Patents by Inventor Brian William Kroeger

Brian William Kroeger has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8442170
    Abstract: A method is provided for equalizing OFDM symbol vectors received on AM in-band on-channel radio signal including a main carrier and first and second BPSK modulated subcarriers. The method comprises the steps of: computing a BPSK magnitude signal; filtering the BPSK magnitude signal; filtering complex samples received on the main carrier; using the filtered BPSK magnitude signal and the filtered complex samples received on the main carrier to compute a plurality of flat fade equalization coefficients; and multiplying the OFDM symbol vectors by the flat fade equalization coefficients. A receiver that includes an equalizer, which operates in accordance with the method is also provided.
    Type: Grant
    Filed: February 23, 2010
    Date of Patent: May 14, 2013
    Assignee: iBiquity Digital Corporation
    Inventors: Brian William Kroeger, Kun Wang
  • Patent number: 8068800
    Abstract: A method of tuning an antenna circuit includes: (a) receiving a signal on an antenna, (b) producing a received signal strength indication based on the received signal, (c) using the received signal strength indication to produce a control voltage, (d) using the control voltage to control a capacitance in an antenna matching circuit, (e) changing the control voltage to minimize a ratio of a change in the received signal strength indication to a change in the control voltage and (f) repeating steps (a), (b), (c), (d) and (e). An apparatus that implements the method is also provided.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: November 29, 2011
    Assignee: iBiquity Digital Corporation
    Inventors: Brian William Kroeger, Paul James Peyla, Jeremy Daniel Gotwalt, Libin Wang, Dean Anthony Telson
  • Patent number: 8027419
    Abstract: This invention provides a method of detecting time alignment of an analog audio signal and a digital audio signal in a hybrid radio system. The method comprises the steps of filtering the analog audio signal to produce a filtered analog audio signal, filtering the digital audio signal to produce a filtered digital audio signal, and using the filtered analog audio signal and the filtered digital audio signal to calculate a plurality of correlation coefficients, wherein the correlation coefficients are representative of time alignment between the analog audio signal and the digital audio signal. An apparatus for performing the method is also provided.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: September 27, 2011
    Assignee: iBiquity Digital Corporation
    Inventors: Russell Iannuzzelli, Brian William Kroeger, Harvey Chalmers
  • Patent number: 7982683
    Abstract: An apparatus includes first and second speakers, and an antenna including a first pair of wires connected to the first speaker, a second pair of wires connected to the second speaker, and a conductive sleeve surrounding portions of the first and second pairs of wires, the sleeve forming a coaxial capacitor with the first and second pairs of wires. The apparatus can further include an inductor connected between the first and second pairs of wires and the sleeve, to form a resonant circuit with the coaxial capacitor.
    Type: Grant
    Filed: September 26, 2007
    Date of Patent: July 19, 2011
    Assignee: iBiquity Digital Corporation
    Inventors: Paul J. Peyla, Brian William Kroeger
  • Patent number: 7933367
    Abstract: A method for detecting a digital radio signal includes the steps of receiving the digital radio signal, developing a correlation waveform having a peak that corresponds to a symbol boundary, normalizing the correlation waveform, calculating a peak value of the normalized correlation waveform, and dwelling on the received digital radio signal when the peak value exceeds a predetermined threshold. A receiver that performs the method is also provided.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: April 26, 2011
    Assignee: iBiquity Digital Corporation
    Inventors: Brian William Kroeger, Paul J. Peyla
  • Patent number: 7933368
    Abstract: A method for detecting a digital radio signal includes the steps of receiving the digital radio signal including a series of symbols, developing a correlation waveform having a peak that corresponds to a symbol boundary, normalizing the correlation waveform, and calculating a peak value of the normalized correlation waveform, wherein the peak value represents the quality of the received digital radio signal. A receiver that performs the method is also provided.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: April 26, 2011
    Assignee: iBiquity Digital Corporation
    Inventors: Paul J. Peyla, Brian William Kroeger
  • Patent number: 7873120
    Abstract: A method of broadcasting an AM compatible digital audio broadcasting signal includes: producing an analog modulated carrier signal centrally positioned in a radio channel, wherein the analog modulated carrier signal is modulated by an analog signal, producing a plurality of digitally modulated subcarrier signals in the radio channel, wherein the digitally modulated subcarrier signals are modulated using complementary pattern-mapped trellis code modulation (CPTCM) including a code mapped to overlapping partitions including an upper main partition, a lower main partition, an upper backup partition and a lower backup partition, and a non-overlapping tertiary partition, and transmitting the analog modulated carrier signal and the plurality of digitally modulated subcarrier signals. Transmitters that broadcast the signal and receivers that receive the signal, and the reception method are also included.
