gr::digital Namespace Reference

Classes
class	additive_scrambler_bb
	Scramble an input stream using an LFSR. More...
class	binary_slicer_fb
	Slice float binary symbol producing 1 bit output. More...
class	burst_shaper
	Burst shaper block for applying burst padding and ramping. More...
class	chunks_to_symbols
	Map a stream of unpacked symbol indexes to stream of float or complex constellation points in D dimensions (D = 1 by default) More...
class	clock_recovery_mm_cc
	Mueller and Müller (M&M) based clock recovery block with complex input, complex output. More...
class	clock_recovery_mm_ff
	Mueller and Müller (M&M) based clock recovery block with float input, float output. More...
class	cma_equalizer_cc
	Implements constant modulus adaptive filter on complex stream. More...
class	constellation
	An abstracted constellation object. More...
class	constellation_16qam
	Digital constellation for 16qam. More...
class	constellation_8psk
	Digital constellation for 8PSK. More...
class	constellation_8psk_natural
	Digital constellation for natually mapped 8PSK. More...
class	constellation_bpsk
	Digital constellation for BPSK . More...
class	constellation_calcdist
	Calculate Euclidian distance for any constellation. More...
class	constellation_decoder_cb
	Constellation Decoder. More...
class	constellation_dqpsk
	Digital constellation for DQPSK. More...
class	constellation_expl_rect
	Rectangular digital constellation. More...
class	constellation_psk
	constellation_pskConstellation space is divided into pie slices sectors. More...
class	constellation_qpsk
	Digital constellation for QPSK. More...
class	constellation_receiver_cb
	This block makes hard decisions about the received symbols (using a constellation object) and also fine tunes phase synchronization. More...
class	constellation_rect
	Rectangular digital constellationOnly implemented for 1-(complex)dimensional constellation. More...
class	constellation_sector
	Sectorized digital constellation. More...
class	constellation_soft_decoder_cf
	Constellation Decoder. More...
class	corr_est_cc
class	correlate_access_code_bb
	Examine input for specified access code, one bit at a time. More...
class	correlate_access_code_bb_ts
	Examine input for specified access code, one bit at a time. More...
class	correlate_access_code_ff_ts
	Examine input for specified access code, one bit at a time. More...
class	correlate_access_code_tag_bb
	Examine input for specified access code, one bit at a time. More...
class	correlate_access_code_tag_ff
	Examine input for specified access code, one bit at a time. More...
class	costas_loop_cc
	A Costas loop carrier recovery module. More...
class	cpmmod_bc
	Generic CPM modulator. More...
class	crc32_async_bb
	Byte-stream CRC block for async messages. More...
class	crc32_bb
	Byte-stream CRC block. More...
class	descrambler_bb
	Descramber an input stream using an LFSR. More...
class	diff_decoder_bb
	Differential encoder: y[0] = (x[0] - x[-1]) % M. More...
class	diff_encoder_bb
	Differential decoder: y[0] = (x[0] + y[-1]) % M. More...
class	diff_phasor_cc
	Differential decoding based on phase change. More...
class	fll_band_edge_cc
	Frequency Lock Loop using band-edge filters. More...
class	framer_sink_1
	Given a stream of bits and access_code flags, assemble packets. More...
class	glfsr
	Galois Linear Feedback Shift Register using specified polynomial mask. More...
class	glfsr_source_b
	Galois LFSR pseudo-random source. More...
class	glfsr_source_f
	Galois LFSR pseudo-random source generating float outputs -1.0 - 1.0. More...
class	hdlc_deframer_bp
	HDLC deframer which takes in unpacked bits, and outputs PDU binary blobs. Frames which do not pass CRC are rejected. More...
class	hdlc_framer_pb
	HDLC framer which takes in PMT binary blobs and outputs HDLC frames as unpacked bits, with CRC and bit stuffing added. The first sample of the frame is tagged with the tag frame_tag_name and includes a length field for tagged_stream use. More...
class	header_buffer
	Helper class for handling payload headers. More...
class	header_format_base
	Base header formatter class. More...
class	header_format_counter
	Header formatter that adds the payload bits/symbol format and a packet number counter. More...
class	header_format_crc
	Header formatter that includes the payload length, packet number, and a CRC check on the header. More...
class	header_format_default
	Default header formatter for PDU formatting. More...
class	header_format_ofdm
	Header formatter that includes the payload length, packet number, and a CRC check on the header. More...
class	header_payload_demux
	Header/Payload demuxer (HPD). More...
class	kurtotic_equalizer_cc
	Implements a kurtosis-based adaptive equalizer on complex stream. More...
