Abstract: Methods and systems for adjusting a sampling rate of a digital radio receiver are disclosed that comprise the steps of receiving from a decoder a first frame of data having a first number of samples; determining at the digital radio receiver a phase difference between a receiver clock and a transmitter clock; generating at the digital radio receiver a second frame of data having a second number of samples, wherein the second number of samples depends on the phase difference between the receiver clock and the transmitter clock such that the second number of samples is less than the first number of samples if the transmitter clock is ahead of the receiver clock, and the second number of samples is greater than the first number of samples if the receiver clock is ahead of the transmitter clock; outputting the second frame of data having the second number of samples; and requesting a next frame of data from the decoder at a time that is earlier than a processing time for the first number of samples if the transmi

Abstract: A method of managing radio broadcasting services includes: generating a broadcast token including information for associating a service with one or more subscriber groups, using the broadcast token to configure a transmission of the service by a broadcaster, and broadcasting the service to the subscriber group. At the broadcaster, the service can be configured by using parameters in the broadcast token to retrieve service content from a resource manager.

Abstract: Methods and systems for preparing data for broadcast via digital radio broadcast transmission is disclosed comprising the steps of receiving a plurality of content files corresponding to programming information for program content to be broadcast; receiving an index file having a pointer for each of the plurality of content files, wherein the index file is associated with a first logical address; storing the index file and the plurality of content files; scheduling a broadcast rotation of the index file and the plurality of content files (wherein the index file is scheduled for repeated transmission intermittently relative to selected ones of the content files); and transmitting the index file and the plurality of content files to an importer in accordance with the broadcast rotation.

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.

Abstract: An apparatus for controlling a data rate in a data client for a digital audio broadcasting system includes a buffer for storing data, a codec for coding data, and a control module for controlling a bit rate of the codec in response to a level of the data in the buffer. A method performed by the apparatus is also included.

Abstract: 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 audio portion of the digital audio broadcast signal, detecting errors in the digital audio portion of the digital audio broadcast signal, adjusting the digital audio portion of the digital audio broadcast signal in response to errors in the digital audio portion of the digital audio broadcast signal to produce an adjusted digital audio portion, and blending the analog audio portion with the adjusted digital audio portion to produce an audio output. A receiver that performs the method is also included.

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.

Abstract: A method for rendering an alert message on a digital radio broadcast receiver is described. A digital radio broadcast signal is received at the digital radio broadcast receiver. Data corresponding to an alert message comprising type information for identifying a type of the alert message and message information is detected. If the type information satisfies a triggering condition for a type of alert message pre-selected by a user of the digital radio broadcast receiver, the message information is rendered at the digital radio broadcast receiver. A digital radio broadcast receiver that performs the method is also described.

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.

Abstract: A method includes: receiving a plurality of audio frames, assembling groups of the audio frames into logical recording units, storing a plurality of the logical recording units, retrieving the stored logical recording units, and decoding the retrieved logical recording units. An apparatus that performs the method is also provided.

Abstract: 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.

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.

Abstract: 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 transmitting the bits of digital information. The step of forward error correcting the bits of digital information can comprise the steps of representing the bits as independently coded in-phase and quadrature signals, applying a first error correcting code to the in-phase signals, and applying a second error correcting code to the quadrature signals. The bits of digital information can be arranged in a plurality of partitions of code, wherein first and second ones of the partitions do not overlap, a third one of the partitions overlaps a first portion of the first and second partitions, and a fourth one of the partitions overlaps a second portion of the first and second partitions.

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.

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.

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.

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.

Abstract: A method is provided for receiving and processing a digital radio broadcasting signal. The method includes the steps of receiving a digital radio broadcasting signal including content, storing encoded content, and decoding the stored encoded content to recover decoded content. The stored encoded content can include protocol data units or packets. The stored encoded content can be recovered by decoding the encoded content according to a logical protocol stack.

Abstract: An apparatus includes a network receiver for receiving an over-the-air in-band on-channel broadcast signal and extracting broadcast content from the broadcast signal, and an output for delivering the content by way of a first receiver output signal to a plurality of network player devices. A method performed by the apparatus is also included.

Abstract: 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, wherein at least one of the writing and reading steps follows a non-sequential addressing scheme. Apparatus for transmitting the interleaved bits, and apparatus for receiving and deinterleaving the bits are also provided.