In this paper, we present a novel competitive learning algorithm for the de
sign of a variable-rate vector quantizer (VQ). The algorithm, termed entrop
y-constrained competitive learning (ECCL) algorithm, can achieve a near-opt
imal performance subject to the average rate constraint. Simulation results
show that, under the same average rate, the ECCL algorithm enjoys a better
performance than that of the existing competitive learning algorithms. Mor
eover, the ECCL algorithm outperforms the entropy-constrained vector quanti
zer (ECVQ) (Chou et al., IEEE Trans. Acoust. Speech Signal Process. 37 (198
9) 31-42) design algorithm under the same rate constraint and initial codew
ords. The ECCL algorithm is also more insensitive to the selection of initi
al codewords as compared with the ECVQ algorithm. Therefore, the ECCL algor
ithm can be an effective alternative to the existing variable-rate VQ desig
n algorithms for the applications of signal compression. (C) 1999 Elsevier
Science B.V. All rights reserved.