公开(公告)号：KR100789931B1

公开(公告)日：2008-01-02

申请号：KR1020060089273

申请日：2006-09-14

Applicant: 한국전자통신연구원

Inventor： 홍태철 ,  강군석 ,  안도섭 ,  이호진

IPC: H04L1/18 ,  H04L1/12

CPC classification number: H04L1/1819 ,  H04L1/1809

Abstract: A method of preventing successive packet errors according to a full receiver buffer in a selective repeat hybrid ARQ(Automatic Repeat Request) system is provided to efficiently use a bandwidth in case of coupling and using a hybrid ARQ and a selective ARQ in a system with a long round trip delay time. A method of preventing successive packet errors according to a full receiver buffer in a selective repeat hybrid ARQ(Automatic Repeat Request) system includes the steps of: transmitting a data packet to a receiver from a central station(401); checking the storage information of the data packet in an NACK(Negative ACKnowledgement) packet(404); storing the data packet in a re-transmission queue after transmitting a packet of parity bits to the receiver in case that the data packet is stored in the buffer(405,406); and maintaining the data packet stored in a transmission queue after re-transmitting the data packet in case that the data packet is not stored in the buffer(407,408).

Abstract translation: 提供了一种在选择性重复混合ARQ（自动重复请求））系统中根据完整接收器缓冲器来防止连续分组错误的方法，用于在具有混合ARQ和选择性ARQ的系统中耦合和使用混合ARQ和选择性ARQ的情况下有效地使用带宽 长途往返延迟时间。 一种在选择性重复混合ARQ（自动重复请求））系统中根据全接收器缓冲器防止连续分组错误的方法包括以下步骤：从中心站（401）向接收机发送数据分组; 在NACK（否定确认）分组（404）中检查数据分组的存储信息; 在数据包被存储在缓冲器中（405,406）的情况下，在将奇偶校验位分组发送到接收机之后，将数据分组存储在重发队列中; 以及在数据分组未存储在缓冲器中的情况下，在重新发送数据分组之后，保持存储在传输队列中的数据分组（407,408）。

公开(公告)号：KR100728241B1

公开(公告)日：2007-06-13

申请号：KR1020060091983

申请日：2006-09-21

Applicant: 한국전자통신연구원

Inventor： 김희욱 ,  강군석 ,  안도섭

IPC: H04B7/06 ,  H04B7/26

公开(公告)号：KR1020070049420A

公开(公告)日：2007-05-11

申请号：KR1020050106554

申请日：2005-11-08

Applicant: 한국전자통신연구원

Inventor： 김희욱 ,  강군석 ,  안도섭 ,  이호진

IPC: H04J11/00

CPC classification number: H04L27/2662 ,  H04B1/7077 ,  H04J13/0022 ,  H04J13/10 ,  H04L27/2613 ,  H04L27/2657

Abstract: 1. 청구범위에 기재된 발명이 속한 기술분야
본 발명은 ＯＦＤＭ 시스템에서 ＰＮ 수열을 이용한 프리엠블 수열 생성 방법과, 시간 동기 및 주파수옵셋 추정 방법에 관한 것임.
2. 발명이 해결하려고 하는 기술적 과제
본 발명은, OFDM 시스템의 송신측에서는 시간 도메인에서 자기상관 성질이 좋은 PN 수열이 되도록 주파수 도메인상에서 프리엠블 신호를 생성하고, 수신측에서는 상기 프리엠블 수열 생성시 사용된 PN(Pseudo Noise)수열을 이용하여 시간 도메인에서 심볼 동기 및 부반송파 주파수 옵셋 추정을 수행함으로써, OFDM 시스템에서 ＰＮ 수열을 이용한 프리엠블 수열 생성 방법과, 시간 동기 및 주파수옵셋 추정 방법을 제공하는데 그 목적이 있음.
3. 발명의 해결방법의 요지
본 발명은, OFDM 수신 시스템에서의 시간동기 및 주파수 옵셋 추정 방법에 있어서, 시간 도메인상에서 OFDM 수신신호의 프리엠블의 위치를 찾아 심볼 동기를 맞추는 시간동기 단계; 및 상기 시간동기 단계에서 동기화된 수신신호에 상기 PN 수열을 차동 부호화한 수열을 곱함으로써, 시간도메인 상에서 부반송파의 주파수 옵셋을 추정하는 주파수옵셋 추정 단계를 포함함.
4. 발명의 중요한 용도
본 발명은 OFDM 시스템에서의 시간 동기 및 주파수옵셋 추정 등에 이용됨.
직교 주파수 분할 다중화, OFDM, 프리엠블 수열, PN 수열, 주파수 옵셋 추정, 시간 동기

公开(公告)号：KR100651202B1

公开(公告)日：2006-11-29

申请号：KR1020050109207

申请日：2005-11-15

Applicant: 한국전자통신연구원

Inventor： 류선희 ,  강군석 ,  안도섭

IPC: H03M13/00

Abstract: A soft decision demodulation apparatus and a method thereof are provided to obtain a highly efficient bandwidth and a high performance by decoding repeatedly based on a soft decision value. A storing unit predetermines and stores the nearest constellation point of an opposite bit corresponding to a point of each constellation by dividing a constellation point region. A quantization unit(201) quantizes a channel receiving signal. A region determination unit(202) determines the nearest constellation point corresponding to the channel receiving signal quantized by the quantizing unit(201). An opposite constellation point detection unit(204) detects the nearest constellation point of the opposite bit corresponding to the nearest constellation point determined by the quantization unit(201) from the value previously stored in the storing unit. A soft decision demodulation value calculation unit(203) calculates a soft decision demodulation value based on the nearest constellation point determined by the region determination unit(202), the nearest constellation point of the opposite bit detected from the opposite constellation point detection unit(204), and the channel receiving unit.

