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1. 发明授权

US06993083B1 Apparatus and method of OFDM demodulation 失效
标题翻译： OFDM解调的装置和方法
公开(公告)号：US06993083B1
公开(公告)日：2006-01-31
申请号：US09597764
申请日：2000-06-20
申请人： Naganori Shirakata , Tomohiro Kimura , Koichiro Tanaka , Hideki Nakahara , Yasuo Harada , Shuya Hosokawa
发明人： Naganori Shirakata , Tomohiro Kimura , Koichiro Tanaka , Hideki Nakahara , Yasuo Harada , Shuya Hosokawa
IPC分类号： H04L7/04
CPC分类号： H04L27/2665 , H04L27/2662
摘要： An apparatus and method for OFDM demodulation establish symbol synchronization to minimize between-symbol interference even under an environment where multipath occurs.An incoming signal is an OFDM signal including a transmission symbol structured by a valid symbol period and a guard interval, and a predetermined synchronization symbol is included in the OFDM signal for every transmission frame. A correlator calculates how a signal generated by a synchronization symbol generator and the OFDM signal are correlated. A correlation calculator then calculates a correlation therefrom. An integrator integrates the calculated correlation by the guard interval. A timing determination device determines symbol timing from the integrated correlation. An FFT window generator outputs operation timing for Fourier transform from the determined symbol timing. Based on the signal outputted from the FFT window generator, the apparatus for OFDM demodulation extracts a signal in the valid symbol period from the transmission symbol for demodulation.
摘要翻译：即使在发生多路径的环境下，用于OFDM解调的装置和方法建立符号同步以最小化符号间干扰。输入信号是包括由有效符号周期和保护间隔构成的发送符号的OFDM信号，并且对于每个发送帧，在OFDM信号中包括预定的同步符号。相关器计算由同步符号发生器和OFDM信号产生的信号的相关性。然后，相关计算器从其计算相关性。积分器将计算的相关性与保护间隔进行积分。定时确定装置从综合相关确定符号定时。 FFT窗口生成器从所确定的符号定时输出用于傅里叶变换的操作定时。基于从FFT窗口生成器输出的信号，OFDM解调装置从用于解调的发送符号中提取有效符号周期中的信号。

2. 发明授权

US07843972B2 OFDM signal transmission method, and OFDM signal transmitter/receiver 有权
标题翻译： OFDM信号传输方法和OFDM信号发射机/接收机
公开(公告)号：US07843972B2
公开(公告)日：2010-11-30
申请号：US11312344
申请日：2005-12-21
申请人： Hideki Nakahara , Koichiro Tanaka , Naganori Shirakata , Tomohiro Kimura , Yasuo Harada
发明人： Hideki Nakahara , Koichiro Tanaka , Naganori Shirakata , Tomohiro Kimura , Yasuo Harada
IPC分类号： H04J3/06 , H04J11/00 , H04J3/16
CPC分类号： H04L5/0048 , H04L5/0007 , H04L5/006 , H04L5/0085 , H04L25/022 , H04L25/0226 , H04L25/0232 , H04L27/2613 , H04L27/2657 , H04L27/2675
摘要： In an OFDM transmission method, in order to compensate any frequency response variation time wise resulted from any distortion in a transmission path, out-of-synchronization with passage of time, frequency drift, and phase shift, and to improve a demodulation characteristic, a PS detector in a receiver receiving an OFDM signal detects a pilot symbol. A PS1 TPFR calculator calculates a frequency response of the transmission path for a first pilot symbol, while a PS2 TPFR calculator calculates a frequency response of the transmission path for a second pilot symbol. Thereafter, a compensation vector calculator calculates compensation vectors from the frequency responses of the transmission path for both the first and second pilot symbols by linear approximation. A frequency response compensator compensates the frequency response variation of subcarriers in a data symbol based on the calculated compensation vectors.
摘要翻译：在OFDM传输方法中，为了补偿由于传输路径中的任何失真而导致的任何频率响应变化，与时间的流逝，频率漂移和相移失调，并且为了提高解调特性，在接收OFDM信号的接收机中的PS检测器检测导频符号。 PS1 TPFR计算器计算第一导频符号的传输路径的频率响应，而PS2 TPFR计算器计算用于第二导频符号的传输路径的频率响应。此后，补偿向量计算器通过线性近似来计算来自第一和第二导频符号的传输路径的频率响应的补偿向量。频率响应补偿器基于所计算的补偿向量来补偿数据符号中子载波的频率响应变化。

