Bài giảng Xử lý tín hiệu số: Chương 1 - TS. Hà Hoàng Kha

Bài giảng "Xử lý tín hiệu số - Chapter 1: Sampling and reconstruction" gồm có những nội dung chính sau: Sampling theorem, spectrum of sampling signals, Antialiasing prefilter, analog reconstruction, . Mời các bạn cùng tham khảo. | Chapter p 1 Sampling and Reconstruction Ha Hoang Kha to edit Master subtitle style Ho Chi Minh City University of Technology @ Email hhkha@ https tailieudientucntt Content Sampling Sampling theorem Spectrum of sampling signals Antialiasing prefilter Ideal Id l prefilter fil Practical prefilter Analog reconstruction Ideal reconstructor Practical reconstructor Ha H. Kha 2 Sampling and Reconstruction https tailieudientucntt Review of useful equations x t Linear system y t x t h t Linear system h t X f H f Y f X f H f Especially x t A cos 2π f 0t θ Especially y t A H f 0 cos 2π f 0t θ arg H f 0 1 Fourier transform cos 2π f 0t δ f f 0 δ f f 0 FT 2 1 sin 2π f 0t FT j δ f f 0 δ f f 0 2 1 Trigonometric formulas cos a cos b cos a b cos a b 2 1 sin a sin b cos a b cos a b 2 1 sin a cos b sin a b sin a b 2 Ha H. Kha 3 Sampling and Reconstruction https tailieudientucntt 1. Introduction A typical signal processing system includes 3 stages The Th analog l signal i l is i digitalized di i li d b by an A D converter The digitalized samples are processed by a digital signal processor. The digital processor can be programmed to perform signal processing operations such as filtering spectrum estimation. Digital signal processor can be a general purpose computer DSP chip or other digital hardware. The resulting output samples are converted back into analog by a D A converter. Ha H. Kha 4 Sampling and Reconstruction https tailieudientucntt 2. Analog to digital conversion Analog to digital A D conversion is a three-step process. x t Sampler Quantizer xQ n Coder x nT x n 11010 t nT A D converter x t x n 111 xQ n 110 101 100 011 t n 010 n 001 000 Ha H. Kha 5 Sampling and Reconstruction https tailieudientucntt 3. Sampling Sampling is to convert a continuous time signal into a discrete time signal The analog signal is .