- This STANAG contains design requirements for analog-to-digital conversion of voice by 2,400 bit/s Enhanced Mixed Excitation Linear Prediction (MELPe). The design requirements are also included for an adaptation of MELPe for use at 1,200 bit/s. In addition, the STANAG contains the design requirements for a noise preprocessor that, used in conjunction with the MELPe coder will result in improved voice quality. MELPe is designed as an alternative for CELP. MELPe is robust in difficult background noise environments such as frequently encountered in commercial and military communication systems.