3. 发明授权

US07027464B1 OFDM signal transmission scheme, and OFDM signal transmitter/receiver 有权
标题翻译： OFDM信号传输方案和OFDM信号发射机/接收机
公开(公告)号：US07027464B1
公开(公告)日：2006-04-11
申请号：US09627781
申请日：2000-07-28
申请人： Hideki Nakahara , Koichiro Tanaka , Naganori Shirakata , Tomohiro Kimura , Yasuo Harada
发明人： Hideki Nakahara , Koichiro Tanaka , Naganori Shirakata , Tomohiro Kimura , Yasuo Harada
IPC分类号： H04J3/06
CPC分类号： H04L5/0048 , H04L5/0007 , H04L5/006 , H04L5/0085 , H04L25/022 , H04L25/0226 , H04L25/0232 , H04L27/2613 , H04L27/2657 , H04L27/2675
摘要： In an OFDM transmission scheme, in order to compensate any frequency response variations time wise resulted from any distortion in a transmission path, out-of-synchronization with passage of time, frequency drift, and phase shift, and to improve a demodulation characteristic, a PS detector in a receiver receiving an OFDM signal detects a pilot symbol. A PS1 TPFR calculator calculates a frequency response of the transmission path for a first pilot symbol, while a PS2 TPFR calculators calculates a frequency response of the transmission path for a second pilot symbol for a second pilot symbol. Thereafter, a compensation vector calculator calculates compensation vectors from the frequency responses of the transmission path for both of the first and second pilot symbols by linear approximation. A frequency response compensatory compensates the frequency response variation of subcarriers in a data symbol based on the calculated compensation vectors.
摘要翻译：在OFDM传输方案中，为了补偿由于传输路径中的任何失真，随时间流逝，频率漂移和相移而失调的任何频率响应变化，并且为了提高解调特性，在接收OFDM信号的接收机中的PS检测器检测导频符号。 PS1 TPFR计算器计算第一导频符号的传输路径的频率响应，而PS2 TPFR计算器计算用于第二导频符号的第二导频符号的传输路径的频率响应。此后，补偿矢量计算器通过线性近似从第一和第二导频符号的传输路径的频率响应中计算补偿矢量。频率响应补偿基于所计算的补偿向量来补偿数据符号中子载波的频率响应变化。

4. 发明申请

US20060104195A1 OFDM signal transmission method, and OFDM signal transmitter/receiver 有权
标题翻译： OFDM信号传输方法和OFDM信号发射机/接收机
公开(公告)号：US20060104195A1
公开(公告)日：2006-05-18
申请号：US11312344
申请日：2005-12-21
申请人： Hideki Nakahara , Koichiro Tanaka , Naganori Shirakata , Tomohiro Kimura , Yasuo Harada
发明人： Hideki Nakahara , Koichiro Tanaka , Naganori Shirakata , Tomohiro Kimura , Yasuo Harada
IPC分类号： H04J11/00
CPC分类号： H04L5/0048 , H04L5/0007 , H04L5/006 , H04L5/0085 , H04L25/022 , H04L25/0226 , H04L25/0232 , H04L27/2613 , H04L27/2657 , H04L27/2675
摘要： In an OFDM transmission scheme, in order to compensate any frequency response variation in time wise resulted from any distortion in a transmission path, out-of-synchronization with passage of time, frequency drift, and phase shift, and to improve a demodulation characteristic, a PS detector 261 in a receiver receiving an OFDM signal detects a pilot symbol. A PS1 TPFR calculator 62 calculates a frequency response of the transmission path for a first pilot symbol, while a PS2 TPFR calculator 63 calculates that for a second pilot symbol. Thereafter, a compensation vector calculator 64 calculates compensation vectors from the frequency responses of the transmission path for both of the first and second pilot symbols by linear approximation. A frequency response compensator 65 compensates the frequency response variation of subcarriers in a data symbol based on the calculated compensation vectors.
摘要翻译：在OFDM传输方案中，为了补偿由于传输路径中的任何失真，与时间的流逝，频率漂移和相移失调的时间上的任何频率响应变化，并且为了改善解调特性，在接收OFDM信号的接收机中的PS检测器261检测导频符号。 PS1 TPFR计算器62计算第一导频符号的传输路径的频率响应，而PS2 TPFR计算器63计算针对第二导频符号的频率响应。此后，补偿矢量计算器64通过线性近似从第一和第二导频符号的传输路径的频率响应中计算补偿矢量。频率响应补偿器65基于所计算的补偿向量来补偿数据符号中子载波的频率响应变化。

