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公开(公告)号：US09680435B1
公开(公告)日：2017-06-13
申请号：US15257418
申请日：2016-09-06
Applicant: Beken Corporation
Inventor： Yiming Huang , Weifeng Wang
CPC classification number: H03G3/3005 , H03G3/3052 , H03G3/3068 , H03M1/124 , H04L27/08
Abstract: A method for improving acoustics of amplitude modulation (AM) audio signal, comprising: amplifying and mixing, with an amplitude modulation (AM) front-end module, an analog AM signal and an automatic gain control (AGC) signal from an AGC module; converting and sampling, with an analog-digital converter and down-sampling module, the amplified and mixed signal to generate a digital AM signal; digitally mixing, with a digital mixer module, the digital AM signal to generate a first digital AM envelope signal; compensating, with an AM compensator module, the first digital AM envelope signal by an AM compensating AGC signal from the AM compensator module to generate a second digital AM envelope signal; demodulating, with a demodulation module, the second digital AM envelope signal; and outputting, with an output module, a demodulated AM audio signal.
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公开(公告)号：US07639821B2
公开(公告)日：2009-12-29
申请号：US11031121
申请日：2005-01-06
Applicant: Richard L. Zinser
Inventor： Richard L. Zinser
IPC: H04H20/49
CPC classification number: H04B1/30 , H03D1/2245
Abstract: A software defined radio detects an amplitude modulated (AM) signal contained within a received signal. This detection involves first receiving a radio frequency (RF) signal that contains the AM signal modulated about a carrier frequency (fc). The RF signal is downconverted using a first local oscillator having a frequency flo. An in-phase (I) channel signal and a quadrature (Q) channel signal are produced. From the I-channel signal, a relationship between the carrier frequency and the frequency of the local oscillator is determined with a frequency detector. The downconverted carrier signal of the I-channel signal is used to create a second set of signals with proper phases and frequencies that can be used to rotate the I-channel and Q-channel signals to account for differences between the downconverted fc and DC. From the I-channel and Q-channel signals, a phase difference between the I-channel and Q-channel signals is determined so that the processed I-channel and Q-channel signals can be properly combined. Properly combining the processed (rotated) I-channel and Q-channel signals results in a demodulated AM signal.
Abstract translation: 软件定义的无线电装置检测包含在接收信号内的调幅（AM）信号。 该检测涉及首先接收包含关于载波频率（fc）调制的AM信号的射频（RF）信号。 RF信号使用具有频率flo的第一本地振荡器进行下变频。 产生同相（I）信道信号和正交（Q）信道信号。 从I信道信号中，使用频率检测器确定载波频率与本地振荡器的频率之间的关系。 I信道信号的下变频载波信号用于产生具有适当相位和频率的第二组信号，其可用于旋转I信道和Q信道信号以解决下变频的fc和DC之间的差异。 从I信道和Q信道信号，确定I信道和Q信道信号之间的相位差，使得可以适当地组合经处理的I信道和Q信道信号。 正确组合经处理（旋转）I信道和Q信道信号导致解调的AM信号。
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公开(公告)号：US07437299B2
公开(公告)日：2008-10-14
申请号：US10510219
申请日：2003-03-20
Applicant: Ronaldus Maria Aarts , Roy Irwan
Inventor： Ronaldus Maria Aarts , Roy Irwan
CPC classification number: G10L19/008 , H04B1/667
Abstract: A method of encoding a multichannel signal, such as a stereophonic audio signal, including at least first and second signal components includes transforming at least the first and second signal components by a predetermined transformation into a principal signal including most of the signal energy and at least one residual signal including less energy than the principal signal. The predetermined transformation is parameterized by at least one transformation parameter. The method further includes representing the multichannel signal at least by the principal signal and the transformation parameter.
