公开(公告)号：US09380389B2

公开(公告)日：2016-06-28

申请号：US14023350

申请日：2013-09-10

Applicant: NXP B.V.

Inventor： Temujin Gautama

IPC: H04H20/48 ,  H04R5/04 ,  H04H40/72 ,  H04L25/03

CPC classification number: H04R5/04 ,  H04H40/72 ,  H04L25/03159

Abstract: The invention provides an audio signal processing system in which a magnitude spectrum of a frequency domain audio signal is processed based on a measure of multipath interference. The processing keeps the magnitude spectrum approximately fixed during periods of multipath interference, for example by replacing it with a temporally smoothed version of the magnitude spectrum. The magnitude spectrum (processed if required) and the phase spectrum are combined to derive a frequency domain output, which is transformed to the time domain.

Abstract translation: 本发明提供一种音频信号处理系统，其中基于多路径干扰的测量来处理频域音频信号的幅度谱。 该处理在多径干扰期间保持幅度谱近似固定，例如用幅度谱的时间平滑版本代替它。 幅度谱（如果需要处理）和相位频谱被组合以导出频域输出，其被转换到时域。

公开(公告)号：US20150326330A1

公开(公告)日：2015-11-12

申请号：US14699662

申请日：2015-04-29

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC ,  KATHREIN AUTOMOTIVE NORTH AMERICA, INC.

Inventor： TIMOTHY J. TALTY ,  GREGG R. KITTINGER ,  ANDREAS FUCHS ,  ELIAS GHAFARI

IPC: H04H40/72

CPC classification number: H04H40/72 ,  H01Q1/3208 ,  H01Q5/321 ,  H04B1/18

Abstract: An AM/FM radio system for a vehicle that is selectively impedance matched to the particular tuned frequency of interest so that noise received by other frequencies does not affect the received signal. The radio system includes an HMI allowing a user to select an AM or FM radio station and a radio tuner responsive to a signal from the HMI identifying the selected radio station. The tuner tunes the radio system to the radio station, and provides a signal to the HMI identifying the radio station. The HMI places a message on a vehicle bus identifying the radio station that the radio tuner is tuned to. An antenna controller receives the message from the vehicle bus to selectively control an impedance matrix to provide impedance matching for the selected radio station frequency. The antenna controller also selectively tunes antenna radiating elements to the particular tuned frequency.

Abstract translation: 用于车辆的AM / FM无线电系统，其选择性地阻抗匹配于感兴趣的特定调谐频率，使得由其他频率接收的噪声不影响接收的信号。 无线电系统包括允许用户选择AM或FM无线电台的HMI，以及响应于来自HMI的信号识别所选择的无线电台的无线电调谐器。 调谐器将无线电系统调谐到无线电台，并向HMI识别广播电台提供信号。 HMI在车辆总线上放置一条消息，标识无线电调谐器调谐到的无线电台。 天线控制器从车辆总线接收消息以选择性地控制阻抗矩阵以提供所选无线电台频率的阻抗匹配。 天线控制器还选择性地将天线辐射元件调谐到特定的调谐频率。

公开(公告)号：US20140348328A1

公开(公告)日：2014-11-27

申请号：US13899868

申请日：2013-05-22

Applicant: Pankaj Gupta ,  Sriram Murali ,  Jaiganesh Balakrishnan ,  Sanjay Vishwakarma

Inventor： Pankaj Gupta ,  Sriram Murali ,  Jaiganesh Balakrishnan ,  Sanjay Vishwakarma

IPC: H04H60/58

CPC classification number: H04H60/58 ,  H04B1/1646 ,  H04H40/45 ,  H04H40/72 ,  H04H40/81

Abstract: Several circuits and methods implemented to perform signal quality estimation and control are disclosed. In an embodiment, a method of signal quality estimation includes generating a demodulated signal associated with a radio signal. Information associated with a quality of the demodulated signal is accessed. Further, a value of radio frequency signal-to-noise ratio (RF-SNR) for the radio signal based on the information is estimated. Estimating the value of RF-SNR facilitates in signal quality estimation of the radio signal and control of the demodulated signal.

