From: Fuzzy modeling, maximum likelihood estimation, and Kalman filtering for target tracking in NLOS scenarios
x c
x n
x ϵ
ϵ
Gaussian law
x m
x m  + 2.58σ
x m  + 1.54σ
0.12
Exponent law
x m  + 3.2σ
x m  + 1.46σ
0.13
Triangular law
x m  + 2.45σ
x m  + 1.63σ
0.11
Uniform law
x m  + 1.73σ
0