REAL-TIME IMPLEMENTATION OF 16KB/S LOW-DELAY CELP SPEECH CODING ALGORITHM ON A TMS320C30

摘要

The 16kb/s LD-CELP speech coding algorithm is submitted by AT&T to CCITT for 16kb/s speech coding standard which can be used in many applications.After having investigated the algorithm carefully and simulated it in FORTRAN Language and DSP TMS320C30 assembly language respectively, We find that the difficulty to implement the 16kb/s LD-CELP algorithm on a TMS320C30 is its large computational loads and rather uneven distribution among 8 vectors in the same adaptation cycle. Some techniques are used in our program to reduce the computational loads and a recursive window is used to compute autocorrelation functions. At last, we employ about 90% processor time of a TMS320C30 to implement the 16kb/s LD-CELP coding algorithm in real-time.