Multi-Band Excitation

Advanced Multi - Band Excitation ( AMBE ) is a proprietary and patent -protected speech codec and registered trademark of Digital Voice Systems, Inc. for very low bit rate areas 2000-9600 bit / s

Features

Its capacity exceeds the same data rate of MELP (although AMBE aimed at a slightly increased data rate range ). AMBE simultaneously has a low level of complexity - less than that of the CELP method.

The audio data can be combined with forward error correction data for up to 7,200 bit / s. Nevertheless occurring block losses can be masked by the parameters of the previous block are used to fill the gap.

The design of the AMBE - codebooks provides certain ( sturgeon) to reject noise is not of human origin such as AC hum, wind noise and similar radical. The implementation in DVSI 's AMBE 2020 chip provides voice activity detection and comfort noise.

Since there are with such low data rates, can it - even though it is digital signals - such as with single sideband ( SSB) modulated voice signals communicated over narrowband channels.

Technology

AMBE uses codebooks at a sampling rate of 8 kHz, into 20 ms blocks.

History

DVSI improved the Multi- Band Excitation ( MBE ) technology at the Massachusetts Institute of Technology (MIT) from 1980, which is used in many communication systems worldwide. The Improved Multi- Band Excitation ( IMBE ) speech codec was the resulting product. AMBE represents the further improved successor

Examples of use

He is in satellite telephone systems (eg Inmarsat, Iridium, ACeS and Optus ) systems, on certain ( voice ) channels in XM Satellite Radio, the transmission standard D- STAR and the amateur radio protocol by Charles Brain (call sign G4GUO ) on the shortwave used and the speech codec is at OpenSky trunked radio systems.

In Digital Mobile Radio ( DMR ) AMBE is an option for voice data. At APCO P25 AMBE is introduced with equipment of Phase 2.