Modeling and Simulation for Composite Fading Channel

The traditional channel emulator usually only consider the effects of small scale fading caused by multipath propagation. A composite fading channel model including path loss, shadowing (known as large scale fading) and multipath fading is established, and a novel hardware generation method based on Gaussian decomposition and sum-of-sinusoids (SOS) theory is presented in this paper, which is suitable for hardware to realize. On this basis, the theoretical probability density function (PDF) of output fading envelope, as well as the relationship between output PDF and simulation parameters is derived. The periodicity of output fading sequences and data width selection for the fixed point model based on field programmable gate array (FPGA) are also analyzed. The experimental results for prototype emulator show that the output fading’s statistical properties agree well with the theoretical ones. So it can be used for performance evaluation and algorithm verification of wireless communication system in the lab.