Low Delay Sparse and Mixed Excitation CELP Coders for Wideband Speech Coding

Low Delay Sparse and Mixed Excitation CELP Coders for Wideband Speech Coding

Blog Article

Code Excited Linear Prediction (CELP) algorithms are proposed for compression of speech in 8 kHz band at switched or variable bit rate and algorithmic delay not exceeding 2 msec.Two structures of Low-Delay CELP coders are analyzed: Low-delay sparse excitation and 15-eg1053cl mixed excitation CELP.Sparse excitation is based on MP-MLQ and multilayer models.Mixed excitation CELP algorithm stems grandpas best from the narrowband G.728 standard.

As opposed to G.728 LD-CELP coder, mixed excitation codebook consists of pseudorandom vectors and sequences obtained with Long-Term Prediction (LTP).Variable rate coding consists in maximizing vector dimension while keeping the required speech quality.Good speech quality (MOS=3.9 according to PESQ algorithm) is obtained at average bit rate 33.

5 kbit/sec.