Presentation on theme: "EC3400: Introduction to Digital Signal Processing"— Presentation transcript:
1 EC3400: Introduction to Digital Signal Processing byRoberto CristiProfessorDept. of ECENaval Postgraduate SchoolMonterey, CA 93943
2 Week 1 Topics:IntroductionFourier Transform (Review)SamplingReconstructionDigital FilteringExample: a Digital Notch Filter
3 IntroductionObjectives In this course we introduce techniques to process signals by digital computers.A signal can come from a number of different sources:filtered signal:reject disturbances.sonarDSPHardwareSoftwareradartransformed signal:detectioncompressionaudiovideo...
4 A Digital Filter ADC LPF DSP LPF LPF ADC DSP LPF antialiasing DACLPFLPFADCDSPDACLPFantialiasingreconstruction
5 We review the relations between the spectra of the signals in the following operations: Sampling:LPFDigital Filtering:DACLPFReconstruction:
6 Structure of a Digital Filter continuous timediscrete timecontinuous timeADCDACLPFZOHLPFanti-aliasingfilterreconstructionfilterclockProblem: determine the continuous time frequency response.
7 Recall: the Fourier Transform of a continuous time signal the Discrete Time Fourier Transform of a discrete time signal
8 Sampling of a continuous time signal: ADCmathematical model of the sampler: it appends a to each sample
9 We can write the same expression in two different ways: FTFTsincesince
15 Example: suppose we design a notch discrete time filter with transfer function with zeros and polesand sampling frequency Determine the magnitude of its frequency response in the continuous time domain.z-plane
16 Solution: from what we have seen the frequency response is given by