gr::digital::ofdm_equalizer_static Class Reference

Very simple static equalizer for OFDM. More...

#include <gnuradio/digital/ofdm_equalizer_static.h>

Public Types
typedef boost::shared_ptr< ofdm_equalizer_static >	sptr
Public Types inherited from gr::digital::ofdm_equalizer_1d_pilots
typedef boost::shared_ptr< ofdm_equalizer_1d_pilots >	sptr
Public Types inherited from gr::digital::ofdm_equalizer_base
typedef boost::shared_ptr< ofdm_equalizer_base >	sptr

Public Member Functions
	ofdm_equalizer_static (int fft_len, const std::vector< std::vector< int > > &occupied_carriers=std::vector< std::vector< int > >(), const std::vector< std::vector< int > > &pilot_carriers=std::vector< std::vector< int > >(), const std::vector< std::vector< gr_complex > > &pilot_symbols=std::vector< std::vector< gr_complex > >(), int symbols_skipped=0, bool input_is_shifted=true)
	~ofdm_equalizer_static ()
void	equalize (gr_complex *frame, int n_sym, const std::vector< gr_complex > &initial_taps=std::vector< gr_complex >(), const std::vector< tag_t > &tags=std::vector< tag_t >())
	Divide the input signal with the current channel state. More...
Public Member Functions inherited from gr::digital::ofdm_equalizer_1d_pilots
	ofdm_equalizer_1d_pilots (int fft_len, const std::vector< std::vector< int > > &occupied_carriers, const std::vector< std::vector< int > > &pilot_carriers, const std::vector< std::vector< gr_complex > > &pilot_symbols, int symbols_skipped, bool input_is_shifted)
	~ofdm_equalizer_1d_pilots ()
void	reset ()
	Reset the channel information state knowledge. More...
void	get_channel_state (std::vector< gr_complex > &taps)
	Return the current channel state. More...
Public Member Functions inherited from gr::digital::ofdm_equalizer_base
	ofdm_equalizer_base (int fft_len)
virtual	~ofdm_equalizer_base ()
int	fft_len ()
sptr	base ()

Static Public Member Functions
static sptr	make (int fft_len, const std::vector< std::vector< int > > &occupied_carriers=std::vector< std::vector< int > >(), const std::vector< std::vector< int > > &pilot_carriers=std::vector< std::vector< int > >(), const std::vector< std::vector< gr_complex > > &pilot_symbols=std::vector< std::vector< gr_complex > >(), int symbols_skipped=0, bool input_is_shifted=true)

Additional Inherited Members
Protected Attributes inherited from gr::digital::ofdm_equalizer_1d_pilots
std::vector< bool >	d_occupied_carriers
	If d_occupied_carriers[k][l] is true, symbol k, carrier l is carrying data. More...
std::vector< std::vector< bool > >	d_pilot_carriers
	If d_pilot_carriers[k][l] is true, symbol k, carrier l is carrying data. More...
std::vector< std::vector< gr_complex > >	d_pilot_symbols
	If d_pilot_carriers[k][l] is true, d_pilot_symbols[k][l] is its tx'd value. More...
int	d_symbols_skipped
	In case the frame doesn't begin with OFDM symbol 0, this is the index of the first symbol. More...
int	d_pilot_carr_set
	The current position in the set of pilot symbols. More...
std::vector< gr_complex >	d_channel_state
	Vector of length d_fft_len saving the current channel state (on the occupied carriers) More...
Protected Attributes inherited from gr::digital::ofdm_equalizer_base
int	d_fft_len

Detailed Description

Very simple static equalizer for OFDM.

This is an extremely simple equalizer. It will only work for high-SNR, very, very slowly changing channels.

It simply divides the signal with the currently known channel state. Whenever a pilot symbol comes around, it updates the channel state on that particular carrier by dividing the received symbol with the known pilot symbol.

Member Typedef Documentation

typedef boost::shared_ptr<ofdm_equalizer_static> gr::digital::ofdm_equalizer_static::sptr

Constructor & Destructor Documentation

gr::digital::ofdm_equalizer_static::ofdm_equalizer_static	(	int	fft_len,
		const std::vector< std::vector< int > > &	occupied_carriers = std::vector< std::vector< int > >(),
		const std::vector< std::vector< int > > &	pilot_carriers = std::vector< std::vector< int > >(),
		const std::vector< std::vector< gr_complex > > &	pilot_symbols = std::vector< std::vector< gr_complex > >(),
		int	symbols_skipped = 0,
		bool	input_is_shifted = true
	)

gr::digital::ofdm_equalizer_static::~ofdm_equalizer_static

(

)

Member Function Documentation

void gr::digital::ofdm_equalizer_static::equalize ( gr_complex *  frame, int  n_sym, const std::vector< gr_complex > &  initial_taps = std::vector< gr_complex >(), const std::vector< tag_t > &  tags = std::vector< tag_t >()  )

virtual

Divide the input signal with the current channel state.

Does the following (and nothing else):

• Divide every OFDM symbol with the current channel state
• If a pilot symbol is found, re-set the channel state by dividing the received symbol with the known pilot symbol

Implements gr::digital::ofdm_equalizer_base.

static sptr gr::digital::ofdm_equalizer_static::make ( int  fft_len, const std::vector< std::vector< int > > &  occupied_carriers = std::vector< std::vector< int > >(), const std::vector< std::vector< int > > &  pilot_carriers = std::vector< std::vector< int > >(), const std::vector< std::vector< gr_complex > > &  pilot_symbols = std::vector< std::vector< gr_complex > >(), int  symbols_skipped = 0, bool  input_is_shifted = true  )

static

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

• ofdm_equalizer_static.h