公开(公告)号：US06597301B2

公开(公告)日：2003-07-22

申请号：US09970400

申请日：2001-10-03

申请人： David Cerra

发明人： David Cerra

IPC分类号： H03M112

CPC分类号： H04B1/64

摘要： Apparatus and method that mitigate the noise incurred on a wireless communications path between an encoder and a decoder of a wireless audio noise reduction system that utilizes frequency modulation (FM). The encoder includes a variable compressor that invokes compression whenever the input signal is above a first threshold level. The decoder includes a variable expander that invokes expansion whenever the received signal from the decoder is above a second threshold.

摘要翻译： 一种降低在使用频率调制（FM）的无线音频降噪系统的编码器与解码器之间的无线通信路径上产生的噪声的装置和方法。 编码器包括可变压缩器，每当输入信号高于第一阈值电平时调用压缩。 解码器包括一个可变扩展器，只要来自解码器的接收信号高于第二阈值就调用扩展。

公开(公告)号：US20030123480A1

公开(公告)日：2003-07-03

申请号：US10182523

申请日：2002-11-14

发明人： Kazuaki Maeda

IPC分类号： H04J003/16

CPC分类号： H04B1/64 ,  H03G3/001 ,  H03G3/3042

摘要： The present invention provides a digital communication system which is free from noise generated in a receiver. A transmitter converts an analog input signal to a digital signal, and then a power level detector 5 compares the digital signal with a predetermined level. In accordance with the result, the transmitter transmits a transmission signal which includes the digital signal or a digital signal amplified from that digital signal, and a control bit indicative of the result of comparison. The receiver, in accordance with the control bit included in the received digital signal, outputs an analog signal converted from the received digital signal or an analog signal converted from the received digital signal after it is digitally amplified.

摘要翻译： 本发明提供了一种没有在接收机中产生的噪声的数字通信系统。 发射机将模拟输入信号转换为数字信号，然后功率电平检测器5将数字信号与预定电平进行比较。 根据结果​​，发射机发射包括数字信号的发射信号或从该数字信号放大的数字信号，以及表示比较结果的控制位。 接收机根据接收的数字信号中包含的控制位，输出从接收的数字信号转换的模拟信号或在接收数字信号经数字放大后从所接收的数字信号转换的模拟信号。

公开(公告)号：US5901348A

公开(公告)日：1999-05-04

申请号：US782545

申请日：1997-01-10

申请人： William R. Bang ,  Peter J. Burke ,  Joseph S. Levy

发明人： William R. Bang ,  Peter J. Burke ,  Joseph S. Levy

IPC分类号： G01S7/35 ,  H04B1/64 ,  H04B1/16

CPC分类号： H04B1/64 ,  G01S7/354

摘要： A continuous wave (CW) integrator is employed within a compressive receiver to improve the sensitivity of the compressive receiver to CW signals. The CW integrator circuit partitions the bandwidth of the compressive receiver into a series of contiguous bins and integrates any signals residing within these bins over many sweeps of the compressive receiver bandwidth. By sampling and integrating CW signals present in the compressive receiver bandwidth, the CW integrator circuit improves the sensitivity of the compressive receiver by a factor approximately equal to 10 log .sqroot.N, where N is the number of integrations performed.

摘要翻译： 在压缩接收机内采用连续波（CW）积分器来提高压缩接收机对CW信号的灵敏度。 CW积分器电路将压缩接收机的带宽划分成一系列连续的存储区，并将驻留在这些存储区内的任何信号整合到多个压缩接收机带宽的扫描中。 通过对存在于压缩接收机带宽中的CW信号进行采样和积分，CW积分器电路将压缩接收机的灵敏度提高约10 log 2ROOT + E，rad N + EE，其中N是执行的积分次数。

公开(公告)号：US5631648A

公开(公告)日：1997-05-20

申请号：US353615

申请日：1994-12-12

申请人： Takaaki Yamada ,  Kazuo Kumano ,  Kazuhiro Takeda

发明人： Takaaki Yamada ,  Kazuo Kumano ,  Kazuhiro Takeda

IPC分类号： H03G7/08 ,  H03G7/00 ,  H03G11/00 ,  H04B1/64 ,  H03M1/88

CPC分类号： H04B1/64

摘要： A signal-processing circuit adapted for signal compression and expansion performed in the transmitter and receiver of mobile communication equipment. The signal-processing circuit comprises a multiplication type D/A converter to which an analog signal is applied, a level detector circuit that detects the level of the analog signal, and an A/D converter. The D/A converter converts the analog input signal into an analog output signal having an amplitude corresponding to digital control data. The A/D converter digitizes the output signal from the level detector circuit and supplies it as said digital control data to the D/A converter. These circuits can be fabricated from CMOS circuits.

