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itpp::Rice_Fading_Generator Class Reference
[Channel Modeling]

#include <itpp/comm/channel.h>

Inheritance diagram for itpp::Rice_Fading_Generator:

itpp::Correlated_Fading_Generator itpp::Fading_Generator

List of all members.


Detailed Description

Rice type fading generator class.

Author:
Tony Ottosson, Adam Piatyszek and Zbigniew Dlugaszewski
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 \rightarrow \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 are the normalized Doppler and the doppler spectrum. Possible values of the Doppler spectrum are:

Furthermore also the number of sine waves, $ N_i $ and method used to calculate the parameters $ c_{i,n} $, $ f_{i,n} $, and $ \theta_{i,n} $ can be specified. For now the only method defined for calculating the parameters is the Method of Exact Doppler Spread (MEDS). See [Pat02] for more details.

References:

Definition at line 429 of file channel.h.


Public Member Functions

 Rice_Fading_Generator (double norm_doppler, DOPPLER_SPECTRUM spectrum=Jakes, int no_freq=16, RICE_METHOD method=MEDS)
 Default constructor.
virtual ~Rice_Fading_Generator ()
 Destructor.
virtual void set_doppler_spectrum (DOPPLER_SPECTRUM spectrum)
 Set Doppler spectrum.
virtual void set_no_frequencies (int no_freq)
 Set number of Doppler frequencies.
virtual void set_rice_method (RICE_METHOD method)
 Set calculation method of Doppler frequencies and amplitudes.
virtual DOPPLER_SPECTRUM get_doppler_spectrum () const
 Return Doppler spectrum.
virtual int get_no_frequencies () const
 Get number of Doppler frequencies.
virtual RICE_METHOD get_rice_method () const
 Get calculation method of Doppler frequencies and amplitudes.
virtual void init ()
 Initialize the generator.
virtual void generate (int no_samples, cvec &output)
 Generate no_samples values from the fading process.
virtual void set_norm_doppler (double norm_doppler)
 Set normalized Doppler.
virtual void set_LOS_doppler (double relative_doppler)
 Set relative Doppler (compared to the maximum Doppler) for the LOS component.
virtual void set_time_offset (int offset)
 Set time offset in samples.
virtual double get_norm_doppler () const
 Return normalized Doppler.
virtual double get_LOS_doppler () const
 Get relative Doppler (compared to the maximum doppler) for the LOS component.
virtual double get_time_offset () const
 Get time offset in samples.
virtual void shift_time_offset (int no_samples)
 Shift generator time offset by a number of samples.
cvec generate (int no_samples)
 Generate no_samples values from the fading process.
void set_LOS_power (double relative_power)
 Set relative LOS power.
virtual void set_filter_length (int filter_length)
 Set FIR filter length (for FIR fading generator).
double get_LOS_power () const
 Get relative power of LOS component (Rice factor).
virtual int get_filter_length () const
 Set FIR filter length (for FIR fading generator).

Protected Member Functions

void init_MEDS ()
 Init function for MEDS method.
void add_LOS (int idx, std::complex< double > &sample)
 add LOS component to the sample with index idx

Protected Attributes

DOPPLER_SPECTRUM dopp_spectrum
int Ni
 Number of sine waves in a Gaussian process.
RICE_METHOD rice_method
 Rice process generation method.
double n_dopp
 Normalized maximum Doppler frequency.
double los_dopp
 Relative Doppler on LOS component (0.7 by default).
double time_offset
 Time offset in samples (time state in the generator).
bool init_flag
 signals if generator is initialized or not
double los_power
 Relative power of LOS component compared to diffuse component (K factor).
double los_diffuse
 Diffuse component: sqrt(1 / (1 + los_power)).
double los_direct
 Direct component: sqrt(los_power / (1 + los_power)).
vec f1
vec f2
vec c1
vec c2
vec th1
vec th2
double f01
double f02

Member Data Documentation

Doppler spectrum type (Jakes by default)

Definition at line 460 of file channel.h.

Referenced by generate(), get_doppler_spectrum(), init_MEDS(), and set_doppler_spectrum().

Doppler frequencies, amplitudes and phases

Definition at line 467 of file channel.h.

Referenced by generate(), and init_MEDS().

Doppler frequencies, amplitudes and phases

Definition at line 467 of file channel.h.

Referenced by generate(), and init_MEDS().

Doppler frequencies, amplitudes and phases

Definition at line 467 of file channel.h.

Referenced by generate(), and init_MEDS().

Doppler frequencies, amplitudes and phases

Definition at line 467 of file channel.h.

Referenced by generate(), and init_MEDS().

Doppler frequencies, amplitudes and phases

Definition at line 467 of file channel.h.

Referenced by generate(), and init_MEDS().

Doppler frequencies, amplitudes and phases

Definition at line 467 of file channel.h.

Referenced by generate(), and init_MEDS().

Frequency shift values of the Doppler spectrum in GaussI and GaussII

Definition at line 471 of file channel.h.

Referenced by generate(), and init_MEDS().

Frequency shift values of the Doppler spectrum in GaussI and GaussII

Definition at line 471 of file channel.h.

Referenced by generate(), and init_MEDS().


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