公开(公告)号：US5978420A

公开(公告)日：1999-11-02

申请号：US200084

申请日：1998-11-25

Applicant: Joshua L. Koslov ,  Frank A. Lane ,  Carl G. Scarpa

Inventor： Joshua L. Koslov ,  Frank A. Lane ,  Carl G. Scarpa

IPC: H03H17/00 ,  H04L27/20

CPC classification number: H04L27/2071

Abstract: In accordance with the present invention an interpolation technique is used to convert a low rate digital signal to a high rate signal and to shift the carrier to a desired frequency. This is accomplished, by first positioning the information signal, e.g., the digital waveform to be modulated on a carrier at a relatively low rate using a digital mixer operating at a fraction of the ultimate digital to analog conversion frequency. The relatively low rate signal generated by the mixing operation is then converted to a high rate signal by one or more interpolator stages. An adjustable passband filter circuit is included in each interpolation stage. One feature of the present invention is directed to a control circuit which is response to an H bit frequency control word representing a desired output carrier frequency. The control circuit generates individual filter control signals for each adjustable filter circuit from the single H bit frequency control word. An oscillator control circuit which is responsive to a portion of the H bit frequency control word is also described.

Abstract translation: 根据本发明，内插技术用于将低速率数字信号转换成高速率信号并将载波移位到期望的频率。 这是通过使用以最终数模转换频率的一小部分操作的数字混频器首先定位信息信号，例如以较低速率调制在载波上的数字波形。 然后由混合操作产生的相对较低的速率信号通过一个或多个内插器级转换成高速率信号。 每个插补级包含可调整通带滤波电路。 本发明的一个特征是针对表示期望输出载波频率的H位频率控制字的响应的控制电路。 控制电路从单个H位频率控制字为每个可调滤波器电路生成各个滤波器控制信号。 还描述了响应于H位频率控制字的一部分的振荡器控制电路。

公开(公告)号：US5282023A

公开(公告)日：1994-01-25

申请号：US882851

申请日：1992-05-14

Applicant: Carl G. Scarpa

Inventor： Carl G. Scarpa

IPC: H04N5/21 ,  H04N5/44 ,  H04N7/00 ,  H04N11/00

CPC classification number: H04N5/21

Abstract: An NTSC interference canceler for eliminating NTSC signal interference from a HDTV signal uses recursive notch filters with independently adjustable gains and center frequencies to isolate an NTSC signal's major components, i.e. the picture carrier signal, the chrominance subcarrier signal and the audio carrier signal. A single filter is used to isolate each NTSC interference signal component, with each particular filter's gain and center frequency being independently adjusted to match the amplitude and frequency of the particular NTSC interference signal component to be isolated by the filter. Once isolated, these interference signal components are substracted from the received television signal which includes both the NTSC interference signal and the HDTV signal. In this manner, the NTSC interference is removed from the HDTV signal.

Abstract translation: 用于消除HDTV信号的NTSC信号干扰的NTSC干扰消除器使用具有可独立调节的增益和中心频率的递归陷波滤波器来隔离NTSC信号的主要分量，即图像载波信号，色度副载波信号和音频载波信号。 使用单个滤波器来隔离每个NTSC干扰信号分量，每个特定的滤波器的增益和中心频率被独立地调整以匹配由滤波器隔离的特定NTSC干扰信号分量的幅度和频率。 一旦隔离，这些干扰信号分量从包括NTSC干扰信号和HDTV信号的所接收的电视信号中减去。 以这种方式，从HDTV信号中去除NTSC干扰。

公开(公告)号：US07173991B2

公开(公告)日：2007-02-06

申请号：US10172984

申请日：2002-06-17

Applicant: Carl G. Scarpa

Inventor： Carl G. Scarpa

IPC: H04B1/10 ,  H03D1/00 ,  H04L27/06

CPC classification number: H04L25/022

Abstract: Methods and apparatus for performing spectral filtering of channel estimates corresponding to a communications channel used to transmit a multi-tone signal are described. A channel estimate is examined to identify portions where significant multi-path interference is present. Real, as opposed to complex, low pass filters are used to perform spectral filtering on the channel estimate to produce a filtered channel estimate. Values corresponding to portions of the channel estimate determined to correspond to areas where significant multi-path interference is present are replaced with the original unfiltered channel estimate values to generate a selectively filtered channel estimate. By using unfiltered channel estimate values in areas of multi-path interference, the errors introduced in such areas by real filtering are avoided without the need to resort to complex filtering.

