A method for processing a digital audio broadcast signal includes: separating an analog audio portion and a digital audio portion of the digital audio broadcast signal; determining the loudness of the analog audio portion and the digital audio portion over a first short time interval; using the loudness of the analog and digital audio portions to calculate a short term average gain; determining a long term average gain; converting one of the long term average gain or the short term average gain to dB; if an output has been blended to digital, adjusting a digital gain parameter by a preselected increment to produce a digital gain parameter; if an output has not been blended to digital, setting the digital gain parameter to the short term average gain; providing the digital gain parameter to an audio processor; and repeating the above steps using a second short time interval.

A boundary specifying a bounded geographic area for which travel information is to be reported is generated. Flow section information associated with flow sections located within the boundary is obtained. The flow sections represent portions of one or more roadways assigned relevant functional road classes (FRCs). The flow section information includes information about traffic flow associated with the flow sections. FRC current traffic messages, which include non-predictive traffic information associated with roadway portions that are in the bounded geographic area and are assigned relevant FRCs, are combined with the flow section information to generate a first data group. The first data group is streamed to a first traffic message service.

A method is provided that comprises tuning a radio system to a frequency band that contains a locally-broadcast terrestrial radio signal. The locally-broadcast terrestrial radio signal comprising a main signal component and a side data component is thereby received. In response to receiving the locally-broadcast terrestrial radio signal a determination is made as to a permissible time for processing the side data component using a time slot schedule. The side data component is processed at the permissible time. A message corresponding to the side data component is outputted to an output device. In some instances, the side data component includes the message. In other instances, the method further includes searching a message lookup list using a code included in the side data component. When a stored code is found that matches the code, the message corresponding to the matching stored code is outputted.

A method for processing a radio signal includes producing first and second streams of audio samples; decimating the first and second streams of audio samples to produce first and second streams of decimated streams of audio samples; estimating a first offset value between corresponding samples in the first and second streams of decimated streams of audio samples; shifting one of the first and second streams of audio samples by a first shift value; decimating the first and second streams of audio samples to produce third and fourth streams of decimated audio samples; estimating a second offset value; determining a final offset value based on an intersection of ranges of valid results of the first and second offset values; and shifting one of the first and second streams of audio samples by the final offset value to align the first and second streams of audio samples.

A method and apparatus are provided for blending analog and digital portions of a composite digital radio broadcast signal by processing compressed audio packets to compute corresponding digital audio quality indicator values, storing the compressed audio packets in an audio blend buffer, processing audio information from each compressed audio packet stored in the audio blend buffer with an audio decoder to generate decompressed digital audio signal samples, and using the digital audio quality indicator values to guide a blending process for combining analog audio signal samples with the digital audio signal samples to produce an audio output by preventing unnecessary blending back and forth between analog and digital if the digital audio quality indicator values indicate that the compressed audio packets are degraded or impaired.

A method of processing a digital radio broadcast signal in a digital radio receiver includes: receiving baseband signal samples at a first sample rate; adjusting the sample rate of the baseband signals based on a difference between a receiver clock and a transmitter clock to produce adjusted baseband signal samples at a second sample rate; filtering the adjusted baseband signal samples to separate a digital component of the samples and an analog component of the samples, wherein the digital component and the analog component are synchronous; and separately demodulating the digital component and the analog component to produce a digital output signal and an analog output signal. A receiver that uses the method is also provided.

Systems and methods are described for rendering content at a digital radio broadcast receiver system. A digital radio broadcast signal comprises data for rendering content at the digital radio broadcast receiver. The digital radio broadcast signal is processed to determine whether the data from the digital radio broadcast transmission contains a data error. A portion of the data containing the data error is identified. A download request is transmitted to a computing system, where the download request requests duplicate data for the portion of the data containing the data error. The duplicate data is received at the digital radio broadcast receiver for the portion of the data containing the error via other wireless communication other than the digital radio broadcast. The duplicate data is processed to provide an uninterrupted rendering of the content.

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.

Described herein are systems, methods and apparatus for decoding in-band on-channel signals and extracting audio and data signals. Memory requirements are reduced by selectively filtering a bit stream of data in the signal so that services of interest which are encoded therein are processed. A single pool of memory may be shared between physical layer and data link layer processing. Memory in this pool may be allocated dynamically between processing of data at the physical and data link layers. When the available memory is not sufficient to support the required services, the dynamic allocation allows for graceful degradation.

Embodiments of a method and system for transmitting an audio stream and a digital radio broadcasting system are disclosed. The method comprises providing an audio source remotely located to a digital radio broadcasting system. encoding at the audio source an audio stream with an audio codec resulting in an encoded audio stream, transmitting the encoded audio stream over a computer network to the digital radio broadcasting system. receiving the encoded audio stream and processing the encoded audio stream at the digital radio broadcasting system for broadcast by the digital radio broadcasting system without decoding of the encoded audio stream, and broadcasting the encoded audio stream by the digital radio broadcasting system.