Samsung Electronics Co., Ltd.

Qualcomm Incorporated

Sungkyunkwan University

Su-Jin Yoon

Min-Goo Kim

Hee-Jin Roh

Yong-Suk Moon

Hyun-Seok Oh

Gin-Kyu Choi

Hoon Jong Kang

Sang-Hyo Kim

Hyung-Jin Choi

Dong-Wook Park

Hyun-seok Yu

Yun-Ju Kwon

Se-Bin Im

Jun-Kyu Kang

Kwang-Man Ok

Hye-Jeong Lee

Se-bin Im

Chang-hyun Baik

Jeoung-Gil Lee

Jung-Hoon Joo

Hoon-Geun Song

Dae-Hong Lee

Chang-Hyun Baik

A correlation apparatus and method for frequency synchronization are provided. A frequency synchronization method of a receiver in a broadband wireless access communication system includes acquiring a highest correlation value by conducting a differential correlation of a variable interval between a received signal and a reference signal and performing a frequency synchronization according to the highest correlation value.

Correlation apparatus and method for frequency synchronization in broadband wireless access communication system

Disclosed is a method for detecting a frequency offset in an Orthogonal Frequency Division Multiplexing (OFDM) system. The method includes determining a first frequency index based on autocorrelation values calculated according to a frequency index for a pilot signal of a received symbol, accumulating the autocorrelation values calculated according to the frequency index for the pilot signal of the received symbol depending on a symbol count, and determining a second frequency index based on the accumulated autocorrelation values, and determining at least one of the first frequency index and the second frequency as a frequency offset according to channel quality.

Method and apparatus for detecting offset in an orthogonal frequency division multiplexing system

An apparatus and method for allocating a frequency resource to a user equipment (UE) in an orthogonal frequency division multiplexing (OFDM) mobile communication system. A base station receives feedback information including at least mobility information from the UE, and determines from the mobility information whether the UE belongs to a fast group or a slow group. The base station allocates a frequency resource for the UE according to an open-loop solution if the UE belongs to the fast group, allocates a frequency resource for the UE according to a closed-loop solution if the UE belongs to the slow group, and transmits data for the UE using the allocated frequency resource.

Apparatus and method for allocating frequencies in an OFDM mobile communication system supporting high speed downlink packet access service

An apparatus and method for recovering a carrier frequency of a received signal using a predefined symbol in an OFDM system is provided. A maximum value detector detects at least three values and their corresponding offsets in descending order among auto-correlation values calculated within a specific frequency offset range between a received signal and a predefined symbol. A frequency offset corrector compares a ratio of a first auto-correlation value to a second auto-correlation value with a predetermined first threshold, determines whether first and second frequency offsets corresponding to the first and second auto-correlation values are adjacent to each other if the ratio of the auto-correlation values is less than the first threshold, and determines an initial carrier frequency offset using a difference between the first frequency offset and a frequency offset correction value determined according to system, if the first and second frequency offsets are adjacent to each other and a ratio of the second auto-correlation value and a third auto-correlation value is greater than a predetermined second threshold.

Apparatus and method for recovering frequency in an orthogonal frequency division multiplexing system

An apparatus and method for carrier frequency synchronization in an Orthogonal Frequency Division Multiplexing (OFDM) system are provided for correcting an initial carrier frequency offset in the OFDM system. A metric generator for frequency estimation performs a first accumulation process for a value computed by multiplying a Phase Reference Symbol (PRS) generated from a reception stage by a Fast Fourier Transform (FFT) output signal for an OFDM symbol in a PRS position within a frame, acquires a differential symbol from a product of adjacent FFT output symbols, performs a second accumulation process for a real part extracted from the differential symbol, and outputs a metric value for the frequency estimation. A maximal value-related index generator compares metric values for initial frequency estimation within a predetermined frequency offset estimation range, and selects and outputs a maximal metric value as a frequency offset estimate.

Apparatus and method for carrier frequency synchronization in an OFDM system

A Phase Locked Loop (PLL) is provided for improving acquisition performance in an acquisition state, while preventing performance degradation in a steady state under a low SNR environment, during phase detection, a phase detecting method for the PLL, and a receiver using the same. The PLL determines a period to which an input signal belongs according to the input signal and a feedback signal, outputs an error signal corresponding to the input signal by using a formula (or algorithm) set for the determined period, oscillates a predetermined frequency signal according to the error signal, and feeds back the oscillated signal.

Phase locked loop, phase detecting method for the phase locked loop, and receiver using the same

An apparatus and a method for improving the performance of an error correction code in response to the influence of error propagation are disclosed. A receiver of a mobile communication system, which transmits/receives data at a high speed by means of the plurality of transmission antennas and the plurality of reception antennas, estimates a transmission signal of a specific path from a first received signal according to a preset criterion, measures an error component for each symbol of the estimated transmission signal, performs an error correction for symbols having a corresponding error component exceeding a preset value, detects transmission data from all symbols through a predetermined signal reverse-processing procedure, reconstructs a transmission signal from the transmission data, subtracts the reconstructed transmission signal from the received signal to generate a second received signal, and repeats the above operations until transmission data of all paths are detected from the second received signal.

Apparatus and method for canceling an interference signal in a mobile communication system using multiple antennas

A de-rate matching method and apparatus in a High Speed Downlink Packet Access (HSDPA) system are provided. In the de-rate matching apparatus and method, a collection buffer temporarily stores a received packet, a combining buffer stores the packet received from the collection buffer according to predetermined memory address information including information indicating the positions of bits punctured during the rate matching, a controller decodes high-speed shared common control channel (HS-SCCH) information including a predetermined hybrid automatic repeat request (HARQ) parameter received from the transmitter and provides overall control to de-rate matching between the collection buffer and the combining buffer, an address generator generates the memory address information based on the decoded HARQ parameter, an address buffer stores the memory address information, and a zero inserter initializes at least one of data stored at memory addresses of the combining buffer including memory addresses for the punctured, before the de-rate matching.

De-rate matching method and apparatus in a high speed downlink packet access system

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Suwon-si, South Korea

Su-Jin Yoon