Abstract translation: 描述用于执行与用于发送多音调信号的通信信道相对应的信道估计的频谱滤波的方法和装置。 检查信道估计以识别存在显着的多径干扰的部分。 实际，与复杂的低通滤波器相反，使用信道估计进行频谱滤波以产生滤波的信道估计。 对应于被确定为对应于存在有效多径干扰的区域的信道估计的部分的值被原始未滤波的信道估计值替换以产生选择性滤波的信道估计。 通过在多路径干扰区域中使用未滤波的信道估计值，避免了通过实际滤波在这些区域中引入的误差，而不需要诉诸复杂滤波。

公开(公告)号：US5694419A

公开(公告)日：1997-12-02

申请号：US554697

申请日：1995-11-07

Applicant: Koslov Joshua Lawrence ,  Frank Anton Lane ,  Carl G. Scarpa

Inventor： Koslov Joshua Lawrence ,  Frank Anton Lane ,  Carl G. Scarpa

IPC: H04B1/68 ,  H04L27/00 ,  H04L27/02

CPC classification number: H04B1/68 ,  H04L27/0008 ,  H04L27/02

Abstract: A common transceiver circuit for use as either a modulator or demodulator and that is implemented through a shared resource approach. This approach is particularly, though not exclusively, suited for vestigial sideband (VSB) signals. Specifically, a VSB transceiver circuit (700), through strategically located multiplexing stages, physically re-uses a complex vestigial Nyquist filter (610), a complex mixer (620) and an equalizer (785) during demodulation and modulation. The VSB transceiver also selects a particular configuration of a common complex Hilbert transform circuit (720) for use during either demodulation or modulation. In addition, the same equalizer selectively provides both channel equalization, during de-modulation, and (sin x)/x compensation, during modulation, through use of differing corresponding sets of tap coefficients.

Abstract translation: 用作调制器或解调器的通用收发器电路，通过共享资源方法实现。 该方法特别地，尽管不是排他地适用于残留边带（VSB）信号。 具体地说，在解调和调制期间，通过策略地定位的多路复用级的VSB收发器电路（700）在物理上重新使用复杂的残余奈奎斯特滤波器（610），复合混频器（620）和均衡器（785）。 VSB收发器还选择在解调或调制期间使用的公共复合希尔伯特变换电路（720）的特定配置。 此外，相同的均衡器通过使用不同对应的抽头系数组，在调制期间，在去调制期间和（sin x）/ x补偿期间选择性地提供信道均衡。

公开(公告)号：US5563916A

公开(公告)日：1996-10-08

申请号：US461417

申请日：1995-06-05

Applicant: Carl G. Scarpa

Inventor： Carl G. Scarpa

IPC: H03G3/00 ,  H03G3/20 ,  H04L27/08

CPC classification number: H03G3/3052 ,  H03G3/001

Abstract: An apparatus and method for varying the slew rate of a digital AGC circuit is disclosed. A gain amplifier receiving an analog signal from a tuner is converted by an A/D converter into a digital form. An ABS circuit then obtains an absolute value level of the signal, which is then low pass filtered. The filtered signal is compared to a reference level to determine if the gain should be increased or decreased. The filtered signal is also communicated to a lock detect circuit to determine how far out of the desired range the signal is, thereby requiring large step changes for a fast, coarse adjustment or smaller step changes fine adjustment of the gain. An integrator combines the two results to determine the varying slew rate of the gain signal, which is converted back to the analog domain to control the amplifier.

