Performance comparison of source controlled GSM AMR and SMV vocoders
J. Makinon, P. Ojala, Henri Toukomaa · 2005
The adaptive multi-rate (AMR) speech codec offers substantial improvement over previous GSM speech codecs in error robustness by adapting speech and channel coding depending on channel conditions. In GSM AMR, the trade-off between speech quality and average bit rate can be further improved by source signal based rate adaptation (SBRA). Together with fast power control, SBRA GSM AMR can be used as a variable rate codec, bringing reduced average bit rate and contributing to an increase in system capacity. SBRA GSM AMR was tested against a currently standardised SMV (selectable mode vocoder) variable rate speech codec. The paper also presents the general descriptions of both SBRA GSM AMR and SMV codecs.