Configuration of the Olivia and Contestia modems (OliviaEncoder, OliviaDecoder): MFSK with 2 to 256 tones and a strong forward error correction (Walsh-Hadamard codes over blocks of 64 or 32 symbols), as designed by Pawel Jalocha and implemented by fldigi. More...

#include <Olivia.h>

Inheritance diagram for tinymodem::OliviaConfig:

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Collaboration diagram for tinymodem::OliviaConfig:

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Public Member Functions
	OliviaConfig ()
bool	setMode (const char *mode)
int	bitsPerSymbol () const
	number of bits per symbol (log2 of the tones)
int	symbolLen () const
	FFT length (window of a symbol) in samples at 8000 Hz.
int	symbolSepar () const
	distance of two symbols in samples at 8000 Hz
int	symbolsPerBlock () const
	symbols per FEC block: 64 for Olivia, 32 for Contestia
int	bitsPerCharacter () const
	bits per character: 7 for Olivia, 6 for Contestia
int	firstCarrier () const
	lowest tone as FFT bin (like fldigi)
float	toneFreq (int tone) const
	frequency of a tone in Hz
float	symbolRate () const
	symbols per second
float	charRate () const
	characters per second
bool	isValid () const
	Checks the configuration: returns false (and logs the reason) if invalid.

Static Public Member Functions
static bool	isMode (const char *mode)
	true if the mode is an Olivia or Contestia mode

Public Attributes
int	tones = 32
	number of tones (power of 2: 2 - 256)
int	bandwidth = 1000
	bandwidth in Hz: 125, 250, 500, 1000 or 2000
float	center_freq = 1500.0f
	center frequency in Hz
bool	contestia = false
	Contestia instead of Olivia.
float	volume = 1.0f
	transmit amplitude (0.0 - 1.0)
bool	start_tones = true
	transmitter: send the start and stop tones (like fldigi)
int	sync_margin = 8
int	sync_integration = 4
	receiver: integration period of the synchronizer in FEC blocks
float	sync_threshold = 3.0f
	receiver: minimum signal to noise ratio of the synchronizer
bool	rx_one = false
	receiver: stop after the first transmission
uint8_t	channel = 0
	receiver: input channel which is used for the decoding
float	rx_noise = 0.0f
	receiver: (testing only) amplitude of added uniform noise

Static Public Attributes
static constexpr float	BASE_RATE = 8000.0f
	internal sample rate which defines the signal
static constexpr int	MAX_SYMBOL_LEN = 2048
	largest supported FFT length

Static Protected Member Functions
static bool	parseMode (const char *mode, int &tones, int &bandwidth, bool &contestia)
static bool	startsWith (const char str, const char prefix)

Detailed Description

Configuration of the Olivia and Contestia modems (OliviaEncoder, OliviaDecoder): MFSK with 2 to 256 tones and a strong forward error correction (Walsh-Hadamard codes over blocks of 64 or 32 symbols), as designed by Pawel Jalocha and implemented by fldigi.

setMode() selects "olivia-T-B" or "contestia-T-B" with T tones and a bandwidth B of 125, 250, 500, 1000 or 2000 Hz (also written as 1k or 2k), e.g. "olivia-8-250" or "olivia-32-1000". "olivia" is "olivia-32-1000", "contestia" is "contestia-8-250". Olivia sends 7 bit characters (and 8 bit characters escaped with 127 like fldigi), Contestia sends upper case text with 6 bit characters at twice the speed: a line break is sent as '\r' (which fldigi shows as new line), '\r' is ignored.

The signal is defined at 8000 Hz: other sample rates are converted.

Copyright: GPLv3

Constructor & Destructor Documentation

◆ OliviaConfig()

tinymodem::OliviaConfig::OliviaConfig ( )

inline

Member Function Documentation

◆ bitsPerCharacter()

int tinymodem::OliviaConfig::bitsPerCharacter ( ) const

inline

bits per character: 7 for Olivia, 6 for Contestia

◆ bitsPerSymbol()

int tinymodem::OliviaConfig::bitsPerSymbol ( ) const

inline

number of bits per symbol (log2 of the tones)

◆ charRate()

float tinymodem::OliviaConfig::charRate ( ) const

inline

characters per second

◆ firstCarrier()

int tinymodem::OliviaConfig::firstCarrier ( ) const

inline

lowest tone as FFT bin (like fldigi)

◆ isMode()

bool tinymodem::OliviaConfig::isMode ( const char * mode )

inlinestatic

true if the mode is an Olivia or Contestia mode

◆ isValid()

bool tinymodem::OliviaConfig::isValid ( ) const

inline

Checks the configuration: returns false (and logs the reason) if invalid.

