modulated data stream and the second modulated data stream.

Apparatus for receiving signals in OFDM communication system having multiple antennas and method thereof

In a method of canceling crosstalk signals, decoding or precoding through a diagonal channel analysis of the user domain and the time domain is performed, in addition to decoding or precoding in the user and time domains.

Method and apparatus for cancellation of cross-talk signals using multi-dimensional coordination and vectored transmission

The present invention is related to a partially overlapped single-carrier crosstalk signal cancellation method and an apparatus using the same. For this purpose, the present invention provides a crosstalk canceller including a pre-processor for frequency down-shifting an input signal, a crosstalk signal cancellation module for canceling the crosstalk signal by dividing the input signal by an interpolation ratio, a post-processor for converting an output of the crosstalk signal cancellation modulation into a passband signal, and an error feedback processor for performing a decimation operation on a residual crosstalk signal and feeding backing the decimated residual crosstalk signal to the crosstalk signal cancellation module. In addition, the present invention provides a crosstalk signal cancellation method for performing interpolation and filtering operations by frequency down-shifting an input signal including a crosstalk signal to a baseband and decimating a residual crosstalk signal by frequency-shifting to an original signal frequency.

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Daejeon, South Korea

Min-Ho Cheong