Abstract translation: 公开了执行信号质量估计和控制的几种电路和方法。 在一个实施例中，信号质量估计的方法包括产生与无线电信号相关联的解调信号。 访问与解调信号的质量相关的信息。 此外，估计基于该信息的无线电信号的射频信噪比（RF-SNR）值。 估计RF-SNR的值有助于无线电信号的信号质量估计和解调信号的控制。

公开(公告)号：US08666346B1

公开(公告)日：2014-03-04

申请号：US13594506

申请日：2012-08-24

Applicant: Sira Parasurama Rao ,  John Elliott Whitecar

Inventor： Sira Parasurama Rao ,  John Elliott Whitecar

IPC: H04B1/16

CPC classification number: H04L25/022 ,  H03D3/00 ,  H04B1/1646 ,  H04H40/72

Abstract: An FM receiver is unaware of the modulation level (frequency deviation) of the signal and has to make an estimate of it, or some reasonable time-average of it, and accordingly set the input filter's bandwidth. We calculate modulation by measuring the autocorrelation of the recovered audio signal instead of its peaks, and then applying a peakhold detector. Since FM noise can be modeled to be somewhat uncorrelated, we can expect to get an accurate estimate of signal power while rejecting noise power substantially if we measure a one-sample delayed autocorrelation estimate. Since the above measurement is alike a power measurement, we compute its square root, gain adjust it to obtain a cleaner peak measurement, and then track these clean peaks using a leaky integrator. This gives an estimate of modulation that subdues the effect of the noise.

Abstract translation: FM接收机不知道信号的调制级别（频率偏差），并且必须对其进行估计，或者对其进行一些合理的时间平均，并因此设置输入滤波器的带宽。 我们通过测量恢复的音频信号的自相关而不是其峰值来计算调制，然后应用峰值检测器。 由于FM噪声可以被模拟为有些不相关，所以如果我们测量单样本延迟自相关估计值，我们可以期望获得信号功率的准确估计，同时抑制噪声功率。 由于上述测量与功率测量类似，我们计算其平方根，增益调整它以获得更干净的峰值测量，然后使用泄漏积分器跟踪这些干净的峰值。 这给出了抑制噪声影响的调制估计。

公开(公告)号：US20140057582A1

公开(公告)日：2014-02-27

申请号：US13594506

申请日：2012-08-24

Applicant: Sira Parasurama Rao ,  John Elliott Whitecar

Inventor： Sira Parasurama Rao ,  John Elliott Whitecar

IPC: H04L25/02

CPC classification number: H04L25/022 ,  H03D3/00 ,  H04B1/1646 ,  H04H40/72

Abstract: An FM receiver is unaware of the modulation level (frequency deviation) of the signal and has to make an estimate of it, or some reasonable time-average of it, and accordingly set the input filter's bandwidth. We calculate modulation by measuring the autocorrelation of the recovered audio signal instead of its peaks, and then applying a peakhold detector. Since FM noise can be modeled to be somewhat uncorrelated, we can expect to get an accurate estimate of signal power while rejecting noise power substantially if we measure a one-sample delayed autocorrelation estimate. Since the above measurement is alike a power measurement, we compute its square root, gain adjust it to obtain a cleaner peak measurement, and then track these clean peaks using a leaky integrator. This gives an estimate of modulation that subdues the effect of the noise.

Abstract translation: FM接收机不知道信号的调制级别（频率偏差），并且必须对其进行估计，或者对其进行一些合理的时间平均，并因此设置输入滤波器的带宽。 我们通过测量恢复的音频信号的自相关而不是其峰值来计算调制，然后应用峰值检测器。 由于FM噪声可以被模拟为有些不相关，所以如果我们测量单样本延迟自相关估计值，我们可以期望获得信号功率的准确估计，同时抑制噪声功率。 由于上述测量与功率测量类似，我们计算其平方根，增益调整它以获得更干净的峰值测量，然后使用泄漏积分器跟踪这些干净的峰值。 这给出了抑制噪声影响的调制估计。

公开(公告)号：US20130182851A1

公开(公告)日：2013-07-18

申请号：US13736363

申请日：2013-01-08

Applicant: NXP B.V.

