This paper mainly deals with the indoor wireless propagation channel under line of sight (LOS) and non-line of sight (NLOS) propagation conditions, introducing the reference model and studing the design and simulation of modeling and the relevant statistical properties. This paper will present a comprehensive and improved indoor reference channel model based on a geometric scattering model. The reference channel model assumes that infinite number of scatterers will be uniformly distributed on the two-dimensional (2D) horizontal plane of a three-dimensional space. This paper also derives analytical expressions for the probability density function (PDF) of the angle-of-arrival (AOA), the Doppler power spectral density (PSD), and the temporal autocorrelation function (ACF) of an electromagnetic arrival signal; it also analyzes the influences of the important parameters of the functions. It presents a highly efficient sum-of-cisoids (SOC) channel simulation model from the unrealistic reference model, also proposes two efficient parameter computation methods for the design of sum-of-cisoids indoor channel simulation model and compares the computing performances of both. It is shown by simulation results that the statistical properties of the sum-of-cisoids channel simulation model match perfectly the reference channel model. It turns out that the indoor reference model can be approximated by an SOC channel simulation model. Meanwhile the channel simulation model can be well applied to evaluate the performance of indoor wireless communication systems. It also extends the research for indoor wireless channel modeling while reduces the realization expenditure.