This class performs several operations on the complex (integral) input stream, it first filters out some part of the input stream using a FIR band pass (band pass is centerred around Ff with width width) then shifts the center frequency Fc to 0 and finally sub-samples the resulting stream. More...

#include <baseband.hh>

Inheritance diagram for sdr::IQBaseBand< Scalar >:

Public Types
typedef std::complex< Scalar >	CScalar
	The complex type of the input stream. More...

typedef int32_t	SScalar
	The (real) computation scalar type (super scalar), the computations are performed with this scalar type. More...

typedef std::complex< SScalar >	CSScalar
	Complex `SScalar` type. More...

Public Types inherited from sdr::FreqShiftBase< Scalar >
typedef std::complex< Scalar >	CScalar
	The complex input signal. More...

typedef Traits< Scalar >::SScalar	SScalar
	The compute (super) scalar of the input type. More...

typedef std::complex< SScalar >	CSScalar
	The complex compute (super) scalar of the input type. More...

Public Member Functions
	IQBaseBand (double Fc, double width, size_t order, size_t sub_sample, double oFs=0.0)
	Constructor, the filter center frequency `Ff` equals the given center frequency `Fc`. More...

	IQBaseBand (double Fc, double Ff, double width, size_t order, size_t sub_sample, double oFs=0.0)
	Constructor. More...

virtual	~IQBaseBand ()
	Destructor. More...

size_t	order () const
	Returns the order of the band-pass filter. More...

void	setOrder (size_t o)
	(Re-) Sets the filter order. More...

double	centerFrequency () const
	Returns the center frequency. More...

void	setCenterFrequency (double Fc)
	Resets the center frequency. More...

double	filterFrequency () const
	Returns the filter frequency. More...

void	setFilterFrequency (double Ff)
	(Re-) Sets the filter frequency. More...

double	filterWidth () const
	Returns the filter width. More...

void	setFilterWidth (double width)
	Sets the filter width. More...

size_t	subSample () const
	Returns the sub sampling. More...

void	setSubsample (size_t sub_sample)
	Resets the sub sampling. More...

void	setOutputSampleRate (double Fs)
	Resets the output sample rate. More...

virtual void	config (const Config &src_cfg)
	Configures the BaseBand node. More...

virtual void	process (const Buffer< std::complex< Scalar > > &buffer, bool allow_overwrite)
	Processes the given buffer. More...

Public Member Functions inherited from sdr::Sink< std::complex< Scalar > >
	Sink ()
	Constructor. More...

virtual	~Sink ()
	Drestructor. More...

virtual void	handleBuffer (const RawBuffer &buffer, bool allow_overwrite)
	Re-implemented from `SinkBase`. More...

Public Member Functions inherited from sdr::SinkBase
	SinkBase ()
	Constructor. More...

virtual	~SinkBase ()
	Destructor. More...

Public Member Functions inherited from sdr::Source
	Source ()
	Constructor. More...

virtual	~Source ()
	Destructor. More...

virtual void	send (const RawBuffer &buffer, bool allow_overwrite=false)
	Sends the given buffer to all connected sinks. More...

void	connect (SinkBase *sink, bool direct=false)
	Connect this source to a sink. More...

void	disconnect (SinkBase *sink)
	Disconnect a sink again. More...

virtual void	setConfig (const Config &config)
	Stores the configuration and propergates it if the configuration has been changed. More...

virtual double	sampleRate () const
	Returns the configured sample rate or `0` otherwise. More...

virtual Config::Type	type () const
	Returns the configured source type or `Config::Type_UNDEFINED` otherwise. More...

template<class T >
void	addEOS (T instance, void(T::function)())
	Adds a callback to the end-of-stream signal of the source. More...

Public Member Functions inherited from sdr::FreqShiftBase< Scalar >
	FreqShiftBase (double F, double Fs)
	Constructor. More...

virtual	~FreqShiftBase ()
	Destructor. More...

double	sampleRate () const
	Returns the sample rate. More...

virtual void	setSampleRate (double Fs)
	Sets the sample rate and updates the LUT. More...

double	frequencyShift () const
	Returns the frequency shift. More...

virtual void	setFrequencyShift (double F)
	Sets the frequency shift and updates the LUT. More...

CSScalar	applyFrequencyShift (CSScalar value)
	Performs the frequency shift on a single sample. More...

Protected Member Functions
void	_reconfigure ()
	Reconfigures the node. More...

void	_process (const Buffer< CScalar > &in, const Buffer< CScalar > &out)
	Performs the base-band selection, frequency shift and sub-sampling. More...

