The present invention provides a system for frequency modulation of high definition composite video broadcast signals in a wireless transmission environment and a method thereof, comprising: a transmitting unit and a receiving unit. An image sensor of the transmitting unit converts an image to a digital signal. A signal processor converts the digital signal to a composite video broadcast signal. A frequency modulator modulates the composite video broadcast signal to a first modulated signal. The receiving unit receives the first modulated signal. A low noise amplifier converts the first modulated signal to a second modulated signal. A frequency demodulator restores the second modulated signal to the composite video broadcast signal. After an image decoder decodes the composite video broadcast signal, the image decoder outputs a digital signal in a specific format.

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.

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 method of processing a digital radio broadcast signal includes: (a) determining a plurality of current correlation sample values representative of a time delay between samples in an analog audio sample stream and samples in a digital audio sample stream; (b) determining a current inversion status; (c) updating a delay history and an inversion status history; (d) checking the current correlation sample values for consistency with a first confidence threshold; (e) if consistency is found in step (d), determining if each of a first plurality of values in the delay history is consistent within a predetermined range of the current correlation sample values; (f) if consistency is found in step (e), determining if a value in the inversion status history is consistent with the current inversion status; and (g) if the consistency is found in step (f), allowing blending of an output to the digital audio sample stream.

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.

A method of processing a digital radio broadcast signal includes: (a) determining a plurality of current correlation sample values representative of a time delay between samples in an analog audio sample stream and samples in a digital audio sample stream; (b) determining a current inversion status; (c) updating a delay history and an inversion status history; (d) checking the current correlation sample values for consistency with a first confidence threshold; (e) if consistency is found in step (d), determining if each of a first plurality of values in the delay history is consistent within a predetermined range of the current correlation sample values; (f) if consistency is found in step (e), determining if a value in the inversion status history is consistent with the current inversion status; and (g) if the consistency is found in step (f), allowing blending of an output to the digital audio sample stream.

The invention provides a reception method and apparatus which provides a series of frequency shifts and filtering operations to sideband signals (lower, upper, and middle), to enable detection if the central part of a signal is analog or digital, and to enable effective co-channel interference compensation. The invention enables (H)IBOC signals for example to be processed with a narrower bandwidth and therefore a lower processing clock speed and complexity is made possible compared to the conventional (H)IBOC-signal processing approach.

A broadcast system may have less restrictive timing constraints by providing synchronous processing chains for the HD audio portion and the FM audio portion so that no samples are added or removed from when the input audio is first sampled at an input rate and when the signals are combined and output by a digital analog converter operating at an output rate. The signals can be buffered within the synchronous processing paths and the state of the buffer can be used to control the input rate of the sampler. Graceful change over across multiple input sources can be achieved provided all input source input rates are controlled to by the overall output rate and all input sources are phase aligned to produce output symbols at the same time.