Inventor： Temujin GAUTAMA

IPC: H04H20/89

CPC classification number: H04H20/89 ,  H04B1/1676 ,  H04H40/72

Abstract: A processing unit for processing a multi-channel audio signal has a delay element (40) for delaying an FM sum signal (sum) and a converter arrangement (T) for converting an FM difference signal (duff) and a noise signal (diffnoise) to the frequency domain. Frequency-based noise suppression is used to derive a de-noised frequency-domain difference signal using a gain function which is limited to a maximal and a minimal value. This is then converted to the time domain, and the first and second audio signals are calculated from a delayed sum signal (sum2) and the de-noised time domain difference signal (diff2).

Abstract translation: 用于处理多声道音频信号的处理单元具有用于延迟FM和信号（sum）的延迟元件（40）和用于转换FM差分信号（duff）和噪声信号（diffnoise）的转换器装置（T） 到频域。 使用基于频率的噪声抑制来使用限于最大和最小值的增益函数来导出去噪的频域差分信号。 然后将其转换为时域，并且从延迟和信号（sum2）和去噪时间域差信号（diff2）计算第一和第二音频信号。

公开(公告)号：US08081942B1

公开(公告)日：2011-12-20

申请号：US12152675

申请日：2008-05-14

Applicant: Chris Cheng-Chieh Lee

Inventor： Chris Cheng-Chieh Lee

IPC: H04B1/16

CPC classification number: H04B1/1027 ,  H04H40/72

Abstract: A constant modulus indicator (CMI) measure is calculated for a received signal having a constant modulus component C and a noise component N. The CMI measure indicates a ratio of an energy of C to an energy of N. A determination of whether to attenuate a derived signal is made based on the CMI measure, wherein the derived signal is generated from the received signal. The derived signal is attenuated based on the determination.

Abstract translation: 对于具有恒模分量C和噪声分量N的接收信号，计算恒模指标（CMI）测量.CMI测量指示C的能量与N的能量的比。确定是否衰减 基于CMI测量进行导出信号，其中从所接收的信号产生导出的信号。 导出的信号根据确定被衰减。

公开(公告)号：US06993309B2

公开(公告)日：2006-01-31

申请号：US09949755

申请日：2001-09-12

Applicant: Masahiro Tsujishita ,  Masayuki Tsuji ,  Kenichi Taura ,  Masayuki Ishida

Inventor： Masahiro Tsujishita ,  Masayuki Tsuji ,  Kenichi Taura ,  Masayuki Ishida

IPC: H04B1/10

CPC classification number: H04H40/72 ,  H04B1/1081 ,  H04B1/1661

Abstract: A noise removal unit mounted on a car radio according to the invention removes multipath noise and pulse noise from FM demodulated signals. At this time, the noise removal unit removes all of the multipath noise. Also, in case where the generation density of noise is high, the noise removal unit reduces the detection sensitivity so as not to detect pulse noise, particularly of small level, as noise. Comparing to multipath noise, pulse noise is noise rendering a large correction error than multipath noise. Therefore, in case where the generation density of pulse noise is high, by adapting the unit not to remove pulse noise of small level, it is made possible to reduce distortion of the FM demodulated signals to a minimum. Accordingly, it is made to reduce deterioration of the quality of FM voices to a minimum.

公开(公告)号：US20060013404A1

公开(公告)日：2006-01-19

申请号：US10524792

申请日：2003-08-21

Applicant: Tsuyoshi Koike ,  Hiroshi Miyagi

Inventor： Tsuyoshi Koike ,  Hiroshi Miyagi

IPC: H04H5/00

CPC classification number: H04H40/72 ,  H04B1/1676

Abstract: A stereo demodulator circuit comprising at least one noise control unit for performing a noise control responding to an RSSI (reception electric-field intensity) when the RSSI is within a specified range, further comprises an AD converter unit for AD-converting a signal corresponding to the RSSI and a control signal producing unit for producing a control signal for a noise control performed in the noise control unit according to a noise level when the noise level obtained by the AD conversion is within the above described specified range. The control signal producing unit comprises an offset unit for digitally offsetting a signal obtained through the above described AD conversion by a predefined value and truncating lower bits off the offset value by the number of bits in compliance with a grade of the noise control accuracy and outputs the control signal based on the signal obtained from the offset unit.

