Investigation of small-scale fading in indoor peerto-peer networks based on radio channel measurements shows that Rayleigh or double-Rayleigh fading with or without lineof-sight (LOS) component can occur, depending on the mobility and on the scattering properties of the environment. While in double-mobile scenarios, the predominant fading mechanism is a combination of Rayleigh and double-Rayleigh fading, Rician fading and fading events caused by combination of a constant term with a Double Rayleigh component are also occasionally observed. In single-mobile scenarios, temporal fading is Rician or Rayleigh distributed. Additionally, measurements reveal that fading statistics evolve significantly over time, even for smallscale motions of the nodes. We model the transitions between the fading states by means of a hidden Markov model, parameterized from our measurements. Eventually, we propose a complete simulation model that generates channel realizations by combining measurement-based first-order statistics with geometry-based second-order statistics for both types of node mobility.