Data Converters EECT 7327 DiscreteTime Signal Processing Fall

Data Converters EECT 7327 Discrete-Time Signal Processing Fall 2014 Professor Y. Chiu Discrete-Time Signal Processing (A Review) – 1–

Data Converters EECT 7327 Discrete-Time Signal Processing Fall 2014 Professor Y. Chiu Sampling CT DT – 2–

Data Converters EECT 7327 Discrete-Time Signal Processing Fall 2014 Professor Y. Chiu Zero-Order Hold (ZOH) – 3–

Data Converters EECT 7327 Discrete-Time Signal Processing Fall 2014 Professor Y. Chiu Sampling Impulse train – 4–

Data Converters EECT 7327 Discrete-Time Signal Processing Fall 2014 Professor Y. Chiu Sampling δ(t-n. T) – 5–

Data Converters EECT 7327 Discrete-Time Signal Processing Fall 2014 Professor Y. Chiu Spectrum of Sampled Signal (Ωs>2ΩN) The spectrum of the sampled signal is periodic in Ωs=2π/T. – 6–

Data Converters EECT 7327 Discrete-Time Signal Processing Fall 2014 Professor Y. Chiu Spectrum of Sampled Signal (Ωs<2ΩN) • • Aliasing (folding) results in irreversible signal distortion. Can only be avoided by using sufficiently high sample rate, or bandlimit the input signal with a coarse, continuous-time filter – AAF. – 7–

Data Converters EECT 7327 Discrete-Time Signal Processing Fall 2014 Professor Y. Chiu Reconstruction Filter (Nyquist) Reconstruction filter = “smoothing” filter = “interpolation” filter – 8–