Speech Codec

The speech codec is a proprietary unknown AMBE variant from ​DVSI.

Patents

The ETSI lists patents relevant to GMR. (See ​here). It is unknown if the list is complete and/or accurate though.

• ​US5226084 : Methods for speech quantization and error correction
• ​US5715365 : Estimation of excitation parameters
• ​US5826222 : Estimation of excitation parameters
• ​US5754974 : Spectral magnitude representation for multi-band excitation speech coders
• ​US5701390 : Synthesis of MBE-based coded speech using regenerated phase information