comnum.ls_noise_factor

comnum.ls_noise_factor(points)

The noise enhancement of LS estimates over a constellation, beta = E|x|^2 E|1/x|^2 (Edfors et al. 1998): 1 for a constant modulus, 17/9 for 16-QAM.

Parameters:

points (array_like) – the points of the constellation (complex), equiprobable.

Returns:

beta.

Return type:

float

Raises:

ValueError – for no point or a point at the origin.

Example

>>> import comnum
>>> round(comnum.ls_noise_factor(comnum.Constellation("qam", 16).points) * 9, 9)
17.0