标题: Digital signal processing [打印本页] 作者: Pang8343569 时间: 2016-11-3 14:13 标题: Digital signal processing Digital signal processing (DSP) refers to anything that can be done to a( J" R r Z; r/ `2 D! t& Z
signal using code on a computer or DSP chip. To reduce certain* H) A" R: R+ p' b2 z$ s8 [
sinusoidal frequency components in a signal in amplitude, digital filtering # M0 B g2 m+ b1 z0 f2 F0 X! H( Nis done. One may want to obtain the integral of a signal. If the signal$ f- h( g, v4 z+ p
comes from a tachometer, the integral gives the position. If the signal is8 G, L/ }3 G8 W- d ]+ `# U5 _
noisy, then filtering the signal to reduce the amplitudes of the noise 6 H2 ~' s b; `4 q5 \( J; y$ @frequencies improves signal quality. For example, noise may occur from 3 B; l V: u0 @/ A; O Zwind or rain at an outdoor music presentation. F iltering out sinusoidal 4 n, Y$ t2 k5 m Ncomponents of the signal that occur at frequencies that cannot be ! [5 x* H5 g( F7 Tproduced by the music itself results in recording the music with little wind) o* E$ p5 k0 D7 }# m
and rain noise. Sometimes the signal is corrupted not by noise, but by , D/ b6 t9 H" `# ?other signal frequencies that are of no present interest. If the signal is an6 ~, |! l( S1 v& {1 o
electronic measurement of a brain wave obtained by using probes applied 4 U+ ?2 f% e2 w& t( K: ~externally to the head, other electronic signals are picked up by the9 z" T/ A9 j9 |3 u+ a; @1 y
probes, but the physician may be interested only in signals occurring at a Y- P% L6 p" t7 J7 ^ A
particular frequency. By using digital filtering, the signals of interest only 4 H$ n/ G& [% r8 K0 T# _, dcan be presented to the physician.
