Ibiquity Digital Corporation

Other

Cbs Corporation

Paul James Peyla

Brian William Kroeger

Jeffrey Scott Baird

Denise Maureen Cammarata

Joseph Bertram Bronder

Steven L Teig

Gadiel Seroussi

George Nicholas Eberl

E Glynn Walden

Richard Edward Martinson

Jeremy Daniel Gotwalt

Libin Wang

Dean Anthony Telson

Gregory W Seker

Jeffrey S Baird

A method comprises performing iterations of a peak-to-average ratio (PAR) reduction algorithm on a modulated OFDM symbol, each of the iterations including: clipping the modulated OFDM symbol to produce a clipped modulated OFDM symbol; subtracting the clipped modulated OFDM symbol from the modulated OFDM symbol to produce a difference signal; weighting the difference signal using a weight that varies across the iterations, to produce a weighted difference signal that varies across the iterations; subtracting the weighted difference signal from the modulated OFDM symbol to produce a modified modulated OFDM symbol; and performing further PAR reduction operations on the modified modulated OFDM symbol to produce a PAR-reduced OFDM symbol for use in a next iteration.

In peak-to-average power ratio reduction and processing efficiency for hybrid/digital signals

A method comprises partitioning a data object into a sequence of nested data objects each including fragments having K symbols per fragment. The method further comprises processing the nested data objects to produce sequences of coded payloads corresponding to the nested data objects. The processing includes, for each nested data object: using (n, K) coding for which n>K, individually coding the fragments of the nested data object into codewords with n codeword symbols per codeword; and generating, from the codewords, a sequence of coded payloads that are unique for the nested data object. The method further comprises transmitting coded payloads of the sequences of coded payloads.

Efficient large object transport

A method for processing a digital audio broadcast signal in a radio receiver, includes: receiving a hybrid broadcast signal; demodulating the hybrid broadcast signal to produce an analog audio stream and a digital audio stream; and using a normalized cross-correlation of envelopes of the analog audio stream and the digital audio stream to measure a time offset between the analog audio stream and the digital audio stream. The time offset can be used to align the analog audio stream and the digital audio stream for subsequent blending of an output of the radio receiver from the analog audio stream to the digital audio stream or from the digital audio stream to the analog audio stream.

Time-alignment measurement for hybrid HD radio&#x2122; technology

A method for processing audio signals in a radio transmitter, includes: receiving an analog audio sample stream and a digital audio sample stream; determining offsets in time between the analog audio stream and the digital audio stream using a normalized cross-correlation of audio envelopes of the analog audio sample stream and the digital audio sample stream; filtering the determined offsets in time to produce filtered offset values; determining an alignment slip adjustment value as a function of the filtered offset values; aligning the analog audio sample stream and the digital audio sample stream using the determined alignment slip adjustment value; and generating a hybrid radio signal for broadcast that includes time-aligned analog audio and digital audio.

A method comprises receiving an approximate location of a rover platform based on satellite signals for a Global Navigation Satellite System (GNSS), and receiving for the GNSS a differential correction map (DCM) representing a non-planar surface of differential corrections that varies across a geographical area represented by the DCM. The differential corrections are based on a reference station constellation of GNSS reference stations having respective locations spanning the geographical area. The method further comprises deriving DCM-based differential corrections for the satellite signals at the approximate location based on the DCM, correcting the satellite signals using the DCM-based differential corrections, and determining a location of the rover platform using the corrected satellite signals.

Differential correction map for GNSS

A method comprises generating for a Global Navigation Satellite System (GNSS) a differential correction map (DCM) representing a non-planar surface of differential corrections that varies across a geographical area represented by the DCM, the differential corrections being based on a reference station constellation of GNSS reference stations having respective locations spanning the geographical area, the GNSS reference stations including physical or virtual reference stations.

A radio transmitter comprises transmitting circuitry and processing circuitry. The transmitting circuitry broadcasts a frequency modulation (FM) in-band on-channel (IBOC) radio signal, wherein the FM IBOC radio signal includes multiple subcarriers grouped into multiple frequency partitions. The processing circuitry is configured to receive input bits for transmitting; encode and puncture the input bits using forward error correction (FEC) encoding; distribute encoded input bits between a main encoded component and a backup encoded component, wherein encoded bits of the backup encoded component are delayed for a specified duration relative to encoded bits of the main encoded component; allocate the encoded input bits of the main and backup encoded components into frequency diverse sidebands of the FM IBOC radio signal; and modulate the encoded input bits for transmitting using the frequency diverse sidebands of the FM IBOC radio signal, wherein the modulation is a type of quadrature amplitude modulation (QAM).

Lumb service modes for FM HD radio broadcasts

Time-alignment measurement for hybrid HD radio technology

A radio receiver comprises physical layer circuitry and processor circuitry. The physical layer circuitry receives quadrature amplitude modulation (QAM) symbols via a plurality of subcarriers included in a broadcast radio signal. Each received QAM symbol is a complex symbol comprising multiple bits of encoded source information. The processing circuitry demodulates the received data symbols, generates a constellation sample for each received QAM symbol, generates a soft metric for each bit of encoded information of the received QAM symbols using the constellation sample, and multiplies the soft metric by a channel state information (CSI) weight to produce a Log-likelihood Ratio (LLR) approximation for each bit of encoded information of the received QAM symbols.

CSI estimation and LLR approximation for QAM demodulation in FM HD radio receivers

A method for processing a digital signal includes: receiving a plurality of protocol data units, each having a header including a plurality of control word bits; and a plurality of audio frames, each including a cyclic redundancy check code; decoding the protocol data units using an iterative decoding technique, wherein the iterative decoding technique uses a soft output decoding algorithm for iterations after the first iteration; and using decoded cyclic redundancy check codes to flag the audio frames containing errors. A receiver that implements the method is also provided.

Iterative forward error correction decoding for FM In-Band On-Channel radio broadcasting systems

Time-alignment measurment for hybrid HD radio technology

A method for processing a digital audio broadcast signal in a radio receiver includes: receiving a digital audio broadcast signal; demodulating the digital audio broadcast signal to produce an analog audio stream and a digital audio stream; determining a digital signal quality value for the digital audio stream; blending an output of the radio receiver from the analog audio stream to the digital audio stream when the digital signal quality value exceeds an adaptive analog-to-digital threshold value; and blending the output of the radio receiver from the digital audio stream to the analog audio stream when the digital signal quality value falls below an adaptive digital-to-analog threshold value, wherein the adaptive digital-to-analog threshold value is lower than the adaptive analog-to-digital threshold value.

Method and apparatus for blending an audio signal in an in-band on-channel radio system

A method includes: receiving an FM radio signal including an analog-modulated portion; digitally sampling an analog-modulated portion of the radio signal to produce a plurality of samples; using a ratio between an average magnitude and an RMS magnitude of a block of the samples to compute a signal quality metric; detecting sum and difference components of the baseband multiplex signal content; using the baseband content to produce an output signal; and blending the output signal from stereo to monaural as the signal quality metric falls below a threshold value.

FM analog demodulator compatible with IBOC signals

A method for detecting the digital quality of a radio signal includes: receiving a radio signal including an analog modulated portion; digitally sampling an analog modulated portion of the radio signal to produce a plurality of samples; using a ratio between an average magnitude and an RMS magnitude of a block of the samples to compute an analog signal quality metric. Receivers that implement the method are also provided.

Growing community of inventors

Elkridge, MD, United States of America

Paul James Peyla