公开(公告)号：US07376194B2

公开(公告)日：2008-05-20

申请号：US10838123

申请日：2004-05-03

Applicant: Ki-Yun Kim

Inventor： Ki-Yun Kim

IPC: H04K1/10

CPC classification number: H04L27/2676 ,  H04L27/266 ,  H04L2027/0057

Abstract: Disclosed is a method for compensating for a residual frequency offset in an orthogonal frequency division multiplexing system comprising the steps of: a) performing a fast fourier transform for an input signal to convert the input signal into a serial signal; b) detecting signal power of the serial signal to control the passthrough a signal greater than a predetermined critical value; c) selecting each section of a quadrant for each passed signal; d) estimating a phase error in each section of the quadrant for one orthogonal frequency division multiplexing symbol with respect to the selected section of the quadrant; and e) frequency-oscillating a signal based on the estimated phase error, generating the input signal by multiplying an oscillated signal by a band-passed signal, and then returning to step a).

Abstract translation: 公开了一种用于补偿正交频分复用系统中的残余频率偏移的方法，包括以下步骤：a）对输入信号执行快速傅立叶变换以将输入信号转换为串行信号; b）检测串行信号的信号功率，以控制通过大于预定临界值的信号; c）为每个传递的信号选择象限的每个部分; d）针对所述象限的所选择的部分估计一个正交频分复用符号的所述象限的每个部分中的相位误差; 以及e）基于估计的相位误差对信号进行频率振荡，通过将振荡信号乘以带通信号产生输入信号，然后返回到步骤a）。

公开(公告)号：US07319660B2

公开(公告)日：2008-01-15

申请号：US10412262

申请日：2003-04-14

Applicant: Ki-yun Kim ,  Ho Kim ,  Jun-yun Lee ,  Hyung-jin Choi

Inventor： Ki-yun Kim ,  Ho Kim ,  Jun-yun Lee ,  Hyung-jin Choi

IPC: H04J11/00

CPC classification number: H04L27/2613 ,  H04L27/2656

Abstract: Provided is a frame synchronization pattern design and synchronization method by which in a transmitter of a communications system employing an orthogonal frequency division multiplexing (OFDM), a frame synchronization pattern is inserted into the starting part of a symbol frame, and by detecting the frame synchronization pattern in a receiver, synchronization of the OFDM transmitter and receiver is performed. Also, provided are a transmitter synchronization apparatus including an OFDM symbol frame generation unit, a frame synchronization pattern insertion unit, and an OFDM transmission signal conversion unit, and a receiver synchronization apparatus comprising a frame synchronization pattern inserted OFDM symbol frame conversion unit, a frame synchronization pattern detection unit, and a source data generation unit.Overcoming the conventional notion depending on the earlier art OFDM symbol standards, the OFDM symbol frame start detection method according to the present invention places a free-length code pattern, which is separately generated in a time domain, in the starting point of a frame and detects this pattern such that accuracy and efficiency greatly improve. Also, since the power value of a received signal is detected in the method, the communications system operates regardless of the frequency offset and phase offset. In addition, since a free-length pattern can be designed, the start point of a frame can be accurately detected in a seriously fading channel, by detecting a maximum peak based on correlation.

Abstract translation: 提供了一种帧同步模式设计和同步方法，在采用正交频分复用（OFDM）的通信系统的发射机中，将帧同步模式插入符号帧的起始部分，并通过检测帧同步 接收机中的模式，执行OFDM发射机和接收机的同步。 此外，提供了包括OFDM符号帧生成单元，帧同步码型插入单元和OFDM传输信号转换单元的发射机同步装置，以及包括帧同步码型插入OFDM符号帧转换单元的接收机同步装置， 同步模式检测单元和源数据生成单元。 根据本发明的OFDM符号帧起始检测方法克服了以前的OFDM符号标准的常规概念，将在时域中单独生成的自由长度码模式放在帧的起点处， 检测这种模式，使得精度和效率大大提高。 此外，由于在该方法中检测到接收信号的功率值，所以通信系统不管频率偏移和相位偏移如何运行。 此外，由于可以设计自由长度图案，因此通过基于相关性检测最大峰值，可以在严重衰落的信道中准确地检测帧的起始点。

公开(公告)号：US07554902B2

公开(公告)日：2009-06-30

申请号：US10420693

申请日：2003-04-23

Applicant: Ki-yun Kim ,  Ho Kim ,  Hyung-jin Choi

Inventor： Ki-yun Kim ,  Ho Kim ,  Hyung-jin Choi

IPC: H04J11/00

CPC classification number: H04L27/2607 ,  H04L27/2657 ,  H04L27/2675

Abstract: Provided is a transmission data frame in an orthogonal frequency division multiplexing (OFDM) burst mode transmission, and more particularly, a frequency offset estimating method and a channel equalizing method using a transmission data frame. In the transmission data frame used in the orthogonal frequency division multiplexing burst mode transmission, a length of a guard interval in a preamble area for frequency offset estimation and channel estimation varies depending on a channel environment not being limited in consideration of a size of a data symbol, and only data of ending part of the guard interval in the preamble is used to estimate frequency offset in consideration of intersymbol interference. In the frequency offset estimating method, desired frequency estimation efficiency can be satisfied with the small number of samples. Also, when channel equalization is performed, two symbols are averaged in a time area to reduce the accuracy of channel estimation due to Gaussian random noise. In a frequency area, by referring to weight placed on an adjacent subcarrier, a channel equalization coefficient is obtained to efficiently reduce Gaussian random noise.

