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1.发明授权Modulator, demodulator, and transmission system for use in OFDM transmission 有权用于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
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。
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2.发明授权Modulator, demodulator, and transmission system for use in OFDM transmission 有权用于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
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。
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3.发明授权公开(公告)号：US07843972B2
公开(公告)日：2010-11-30
申请号：US11312344
申请日：2005-12-21
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。
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4.发明申请公开(公告)号：US20060104195A1
公开(公告)日：2006-05-18
申请号：US11312344
申请日：2005-12-21
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。
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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。
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6.发明授权公开(公告)号：US07027464B1
公开(公告)日：2006-04-11
申请号：US09627781
申请日：2000-07-28
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。
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公开(公告)号：US06169751A
公开(公告)日：2001-01-02
申请号：US09036784
申请日：1998-03-09
IPC分类号： H04J100
CPC分类号： H04L27/2662 , H04L27/2656 , H04L27/2657 , H04L27/2675
摘要： An OFDM receiving apparatus converts a received OFDM signal based on two sampling timing signals to detect reference symbols intermittently inserted in the OFDM signal. Based on the detected reference symbols, a frame synchronization is established. Further, clock components in the reference symbols are extracted, and compared with the sampling timing signals only in the reference symbol duration to obtain a phase error. Based on the phase error, the sampling timing signal is controlled to establish a bit-synchronization. For this purpose, at least two samplers, delayer, and phase error holder are provided.
摘要翻译： OFDM接收装置基于两个采样定时信号来转换接收的OFDM信号，以检测在OFDM信号中间歇地插入的参考符号。 基于检测到的参考符号，建立帧同步。 此外，提取参考符号中的时钟分量，并且仅在参考符号持续时间内与采样定时信号进行比较以获得相位误差。 基于相位误差，采样定时信号被控制以建立位同步。 为此，提供至少两个采样器，延迟器和相位误差保持器。
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公开(公告)号：US20070121750A1
公开(公告)日：2007-05-31
申请号：US10573044
申请日：2005-03-09
申请人： Naganori Shirakata , Yasuo Harada , Koichiro Tanaka , Tomohiro Kimura , Shuya Hosokawa , Yoshio Urabe
发明人： Naganori Shirakata , Yasuo Harada , Koichiro Tanaka , Tomohiro Kimura , Shuya Hosokawa , Yoshio Urabe
IPC分类号： H04L1/02
CPC分类号： H04L27/2657 , H04L25/0204 , H04L27/2613 , H04L27/2675
摘要： In a transfer apparatus to which MIMO-OFDM is applied, a data transmission method and a data reception method are provided in which, even when there are frequency errors varying among transfer paths, the precision of estimation of an inverse propagation coefficient function can be improved, thereby making it possible to suppress a degradation in characteristics. Among symbols composed of a plurality of subcarriers orthognal to each other, the transfer apparatus uses, as a synchronization symbol, a symbol in which predetermined amplitudes and phases are assigned to a plurality of subcarriers spaced at predetermined frequency intervals. The synchronization symbol is divided into transmission antennas to generate a plurality of synchronization subsymbols, which are in turn simultaneously transmitted from a plurality of transmission antennas. A reception apparatus estimates a frequency error for each transfer path based on synchronization subsymbols included in signals received by a plurality of reception antennas, and based on the estimated frequency errors, corrects the received signals.
摘要翻译： 在应用MIMO-OFDM的传送装置中，提供数据传输方法和数据接收方法，其中即使在传输路径之间存在频率误差变化的情况下，也可以提高反向传播系数函数的估计精度 ，从而可以抑制特性的劣化。 在由彼此正交的多个子载波组成的符号之中，传送装置使用将预定的幅度和相位分配给以预定频率间隔隔开的多个子载波的符号作为同步符号。 同步符号被分成发送天线以产生多个同步子符号，这些同步子符号又从多个发送天线同时发送。 接收装置基于由多个接收天线接收的信号中包含的同步子符号估计每个传送路径的频率误差，并且基于估计的频率误差来校正接收到的信号。
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公开(公告)号：US07702027B2
公开(公告)日：2010-04-20
申请号：US10573044
申请日：2005-03-09
申请人： Naganori Shirakata , Yasuo Harada , Koichiro Tanaka , Tomohiro Kimura , Shuya Hosokawa , Yoshio Urabe
发明人： Naganori Shirakata , Yasuo Harada , Koichiro Tanaka , Tomohiro Kimura , Shuya Hosokawa , Yoshio Urabe
IPC分类号： H04B7/02
CPC分类号： H04L27/2657 , H04L25/0204 , H04L27/2613 , H04L27/2675
摘要： In a transfer apparatus to which MIMO-OFDM is applied, a data transmission method and a data reception method are provided in which, even when there are frequency errors varying among transfer paths, the precision of estimation of an inverse propagation coefficient function can be improved, thereby making it possible to suppress a degradation in characteristics. Among symbols composed of a plurality of subcarriers orthognal to each other, the transfer apparatus uses, as a synchronization symbol, a symbol in which predetermined amplitudes and phases are assigned to a plurality of subcarriers spaced at predetermined frequency intervals. The synchronization symbol is divided into transmission antennas to generate a plurality of synchronization subsymbols, which are in turn simultaneously transmitted from a plurality of transmission antennas. A reception apparatus estimates a frequency error for each transfer path based on synchronization subsymbols included in signals received by a plurality of reception antennas, and based on the estimated frequency errors, corrects the received signals.
摘要翻译： 在应用MIMO-OFDM的传送装置中，提供数据传输方法和数据接收方法，其中即使在传输路径之间存在频率误差变化的情况下，也可以提高反向传播系数函数的估计精度 ，从而可以抑制特性的劣化。 在由彼此正交的多个子载波组成的符号之中，传送装置使用将预定的幅度和相位分配给以预定频率间隔隔开的多个子载波的符号作为同步符号。 同步符号被分成发送天线以产生多个同步子符号，这些同步子符号又从多个发送天线同时发送。 接收装置基于由多个接收天线接收的信号中包含的同步子符号估计每个传送路径的频率误差，并且基于估计的频率误差来校正接收到的信号。
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公开(公告)号：US20100260084A1
公开(公告)日：2010-10-14
申请号：US12675588
申请日：2009-06-29
CPC分类号： H04W52/0216 , H04W76/28 , Y02D70/142 , Y02D70/144 , Y02D70/166 , Y02D70/168
摘要： Provided is a compact and low power consumption wireless communication system, including a base station and communication terminals, in which power consumption of the communication terminal is reduced. The base station alternately sets an active interval during which predetermined data communication is performed, and an inactive interval during which the predetermined data communication is not performed. During the active interval, a beacon including information indicating a start timing of a subsequent active interval is transmitted and received. During the inactive interval, a sub-beacon including information providing notice of a transmission timing of a subsequent beacon is transmitted and received. When receiving the sub-beacon, the communication terminal obtains the transmission timing of the subsequent beacon and stops a supply of power to an unit related to a wireless communication function until the transmission timing.
摘要翻译： 提供了一种紧凑且低功耗的无线通信系统，其包括基站和通信终端，其中通信终端的功耗被降低。 基站交替地设置执行预定数据通信的活动间隔，以及不执行预定数据通信的无效间隔。 在活动间隔期间，发送并接收包括指示后续活动间隔的开始定时的信息的信标。 在非活动间隔期间，发送并接收包括提供通知后续信标的发送定时的信息的子信标。 当接收到子信标时，通信终端获得后续信标的发送定时，并停止向与无线通信功能相关的单元的电力供应直到发送定时。
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