itpp::Rice_Fading_Generator Class Reference
[Communication Channel Models]

Rice type Fading generator class. More...

#include <itpp/comm/channel.h>

Inheritance diagram for itpp::Rice_Fading_Generator:


Public Member Functions
	Rice_Fading_Generator (const double norm_doppler=0.0, const DOPPLER_SPECTRUM spectrum=Jakes, const int no_freq=16, const RICE_METHOD method=MEDS)
	Set normalized dopper, doppler spectrum, number of doppler frequencies and calculation method.
virtual	~Rice_Fading_Generator ()
	Destructor.
void	set_no_frequencies (const int no_freq)
	Set number of doppler frequencies.
void	set_method (const RICE_METHOD method)
	Set calculation method for calculation of doppler frequencies and amplitudes.
int	get_no_frequencies ()
	Get number of doppler frequencies.
RICE_METHOD	get_method ()
	Get calculation method for calculation of doppler frequencies and amplitudes.
virtual void	init ()
	Initialize the generator (is not needed) and set time offset to 0.
void	set_time_offset (const int offset)
	set time offset in samples
double	get_time_offset ()
	get time offset in samples
virtual void	generate (const int no_samples, cvec &output)
	Generate `no_samples` values from the fading process.
virtual void	generate (const int no_samples, const int upsampling_factor, cvec &output)
	Generate `no_samples` values from the fading process upsampled by `upsampling_factor`.
void	set_norm_doppler (const double norm_doppler)
	Set normalized doppler rate.
void	set_doppler_spectrum (const DOPPLER_SPECTRUM spectrum)
	Set doppler spectrum.
void	set_LOS (const double relative_power, const double relative_doppler)
	Set LOS component. Used e.g. for Rice doppler spectrum. Rice factor and relative doppler (related to maximum doppler).
double	get_norm_doppler ()
	Return normalized doppler rate.
DOPPLER_SPECTRUM	get_doppler_spectrum ()
	Return doppler spectrum.
double	get_LOS_power ()
	Get relative power of LOS component (Rice factor).
double	get_LOS_doppler ()
	Get relative doppler (compared to maximum doppler) for the LOS component.
cvec	generate (const int no_samples)
	Generate `no_samples` values from the fading process.
cvec	generate (const int no_samples, const int upsampling_factor)
	Generate `no_samples` values from the fading process upsampled by `upsampling_factor`.
void	shift_time_offset (const int no_samples)
	Shift generator time offset by a number of samples.
Protected Member Functions
void	init_MEDS ()
	Init function for MEDS method.
void	generate_zero_doppler (const int no_samples, cvec &output)
void	generate_zero_doppler (const int no_samples, const int upsampling_factor, cvec &output)
Protected Attributes
int	Ni
	Generate `no_samples` values from the fading process.
RICE_METHOD	rice_method
vec	f1
vec	f2
vec	c1
vec	c2
vec	th1
vec	th2
DOPPLER_SPECTRUM	dopp_spectrum
double	n_dopp
double	los_dopp
double	los_power
bool	init_flag
double	time_offset

Detailed Description

Rice type Fading generator class.

Author:: Tony Ottosson

A Rice generator is a generator of the form

$\tilde \mu_i(t) = \sum_{n=1}^{N_i} c_{i,n} \cos(2\pi f_{i,n} t + \theta_{i,n})$

Here $c_{i,n}$ , $f_{i,n}$ , and $\theta_{i,n}$ are the doppler coefficients, discrete doppler frequencies, and doppler phases, respectively. Rice showed that a generator of this form can perfectly model a Gaussian process when $N_i \leftarrow \infty$ . When generating a fading pattern we need a complex-valued generator

$\tilde \mu(t) = \tilde \mu_1(t) + j \tilde \mu_2(t)$

Parameters that define the generator is the normalized doppler and the doppler spectrum. Possible values of doppler spectra are:

Jakes, J, Classic, or C: for the classical Jakes spectrum shape
Rice or R: the classical Jakes spectrum and a direct tap. Observe that the LOS parameters also need to be set.
GaussI, GI, Gauss1, or G1
GaussII, GII, Gauss2, or G2

Furthermore also the number of doppler frequencies, $N_i$ and the method used to calculate the parameters $c_{i,n}$ , $f_{i,n}$ , and $\theta_{i,n}$ are parameters. For now the only method defined for calculating the parameters is the Method of Exact Doppler Spread (MEDS). See [P"atzold] for more details.

References:

[P"atzold] Matthias P"atzold, Mobile fading channels, Wiley, 2002.

Definition at line 301 of file channel.h.

Constructor & Destructor Documentation

itpp::Rice_Fading_Generator::Rice_Fading_Generator ( const double norm_doppler = 0.0,

const DOPPLER_SPECTRUM spectrum = Jakes,

const int no_freq = 16,

const RICE_METHOD method = MEDS

)

Set normalized dopper, doppler spectrum, number of doppler frequencies and calculation method.

