Fast Rayleigh fading simulation with an IIR filter and polyphase interpolation

摘要

In wireless transmission scenarios where a receiver is in motion relative to a transmitter with no line-of-sight path between their antennas, Rayleigh fading is often a good approximation of realistic channel conditions. The term Rayleigh fading channel refers to a multiplicative distortion h(t) of the transmitted signal s(t), as in y(t) = h(t) · s(t) + n(t), where y(t) is the received waveform and nft) is the noise. The design of a simulator presented here mimics a sampled version of the channel waveform h(t) in a statistically accurate and computationally efficient fashion. This simulator exists as one of the channel models in the Visual System Simulator (VSS). The channel waveform h(t) is modeled as a wide-sense-stationary complex Gaussian process with zero mean, which makes the marginal distributions of the phase and amplitude at any given time uniform and Rayleigh, respectively, hence the term Rayleigh fading.