5. 发明授权

US06618352B1 Modulator, demodulator, and transmission system for use in OFDM transmission 有权
标题翻译：用于OFDM传输的调制器，解调器和传输系统
公开(公告)号：US06618352B1
公开(公告)日：2003-09-09
申请号：US09317961
申请日：1999-05-25
申请人： Naganori Shirakata , Yasuo Harada , Hiroshi Hayashino , Koichiro Tanaka , Hideki Nakahara
发明人： Naganori Shirakata , Yasuo Harada , Hiroshi Hayashino , Koichiro Tanaka , Hideki Nakahara
IPC分类号： H04J1100
CPC分类号： H04L27/2657 , H04L27/2679
摘要： An input of an OFDM signal containing known pilot carriers among given subcarriers is separated into subcarriers through Fourier transform in a fast Fourier transform unit. A data carrier phase error estimating unit obtains an amount of phase correction of each subcarrier on the basis of the pilot carriers in the separated subcarriers. A data carrier phase correcting unit corrects the phase of the separated subcarrier signal on the basis of the amount of phase correction. Thus, the phase errors of the subcarriers can be corrected and the OFDM symbols can be demodulated even if a frequency error and a timing error are occurring between the transmitter and receiver.
摘要翻译：在给定子载波中包含已知导频载波的OFDM信号的输入通过傅里叶变换在快速傅立叶变换单元中被分离成副载波。数据载波相位误差估计单元基于分离的子载波中的导频载波来获得每个子载波的相位校正量。数据载波相位校正单元根据相位校正量校正分离的副载波信号的相位。因此，即使在发射机和接收机之间出现频率误差和定时误差，也可以校正子载波的相位误差并且可以解调OFDM符号。

6. 发明授权

US06944122B2 Modulator, demodulator, and transmission system for use in OFDM transmission 有权
标题翻译：用于OFDM传输的调制器，解调器和传输系统
公开(公告)号：US06944122B2
公开(公告)日：2005-09-13
申请号：US10614291
申请日：2003-07-08
申请人： Naganori Shirakata , Yasuo Harada , Hiroshi Hayashino , Koichiro Tanaka , Hideki Nakahara
发明人： Naganori Shirakata , Yasuo Harada , Hiroshi Hayashino , Koichiro Tanaka , Hideki Nakahara
IPC分类号： H04L27/26 , H04J11/00
CPC分类号： H04L27/2657 , H04L27/2679
摘要： An input of an OFDM signal containing known pilot carriers among given subcarriers is separated into subcarriers through Fourier transform in a fast Fourier transform unit. A data carrier phase error estimating unit obtains an amount of phase correction of each subcarrier on the basis of the pilot carriers in the separated subcarriers. A data carrier phase correcting unit corrects the phase of the separated subcarrier signal on the basis of the amount of phase correction. Thus, the phase errors of the subcarriers can be corrected and the OFDM symbols can be demodulated even if a frequency error and a timing error are occurring between the transmitter and receiver.
摘要翻译：在给定子载波中包含已知导频载波的OFDM信号的输入通过傅里叶变换在快速傅立叶变换单元中被分离成副载波。数据载波相位误差估计单元基于分离的子载波中的导频载波来获得每个子载波的相位校正量。数据载波相位校正单元根据相位校正量校正分离的副载波信号的相位。因此，即使在发射机和接收机之间出现频率误差和定时误差，也可以校正子载波的相位误差并且可以解调OFDM符号。

