AN OPTIMAL INTEGER ALLOCATION SCHEME FOR SUB-BAND CODING OF SPEECH

Abstract

An optimal integer allocation algorithm for block quantization is introduced, which can be applied to Sub-Band Coding of Speech. The new scheme, which is a generalization of the various commonly used bit allocation (radix 2) schemes, improves current block quantization techniques in three aspects: • Any integer number of quantization levels, rather than only radix 2 integers, can be assigned to the different blocks. • The assigned levels are determined optimally using an efficient dynamic programming algorithm. • The proposed algorithm can be used to generate optimal power of 2 integer levels as well, in contrast to some heuristic, sub-optimal algorithms which have been previously employed in bit allocation schemes. This result in a better allocation of the bits resource to the different channels according to their respective energy. Thus, the total quantization noise is reduced and the quality of the reconstructed signal may improve appreciably.