Bad Parameter Indication for Error Concealment in Wireless Multimedia Communication

Wireless communication of multimedia signals is often based on the transmission of source codec parameters which are protected against channel noise by channel coding. Commonly, a cyclic redundancy check (CRC) is introduced in order to check for erroneous frames after error correction. If the CRC fails, a bad frame indication (BFI) flag is set which controls a codec-specific frame error concealment. This results in the substitution of complete multimedia frames by their concealed versions even if only a few parameters may be corrupted. The proposed system is based on iterative source-channel decoding. A low complexity bad parameter indication (BPI) scheme is introduced which identifies faulty decoded parameters and enables more effective parameter-individual concealment strategies. This concept may be applied to any multimedia codec (speech, audio, video, images).