  In this paper, we present statistical simulators for cascaded Rayleigh fading
channels with and without line-of-sight (LOS). These simulators contain two
individual summations and are therefore easy to implement with lower
complexity. Detailed statistical properties, including auto- and
cross-correlations of the in-phase, quadrature components of the channels,
envelopes, and squared envelopes, are derived. The time-average statistical
properties and the corresponding variance are also investigated to justify that
the proposed simulators achieve good convergence performance.
  Extensive Monte Carlo simulations are performed for various statistical
properties to validate the proposed simulators. Results show that the
simulators provide fast convergence to all desired statistical properties,
including the probability density function (PDF), various auto- and
cross-correlations, level crossing rate (LCR), and average fading duration
(AFD).
  While various tests and measurements in dense scattering urban and forest
environments indicate that mobile-to-mobile channels may experience cascaded
Rayleigh fading, the proposed statistical models can be applied to simulate the
underlying channels.