7. 发明授权

US08170130B2 Transmission method and transmission system 有权
标题翻译：传输方式和传输系统
公开(公告)号：US08170130B2
公开(公告)日：2012-05-01
申请号：US11886072
申请日：2006-03-24
申请人： Hideki Nakahara , Hitoshi Takai , Koichiro Tanaka
发明人： Hideki Nakahara , Hitoshi Takai , Koichiro Tanaka
IPC分类号： H04B7/02
CPC分类号： H04L27/206 , H04B7/0678
摘要： A transmission device includes a differential encoding section for differentially encoding transmission data, a first waveform generation section, a second waveform generation section, and two transmission antennas. A reception device includes a reception antenna, a delay detection section, and a data determination section for low-pass filtering a delay detection signal. The reception device receives modulated signals modulated by using two waveforms having low correlations with each other. Thus, regardless of the presence or absence of delay dispersion in a propagation path and even in a high-speed fading in which the propagation path varies at high speed, a transmission diversity effect can be achieved, thereby making it possible to improve transmission characteristics.
摘要翻译：传输装置包括差分编码传输数据的差分编码部分，第一波形产生部分，第二波形发生部分和两个发射天线。接收装置包括接收天线，延迟检测部分和用于对延迟检测信号进行低通滤波的数据确定部分。接收装置接收通过使用彼此具有低相关性的两个波形调制的调制信号。因此，无论传播路径中是否存在延迟色散，并且即使在传播路径高速变化的高速衰落中也能够实现发送分集效果，能够提高传输特性。

8. 发明申请

US20080175221A1 Wireless Transmission System and Wireless Transmission Method and Wireless Station and Transmitting Station for Use Therein 有权
标题翻译：无线传输系统和无线传输方法及其使用的无线站和传输站
公开(公告)号：US20080175221A1
公开(公告)日：2008-07-24
申请号：US10569491
申请日：2005-09-16
申请人： Hideki Nakahara , Hitoshi Takai , Hidetoshi Yamasaki , Kenji Miyanaga , Koichiro Tanaka
发明人： Hideki Nakahara , Hitoshi Takai , Hidetoshi Yamasaki , Kenji Miyanaga , Koichiro Tanaka
IPC分类号： H04J3/06
CPC分类号： H04L1/1887 , H04B7/022 , H04B7/0667 , H04B7/0676 , H04B7/15592 , H04W84/042 , H04W84/047
摘要： The present invention provides a wireless transmission system in which it is possible to exert a maximum path diversity effect even if the maximum number of effective branches is limited to a small number. A transmission timing control section (23) determines a transmission start timing to be a timing obtained by delaying a reference timing by a predetermined delay amount. A modulation section (21) modulates a signal by a modulation scheme such that an anti-multipath property is exerted when the signal is demodulated on a receiver side, and transmits the modulated signal at the transmission start timing. In a receiving station (12), a demodulation section (33) demodulates the receive signal to obtain receive data. The predetermined delay amount is such that signals are received at the receiving station (12) at a plurality of signal-receiving timings, and the number of signal-receiving timings is less than or equal to a predetermined maximum number of effective branches, a difference between the signal-receiving timings is greater than or equal to a predetermined delay resolution and is less than or equal to a predetermined maximum delay.
摘要翻译：本发明提供一种无线传输系统，其中即使最大数量的有效分支被限制为少数，也可以施加最大路径分集效应。发送定时控制部（23）将发送开始定时确定为通过将基准定时延迟预定延迟量而获得的定时。调制部（21）通过调制方式对信号进行调制，使得当在接收机侧解调信号时施加抗多径特性，并在发送开始定时发送调制信号。在接收站（12）中，解调部（33）对接收信号进行解调，得到接收数据。预定延迟量使得在接收站（12）处以多个信号接收定时接收信号，并且信号接收定时的数量小于或等于预定的最大有效分支数，差在信号接收定时之间大于或等于预定的延迟分辨率并且小于或等于预定的最大延迟。

