A novel efficient decoding algorithm for CDHMM-based speech recognizer on chip

The efficiency of decoding algorithm is the main limitation of realizing a CDHMM-based large-vocabulary name dialing application on consumer electronic products. To solve this problem, a novel efficient decoding algorithm, TPVD (two-pass Viterbi decoding), is represented. By coarse matching in the first pass, several high-confidence candidates are selected from hundreds. Then, fine matching in the second pass runs on base of those high-confidence candidates. Compared with traditional Viterbi beam search, the hardware resource requirement is significantly reduced. Meanwhile, the recognition accuracy and speed are satisfactory. This conclusion has been proven in an embedded Mandarin 600-name dialing system.