## 4.3.3 Channel SNR Estimator

06.943GPPTSVoice Activity Detector (VAD) for Adaptive Multi Rate (AMR) speech traffic channels

Estimate the channel SNR vector { } as:

(4.6)

where En(m) is the current channel noise energy estimate (see Section 4.3.8), and then quantify the channel SNR estimate in 3/8 dB steps to yield the channel SNR indices { q } given as:

(4.7)

where the values of { q } are constrained to be between 0 and 89, inclusive.