CSScalar	_filter_ring () const
	Applies the filter on the data stored in the ring buffer. More...

void	_update_filter_kernel ()
	Updates the band-pass filter kernel. More...

Protected Member Functions inherited from sdr::Source
void	signalEOS ()
	Signals the EOS. More...

void	propagateConfig (const Config &config)
	Propagates the given configuration to all connected sinks. More...

Protected Member Functions inherited from sdr::FreqShiftBase< Scalar >
void	_update_lut_incr ()
	Updates the multiplier LUT. More...

Protected Attributes
int32_t	_Fc
	The frequency shift of the base band. More...

int32_t	_Ff
	The center frequency of the base band. More...

int32_t	_Fs
	The input sample rate. More...

int32_t	_width
	The filter width. More...

size_t	_order
	The order of the filter. More...

size_t	_sub_sample
	The number of sample averages for the sub sampling. More...

double	_oFs
	Holds the desired output sample rate, _sub_sample will be adjusted accordingly. More...

size_t	_ring_offset
	The current index of the ring buffer. More...

size_t	_sample_count
	Holds the current number of samples averaged. More...

CSScalar	_last
	Holds the current sum of the last `_sample_count` samples. More...

size_t	_sourceBs
	Buffer size of the source. More...

Buffer< CSScalar >	_kernel
	The filter kernel of order _order. More...

Buffer< CSScalar >	_ring
	A ring buffer of past values. More...

Buffer< CScalar >	_buffer
	The output buffer. More...

Protected Attributes inherited from sdr::Source
Config	_config
	Holds the source configuration, this can be updated by calling `setConfig`. More...

std::map< SinkBase *, bool >	_sinks
	The connected sinks. More...

std::list< DelegateInterface * >	_eos
	The connected EOS singal handlers. More...

Protected Attributes inherited from sdr::FreqShiftBase< Scalar >
double	_freq_shift
	The current frequency shift. More...

double	_Fs
	The current sample rate. More...

size_t	_lut_inc
	The LUT increment. More...

size_t	_lut_count
	The LUT index counter. More...

Buffer< CSScalar >	_lut
	The LUT. More...

Additional Inherited Members
Static Protected Attributes inherited from sdr::FreqShiftBase< Scalar >
static const size_t	_lut_size = 128
	The size of the LUT. More...

Detailed Description

template<class Scalar>
class sdr::IQBaseBand< Scalar >

This class performs several operations on the complex (integral) input stream, it first filters out some part of the input stream using a FIR band pass (band pass is centerred around Ff with width width) then shifts the center frequency Fc to 0 and finally sub-samples the resulting stream.

This node can be used to select a portion of the input spectrum and for the reduction of the stream rate, allowing for some more expensive operations to be performed on the output stream.

Member Typedef Documentation

template<class Scalar >

typedef std::complex<Scalar> sdr::IQBaseBand< Scalar >::CScalar

The complex type of the input stream.

template<class Scalar >

typedef std::complex<SScalar> sdr::IQBaseBand< Scalar >::CSScalar

Complex SScalar type.

template<class Scalar >

typedef int32_t sdr::IQBaseBand< Scalar >::SScalar

The (real) computation scalar type (super scalar), the computations are performed with this scalar type.

Constructor & Destructor Documentation

template<class Scalar >

sdr::IQBaseBand< Scalar >::IQBaseBand	(	double	Fc,
		double	width,
		size_t	order,
		size_t	sub_sample,
		double	oFs = `0.0`
	)

inline

Constructor, the filter center frequency Ff equals the given center frequency Fc.

template<class Scalar >

sdr::IQBaseBand< Scalar >::IQBaseBand	(	double	Fc,
		double	Ff,
		double	width,
		size_t	order,
		size_t	sub_sample,
		double	oFs = `0.0`
	)

inline

Constructor.

template<class Scalar >

virtual sdr::IQBaseBand< Scalar >::~IQBaseBand ( )

inlinevirtual

Destructor.

Member Function Documentation

template<class Scalar >

CSScalar sdr::IQBaseBand< Scalar >::_filter_ring ( ) const

inlineprotected

Applies the filter on the data stored in the ring buffer.

template<class Scalar >

void sdr::IQBaseBand< Scalar >::_process	(	const Buffer< CScalar > &	in,
		const Buffer< CScalar > &	out
	)

inlineprotected

Performs the base-band selection, frequency shift and sub-sampling.

