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公开(公告)号：KR101093851B1
公开(公告)日：2011-12-13
申请号：KR1020100030889
申请日：2010-04-05
Applicant: 성균관대학교산학협력단
IPC: H04J11/00
Abstract: 본 발명에 따른 OFDM 시스템에서의 훈련 심볼을 이용한 시간 옵셋 추정 방법은, 기법 1, 기법 2, 기법 3에 대해, 시간 옵셋을 추정하기 위한 모의 실험을 통해 상기 세 가지 기법에 의한 OFDM 심볼을 생성하는 단계와; 상기 OFDM 심볼을 ISI 다중경로 채널로 전송하는 단계; 상기 세 가지 기법들의 시간 측도의 값을 연산하고, 소정의 설정된 시간 옵셋 값과 각 기법들을 통해 추정한 시간 옵셋 값과의 차이를 나타내는 평균 제곱 오차(mean square error: MSE) 값을 연산하며, 각 기법들의 평균값을 연산하는 단계 및; 최적의 기법을 선택하기 위해 상기 기법들의 시간 측도의 값을 비교하고, 설정된 시간 옵셋 값을 이용하여 각 기법들을 통해 추정한 시간 옵셋 값과의 차이를 나타내는 평균 제곱 오차(MSE) 값과, 각 기법들의 평균값의 비교를 통해 각 기법의 시간 옵셋 추정 정확도를 비교하여 최적의 기법을 판단하는 단계를 갖추어 이루어진다.
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公开(公告)号：KR1020110122289A
公开(公告)日：2011-11-10
申请号：KR1020100041695
申请日：2010-05-04
Applicant: 성균관대학교산학협력단
CPC classification number: H04B7/024 , H04B7/15592 , H04L25/0202 , H04L27/2602
Abstract: PURPOSE: A cooperative communications system and an OFDM s symbol transmission method thereof are provided to prevent serious bit error rate performance degradation of data decoding due to the time synchronization error of a relay node by inserting a new cyclic prefix symbol. CONSTITUTION: Four OFDM(Orthogonal Frequency Division Multiplexing) blocks which are expressed one OFDM block as imaginary number double of a conjugate complex number of the other OFDM block are created by mixing successive two OFDM blocks in a source node. Time domain OFDM blocks are created by executing inverse discrete Fourier transform to the four OFDM blocks. A transmission OFDM symbols are created by inserting a first cyclic prefix symbol to the time domain OFDM blocks. The transmission OFDM symbols are transmitted to a plurality of relaying nodes. A plurality of relaying nodes creates encoded electrical transmission OFDM symbols.
Abstract translation: 目的：提供协作通信系统及其OFDM符号传输方法，以通过插入新的循环前缀符号来防止由于中继节点的时间同步错误引起的数据解码的严重误码率性能下降。 构成：通过在源节点中混合连续的两个OFDM块来创建被表示为一个OFDM块的另一个OFDM块的共轭复数的虚数倍的四个OFDM（正交频分复用）块。 通过对四个OFDM块执行逆离散傅里叶变换来创建时域OFDM块。 通过将第一循环前缀符号插入时域OFDM块来创建传输OFDM符号。 传输OFDM符号被发送到多个中继节点。 多个中继节点创建编码的电传输OFDM符号。
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公开(公告)号：KR101262560B1
公开(公告)日：2013-05-08
申请号：KR1020110071394
申请日：2011-07-19
Applicant: 성균관대학교산학협력단
IPC: H04L27/26
Abstract: 본발명은 OFDM 시스템에서반복되는훈련심벌을이용하는주파수옵셋추정방법에관한것이다. 상기방법은주파수옵셋을추정하기위한모의실험에대한 OFDM 심벌을생성하는단계; 생성된 OFDM 심벌을 AWGN(덧셈꼴백색정규잡음) 환경또는레일레이채널에서각각전송시키는단계; 상기 OFDM 심벌을수신하는단계; Moose의훈련심벌구조를이용하는주파수옵셋추정기법, Schimidl의훈련심벌구조를이용하는주파수옵셋추정기법, Morelli의훈련심벌구조를이용하는주파수옵셋추정기법, 및 Laourine의훈련심벌구조를이용하는주파수옵셋추정기법을이용하여상기주파수옵셋추정기법들각각에대하여상기수신된 OFDM 심벌의주파수옵셋을추정하고추정된주파수옵셋과의평균제곱오류값(mean square error: MSE)을구하는단계; 및상기주파수옵셋추정기법들각각에대하여구해진 MSE를신호대 잡음비(SNR)에대해비교함으로써최적의주파수옵셋추정기법을결정하는단계를포함한다.
