mixed excitation linear predictive (Tetra) (MELP)

Mixed Excitation Linear Predictive (MELP) is a speech codec for voice compression. It was selected by the Department of Defense( DoD) and is used in US military applications and is a standard vocoder in NATO applications.

Since Terrestrial Trunked Radio( TETRA) can also be used for military services, the TETRA Technical Commission( TC) also selected MELP. MELP is optimized for speech compression and still delivers good speech intelligibility at the lowest data rates of 600 bit/s, 1.2 kbit/s, and 2.4 kbit/s. In addition, the MELP-Coced suppresses background noise and requires little power.

The MELP vocoder is available in different versions as Enhanced Mixed-Excitation Linear Predictive (MELPe) and also as MELPe++. The Enhanced versions have the disadvantage compared to the basic version that they increase the speech delay.