公开(公告)号：US06982948B2

公开(公告)日：2006-01-03

申请号：US10342764

申请日：2003-01-15

Applicant: Brian William Kroeger ,  Jeffrey S. Baird

Inventor： Brian William Kroeger ,  Jeffrey S. Baird

IPC: H04J11/00

CPC classification number: H04L27/2613 ,  H04H20/30 ,  H04H2201/183 ,  H04H2201/20 ,  H04L1/004 ,  H04L5/0048 ,  H04L25/0226 ,  H04L25/0228 ,  H04L25/03159 ,  H04L27/2071 ,  H04L27/2655

Abstract: A transmitter for transmitting data in a digital audio broadcasting system includes a signal generator for providing a plurality of orthogonal frequency division multiplexed sub-carriers, with the sub-carriers including data sub-carriers and reference sub-carriers, and a modulator for modulating the data sub-carriers with a digital signal representative of information to be transmitted. The reference sub-carriers are modulated with a sequence of timing bits, wherein the sequence of timing bits includes an unambiguous block synchronization word, and the number of bits comprising the block synchronization word is less than one half of the number of bits in said timing sequence. The orthogonal frequency division multiplexed sub-carriers are transmitted to receivers that differentially detect the block synchronization word and use the block synchronization word to coherently detect the digital signal representative of information to be transmitted are also included.

公开(公告)号：US06901242B2

公开(公告)日：2005-05-31

申请号：US09747143

申请日：2000-12-22

Applicant: Brian W. Kroeger ,  Roy R. Stehlik

Inventor： Brian W. Kroeger ,  Roy R. Stehlik

IPC: H04L27/00 ,  H04B1/16 ,  H04B7/12 ,  H04H20/46 ,  H04L1/02 ,  H04L1/04 ,  H04L27/26 ,  H04L27/32 ,  H04B1/00 ,  H04B1/10 ,  H04B7/00 ,  H04B15/00 ,  H04B17/00

CPC classification number: H04H20/22 ,  H04B7/12 ,  H04H20/30 ,  H04H60/11 ,  H04H2201/183 ,  H04H2201/20 ,  H04L1/02 ,  H04L5/0005

Abstract: A system is provided wherein a primary radio signal and a redundant radio signal are transmitted from a transmitter subsystem and received by a receiver subsystem. The output of an audio source is coupled to a modulator for modulating a radio frequency signal for coupling to a transmit antenna. A second output of audio source is coupled to a delay circuit, for adding a predetermined time delay thereto. The delayed audio source signal is coupled to a modulator for modulating a second radio frequency signal that is also coupled to the transmit antenna. The receiver subsystem receives both the primary radio signal and the delayed redundant radio signal and couples each to a respective demodulator. At least one demodulator includes a circuit for determining the degradation in the primary radio signal and provides a quality measurement output signal to a blend control circuit.

Abstract translation: 提供了一种系统，其中主要无线电信号和冗余无线电信号从发射机子系统发射并由接收机子系统接收。 音频源的输出耦合到调制器，用于调制用于耦合到发射天线的射频信号。 音频源的第二输出耦合到延迟电路，用于向其添加预定的时间延迟。 延迟的音频源信号耦合到调制器，用于调制也耦合到发射天线的第二射频信号。 接收机子系统接收主无线电信号和延迟的冗余无线电信号，并将每个信号耦合到相应的解调器。 至少一个解调器包括用于确定主无线电信号的劣化的电路，并向混合控制电路提供质量测量输出信号。

公开(公告)号：US20040235440A1

公开(公告)日：2004-11-25

申请号：US10441132

申请日：2003-05-19

Inventor： Todd A. Toporski ,  J. William Whikehart

IPC: H04B001/18

CPC classification number: H04H60/44 ,  H03J1/0075 ,  H04H20/30 ,  H04H2201/13 ,  H04H2201/183

Abstract: A radio receiver performs a fast tune to a target frequency channel potentially containing a hybrid broadcast signal for determining whether analog signal contained in the hybrid broadcast signal contains an identifying data indicating the presence of a digital broadcast station before attempting to decode a digital signal contained in the hybrid broadcast signal.

