Electronics and Telecommunications Research Institute

Samsung Electronics Co., Ltd.

Kt Corporation

Hanaro Telecom., Inc.

Sk Telecom Company, Ltd.

Ktfreetel Co., Ltd

Sk Telecom Ltd.

Jun-Woo Kim

Youn-Ok Park

Youn Ok Park

Dae-Ho Kim

Hyeong-Sook Park

Kyung-Yeol Sohn

Young-Ha Lee

Kyung Yeol Sohn

Young Jo Bang

Chang Wahn Yu

Hyeong Sook Park

Eon Young Hong

Su-Chang Chae

Jae-Gun Jung

Young-Hoon Kim

Yong-Su Lee

Dae Ho Kim

Seung Jae Bahng

Seungjae Bahng

Jung Pil Choi

Young-Jo Bang

Jae Kwon Kim

Byung-Han Ryu

Hoon Ki Lee

Hoon Do Heo

Jee Hwan Ahn

Seung-Ku Hwang

Chang-Wahn Yu

Chong Hyun Lee

Eon-Young Hong

Il Min Kim

Young-Jin Moon

Hyun Myung Wu

Dong Weon Yoon

Se-Young Cho

Kwang Min Hyun

An apparatus and method for detecting synchronization and signals using block data processing in a receiving system are provided. To process an input signal, a cumulative matrix is obtained from an input vector signal for each frame generated from the signal. A primary eigenvector is extracted from the cumulative matrix, and the maximum value of a correlation vector is calculated from the extracted primary eigenvector. A time delay is detected by comparing the calculated maximum value of the correlation vector with a first threshold value, and a delay correlation vector is calculated from the detected time delay. Finally, synchronization and signals are detected by comparing the calculated delay correlation vector with a second threshold value.

Apparatus and method for detecting synchronization and signals using block data processing

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

Provided is a method for transmitting and receiving multi-input multi-output in a wireless backhaul network, including: selecting at least one pair of dual-polarized transmitting antennas to be activated among pairs of dual-polarized transmitting antennas of a transmitter; transmitting a signal through the selected pairs of dual-polarized transmitting antennas; and receiving, by pairs of dual-polarized receiving antennas of a receiver, the signal transmitted from the transmitter.

System for transmitting and receiving multi-input multi-output and method for transmitting and receiving multi-input multi-output using the same

There is provided a method for acquiring and modifying uplink and downlink synchronization, by which, if there is a possibility of ISI occurring due to incorrect downlink synchronization of a terminal with a base station, the terminal receives a ranging response from the base station, modifies incorrect downlink synchronization, and acquires uplink synchronization in accordance with modified downlink synchronization. The method for acquiring and modifying uplink and downlink synchronization efficiently prevents, in a cooperative communication network, discrepancy in signal transmission synchronization between the base stations, excessive attenuation of a transmitted signal, or a delay caused by a difference in reflection paths.

Method and apparatus for acquiring uplink and downlink synchronization between a plurality of base stations and a terminal in a cooperative communication network

Provided are a method and an apparatus for transmitting resource allocation information. In the case when a wireless resource for a new terminal is fixedly allocated to a fixed allocation zone, the apparatus for transmitting resource allocation information determines a resource allocation method of allocating the wireless resource and determines an allocation form of a resource that is allocated by a resource allocation method to select any one information displaying method of a plurality of information displaying methods of displaying allocation information on the allocated resource on the basis of the determined resource allocation method and resource allocation form. Next, the resource allocation information is generated and transmitted on the basis of the selected displaying method.

Method and apparatus for transmitting resource allocation information

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

Provided are a transmitting apparatus and voice data transmitting and receiving methods for providing VoIP services. When a call is started and an analog signal including a voice signal is input, the transmitting apparatus divides the analog signal into a plurality of voice data packets for transmission. Here, the plurality of voice data packets are generated by sampling with different phases in the same frequency. In addition, the transmitting apparatus inserts a time indication bit that is changed every transmission period into each of the voice data packets and transmits the voice data packets, and distinguishes voice data corresponding to a current transmission period based on the time indication bit.