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公开(公告)号：KR1020130041666A
公开(公告)日：2013-04-25
申请号：KR1020110106067
申请日：2011-10-17
Applicant: 성균관대학교산학협력단
IPC: H04L27/26
CPC classification number: H04L27/2657 , H04L27/265 , H04L27/2676
Abstract: PURPOSE: A blind-based frequency offset estimation method is provided to increase the performance in an irregular noise environment OFDM(Orthogonal Frequency Division Multiplexing) system. CONSTITUTION: A frequency offset estimation method includes a stage(S101) of receiving a reception signal in a protective range and an OFDM(Orthogonal Frequency Division Multiplexing) signal range, a stage(S102) of calculating the number of samples in the protective range the same with the number of samples in the reception signal including the same signal in the later part of the protective range and OFDM signal range, a stage(S103) summing the calculated samples, a stage(S104) of calculating an angle from the summed signal of the samples and a stage(S105) of calculating a frequency offset estimation value based on the calculated angle. [Reference numerals] (AA) Start; (BB) End; (S101) Step of receiving a reception signal in a protective range and an OFDM signal range; (S102) Step of obtaining samples amounting to the number of samples(N_G) in the protective range from the reception signal; (S103) Step of adding up the samples; (S104) Step of calculating an angle from the summed signal of the samples; (S105) Step of calculating a frequency offset estimation value from the calculated angle;
Abstract translation: 目的：提供基于盲的频偏估计方法，以提高不规则噪声环境OFDM（正交频分复用）系统的性能。 构成：频率偏移估计方法包括：接收保护范围内的接收信号和OFDM（正交频分复用）信号范围的级（S101），在保护范围内计算采样数的级（S102） 与在保护范围和OFDM信号范围的后半部分中包括相同信号的接收信号中的样本数相同，阶段（S103）对所计算的样本求和，从求和信号计算角度的阶段（S104） 以及基于计算出的角度来计算频率偏移估计值的级（S105）。 （附图标记）（AA）开始; （BB）结束; （S101）接收保护范围和OFDM信号范围内的接收信号的步骤; （S102）从所述接收信号获取所述保护范围内的样本数（N_G）的样本的步骤; （S103）将样本相加的步骤; （S104）从样本的和信号计算角度的步骤; （S105）从计算出的角度计算频率偏移估计值的步骤;
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25.发明授权샘플 표준 편차를 기초로 한 다중 경로 페이딩 채널에서 ＯＦＤＭ 시스템을 위한 타이밍 옵셋 추정 방법 및 이러한 방법을 사용하는 장치 有权基于多路径渐变通道中的样本标准偏差估计OFDM系统的时序偏移的方法和使用该方法的装置
公开(公告)号：KR101257014B1
公开(公告)日：2013-04-22
申请号：KR1020110065608
申请日：2011-07-01
Applicant: 성균관대학교산학협력단
IPC: H04L27/26
Abstract: 샘플 표준 편차를 기초로 한 다중 경로 페이딩 채널에서 OFDM 시스템을 위한 타이밍 옵셋 추정 방법 및 이러한 방법을 사용하는 장치가 개시되어 있다. 타이밍 옵셋 추정 방법은 OFDM 수신 신호를 입력으로 하는 제1 함수를 이용해 제1 타이밍 옵셋을 추정하고, 상기 제1 타이밍 옵셋을 이용하여 산출된 제1 구간에서 프리앰블 신호 및 OFDM 수신 신호를 입력으로 하는 제2 함수를 이용해 제2 타이밍 옵셋 및 제1 타이밍 매트릭을 산출하는 단계와 제2 타이밍 옵셋을 기초로 산출된 제2 구간에서 제1 타이밍 매트릭의 표준 편차값을 입력으로 하는 제3 함수를 이용해 제3 타이밍 옵셋을 산출하는 단계를 포함할 수 있다. 따라서, 타이밍 옵셋을 추정 시 신호 경로 성분의 랜덤성에 강인한 특성을 갖는다.