Abstract translation: 提供软判决解调装置及其方法，以通过基于软判决值重复解码来获得高效带宽和高性能。 存储单元通过划分星座点区域来预先确定并存储与每个星座点相对应的相对位的最接近星座点。 量化单元（201）量化信道接收信号。 区域确定单元（202）确定与由量化单元（201）量化的信道接收信号相对应的最近星座点。 相对星座点检测单元（204）从先前存储在存储单元中的值中检测与由量化单元（201）确定的最接近星座点相对应的相反位的最接近星座点。 软判定解调值计算单元（203）基于由区域确定单元（202）确定的最接近星座点，从相对星座点检测单元（204）检测到的相反比特的最接近星座点来计算软判决解调值 ）和频道接收单元。

公开(公告)号：KR100441989B1

公开(公告)日：2004-07-30

申请号：KR1020010071271

申请日：2001-11-16

Applicant: 한국전자통신연구원

Inventor： 강군석 ,  최권휴 ,  김수영 ,  이호진

IPC: H04L27/26

CPC classification number: H04L27/2621

Abstract: A method for optimizing phase factors in partial transmit sequence orthogonal frequency division multiplexing system. The method includes initializing sub-block signals by applying an initial phase factor to the sub-block signals in all sub-blocks; setting a reference peak value with a peak value of a signal formed by combining the sub-block signals; selecting a phase value that minimizes the peak value of an output signal as the phase factor of each sub-block by applying a next phase value to each sub-block signal as the phase factor, and repeating this with respect to the remaining available phase values.

Abstract translation: 一种优化部分发射序列正交频分复用系统相位因子的方法。 该方法包括通过将初始相位因子应用于所有子块中的子块信号来初始化子块信号; 设置具有通过组合子块信号而形成的信号的峰值的参考峰值; 通过将下一个相位值作为相位因子应用于每个子块信号来选择使输出信号的峰值最小化的相位值作为每个子块的相位因子，并且针对剩余的可用相位值 。

公开(公告)号：KR1020040056473A

公开(公告)日：2004-07-01

申请号：KR1020020082858

申请日：2002-12-23

Applicant: 한국전자통신연구원 ,  브이케이 주식회사

Inventor： 최권휴 ,  강군석 ,  김수영 ,  오덕길

IPC: H04J13/10

CPC classification number: H04L27/2621 ,  H04B1/707 ,  H04B2201/70706 ,  H04L5/0021 ,  H04L25/03866 ,  H04L27/2602

Abstract: PURPOSE: A scrambling system and method in a multi-carrier CDMA and a recording medium storing its program are provided to reduce a PARR(Peak-to-Average Power Ratio) by changing a scrambling code according to user's combination of orthogonal codes. CONSTITUTION: A symbol modulator modulates a bit sequence of the kth user into symbols(S1), and a multiplier multiplies each modulated symbols to an orthogonal code to spread it to a chip sequence(S2). An adder adds the spread chip sequences in synchronization with a symbol timing, and an interleaver performs interleaving on chip sequences of M number of symbols to be transmitted and aligns chips making the same symbols at M-chip intervals(S3). A serial/parallel converter converts the aligned chip sequences into a parallel chip signal having the number of sub-carriers(S4), and a scrambling chip vector generator and a multiplier multiply the parallel chip signal to a scrambling code and transmit it to an inverse Fourier converter(S5). The inverse Fourier converter, the parallel/serial converter and a guard time inserting unit modulate one chip of each sub-carrier to generate a multi-carrier signal, and output it(S6).

Abstract translation: 目的：提供多载波CDMA和存储其程序的记录介质中的加扰系统和方法，以通过根据用户的正交码组合改变扰码来降低PARR（峰值平均功率比）。 构成：符号调制器将第k个用户的比特序列调制成符号（S1），并且乘法器将每个调制符号乘以正交码以将其扩展到码片序列（S2）。 加法器将码片序列与符号定时同步地相加，并且交织器对要发送的M个码元的码片序列执行交织，并且以M码片间隔对准使相同符号的码片（S3）。 串行/并行转换器将对准的码片序列转换成具有子载波数的并行码片信号（S4），并且加扰码片矢量发生器和乘法器将并行码片信号乘以扰码并将其发送到反相 傅里叶变换器（S5）。 逆傅立叶变换器，并行/串行转换器和保护时间插入单元调制每个子载波的一个芯片以产生多载波信号并输出​​（S6）。