摘要 |
A bit adding part acquires RSSI as measured by an RSSI measuring part, and adds “1” to each bit of protected audio data of an audio vocoder, if the acquired RSSI is smaller than a predetermined threshold value. If the acquired RSSI is equal to or greater than the predetermined threshold value, the bit adding part adds the bits of additional data to the respective bits of the protected data of the audio vocoder. A frame recovery part separates upper and lower order bits of deinterleaved data, and determines, based on CRC, whether eight data parts as obtained by combining the lower order bits as separated are valid. If so, the frame recovery part combines the eight data parts as the additional data to recovery additional information. In this way, additional data can be efficiently transmitted, while error correction being performed in accordance with communication environment.
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