bw = enbw(window)
returns the two-sided equivalent noise bandwidth, bw,
for a uniformly sampled window, window. The equivalent
noise bandwidth is normalized by the noise power per frequency bin.

Obtain the equivalent rectangular noise bandwidth
of a Von Hann window and overlay the equivalent rectangular bandwidth
on the window's magnitude spectrum. The window is 1000 samples
in length and the sampling frequency is 10 kHz.

Set the sampling frequency, create the window, and obtain
the discrete Fourier transform of the window with 0 frequency in the
center of the spectrum.

The equivalent noise bandwidth of a window is the width of a
rectangle whose area contains the same total power as the window.
The height of the rectangle is the peak squared magnitude of the window's
Fourier transform.

Assuming a sampling interval of 1, the total energy for the
window, w(n), can be expressed in the frequency
or time-domain as

The peak magnitude of the window's spectrum occurs at f=0.
This is given by

To find the width of the equivalent rectangular bandwidth, divide
the area by the height.

See Equivalent Rectangular Noise Bandwidth for an example that
plots the equivalent rectangular bandwidth over the magnitude spectrum
of a Von Hann window.