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1.发明授权
公开(公告)号：US5682376A
公开(公告)日：1997-10-28
申请号：US572719
申请日：1995-12-14
申请人： Hiroshi Hayashino , Yasuo Harada , Tomohiro Kimura , Yasuhiro Uno , Hiroshi Oue
发明人： Hiroshi Hayashino , Yasuo Harada , Tomohiro Kimura , Yasuhiro Uno , Hiroshi Oue
CPC分类号： H04L27/2607 , H04L27/2614
摘要： A complex multiplier complex-multiplies a carrier modulation signal group for decoding the phases and amplitudes of a plurality of carriers which are orthogonal to each other on the frequency axis by a complex signal group having a predetermined specific pattern which varies in phase at random. An inverse Fourier transformer performs inverse Fourier transformation on an output of the complex multiplier, for transforming a digital signal which is multiplexed on the frequency axis to an OFDM signal on the time axis. A guard interval insertion part adds front and rear guard intervals to front and rear parts of each symbol of the OFDM signal respectively. The front and rear guard intervals include data which are identical to those of rear and front end parts of the corresponding symbol respectively. Arithmetic processing which is reverse to that on a transmission side is performed on a receiving side, whereby distortion of received data is removed. Thus, the OFDM signal can be transmitted with no waveform distortion on a data component of each symbol on the frequency axis after Fourier transformation even if a reflected wave is superposed on a direct wave due to a multipath.
摘要翻译： 复数乘法器复数乘法载波调制信号组，用于解码在频率轴上彼此正交的多个载波的相位和幅度，具有随机相位变化的预定特定模式的复信号组。 傅里叶逆变换器对复数乘法器的输出执行逆傅立叶变换，用于将在频率轴上复用的数字信号在时间轴上变换为OFDM信号。 保护间隔插入部分分别向OFDM信号的每个符号的前后部分添加前后保护间隔。 前后保护间隔包括与相应符号的后端部分和前端部分相同的数据。 在接收侧执行与发送侧相反的算术处理，从而去除接收数据的失真。 因此，即使由于多径而将反射波叠加在直接波上，也可以在傅立叶变换之后的频率轴上的每个符号的数据分量上不发送波形失真的OFDM信号。
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2.发明授权
公开(公告)号：US5774450A
公开(公告)日：1998-06-30
申请号：US580887
申请日：1995-12-29
申请人： Yasuo Harada , Tomohiro Kimura , Hiroshi Oue , Yasuo Nagaishi , Hiroshi Hayashino , Yasuhiro Uno
发明人： Yasuo Harada , Tomohiro Kimura , Hiroshi Oue , Yasuo Nagaishi , Hiroshi Hayashino , Yasuhiro Uno
CPC分类号： H04L27/2613 , H04L27/261 , H04L27/265 , H04L27/2656 , H04L27/2657 , H04L27/2662 , H04L27/2675 , H04L27/2679 , H04L27/2682
摘要： An orthogonal frequency division multiplexing signal transmitted from the transmitting end to the receiving end intermittently includes a particular symbol S0 having a predetermined particular pattern in addition to a symbol Sm including data to be transmitted. At the receiving end, the variation in the receiving level and/or the variation in the frequency band of a received signal are detected and corrected on the basis of the received particular symbol S0. Since the particular symbol S0 has a particular pattern, the variation in the level and/or the variation in the frequency are strongly correlated with the variation in the receiving level and/or the variation in the frequency band of the received signal. Consequently, the variation in the receiving level and/or the variation in the frequency band of the received signal can be accurately detected from the particular symbol S0 and consequently high-precision correction can be made.
摘要翻译： 从发送端到接收端间歇地发送的正交频分复用信号除了包括要发送的数据的符号Sm之外还包括具有预定特定模式的特定符号S0。 在接收端，基于所接收的特定符号S0来检测和校正接收信号的接收电平的变化和/或频带的变化。 由于特定符号S0具有特定的模式，所以电平和/或频率变化的变化与接收信号的接收电平的变化和/或频带的变化密切相关。 因此，可以从特定符号S0精确地检测接收电平的接收电平的变化和/或频带的变化，从而可以进行高精度校正。
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3.发明授权
公开(公告)号：US5771223A
公开(公告)日：1998-06-23
申请号：US621338
申请日：1996-03-25
申请人： Tomohiro Kimura , Yasuo Harada , Hiroshi Hayashino , Yasuhiro Uno
发明人： Tomohiro Kimura , Yasuo Harada , Hiroshi Hayashino , Yasuhiro Uno
CPC分类号： H04L1/0071 , H04L1/006 , H04L27/2647
摘要： A Fourier transform circuit in a receiver performs a Fourier transform on a orthogonal frequency division multiplexing signal received through a transmission channel for each symbol to sequentially reproduce a received reference vector sequence and a received vector sequence. An interleave circuit interleaves elements of the received reference vector sequence and the received vector sequence. A memory stores the received reference vector sequence. A vector modulation circuit modulates the received reference vector sequence by respective signal point vectors representing each signal point to generate a modulation vector sequence for each symbol. A metric generation circuit then obtains a difference between the received vector sequence and the modulation vector sequence to generate the difference as a branch metric sequence. A trellis decode circuit reproduces a data sequence on the basis of the branch metric sequence.