Abstract translation: 一种立体声解调器电路，包括至少一个噪声控制单元，用于当RSSI在指定范围内时响应于RSSI（接收电场强度）执行噪声控制，还包括AD转换单元，用于AD转换对应于 RSSI和控制信号产生单元，用于当通过AD转换获得的噪声电平在上述指定范围内时，根据噪声电平产生用于在噪声控制单元中执行的噪声控制的控制信号。 控制信号产生单元包括：偏移单元，用于通过预定义的值将通过上述AD转换获得的信号数字偏移，并根据噪声控制精度等级将偏移值的低位截断位数 基于从偏移单元获得的信号的控制信号。

公开(公告)号：US5661810A

公开(公告)日：1997-08-26

申请号：US522314

申请日：1995-08-25

Applicant: Djahanyar Chahabadi ,  Matthias Herrmann ,  Lothar Vogt ,  Jurgen Kaesser

Inventor： Djahanyar Chahabadi ,  Matthias Herrmann ,  Lothar Vogt ,  Jurgen Kaesser

IPC: H03H17/04 ,  H03H17/02 ,  H04B1/10 ,  H04B1/16 ,  H04B1/26 ,  H04B1/64 ,  H04H1/00 ,  H04H20/57 ,  H04H40/63 ,  H04H40/72 ,  H04H5/00

CPC classification number: H04H40/63 ,  H04H40/72 ,  H04H20/57

Abstract: The circuit arrangement includes a first low-pass filter (2) for filtering an input signal (H3) proportional to the strength of a received radio signal; a second low-pass filter (3) for filtering the input signal (H3); a first weighting circuit (7) for weighting the first low-pass filter output signal with first coefficients to form a first weighted output signal; a circuit device for forming a masking signal for reducing stereo channel isolation from the first weighted output signal; a second weighting circuit (5) for forming a second weighted output signal weighted with second coefficients from the first low-pass filter output signal or the second low-pass filter output signal according to a switching signal (DD2) indicative of interference in the audio signals; a switch device (4) for selecting the first low-pass filter output signal for weighting in the second weighting circuit means (5) when no interference is indicated by the switching signal (DD2) and the second low-pass filter output signal for weighting in the second weighting circuit means (5) when interference is indicated by the switching signal (DD2); and a circuit device for forming a masking signal for damping the audio signal from the second weighted output signal.

Abstract translation: PCT No.PCT / DE94 / 00321 Sec。 371日期1995年8月25日 102（e）日期1995年8月25日PCT 1994年3月22日PCT公布。 公开号WO94 / 22229 日期1995年9月29日该电路装置包括：第一低通滤波器（2），用于对与接收的无线电信号的强度成正比的输入信号（H3）进行滤波; 用于对输入信号（H3）进行滤波的第二低通滤波器（3）; 第一加权电路（7），用于利用第一系数对第一低通滤波器输出信号进行加权，以形成第一加权输出信号; 电路装置，用于形成用于减少立体声信道隔离的屏蔽信号与第一加权输出信号; 第二加权电路（5），用于根据指示音频中的干扰的切换信号（DD2），从第一低通滤波器输出信号或第二低通滤波器输出信号形成用第二系数加权的第二加权输出信号 信号; 开关装置（4），用于当没有由开关信号（DD2）指示干扰和用于加权的第二低通滤波器输出信号时，在第二加权电路装置（5）中选择用于加权的第一低通滤波器输出信号 在第二加权电路装置（5）中，当由切换信号（DD2）指示干扰时; 以及电路装置，用于形成用于阻尼来自第二加权输出信号的音频信号的屏蔽信号。