Understanding Digital Filtering - Part 1 скачать в хорошем качестве

Understanding Digital Filtering - Part 1

This is the first in a series of videos that will look at digital filtering. For this video, I'm looking at how Gnu Radio creates a lowpass FIR (finite impulse response) filter. All of the flowgraphs used in this video are available on my Github: https://github.com/JesterNoFool/grc Music Credit: "Electric Throne" Video sections: 00:00: Intro 00:23: Overview of digital filtering 01:31: Review of FM broadcast receiver filter 01:59: Signal categories 02:13: Types of signal isolation filters 02:34: Brief review of convolution 03:28: Filter impulse response 05:57: Lowpass filter frequency response 06:57: Frequency responses of HP, BP and BR filters. 07:32: Time-frequency duality of sinc curve and square pulse 08:24: Square pulse in time domain = sinc curve in frequency domain 10:25: Creating a filter with a sinc pulse 12:24: Reasons for adding a window to sinc pulse 13:45: Filter parameters changed based on windowing 14:34: Bands of a filter 15:18: Filter length vs transition band width 16:15: Combining a window and sinc pulse 17:48: How the filter is implemented 23:02: How the filter taps are created 23:28: The relation between cutoff frequency and sinc curve 24:15: The relation between transition width and filter length 24:43: Calculating the number of taps (harris approximation) 25:43: Calculating the sinc curve & window based on number of taps 26:16: How the final filter is implemented in the time domain 28:09: Summary of process