Parameter-based speech quality measures for GSM

This contribution introduces instrumental speech quality measures for the GSM system based only on transmission parameters. Certain combinations of GSM parameters which quantify the transmission quality in terms of bit error rate, received power level, etc., were shown be suitable for the prediction of the resulting speech quality. Neither the original nor the received speech signal is needed for this kind of prediction. The proposed speech quality measures have been validated by extensive link-level simulations which are based on measurements of transmission parameters collected in a GSM-1800 network. Speech samples were produced by bit-exact transmission simulations using the measured link parameters for channel modelling. The reference speech quality assessments of these samples were carried out with the PESQ algorithm Ref.3. The correlation of the presented parameter measures with the intrusive PESQ measure is remarkable.