ADSP 01 EC623 ADSP - Lecture notes 1 PDF

Preview

Summary

DSP...

Description

S. R. M. Prasanna Dept of ECE, IIT Guwahati, [email protected]

EC623: Advanced Topics in DSP (ADSP) – p. 1/1

Broad Topics Multirate Signal Processing (MSP) Time Frequency Analysis (TFA) Audio Coding (AC): Application of MSP & TFA Theory Lectures MSP: 14 TFA: 14 AC: 14 Total: 42

EC623: Advanced Topics in DSP (ADSP) – p. 2/1

Laboratory MSP: 03 TFA: 03 AC: 03 Total: 09 Written Assignments MSP: 02 TFA: 02 AC: 02 Total: 06

EC623: Advanced Topics in DSP (ADSP) – p. 3/1

Time-Table 3 Lectures / week 1 L for MSP (Tuesday, 9-10) 1 L for TFA (Wednesday, 9-10) 1 L for AC (Friday, 12-13) Lab: Wednesday, 15-17 Evaluation Quiz: 20 Marks (10%) (End of Jan) Mid-Sem: 40 Marks (25%) (End of Feb) End-Sem: 60 Marks (40%) (End of Apr) Laboratory & Assignments: Continuous (25%) Total: 100%

EC623: Advanced Topics in DSP (ADSP) – p. 4/1

Relation among different subjects Signals & Systems is the foundation part of signal processing area DSP is the central part of signal processing area ADSP is the peripheral part of signal processing area

EC623: Advanced Topics in DSP (ADSP) – p. 5/1

Classification of signals Properties of systems LTI System Correlation & Convolution Differential / Difference equation representation Fourier representation: CTFS, CTFT, DTFS and DTFT LT & ZT Concepts of impulse response, frequency response, system function & transfer function

EC623: Advanced Topics in DSP (ADSP) – p. 6/1

Sampling theorem: time and frequency domains DFT and its properties Circular shift and convolution FFT methods for DFT computation Analysis and design of IIR and FIR filters Structures for realization of filters Finite word length effects

EC623: Advanced Topics in DSP (ADSP) – p. 7/1

Any advanced topic on DSP Multirate DSP Time-frequency analysis Statistical signal processing Architecture of DSP processors Speech, Audio, Image and Video processing Biomedical signal processing Signal processing for communication

EC623: Advanced Topics in DSP (ADSP) – p. 8/1

Multirate DSP (MSP) Time-frequency analysis (TFA) Audio coding (AC): Applications of MSP & TFA

EC623: Advanced Topics in DSP (ADSP) – p. 9/1

Introduction and Applications of MSP. Decimation, Interpolation and Fractional Rate. Polyphase Representation for MSP. Introduction to Filter Banks. Maximally Decimated Filter Banks. Two QMF and M Channel Filter Banks. Polyphase Representation of Filter Banks. Perfect Reconstruction (PR) and Paraunitary PR. Two and M Channel Paraunitary Filter Banks. Linear Phase PR QMF Banks. Cosine Modulated Filter Banks and Pseudo QMF Bank. Recent trends in the Design of Filter Banks. EC623: Advanced Topics in DSP (ADSP) – p. 10/1

Introduction and Applications of TFA. Time and Frequency Description of Signals. Instantaneous Frequency and the Complex Signal. The Uncertainty Principle. Densities and Characteristic Functions. Time-Frequency Distributions: Fundamental Ideas. TFA using STFT and Wavelets. Wigner and Wigner-Ville Distribution. General and Kernel Method for designing TFDs. TFDs based on Kernel Methods. Comparison of Various TFDs. Recent Trends in TFA. EC623: Advanced Topics in DSP (ADSP) – p. 11/1

Introduction to Audio Coding. Psychoacoustic Principles for Audio Coding. Filter Banks for Audio Coding. Transform Coders for Audio Coding. Subband Coders for Audio Coding. Sinusoidal Coders for Audio Coding. Audio Coding Standards and Algorithms. Lossless Audio Coding. Quality Measures for Perceptual Audio Coding. Recent Trends in Audio Coding.

EC623: Advanced Topics in DSP (ADSP) – p. 12/1

P. P. Vaidyanathan, "Multirate systems and filter banks", Pearson, Delhi, 2004. L. Cohen, "Time-Frequency analysis", Prentice hall, NJ, USA, 1995. B. Boashash, "Time-frequency signal analysis and processing" Elsivier, 2003. A. Spanias, et. al., "Audio signal processing and coding", Wiley-Interscience, NJ, USA, 2007.

EC623: Advanced Topics in DSP (ADSP) – p. 13/1

Unirate: Processing of signals at one sampling rate. Multirate: Processing at multiple sampling rates. Merits of Multirate DSP. Reduced complexity & distortion. All digital implementation. No distortion due to ADC & DAC. Sampling rate conversion. Reduced transmission rate / storage requirement. On an average reduced number of bits / sample. Subband coding.

EC623: Advanced Topics in DSP (ADSP) – p. 14/1

Theory of filter banks and their application. Signal compression: subband coding. All digital sampling rate conversion.

EC623: Advanced Topics in DSP (ADSP) – p. 15/1

Time Domain Analysis: Amplitude v/s time Localization in time domain Good resolution in time domain Poor resolution in frequency domain Frequency Domain Analysis: Amplitude v/s frequency Localization in frequency domain Good resolution in frequency domain Poor resolution in time domain

EC623: Advanced Topics in DSP (ADSP) – p. 16/1

Time-Frequency Analysis: Amplitude v/s time and frequency. Localization in time and frequency domains. Ideally good resolution in both the domains. Simultaneous good resolution is not possible. Good resolution in one domain with a compromise on resolution in other domain.

EC623: Advanced Topics in DSP (ADSP) – p. 17/1

Short Term Fourier Transform (STFT). Wavelets. Time-frequency distributions (TFDs).

EC623: Advanced Topics in DSP (ADSP) – p. 18/1

Audio: Signals in AF (20 Hz - 20 kHz) range. Speech and music signals. Speech: 20 Hz - 8 kHz with max energy up to 4 kHz. Music: 20 Hz - 20 kHz. Audio processing: Mainly processing music signals. Audio coding: Different audio compression methods. Finds immense application in entertainment industry. MSP and TFA concepts are being extensively used in audio coding methods.

EC623: Advanced Topics in DSP (ADSP) – p. 19/1...