    Type: Grant
    Filed: January 11, 2010
    Date of Patent: January 18, 2011
    Assignee: iBiquity Digital Corporation
    Inventor: Brian William Kroeger
  • Publication number: 20100215090
    Abstract: A method is provided for equalizing OFDM symbol vectors received on AM in-band on-channel radio signal including a main carrier and first and second BPSK modulated subcarriers. The method comprises the steps of: computing a BPSK magnitude signal; filtering the BPSK magnitude signal; filtering complex samples received on the main carrier; using the filtered BPSK magnitude signal and the filtered complex samples received on the main carrier to compute a plurality of flat fade equalization coefficients; and multiplying the OFDM symbol vectors by the flat fade equalization coefficients. A receiver that includes an equalizer, which operates in accordance with the method is also provided.
    Type: Application
    Filed: February 23, 2010
    Publication date: August 26, 2010
    Applicant: iBiquity Digital Corporation
    Inventors: Brian William Kroeger, Kun Wang
  • Publication number: 20100144295
    Abstract: A method of tuning an antenna circuit includes: (a) receiving a signal on an antenna, (b) producing a received signal strength indication based on the received signal, (c) using the received signal strength indication to produce a control voltage, (d) using the control voltage to control a capacitance in an antenna matching circuit, (e) changing the control voltage to minimize a ratio of a change in the received signal strength indication to a change in the control voltage and (f) repeating steps (a), (b), (c), (d) and (e). An apparatus that implements the method is also provided.
    Type: Application
    Filed: December 10, 2008
    Publication date: June 10, 2010
    Applicant: iBiquity Digital Corporation
    Inventors: Brian William Kroeger, Paul James Peyla, Jeremy Daniel Gotwalt, Libin Wang, Dean Anthony Telson
  • Patent number: 7733983
    Abstract: A method for symbol tracking in AM in-band on-channel radio receivers comprises the steps of: receiving a stream of time domain samples; assembling a set of the time domain samples equal to a symbol time plus a half symbol delay in response to a symbol timing adjustment value for each symbol period; interpolating the time domain samples; partitioning the interpolated time domain samples into a first group of samples representing half-off symbols and a second group of samples representing on-time symbols; processing the first and second groups of samples to produce the symbol timing adjustment value; and outputting the second group of samples representing on-time symbols at a symbol rate. An apparatus that performs the method is also included.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: June 8, 2010
    Assignee: iBiquity Digital Corporation
    Inventors: Brian William Kroeger, Kun Wang
  • Publication number: 20100111225
    Abstract: A method of broadcasting an AM compatible digital audio broadcasting signal includes: producing an analog modulated carrier signal centrally positioned in a radio channel, wherein the analog modulated carrier signal is modulated by an analog signal, producing a plurality of digitally modulated subcarrier signals in the radio channel, wherein the digitally modulated subcarrier signals are modulated using complementary pattern-mapped trellis code modulation (CPTCM) including a code mapped to overlapping partitions including an upper main partition, a lower main partition, an upper backup partition and a lower backup partition, and a non-overlapping tertiary partition, and transmitting the analog modulated carrier signal and the plurality of digitally modulated subcarrier signals. Transmitters that broadcast the signal and receivers that receive the signal, and the reception method are also included.
    Type: Application
    Filed: January 11, 2010
    Publication date: May 6, 2010
    Applicant: iBiquity Digital Corporation
    Inventor: Brian William Kroeger
  • Patent number: 7706474
    Abstract: A method for carrier tracking in AM in-band on-channel radio receivers comprises the steps of receiving an input signal, generating a local oscillator signal in response to an oscillator control signal, mixing the input signal with a local oscillator signal to produce a first signal, filtering the first signal to produce a filtered first signal at a decimated sample rate, detecting the phase error and frequency error of the filtered first signal normalized to mitigate effects of signal fades, and using an adaptive loop filter to produce the oscillator control signal in response to the phase error and frequency error of the filtered first signal. An apparatus that performs the method is also provided.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: April 27, 2010
    Assignee: iBiquity Digital Corporation
    Inventors: Brian William Kroeger, Kun Wang
  • Patent number: 7706468
    Abstract: A transmitter for broadcasting an AM compatible digital audio broadcasting signal includes an analog modulator for producing 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 digital modulator for producing a plurality of digitally modulated subcarrier signals in the radio channel, wherein the digitally modulated subcarrier signals are modulated using complementary pattern-mapped trellis code modulation including a code mapped to overlapping partitions. In a first operating mode the analog modulated carrier signal and the plurality of digitally modulated subcarrier signals are in a 20 kHz channel and in a second operating mode the analog modulated carrier signal and the plurality of digitally modulated subcarrier signals are in a 30 kHz channel.
