# What is Nakagami-m fading channel?

## What is Nakagami-m fading channel?

Nakagami-m fading channels are generally used to model multiple paths fading. \$m\$ refers to the fading order. The parameter m is called the ‘shape factor’ of the Nakagami or the gamma distribution. For m > 1, the fluctuations of the signal strength reduce compared to Rayleigh fading.

## What is the PDF of Nakagami distribution?

Nakagami-m probability density function (pdf) is one of the frequently used distributions for describing fast received signal variations in radio channels, obtained as a result of multipath phenomenon. It is foremost derived by assuming the most general multipath channel model but applying mathematical approximations.

Rayleigh fading is a statistical model for the effect of a propagation environment on a radio signal, such as that used by wireless devices. Rayleigh fading is most applicable when there is no dominant propagation along a line of sight between the transmitter and receiver.

### What is rician fading channel?

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 a Nakagami?

The Nakagami distribution (also called the Nakagami-m or Nakagami-μ distribution) is a fairly new probability distribution, first appearing in 1960. It is a generalized way to model small scale fading for dense signal scatters and it one of the most common distributions for modeling right-skewed, positive data sets.

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.

## Why is Rayleigh fading used?

The Rayleigh fading model can be used to analyse radio signal propagation on a statistical basis. It operates best under conditions when there is no dominant signal (e.g. direct line of sight signal), and in many instances cellular telephones being used in a dense urban environment fall into this category.

## What is the difference between Rayleigh and Rician fading?

Rayleigh fading is most applicable when there is no dominant line-of-sight propagation between the transmitter and receiver. 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.

What is K-factor in rician fading?

Rician K-factor The Rician K-factor is defined as the ratio of signal power in dominant component over the (local-mean) scattered power. Thus. The total local-mean power is the sum of the power in the line-of-sight and the local-mean scattered power.

### What is Sigma in Rayleigh?

When a Rayleigh is set with a shape parameter (σ) of 1, it is equal to a chi square distribution with 2 degrees of freedom. The notation X Rayleigh(σ) means that the random variable X has a Rayleigh distribution with shape parameter σ. The probability density function (X > 0) is: Where e is Euler’s number.