Note 22. Assessing Window Functions: Sinusoidal Analysis Techniques
When a window is employed to reduce leakage in the DFT, the window’s DTFT response can be used directly in one of two ways to assess the DFT’s output due to known (or approximately known) sinusoidal components in the input signal.
• The bin-centric approach, detailed in Recipe 22.1, determines the response of a single DFT bin to signals over the entire range of frequencies supported by the chosen sampling rate (i.e., the frequency range –(2T)–1 to (2T)–1).
• The signal-centric approach, detailed in Recipe 22.2, determines the response of every DFT bin to a signal component consisting of a single sinusoid at frequency fc.