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公开(公告)号：US5473702A
公开(公告)日：1995-12-05
申请号：US70233
申请日：1993-06-02
CPC分类号： H04R3/005 , H04R2410/05
摘要： An adaptive filter estimates the noise component in a primary audio signal by convolving a secondary audio signal with a set of coefficients. The estimated noise component is subtracted from the primary audio signal to produce an output signal. During steady-state operation, the adaptive filter coefficients are updated as to minimize the difference between the primary audio signal and the estimated noise component. Steady-state operation is identified automatically by monitoring the power level of the primary or secondary audio signal, or the power level of the output signal. Coefficient updating is suspended when the monitored power level rises from a steady state to an unsteady state, and is resumed when the monitored power level returns to its previous steady-state level, or settles into a new steady state.
摘要翻译： 自适应滤波器通过利用一组系数卷积次音频信号来估计主音频信号中的噪声分量。 从主音频信号中减去估计的噪声分量以产生输出信号。 在稳态操作期间，更新自适应滤波器系数以最小化主音频信号和估计噪声分量之间的差异。 通过监视主要或次要音频信号的功率电平或输出信号的功率电平，可以自动识别稳态运行。 当监视的功率电平从稳定状态上升到不稳定状态时，系统更新被暂停，并且当监视的功率电平恢复到其先前的稳态电平或恢复到新的稳定状态时，系统恢复。
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公开(公告)号：US5905413A
公开(公告)日：1999-05-18
申请号：US69837
申请日：1998-04-30
摘要： A digital modulator capable of obtaining a high FM modulation index and reducing the quantization noise without increasing the sampling frequency of an A/D converter of input voice. A phase variation .phi.(Ts) of the digital data (Ts is the sampling period) produced on the basis of the output from the A/D converter is divided by a predetermined integer N (N>1) by a divider, and is fed to an integrator. The integrator integrates the divided phase variation .phi.(Ts)/N for every time interval Ts/N, thereby producing a phase component .phi.(t) of the complex envelope of the modulation signal. The phase component .phi.(t) is resolved into cosine and sine components at the time interval Ts/N. The cosine and sine signals are D/A converted into analog signals which are quadrature modulated by a quadrature modulator.
摘要翻译： 一种数字调制器，能够在不增加输入语音的A / D转换器的采样频率的情况下获得高FM调制指数并降低量化噪声。 基于来自A / D转换器的输出产生的数字数据（Ts是采样周期）的相位变化phi（Ts）被分频器除以预定的整数N（N> 1），并被馈送 给集成商。 积分器对每个时间间隔Ts / N对分割相位变化phi（Ts）/ N进行积分，从而产生调制信号的复包络的相位分量phi（t）。 相位分量phi（t）以时间间隔Ts / N被分解为余弦和正弦分量。 余弦和正弦信号被D / A转换成由正交调制器正交调制的模拟信号。
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公开(公告)号：US5751198A
公开(公告)日：1998-05-12
申请号：US755016
申请日：1996-11-22
CPC分类号： H04L27/2071 , H03C3/00
摘要： A digital modulator capable of obtaining a high FM modulation index and reducing the quantization noise without increasing the sampling frequency of an A/D converter of input voice. A phase variation .phi.(Ts) of the digital data (Ts is the sampling period) produced on the basis of the output from the A/D converter is divided by a predetermined integer N (N>1) by a divider, and is fed to an integrator. The integrator integrates the divided phase variation .phi.(Ts)/N for every time interval Ts/N, thereby producing a phase component .phi.(t) of the complex envelope of the modulation signal. The phase component .phi.(t) is resolved into cosine and sine components at the time interval Ts/N. The cosine and sine signals are D/A converted into analog signals which are quadrature modulated by a quadrature modulator.
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公开(公告)号：US06404886B1
公开(公告)日：2002-06-11
申请号：US09556973
申请日：2000-04-24
申请人： Tatsumasa Yoshida , Masashi Takada
发明人： Tatsumasa Yoshida , Masashi Takada
IPC分类号： H04M908
CPC分类号： H04M9/082
摘要： An echo canceling apparatus has two microphones, both receiving an acoustic signal including a near-end speech component and an echo component. A first adaptive filter cancels the echo component in the output of the first microphone, obtaining a first residual signal. A second adaptive filter cancels the echo component in the output of the second microphone, obtaining a second residual signal. The two residual signals are added together with a timing delay compensating for the delay between their near-end speech components. In the resulting sum signal, the near-end speech component is enhanced, while the echo component, and a near-end background noise component, are relatively weakened.
摘要翻译： 回波消除装置具有两个麦克风，两个麦克风都接收包括近端语音分量和回波分量的声信号。 第一自适应滤波器消除第一麦克风的输出中的回波分量，获得第一残差信号。 第二自适应滤波器消除第二麦克风的输出中的回波分量，获得第二残差信号。 两个残差信号与补偿其近端语音分量之间的延迟的定时延迟相加在一起。 在得到的和信号中，近端语音分量被增强，而回波分量和近端背景噪声分量相对减弱。
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公开(公告)号：US06480722B1
公开(公告)日：2002-11-12
申请号：US09300472
申请日：1999-04-28
申请人： Masashi Takada , Tatsumasa Yoshida
发明人： Masashi Takada , Tatsumasa Yoshida
IPC分类号： H04B1500
CPC分类号： H04B1/1027 , H04B17/318
摘要： Radio receivers which switches the received voice signal according to a supervisory signal used for supervising the condition of the propagation path through which the voice signal is transmitted are known. However, if the reception level of the radio wave received by a conventional radio receiver is low, the level of the supervisory signal becomes lower while the level of the noise accompanying the supervisory signal becomes higher, whereby the noise acts like the supervisory signal so as to provide a voice signal containing a lot of noise to the user of the radio receiver. To solve this problem, the radio receiver according to the present invention compares the level of the supervisory signal and the level of the noise accompanying the supervisory signal, so as to control the outputting of the voice signal according to the comparison result.