Transmitter and method for transmitting and receiving of voice data for VoIP service

Disclosed is a method and apparatus for composing a received symbol signal modulated with a bit reflected Gray code into bit information. According to an embodiment of the present invention, a positive integer of the received symbol signal having bits is assigned according to the Gray mapping rule, and a sign is determined. A value that is indicative of an arrangement of the bits constituting the received symbol signal is calculated. A boundary value in at least one bit group consisting of the bits constituting the received symbol signal is acquired, and a difference from an absolute value of the received symbol signal is calculated. The received symbol signal is converted into information per bit using a value of the received symbol signal based on the positive integer and the determined sign, the value that is indicative of the bit arrangement, and the difference from the absolute value. Therefore, it is possible to reduce complexity in bitwise decomposition for an iterative decoder inevitably used in a receiver.

Method and apparatus for decomposing received symbol signal modulated with bit reflected gray code in bit information

Disclosed is a method of detecting signals at a receiver of a communication system with a multiple input multiple output antenna. With the signal detection method, a square of the distance between a received signal vector and a channel status-considered transmission symbol vector is calculated first, and the square of the distance is then classified into first and second components. The first component is minimized to calculate a plurality of first soft symbol estimates. A solution set of the first component is calculated on the basis of the plurality of first soft symbol estimates. The second component is minimized to calculate a plurality of second soft symbol estimates. A solution set of the second component is calculated on the basis of the plurality of second soft symbol estimates. A final solution set is calculated by doing the sum of the first component solution set and the second component solution.

Signal detection method and receiver

The present invention relates an apparatus and method of estimating a signal-to-noise ratio (SNR) of a received signal when the received signal has a timing offset. An apparatus for estimating a signal-to-noise ratio (SNR) according to an exemplary embodiment of the present invention includes a fast Fourier transform (FFT) unit that performs a fast Fourier transform on a received signal to convert the received signal into a frequency domain signal; a preamble selector that extracts a preamble from the frequency domain signal; a correlator that correlates the preamble to a preamble reference signal generated by a receiver to calculate a correlation value; an entire power estimator that calculates entire power; a noise power estimator that applies a differential demodulation method to the correlation value to remove a timing offset and calculate noise power; and an estimating unit that uses the entire power and the noise power to estimate the signal-to-noise ratio (SNR).

Apparatus and method of estimating signal-to-noise ratio

A subcarrier allocating apparatus allocating data to be transmitted to a plurality of orthogonal subcarriers in an orthogonal frequency division multiplexing (OFDM) system is provided. The apparatus includes a logical index generator generating a logical index for allocating a data subcarrier to a physical index, the logical index being included with only data subcarriers and the physical index indicating a location of a substantial subcarrier within a symbol, an intermediate index converter converting the logical index into an intermediate index by performing a given operation on the generated logical index and a pilot location constant, and a physical index converter converting the intermediate index into a physical index based on the number of data subcarriers on the left and right sides of a null subcarrier for insertion of a guard interval formed by the null subcarrier.

Subcarrier allocation apparatus and method, subcarrier de-allocation apparatus and method in OFDM system

In a decoding apparatus in a portable Internet terminal, a channel encoded symbol received from a transmitter is decoded by one of a chase-combining scheme and a code-combining scheme selected based on an ID value of the subpacket indicating a start position of the symbol. In this case, the chase-combining scheme is partly used for the encoded symbol of the information bit. With such a mode, decoding can be performed at a low code rate.

Decoding apparatus and method thereof

Disclosed is a demodulation apparatus for receiving signals by an adaptive modulation and coding method, and demodulating the signals, in an OFDMA based packet communication system, comprising: a QAM demapper for performing QAM demapping to the received signals by a modulation method using a maximum modulation ratio, until modulation methods for each of sub-channels are analyzed; a slot buffer for storing the data outputted from the QAM demapper; a channel decoder for decoding the data stored in the slot buffer and analyzing modulation methods for each sub-channels and transferring the analyzed modulation methods to the QAM demapper; and in at the same time, reading valid data from the data stored in the slot buffer, based on the analyzed modulation methods for each sub-channels, and demodulating the valid data.

Demodulation apparatus for efficiently embodying adaptive modulation and coding method in OFDMA based packet communication system and method thereof

The present invention relates to a method of calculating a log-likelihood ratio and a method of detecting a transmission signal. According to the present invention, when a transmission symbol candidate vector is detected on the basis of a received signal, a threshold value and an ML metric of each transmission symbol candidate vector are calculated and the ML metric that is larger than the threshold value is updated by the threshold value. Further, a log-likelihood ratio of the transmission signal bit is calculated using the updated ML metric and the threshold value, and a transmission signal is detected using the log-likelihood ratio.

Growing community of inventors

Daejeon, South Korea

Jun-Woo Kim