Electronics and Telecommunications Research Institute

Samsung Electronics Co., Ltd.

Kt Corporation

Sk Telecom Company, Ltd.

Hanaro Telecom., Inc.

Ktfreetel Co., Ltd

Sk Telecom Ltd.

Hanaro Technologies, Inc.

Hanare Telecom, Inc.

Youn-Ok Park

Jun-Woo Kim

Kyung-Yeol Sohn

Chang-Wahn Yu

Young-Ha Lee

Young-Jo Bang

Dae-Ho Kim

Hyeong-Sook Park

Yong-Su Lee

Su-Chang Chae

Seung Jae Bahng

Young-Hoon Kim

Eon-Young Hong

Seung-Jae Bahng

Jae-Gun Jung

Seung-Ku Hwang

Young Ha Lee

Hoon Do Heo

Dae Ho Kim

Young Jo Bang

Chang Wahn Yu

Jung Pil Choi

Jae Kwon Kim

Jung-Pil Choi

Hyun Myung Wu

Seung-Chan Bang

Hoon Ki Lee

Dong-Seung Kwon

Jee-Hwan Ahn

Kyung Yeol Sohn

Hyeong Sook Park

Sook-Jin Lee

Eon Young Hong

Hyung Rae Park

Young-Jin Moon

Yong-Seouk Choi

Young Ho Yun

Eui-Hoon Jeong

Se-Young Cho

Ik-Soo Jin

Ii Min Kim

An intelligent multiple access communication (MAC) control apparatus and method are disclosed. The intelligent MAC control apparatus includes a connection control unit, a resource management unit, a session control unit, a flow control unit, and a determination unit. The connection control unit connects at least one Radio Access Technology (RAT) and a wireless network. The resource management unit collects RAT information including information about available resources and radio state of the RAT. The session control unit checks the QoS of at least one connection target service. The flow control unit determines the priority of the connection target service, and selects a preferential connection target service. The determination unit determines a connection RAT for performing the preferential connection target service based on the QoS and the RAT information.

Intelligent multiple access communication control apparatus and method

A central office node using beam patterns and antenna polarizations, a remote node, and a wireless communication method between the nodes. The central office node includes: a first antenna array with first polarization attributes; a second antenna array with second polarization attributes; and a transmitter unit configured to transmit data to a plurality of remote nodes using beam patterns generated during beamforming and the polarization of the first and second antenna arrays.

Central node apparatus and method for transmitting wireless signals between central office node and remote node using beam patterns and antenna polarization

Provided are a preamble transmission device of a multi-mode supporting base station and a preamble detecting device of a multi-mode supporting user terminal. Selecting of the preamble signal is driven by the user terminal capable of supporting multi-modes, which contributes to smooth services from a user's viewpoint, and to effective use of the limited radio resources from an operator's viewpoint.

Preamble transmission device of multi-mode supporting base station and preamble detecting device of multi-mode supporting user terminal

There are provided a method of generating a ranging signal of a wireless terminal and a device for generating a ranging signal of a wireless communication system that can generate the ranging signal using one IFFT engine independently from a mode of the ranging signal transmitted in uplink in a wireless communication system in which a frequency interval of subcarriers used to generate an initial ranging signal and a frequency interval of subcarriers using periodic ranging are different. In this way, it is possible to decrease complexity of hardware and design of the wireless terminal, and decrease power consumption of the wireless terminal through hardware simplification.

Device for generating ranging signal of wireless communication system and method of generating ranging signal of wireless terminal

Provided are a device and method for estimating carrier frequency offset of OFDM signals transmitted and received through a plurality of polarized antennas that may accurately estimate carrier frequency offset used for carrier frequency synchronization acquisition when there is interference between polarized waves.

Device and method for estimating carrier frequency offset of OFDM signals transmitted and received through plurality of polarized antennas

The present invention relates to a signal transmitting apparatus, a method thereof, and an inverse fast Fourier transform (IFFT) apparatus for a signal transmitting apparatus. A signal transmitting apparatus according to an embodiment of the present invention receives data, and performs inverse fast Fourier transform (IFFT) on the data on the basis of a twiddle factor for shifting output data by the size of a cyclic prefix. In addition, the signal transmitting apparatus sequentially stores data corresponding to the size of the cyclic prefix starting with initial data among the transformed data, and generates an OFDM symbol on the basis of the stored data and the transformed data. According to the embodiment of the present invention, it is possible to efficiently reduce a time delay and a memory use amount when a cyclic prefix is added at a transmitting end, without changing the size of hardware and power consumption.

Signal transmitting apparatus, method thereof, and inverse fast fourier transform apparatus for signal transmitting apparatus

When a base station of a time division duplex based mobile communication system receives an initial ranging request signal from a subscriber station, the base station generates initial ranging information including delay time information to the subscriber station, and receives uplink data delayed and transmitted using a delay time from the subscriber station. Also, when the subscriber station transmits an initial ranging request signal to the base station and receives initial ranging information including delay time information from the base station, the subscriber station establishes a transmission parameter value by using the transmission parameter value included in the initial ranging information and transmits uplink data by using the established delay time.

