Digital Signal Processing
Discrete-time signals and systems, the z-transform, sampling, the DFT and FFT, and digital filter design -- built on Fourier Analysis and Probability, with every technique answering "what does this do to a real signal?"
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- Chapter overview
- What is a signal? Continuous-time vs. discrete-time ~12 min
- Complex numbers and Euler's formula in the j convention ~16 min
- Discrete-time signal notation: brackets, indices, and elementary sequences ~12 min
- Summation notation and the geometric series, revisited ~10 min
- Reading NumPy array conventions for signals ~10 min
- Random variables, expectation, and variance β what a random signal is made of ~16 min
1 Classifying signals and systems π
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- Deterministic vs. random, periodic vs. aperiodic signals ~12 min
- Energy signals and power signals ~12 min
- Even and odd signals, and the even/odd decomposition ~12 min
- Exponential and sinusoidal sequences ~12 min
- Sequence transformations: shifting and reflection ~12 min
- Sequence transformations: time-scaling and amplitude-scaling ~12 min
- System properties: memory, causality, and stability ~14 min
- Linearity and time-invariance -- why LTI systems are special ~14 min
- A DSP application survey ~10 min
2 Convolution and difference equations π
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- The convolution sum, derived from the sifting property ~14 min
- Graphical and analytical convolution evaluation ~14 min
- LTI system properties via convolution algebra ~12 min
- Numerical convolution: stream vs. block processing ~14 min
- Linear constant-coefficient difference equations ~14 min
- Recursive vs. non-recursive systems, and what that means for memory ~12 min
- Homogeneous and particular solutions ~14 min
- Zero-input and zero-state response ~12 min
- Real-time FIR implementation, a first look ~12 min
3 The Fourier representation of discrete-time signals π
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- The Fourier transform, its properties, and the convolution theorem, revisited ~12 min
- Discrete-time sinusoid periodicity, revisited for the frequency domain ~10 min
- The discrete-time Fourier transform (DTFT), defined ~14 min
- DTFT properties ~12 min
- Periodicity of the DTFT ~10 min
- The four Fourier representations, unified ~12 min
- Magnitude and phase spectra: reading a DTFT ~12 min
- Relating a system's frequency response to its difference equation ~12 min
4 Transform analysis of LTI systems π
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- Sinusoidal steady-state response ~12 min
- Frequency-domain response to general inputs ~10 min
- Magnitude and phase (group-delay) distortion ~12 min
- Ideal vs. practical filter types: tolerance diagrams ~12 min
- The z-transform: why a transform beyond the DTFT is needed ~10 min
- The z-transform: definition, region of convergence, and common pairs ~14 min
- The inverse z-transform ~14 min
- Z-transform properties ~12 min
- Poles, zeros, and the system function H(z) ~14 min
5 Poles, zeros, and system behavior π
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- Pole-zero geometry and time-domain behavior ~12 min
- The vector argument for frequency-response shape ~12 min
- A first filter design by direct pole-zero placement ~12 min
- Magnitude-phase relationships ~12 min
- Allpass systems ~12 min
- Minimum-phase systems and minimum-phase/allpass decomposition ~14 min
- Invertibility of LTI systems ~12 min
- Why pole-zero intuition is load-bearing for filter design ~10 min
6 Sampling and reconstruction π
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- Recall: the Nyquist-Shannon theorem and aliasing ~10 min
- The "impersonation" framing of aliasing ~10 min
- Ideal reconstruction and bandlimited (sinc) interpolation ~12 min
- Practical, non-ideal sampling and reconstruction ~12 min
- The sandwich model of continuous-signal processing ~10 min
- Bandpass sampling ~12 min
- Deliberately violating the Nyquist criterion ~10 min
- A first look at quantization ~8 min
- Two-dimensional sampling ~8 min
7 The Discrete Fourier Transform π
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- Recall: the DFT definition and circular convolution ~12 min
- Why only the DFT is exactly computable ~10 min
- The DFT as a sampled DTFT ~10 min
- Linear convolution via the DFT and zero-padding ~14 min
- Spectral leakage ~12 min
- Window functions and their trade-offs ~14 min
