A method and system for the transmission of digital data (210) over existing analog radio frequencies (230) is presented, wherein the digital data may include audio data, visual data or audio-visual data for presentation either with analog broadcast data or at a selectable time. The digital data may be transmitted over a plurality of sub-channels that have varying degrees or reliability (250). A quality-of-service process manages the transmission of digital data over various sub-channels based on the reliability of the sub-channel, the amount of digital data and the type of digital data to be transmitted. The digital data may further be encrypted and authenticated.

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).

A system comprises an Internet network interface, and a first server. The first server include a first port operatively coupled to the Internet network interface, a memory, a processor, and a service application for execution by the processor. The service application is configured to receive a digital audio file and associated radio broadcast information via the Internet network interface, obtain an audio file identifier using a segment of the digital audio file, forward the digital audio file to a radio broadcast system according to the radio broadcast information, receive the segment of the digital audio file and associated radio reception information via the internet network interface, and identify the digital audio file and record the radio reception information for the identified digital audio file.

A system comprises an Internet network interface, and a first server. The first server include a first port operatively coupled to the Internet network interface, a memory, a processor, and a service application for execution by the processor. The service application is configured to receive a digital audio file and associated radio broadcast information via the Internet network interface, obtain an audio file identifier using a segment of the digital audio file, forward the digital audio file to a radio broadcast system according to the radio broadcast information, receive the segment of the digital audio file and associated radio reception information via the internet network interface, and identify the digital audio file and record the radio reception information for the identified digital audio file.

A system comprises an Internet network interface, and a first server. The first server include a first port operatively coupled to the Internet network interface, a memory, a processor, and a service application for execution by the processor. The service application is configured to receive a digital audio file and associated radio broadcast information via the Internet network interface, obtain an audio file identifier using a segment of the digital audio file, forward the digital audio file to a radio broadcast system according to the radio broadcast information, receive the segment of the digital audio file and associated radio reception information via the internet network interface, and identify the digital audio file and record the radio reception information for the identified digital audio file.

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 communications device includes aspects for improving reception of transmissions with first-adjacent co-channel interference signals corresponding to digitally-modulated side-bands of in-band on-channel (IBOC) broadcasted signals. The communications device may include a radio frequency (RF) signal-reception circuit including two RF-signal paths driven in response to signals received via at least two respective antennas, and configured to respond to signals carried in the respective RF-signal paths by providing pre-processed RF output signals. The communications device may further include a beam-forming circuit driven in response to signals received at the at least two respective antennas and configured and arranged to facilitate first-adjacent interference cancellation (FAC). The communications device can also include an interference-cancelling circuit configured and arranged to reduce the first-adjacent co-channel interference signals by combining a beam-forming output signal provided by the beam-forming circuit with the pre-processed RF output signals as part of a maximum ratio combining (MRC) process.

An audio processor includes a detector configured to determine a correlation of first and second data corresponding to an analog FM component and an HD FM component, respectively, of a broadcast RF signal. A signal processor is configured to receive an input audio signal, to generate an analog FM audio signal and an HD FM audio signal therefrom and to control a relative timing of the analog FM audio signal and the HD FM audio signal based on the determined correlation. The signal processor may include a multiband limiter configured to generate a multiband limited audio signal responsive to the input audio signal, an HD FM audio processor configured to generate the HD FM audio signal responsive to the multiband limited audio signal, and an analog FM audio processor configured to generate the analog FM audio signal responsive to the multiband limited audio signal and to delay the analog FM audio signal responsive to the timing control signal.

A system for peak-to-average-power ratio (PAPR) reduction of a frequency shifted plurality of digital broadcast signals taking into account the combined signal peaks in order to transmit the signals more efficiently in a single broadcast transmission system. The PAPR algorithm takes into account a rotating constellation phase offset for the shifted signals corresponding to the amount of applied frequency shift. In the case of a dual sideband In-Band-On-Channel (IBOC) signal typically used in conjunction with an FM carrier in the center, the sidebands can be interleaved to create a new IBOC signal definition and take the place of the FM carrier for an all-digital transmission that is backward compatible with IBOC receivers allowing for a gradual migration to all digital broadcasting.

A communications device includes aspects for improving reception of transmissions with first-adjacent co-channel interference signals corresponding to digitally-modulated side-bands of in-band on-channel (IBOC) broadcasted signals. The communications device may include a radio frequency (RF) signal-reception circuit including two RF-signal paths driven in response to signals received via at least two respective antennas, and configured to respond to signals carried in the respective RF-signal paths by providing pre-processed RF output signals. The communications device may further include a beam-forming circuit driven in response to signals received at the at least two respective antennas and configured and arranged to facilitate first-adjacent interference cancellation (FAC). The communications device can also include an interference-cancelling circuit configured and arranged to reduce the first-adjacent co-channel interference signals by combining a beam-forming output signal provided by the beam-forming circuit with the pre-processed RF output signals as part of a maximum ratio combining (MRC) process.