◆ parseMode()

bool tinymodem::OliviaConfig::parseMode	(	const char *	mode,
		int &	tones,
		int &	bandwidth,
		bool &	contestia )

inlinestaticprotected

◆ setMode()

bool tinymodem::OliviaConfig::setMode ( const char * mode )

inline

Selects e.g. "olivia-32-1000", "olivia-8-250" or "contestia-8-250": returns false if invalid. The other settings are kept.

◆ startsWith()

bool tinymodem::OliviaConfig::startsWith	(	const char *	str,
		const char *	prefix )

inlinestaticprotected

◆ symbolLen()

int tinymodem::OliviaConfig::symbolLen ( ) const

inline

FFT length (window of a symbol) in samples at 8000 Hz.

◆ symbolRate()

float tinymodem::OliviaConfig::symbolRate ( ) const

inline

symbols per second

◆ symbolSepar()

int tinymodem::OliviaConfig::symbolSepar ( ) const

inline

distance of two symbols in samples at 8000 Hz

◆ symbolsPerBlock()

int tinymodem::OliviaConfig::symbolsPerBlock ( ) const

inline

symbols per FEC block: 64 for Olivia, 32 for Contestia

◆ toneFreq()

float tinymodem::OliviaConfig::toneFreq ( int tone ) const

inline

frequency of a tone in Hz

Member Data Documentation

◆ bandwidth

int tinymodem::OliviaConfig::bandwidth = 1000

bandwidth in Hz: 125, 250, 500, 1000 or 2000

◆ BASE_RATE

float tinymodem::OliviaConfig::BASE_RATE = 8000.0f

staticconstexpr

internal sample rate which defines the signal

◆ center_freq

float tinymodem::OliviaConfig::center_freq = 1500.0f

center frequency in Hz

◆ channel

uint8_t tinymodem::OliviaConfig::channel = 0

receiver: input channel which is used for the decoding

◆ contestia

bool tinymodem::OliviaConfig::contestia = false

Contestia instead of Olivia.

◆ MAX_SYMBOL_LEN

int tinymodem::OliviaConfig::MAX_SYMBOL_LEN = 2048

staticconstexpr

largest supported FFT length

◆ rx_noise

float tinymodem::OliviaConfig::rx_noise = 0.0f

receiver: (testing only) amplitude of added uniform noise

◆ rx_one

bool tinymodem::OliviaConfig::rx_one = false

receiver: stop after the first transmission

◆ start_tones

bool tinymodem::OliviaConfig::start_tones = true

transmitter: send the start and stop tones (like fldigi)

◆ sync_integration

int tinymodem::OliviaConfig::sync_integration = 4

receiver: integration period of the synchronizer in FEC blocks

◆ sync_margin

int tinymodem::OliviaConfig::sync_margin = 8

receiver: search range for the frequency in tone spacings / 2 (fldigi: tune margin): limited to the available audio band

◆ sync_threshold

float tinymodem::OliviaConfig::sync_threshold = 3.0f

receiver: minimum signal to noise ratio of the synchronizer

◆ tones

int tinymodem::OliviaConfig::tones = 32

number of tones (power of 2: 2 - 256)

◆ volume

float tinymodem::OliviaConfig::volume = 1.0f

transmit amplitude (0.0 - 1.0)

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

src/modem/Olivia.h

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Static Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ OliviaConfig()

Member Function Documentation

◆ bitsPerCharacter()

◆ bitsPerSymbol()

◆ charRate()

◆ firstCarrier()

◆ isMode()

◆ isValid()

◆ parseMode()

◆ setMode()

◆ startsWith()

◆ symbolLen()

◆ symbolRate()

◆ symbolSepar()

◆ symbolsPerBlock()

◆ toneFreq()

Member Data Documentation

◆ bandwidth

◆ BASE_RATE

◆ center_freq

◆ channel

◆ contestia

◆ MAX_SYMBOL_LEN

◆ rx_noise

◆ rx_one

◆ start_tones

◆ sync_integration

◆ sync_margin

◆ sync_threshold

◆ tones

◆ volume