A system includes a processor configured to determine that transmission data indicates that first data was transmitted via a digital radio channel and that reception data indicates that second data was received via the digital radio channel. The first data is transmitted concurrently with transmission of an analog signal. The processor is configured to detect an error in transmission of the first data based on a comparison of adjacent portions of the first data to non-adjacent portions of the second data. The processor is configured to, in response to detecting the error, initiate display of a default image concurrently with output of an audio signal that is based on the analog signal and to initiate retransmission of the first data to cause second particular data to be output subsequent to the output of the default image. The second particular data corresponds to the retransmitted first data.

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 demodulation apparatus according to the present disclosure includes an analog audio demodulator, a digital audio demodulator, a selection circuit, and a noise addition circuit. The analog audio demodulator demodulates a received signal of an analog radio broadcast wave into an analog audio signal and outputs the analog audio signal. The digital audio demodulator demodulates a received signal of a digital radio broadcast wave into a digital audio signal and outputs the digital audio signal, the analog/digital radio broadcast waves including audio signals indicative of a same content and being broadcasted simultaneously. The selection circuit selects either the analog audio signal or the digital audio signal. The noise addition circuit adds noise to the digital audio signal in a first period including a switching period for switching from a state where the analog audio signal is selected to a state where the digital audio signal is selected.

During normal operation, a switching module receives, from one or more media encoders, channel content associated with one or more media channels and transmits that channel content to a transmitter. The switching module, while transmitting the channel content, logs in a notification system in response to a login request received from the notification system. Once logged in, the notification system transmits content associated with the one or more media channels to the switching module. The switching module transmits the notification content to the transmitter in place of the channel content received from the media encoders. While transmitting the notification content, the switching module determines that the notification system has been logged out, and resumes transmission of the channel content to the transmitter.

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 demodulation apparatus according to the present disclosure includes an analog audio demodulator, a digital audio demodulator, a selection circuit, and a noise addition circuit. The analog audio demodulator demodulates a received signal of an analog radio broadcast wave into an analog audio signal and outputs the analog audio signal. The digital audio demodulator demodulates a received signal of a digital radio broadcast wave into a digital audio signal and outputs the digital audio signal, the analog/digital radio broadcast waves including audio signals indicative of a same content and being broadcasted simultaneously. The selection circuit selects either the analog audio signal or the digital audio signal. The noise addition circuit adds noise to the digital audio signal in a first period including a switching period for switching from a state where the analog audio signal is selected to a state where the digital audio signal is selected.

A radio signal processing circuit comprises multiple audio blend channels, an audio decoder, a program selector and a blending circuit. The audio blend channels are configured to receive digital audio packets for multiple supplemental audio programs. Each audio blend channel includes an audio blend buffer and a signal quality metric circuit. The signal quality metric (SQM) circuit configured to determines an audio quality indicator for the digital audio packets of the program and indicates availability of the program according to the audio quality indicator regardless of whether the program is selected for play. The program selector configured to provides digital audio packets from a selected audio blend channel to the audio decoder to produce a digital audio signal. The blending circuit blends the digital audio signal produced for the selected audio blend channel with a signal representing silence according to the audio quality indicator for the audio blend channel.

The present disclosure relates to a method and system for receiving a broadcast signal. The system includes a broadcast receiver device having two receiving units, two decoding units, a combining unit and a further processing unit. A broadcast signal is received by both receiving units, so that two reception signals are provided. From each reception signal, a raw data stream is extracted and decoded by the decoding units. It is checked if the data stream provided by each decoding unit is complete. If a first data stream is complete, it is processed by the further processing unit. If the first data stream is incomplete and the second data stream is complete, the second data stream is further processed. If both data streams are incomplete, they will be combined to a combined data stream by the combining unit, the combined data stream being further processed, if it is complete.

A radio signal processing circuit comprises multiple audio blend channels, an audio decoder, a program selector and a blending circuit. The audio blend channels are configured to receive digital audio packets for multiple supplemental audio programs. Each audio blend channel includes an audio blend buffer and a signal quality metric circuit. The signal quality metric (SQM) circuit configured to determines an audio quality indicator for the digital audio packets of the program and indicates availability of the program according to the audio quality indicator regardless of whether the program is selected for play. The program selector configured to provides digital audio packets from a selected audio blend channel to the audio decoder to produce a digital audio signal. The blending circuit blends the digital audio signal produced for the selected audio blend channel with a signal representing silence according to the audio quality indicator for the audio blend channel.

Travel-related-information messages (TRIMS) are received from one or more information sources, and information included in the messages is separated into a first (e.g. TPEG) or second (e.g. TPEG+) group. A broadcast area to which the information included in the TRIMs is to be broadcast is determined. A further determination indicates that a subset of information assigned to the first group is to be reassigned to the second group. The subset of information is reassigned from the first group to the second group based on parameters associated with the broadcast area. The information included in the first group and the second group is delivered to one or more processing modules that generate a first TRIM reporting message using information included in the first group and a second TRIM reporting message using information included in the second group.