SPUC::LFSR Class Reference

Binary Linear Feedback Shift Register (LFSR). More...

#include <sequence.h>

List of all members.

Public Member Functions
	LFSR (void)
	Constructor.
	LFSR (const bvec &connections)
	Input connect_polynomial=1+g1*D+g2*D^2+...+gr*D^r in bvec format [g0,g1,...,gr].
	LFSR (const ivec &connections)
	Input connect_polynomial=1+g1*D+g2*D^2+...+gr*D^r in octal format.
void	set_connections (const bvec &connections)
	Input connect_polynomial=1+g1*D+g2*D^2+...+gr*D^r in bvec format [g0,g1,...,gr].
void	set_connections (const ivec &connections)
	Input connect_polynomial=1+g1*D+g2*D^2+...+gr*D^r in octal format.
void	set_state (const bvec &state)
	Set state (contents in the shift registers) in bvec format.
void	set_state (const ivec &state)
	Set state (contents in the shift registers) in octal format.
bin	shift (void)
	Shift one step and output binary symbol.
bvec	shift (int no_shifts)
	Shift no_shifts steps and output bvec.
int	get_length (void)
	Return length of shift register.
bvec	get_state (void)
	Returns the state of the shift register.

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Detailed Description

Binary Linear Feedback Shift Register (LFSR).

• The LFSR is on Fibonacci form (see e.g. page 104 in Peterson, Ziemer, and Borth "Introduction to Spread Spctrum communications", Prentice-Hall, 1995.)
• If the connect_polynomial=1+g1*D+g2*D^2+...+gr*D^r is a primitive polynomial a Maximum Length Sequence (m-seq.) of length N=2^r -1 is constructed. Use an arbitrary state not equal to zero, to get a phase of the m-sequence.
• For a table of primtive polynomials see e.g. page 117 in the reference above or a suitable book on coding.

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Constructor & Destructor Documentation

SPUC::LFSR::LFSR (  void   )  [inline]

Constructor.

LFSR::LFSR (  const bvec &  connections  )

Input connect_polynomial=1+g1*D+g2*D^2+...+gr*D^r in bvec format [g0,g1,...,gr].

LFSR::LFSR (  const ivec &  connections  )

Input connect_polynomial=1+g1*D+g2*D^2+...+gr*D^r in octal format.

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Member Function Documentation

int SPUC::LFSR::get_length (  void   )  [inline]

Return length of shift register.

bvec SPUC::LFSR::get_state (  void   )  [inline]

Returns the state of the shift register.

void LFSR::set_connections (  const ivec &  connections  )

Input connect_polynomial=1+g1*D+g2*D^2+...+gr*D^r in octal format.

void LFSR::set_connections (  const bvec &  connections  )

Input connect_polynomial=1+g1*D+g2*D^2+...+gr*D^r in bvec format [g0,g1,...,gr].

void LFSR::set_state (  const ivec &  state  )

Set state (contents in the shift registers) in octal format.

void LFSR::set_state (  const bvec &  state  )

Set state (contents in the shift registers) in bvec format.

bvec LFSR::shift (  int  no_shifts  )

Shift no_shifts steps and output bvec.

bin SPUC::LFSR::shift (  void   )  [inline]

Shift one step and output binary symbol.

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

• comm/sequence.h
• comm/sequence.cpp

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