Ibiquity Digital Corporation

Comsat Corporation

Harvey Chalmers

Russell Iannuzzelli

Joseph F D'Angelo

Steven Andrew Johnson

Robert Michael Dillon

Stephen Douglas Mattson

Jeffrey Ranken Detweiler

Paul Venezia

Muthu Gopal Balasubramanian

Desmond S Fuller

Brian William Kroeger

Girish Warrier

Rodney Burke

Ajit Shenoy

Albert John Gambardella

Joseph F D'angelo

Rodney Bernard Burke

Thomas Joseph O'brien

Gregory R Nungester

Robert Michaels

Thomas Joseph O'Brien

Albert D Shuldiner

Michael R Raide

Farhad B Verahrami

Russ Mundschenk

Girish K Warrier

Brian W Kroeger

Systems, methods, and processor readable media are disclosed for detection of signal quality problems and errors in digital radio broadcast signals. First monitoring equipment is located in an over-the-air coverage area of a first radio station. Second monitoring equipment is located in an over-the-air coverage area of a second radio station. The first and second monitoring equipment are configured to receive digital radio broadcast signals from the respective first and second radio stations. A computing system is configured to receive data from the first monitoring equipment and the second monitoring equipment, the data being indicative of one or more attributes of a digital radio broadcast signal received at respective monitoring equipment. The computing system analyzes received data to detect a signal quality problem or error in the digital radio broadcast signals received at the first and second monitoring equipment.

Systems and methods for detection of signal quality in broadcast signals

Systems and methods for detection of signal quality in digital radio broadcast signals

A peak-to-average power reduction method includes: (a) quadrature amplitude modulating a signal including a set of subcarriers with a set of data to produce an OFDM modulated symbol vector; (b) limiting the magnitude of the modulated symbol vector to produce a first limited OFDM modulated symbol; (c) demodulating the first limited OFDM modulated symbol to recover distorted QAM constellations; (d) constraining points in the distorted QAM constellations recovered from the first limited OFDM modulated symbol to produce constrained QAM constellations; (e) modulating an OFDM symbol vector with the constrained QAM constellations to produce a modified modulated OFDM symbol; and (f) output the modified modulated OFDM symbol. A transmitter that implements the method is also provided.

Peak-to-average power ratio reduction for QAM modulation with HD radio signals

Systems, methods, and processor readable media are disclosed for encoding and transmitting first media content and second media content using a digital radio broadcast system, such that the second media content can be rendered in synchronization with the first media content by a digital radio broadcast receiver. The disclosed systems, methods, and processor-readable media determine when a receiver will render audio and data content that is transmitted at a given time by the digital radio broadcast transmitter, and adjust the media content accordingly to provide synchronized rendering. In exemplary embodiments, these adjustments can be provided by: 1) inserting timing instructions specifying playback time in the secondary content based on calculated delays; or 2) controlling the timing of sending the primary or secondary content to the transmitter so that it will be rendered in synchronization by the receiver.

Systems and methods for transmitting media content via digital radio broadcast transmission for synchronized rendering by a receiver

A method for specifying content of interest using a digital radio broadcast receiver is described. A digital radio broadcast signal includes first audio content and first program data, wherein the first program data includes information identifying a first item, and includes second audio content and second program data, wherein the second program data includes information identifying a second item. A user command entered at a user interface during reception of audio content is registered, indicating a user's interest in either the first or second audio content. It is determined whether there is an ambiguity in the content of interest. If there is an ambiguity, a first data structure is stored for the first audio content, and a second data structure is stored for the second audio content. The first data structure includes the information identifying the first item, and the second data structure includes the information identifying the second item.

Digital radio broadcast receiver, broadcasting methods and methods for tagging content of interest

A digital radio broadcast system includes a processing system that receives first audio content, first program data identifying a first item for the first audio content, second audio content, and second program data identifying a second item for the second audio content such that a start of the first program data is received at the processing system within 0.5 seconds of a start of the first audio content. A digital radio broadcast signal including the audio content and the program data is processed for digital radio broadcast transmission via a transmitter. The processing system stops delivery of the first program data to the transmitter upon receipt of the second program data, the first program data thereby being truncated, and begins delivery of the second program data to the transmitter. A digital radio broadcast receiver can tag content of interest based on a user command registered at the receiver.

Systems, methods, and processor readable media are disclosed for scheduling and delivering content for digital radio broadcast transmission. To overcome the inefficiencies of conventional scheduling and delivery techniques, the present disclosure describes a novel multiport synchronous-asynchronous client for receiving content from multiple sources and then scheduling and delivering that content to an importer.

Systems and methods for a multiport synchronous-asynchronous client for scheduling and delivering content for digital radio broadcast transmission

Systems, methods, and processor readable media are disclosed for encoding and transmitting first media content, second media content and triggering instructions to a digital radio broadcast receiver such that the triggering instructions arrive for immediate execution to trigger immediate rendering of the second media content in synchronization with the first media content.

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.

Method for alignment of analog and digital audio in a hybrid radio waveform

A signal generator includes a memory for storing content information in the form of vectors including in-phase and quadrature elements of an orthogonal frequency division multiplexing waveform, a processor for converting the vectors to a radio frequency signal, and a logic device for controlling the operation of the memory and the processor. The in-phase and quadrature elements represent baseband content of the orthogonal frequency-division multiplexing waveform.

Radio signal generator

Digital downconverter/despreader for direct sequence spread spectrum

A satellite communication system including a portable satellite terminal is provided which utilizes C/K.sub.u -band and spread spectrum technology to drastically reduce the antenna and terminal sizes. Both CDMA and time division multiplexing (TDM) are used to permit efficient all-digital voice, facsimile and data operations in either full mesh or star modes. A single Network Controller can handle both Star and Mesh mode traffic on the same or several transponders. Narrowband CDMA/frequency division multiple access is used for inbound transmission from the terminal while outbound transmissions from the hub utilize TDM/FDMA. Furthermore, the system is scalable in fixed bandwidth increments to support network size evolution. All signalling for call setup and takedown is done in-band on the same carrier that is used for the traffic, thereby eliminating the need for a separate signalling channel and frequency retuning. Only a small set of distinct PN code sequences, independent of the actual number of user terminals in the network, are required for the entire network.

Growing community of inventors

Rockville, MD, United States of America

Harvey Chalmers