摘要 |
Techniques to support adaptive multi-rate (AMR) coded data in a cdma2000 communication system. A number of AMR modes are defined for speech information (of various rates), silence descriptor (SID) (of various types), and blank frame. The speech and SID data are provided in frames conforming to frame formats defined by the cdma2000 system. A CRC is used for each AMR frame (e.g., 12-bit CRC for speech and 8-bit CRC for SID). The AMR data and CRC bits are further coded with a conventional encoder. Blind rate detection is used to detect the frame rate of the transmitted AMR frames. To support blind rate detection, the number of bits provided to the CRC generator is different for each blind rate to be detected. If two or more blind rates have the same number of bits (such as for SID), then format bits are provided to distinguish between these rates.
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