HTranslateByFour< T > Class Template Reference

#include <htranslatebyfour.h>

Inheritance diagram for HTranslateByFour< T >:

Collaboration diagram for HTranslateByFour< T >:

Public Member Functions
	HTranslateByFour (HWriter< T > *writer, size_t blocksize, bool isQ=false, HProbe< T > *probe=NULL)
	HTranslateByFour (HWriterConsumer< T > *consumer, size_t blocksize, bool isQ=false, HProbe< T > *probe=NULL)
	HTranslateByFour (HReader< T > *reader, size_t blocksize, bool isQ=false, HProbe< T > *probe=NULL)
	~HTranslateByFour ()
void	Filter (T *src, T *dest, size_t blocksize)
void	SetIsQ (bool isQ)
Public Member Functions inherited from HFilter< T >
	~HFilter ()
int	Write (T *src, size_t blocksize)
int	Read (T *dest, size_t blocksize)
bool	Start ()
bool	Stop ()
bool	Command (HCommand *command)
void	Enable ()
void	Disable ()
bool	GetEnabled ()
Public Member Functions inherited from HObject
	HObject ()
Public Member Functions inherited from HWriter< T >
virtual	~HWriter ()=default
HWriter< T > *	Writer ()
Public Member Functions inherited from HReader< T >
virtual	~HReader ()=default
HReader< T > *	Reader ()
Public Member Functions inherited from HWriterConsumer< T >
HWriterConsumer< T > *	Consumer ()

Static Public Member Functions
static void	Translate (T *src, std::complex< T > *dest, size_t blocksize)
static void	Translate (T *src, std::complex< double > *dest, size_t blocksize)
Static Public Member Functions inherited from HFilter< T >
static std::vector< float >	ReadCoeffsFromFile (std::string filename)
static std::vector< float >	ReadCoeffsFromFile (char *filename)

Additional Inherited Members
Protected Member Functions inherited from HFilter< T >
	HFilter (HWriter< T > *writer, size_t blocksize, HProbe< T > *probe=NULL)
	HFilter (HWriterConsumer< T > *consumer, size_t blocksize, HProbe< T > *probe=NULL)
	HFilter (HReader< T > *reader, size_t blocksize, HProbe< T > *probe=NULL)
void	SetWriter (HWriter< T > *writer)
Protected Attributes inherited from HFilter< T >
int	_blocksize

Detailed Description

template<class T>
class HTranslateByFour< T >

Translating the input samples by four.

This implements the common frequency translation method of translating by four, either cos(PI*n) or sin(PI*n) at fs/4 by multiplying with [1, 0, -1, 0, 1, .... ] or [0, -1, 0, 1, 0, .... ]

The result is either the real or imaginary (I or Q) signal of a quadrature signal decimated by 4 and with the center frequency shifted to 0.

You can think if this as the output being either the I or Q branch of an combined IQ signal. If you look at the branches in a realvalued fft, you will find that

1) The input spectrum [0 - fs/4] will appear shifted up past fs/4 2) The input spectrum [0 - fs/4] will also appear as shifted towards 0 AND inverted.

Components above fs/4 will be shifted towards 0 not-inverted, but you will get an alias centered and to the left of fs/4.

The flag 'isQ' simply signifies if you wants to multiply with cos or sin (isQ)

Constructor & Destructor Documentation

HTranslateByFour() [1/3]

template<class T >

HTranslateByFour< T >::HTranslateByFour ( HWriter< T > *  writer, size_t  blocksize, bool  isQ = false, HProbe< T > *  probe = NULL  )

inline

Construct a new HTranslateByFour object that writes to a writer

HTranslateByFour() [2/3]

template<class T >

HTranslateByFour< T >::HTranslateByFour ( HWriterConsumer< T > *  consumer, size_t  blocksize, bool  isQ = false, HProbe< T > *  probe = NULL  )

inline

Construct a new HTranslateByFour object that registers with an upstream writer

HTranslateByFour() [3/3]

template<class T >

HTranslateByFour< T >::HTranslateByFour ( HReader< T > *  reader, size_t  blocksize, bool  isQ = false, HProbe< T > *  probe = NULL  )

inline

Construct a new HTranslateByFour object that reads from a reader

~HTranslateByFour()

template<class T >

HTranslateByFour< T >::~HTranslateByFour ( )

inline

Default destructor

Member Function Documentation

Filter()

template<class T >

void HTranslateByFour< T >::Filter ( T *  src, T *  dest, size_t  blocksize  )

inlinevirtual

Run a block of samples through the translator

Implements HFilter< T >.

SetIsQ()

template<class T >

void HTranslateByFour< T >::SetIsQ ( bool  isQ )

inline

Change direction of the shift

Parameters

isQ	shift direction, false=down, true=up

Translate() [1/2]

template<class T >

static void HTranslateByFour< T >::Translate ( T *  src, std::complex< double > *  dest, size_t  blocksize  )

inlinestatic

Convert the realvalued input signal 'src' to a complex IQ signal

Translate() [2/2]

template<class T >

static void HTranslateByFour< T >::Translate ( T *  src, std::complex< T > *  dest, size_t  blocksize  )

inlinestatic

Convert the realvalued input signal 'src' to a complex IQ signal

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

• /home/henrik/Git/Hardt/hardt/libhardt/include/htranslatebyfour.h
• /home/henrik/Git/Hardt/hardt/libhardt/filters/htranslatebyfour.cpp