摘要翻译： 根据用于监视通过其发送语音信号的传播路径的状况的监视信号来切换接收的语音信号的无线电接收机是已知的。 然而，如果常规无线电接收机接收的无线电波的接收电平低，则监控信号的电平变低，同时伴随监视信号的噪声的电平变高，由此噪声像监控信号一样作为 以向无线电接收机的用户提供包含大量噪声的语音信号。 为了解决这个问题，根据本发明的无线电接收机将监控信号的电平与伴随监视信号的噪声电平进行比较，以便根据比较结果来控制语音信号的输出。
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公开(公告)号：US4386328A
公开(公告)日：1983-05-31
申请号：US254071
申请日：1981-04-14
申请人： Yoshio Masuda , Atsushi Fukasawa , Takuro Sato , Tatsumasa Yoshida , Hiromi Ando
发明人： Yoshio Masuda , Atsushi Fukasawa , Takuro Sato , Tatsumasa Yoshida , Hiromi Ando
CPC分类号： H01P1/2056 , H01P7/10
摘要： A high frequency filter for frequencies higher than the VHF band comprising of a closed conductive housing (53), a pair of input and/or output means (54) like an antenna provided at both the extreme ends (53-5, 53-6) of said housing (53), a plurality of resonators (51-1 through 51-5, and 51a-1 through 51a-5) arranged on a straight line between said antennas (54), each of said resonators having an elongated inner conductor (51a-1 through 51a-5) with a circular cross section, and an elongated rectangular dielectric body (51-1 through 51-5) surrounding said inner conductor, one end of each of said resonators being fixed at the single plane (53-1) of the housing (53) and the other end of each of said resonators being free standing. The length of said inner conductor and the dielectric body is substantially 1/4 wavelength, and the duration (52-1 through 52-4 ) between two resonators is determined according to the specified coupling coefficient for the desired characteristics of the filter. Due to the rectangular dielectric body (51-1 through 51-5), each resonator is stably mounted on the housing (53), and then, the stable characteristics of the filter is obtained. Thus, the use in a vibrated circumstance like a mobile communication is possible. That rectangular dielectric body (51-1 through 51-5) also provides the larger coupling coefficients between resonators, and then, the wideband filter can be obtained.
摘要翻译： 一种用于频率高于VHF频带的高频滤波器，包括封闭导电壳体（53），一对输入和/或输出装置（54），类似于设置在两端的天线（53-5,53-6 ），布置在所述天线（54）之间的直线上的多个谐振器（51-1至51-5和51a-1至51a-5），每个所述谐振器具有细长的内部 具有圆形横截面的导体（51a-1至51a-5）和围绕所述内部导体的细长矩形电介质体（51-1至51-5），每个所述谐振器的一端固定在单个平面 （53）的另一端，并且每个所述谐振器的另一端是独立的。 所述内部导体和介电体的长度基本上为1/4波长，并且根据用于滤波器的期望特性的规定的耦合系数来确定两个谐振器之间的持续时间（52-1至52-4）。 由于矩形电介质体（51-1至51-5），每个谐振器稳定地安装在壳体（53）上，然后获得滤波器的稳定特性。 因此，可以在诸如移动通信的振动环境中使用。 该矩形电介质体（51-1至51-5）也在谐振器之间提供较大的耦合系数，然后可获得宽带滤波器。
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公开(公告)号：US06208845B1
公开(公告)日：2001-03-27
申请号：US09112196
申请日：1998-07-09
申请人： Tatsumasa Yoshida
发明人： Tatsumasa Yoshida
IPC分类号： H04B104
CPC分类号： H03C3/08
摘要： A frequency-modulated signal transmitter and frequency modulation method are provided wherewith the linearity of an FM modulated signal is secured even when the level of frequency modulation after FM modulation is low. A level-subtraction circuit 24 is provided between a speech processing circuit 20 and a frequency modulator circuit 22 for subtracting the signal level of the speech-processed signal D2 from the speech processing circuit. The level-subtraction circuit comprises a level-subtraction stage 28, to which the speech-processed signal is input, that outputs a level-subtracted voice signal to the FM modulator circuit, and an average FM noise level setting stage 26 for setting the average level (±Esn) of the FM noise generated in the frequency modulator circuit and outputting that average FM noise level (±Esn) to the level-subtraction stage. In the level-subtraction stage, a signal in which the signal D2 and the average FM noise level (±Esn) have been added is obtained as a level-regulated voice signal, which level-regulated voice signal is sent as the modulating signal to the FM modulator circuit. The level subtraction may be implemented by either analog or digital processing.
摘要翻译： 即使在FM调制后的调频电平低的情况下，也提供调频信号发送器和频率调制方法，即使FM调制信号的线性也得到保证。 在语音处理电路20和频率调制器电路22之间提供电平减法电路24，用于从语音处理电路中减去语音处理信号D2的信号电平。 电平减法电路包括输入语音处理信号的电平减法级28，其向FM调制器电路输出电平减去的语音信号，以及用于设置平均值的平均FM噪声电平设置级26 在频率调制器电路中产生的FM噪声的电平（±Esn），并将平均FM噪声电平（±Esn）输出到电平减法级。 在电平减法阶段，获得信号D2和平均FM噪声电平（±Esn）相加的信号作为电平调节语音信号，该电平调节语音信号作为调制信号被发送到 FM调制电路。 电平减法可以通过模拟或数字处理来实现。
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