Abstract translation: 无线电接收机对可能包含混合广播信号的目标频道进行快速调谐，以确定在混合广播信号中包含的模拟信号是否包含指示数字广播电台的存在的识别数据，然后再尝试解码包含在 混合广播信号。

公开(公告)号：US06622008B2

公开(公告)日：2003-09-16

申请号：US09860246

申请日：2001-05-18

Applicant: Brian William Kroeger ,  Jeffrey Scott Baird

Inventor： Brian William Kroeger ,  Jeffrey Scott Baird

IPC: H04B100

CPC classification number: H04B1/109 ,  H04H40/27 ,  H04H2201/183 ,  H04L25/03006

Abstract: This invention provides a method for reducing FM interference in an in-band on-channel digital audio broadcasting system. The method includes the steps of receiving a composite signal including a signal of interest and an interfering signal and normalizing the composite signal to produce a normalized composite signal. The composite signal is then multiplied by the complex conjugate of the normalized composite signal to produce a real signal. Then the real signal is filtered and the resulting filtered signal is multiplied by the normalized composite signal to produce an output signal. The adverse effects of the interfering signal in the output signal are reduced with respect to the magnitude of the signal of interest reducing FM interference in an in-band on-channel digital audio broadcasting system, thereby making it easier to detect the signal of interest. The output signal and the composite can be blended in response to the power of the real and filtered signals Radio receivers that utilize the above method are also included.

Abstract translation: 本发明提供一种降低带内同频数字音频广播系统中的FM干扰的方法。 该方法包括以下步骤：接收包括感兴趣的信号和干扰信号的复合信号，并对复合信号进行归一化以产生归一化复合信号。 然后将复合信号乘以归一化复合信号的复共轭以产生实信号。 然后对实信号进行滤波，并将得到的滤波信号乘以归一化复合信号以产生输出信号。 输出信号中的干扰信号的不利影响相对于感兴趣的信号的幅度减小，从而降低带内同频数字音频广播系统中的FM干扰，从而使得更容易检测感兴趣的信号。 响应于实际和滤波信号的功率，输出信号和复合可以混合使用上述方法的无线电接收机也包括在内。

公开(公告)号：US06622007B2

公开(公告)日：2003-09-16

申请号：US09777503

申请日：2001-02-05

Applicant: Thomas M. Linden

Inventor： Thomas M. Linden

IPC: H04Q720

CPC classification number: H04H20/30 ,  H04H20/42 ,  H04H60/06 ,  H04H2201/183 ,  H04N21/2402 ,  H04N21/26216 ,  H04N21/2665 ,  H04N21/6112 ,  H04N21/8106 ,  H04N21/8126

Abstract: A network datacast system includes a plurality of transmission facilities. Each transmission facility receives primary programs from one or more media studios. Each transmission facility also receives ancillary data programs from a network datacast center. Each transmission facility broadcasts a wireless signal that includes a primary channel and at least one ancillary data channel. The transmission facilities contemporaneously transmit the ancillary programs on the ancillary data channels. A network datacast receiver contemporaneously receives the wireless signals and extracts the datacast programs from each datacast signal. The extracted datacast programs are stored in the receiver for subsequent output to the user.

公开(公告)号：US06549544B1

公开(公告)日：2003-04-15

申请号：US09438148

申请日：1999-11-10

Applicant: Brian William Kroeger ,  Jeffrey S. Baird

Inventor： Brian William Kroeger ,  Jeffrey S. Baird

IPC: H04J100

CPC classification number: H04L27/2613 ,  H04H20/30 ,  H04H2201/183 ,  H04H2201/20 ,  H04L1/004 ,  H04L5/0048 ,  H04L25/0226 ,  H04L25/0228 ,  H04L25/03159 ,  H04L27/2071 ,  H04L27/2655

Abstract: A method for transmission of data in a digital audio broadcasting system includes the steps of providing a plurality of orthogonal frequency division multiplexed sub-carriers, with the sub-carriers including data sub-carriers and reference sub-carriers, and modulating the data sub-carriers with a digital signal representative of information to be transmitted. The reference sub-carriers are modulated with a sequence of timing bits, wherein the sequence of timing bits includes an unambiguous block synchronization word, and the number of bits comprising the block synchronization word is less than one half of the number of bits in said timing sequence. Then the orthogonal frequency division multiplexed sub-carriers are transmitted. Receivers that differentially detect the block synchronization word and use the block synchronization word to coherently detect the digital signal representative of information to be transmitted are also included.

