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1.发明授权Audio magnetic recording and/or reproducing apparatus utilizing frequency modulation 失效利用频率调制的音频磁记录和/或再现装置
公开(公告)号：US4698693A
公开(公告)日：1987-10-06
申请号：US727757
申请日：1985-04-26
摘要： A rotary head type magnetic recording and reproducing apparatus comprises a circuit for recording and reproducing a signal on and from a magnetic recording medium by rotary heads, a circuit for obtaining a frequency modulated (FM) audio signal by frequency-modulating a carrier by an audio signal which is to be recorded, a circuit for generating a frequency drift detection signal having a constant frequency which does not exist within a frequency range occupied by the FM audio signal, a circuit for obtaining a frequency multiplexed signal by frequency-multiplexing the FM audio signal and the detection signal, a circuit for separating the FM audio signal and the detection signal from the signal reproduced by the rotary heads, a demodulating circuit for obtaining an audio signal by frequency-demodulating the separated FM audio signal, a detecting circuit for frequency-demodulating the separated detection signal and for detecting a frequency drift component, a circuit for forming a frequency drift correction signal responsive to the output of the detecting circuit, and a circuit for correcting a frequency drift component in the output audio signal of the demodulating circuit by the correction signal.
摘要翻译： 一种旋转磁头式磁记录和重放装置包括用于通过旋转磁头记录和再现来自磁记录介质的信号的电路，用于通过音频对载波进行频率调制来获得调频（FM）音频信号的电路 要被记录的信号，用于产生频率偏移检测信号的电路，该频率漂移检测信号具有在FM音频信号所占据的频率范围内不存在的恒定频率，用于通过对FM音频进行频率复用来获得频率复用信号的电路 信号和检测信号，用于将FM音频信号和检测信号与由旋转磁头再现的信号分离的电路，用于通过频率解调分离的FM音频信号来获得音频信号的解调电路，用于频率的检测电路 - 分离检测信号和检测频率漂移分量，形成频率的电路 响应于检测电路的输出的循环漂移校正信号，以及用于通过校正信号校正解调电路的输出音频信号中的频率漂移分量的电路。
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2.发明授权Noise reduction by linear interpolation using a dual function amplifier circuit 失效使用双功能放大器电路进行线性插值降噪
公开(公告)号：US4577161A
公开(公告)日：1986-03-18
申请号：US638779
申请日：1984-08-08
CPC分类号： H03G3/345
摘要： In a noise reduction circuit, a sampling pulse is generated for opening a switch in time-coincident relationship with a signal portion which is affected by a noise impulse. During tracking modes the signal is passed through the switch to a junction between a capacitor and a noninverting amplifier to charge the capacitor to the level of the signal. During a sampling mode the switch is open to block the signal. A feedback circuit having plural time constant values is connected between the output and input of the amplifier to provide primary and secondary differentiation of the output signal of the amplifier. The feedback circuit is disabled during tracking modes to enable the amplifier to linearly amplify the voltage developed across the capacitor and is enabled during the sampling mode to differentiate the voltage that occurred immediately before the switch is turned off for application to the input of the amplifier for linearly interpolating the noise-affected portion of the signal.
摘要翻译： 在降噪电路中，产生与受噪声冲击影响的信号部分以时间重合的关系来打开开关的采样脉冲。 在跟踪模式期间，信号通过开关传递到电容器和非反相放大器之间的接点，以将电容器充电到信号的电平。 在采样模式下，开关打开以阻止信号。 具有多个时间常数值的反馈电路连接在放大器的输出和输入之间，以提供放大器的输出信号的初级和次级差分。 在跟踪模式期间，反馈电路被禁用，以使放大器能够线性放大电容器两端产生的电压，并在采样模式期间使能，以区分开关截止前发生的电压，以应用于放大器的输入端 线性内插信号的噪声影响部分。
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3.发明授权Noise reduction by linear interpolation using a dual function amplifier circuit 失效使用双功能放大器电路进行线性插值降噪
公开(公告)号：US4539527A
公开(公告)日：1985-09-03
申请号：US635352
申请日：1984-07-27
CPC分类号： H03G3/345
摘要： In a noise reduction circuit, a sampling pulse is generated for operating a switch in time-coincident relationship with the portion of a signal which is affected by a noise impulse. The signal, applied to an input terminal, is normally passed through the switch to a junction between a capacitor and a noninverting amplifier and is blocked when the switch opens in response to the sampling pulse. A differentiator is connected in a feedback circuit from the output of the noninverting amplifier to the input thereof. The differentiator is disabled when the switch remains closed and when the switch opens in response to the sampling pulse it begins differentiating a voltage which occurred immediately prior to the detection of the noise and supplies it to the capacitor to linearly interpolate the portion of the information signal which is disrupted by the noise impulse.
