Two-ray Rayleigh Fading Model
In modern mobile communication systems with high data rates, it has become necessary to model the effects of multipath delay spread as well as fading. A commonly used multipath model is an independent Rayleigh fading 2-ray model.Figure 11.10 shows a block diagram of the 2-ray independent Rayleigh fading channel model
The impulse response of the model is represented as
- where α1andα2 are independent and Rayleigh distributed, É¸ 1and É¸ 2are independent and uniformly distributed over [0, 2π] , and τ is the time delay the two rays.
- By setting a, equal to zero, the special case of a flat Rayleigh fading channel is obtained as â€• (2)
- By varying τ, it is possible to create a wide range of frequency selective fading effects.
- The proper time correlation properties of the Rayleigh random variables α1 andα2are guaranteed by generating two independent waveforms, each produced from the inverse Fourier transform of the spectrum