What causes rician fading?
What causes rician fading?
Rician fading or Ricean fading is a stochastic model for radio propagation anomaly caused by partial cancellation of a radio signal by itself — the signal arrives at the receiver by several different paths (hence exhibiting multipath interference), and at least one of the paths is changing (lengthening or shortening).
What is rician factor?
Rician factor The Rician K-factor is defined as the ratio of signal power in dominant component over the (local-mean) scattered power. In the expression for the received signal, the power in the line-of-sight equals C2/2. Rayleigh fading is recovered for K = 0 (-infinity dB).
What is the difference between Rayleigh and Rician fading?
Rayleigh fading model assumes that the magnitude of a signal that has passed through transmission medium will vary randomly, or fade, according to a Rayleigh distribution. Rician model considers that the dominant wave can be a phasor sum of two or more dominant signals, e.g. the line-of-sight, plus a ground reflection.
In what conditions Rayleigh and Rician fading is observed?
Rayleigh fading is most applicable when there is no dominant propagation along a line of sight between the transmitter and receiver. If there is a dominant line of sight, Rician fading may be more applicable. Rayleigh fading is a special case of two-wave with diffuse power (TWDP) fading.
What is rician fading model?
What is the difference between flat fading and selective fading?
➨In flat fading, range of frequencies in a frequency spectrum are equally faded unlike in frequency selective fading where in one part of frequency spectrum is faded more than the other part of frequency spectrum.
What is Ricean K factor?
In wireless communication, Ricean K factor which is the relative strength of the direct and scattered components of the received signal, is an important reflection of channel quality parameters.
What is slow and fast fading?
Slow fading can be caused by events such as shadowing, where a large obstruction such as a hill or large building obscures the main signal path between the transmitter and the receiver. Fast fading occurs when the coherence time of the channel is small relative to the delay requirement of the application.
Is Rayleigh fading fast fading?
It is also called Rayleigh Fading. Small Scale Fading affects almost all forms of wireless communication and overcoming them is a necessity to increase efficiency and decrease error. Fast Fading: It occurs mainly due to reflections for surfaces and movement of transmitter or receiver.
What is fading in wireless communication?
In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency. Fading is often modeled as a random process. A fading channel is a communication channel that experiences fading.
Why do frequency selective fading occur?
Frequency selective fading occurs when the symbol length is shorter than the delay spread, or equivalently when signal bandwidth is larger than the channel bandwidth.
What is slow fading and fast fading?
Which is a special case of Rician fading?
Rayleigh fading is a special case of Rician fading with the Rician parameter K set to K = 0. It is known to lead to deeper fades and worse propagation scenarios [30]. Since the value of the Rician parameter generally varies along the train track, we will consider Rayleigh fading in this paper.
Why is the channel coefficient called Rician fading?
Under these assumptions, the magnitude of the channel coefficient is Rice/Rician distributed, which is why it is called Rician fading. More precisely, , which depends on the magnitude and the variance of the scattering.
What’s the difference between Rayleigh fading and Rician fading?
In this paper, the performances of both the Rayleigh and Rician fading channels are analyzed under frequencyselective fading, in terms of error probability, and it is shown that due to the presence of an LOS component, the Rician fading exhibits less error probability than the Rayleigh fading.
Which is the random variable for Rician flat fading?
With respect to the simulation model shown in Figure 1 (b), given a K factor, the samples for the Rician flat-fading samples are drawn from the following random variable where X,Y ~ N (μ,σ2) are Gaussian random variables with non-zero mean μ and standard deviation σ as given in references [2] and [3].