METHOD FOR CORRECTING FRAME ERROR ON VOCODER BYPASS MODE OF DIGITAL MOBILE COMMUNICATION SYSTEM

摘要

PURPOSE: An error frame recovery method in vocoder bypass mode of digital mobile communication system is provided to correct an error frame using vocoding algorithm so as to improve quality and efficiency. CONSTITUTION: A transfer mode of packet data from a terminal through parallel interface is determined. If the transfer mode is set as a vocoding mode, the input packet data is transferred after decoding. If the transfer mode is set as a bypass mode, the input packet data is checked to verify whether the input packet data has any error frames. If the input packet doesn't have any error frames, bypass is executed, and if the input packet has error frames, the input packet data is decoded. The result of bypass execution and the result of the input packet data decoding are stored in orderly manner and merged. A flag indicating PCM(Pulse Code Modulation) in bypass mode is set, and use chosen bytes that are not continuous and use as preamble in the storage step of bypass serial interface buffer.