Abstract translation: 一种在数字音频广播系统中传输数据的方法包括以下步骤：提供多个正交频分多路复用子载波，子载波包括数据子载波和参考副载波， 具有表示要发送的信息的数字信号的载波。 参考子载波用定时位序列调制，其中定时位序列包括明确的块同步字，并且包括块同步字的比特数小于所述定时中的比特数的一半 序列。 然后发送正交频分复用子载波。 还包括差分检测块同步字并使用块同步字相干检测表示要发送的信息的数字信号的接收器。

公开(公告)号：US06445693B1

公开(公告)日：2002-09-03

申请号：US09396011

申请日：1999-09-15

Applicant: Mohsen Sarraf ,  Mohammad Hossein Zarrabizadeh

Inventor： Mohsen Sarraf ,  Mohammad Hossein Zarrabizadeh

IPC: H04J100

CPC classification number: H04H20/12 ,  H04B1/1027 ,  H04H2201/183 ,  H04H2201/20 ,  H04L5/023 ,  H04L27/2608 ,  H04W52/16

Abstract: A method and apparatus are disclosed for estimating the power of the first adjacent FM interference and for using the estimated power to identify the number of OFDM bins that are at least partially corrupted by the first adjacent FM interference. The number of corrupted bins, Ncorr, is obtained based on measurements of the power of each of the first adjacent FM analog interference, Ik, and the power of the background noise, Nk, of the digital side bands. The power measurements, together with the known slope of the first adjacent FM analog interference, is used to identify when the power of the measured background level equals the prorated power of the slope. All of the bins that fall below a threshold value are determined to be at least partially corrupted. The FFT output provides the power of the first adjacent FM analog interference, Ik, measured, for example, at ±200 kHz, and the power of the background noise, Nk, of each of the digital side bands, measured, for example, at 130 kHz and −130 kHz. In a hard-masking implementation, the corrupted bins are discarded (set to zero) and in a soft-masking implementation, the partially corrupted bins are scaled according to the interference slope before further processing, for example, by the Viterbi decoder.

Abstract translation: 公开了一种用于估计第一相邻FM干扰的功率并且使用估计的功率来识别由第一相邻FM干扰至少部分地被破坏的OFDM信元的数量的方法和装置。 基于第一相邻FM模拟干扰I k的功率和数字侧频带的背景噪声的功率N k的功率的测量，获得损坏的箱的数量Ncorr。 功率测量结果与第一相邻FM模拟干扰的已知斜率一起用于识别测量背景等级的功率何时等于斜率的分配功率。 低于阈值的所有箱被确定为至少部分损坏。 FFT输出提供第一相邻FM模拟干扰Ik的功率，I k，例如在±200kHz下测量，并且每个数字边带的背景噪声Nk的功率例如在 130 kHz和-130 kHz。 在硬掩蔽实现中，损坏的箱被丢弃（设置为零），并且在软掩蔽实现中，部分损坏的箱根据例如维特比解码器进一步处理之前的干扰斜率进行缩放。

公开(公告)号：US20010003089A1

公开(公告)日：2001-06-07

申请号：US09747143

申请日：2000-12-22

Inventor： Brian W. Kroeger ,  Roy R. Stehlik

IPC: H04B001/00

CPC classification number: H04H20/22 ,  H04B7/12 ,  H04H20/30 ,  H04H60/11 ,  H04H2201/183 ,  H04H2201/20 ,  H04L1/02 ,  H04L5/0005

Abstract: A system (100) for mitigating intermittent interruptions in an audio radio broadcast system is provided wherein a primary radio signal and a redundant radio signal are transmitted from a transmitter subsystem (120) and received by a receiver subsystem (140). The output (112) of an audio source (110) is coupled to a modulator (160) for modulating a radio frequency signal (162) for coupling to a transmit antenna (172). A second output (114) of audio source (110) is coupled to a delay circuit (116), for adding a predetermined time delay thereto. The delayed audio source signal is coupled to modulator (164) for modulating a second radio frequency signal (166) that is also coupled to the transmit antenna (172). The receiver subsystem (140) receives both the primary radio signal and the delayed redundant radio signal and couples each to a respective demodulator (180, 182). At least demodulator (180) includes a circuit (181) for determining the degradation in the primary radio signal and provides a quality measurement output signal (186) to a blend control circuit (190). The recovered primary audio signal from demodulator (180) is coupled to a second delay circuit (184), the time delay of second delay circuit (184) being substantially equal to the time delay of delay circuit (116). The audio output from delay circuit (184) and the redundant audio output from demodulator (182) are coupled to a blending subsystem (135), wherein each is combined with a weighting factor and then combined together to form a composite audio signal for coupling to the audio output circuit (150).

