https://www.mathworks.com/help/comm/ref/noisebw.html
noisebw - Equivalent noise bandwidth of digital lowpass filter - MATLAB
This MATLAB function returns the two-sided equivalent noise bandwidth of a digital lowpass filter in Hz.
equivalent noise bandwidthlowpass filterdigitalmatlab
https://www.mathworks.com/help/signal/ref/enbw.html
enbw - Equivalent noise bandwidth - MATLAB
This MATLAB function returns the two-sided equivalent noise bandwidth, bw, for a uniformly sampled window, window.
equivalent noise bandwidthenbwmatlab