ns3::JakesPropagationLossModel Class Reference

a Jakes propagation loss model More...

#include <jakes-propagation-loss-model.h>

Inheritance diagram for ns3::JakesPropagationLossModel:

Collaboration diagram for ns3::JakesPropagationLossModel:

List of all members.

Public Member Functions

void SetNRays (uint8_t nRays)

void SetNOscillators (uint8_t nOscillators)

Static Public Member Functions

static TypeId GetTypeId (void)

This method returns the TypeId associated to ns3::JakesPropagationLossModel.

Detailed Description

a Jakes propagation loss model

The Jakes propagation loss model implemented here is described in [1].

We call path the set of rays that depart from a given transmitter and arrive to a given receiver. For each ray The complex coefficient is compute as follow:

$u(t)=u_c(t) + j u_s(t)$

$u_c(t) = \frac{2}{\sqrt{N}}\sum_{n=0}^{M}a_n\cos(\omega_n t+\phi_n)$

$u_s(t) = \frac{2}{\sqrt{N}}\sum_{n=0}^{M}b_n\cos(\omega_n t+\phi_n)$

where

$a_n=\left \{ \begin{array}{ll} \sqrt{2}\cos\beta_0 & n=0 \\ 2\cos\beta_n & n=1,2,\ldots,M \end{array} \right .$

$b_n=\left \{ \begin{array}{ll} \sqrt{2}\sin\beta_0 & n=0 \\ 2\sin\beta_n & n=1,2,\ldots,M \end{array} \right .$

$\beta_n=\left \{ \begin{array}{ll} \frac{\pi}{4} & n=0 \\ \frac{\pi n}{M} & n=1,2,\ldots,M \end{array} \right .$

$\omega_n=\left \{ \begin{array}{ll} 2\pi f_d & n=0 \\ 2\pi f_d \cos\frac{2\pi n}{N} & n=1,2,\ldots,M \end{array} \right .$

The parameter $f_d$ is the doppler frequency and $N=4M+2$ where $M$ is the number of oscillators per ray.

The attenuation coefficent of the path is the magnitude of the sum of all the ray coefficients. This attenuation coefficient could be greater than $1$ , hence it is divide by $\frac{2N_r}{\sqrt{N}} \sum_{n+0}^{M}\sqrt{a_n^2 +b_n^2}$ where $N_r$ is the number of rays.

The initail phases $\phi_i$ are random and they are choosen according to a given distribution.

[1] Y. R. Zheng and C. Xiao, "Simulation Models With Correct Statistical Properties for Rayleigh Fading Channel", IEEE Trans. on Communications, Vol. 51, pp 920-928, June 2003

Member Function Documentation

static TypeId ns3::JakesPropagationLossModel::GetTypeId ( void ) [static]

This method returns the TypeId associated to ns3::JakesPropagationLossModel.

Attributes defined for this type:

NumberOfRaysPerPath: The number of rays to use by default for compute the fading coeficent for a given path (default is 1)
- Set with class: ns3::UintegerValue
- Underlying type: uint8_t 0:255
- Initial value: 1
- Flags: construct write read
NumberOfOscillatorsPerRay: The number of oscillators to use by default for compute the coeficent for a given ray of a given path (default is 4)
- Set with class: ns3::UintegerValue
- Underlying type: uint8_t 0:255
- Initial value: 4
- Flags: construct write read
DopplerFreq: The doppler frequency in Hz (f_d = v / lambda = v * f / c), the default is 0)
- Set with class: ns3::DoubleValue
- Underlying type: double -1.79769e+308:1.79769e+308
- Initial value: 0
- Flags: construct write read
Distribution: The distribution to choose the initial phases.
- Set with class: RandomVariableValue
- Underlying type: RandomVariable
- Initial value: Constant:1
- Flags: construct write read

No TraceSources defined for this type.

Reimplemented from ns3::PropagationLossModel.

void ns3::JakesPropagationLossModel::SetNOscillators ( uint8_t nOscillators )

Parameters:

nOscillators

Number of oscillators

Set the number of oscillators to use to compute the ray coefficient

void ns3::JakesPropagationLossModel::SetNRays ( uint8_t nRays )

Parameters:

nRays

Number of rays per path

Set the number of rays for each path

The documentation for this class was generated from the following files:

src/devices/wifi/jakes-propagation-loss-model.h
doc/introspected-doxygen.h


Public Member Functions
void	SetNRays (uint8_t nRays)
void	SetNOscillators (uint8_t nOscillators)
Static Public Member Functions
static TypeId	GetTypeId (void)
	This method returns the TypeId associated to ns3::JakesPropagationLossModel.