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Patent Agency Ranking
公开(公告)号：KR1020130038731A
公开(公告)日：2013-04-18
申请号：KR1020110103246
申请日：2011-10-10
Applicant: 성균관대학교산학협력단
CPC classification number: H04L27/2657 , H04L27/265
Abstract: PURPOSE: A method and an apparatus of estimating a frequency offset based on training symbols in a wireless communication system are provided to improve estimation performance of the frequency offset under various noise environments including non-normal distribution noise as well as normal distribution noise. CONSTITUTION: A method of estimating a frequency offset based on training symbols in a wireless communication system comprise of: receiving signals comprising N samples(S101); obtaining N/2 samples from the received signals(S102); summing the N/2 samples(S103); finding an angle from the sum of N/2 samples(S104); and calculating an offset estimate based on the angle(S1050). [Reference numerals] (AA) Start; (BB) End; (S101) Step of receiving input signals; (S102) Step of obtaining N/2 samples from the received signals; (S103) Step of summing the N/2 samples; (S104) Step of finding an angle from the sum signal of the N/2 samples; (S105) Step of calculating an offset estimate from the found angle;
Abstract translation: 目的：提供一种基于无线通信系统中的训练符号估计频率偏移的方法和装置，以改善包括非正态分布噪声以及正态分布噪声在内的各种噪声环境下的频率偏移的估计性能。 构成：基于无线通信系统中的训练符号估计频率偏移的方法包括：接收包括N个采样的信号（S101）; 从接收到的信号中获得N / 2个样本（S102）; 对N / 2样本进行求和（S103）; 从N / 2个样本的和求出角度（S104）; 以及基于所述角度计算偏移估计（S1050）。 （附图标记）（AA）开始; （BB）结束; （S101）接收输入信号的步骤; （S102）从接收到的信号中获取N / 2个样本的步骤; （S103）对N / 2个样本求和的步骤; （S104）从N / 2个样本的和信号求出角度的步骤; （S105）从所述发现角度计算偏移估计的步骤;
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公开(公告)号：KR1020130011694A
公开(公告)日：2013-01-30
申请号：KR1020110073024
申请日：2011-07-22
Applicant: 성균관대학교산학협력단
CPC classification number: H04L27/2678 , H04L27/265
Abstract: PURPOSE: A frequency offset estimation method and apparatus based on local optimum estimation in a wireless communication system are provided to estimate a frequency offset with high performance in various noise environments by using a frequency offset estimation method. CONSTITUTION: A frequency offset based on the initial offset of a OFDM(Orthogonal Frequency Division Multiplexing) reception signal having non-uniform noise and guard interval(GI) and local optimum estimation(LOE) section is estimated. A frequency offset having the minimum difference between the frequency offset of the each estimated LOE section and the initial offset of the each LOE section is selected as the final frequency offset. A frequency offset of the each LOE section is estimated by a predetermined equation. A non-uniform noise included in the OFDM reception signal has the Cauchy distribution. [Reference numerals] (AA) Received signal; (BB) Selecting ε^p with minimum |ε^p-ε_p|; (CC) Final estimated value
Abstract translation: 目的：提供一种基于无线通信系统中局部最优估计的频率偏移估计方法和装置，通过使用频率偏移估计方法在各种噪声环境中估计具有高性能的频偏。 构成：估计基于具有不均匀噪声和保护间隔（GI）和局部最佳估计（LOE）部分的OFDM（正交频分复用）接收信号的初始偏移的频率偏移。 选择具有每个估计LOE部分的频率偏移与每个LOE部分的初始偏移之间的最小差异的频率偏移作为最终频率偏移。 通过预定的等式来估计每个LOE部分的频率偏移。 包含在OFDM接收信号中的非均匀噪声具有柯西分布。 （附图标记）（AA）接收信号; （BB）选择ε^ p，最小|ε^ p-ε_p|; （CC）最终估算值
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公开(公告)号：KR1020130010636A
公开(公告)日：2013-01-29
申请号：KR1020110071394
申请日：2011-07-19
Applicant: 성균관대학교산학협력단
IPC: H04L27/26
CPC classification number: H04L27/2672
Abstract: PURPOSE: A frequency offset estimation method using repeated training symbol in an OFDM system is provided to offer a proper standard of use by determining a frequency estimation technique corresponding to the situation. CONSTITUTION: An OFDM symbol regarding the simulation for estimating the frequency offset. The generated OFDM symbol is transmitted in AWGN(additive white Gaussian noise) environment or Rayleigh channel. The OFDM symbol is received. The frequency offset of the received OFDM symbol is estimated using each frequency offset estimation technique. The mean square error(MSE) of the estimated frequency offset is obtained. The obtained MSE using the frequency offset estimation method is compared with the signal to noise ratio. According to the compared results, the optimal frequency offset technique is decided. [Reference numerals] (AA) Generating an OFDM symbol; (BB) Transmission; (CC) Setting normalization frequency offset; (DD) Comparing accuracy and selecting an optimal technique
