Abstract: Systems and methods are disclosed for communicating an emergency alert message from a digital radio broadcast transmission system of a mobile vehicle to a digital radio broadcast receiver system. A digital radio broadcast signal including first and second data is broadcasted using the digital radio broadcast transmission system to end-user digital radio broadcast receivers. The first data includes an emergency code, and the second data includes an emergency alert message. The digital radio broadcast signal is transmitted at a predetermined frequency that is recognized by the receivers as an emergency notification frequency. The digital radio broadcast signal can be decoded only be receivers located within a localized area in a proximity of the transmission system. The receivers are configured to automatically tune to the emergency notification frequency to receive the digital radio broadcast signal and render the second data based on a detection of the emergency code within the signal.

Abstract: Systems and methods are disclosed for communicating an emergency alert message from a digital radio broadcast transmission system of a mobile vehicle to a digital radio broadcast receiver system. A digital radio broadcast signal including first and second data is broadcasted using the digital radio broadcast transmission system to end-user digital radio broadcast receivers. The first data includes an emergency code, and the second data includes an emergency alert message. The digital radio broadcast signal is transmitted at a predetermined frequency that is recognized by the receivers as an emergency notification frequency. The digital radio broadcast signal can be decoded only be receivers located within a localized area in a proximity of the transmission system. The receivers are configured to automatically tune to the emergency notification frequency to receive the digital radio broadcast signal and render the second data based on a detection of the emergency code within the signal.

Abstract: A translator includes: an input configured to receive a bit stream having a plurality of digitally encoded contents and control information; processing circuitry configured to select one of the digitally encoded contents, to use the selected digitally encoded content to produce an analog modulated signal, to use the digitally encoded contents to produce a digitally modulated signal, and to combine the analog modulated signal and the digitally modulated signal to produce a hybrid signal; and an output configured to output the hybrid signal. A method performed by the radio signal translator is also provided.

Abstract: A translator includes: an input configured to receive a bit stream having a plurality of digitally encoded contents and control information; processing circuitry configured to select one of the digitally encoded contents, to use the selected digitally encoded content to produce an analog modulated signal, to use the digitally encoded contents to produce a digitally modulated signal, and to combine the analog modulated signal and the digitally modulated signal to produce a hybrid signal; and an output configured to output the hybrid signal. A method performed by the radio signal translator 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 processing a radio signal which may include a narrowband signal or a wideband signal or both, comprises the steps of receiving the radio signal, initially processing the radio signal using a narrowband filter, switching to a wideband filter for further processing of the radio signal, determining if the wideband signal is acquired, and if the wideband signal is not acquired, alternating between narrowband filter processing for a narrowband filter hold time and wideband filter processing for a wideband filter hold time, where the narrowband filter hold time is gradually increased until a predetermined maximum time limit is reached. If the wideband signal is acquired, the narrowband filter hold time can be set to a predetermined minimum time limit. Receivers which implement the method are also provided.

Abstract: A method for processing a radio signal which may include a narrowband signal or a wideband signal or both, comprises the steps of receiving the radio signal, initially processing the radio signal using a narrowband filter, switching to a wideband filter for further processing of the radio signal, determining if the wideband signal is acquired, and if the wideband signal is not acquired, alternating between narrowband filter processing for a narrowband filter hold time and wideband filter processing for a wideband filter hold time, where the narrowband filter hold time is gradually increased until a predetermined maximum time limit is reached. If the wideband signal is acquired, the narrowband filter hold time can be set to a predetermined minimum time limit. Receivers which implement the method are 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 digital audio broadcasting comprises the steps of providing a plurality of bits of digital information to be transmitted, interleaving the bits of digital information into a plurality of partitions, 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 partitions include a main partition, a backup partition, an upper partition, and a lower partition, wherein the upper partition and lower partition are non-overlapping. The main partition overlaps both of the upper and lower partitions and the backup partition overlaps both of the upper and lower partitions. The interleaved bits comprise a core interleaver and an enhancement interleaver.