ASIC design of a phoneme recogniser based on discrete wavelet transforms and support vector machines

This paper presents the design of an ASIC for the task of multi-speaker phoneme recognition in continuous speech environments. The phoneme recogniser is based on DWTs for feature extraction and the One-against-one SVM method, along a priorities scheme, for classification. The ASIC design was fabricated on an AMS 0.35μ CMOS C35B4C3 chip. The final ASIC design resulted into a chip size equal to 43.35mm², with the requirement of an external memory storage of size 18.25Mb. Moreover, the ASIC design of the phoneme recogniser is approximately 4 times faster than the equivalent software-based approach and consumes 12.5mW, making it appealing to mobile devices. The performance results obtained from the ASIC design confirmed that this system is a promising basis for future hardware ASR systems.