| Patent Number |
Title Of Patent |
Date Issued |
| 7551675 |
Method and apparatus for synchronized transmission and reception of data in a digital audio broa |
June 23, 2009 |
| A method of transmitting digital audio broadcasting signals comprises the steps of generating a plurality of output frames of information to be transmitted, wherein each of the output frames includes a plurality of blocks of data and each of the output frames is synchronized with an |
| 7546088 |
Method and apparatus for blending an audio signal in an in-band on-channel radio system |
June 9, 2009 |
| A method for processing a composite digital audio broadcast signal to mitigate intermittent interruptions in the reception of the digital audio broadcast signal, the method comprising the steps of separating an analog audio portion of the digital audio broadcast signal from a digital aud |
| 7542517 |
Peak-to-average power reduction for FM OFDM transmission |
June 2, 2009 |
| A method of reducing peak-to-average power ratio in an OFDM signal comprises the steps of modulating a set of subcarriers with a set of data symbol vectors to produce a first modulated signal, limiting the magnitude of the first modulated signal to produce a first limited modulated s |
| 7512175 |
Method for synchronizing exporter and exciter clocks |
March 31, 2009 |
| A method for synchronizing an exciter clock with a modem frame clock in a broadcasting system comprises the steps of receiving a plurality of modem frame pulses that are representative of the start of modem frames of audio signals and data signals, wherein timing of the modem frame pulse |
| 7474707 |
Bandwidth reduction of an FM broadcast signal using a baseband precompensation technique |
January 6, 2009 |
| A method of processing a baseband multiplex signal comprises the steps of frequency modulating the baseband multiplex signal to produce a first modulated signal, filtering the first modulated signal to produce a first filtered signal, demodulating the filtered signal to produce a dem |
| 7464324 |
Method and apparatus for forward error correction coding for an AM in-band on-channel digital au |
December 9, 2008 |
| A method of digital audio broadcasting comprises the steps of providing a plurality of bits of digital information to be transmitted, forward error correcting the bits of digital information using a combination of pragmatic trellis code modulation and complementary punctured code, and |
| 7352817 |
Method and apparatus for interleaving signal bits in a digital audio broadcasting system |
April 1, 2008 |
| This invention provides a method for interleaving bits of a digital signal representative of data and/or audio in a digital audio broadcasting system, the method comprising the step of: writing a plurality of bits of the digital signal to a matrix; and reading the bits from the matrix, |
| 7340010 |
Forward error correction coding for hybrid AM in-band on-channel digital audio broadcasting syst |
March 4, 2008 |
| An AM compatible digital audio broadcasting signal comprises an analog modulated carrier signal centrally positioned in a radio channel, wherein the analog modulated carrier signal is modulated by an analog signal, and a plurality of digitally modulated subcarrier signals in the radio |
| 7305056 |
Coherent tracking for FM in-band on-channel receivers |
December 4, 2007 |
| A method for coherently tracking a radio signal including at least one digitally modulated reference carrier is provided, wherein the method comprises the steps of demodulating the reference carrier to produce complex coherent reference gains, detecting a transient that affects the c |
| 7305043 |
Method and apparatus for formatting signals for digital audio broadcasting transmission and rece |
December 4, 2007 |
| A method for digital audio broadcasting comprising the steps of receiving a plurality of data bits to be transmitted, formatting the plurality of data bits into a plurality of protocol data units, inserting header bits at spaced locations within the protocol data units, and using the |
| 7221917 |
Adjacent channel interference mitigation for FM digital audio broadcasting receivers |
May 22, 2007 |
| A method of receiving an FM digital audio broadcasting signal including a first plurality of subcarriers in an upper sideband of a radio channel and a second plurality of subcarriers in a lower sideband of the radio channel comprises the steps of mixing the digital audio broadcasting |
| 7221688 |
Method and apparatus for receiving a digital audio broadcasting signal |
May 22, 2007 |
| A method for processing a composite digital audio broadcasting signal including an analog modulated portion in a central frequency band and digitally modulated portions in upper and lower sidebands with respect to the central frequency band, the method comprises the steps of wideband |
| 7191136 |
Efficient coding of high frequency signal information in a signal using a linear/non-linear pred |
March 13, 2007 |
| An efficient coding scheme with higher audio bandwidth and/or better audio quality at lower bitrates, wherein the scheme eliminates long-term and short-term frequency domain correlation in a signal via frequency domain predictors. The coding scheme compresses information consisting of co |
| 7127008 |
Coherent AM demodulator using a weighted LSB/USB sum for interference mitigation |
October 24, 2006 |
| A method of processing an AM radio signal comprises the step of receiving an AM radio signal including an upper sideband portion and a lower sideband portion, demodulating the upper sideband portion and the lower sideband portion to produce a demodulated upper sideband signal and a d |
| 7043681 |
