This class performs several operations on the real input stream, It first filters out some part of the input stream using a FIR band pass filter then shifts the center frequency to 0 and finally sub-samples the resulting stream such that the selected base-band is well represented. More...

#include <baseband.hh>

Inheritance diagram for sdr::BaseBand< Scalar >:

Public Types
typedef FreqShiftBase< Scalar >::CScalar	CScalar
	The complex input scalar. More...

typedef FreqShiftBase< Scalar >::SScalar	SScalar
	The real super scalar. More...

typedef FreqShiftBase< Scalar >::CSScalar	CSScalar
	The complex super scalar. 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
	BaseBand (double Fc, double width, size_t order, size_t sub_sample)
	Constructs a new BaseBand instance. More...

	BaseBand (double Fc, double Ff, double width, size_t order, size_t sub_sample)
	Constructs a new BaseBand instance. More...

virtual	~BaseBand ()
	Destructor. More...

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

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

virtual void	process (const Buffer< Scalar > &buffer, bool allow_overwrite)
	Processes the input buffer. More...

Public Member Functions inherited from sdr::Sink< 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...

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	_process (const Buffer< Scalar > &in, const Buffer< CScalar > &out)
	Performs the actual procssing. More...

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

void	_update_filter_kernel ()
	Calculates or updates the 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
double	_Ff
	The center frequency of the band pass filter. More...

double	_width
	The width of the band pass filter. More...

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

size_t	_sub_sample
	The number of averages taken for subsampling. More...

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

size_t	_sample_count
	The current number of averages. More...

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

bool	_shift_freq
	If true, `Fc!=0`. More...

Buffer< CSScalar >	_lut
	$\exp(i\phi)$ look-up table

size_t	_lut_inc
	The LUT index increment per (1<<4) samples. More...

size_t	_lut_count
	The current LUT index times (1<<4). More...

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

Buffer< SScalar >	_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...

Static Protected Attributes
static const size_t	_lut_size =128
	Size of the look-up table. More...

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::BaseBand< Scalar >

This class performs several operations on the real input stream, It first filters out some part of the input stream using a FIR band pass filter then shifts the center frequency to 0 and finally sub-samples the resulting stream such that the selected base-band is well represented.

Member Typedef Documentation

template<class Scalar >

typedef FreqShiftBase<Scalar>::CScalar sdr::BaseBand< Scalar >::CScalar

The complex input scalar.

template<class Scalar >

typedef FreqShiftBase<Scalar>::CSScalar sdr::BaseBand< Scalar >::CSScalar

The complex super scalar.

template<class Scalar >

typedef FreqShiftBase<Scalar>::SScalar sdr::BaseBand< Scalar >::SScalar

The real super scalar.

Constructor & Destructor Documentation

template<class Scalar >

sdr::BaseBand< Scalar >::BaseBand	(	double	Fc,
		double	width,
		size_t	order,
		size_t	sub_sample
	)

inline

Constructs a new BaseBand instance.

Parameters

Fc	Specifies the center frequency of the base band. The resulting signal will be shifted down by this frequency.
width	Specifies the with of the band pass filter.
order	Specifies the order of the FIR band pass filter.
sub_sample	Specifies the sub-sampling of the resulting singnal.

template<class Scalar >

sdr::BaseBand< Scalar >::BaseBand	(	double	Fc,
		double	Ff,
		double	width,
		size_t	order,
		size_t	sub_sample
	)

inline

Constructs a new BaseBand instance.

Parameters

Fc	Specifies the frequency of the base band. The resulting signal will be shifted down by this frequency.
Ff	Specifies the center frequency of the band pass filter.
width	Specifies the with of the band pass filter.
order	Specifies the order of the FIR band pass filter.
sub_sample	Specifies the sub-sampling of the resulting singnal.

template<class Scalar >

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

inlinevirtual

Destructor.

Member Function Documentation

template<class Scalar >

CSScalar sdr::BaseBand< Scalar >::_filter_ring ( )

inlineprotected

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

template<class Scalar >

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

inlineprotected

Performs the actual procssing.

First, the bandpass filter is applied, then the filtered signal is shifted and finally the signal gets averaged over _sub_sample samples, implementing the averaging sub-sampling.

template<class Scalar >

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

inlineprotected

Calculates or updates the filter kernel.

template<class Scalar >

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

inlinevirtual

Configures the base band node.

Implements the Sink interface.

Implements sdr::SinkBase.

template<class Scalar >

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

inlinevirtual

Processes the input buffer.

Implements the Sink interface.

Implements sdr::Sink< Scalar >.

template<class Scalar >

virtual void sdr::BaseBand< Scalar >::setSampleRate ( double Fs )

inlinevirtual

Sets the sample rate and updates the LUT.

Bug:: Also signal config change of the sourcce by setConfig()!

Reimplemented from sdr::FreqShiftBase< Scalar >.

Member Data Documentation

template<class Scalar >

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

protected

The output buffer.

template<class Scalar >

double sdr::BaseBand< Scalar >::_Ff

protected

The center frequency of the band pass filter.

template<class Scalar >

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

protected

The filter kernel of order _order.

template<class Scalar >

CSScalar sdr::BaseBand< Scalar >::_last

protected

The current sum of the last _sample_count samples.

template<class Scalar >

size_t sdr::BaseBand< Scalar >::_lut_count

protected

The current LUT index times (1<<4).

template<class Scalar >

size_t sdr::BaseBand< Scalar >::_lut_inc

protected

The LUT index increment per (1<<4) samples.

template<class Scalar >

const size_t sdr::BaseBand< Scalar >::_lut_size =128

staticprotected

Size of the look-up table.

template<class Scalar >

size_t sdr::BaseBand< Scalar >::_order

protected

The order of the band pass filter.

template<class Scalar >

Buffer<SScalar> sdr::BaseBand< Scalar >::_ring

protected

A ring buffer of past values.

template<class Scalar >

size_t sdr::BaseBand< Scalar >::_ring_offset

protected

The current index of the ring buffer.

template<class Scalar >

size_t sdr::BaseBand< Scalar >::_sample_count

protected

The current number of averages.

template<class Scalar >

bool sdr::BaseBand< Scalar >::_shift_freq

protected

If true, Fc!=0.

template<class Scalar >

size_t sdr::BaseBand< Scalar >::_sub_sample

protected

The number of averages taken for subsampling.

template<class Scalar >

double sdr::BaseBand< Scalar >::_width

protected

The width of the band pass filter.

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

Static Protected Attributes

Detailed Description

template<class Scalar> class sdr::BaseBand< Scalar >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class Scalar>
class sdr::BaseBand< Scalar >