| DSP for In-Vehicle and Mobile Systems is focused on digital signal processing strategies for improving information access, command and control, and communications for in-vehicle environments. It is expected that the next generation of human-to-vehicle interfaces will incorporate speech, video/image, and wireless communication modalities to provide more comfortable and safer driving ambiance. It is also expected that vehicles will become
While this outstanding book is a major contribution to our scientific literature, it represents but a small chapter in the anthology of technical contributions made by Professor Itakura. His purview has been broad. But always at the center has been digital signal theory, computational techniques, and human communication. In his early work, as a research scientist at the NTT Corporation, Itakura brought new thinking to bit-rate compression of speech signals. In partnership with Dr. S. Saito, he galvanized the attendees of the 1968 International Congress on Acoustics in Tokyo with his presentation of the Maximum Likelihood Method applied to analysis-synthesis telephony. The presentation included demonstration of speech transmission at 5400 bits/sec with quality higher than heretofore achieved. His concept of an allpole recursive digital filter whose coefficients are constantly adapted to predict and match the short-time power spectrum of the speech signal caused many colleagues to hurry back to their labs and explore this new direction. From Itakura’s stimulation flowed much new research that led to significant advances in linear prediction, the application of autocorrelation, and eventually useful links between cepstral coefficients and linear prediction. Itakura was active all along this route, contributing among other ideas, new knowledge about the Line Spectral Pair (LSP) as a robust means for encoding predictor coefficients. A valuable by-product of his notion of adaptively matching the power spectrum with an all-pole digital filter gave rise to the Itakura-Saito distance measure, later employed in speech recognition as well as a criterion for low-bit-rate coding, and also used extensively in evaluating speech enhancement algorithms. |
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