Performance improvement of AMBE 3600 bps vocoder with adaptive forward error correction

Abstract

In this work, we present an adaptive forward error correction method with two different forward error correction schemes for Advanced Multi-band Excitation 3600 bps vocoder that is mainly utilized in Digital Mobile Radios. Utilized forward error correction schemes are proposed to be selected based on signal-to-noise ratio figures by radio itself. Proposed adaptive forward error correction scheme provides better performance with a 4.41 dB coding gain than what advanced multi-band excitation codec forward error correction provides if signal-to-noise ratio is above 3.25 dB. If the signal-to-noise ratio is not greater than 3.25 dB, the performance is the same as advanced multi-band excitation codec forward error correction.