摘要翻译： 一种适于在移动通信设备的发射机和接收机中执行的信号压缩和扩展的信号处理电路。 该信号处理电路包括一个乘法型D / A转换器，一个模拟信号被施加到其上，一个电平检测电路检测模拟信号的电平，一个A / D转换器。 D / A转换器将模拟输入信号转换成具有对应于数字控制数据的振幅的模拟输出信号。 A / D转换器对来自电平检测器电路的输出信号进行数字化，并将其作为数字控制数据提供给D / A转换器。 这些电路可以由CMOS电路制造。

公开(公告)号：US5179361A

公开(公告)日：1993-01-12

申请号：US700279

申请日：1991-05-15

申请人： Nasrollah S. Navid ,  Michael J. DeLurio

发明人： Nasrollah S. Navid ,  Michael J. DeLurio

IPC分类号： H04B1/64

CPC分类号： H04B1/64

摘要： A compandor system is provided that uses integrated circuitry in combination with fully external controlling devices for unity gain level adjustment without affecting the dynamic range. In addition, the system's stability is maintained. The external control is provided, for instance, by replaceable discrete resistors.

摘要翻译： 提供了一种使用集成电路与完全外部控制器件进行单位增益电平调整而不影响动态范围的压缩器系统。 另外还保持了系统的稳定性。 外部控制例如由可替换的分立电阻器提供。

公开(公告)号：US5065451A

公开(公告)日：1991-11-12

申请号：US363863

申请日：1989-06-09

申请人： Howard Leveque

发明人： Howard Leveque

IPC分类号： H04B14/00 ,  H04B1/64

CPC分类号： H04B1/64

摘要： A linked compressor-expander (Lincompex) circuit for use in telecommunications utilizes a frequency compensation circuit to frequency shift the total bandwidth of the whole communication channel to eliminate single side band "duck-talk" and data distortion in the transmitting of a complex waveform due to frequency drift or the detuning of the transmitter/receiver system. The demodulator includes an expander for expanding the compressed voice or data signal and a control tone conversion circuit for converting the received control tone into a frequency signal to be used by the expander. The control tone conversion circuit also determines the frequency error of a combination information waveform so that the frequency compensation circuit can carry out the proper frequency shifting process. A fading regulator is also provided to remove any audible level variations not removed by the automatic gain control circuitry in the receiver.

公开(公告)号：US4894862A

公开(公告)日：1990-01-16

申请号：US222432

申请日：1988-07-19

申请人： Bruno Defretin ,  Thierry Arnaud

发明人： Bruno Defretin ,  Thierry Arnaud

IPC分类号： H03G7/00 ,  H03M7/30 ,  H04B1/64 ,  H04M1/60

CPC分类号： H04B1/64 ,  H03G7/002 ,  H04M1/6033

摘要： The Invention relates to a signal compression circuit, more particularly for a telephone set of the handsfree-type, comprising a preamplifier (10), the input of which is connected with an input signal to be processed, and a preamplifier gain control device (11) for servo-controlling, to a predetermined value, the output signal amplitude of the preamplifier, in which the gain control device (11) is associated with a circuit (C, 15, 16) determining two time constants, which respectively control the increase or decrease speed of the preamplifier gain (10) in relation with the input signal amplitude (Vin).

摘要翻译： 本发明涉及一种信号压缩电路，更具体地说，涉及一种免提型电话机，包括前置放大器（10），其输入端与要处理的输入信号相连，以及前置放大器增益控制装置（11 ），用于伺服控制预定值，其中增益控制装置（11）与确定两个时间常数的电路（C，15,16）相关联的前置放大器的输出信号幅度，其分别控制增加 或相对于输入信号幅度（Vin）降低前置放大器增益（10）的速度。

公开(公告)号：US4573208A

公开(公告)日：1986-02-25

申请号：US558046

申请日：1984-01-26

申请人： Paul H. Jacobs ,  Douglas P. Collette

发明人： Paul H. Jacobs ,  Douglas P. Collette

IPC分类号： H04B1/64 ,  H04B1/68 ,  H04B1/76 ,  H04B7/00

CPC分类号： H04B1/64 ,  H04B1/68

摘要： A compressed single side band communication system and method in which the audio signal is compressed prior to pre-emphasis and thereafter summed with a pilot tone for further compression prior to transmission. Initially, only the pilot tone is transmitted at full rated power to aid in acquisition of the signal by the receiver. Thereafter, the transmitter ALC is disabled and the pilot tone is attenuated. The receiver adjusts the frequency characteristics of the pilot tone filter and phase lock loop filter in the detector as a function of lock-on. The delay after loss of lock-on in reverting to wide band pilot tone and wideband loop filters is varied as a function of signal strength. The pilot tone may be modulated for tone coded squelch. The modulating source is located in the return end of the phase lock loop filter. A unique filter is provided to insure acquisition of the pilot tone. Automatic gain control of the audio signal is responsive to the tone signal without affecting the composite audio and tone signal.