Stores the results into out. The input and output buffer may overlapp.

template<class Scalar >

void sdr::IQBaseBand< Scalar >::_reconfigure ( )

inlineprotected

Reconfigures the node.

template<class Scalar >

void sdr::IQBaseBand< Scalar >::_update_filter_kernel ( )

inlineprotected

Updates the band-pass filter kernel.

template<class Scalar >

double sdr::IQBaseBand< Scalar >::centerFrequency ( ) const

inline

Returns the center frequency.

template<class Scalar >

virtual void sdr::IQBaseBand< Scalar >::config ( const Config & src_cfg )

inlinevirtual

Configures the BaseBand node.

Implements sdr::SinkBase.

template<class Scalar >

double sdr::IQBaseBand< Scalar >::filterFrequency ( ) const

inline

Returns the filter frequency.

template<class Scalar >

double sdr::IQBaseBand< Scalar >::filterWidth ( ) const

inline

Returns the filter width.

template<class Scalar >

size_t sdr::IQBaseBand< Scalar >::order ( ) const

inline

Returns the order of the band-pass filter.

template<class Scalar >

virtual void sdr::IQBaseBand< Scalar >::process	(	const Buffer< std::complex< Scalar > > &	buffer,
		bool	allow_overwrite
	)

inlinevirtual

Processes the given buffer.

Implements sdr::Sink< std::complex< Scalar > >.

template<class Scalar >

void sdr::IQBaseBand< Scalar >::setCenterFrequency ( double Fc )

inline

Resets the center frequency.

template<class Scalar >

void sdr::IQBaseBand< Scalar >::setFilterFrequency ( double Ff )

inline

(Re-) Sets the filter frequency.

template<class Scalar >

void sdr::IQBaseBand< Scalar >::setFilterWidth ( double width )

inline

Sets the filter width.

template<class Scalar >

void sdr::IQBaseBand< Scalar >::setOrder ( size_t o )

inline

(Re-) Sets the filter order.

template<class Scalar >

void sdr::IQBaseBand< Scalar >::setOutputSampleRate ( double Fs )

inline

Resets the output sample rate.

The sub-sampling will be adjusted accordingly. Please note the the resulting output sample rate will be rounded up to be an integral fraction of the input sample rate.

template<class Scalar >

void sdr::IQBaseBand< Scalar >::setSubsample ( size_t sub_sample )

inline

Resets the sub sampling.

Please note that the Queue needs to be stopped before calling this function!

template<class Scalar >

size_t sdr::IQBaseBand< Scalar >::subSample ( ) const

inline

Returns the sub sampling.

Member Data Documentation

template<class Scalar >

Buffer<CScalar> sdr::IQBaseBand< Scalar >::_buffer

protected

The output buffer.

template<class Scalar >

int32_t sdr::IQBaseBand< Scalar >::_Fc

protected

The frequency shift of the base band.

The filter result will be shifted by -_Fc.

template<class Scalar >

int32_t sdr::IQBaseBand< Scalar >::_Ff

protected

The center frequency of the base band.

template<class Scalar >

int32_t sdr::IQBaseBand< Scalar >::_Fs

protected

The input sample rate.

template<class Scalar >

Buffer<CSScalar> sdr::IQBaseBand< Scalar >::_kernel

protected

The filter kernel of order _order.

template<class Scalar >

CSScalar sdr::IQBaseBand< Scalar >::_last

protected

Holds the current sum of the last _sample_count samples.

template<class Scalar >

double sdr::IQBaseBand< Scalar >::_oFs

protected

Holds the desired output sample rate, _sub_sample will be adjusted accordingly.

template<class Scalar >

size_t sdr::IQBaseBand< Scalar >::_order

protected

The order of the filter.

Must be greater that 0.

template<class Scalar >

Buffer<CSScalar> sdr::IQBaseBand< Scalar >::_ring

protected

A ring buffer of past values.

The band-pass filtering is performed on this buffer.

template<class Scalar >

size_t sdr::IQBaseBand< Scalar >::_ring_offset

protected

The current index of the ring buffer.

template<class Scalar >

size_t sdr::IQBaseBand< Scalar >::_sample_count

protected

Holds the current number of samples averaged.

template<class Scalar >

size_t sdr::IQBaseBand< Scalar >::_sourceBs

protected

Buffer size of the source.

template<class Scalar >

size_t sdr::IQBaseBand< Scalar >::_sub_sample

protected

The number of sample averages for the sub sampling.

_sub_sample==1 means no subsampling.

template<class Scalar >

int32_t sdr::IQBaseBand< Scalar >::_width

protected

The filter width.

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

/Users/hannes/Uni/Elektronik/sdr/libsdr/src/baseband.hh

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

template<class Scalar> class sdr::IQBaseBand< Scalar >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class Scalar>
class sdr::IQBaseBand< Scalar >