Research And Development Of AMR Speech Coder In The 3rd Generation Mobile Communication System

AMR speech coder is a new speech coder recommendation produced by 3 GPP using on the 3rd generation mobile communication system W-CDMA.This paper mainly deal with the algorithms of AMR speech coder. On the basis of the study on the speech coder algorithms,paper describe an advanced method of developing DSP system software,and as the guidlines ,we developed the programme of whole decoder unit.Paper stress on analysis of the ECU in decoder unit.Aiming at AMR algorithms disadvantage of angularity of synthetical speech, Paper study on the specutral extrapolation which apply to extrapolate reflect coefficient of track model to make error conceal processing of AMR.At last paper analyze existing echo cancellation algorithms using on mobile communication system. According to different algorithms and different parameters .Paper analyze the efficiency of algorithms , and simulate the echo cancellation result.