    Type: Grant
    Filed: February 22, 2008
    Date of Patent: April 27, 2010
    Assignee: iBiquity Digital Corporation
    Inventor: Brian William Kroeger
  • Patent number: 7697620
    Abstract: A method is provided for equalizing OFDM symbol vectors received on AM in-band on-channel radio signal including a main carrier and first and second BPSK modulated subcarriers. The method comprises the steps of: computing a BPSK magnitude signal; filtering the BPSK magnitude signal; filtering complex samples received on the main carrier; using the filtered BPSK magnitude signal and the filtered complex samples received on the main carrier to compute a plurality of flat fade equalization coefficients; and multiplying the OFDM symbol vectors by the flat fade equalization coefficients. A receiver that includes an equalizer, which operates in accordance with the method is also provided.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: April 13, 2010
    Assignee: iBiquity Digital Corporation
    Inventors: Brian William Kroeger, Kun Wang
  • Patent number: 7680201
    Abstract: A method of broadcasting an AM compatible digital audio broadcasting signal includes: producing an analog modulated carrier signal centrally positioned in a radio channel, wherein the analog modulated carrier signal is modulated by an analog signal, producing a plurality of digitally modulated subcarrier signals in the radio channel, wherein the digitally modulated subcarrier signals are modulated using complementary pattern-mapped trellis code modulation (CPTCM) including a code mapped to overlapping partitions including an upper main partition, a lower main partition, an upper backup partition and a lower backup partition, and a non-overlapping tertiary partition, and transmitting the analog modulated carrier signal and the plurality of digitally modulated subcarrier signals. Transmitters that broadcast the signal and receivers that receive the signal, and the reception method are also included.
    Type: Grant
    Filed: February 4, 2008
    Date of Patent: March 16, 2010
    Assignee: iBiquity Digital Corporation
    Inventor: Brian William Kroeger
  • Patent number: 7551675
    Abstract: 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 absolute time reference, and transmitting the output frames to a plurality of receivers. Transmitters that broadcast in accordance with the method and receivers that receive the transmitted signal are also disclosed. A method is also provided for receiving digital audio broadcasting signals comprising the steps of receiving a digital audio broadcasting signal comprising a plurality of output frames of information, wherein each of the output frames includes a plurality of blocks of data and each of the output frames is synchronized with an absolute time reference, and determining the start of each output frame relative to an absolute time reference.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: June 23, 2009
    Assignee: iBiquity Digital Corporation
    Inventor: Brian William Kroeger
  • Patent number: 7542517
    Abstract: 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 signal, demodulating the first limited modulated signal to recover distorted input symbol vectors, constraining the distorted input symbol vectors to values greater than or equal to a minimum threshold value to produce constrained data symbol vectors, constraining out-of-band spectral components to lie within a predetermined mask, and remodulating the constrained data symbol vectors. A transmitter that performs the method is also included.
    Type: Grant
    Filed: February 2, 2004
    Date of Patent: June 2, 2009
    Assignee: iBiquity Digital Corporation
    Inventor: Brian William Kroeger
  • Patent number: 7512175
    Abstract: 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 pulses is controlled by a modem frame clock, producing an exciter clock signal, counting pulses representative of the exciter clock signal to produce a count representative of timing error of each incoming modem frame pulse, and controlling the exciter clock signal in response to the count. An apparatus that performs the method is also provided.
    Type: Grant
    Filed: March 16, 2005
    Date of Patent: March 31, 2009
    Assignee: iBiquity Digital Corporation
    Inventor: Brian William Kroeger
  • Publication number: 20090079656
    Abstract: An apparatus includes first and second speakers, and an antenna including a first pair of wires connected to the first speaker, a second pair of wires connected to the second speaker, and a conductive sleeve surrounding portions of the first and second pairs of wires, the sleeve forming a coaxial capacitor with the first and second pairs of wires. The apparatus can further include an inductor connected between the first and second pairs of wires and the sleeve, to form a resonant circuit with the coaxial capacitor.
    Type: Application
    Filed: September 26, 2007
    Publication date: March 26, 2009
    Inventors: Paul J. Peyla, Brian William Kroeger
  • Patent number: 7474707
    Abstract: 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 demodulated baseband multiplex signal, correcting the demodulated baseband multiplex signal to reduce or eliminate distortion in a predetermined frequency range of the demodulated baseband multiplex signal to produce a corrected signal, and frequency modulating the corrected signal to produce a second modulated signal. An apparatus that operates in accordance with the method is also provided.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: January 6, 2009
    Assignee: iBiquity Digital Corporation
    Inventor: Brian William Kroeger