gr::baz::additive_scrambler_bb Class Reference

Scramble an input stream using an LFSR. More...

#include <baz_additive_scrambler_bb.h>

Inheritance diagram for gr::baz::additive_scrambler_bb:

Public Types
typedef boost::shared_ptr< additive_scrambler_bb >	sptr

Public Member Functions
virtual int	mask () const =0
virtual int	seed () const =0
virtual int	len () const =0
virtual int	count () const =0
virtual int	bits_per_byte ()=0

Static Public Member Functions
static sptr	make (int mask, int seed, int len, int count=0, int bits_per_byte=1, const std::string &reset_tag_key="")
	Create additive scrambler.

Detailed Description

Scramble an input stream using an LFSR.

This block scrambles up to 8 bits per byte of the input data stream, starting at the LSB.

The scrambler works by XORing the incoming bit stream by the output of the LFSR. Optionally, after count bits have been processed, the shift register is reset to the seed value. This allows processing fixed length vectors of samples.

Alternatively, the LFSR can be reset using a reset tag to scramble variable length vectors. However, it cannot be reset between bytes.

For details on configuring the LFSR, see gr::digital::lfsr.

Member Typedef Documentation

sptr

typedef boost::shared_ptr<additive_scrambler_bb> gr::baz::additive_scrambler_bb::sptr

Member Function Documentation

bits_per_byte()

virtual int gr::baz::additive_scrambler_bb::bits_per_byte ( )

pure virtual

Referenced by make().

count()

virtual int gr::baz::additive_scrambler_bb::count ( ) const

pure virtual

Referenced by make().

len()

virtual int gr::baz::additive_scrambler_bb::len ( ) const

pure virtual

Referenced by make().

make()

sptr gr::baz::additive_scrambler_bb::make ( int mask, int seed, int len, int count = 0, int bits_per_byte = 1, const std::string & reset_tag_key = "" )

static

Create additive scrambler.

Parameters

mask	Polynomial mask for LFSR
seed	Initial shift register contents
len	Shift register length
count	Number of bytes after which shift register is reset, 0=never
bits_per_byte	Number of bits per byte
reset_tag_key	When a tag with this key is detected, the shift register is reset (when this is set, count is ignored!)

References bits_per_byte(), count(), len(), mask(), and seed().

mask()

virtual int gr::baz::additive_scrambler_bb::mask ( ) const

pure virtual

Referenced by make().

seed()

virtual int gr::baz::additive_scrambler_bb::seed ( ) const

pure virtual

Referenced by make().

---

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

• baz_additive_scrambler_bb.h