  Subdiffusive behavior of one-dimensional stochastic systems can be described
by time-subordinated Langevin equations. The corresponding probability density
satisfies the time-fractional Fokker-Planck equations. In the homogeneous
systems the power spectral density of the signals generated by such Langevin
equations has power-law dependency on the frequency with the exponent smaller
than 1. In this paper we consider nonhomogeneous systems and show that in such
systems the power spectral density can have power-law behavior with the
exponent equal to or larger than 1 in a wide range of intermediate frequencies.