Abstract translation: 提供了正交频分复用（OFDM）突发模式传输中的发送数据帧，更具体地，使用使用发送数据帧的频率偏移估计方法和信道均衡方法。 在正交频分复用突发模式传输中使用的发送数据帧中，用于频偏估计和信道估计的前同步码区域中的保护间隔的长度根据不受数据大小限制的信道环境而变化 符号，并且仅使用前导码中的保护间隔的结束部分的数据来估计考虑码间干扰的频率偏移。 在频率偏移估计方法中，可以利用少量样本来满足期望的频率估计效率。 此外，当执行信道均衡时，在时间区域中平均两个符号以降低由于高斯随机噪声导致的信道估计的准确度。 在频率区域中，通过参考相邻子载波上的权重，获得信道均衡系数以有效地降低高斯随机噪声。

公开(公告)号：US20100290557A1

公开(公告)日：2010-11-18

申请号：US12762103

申请日：2010-04-16

Applicant: Jung Hoon LEE ,  Daewon Lee ,  Ki Yun Kim ,  Joon Kui Ahn

Inventor： Jung Hoon LEE ,  Daewon Lee ,  Ki Yun Kim ,  Joon Kui Ahn

IPC: H04L27/00

CPC classification number: H04L27/2613 ,  H04L5/0007 ,  H04L5/0048 ,  H04L5/0053 ,  H04L25/0226 ,  H04L27/262 ,  Y02D70/12 ,  Y02D70/126

Abstract: A method and apparatus of transmitting a reference signal in a wireless communication system is provided. A reference signal sequence is generated by using a pseudo-random sequence. A portion or entirety of the reference signal sequence is mapped to at least one resource block and is transmitted. The pseudo-random sequence is generated by a gold sequence generator which is initialized with initial values obtained by using cell identifier. The reference signal provides low PAPR and high cross correlation characteristic.

公开(公告)号：US07321630B2

公开(公告)日：2008-01-22

申请号：US10692344

申请日：2003-10-24

Applicant: Ki-yun Kim ,  Hyung-jin Choi ,  Ho Kim

Inventor： Ki-yun Kim ,  Hyung-jin Choi ,  Ho Kim

IPC: H04L27/28 ,  G06F1/02

CPC classification number: H04L27/2657 ,  H04L27/2679

Abstract: An approximation method and system for series expansion of functions include the steps and functions, respectively, of: expanding an input function in Taylor series up to an (N−1)-th term; expanding the input function in Taylor series up to the N-th term; multiplying the expanded result up to the (N−1)-th term by a predetermined weight α; combining the expanded result up to the (N−1)-th term, multiplied by α, and the expanded result up to the N-th term; and dividing the combined result by (α+1).

Abstract translation: 函数串联扩展的近似方法和系统分别包括以下步骤和功能：将泰勒级数的输入函数扩展到第（N-1）项; 将泰勒系列中的输入函数扩展到第N个项; 将扩展结果乘以第（N-1）项预定权重α; 将扩展结果与第（N-1）项乘以α乘以扩展结果直到第N个项; 并将组合结果除以（α+ 1）。

公开(公告)号：US20050129135A1

公开(公告)日：2005-06-16

申请号：US10838123

申请日：2004-05-03

Applicant: Ki-Yun Kim

Inventor： Ki-Yun Kim

IPC: H04K1/10 ,  H04L27/00 ,  H04L27/06 ,  H04L27/26 ,  H04L27/28

CPC classification number: H04L27/2676 ,  H04L27/266 ,  H04L2027/0057

Abstract: Disclosed is a method for compensating for a residual frequency offset in an orthogonal frequency division multiplexing system comprising the steps of: a) performing a fast fourier transform for an input signal to convert the input signal into a serial signal; b) detecting signal power of the serial signal to control the passthrough a signal greater than a predetermined critical value; c) selecting each section of a quadrant for each passed signal; d) estimating a phase error in each section of the quadrant for one orthogonal frequency division multiplexing symbol with respect to the selected section of the quadrant; and e) frequency-oscillating a signal based on the estimated phase error, generating the input signal by multiplying an oscillated signal by a band-passed signal, and then returning to step a).

Abstract translation: 公开了一种用于补偿正交频分复用系统中的残余频率偏移的方法，包括以下步骤：a）对输入信号执行快速傅立叶变换以将输入信号转换为串行信号; b）检测串行信号的信号功率，以控制通过大于预定临界值的信号; c）为每个传递的信号选择象限的每个部分; d）针对所述象限的所选择的部分估计一个正交频分复用符号的所述象限的每个部分中的相位误差; 以及e）基于估计的相位误差对信号进行频率振荡，通过将振荡信号乘以带通信号产生输入信号，然后返回到步骤a）。