摘要翻译： 在降噪电路中，产生用于与受噪声冲击影响的信号的时间重合关系操作开关的采样脉冲。 施加到输入端子的信号通常通过开关到电容器和非反相放大器之间的接点，并且当开关响应采样脉冲而断开时被阻塞。 微分器连接在反相电路中，从非反相放大器的输出到其输入端。 当开关保持闭合时，微分器被禁用，并且当开关响应于采样脉冲而断开时，微分器开始区分紧接在噪声检测之前发生的电压，并将其提供给电容器以线性内插信息信号的一部分 这被噪音冲动所打扰。
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公开(公告)号：US4614910A
公开(公告)日：1986-09-30
申请号：US757847
申请日：1985-07-22
IPC分类号： H04L27/00 , H04L27/18 , H04L27/227 , H04L27/22
CPC分类号： H04L27/2273 , H04L2027/0048 , H04L2027/0067 , H04L2027/0073
摘要： In a quarternary differential PSK demodulator, a QPSK input signal is applied to first and second synchronous detectors to which carriers with a 90-degree phase difference therebetween are respectively applied from a voltage-controlled oscillator. A first double-balanced phase detector multiplies the outputs from the synchronous detectors. A second phase detector squares the output of the second synchronous detector. A third double-balanced phase detector provides multiplication of the outputs of the first and second double-balanced phase detectors to generate an output having four times the frequency of the outputs of the synchronous detectors to cancel the information carried by the input PSK signal. A loop filter converts the output of the third phase detector to a DC phase control signal to be applied to the voltage-controlled oscillator.
摘要翻译： 在四分之一差分PSK解调器中，将QPSK输入信号施加到第一和第二同步检测器，分别从压控振荡器施加90度相位差的载波。 第一个双平衡相位检测器将来自同步检测器的输出相乘。 第二相位检测器对第二同步检波器的输出进行平方。 第三双平衡相位检测器提供第一和第二双平衡相位检测器的输出的相乘以产生具有同步检测器的输出的四倍的输出的输出，以消除由输入的PSK信号携带的信息。 环路滤波器将第三相位检测器的输出转换为施加到压控振荡器的DC相位控制信号。
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5.发明授权Impulse noise reduction by linear interpolation having a deemphasis characteristic 失效通过具有去加重特性的线性插值的脉冲噪声降低
公开(公告)号：US4532475A
公开(公告)日：1985-07-30
申请号：US585925
申请日：1984-03-02
CPC分类号： H03G3/345
摘要： An analog audio signal having a high frequency preemphasis is applied to a sampling pulse generator (2) which generates a sampling pulse in response to an impulse noise introduced to the signal and also to a sample-hold and deemphasis circuit (5; 50) which deemphasizes the audio signal when impulse noise is nonexistent and holds the signal in the presence of the sampling pulse. A differentiator (6) derives a signal representative of the slope ratio of the analog signal from the deemphasized signal. A sample-and-hold circuit (7) samples the slope ratio signal in response to the sampling pulse and applies it to a charging and discharging circuit (8; 503) which performs linear charging and discharging of the capacitor (55; 505) at a rate variable as a function of the sampled signal to reconstruct the portion of the signal lost during the sampling period.
