Optimizations of ITU G.729 speech codec

Modern mobile communications require optimum bandwidth utilization with minimum loss, delay and good quality of speech transmission. This triggered the usage of low bit rate voice codecs, among which CELP codecs inherit the merits of both waveform and source codecs, like toll quality, low bit rate etc. In this paper several hardware and software optimization techniques are presented for efficient implementation of ITU G.729 standard (CS-ACELP, conjugate structure algebraic code excited linear prediction) of 8 Kbit/s bit rate on a real time digital signal processor (DSP), with the aim of overcoming the limitation of computational burden and also scaling this application for enhanced speed to process more channels. These techniques are in general applicable to any speech codec and DSP processor platform.