Abstract translation: 提供一种用于减轻音频无线电广播系统中的间歇性中断的系统（100），其中主要无线电信号和冗余无线电信号从发射机子系统（120）发送并由接收机子系统（140）接收。 音频源（110）的输出（112）耦合到调制器（160），用于调制用于耦合到发射天线（172）的射频信号（162）。 音频源（110）的第二输出（114）耦合到延迟电路（116），用于向其添加预定的时间延迟。 延迟的音频源信号耦合到调制器（164），用于调制也耦合到发射天线（172）的第二射频信号（166）。 接收机子系统（140）接收主无线电信号和延迟的冗余无线电信号，并且将每个信号耦合到相应的解调器（180,182）。 至少解调器（180）包括用于确定主无线电信号的劣化的电路（181），并向混合控制电路（190）提供质量测量输出信号（186）。 来自解调器（180）的恢复的主音频信号被耦合到第二延迟电路（184），第二延迟电路（184）的时间延迟基本上等于延迟电路（116）的时间延迟。 来自延迟电路（184）的音频输出和从解调器（182）输出的冗余音频耦合到混合子系统（135），其中每个与混合子系统（135）组合，然后组合在一起以形成复合音频信号，以耦合到 音频输出电路（150）。

公开(公告)号：US6144705A

公开(公告)日：2000-11-07

申请号：US704470

申请日：1996-08-22

Applicant: Haralabos C. Papadopoulos ,  Carl-Erik Wilhelm Sundberg

Inventor： Haralabos C. Papadopoulos ,  Carl-Erik Wilhelm Sundberg

IPC: H04J1/00 ,  H04H20/30 ,  H04J11/00 ,  H04L25/49

CPC classification number: H04H20/30 ,  H04H2201/183

Abstract: In a system for simulcasting digitally modulated and analog FM signals over the same FM frequency band, the effect of the analog FM signal on the digitally modulated signal in the simulcast is calculated and canceled from the latter signal before its transmission. As a result, the digital transmission is free from interference from the analog FM signal. Moreover, the digital transmission is designed in such a manner that the interference caused thereby to the analog FM signal is kept at a minimal level.

Abstract translation: 在同频FM频段中同步数字调制和模拟FM信号的系统中，模拟FM信号对联播中的数字调制信号的影响在传输之前被计算并从后一个信号中消除。 因此，数字传输不受模拟FM信号的干扰。 此外，数字传输被设计成使得由此模拟FM信号引起的干扰保持在最小的水平。

公开(公告)号：US6014407A

公开(公告)日：2000-01-11

申请号：US914456

申请日：1997-08-19

Applicant: Bill J. Hunsinger ,  Derek D. Kumar

Inventor： Bill J. Hunsinger ,  Derek D. Kumar

IPC: H04B1/40 ,  H04B1/707 ,  H04B1/7097 ,  H04H20/33 ,  H04J9/00 ,  H04J11/00 ,  H04J13/00 ,  H04J13/02 ,  H04L5/02 ,  H04L27/26 ,  H04K1/00

CPC classification number: H04L27/2601 ,  H04B1/406 ,  H04B1/707 ,  H04B1/7097 ,  H04H20/33 ,  H04J9/00 ,  H04L5/023 ,  H04H20/22 ,  H04H2201/183

Abstract: A system and method for transmitting digital information through a medium such as atmospheric free-space includes a transmitter which generates a signal based on a basis set of mutually orthogonal, spectrally-shaped, sequences of substantially equal length and having predetermined autocorrelation values. The sequences may resemble noise in at least some of their characteristics. The orthogonality or cross-correlation characteristics, the autocorrelation characteristics and the resemblance to noise are due to features derived from sequences of pseudo-random numbers which themselves resemble noise in at least some of their characteristics. The waveform set based on the sequences is modulated digitally. The modulated set may be summed together along with a wideband reference signal of reduced amplitude and optionally an FM analog signal to form a composite signal which is broadcast typically through free space to at least one receiver. The receiver separates the analog FM signal from the digital signal and thereafter demodulates the digital data-carrying waveforms and outputs a stream of digital data. It has been determined to be resistant to multipath degradation.