- The spectrogram of a synthesized signal ~12 min
- Fourier-based signal analysis, worked end to end ~12 min
8 The Fast Fourier Transform π
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- Direct DFT computation: an O(NΒ²) baseline ~10 min
- The FFT idea via matrix factorization ~14 min
- Decimation-in-time FFT and the butterfly diagram ~14 min
- Decimation-in-frequency FFT ~12 min
- Bit-reversal and in-place computation ~12 min
- O(N log N) versus O(NΒ²), measured ~10 min
- Other FFT families ~8 min
9 Structures for discrete-time systems π
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- Block diagrams and signal-flow graphs ~10 min
- Direct form I and direct form II ~12 min
- Cascade and parallel structures ~12 min
- FIR structures and the linear-phase folded form ~12 min
- Lattice structures and reflection coefficients ~14 min
- The lattice-coefficient stability test ~12 min
- Why structure choice matters: coefficient sensitivity ~10 min
10 Design of FIR filters π
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- The filter-design problem: five stages ~10 min
- Linear-phase FIR filters and the four symmetry types ~12 min
- The windowing method ~12 min
- The frequency-sampling method ~12 min
- Chebyshev polynomials and minimax approximation ~12 min
- The Paley-Wiener theorem ~12 min
- The alternation theorem and equiripple design ~14 min
- Special FIR filters: differentiators ~10 min
- Special FIR filters: Hilbert transformers ~10 min
11 Design of IIR filters π
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- The Butterworth analog prototype ~12 min
- The Chebyshev I analog prototype ~12 min
- Chebyshev II and elliptic prototypes ~10 min
- The three conditions for a valid transformation ~10 min
- The impulse-invariance transformation ~12 min
- The bilinear transformation ~12 min
- Frequency prewarping ~10 min
- Frequency transformations: lowpass to highpass, bandpass, bandstop ~12 min
- Choosing FIR vs. IIR ~10 min
12 Random signals π
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- Recall: random variables, joint distributions, and covariance ~10 min
- Why deterministic-signal tools don't apply to random signals ~10 min
- Stationarity of random processes ~10 min
- Wide-sense stationarity and ergodicity ~12 min
- The autocorrelation sequence ~12 min
- Power spectral density ~12 min
- White noise and AR/MA/ARMA process models ~12 min
- Linking process statistics to filter design ~10 min
13 Random signal processing π
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- Estimating statistics from data: bias, consistency, asymptotic unbiasedness ~12 min
- The periodogram: a poor PSD estimator ~12 min
- Bartlett and Welch averaging ~12 min
- The Wiener filter and the orthogonality principle ~14 min
- The matched filter and signal detection ~12 min
- Cross-correlation for time-delay estimation ~10 min
- Linear prediction and all-pole modeling ~14 min
- The Karhunen-Loève transform ~12 min
14 Multirate signal processing π
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- Decimation, downsampling, and anti-aliasing ~12 min
- Interpolation, upsampling, and anti-imaging ~12 min
- Rational-factor sample-rate conversion ~12 min
- Polyphase decomposition and the noble identities ~12 min
- Half-band filters and interpolated FIR (IFIR) design ~12 min
- Two-channel filter banks: quadrature mirror filters and perfect reconstruction ~14 min
- Why multirate design is a systems-engineering trade-off ~10 min
15 Finite wordlength effects π
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- Fixed-point, floating-point, and two's-complement number representation ~12 min
- The uniform quantization-noise model ~12 min
- Signal-to-quantization-noise ratio (SQNR) ~12 min
- Oversampled A/D and D/A conversion, noise shaping, and a first look at sigma-delta ~12 min
- Filter-coefficient quantization and pole/zero sensitivity ~12 min
- Limit cycles and overflow oscillation in fixed-point IIR filters ~12 min
- Finite-wordlength effects in FFT algorithms ~10 min
- What "no extensive math background" claims miss: calibrating this course's own difficulty honestly ~8 min
16 The 2D DSP connection: from signals to images π
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- Recalling 1D convolution and the 1D DFT ~10 min
- 1D vs. 2D signals: an image as a 2D array ~10 min
- 2D convolution ~12 min
- 2D correlation ~12 min
- The 2D DFT and separability ~12 min
- Spatial aliasing and 2D downsampling ~12 min
- What a dedicated Digital Image Processing course adds ~14 min