A simple interworking algorithm between fast power control and link adaptation for AMR
Original Publication Date: 2004-Jan-25
Included in the Prior Art Database: 2004-Jan-25
Related PeopleOther Related People:
With the introduction of AMR (Adaptive Multirate) in TSM dynamic switching between the AMR speech codecs will be possible. The goal is to improve the speech quality, as the user perceives it and, at the same time, keep the interference among users low. The codecs are selected according to the link quality. The worse the link, the more the codec should focus on the most important speech information and thus leave more room for channel protection. Fast power control strives to achieve a similar goal. The power is adjusted so that the signal-to-interference ratio (SIR) is maintained at a level where the speech quality is good and interference is as low as possible. Fast power control has been introduced with the beginnings of 3rd generation cellular systems. AMR will follow as a next step. In this document we describe an interworking algorithm between AMR and fast power control that harmonizes the two mechanisms. In order to judge the link quality we need a codec independent quality concept. In this document we assume that the GSM quality concept based on mean opinion scores has been transferred to TSM either by the method described in  or through own hearing experiments. Thus, for each codec, there is a curve describing the relation between signal-power-to-interference ratio (CI/ or equivalently SIR) and the mean opinion score MOS.