摘要翻译： 一种压缩单边带通信系统和方法，其中音频信号在预加重之前被压缩，然后在传输之前与用于进一步压缩的导频音相加。 最初，只有导频音以全额定功率传输，以帮助接收机获取信号。 此后，发射机ALC被禁用并且导频音被衰减。 接收机调节检测器中导频音滤波器和锁相环滤波器的频率特性，作为锁定功能。 作为信号强度的函数，响应于宽带导频和宽带环路滤波器的锁定失去锁定之后的延迟是变化的。 可以对导频音进行调制，进行音调编码的静噪。 调制源位于锁相环滤波器的返回端。 提供一个唯一的滤波器来确保采集导频音。 音频信号的自动增益控制响应于音调信号而不影响复合音频和音调信号。

公开(公告)号：US4562571A

公开(公告)日：1985-12-31

申请号：US558888

申请日：1983-12-07

申请人： Pierre Deman ,  Jean Potage

发明人： Pierre Deman ,  Jean Potage

IPC分类号： H04B1/64 ,  H04B3/20

CPC分类号： H04B1/64

摘要： The device is of the type comprising a circuit for compressing the dynamic of the speech signal before transmission of the signal at constant level and an expander for re-establishing at reception the speech level before compression thereof. A logic filtering circuit controls the compression circuit by constant attenuation steps depending on the speech level. A selector comparator circuit coupled by a first input to an output of the logic filtering circuit and by a second input to the output of a device controlling the expander compares the attenuation values supplied by the logic filtering circuit with those supplied by the device controlling the expander and adjusts the attenuation value of the compression circuit to the greatest of the attenuation values supplied by the logic filtering circuit or by the control device of the expander.

摘要翻译： 该装置的类型包括用于在传输恒定电平的信号之前压缩语音信号的动态的电路和用于在接收压缩之前在接收处重新建立语音电平的扩展器。 逻辑滤波电路根据语音电平通过恒定的衰减步骤控制压缩电路。 通过第一输入耦合到逻辑滤波电路的输出并通过第二输入耦合到控制扩展器的器件的输出的选择器比较器电路将由逻辑滤波电路提供的衰减值与由控制扩展器的器件提供的衰减值进行比较 并且将压缩电路的衰减值调整到由逻辑滤波电路或扩展器的控制装置提供的最大衰减值。

公开(公告)号：US4485483A

公开(公告)日：1984-11-27

申请号：US476738

申请日：1983-03-18

申请人： Emil L. Torick ,  Thomas B. Keller

发明人： Emil L. Torick ,  Thomas B. Keller

IPC分类号： H03G7/00 ,  H04B1/64 ,  H04H20060101 ,  H04H1/00 ,  H04H20/48 ,  H04H20/88 ,  H04H5/00

CPC分类号： H04H20/48 ,  H03G7/00 ,  H04B1/64

摘要： An FM stereophonic radio broadcasting system in which stereophonically related audio frequency source signals L and R are matrixed to obtain stereophonic sum and difference signals M and S, respectively. At the transmitter, the difference signal, is compressed, and the conventional difference signal and the compressed difference signal modulate respective quadrature-related sub-carriers of the same frequency to develop two double-sideband, suppressed-carrier signals, the frequency of the sub-carriers being sufficiently high as to assure a frequency gap between the lower sidebands of the modulated sub-carrier signals and the sum signal M. The M signal, the aforementioned suppressed-carrier signals, and a pilot signal having a frequency which lies within the frequency gap, are combined and frequency-modulated onto a high frequency carrier for the purpose of transmitting the same to one or more remote receivers. The receiver includes an expander for complementarily expanding the received compressed difference signal, and the expanded noise-reduced difference signal is combined with the received sum signal to reproduce the audio frequency source signals L and R. The system increases the broadcast coverage area over that of current biphonic service yet is compatible with existing monophonic and biphonic receivers.

摘要翻译： 立体声相关的音频源信号L和R被矩阵化的FM立体声无线电广播系统分别获得立体声和差分信号M和S。 在发射机处，差分信号被压缩，并且传统的差分信号和压缩的差分信号调制相同频率的各个正交相关子载波以产生两个双边带，抑制载波信号，子频率 载波足够高以确保调制的子载波信号的下边带与和信号M之间的频率间隙.M信号，前述的抑制载波信号和具有位于该信号中的频率的导频信号 频率间隙被组合和频率调制到高频载波上，以将其发送到一个或多个远程接收机。 接收机包括用于互补地扩展接收的压缩差分信号的扩展器，并且扩展的降噪差信号与接收到的和信号相组合，以再现音频源信号L和R.系统增加广播覆盖区域超过 目前的双声道服务与现有的单声道和双声道接收机兼容。