Abstract translation: 公开了一种用于改变数字AGC电路的转换速率的装置和方法。 接收来自调谐器的模拟信号的增益放大器由A / D转换器转换为数字形式。 然后，ABS电路获得信号的绝对值电平，然后低通滤波。 将经滤波的信号与参考电平进行比较，以确定增益是否应当增加或减小。 滤波后的信号也传送到锁定检测电路，以确定信号在多远的范围内，从而需要较大的阶梯变化以进行快速，粗调或更小的步长改变增益的微调。 积分器组合了两个结果，以确定增益信号的变化转换速率，其被转换回模拟域以控制放大器。

公开(公告)号：US5325188A

公开(公告)日：1994-06-28

申请号：US3714

申请日：1993-01-13

Applicant: Carl G. Scarpa

Inventor： Carl G. Scarpa

IPC: H04N5/21 ,  H04N5/44 ,  H04N7/00 ,  H04N11/00

CPC classification number: H04N5/21

Abstract: An NTSC interference canceler for eliminating NTSC signal interference from a HDTV signal uses recursive notch filters with adjustable center frequencies to isolate an NTSC signal's major components, i.e. the picture carrier signal, the chrominance subcarrier signal and the audio carrier signal. A single filter is used to isolate each NTSC interference signal component, with each particular filter's center frequency being adjusted to match the frequency of the particular NTSC interference signal component to be isolated by the filter. Each filter's gain may be either fixed or dynamically adjusted to match the amplitude of the NTSC interference signal component. Once isolated, these interference signal components are subtracted from the received television signal which includes both the NTSC interference signal and the HDTV signal. In this manner, the NTSC interference is removed from the HDTV signal.

Abstract translation: 用于消除HDTV信号的NTSC信号干扰的NTSC干扰消除器使用具有可调中心频率的递归陷波滤波器来隔离NTSC信号的主要分量，即图像载波信号，色度副载波信号和音频载波信号。 使用单个滤波器来隔离每个NTSC干扰信号分量，每个特定滤波器的中心频率被调整以匹配由滤波器隔离的特定NTSC干扰信号分量的频率。 每个滤波器的增益可以是固定的或动态地调节以匹配NTSC干扰信号分量的幅度。 一旦被隔离，从包括NTSC干扰信号和HDTV信号的所接收的电视信号中减去这些干扰信号分量。 以这种方式，从HDTV信号中去除NTSC干扰。

公开(公告)号：US07139340B2

公开(公告)日：2006-11-21

申请号：US10185971

申请日：2002-06-28

Applicant: Carl G. Scarpa

Inventor： Carl G. Scarpa

IPC: H04L27/06

CPC classification number: H04L27/266 ,  H04L27/2659 ,  H04L27/2675 ,  H04L27/2679 ,  H04L2027/0028 ,  H04L2027/0075 ,  H04L2027/0095

Abstract: Methods and apparatus for estimating and correcting carrier frequency offsets in a bust multi-tone receiver are described. Course and fine carrier frequency estimates are generated from the signal's preamble. Decision directed carrier frequency offset estimates are then generated from the signal field and data fields of the multi-tone signal. Frequency error estimates are generated for each tone of the signal and combined using a weighted average to generate the frequency error estimate used to perform the correction operation. Error estimates corresponding to noisy data tones are weighted less then estimates corresponding to less noisy data tones. In cases of low SNR frequency error estimates corresponding to pilots are weighted by an extra amount as compared to error estimates corresponding to tones used to transmit data symbols. During times of high SNR error estimates corresponding to pilot tones are weighted in the same manner as error estimates corresponding to data tones.