摘要翻译： 具有高频预加重的模拟音频信号被施加到采样脉冲发生器（2），采样脉冲发生器（2）响应于引入信号的脉冲噪声以及采样保持和去加重电路（5; 50）产生采样脉冲， 当脉冲噪声不存在时，对音频信号进行强调，并在采样脉冲存在的情况下保持信号。 微分器（6）导出代表来自去加重信号的模拟信号的斜率比的信号。 采样保持电路（7）响应于采样脉冲对斜率比信号进行采样，并将其施加到充电和放电电路（8; 503），该充电和放电电路执行电容器（55; 505）的线性充电和放电 作为采样信号的函数的速率变量，以重构在采样周期期间丢失的信号的部分。
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6.发明授权Impulse noise reduction by linear interpolation having immunity to white noise 失效通过具有白噪声的线性插值的脉冲噪声降低
公开(公告)号：US4531095A
公开(公告)日：1985-07-23
申请号：US585926
申请日：1984-03-02
CPC分类号： H03G3/345
摘要： An analog audio signal is applied to a sampling pulse generator (2) which generates a sampling pulse in response to an impulse noise introduced to the signal and also to a first sample-and-hold circuit (5, 6, 7) which tracks the waveform of the audio signal when impulse noise is nonexistent and holds the signal in the capacitor (6) in response to the sampling pulse. A nonlinear transfer circuit (10) is provided to eliminate white noise contained in the analog signal from the first sample-and-hold circuit and feeds its output to a differentiator (11) to derive a signal representative of the slope ratio of the analog signal. A second sample-and-hold circuit (12) samples the slope ratio signal in response to the sampling pulse and applies the sampled signal to a bidirectional constant current source (8) which provides constant current charging and discharging of the capacitor (6) to linearly vary the voltage sampled by the first sample-and-hold circuit (12).
摘要翻译： 模拟音频信号被施加到采样脉冲发生器（2），该采样脉冲发生器（2）响应于引入信号的脉冲噪声以及第一采样和保持电路（5,6,7）产生采样脉冲，该采样和保持电路跟踪 当脉冲噪声不存在时，音频信号的波形，并且根据采样脉冲将信号保持在电容器（6）中。 提供非线性传输电路（10）以消除包含在来自第一采样保持电路的模拟信号中的白噪声，并将其输出馈送到微分器（11）以得到表示模拟信号的斜率比的信号 。 第二采样保持电路（12）响应于采样脉冲对斜率比信号进行采样，并将采样信号施加到双向恒流源（8），该双向恒流源提供电容器（6）的恒流充电和放电至 线性地改变由第一采样保持电路（12）采样的电压。
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7.发明授权Noise reduction for stereophonic FM signals by high-speed sampling and linear interpolation 失效通过高速采样和线性插值降低立体声FM信号
公开(公告)号：US4574390A
公开(公告)日：1986-03-04
申请号：US594683
申请日：1984-03-26
CPC分类号： H04B1/1661 , H03G3/345
摘要： In a noise reduction circuit for reception of stereophonic FM signals in which the demodulated signal is chopped at twice the pilot frequency for separation between left- and right-channel signals, the demodulated signal is sampled by a first sample-and-hold circuit in response to the output of the noise detector to store that portion of the signal which appeared immediately prior to the occurrence of an impulse noise. The demodulated signal is also sampled by a second sample-and-hold circuit at a frequency twice the pilot frequency to eliminate a noise which might arise due to the chopping of the demodulated signal. A signal is derived from the outputs of the first and second sample-and-hold circuits that indicates the slope ratio of the demodulated signal at the moment that occurred immediately prior to the impulse noise. The slope ratio signal is applied to a linear integrator to generate a compensating voltage which is summed with the signal sampled by the first sample-and-hold circuit at the level which occurred immediately prior to the occurrence of the impulse noise.
摘要翻译： 在用于接收立体声FM信号的噪声降低电路中，其中解调信号以两倍于用于分离左声道和右声道信号的导频之间的斩波，解调的信号由第一采样保持电路进行采样 到噪声检测器的输出端以存储紧接在脉冲噪声发生之前出现的那部分信号。 解调信号也由第二采样保持电路以导频频率的两倍采样，以消除由于解调信号的斩波而可能产生的噪声。 来自第一和第二采样保持电路的输出的信号是指示紧接在脉冲噪声之前发生的时刻的解调信号的斜率比。 斜率比信号被施加到线性积分器，以产生补偿电压，该补偿电压与由第一采样保持电路采样的信号相加，发生在紧接在脉冲噪声之前发生的电平。
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8.发明授权Spread spectrum modulating and demodulating apparatus for transmission and reception of FSK and PSK signals 失效用于FSK和PSK信号的发射和接收的扩频调制和解调装置
公开(公告)号：US5832027A
公开(公告)日：1998-11-03
申请号：US607560
申请日：1996-02-27
申请人： Yukinobu Ishigaki
发明人： Yukinobu Ishigaki
摘要： A spread spectrum modulating and demodulating apparatus which is capable of providing FSK or PSK spread spectrum communications. In a transmitting device an input information signal is fed either to an oscillator or to a side of a power supply which is in turn connected to an operation device. An oscillator produces a carrier frequency signal which multiplied by a multiplier by the predetermined integer N1. A frequency divider divides the frequency of the carrier by a predetermined integer N2. A spread code generator uses an output signal of the frequency divider as a clock signal, and generates a spread code which is fed to the operation device. A switch selectively feeds an input information signal to either the oscillator for frequency shift keying the oscillator or through the side of the power supply connected to the operation device will effect a phase shift key operation. A spread spectrum demodulating device additionally provides for demodulation of either a frequency shift keyed signal or a phase shift keyed signal.