Method and apparatus for uplink timing synchronization with ranging signal in mobile communication system

Disclosed are a row-vector norm comparison method and a row-vector norm comparison apparatus for an inverse matrix. A row-vector norm comparison apparatus includes: an input matrix processing module that receives and combines constituent elements of a matrix; a cofactor operation module that multiplexes the combination result of the constituent elements to calculate factors constituting an adjoint matrix; a square calculation module that squares the calculated factors; a summation module that selects a predetermined number of factors among the squared factors and sums the selected factors to calculate the norms of row vectors in an inverse matrix; and a norm comparison module that outputs a comparison result of the calculated norms of the row vectors. A row-vector norm comparison method includes: combining constituent elements of a matrix to generates a plurality of combination results of the constituent elements; multiplexing the combination results to calculate factors constituting an adjoint matrix of the matrix; squaring the calculated factors and selectively summing the squared factors; and calculating the norms of row vectors in an inverse matrix and comparing the calculated norms of the row vectors. With this configuration, row-vector norm comparison for an inverse matrix can be performed with a design structure. Therefore, it is not necessary to use an existing complex operation method. In addition, low power consumption of the multiple antenna system can be achieved, and efficiency of the design structure can be improved.

Row-vector norm comparison method and row-vector norm comparison apparatus for inverse matrix

The present invention relates to a digital clipping method for reducing a high peak-to-average power ratio (PAPR) of a transmission signal in a transmitter of an orthogonal frequency division multiplexing access (OFDMA) system. In the method, a) the transmission signal to be digitally clipped is divided into real and imaginary parts, b) magnitudes of the real and imaginary part signals are divided into a plurality clipping levels, and c) the transmission signal is respectively clipped by comparing the real and imaginary part signals with the plurality of clipping levels while allowing phase errors. In c), a plurality of comparators is used to respectively compare the real and imaginary parts of the complex number transmission signal with the plurality of clipping levels.

Digital clipping method for a transmitter of an orthogonal frequency division multiple access system

Disclosed is a device and method for compensating for phase distortions in a base station of an OFDMA-based cellular system. The method comprises receiving OFDM symbols from a plurality of mobile stations, canceling a symbol guard interval using a reference timing signal, and performing an FFT (fast Fourier transform) process on the OFDM symbols; dividing the OFDM symbols that have undergone FFT processing into subchannel groups of the mobile stations; restoring phases of the OFDM symbols divided into subchannel groups; and performing channel estimation and equalization on the restored OFDM symbols for each mobile station to thereby perform a demodulation process.

Device and method for compensating for phase distortion in base station of OFDMA-based cellular system

The present invention relates to an apparatus and method of estimating a channel based on a channel delay spread in a mobile communication system. Pilot subcarriers are inserted between data subcarriers at predetermined intervals to estimate a channel at locations of the pilot subcarriers. An approximate channel delay spread value is estimated by using an autocorrelation value of a pilot signal. Then, a channel for data subcarriers between the pilot subcarriers is estimated by using a Wiener finite impulse response (FIR) filter that has a separate coefficient according to the estimated delay spread value. Accordingly, by changing the Wiener FIR filter coefficient according to the delay spread value of the channel, it is possible to estimate the channel so as to be adaptive for a change of the channel over time. Since the filter coefficients, which are calculated in advance, are used, it is possible to reduce the amount of calculation required when calculating the filter coefficients. As a result, an apparatus for estimating a channel can be easily achieved.

Apparatus and method of estimating channel based on channel delay spread in mobile communication system

Disclosed herein is a base station that extracts a ranging channel signal from a received signal partially correlates each of a plurality of ranging channel signals and each of ranging codes according to ranging modes, and selects a ranging channel signal greater than a first threshold value, the plurality of ranging channel signals being signals according to plurality of time delays of a ranging channel signal. In addition, the base station correlates each of the selected ranging channel signal and each of corresponding ranging code, selects a ranging channel signal having the maximum correlation value, and estimates receiving power by using a time delay corresponding to the selected ranging channel signal.

Apparatus and method for processing ranging channel of communication system

The present invention relates to a low density parity check (LDPC) encoding method and an apparatus thereof. In the LDPC encoding method, a matrix multiplication corresponding to ETand Tis eliminated according to a structural characteristic in an encoding process. Accordingly, shift weights that are not &#x2212;1 among shift weights corresponding to partial blocks A, B, and C of a parity check matrix are used to perform an encoding operation, and a cyclic shift operation of an information unit block is performed in parallel so that a first parity block and a second parity block may be simultaneously generated.

Parity check matrix storing method, block LDPC coding method, and apparatus using parity check matrix storing method

In a signal monitoring apparatus of a base station of a communication system having multiple antennas, a transmitting/receiving unit transmits a plurality of transmit signals by using the multiple antennas or processes a plurality of receive signals received through the multiple antennas. A radio frequency calibration unit calibrates the transmit signals transmitted through the multiple antennas, and processes at least one target transmit signal among the plurality of transmit signals so as to monitor the at least one target transmit signal. A signal monitoring unit receives at least one first signal or at least one second signal, and transmits the at least one first signal or the at least one second signal to user equipment. The at least one first signal is a signal processed from at least one target receive signal among the plurality of receive signals, and the at least one second signal is a signal processed from the at least one target transmit signal by controlling the radio frequency calibration unit.

Apparatus and method for monitoring base station signal in communication system having multiple antennas

An apparatus and method for canceling a DC offset efficiently removes the DC offset by calculating the DC offset after acquiring synchronization in a terminal receiver used for an orthogonal frequency division multiplexing system. The apparatus for canceling the DC offset includes an adding/averaging unit (), an accumulator (), a synchronization determiner (), and a pulse density modulation signal generator (). The adding and averaging the added input data signals over one frame. The accumulator () outputs a DC offset control value by successively accumulating the DX offsets calculated from the adding and averaging unit. The synchronization determiner () determines whether to output the DC offset control value provided by the accumulator () based on synchronization information. The pulse density modulation signal generator () generates a digital pulse density modulation signal based on a representative value provided by the synchronization determiner ().

Apparatus for cancelling DC offset and method thereof

Growing community of inventors

Daejeon, South Korea

Youn-Ok Park