Definition at line 144 of file channel.cpp.

virtual itpp::Rice_Fading_Generator::~Rice_Fading_Generator ( ) [inline, virtual]

Destructor.

Definition at line 307 of file channel.h.

Member Function Documentation

void itpp::Rice_Fading_Generator::set_no_frequencies ( const int no_freq )

Set number of doppler frequencies.

Definition at line 151 of file channel.cpp.

void itpp::Rice_Fading_Generator::set_method ( const RICE_METHOD method )

Set calculation method for calculation of doppler frequencies and amplitudes.

Definition at line 158 of file channel.cpp.

int itpp::Rice_Fading_Generator::get_no_frequencies ( )

Get number of doppler frequencies.

Definition at line 165 of file channel.cpp.

RICE_METHOD itpp::Rice_Fading_Generator::get_method ( )

Get calculation method for calculation of doppler frequencies and amplitudes.

Definition at line 170 of file channel.cpp.

void itpp::Rice_Fading_Generator::init ( ) [virtual]

Initialize the generator (is not needed) and set time offset to 0.

Implements itpp::Fading_Generator.
Definition at line 175 of file channel.cpp.

void itpp::Rice_Fading_Generator::set_time_offset ( const int offset )

set time offset in samples

Definition at line 190 of file channel.cpp.

double itpp::Rice_Fading_Generator::get_time_offset ( )

get time offset in samples

Definition at line 196 of file channel.cpp.

void itpp::Rice_Fading_Generator::generate ( const int no_samples,

cvec & output

) [virtual]

Generate no_samples values from the fading process.

Implements itpp::Fading_Generator.
Definition at line 201 of file channel.cpp.

void itpp::Rice_Fading_Generator::generate ( const int no_samples,

const int upsampling_factor,

cvec & output

) [virtual]

Generate no_samples values from the fading process upsampled by upsampling_factor.

Implements itpp::Fading_Generator.
Definition at line 227 of file channel.cpp.

void itpp::Rice_Fading_Generator::init_MEDS ( ) [protected]

Init function for MEDS method.

Definition at line 254 of file channel.cpp.

void itpp::Fading_Generator::set_norm_doppler ( const double norm_doppler ) [inherited]

Set normalized doppler rate.

Definition at line 72 of file channel.cpp.
References it_assert.

void itpp::Fading_Generator::set_doppler_spectrum ( const DOPPLER_SPECTRUM spectrum ) [inherited]

Set doppler spectrum.

Definition at line 79 of file channel.cpp.

void itpp::Fading_Generator::set_LOS ( const double relative_power,

const double relative_doppler

) [inherited]

Set LOS component. Used e.g. for Rice doppler spectrum. Rice factor and relative doppler (related to maximum doppler).

Definition at line 89 of file channel.cpp.

double itpp::Fading_Generator::get_norm_doppler ( ) [inline, inherited]

Return normalized doppler rate.

Definition at line 234 of file channel.h.

DOPPLER_SPECTRUM itpp::Fading_Generator::get_doppler_spectrum ( ) [inline, inherited]

Return doppler spectrum.

Definition at line 236 of file channel.h.
References itpp::DOPPLER_SPECTRUM.

double itpp::Fading_Generator::get_LOS_power ( ) [inline, inherited]

Get relative power of LOS component (Rice factor).

Definition at line 238 of file channel.h.

double itpp::Fading_Generator::get_LOS_doppler ( ) [inline, inherited]

Get relative doppler (compared to maximum doppler) for the LOS component.

Definition at line 240 of file channel.h.

cvec itpp::Fading_Generator::generate ( const int no_samples ) [inherited]

Generate no_samples values from the fading process.

Definition at line 99 of file channel.cpp.

cvec itpp::Fading_Generator::generate ( const int no_samples,

const int upsampling_factor

) [inherited]

Generate no_samples values from the fading process upsampled by upsampling_factor.

Definition at line 106 of file channel.cpp.

void itpp::Fading_Generator::shift_time_offset ( const int no_samples ) [inherited]

Shift generator time offset by a number of samples.

Definition at line 113 of file channel.cpp.

Member Data Documentation

int itpp::Rice_Fading_Generator::Ni [protected]

Generate no_samples values from the fading process.

Definition at line 335 of file channel.h.

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

itpp/comm/channel.h
itpp/comm/channel.cpp

Generated on Fri Jan 11 08:51:42 2008 for IT++ by Doxygen 1.3.9.1

itpp::Rice_Fading_Generator Class Reference [Communication Channel Models]

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

itpp::Rice_Fading_Generator Class Reference
[Communication Channel Models]