Non-intrusive speech quality estimation for GSM system using narrowband and wideband AMR codec

In a mobile communication system, it is important to assess the speech quality offered to the user. In GSM, if the AMR codec is employed, the vocoder bit-rate can be changed during a call according to the channel conditions. Speech quality evaluation can be difficult in this adaptive-rate scenario, and commonly used statistics, such as RXQUAL, are not sufficient for that purpose. This paper proposes a method for speech quality evaluation in GSM system employing AMR codec. Our method shows a very high correlation with ITU-PESQ for both narrowband and wideband AMR codecs.