--- In [email protected], "n3hkn" <[EMAIL PROTECTED]> wrote: > > I do not understand the use of "decimation" in the context of DSP > software. The dictionary only refers to it as killing every tenth > person. ??????? > > Dick N3HKN
The dictionary is right. The term "decimation" has its roots in the practice of the ancient Romans to kill one prisoner out of every ten, when the prisoners had to be punished for whatever reasons...in Latin ten is "decem", hence the term. In DSP terminology, the term decimation refers to the method used when you want to downsample, in other terms when you want to reduce the sampling rate of a signal. What is done is simply to take one sample out of every N, where N is the decimation factor, or ratio. The other samples are simply discarded. The method works thanks to the Nyquist theorem, provided or course that before decimating you filter your signal so to avoid aliasing artifacts at the new, lower, sampling rate. 73 Alberto I2PHD ------------------------ Yahoo! Groups Sponsor --------------------~--> Check out the new improvements in Yahoo! Groups email. http://us.click.yahoo.com/6pRQfA/fOaOAA/yQLSAA/ELTolB/TM --------------------------------------------------------------------~-> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/soft_radio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
