Access to wireless data services such as e-mail, news, stock quotes, flight schedules, weather forecasts, etc. is already a reality for cellular phone and pager users. However, the user interface of these services leaves much to be desired. Users still have to navigate menus with scroll buttons or ‘‘type in’’ information using a small keypad. Further, users have to put up with small, hard-to-read phone/pager displays to get the results of their information access. Not only is this inconvenient, but also can be downright hazardous if one has to take their eyes off the road while driving | The Application of Programmable DSPs in Mobile Communications Edited by Alan Gatherer and Edgar Auslander Copyright 2002 John Wiley Sons Ltd ISBNs 0-471-48643-4 Hardback 0-470-84590-2 Electronic 10 Speech Recognition Solutions for Wireless Devices Yeshwant Muthusamy Yu-Hung Kao and Yifan Gong Introduction Access to wireless data services such as e-mail news stock quotes flight schedules weather forecasts etc. is already a reality for cellular phone and pager users. However the user interface of these services leaves much to be desired. Users still have to navigate menus with scroll buttons or type in information using a small keypad. Further users have to put up with small hard-to-read phone pager displays to get the results of their information access. Not only is this inconvenient but also can be downright hazardous if one has to take their eyes off the road while driving. As far as input goes speaking the information . menu choices company names or flight numbers is a hands-free and eyes-free operation and would be much more convenient especially if the user is driving. Similarly listening to the information spoken back is a much better option than having to read it. In other words speech is a much safer and natural input output modality for interacting with wireless phones or other handheld devices. For the past few years Texas Instruments has been focusing on the development of DSP based speech recognition solutions designed for the wireless platform. In this chapter we describe our DSP based speech recognition technology and highlight the important features of some of our speech-enabled system prototypes developed specifically for wireless phones and other handheld devices. DSP Based Speech Recognition Technology Continuous speech recognition is a resource-intensive algorithm. For example commercial dictation software requires more than 100 MB of disk space for installation and 32 MB for execution. A typical embedded system however has .
