Viterbi algorithmIt is a dynamic programming algorithm used to find the most likely Viterbi path - a sequence of hidden states - that produces a sequence of observed events, especially in the context of Markov information sources and hidden Markov models. For example, in statistical syntactic analysis, dynamic programming algorithms can be used to find the most likely context-derived string, which is also called "Viterbi analysis".

The Viterbi algorithm was proposed by Andrew Viterbi in 1967 and is mainly used for deconvolution in digital communication links to eliminate noise. This algorithm is widely used in CDMA and GSM digital cellular networks, modems, satellites, deep space communications, and 802.11 wireless networks, mainly for deconvolution codes. It is now also commonly used in speech recognition, keyword recognition, computational linguistics, and bioinformatics.

In speech recognition, the sound signal can be regarded as an observed time series, and the text string can be regarded as an implicit cause. Therefore, the Viterbi algorithm can be used based on the sound signal to find the most likely text string.