Abstract translation: 描述了用于估计和校正胸围多音调接收机中的载波频率偏移的方法和装置。 从信号的前导码生成课程和精细载波频率估计。 然后根据多音调信号的信号场和数据场产生决策导向载波频率偏移估计。 针对信号的每个音调产生频率误差估计，并使用加权平均值组合以产生用于执行校正操作的频率误差估计。 与噪声数据音调相对应的误差估计被加权小于对应于较少嘈杂数据音调的估计。 在低SNR的情况下，与对应于用于发送数据符号的音调的误差估计值相比，对应于导频的估计值加权额外的量。 在高SNR的时间期间，对应于导频音调的误差估计以与对应于数据音调的误差估计相同的方式进行加权。

公开(公告)号：US6052701A

公开(公告)日：2000-04-18

申请号：US200083

申请日：1998-11-25

Applicant: Joshua L. Koslov ,  Frank A. Lane ,  Carl G. Scarpa

Inventor： Joshua L. Koslov ,  Frank A. Lane ,  Carl G. Scarpa

IPC: H03H17/00 ,  H04L27/20 ,  G06F7/17 ,  A04L27/20

CPC classification number: H04L27/2071

Abstract: Methods and apparatus for converting a relatively low frequency signal, e.g., a 1.5 MHz signal, to a high frequency signal, e.g., a 30-100 MHz signal, in the digital domain without the need for a digital mixer operating at the high frequency are described. The high frequency represents, e.g., the ultimate digital to analog conversion frequency. In accordance with the present invention an interpolation technique is used to convert the low rate digital signal to a high rate signal and to shift the carrier to a desired frequency. This is accomplished, by first positioning the information signal, e.g., the digital waveform to be modulated on a carrier at a relatively low rate using a digital mixer operating at a fraction of the ultimate digital to analog conversion frequency. The relatively low rate signal generated by the mixing operation is then converted to a high rate signal by one or more interpolator stages. An adjustable passband filter circuit is included in each interpolation stage. In one embodiment, the adjustable passband filter circuits are implemented using a fixed frequency filter preceded and followed by frequency shifting circuits which are used to upshift and then downshift the signal being filtered. By controlling the frequency shifting adjustable filter circuits are achieved via the use of fixed filters.

Abstract translation: 用于将相对低频信号（例如1.5MHz信号）转换成数字域中的高频信号（例如，30-100MHz信号）而不需要以高频工作的数字混频器的方法和装置 描述。 高频表示例如最终的数模转换频率。 根据本发明，使用内插技术将低速率数字信号转换为高速率信号并将载波移位到期望的频率。 这是通过使用以最终数模转换频率的一小部分操作的数字混频器首先定位信息信号，例如以较低速率调制在载波上的数字波形。 然后由混合操作产生的相对较低的速率信号通过一个或多个内插器级转换成高速率信号。 每个插补级包含可调整通带滤波电路。 在一个实施例中，可调节通带滤波器电路使用在频移电路之前和之后的固定频率滤波器来实现，所述频移电路用于升档，然后降档正被滤波的信号。 通过控制频移可调滤波器电路是通过使用固定滤波器实现的。

公开(公告)号：US5692013A

公开(公告)日：1997-11-25

申请号：US554696

申请日：1995-11-07

Applicant: Joshua Lawrence Koslov ,  Frank Anton Lane ,  Carl G. Scarpa

Inventor： Joshua Lawrence Koslov ,  Frank Anton Lane ,  Carl G. Scarpa

IPC: H04L27/36 ,  H04L27/38 ,  H04L27/10

CPC classification number: H04L27/3854 ,  H04L27/362

Abstract: A common transceiver circuit for use as either a modulator or demodulator and that is implemented through a shared resource approach. This approach is particularly, though not exclusively, suited for with quadrature amplitude modulated (QAM) or vestigial sideband (VSB) signals. Specifically, a QAM transceiver circuit (400), through strategically located multiplexing stages, physically re-uses both a complex Nyquist filter (310, 320) and an equalizer (140) for demodulation and modulation. Additionally, tap coefficients of the complex Nyquist filter are set such that a center frequency of an otherwise baseband Nyquist filter is translated upward to a symbol rate in order to eliminate a separate complex mixer (250, 260). Similarly, a VSB transceiver circuit (700), also through strategically located multiplexing stages, physically re-uses a complex vestigial Nyquist filter (610), a complex mixer (620) and an equalizer (785) during demodulation and modulation. The VSB transceiver also selects a particular configuration of a common complex Hilbert transform circuit (720) for use during either demodulation or modulation. In either transceiver, the same equalizer selectively provides both channel equalization, during de-modulation, and (sin x)/x compensation, during modulation, through use of differing corresponding sets of tap coefficients.