Abstract translation: 目的：提供一种在OFDM系统中使用重复训练符号的频率偏移估计方法，通过确定对应于该情况的频率估计技术来提供适当的使用标准。 构成：关于用于估计频率偏移的模拟的OFDM符号。 所生成的OFDM符号在AWGN（加性白高斯噪声）环境或瑞利信道中传输。 接收OFDM符号。 使用每个频率偏移估计技术来估计接收的OFDM符号的频率偏移。 获得估计频偏的均方误差（MSE）。 将获得的使用频偏估计方法的MSE与信噪比进行比较。 根据比较结果，确定最佳频偏技术。 （附图标记）（AA）生成OFDM符号; （BB）传输; （CC）设置归一化频率偏移; （DD）比较精度和选择最佳技术
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公开(公告)号：KR1020120124643A
公开(公告)日：2012-11-14
申请号：KR1020110042422
申请日：2011-05-04
Applicant: 성균관대학교산학협력단
CPC classification number: H04L27/2678 , H04L27/0006 , H04L27/2614
Abstract: PURPOSE: A method for analyzing performance of a spectrum sensing technique based on Cyclostationarity is provided to select a spectrum sensing technique of excellent performance according to channel characteristics by comparing detection probability performance. CONSTITUTION: An OFDM(Orthogonal Frequency Division Multiplexing) symbol is obtained for an OFDM signal(S100). An autocorelation function is calculated using the symbol of the OFDM signal(S200) A CAF(Cyclic Autocorrelation Function) is calculated using the autocorelation function(S300). SCD(Spectral Correlation Density) is calculated using a cyclic autocorrelation function(S400). Test statistics are calculated(S500). The spectrum sensing performance of each techniques is determined through SNR(Signal Noise Ratio) comparison based on the test statistics of techniques(S600). [Reference numerals] (AA) Start; (BB) End; (S100) Symbol acquisition step; (S200) Autocorrelation function calculation step; (S300) CAF calculation step; (S400) SCD calculation step; (S500) Test statistics calculation step; (S600) Performance evaluation step
Abstract translation: 目的：提出一种基于循环平稳性分析频谱感测技术性能的方法，通过比较检测概率性能，根据信道特性选择出色性能的频谱感知技术。 构成：对于OFDM信号，获得OFDM（正交频分复用）符号（S100）。 使用OFDM信号的符号计算自相关函数（S200）。使用自相关函数计算CAF（循环自相关函数）（S300）。 使用循环自相关函数计算SCD（光谱相关密度）（S400）。 计算测试统计（S500）。 通过基于技术测试统计的信噪比（Signal Noise Ratio，SNR Noise Signal Ratio，SNR）来确定每种技术的频谱感测性能（S600）。 （附图标记）（AA）开始; （BB）结束; （S100）符号获取步骤; （S200）自相关函数计算步骤; （S300）CAF计算步骤; （S400）SCD计算步骤; （S500）测试统计计算步骤; （S600）性能评估步骤
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30.发明公开다중경로 페이딩 채널에서 타이밍 추정이 가능한 ＯＦＤＭ 수신기, 이를 포함하는 ＯＦＤＭ 시스템 및 이들의 타이밍 추정방법 有权OFDM接收器能够估计多路径渐变信道中的时序，具有该OFDM信道的OFDM系统及其时序估计方法
公开(公告)号：KR1020110135661A
公开(公告)日：2011-12-19
申请号：KR1020100055515
申请日：2010-06-11
Applicant: 성균관대학교산학협력단
CPC classification number: H04L27/2647 , H04L25/03006
Abstract: PURPOSE: An orthogonal frequency division multiplexing(OFDM) receiver which estimates timing in a multi-path fading channel, an OFDM system including the same, and a timing estimation method thereof are provided to improve timing estimation performance by eliminating timing errors. CONSTITUTION: A first timing estimation part(110) calculates a timing metric value based on an autocorrelation function of a received signal including a baseband orthogonal frequency division multiplexing(OFDM) sample signal. The first timing estimation part calculates a first timing estimation value based on the calculated timing metric value. A second timing estimation part(120) calculates a filtered timing metric value based on a cross-correlation function between the received signal and a preamble signal in a first timing estimation range based on the first timing estimation value. The second timing estimation part calculates a second timing estimation value based on the filtered timing metric value. An optimum-timing estimation part(130) calculates an optimum-timing estimation value by comparing an amplification amount.
Abstract translation: 目的：提供一种用于估计多径衰落信道中的定时的正交频分复用（OFDM）接收机，包含该定时的OFDM系统及其定时估计方法，以通过消除定时误差来提高定时估计性能。 构成：第一定时估计部（110）基于包括基带正交频分复用（OFDM）采样信号的接收信号的自相关函数来计算定时度量值。 第一定时估计部分基于所计算的定时度量值来计算第一定时估计值。 第二定时估计部分（120）基于第一定时估计值，在第一定时估计范围内，基于接收信号和前同步码信号之间的互相关函数来计算经滤波的定时度量值。 第二定时估计部分基于滤波的定时度量值计算第二定时估计值。 最佳定时估计部（130）通过比较放大量来计算最佳定时估计值。
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