9. 发明授权

US07277501B2 Data receiving device 有权
标题翻译：数据接收装置
公开(公告)号：US07277501B2
公开(公告)日：2007-10-02
申请号：US10640655
申请日：2003-08-14
申请人： Kenichi Mori , Yoshio Urabe , Koichiro Tanaka , Hideki Nakahara , Hitoshi Takai
发明人： Kenichi Mori , Yoshio Urabe , Koichiro Tanaka , Hideki Nakahara , Hitoshi Takai
IPC分类号： H03D3/00 , H03K9/06
CPC分类号： H04L27/2331 , H04L5/06
摘要： A data receiving device is provided enabling a reduction in the time required for extracting a partial band signal, and capable of being easily made in a simple structure as an LSI device without requiring a plurality of analog circuits having the same characteristics. The data receiving device includes: a first sampler for sampling an in-phase signal I(t) at every predetermined sampling period and outputting the sampled in-phase signal; a second sampler for sampling a quadrature signal at every predetermined sampling period and outputting the sampled quadrature signal; a partial band extracting section structured by a complex filter for extracting partial band signals IBr, QBr from frequency components included in the sampled in-phase signal and the sampled quadrature signal; and first and second delay detection operating sections for performing a delay detecting process based on the partial band signals and outputting detection signals.
摘要翻译：提供一种数据接收装置，其能够减少提取部分频带信号所需的时间，并且能够容易地以简单的结构作为LSI装置，而不需要具有相同特性的多个模拟电路。数据接收装置包括：第一采样器，用于在每个预定采样周期对同相信号I（t）进行采样，并输出采样的同相信号; 第二取样器，用于在每个预定采样周期对正交信号进行采样，并输出采样的正交信号; 由复数滤波器构成的部分频带提取部分，用于从包括在采样的同相信号中的频率分量和采样的正交信号中提取部分频带信号IB，QB＆lt; SUB＆lt; ; 以及第一和第二延迟检测操作部分，用于基于部分频带信号执行延迟检测处理并输出检测信号。

10. 发明申请

US20070297549A1 Clock Recovery Circuit And Receiver Using The Circuit 有权
标题翻译：使用电路的时钟恢复电路和接收器
公开(公告)号：US20070297549A1
公开(公告)日：2007-12-27
申请号：US10591152
申请日：2005-03-18
申请人： Hideki Nakahara , Tomohiro Kimura , Hitoshi Takai , Kenichi Mori
发明人： Hideki Nakahara , Tomohiro Kimura , Hitoshi Takai , Kenichi Mori
IPC分类号： H04L7/00
CPC分类号： H04L7/0083 , H04L7/033
摘要： A clock recovery circuit capable of fast and accurate clock phase locking even in the presence of frequency shift and noise. The input signal includes, in order, a preamble with an alternating bit sequence pattern, a unique word and data. A detection unit detects zero crossings and measures the time interval therebetween. A 1-interval judgment unit judges whether an interval signal is within a predetermined range, and a 2-interval judgment unit sums two adjacent interval signals and judges whether the 2-interval signal is within a predetermined range. A control unit controls a zero-crossing signal based on the judgment result and outputs a valid zero-crossing signal if judged in the affirmative. A switching unit switches between outputting the zero-crossing signal and the valid zero-crossing signal as valid phase error information based on a frame reception signal input from a frame detection unit. A clock generation unit uses the valid phase error information in generating a symbol clock.
摘要翻译：即使存在频移和噪声，时钟恢复电路也能够快速准确地进行时钟相位锁定。输入信号按顺序包括具有交替位序列模式的前导码，唯一字和数据。检测单元检测过零点并测量它们之间的时间间隔。 1间隔判断单元判断间隔信号是否在预定范围内，并且2间隔判断单元对两个相邻间隔信号求和，并判断2间隔信号是否在预定范围内。控制单元根据判断结果控制过零信号，如果判断为肯定，则输出有效的过零信号。切换单元基于从帧检测单元输入的帧接收信号，在输出过零信号和有效过零信号之间切换为有效的相位误差信息。时钟生成单元在生成符号时钟时使用有效的相位误差信息。

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