Adaptive FIR filter with gr_complex input, gr_complex output and gr_complex tapsThis is a base class to implement an adaptive FIR filter. Generally, another block will inherit from this one to build a new type of adaptive filter such as an equalizer. More...

#include <adaptive_fir_ccc.h>

Inheritance diagram for gr::filter::adaptive_fir_ccc:

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Public Types
typedef boost::shared_ptr < adaptive_fir_ccc >	sptr

Public Member Functions
virtual void	set_taps (const std::vector< gr_complex > &taps)=0
virtual std::vector< gr_complex >	taps () const =0
Public Member Functions inherited from gr_sync_decimator
unsigned	decimation () const
void	set_decimation (unsigned decimation)
void	forecast (int noutput_items, gr_vector_int &ninput_items_required)
	Estimate input requirements given output request.
int	general_work (int noutput_items, gr_vector_int &ninput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
	compute output items from input items
int	fixed_rate_ninput_to_noutput (int ninput)
	Given ninput samples, return number of output samples that will be produced. N.B. this is only defined if fixed_rate returns true. Generally speaking, you don't need to override this.
int	fixed_rate_noutput_to_ninput (int noutput)
	Given noutput samples, return number of input samples required to produce noutput. N.B. this is only defined if fixed_rate returns true. Generally speaking, you don't need to override this.
Public Member Functions inherited from gr_sync_block
virtual int	work (int noutput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)=0
	just like gr_block::general_work, only this arranges to call consume_each for you
Public Member Functions inherited from gr_block
virtual	~gr_block ()
unsigned	history () const
void	set_history (unsigned history)
bool	fixed_rate () const
	Return true if this block has a fixed input to output rate.
virtual bool	start ()
	Called to enable drivers, etc for i/o devices.
virtual bool	stop ()
	Called to disable drivers, etc for i/o devices.
void	set_output_multiple (int multiple)
	Constrain the noutput_items argument passed to forecast and general_work.
int	output_multiple () const
bool	output_multiple_set () const
void	set_alignment (int multiple)
	Constrains buffers to work on a set item alignment (for SIMD)
int	alignment () const
void	set_unaligned (int na)
int	unaligned () const
void	set_is_unaligned (bool u)
bool	is_unaligned () const
void	consume (int which_input, int how_many_items)
	Tell the scheduler `how_many_items` of input stream `which_input` were consumed.
void	consume_each (int how_many_items)
	Tell the scheduler `how_many_items` were consumed on each input stream.
void	produce (int which_output, int how_many_items)
	Tell the scheduler `how_many_items` were produced on output stream `which_output`.
void	set_relative_rate (double relative_rate)
	Set the approximate output rate / input rate.
double	relative_rate () const
	return the approximate output rate / input rate
uint64_t	nitems_read (unsigned int which_input)
	Return the number of items read on input stream which_input.
uint64_t	nitems_written (unsigned int which_output)
	Return the number of items written on output stream which_output.
tag_propagation_policy_t	tag_propagation_policy ()
	Asks for the policy used by the scheduler to moved tags downstream.
void	set_tag_propagation_policy (tag_propagation_policy_t p)
	Set the policy by the scheduler to determine how tags are moved downstream.
gr_block_detail_sptr	detail () const
void	set_detail (gr_block_detail_sptr detail)
Public Member Functions inherited from gr_basic_block
virtual	~gr_basic_block ()
long	unique_id () const
std::string	name () const
gr_io_signature_sptr	input_signature () const
gr_io_signature_sptr	output_signature () const
gr_basic_block_sptr	to_basic_block ()
virtual bool	check_topology (int ninputs, int noutputs)
	Confirm that ninputs and noutputs is an acceptable combination.
template<typename T >
void	set_msg_handler (T msg_handler)
	Set the callback that is fired when messages are available.
Public Member Functions inherited from gr_msg_accepter
	gr_msg_accepter ()
	~gr_msg_accepter ()
void	post (pmt::pmt_t msg)
	send `msg` to `msg_accepter`
Public Member Functions inherited from gruel::msg_accepter
	msg_accepter ()
virtual	~msg_accepter ()

Static Public Member Functions
static sptr	make (const char *name, int decimation, const std::vector< gr_complex > &taps)
	Adaptive FIR filter with gr_complex input, gr_complex output and gr_complex taps.

Additional Inherited Members
Protected Types inherited from gr_basic_block
enum	vcolor { WHITE, GREY, BLACK }
Protected Member Functions inherited from gr_sync_decimator
	gr_sync_decimator (void)
	gr_sync_decimator (const std::string &name, gr_io_signature_sptr input_signature, gr_io_signature_sptr output_signature, unsigned decimation)
Protected Attributes inherited from gr_basic_block
std::string	d_name
gr_io_signature_sptr	d_input_signature
gr_io_signature_sptr	d_output_signature
long	d_unique_id
vcolor	d_color

Detailed Description

Adaptive FIR filter with gr_complex input, gr_complex output and gr_complex taps

This is a base class to implement an adaptive FIR filter. Generally, another block will inherit from this one to build a new type of adaptive filter such as an equalizer.

This class implements two functions that are designed to be overloaded by the child class: error(gr_complex out) and update_tap(gr_complex tap, gr_complex in).

The error() function calculates the error value that will be used to adjust the taps. The update_tap function then uses the error and the input signal value to update a particular tap. Typically, the error is calculated for a given output and then this is used in a loop to update all of the filter taps in a loop:

d_error = error(sum);
for(k = 0; k < l; k++) {
  update_tap(d_taps[ntaps-k-1], in[i+k]);
}

See digital::cma_equalizer_cc and digital::lms_dd_equalizer_cc for example usage.

Member Typedef Documentation

typedef boost::shared_ptr<adaptive_fir_ccc> gr::filter::adaptive_fir_ccc::sptr

Member Function Documentation

static sptr gr::filter::adaptive_fir_ccc::make	(	const char *	name,
		int	decimation,
		const std::vector< gr_complex > &	taps
	)

static

Adaptive FIR filter with gr_complex input, gr_complex output and gr_complex taps.

Parameters

name	Provides a name to identify this type of algorithm
decimation	(interger) decimation rate of the filter
taps	(complex) filter taps

virtual void gr::filter::adaptive_fir_ccc::set_taps ( const std::vector< gr_complex > & taps )

pure virtual

Implemented in gr::filter::adaptive_fir_ccc_impl.

virtual std::vector<gr_complex> gr::filter::adaptive_fir_ccc::taps ( ) const

pure virtual

Implemented in gr::filter::adaptive_fir_ccc_impl.

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

adaptive_fir_ccc.h

Public Types

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Member Typedef Documentation

Member Function Documentation