摘要翻译： 一种能够提供FSK或PSK扩频通信的扩频调制解调装置。 在发送装置中，输入信息信号被馈送到振荡器或电源的一侧，该电源又连接到操作装置。 振荡器产生乘以乘数乘以预定整数N1的载波频率信号。 分频器将载波的频率除以预定的整数N 2。 扩展码发生器使用分频器的输出信号作为时钟信号，并产生馈送到操作装置的扩展码。 开关选择性地将输入信息信号馈送到振荡器以进行频移键控振荡器或通过连接到操作装置的电源侧将实现相移键操作。 扩频解调装置还提供对频移键控信号或相移键控信号的解调。
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公开(公告)号：US5170411A
公开(公告)日：1992-12-08
申请号：US762885
申请日：1991-09-19
申请人： Yukinobu Ishigaki
发明人： Yukinobu Ishigaki
IPC分类号： H04B1/12 , H04B1/707 , H04B1/7107 , H04J13/00 , H04K3/00
摘要： A modulation and demodulation system for spread spectrum transmission comprises modulation and demodulation sections. The modulation section spreads/modulates an input information signal by multiplying by a PN code to provide a spread spectrum signal. The demodulation section despreads/demodulates the spread spectrum signal including interference mixed therein by substantially using the same spread code. In the demodulation section, a first multiplier despreads the received signal by multiplying by the PN code to provide a despread demodulation signal, a high-pass filter extracts a first spread interference signal from the despread demodulation signal, a second multiplier multiplies the spread interference signal by a high-frequency range emphasized PN code, a low-pass filter attenuates high-frequency range components of the output signal of the second multiplier, a third multiplier multiplies the output signal of the low-pass filter by a high-frequency range attenuated PN code, an emphasizing circuit emphasizes low-frequency range components of the output signal of the third multiplier to provide a second spread interference signal, and a subtracter obtains the difference between the second spread interference signal and the despread demodulation signal to provide the interference-free demodulated information signal.
摘要翻译： 用于扩频传输的调制和解调系统包括调制和解调部分。 调制部分通过乘以PN码扩展/调制输入信息信号，以提供扩频信号。 解调部分通过基本上使用相同的扩展码对包括其中混入的干扰的扩频信号进行解扩/解调。 在解调部分中，第一乘法器通过乘以PN码对接收信号进行解扩，以提供解扩解调信号，高通滤波器从解扩解调信号中提取第一扩展干扰信号，第二乘法器将扩展干扰信号 通过高频范围强调的PN码，低通滤波器衰减第二乘法器的输出信号的高频范围分量，第三乘法器将低通滤波器的输出信号乘以衰减的高频范围 PN码，强调电路强调第三乘法器的输出信号的低频范围分量，以提供第二扩展干扰信号，减法器获得第二扩展干扰信号和解扩解调信号之间的差异， 自由解调信息信号。
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公开(公告)号：US4354059A
公开(公告)日：1982-10-12
申请号：US185516
申请日：1980-09-09
摘要： A variable-directivity microphone device comprises a microphone unit having a plurality of microphones, a circuit which resultingly adds the low-frequency range components of the output signal of one of the microphones of the microphone unit and mixes with the output signal of the other microphone so that only the high-frequency range components cancel each other, and an equalizer which corrects the characteristic of the mixed signal. The above effective mixing is performed under varying mixing states.
摘要翻译： 可变方向性麦克风装置包括具有多个麦克风的麦克风单元，其结果是增加了麦克风单元之一的麦克风的输出信号的低频范围分量，并与另一麦克风的输出信号混合 使得仅高频范围分量彼此抵消，以及校正混合信号的特性的均衡器。 上述有效混合是在不同的混合状态下进行的。
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