A high‐speed dp‐matching algorithm based on frame synchronization, beam search and vector quantization

Abstract

AbstractThis paper discusses the high‐speed DP‐matching as the speech recognition algorithm including connected word sequence recognition. The first improvement is the frame synchronization. By this elaboration, an improvement of the speed by approximately one order of magnitude is achieved, compared with the consecutive word recognition of two‐level DP‐matching type, where DP‐matching is iterated by assuming that any time in the input speech can be the word boundary. The second improvement is the introduction of the beam search.This paper discusses the practical aspects of combining the beam search and DP‐matching. The discussion includes the construction of the work area, control of DP recursive expression and other problems, aiming at an effective reduction of the computational complexity for the recursive expression. The third improvement is the built‐in vector quantization. It is shown that an effective reduction of the computational complexity for the local distance can be produced through a skillful integration of the beam search and the vector quantization.Through an evaluation experiment for the discrete word, it is seen that there is a possibility of achieving the speed improvement by a factor of 30. This corresponds to the speed improvement of two or more orders of magnitude, compared with the two‐level DP‐matching for the consecutive word sequence recognition algorithm.