Abstract translation: 编码包括至少第一和第二信号分量的立体声音频信号的多声道信号的方法包括将至少第一和第二信号分量通过预定变换变换成包括大部分信号能量的主信号，并且至少 一个残余信号包括比主信号更少的能量。 通过至少一个变换参数对预定的变换进行参数化。 该方法还包括至少由主信号和变换参数表示多信道信号。
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公开(公告)号：US5014316A
公开(公告)日：1991-05-07
申请号：US500837
申请日：1990-03-21
Applicant: Jeffrey J. Marrah , Gregory J. Manlove , Richard A. Kennedy
Inventor： Jeffrey J. Marrah , Gregory J. Manlove , Richard A. Kennedy
CPC classification number: H04H20/49
Abstract: An audio detector circuit forms L+R and L-R audio signals from an intermediate frequency compatible quadrature amplitude modulated signal in the form (1+L+R)cos(fct+.phi.) where .phi. contains phase modulated L+R and L-R signals. An envelope detector generates an L+R audio signal and in-phase and quadrature phase detectors produce L+R and L-R audio signals, respectively. The difference between L+R outputs of the envelope and in-phase detectors are amplified to generate a cosine correction signal. Each detector includes a differential operational amplifier having an field effect feedback transistor coupled between each amplifier output and the corresponding input and an field effect transistor coupling the compatible quadrature amplitude modulated signal to the operational amplifier inputs. The impedances presented by the feedback transistor are varied by the cosine correction signal to remove the cosine component of the compatible quadrature amplitude modulated signal while frequency multiplication at the IF frequency rate provides the correct phase audio signal for matrix and noise processing.
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公开(公告)号：US4688254A
公开(公告)日：1987-08-18
申请号：US846775
申请日：1986-04-01
Applicant: Lawrence M. Ecklund
Inventor： Lawrence M. Ecklund
CPC classification number: H04H20/49
Abstract: A control circuit in an AM stereophonic receiver examines a detected signal for occurrences of overmodulation and, when a first given level of overmodulation is reached, begins to turn down the correction signal used in the demodulation and, if overmodulation continues, would eventually eliminate the correction signal. At a second given level of overmodulation, the circuit will begin to attenuate the stereo difference signal from the receiver output and eventually eliminate it. When the overmodulation is reduced, operating conditions return toward normal.
Abstract translation: AM立体声接收机中的控制电路检查用于出现过调制的检测信号，并且当达到第一给定电平的过调制时，开始降低在解调中使用的校正信号，并且如果继续过调制将最终消除校正 信号。 在第二给定的过调制电平时，电路将开始衰减来自接收器输出的立体声差分信号，并最终消除它。 当过调制减少时，操作条件恢复正常。
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Patent Agency Ranking
公开(公告)号：US4680795A
公开(公告)日：1987-07-14
申请号：US812687
申请日：1985-12-23
Applicant: Lawrence M. Ecklund
Inventor： Lawrence M. Ecklund
CPC classification number: H04H20/49 , H03H11/1291
Abstract: A variable Q filter network in an AM stereophonic receiver provides elimination of any adjacent channel carrier interference while providing the function of a tone control, either automatic or manually controlled. Parts count and costs, IC pinouts and the possibility of intermodulation are all reduced.
Abstract translation: AM立体声接收机中的可变Q滤波器网络提供消除任何相邻信道载波干扰，同时提供自动或手动控制的音调控制的功能。 零件数量和成本，IC引脚分配和互调的可能性都减少了。
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公开(公告)号：US4653095A
公开(公告)日：1987-03-24
申请号：US826717
申请日：1986-02-06
Applicant: Leonard R. Kahn
Inventor： Leonard R. Kahn
CPC classification number: H04H20/49
Abstract: Certain, but not all AM stereo radio broadcasting and reception systems suffer from a severe form of reception anomaly wherein the perceived stereo image moves from side to side, back and forth, which effect has come to be known as "Stereo Platform Motion" or simply "Platform Motion". A prior art patent proposed a method for sensing reception conditions conductive to Platform Motion and then switching the receiver from stereo to monophonic reception to avoid Platform Motion. The present invention enables the AM stereo receiver to maintain stereo operation under such reception conditions, and instead of switching the receiver to monophonic operation, it switches the receiver to a different method of stereo reception that does not suffer from Platform Motion.