Digital audio broadcasting method and apparatus using complementary pattern-mapped convolutional |
May 9, 2006 |
| A method of transmitting digital information comprises the steps of forward error correction encoding a plurality of bits of digital information using complementary pattern-mapped convolutional codes, modulating a plurality of carrier signals with the forward error corrected bits, an |
| 6982948 |
Method and apparatus for transmission and reception of FM in-band on-channel digital audio broad |
January 3, 2006 |
| 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 fo |
| 6970685 |
Method and apparatus for dynamic filter selection in radio receivers |
November 29, 2005 |
| A method for processing a radio signal which may include a narrowband signal or a wideband signal or both, comprises the steps of receiving the radio signal, initially processing the radio signal using a narrowband filter, switching to a wideband filter for further processing of the radi |
| 6901242 |
System and method for mitigating intermittent interruptions in an audio radio broadcast system |
May 31, 2005 |
| 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 transm |
| 6898249 |
Method and apparatus for AM digital audio broadcasting with amplitude scaled tertiary subcarrier |
May 24, 2005 |
| A method of in-band on-channel (IBOC) digital audio broadcasting (DAB) comprises the steps of providing an analog modulated carrier signal in a central frequency band of an AM radio channel, providing a first plurality of subcarriers in an upper sideband of the AM radio channel, providin |
| 6895060 |
Adaptive weighting method for orthogonal frequency division multiplexed soft symbols using chann |
May 17, 2005 |
| A method for weighting orthogonal frequency division multiplexed soft symbols is provided, including the steps of receiving a plurality of sub-carriers modulated by digital information and filtering the sub-carriers to produce complex soft decision outputs. The magnitudes of the soft |
| 6891898 |
System and method for recovering symbol timing offset and carrier frequency error in an OFDM dig |
May 10, 2005 |
| The system for recovering symbol timing offset and carrier frequency error from an orthogonal frequency division multiplexed (OFDM) signal includes a receiver circuit for receiving an OFDM modulated signal representing a series of OFDM symbols, and providing a received signal to an outpu |
| 6845230 |
System and method for a push-pull gateway-directed digital receiver |
January 18, 2005 |
| A receiver is described for receiving digital data broadcasts from a Push-Pull gateway. The receiver is equipped with a demodulator, deinterleaver and turbo broadcast decoder for parsing and rendering the received broadcast data. Additionally, the receiver is also equipped with a GPS |
| 6798849 |
AM digital audio broadcasting with analog signal pre-compensation |
September 28, 2004 |
| A method for pre-compensating an analog signal in a composite digital audio broadcasting signal including the analog signal and a plurality of digitally modulated sub-carrier signals, the method comprising the steps of sampling the analog signal to obtain successive blocks of samples, |
| 6735257 |
Audio blend method and apparatus for AM and FM in-band on-channel digital audio broadcasting |
May 11, 2004 |
| A method is provided for transmitting a composite digital audio broadcast signal having an analog portion and a digital portion to mitigate intermittent interruptions in the reception of said digital audio broadcast signal. The method comprises the steps of arranging symbols represen |
| 6721337 |
Method and apparatus for transmission and reception of compressed audio frames with prioritized |
April 13, 2004 |
| A method for transmission of compressed data for a digital audio broadcasting system comprises the steps of producing digital information representative of an audio signal; estimating the number of bits to be allocated to the digital information in a modem frame; encoding the digital |
| 6671340 |
Method and apparatus for reduction of interference in FM in-band on-channel digital audio broadc |
December 30, 2003 |
| This invention provides a method for reducing radio frequency interference in an FM in-band on-channel digital audio broadcasting receiver. The method comprises the steps of receiving a composite signal including a signal of interest and an interfering signal, demodulating the composite |
| 6639949 |
Method and apparatus for pulse overlap pre-compensation in digitally modulated signals |
October 28, 2003 |
| A method of pre-compensating for pulse overlap in a digitally modulated signal comprises the steps of receiving a sequence of pulses, modulating the pulses to produce a first sequence of modulated pulses, demodulating the first sequence of modulated pulses to produce a first sequence of |
| 6622008 |
Method and apparatus for reduction of FM interference for FM in-band on-channel digital audio br |
September 16, 2003 |
| 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 |
| 6590944 |
Audio blend method and apparatus for AM and FM in band on channel digital audio broadcasting |
July 8, 2003 |
| A method is provided for processing a composite digital audio broadcast signal to mitigate intermittent interruptions in the reception of said digital audio broadcast signal. The method includes the steps of separating an analog modulated portion of the digital audio broadcast signal |
| 6570943 |
Method for equalization of complementary carriers in an AM compatible digital audio broadcast sy |
May 27, 2003 |
| A method is provided for equalizing an amplitude modulated compatible digital broadcasting signal which includes an amplitude modulated radio frequency signal having a first frequency spectrum, the amplitude modulated radio frequency signal having a first carrier modulated by an anal |
