SPUC::farrow< Numeric > Class Template Reference
[SPUC templates, FIR filters, Interpolation filters]

Template Class for Farrow implementation of a ploynomial interpolation using a FIR filter. More...

#include <farrow.h>

Collaboration diagram for SPUC::farrow< Numeric >:

[legend]List of all members.

Public Member Functions
Numeric	out ()
	Get current output.
Numeric	check (long i)
	Clock in new sample & compute current output.
	farrow (char order)
	Need to cover different orders!
void	reset (void)
	reset
	~farrow (void)
void	input (Numeric in)
	Only input new sample.
Numeric	update (Numeric in, float_type offset)
Numeric	fir (float_type offset)
	Calculate output for current coefficients. Offset is between 0 and 1.
Numeric	rephase (float_type offset)
	Rephase => recalculate coefficients and output for new offset (for upsampling).
void	calculate_coeff2 (void)
	Calculate coefficients for linear (not tested).
void	calculate_coeff3 (void)
	Calculate coefficients for square.
void	calculate_coeff3a (void)
	Calculate coefficients for parabolic.
void	calculate_coeff4 (void)
	Calculate coefficients for 4th order.
Public Attributes
long	num_taps
smart_array< Numeric >	coeff
Protected Attributes
smart_array< Numeric >	z
Numeric	output

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Detailed Description

template<class Numeric>
class SPUC::farrow< Numeric >

Template Class for Farrow implementation of a ploynomial interpolation using a FIR filter.

Farrow implementation of a polynomial interpolation This covers 3 (orders) cases of interpolation 1. Linear (not efficient using this method) 2. Piecewise-Parabolic 3. Cubic Although derived from the Lagrange coefficients the multiplication factor have been simplified to allow simple VLSI implementations. see Interpolation in Digital Modem - Part II, IEEE Trans. on Comms. June 1993.

Author:

Tony Kirke

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Constructor & Destructor Documentation

template<class Numeric>

SPUC::farrow< Numeric >::farrow

(

char

order

)

[inline]

Need to cover different orders!

template<class Numeric>

SPUC::farrow< Numeric >::~farrow

(

void

)

[inline]

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Member Function Documentation

template<class Numeric>

void SPUC::farrow< Numeric >::calculate_coeff2

(

void

)

[inline]

Calculate coefficients for linear (not tested).

template<class Numeric>

void SPUC::farrow< Numeric >::calculate_coeff3

(

void

)

[inline]

Calculate coefficients for square.

template<class Numeric>

void SPUC::farrow< Numeric >::calculate_coeff3a

(

void

)

[inline]

Calculate coefficients for parabolic.

template<class Numeric>

void SPUC::farrow< Numeric >::calculate_coeff4

(

void

)

[inline]

Calculate coefficients for 4th order.

template<class Numeric>

Numeric SPUC::farrow< Numeric >::check

(

long

i

)

[inline]

Clock in new sample & compute current output.

template<class Numeric>

Numeric SPUC::farrow< Numeric >::fir

(

float_type

offset

)

[inline]

Calculate output for current coefficients. Offset is between 0 and 1.

template<class Numeric>

void SPUC::farrow< Numeric >::input

(

Numeric

in

)

[inline]

Only input new sample.

template<class Numeric>

Numeric SPUC::farrow< Numeric >::out

(

)

[inline]

Get current output.

template<class Numeric>

Numeric SPUC::farrow< Numeric >::rephase

(

float_type

offset

)

[inline]

Rephase => recalculate coefficients and output for new offset (for upsampling).

template<class Numeric>

void SPUC::farrow< Numeric >::reset

(

void

)

[inline]

reset

template<class Numeric>

Numeric SPUC::farrow< Numeric >::update	(	Numeric	in,
		float_type	offset
	)			[inline]

: Update => Clock in new input sample, recalculate coefficients and determine output

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Member Data Documentation

template<class Numeric>

smart_array<Numeric> SPUC::farrow< Numeric >::coeff

template<class Numeric>

long SPUC::farrow< Numeric >::num_taps

template<class Numeric>

Numeric SPUC::farrow< Numeric >::output [protected]

template<class Numeric>

smart_array<Numeric> SPUC::farrow< Numeric >::z [protected]

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

• farrow.h

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