Abstract translation: 用作调制器或解调器的通用收发器电路，通过共享资源方法实现。 该方法特别地，尽管不是排他地适用于正交幅度调制（QAM）或残留边带（VSB）信号。 具体地说，QAM收发器电路（400）通过策略地定位的复用级，物理地重新使用复数奈奎斯特滤波器（310,320）和均衡器（140）进行解调和调制。 此外，复数奈奎斯特滤波器的抽头系数被设置为使得否则基带奈奎斯特滤波器的中心频率向上转换到符号速率，以消除单独的复合混频器（250,260）。 类似地，在解调和调制期间，也通过策略地定位的复用级的VSB收发器电路（700）在物理上重新使用复杂的残留奈奎斯特滤波器（610），复混合器（620）和均衡器（785）。 VSB收发器还选择在解调或调制期间使用的公共复合希尔伯特变换电路（720）的特定配置。 在任一收发器中，相同的均衡器通过使用不同对应的抽头系数组，在调制期间，在去调制期间和（sin x）/ x补偿期间选择性地提供信道均衡。

公开(公告)号：US5978823A

公开(公告)日：1999-11-02

申请号：US789437

申请日：1997-01-27

Applicant: Joshua L. Koslov ,  Frank A. Lane ,  Carl G. Scarpa

Inventor： Joshua L. Koslov ,  Frank A. Lane ,  Carl G. Scarpa

IPC: H03H17/00 ,  H04L27/20 ,  G06F17/17

CPC classification number: H04L27/2071

Abstract: Methods and apparatus for converting a relatively low frequency signal, e.g., a 1.5 MHz signal, to a high frequency signal, e.g., a 30-100 MHz signal, in the digital domain without the need for a digital mixer operating at the high frequency are described. The high frequency represents, e.g., the ultimate digital to analog conversion frequency. In accordance with the present invention an interpolation technique is used to convert the low rate digital signal to a high rate signal and to shift the carrier to a desired frequency. This is accomplished, by first positioning the information signal, e.g., the digital waveform to be modulated on a carrier at a relatively low rate using a digital mixer operating at a fraction of the ultimate digital to analog conversion frequency. The relatively low rate signal generated by the mixing operation is then converted to a high rate signal by one or more interpolator stages. An adjustable passband filter circuit is included in each interpolation stage. In one embodiment, the adjustable passband filter circuits are implemented using a fixed frequency filter preceded and followed by frequency shifting circuits which are used to upshift and then downshift the signal being filtered. By controlling the frequency shifting adjustable filter circuits are achieved via the use of fixed filters. One feature of the present invention is directed to a control circuit which is response to an H bit frequency control word representing a desired output carrier frequency.

Abstract translation: 用于将相对低频信号（例如1.5MHz信号）转换成数字域中的高频信号（例如，30-100MHz信号）而不需要以高频工作的数字混频器的方法和装置 描述。 高频表示例如最终的数模转换频率。 根据本发明，使用内插技术将低速率数字信号转换为高速率信号并将载波移位到期望的频率。 这是通过使用以最终数模转换频率的一小部分操作的数字混频器首先定位信息信号，例如以较低速率调制在载波上的数字波形。 然后由混合操作产生的相对较低的速率信号通过一个或多个内插器级转换成高速率信号。 每个插补级包含可调整通带滤波电路。 在一个实施例中，可调节通带滤波器电路使用在频移电路之前和之后的固定频率滤波器来实现，所述频移电路用于升档，然后降档正被滤波的信号。 通过控制频移可调滤波器电路是通过使用固定滤波器实现的。 本发明的一个特征是针对表示期望输出载波频率的H位频率控制字的响应的控制电路。