USAC Audio Encoding for DAB+ Compatibility and Robustness

The patent implements dynamic switching between different audio coding methods (USAC/xHE-AAC and traditional AAC) based on system capabilities and transmission conditions. The encoding apparatus can adaptively select the appropriate coding standard, allowing high-quality audio when conditions permit while maintaining backward compatibility when dealing with legacy DAB+ receivers, thus resolving the contradiction between advanced audio quality and system compatibility

The patent modifies transmission parameters by introducing specific frame structures and syntax elements that indicate coding method usage. By changing parameters such as frame size, channel configuration indicators, and mode extension flags, the system can convey advanced USAC audio quality while providing compatibility information for existing DAB+ systems that may not support the full USAC feature set

The patent applies forward error correction (FEC) mechanisms and introduces redundancy in the audio frame structure before transmission. By pre-configuring error protection and using robust channel coding schemes, the system cushions against potential transmission errors that might occur with advanced USAC encoding, thus maintaining transmission robustness while benefiting from improved encoding efficiency

The patent introduces an intermediary layer between the USAC encoder and the transmission channel, implementing a hybrid encoding approach where certain critical audio data is encoded with higher redundancy and error protection. This intermediary protection mechanism ensures that even if transmission errors occur, the core audio quality is preserved, thereby maintaining robustness while utilizing efficient USAC encoding

The patent segments the audio encoding functionality into distinct modules: a core AAC encoding path and an extended USAC/xHE-AAC encoding path. The system includes separate encoding apparatus for each method, allowing independent operation and selection. This segmentation reduces complexity by enabling the system to activate only the necessary encoding module based on the target device capabilities, rather than maintaining full functionality of both methods simultaneously

The patent implements a universal audio encoding framework that can handle both AAC and USAC/xHE-AAC through a common interface and control structure. The encoding apparatus includes a unified parameter management system that adapts to the selected coding method, reducing overall system complexity while maintaining support for multiple coding standards. This multi-functional design allows a single apparatus to serve multiple purposes without requiring completely separate implementation paths