摘要翻译： 接收机中的傅里叶变换电路对通过每个符号的传输信道接收的正交频分多路复用信号执行傅里叶变换，以顺序再现接收的参考矢量序列和接收的矢量序列。 交错电路对所接收的参考矢量序列和接收的矢量序列的元素进行交织。 存储器存储所接收的参考矢量序列。 矢量调制电路通过表示每个信号点的相应信号点矢量来调制接收到的参考矢量序列，以生成每个符号的调制矢量序列。 然后，度量产生电路获得接收的矢量序列和调制矢量序列之间的差异，以产生差分作为分支度量序列。 网格解码电路基于分支度量序列再现数据序列。
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公开(公告)号：US5734972A
公开(公告)日：1998-03-31
申请号：US621340
申请日：1996-03-25
申请人： Hiroshi Hayashino , Yasuo Harada , Tomohiro Kimura , Yasuhiro Uno
发明人： Hiroshi Hayashino , Yasuo Harada , Tomohiro Kimura , Yasuhiro Uno
IPC分类号： H04L27/00 , H04L27/227 , H04B1/18
CPC分类号： H04L27/2273 , H04L2027/0055 , H04L2027/0065 , H04L2027/0095
摘要： A pilot signal (a signal having known phase information and a prescribed length) is inserted at a prescribed time interval in a signal transmitted from a transmitting end to a receiving end. An arc tangent operation circuit (22) performs an operation for arc tangent of the pilot signal in a received signal to obtain a phase of the pilot signal. A phase error operation circuit (24) determines for a phase error between the known phase information previously held in a memory (23) and an output from the arc tangent operation circuit (22). A linear approximation circuit (25) takes an output from the phase difference operation circuit (24) as a linear function of time, and linear-approximates the output. A frequency error operation circuit (26) obtains for a frequency error from a slope of an output from the linear approximation circuit (25). In response to the obtained frequency error, control of an oscillation frequency of a variable frequency oscillation circuit allows rapid automatic frequency control with high accuracy.
摘要翻译： 在从发送端发送到接收端的信号中，以规定的时间间隔插入导频信号（具有已知相位信息和规定长度的信号）。 反正切运算电路（22）在接收信号中进行导频信号的反正切运算，得到导频信号的相位。 相位误差运算电路（24）确定先前保存在存储器（23）中的已知相位信息与反正切运算电路（22）的输出之间的相位误差。 线性近似电路（25）将相位差运算电路（24）的输出作为时间的线性函数，对输出进行线性近似。 频率误差运算电路（26）从线性近似电路（25）的输出的斜率求出频率误差。 响应于获得的频率误差，可变频率振荡电路的振荡频率的控制允许高精度的快速自动频率控制。
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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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7.发明授权公开(公告)号：US07251503B2
公开(公告)日：2007-07-31
申请号：US10533207
申请日：2004-10-12
IPC分类号： H04B1/38
CPC分类号： H04B7/0808
摘要： During all or part of a time period during which pattern signals are received, a diversity receiving apparatus allows a gain control section to fix the gain of a gain amplifier section, allows an antenna switching section to sequentially switch the selection of antennas during antenna switching periods which are synchronized with averaging periods, and determines an antenna to receive data contained in a packet, based on the levels of average powers measured by an averaging section on an averaging period-by-averaging period basis.
摘要翻译： 在接收图案信号的时间段的全部或部分期间，分集接收装置允许增益控制部分固定增益放大器部分的增益，允许天线切换部分在天线切换周期期间顺序切换天线的选择 并且根据平均化周期平均化周期的平均值测量的平均功率的电平，确定用于接收分组中包含的数据的天线。
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8.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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10.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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