Abstract translation: 某些但不是全部的AM立体声无线电广播和接收系统遭受严重形式的接收异常，其中感知的立体声图像从一侧到另一侧来回移动，这种效果已经被称为“立体声平台运动”或简单地 “平台运动”。 现有技术专利提出了一种用于感测对平台运动传导的接收条件，然后将接收机从立体声切换到单声道接收以避免平台运动的方法。 本发明使AM立体声接收机能够在这种接收条件下保持立体声操作，而不是将接收机切换到单声道操作，它将接收机切换成不受平台运动影响的立体声接收的不同方法。
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公开(公告)号：US4618981A
公开(公告)日：1986-10-21
申请号：US706583
申请日：1985-02-28
Applicant: Lawrence M. Ecklund
Inventor： Lawrence M. Ecklund
Abstract: The tone detector provides accurate detection of a single predetermined tone frequency within a mixture of frequencies, utilizing a carrier signal source at a relatively high frequency. The high frequency signal is divided down to two frequencies, one just above and one just below the tone. The divider output is then maintained at the frequency of the tone by continuously adjusting the divisor number between the two divisor values. Multiplying the received signal or a portion thereof by the divider output provides a detect signal when the tone is present in the received signal with sufficient amplitude.
Abstract translation: 音调检测器利用相对较高频率的载波信号源来提供频率混合内的单个预定音调频率的精确检测。 高频信号被分为两个频率，一个刚刚在上面，一个刚好在音调之下。 然后通过连续调整两个除数值之间的除数，将除法器输出保持在音调的频率。 当接收到的信号或其一部分乘以分频器输出时，当音频以足够的幅度存在于接收信号中时，提供检测信号。
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公开(公告)号：US4580284A
公开(公告)日：1986-04-01
申请号：US621283
申请日：1984-06-15
Applicant: Lawrence M. Ecklund , Charles J. Marik
Inventor： Lawrence M. Ecklund , Charles J. Marik
CPC classification number: H04H20/49
Abstract: In an AM stereo system wherein a low frequency pilot tone is added to the difference channel signal before modulation of the carrier, "image shifting" and audio distortion in a receiver, due to residual pilot tone signal, are removed by separating out a portion of the pilot tone after it has been filtered and phase shifed for enabling the stereo mode of operation. The separated signal is then inverted and delayed appropriately for each of the PLL and audio circuits.
Abstract translation: 在AM调制立体声系统中，其中在调制载波之前将低频导频信号加到差分信道信号上，由于残余导频音信号，接收机中的“图像移位”和音频失真被分离出一部分 经过滤波和相位移后的导频音使得立体声操作模式成为可能。 然后对于每个PLL和音频电路，分离的信号被反相和适当地延迟。
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公开(公告)号：US4536885A
公开(公告)日：1985-08-20
申请号：US565303
申请日：1983-12-27
Applicant: Bernard D. Loughlin
Inventor： Bernard D. Loughlin
CPC classification number: H04H20/49 , H03G3/3073
Abstract: In a receiver for composite amplitude and angle modulated signals and having a non-flat automatic gain control characteristic, there is provided apparatus for providing distortion correction to the quadrature component produced by the angular modulation in accordance with the amplitude modulation component. In accordance with the invention, the output of an amplitude demodulator is modified to remove the carrier signal level dependent magnitude multiplier and develop a modification signal which is used to inversely amplitude modulate the quadrature signal component to provide distortion correction over a range of carrier signal levels. Such inverse modulation can be provided before or after quadrature demodulation of the received signal.
Abstract translation: 在用于复合幅度和角度调制信号并且具有非平坦自动增益控制特性的接收机中，提供了用于根据调幅分量为由角度调制产生的正交分量提供失真校正的装置。 根据本发明，修改幅度解调器的输出以去除载波信号电平相关幅度乘法器并产生修正信号，该修改信号用于对正交信号分量进行逆幅度调制，以在载波信号电平范围内提供失真校正 。 可以在接收信号的正交解调之前或之后提供这种逆调制。
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