| 6563880 |
Method and system for simultaneously broadcasting and receiving digital and analog signals |
May 13, 2003 |
| 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 au |
| 6556639 |
Method and apparatus for determining transmission mode and synchronization for a digital audio b |
April 29, 2003 |
| A method is provided for transmitting control information in a digital audio broadcasting system. The method comprises the steps of transmitting a plurality of control bits in each of a plurality of control frames, wherein a first sequence of the control bits represents a transmission |
| 6549544 |
Method and apparatus for transmission and reception of FM in-band on-channel digital audio broad |
April 15, 2003 |
| 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-ca |
| 6539063 |
System and method for recovering symbol timing offset and carrier frequency error in an OFDM dig |
March 25, 2003 |
| The system for recovering symbol timing offset and carrier frequency error from an orthogonal frequency division multiplexed (OFDM) signal includes a receiver circuit for receiving an OFDM modulated signal representing a series of OFDM symbols, and providing a received signal to an outpu |
| 6532258 |
Method for estimating signal-to-noise ratio of digital carriers in an AM compatible digital audi |
March 11, 2003 |
| A method of estimating SNR for a plurality of carriers modulated with digital information, wherein the digital information includes data baud and training baud, comprising the steps of: receiving the plurality of carriers; determining a first SNR for the data baud; determining a second |
| 6523147 |
Method and apparatus for forward error correction coding for an AM in-band on-channel digital au |
February 18, 2003 |
| A method for digital audio broadcasting comprises the steps of providing a plurality of bits of digital information to be transmitted, interleaving the bits of digital information into a plurality of partitions, forward error correcting the bits of digital information using a combination |
| 6510175 |
In-band on-channel digital broadcasting |
January 21, 2003 |
| A system for combining AM and FM transmissions. In-band, on-channel, FM Digital Audio Broadcast (IBOC FM-DAB) allows simultaneous transmission of DAB and FM over existing FM allocations without interfering with conventional analog FM signals. The utility of existing FM spectrum alloc |
| 6487256 |
Method and apparatus for AM digital broadcasting |
November 26, 2002 |
| A method for AM in-band-on-channel (IBOC) digital audio broadcasting (DAB) uses a center channel signal in a central frequency band of an AM radio channel, the center channel signal is modulated by first and second versions of the program material to be transmitted. Sub-carriers in a |
| 6480536 |
Method and apparatus for demodulating and equalizing an AM compatible digital audio broadcast si |
November 12, 2002 |
| A method of demodulation and equalization is used to process an amplitude modulated compatible digital broadcasting signal including an amplitude modulated radio frequency signal having a first carrier modulated by an analog program signal in a first frequency spectrum, a plurality of |
| 6452977 |
Method and apparatus for AM compatible digital broadcasting |
September 17, 2002 |
| A broadcasting method for simultaneously broadcasting analog and digital signals in a standard AM broadcasting channel is provided by: broadcasting an amplitude modulated radio frequency signal having a first frequency spectrum, wherein the amplitude modulated radio frequency signal incl |
| 6430227 |
FM in-band-on-channel digital audio broadcasting method and system |
August 6, 2002 |
| This invention provides a method of broadcasting including the steps of providing a broadcast signal in a central frequency band of an FM radio channel; providing a first plurality of sub-carriers in an upper sideband of the FM radio channel; providing a second plurality of sub-carriers |
| 6400758 |
Method and apparatus for training sequence identification in an AM compatible digital audio broa |
June 4, 2002 |
| A method is provided for identifying a training baud in a digital audio broadcasting signal. The method includes the steps of receiving a plurality of carrier signals modulated by a plurality of data baud, wherein the data baud include normal baud and training baud. The data baud rec |
| 6345377 |
Digital audio broadcasting method using puncturable convolutional code |
February 5, 2002 |
| A broadcasting method comprising the steps of encoding program material using codes including a first set of bits and a second set of bits, the first set of bits contributing a greater coding gain to the codes than the second set of bits, modulating a plurality of orthogonal frequency |
| 6317470 |
Adaptive weighting method for orthogonal frequency division multiplexed soft symbols using chann |
November 13, 2001 |
| A method for weighting orthogonal frequency division multiplexed soft symbols is provided, including the steps of receiving a plurality of sub-carriers modulated by digital information and filtering the sub-carriers to produce complex soft decision outputs. The magnitudes of the soft |
| 6259893 |
Method and apparatus for reduction of FM interference for FM in-band on-channel digital audio br |
July 10, 2001 |
| 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 |
| 6178317 |
System and method for mitigating intermittent interruptions in an audio radio broadcast system |
January 23, 2001 |
| A system (100) 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 frequ |