class	lfsr
	Fibonacci Linear Feedback Shift Register using specified polynomial mask. More...
class	lms_dd_equalizer_cc
	Least-Mean-Square Decision Directed Equalizer (complex in/out) More...
class	map_bb
	output[i] = map[input[i]] More...
class	mpsk_snr_est
	A parent class for SNR estimators, specifically for M-PSK signals in AWGN channels. More...
class	mpsk_snr_est_cc
	A block for computing SNR of a signal. More...
class	mpsk_snr_est_m2m4
	SNR Estimator using 2nd and 4th-order moments. More...
class	mpsk_snr_est_simple
	SNR Estimator using simple mean/variance estimates. More...
class	mpsk_snr_est_skew
	SNR Estimator using skewness correction. More...
class	mpsk_snr_est_svr
	Signal-to-Variation Ratio SNR Estimator. More...
class	msk_timing_recovery_cc
	MSK/GMSK timing recoveryThis block performs timing synchronization on CPM modulations using a fourth-order nonlinearity feedback method which is non-data-aided. The block does not require prior phase synchronization but is relatively sensitive to frequency offset (keep offset to 0.1x symbol rate). More...
class	ofdm_carrier_allocator_cvc
	Create frequency domain OFDM symbols from complex values, add pilots. More...
class	ofdm_chanest_vcvc
	Estimate channel and coarse frequency offset for OFDM from preamblesInput: OFDM symbols (in frequency domain). The first one (or two) symbols are expected to be synchronisation symbols, which are used to estimate the coarse freq offset and the initial equalizer taps (these symbols are removed from the stream). The following n_data_symbols are passed through unmodified (the actual equalisation must be done elsewhere). Output: The data symbols, without the synchronisation symbols. The first data symbol passed through has two tags: 'ofdm_sync_carr_offset' (integer), the coarse frequency offset as number of carriers, and 'ofdm_sync_eq_taps' (complex vector). Any tags attached to the synchronisation symbols are attached to the first data symbol. All other tags are propagated as expected. More...
class	ofdm_cyclic_prefixer
	Adds a cyclic prefix and performs pulse shaping on OFDM symbols. More...
class	ofdm_equalizer_1d_pilots
class	ofdm_equalizer_base
	Base class for implementation details of frequency-domain OFDM equalizers. More...
class	ofdm_equalizer_simpledfe
	Simple decision feedback equalizer for OFDM. More...
class	ofdm_equalizer_static
	Very simple static equalizer for OFDM. More...
class	ofdm_frame_equalizer_vcvc
	OFDM frame equalizer. More...
class	ofdm_serializer_vcc
	Serializes complex modulations symbols from OFDM sub-carriers. More...
class	ofdm_sync_sc_cfb
	Schmidl & Cox synchronisation for OFDM. More...
class	packet_header_default
	Default header formatter for digital packet transmission. More...
class	packet_header_ofdm
	Header utility for OFDM signals. More...
class	packet_headergenerator_bb
	Generates a header for a tagged, streamed packet. More...
class	packet_headerparser_b
	Post header metadata as a PMT. More...
class	packet_sink
	process received bits looking for packet sync, header, and process bits into packet More...
class	pfb_clock_sync_ccf
	Timing synchronizer using polyphase filterbanks. More...
class	pfb_clock_sync_fff
	Timing synchronizer using polyphase filterbanks. More...
class	pn_correlator_cc
	PN code sequential search correlator. More...
class	probe_density_b
class	probe_mpsk_snr_est_c
	A probe for computing SNR of a PSK signal. More...
class	protocol_formatter_async
	Uses a header format object to append a header onto a PDU. More...
class	protocol_formatter_bb
	Uses a header format object to create a header from a tagged stream packet. More...
class	protocol_parser_b
	Block that synchronizes to a header based on a header format object class. Designed to accept hard bits and produce PDUs with packed bytes (pmt::u8vector). More...
class	scrambler_bb
	Scramble an input stream using an LFSR. More...
class	simple_correlator
	inverse of simple_framer (more or less) More...
class	simple_framer
	add sync field, seq number and command field to payload More...
class	snr_est_m2m4
	SNR Estimator using 2nd and 4th-order moments. More...
class	symbol_sync_cc
	Symbol Synchronizer block with complex input, complex output. More...
class	symbol_sync_ff
	Symbol Synchronizer block with float input, float output. More...

Typedefs
typedef burst_shaper< float >	burst_shaper_ff
typedef burst_shaper< gr_complex >	burst_shaper_cc
typedef chunks_to_symbols< std::uint8_t, float >	chunks_to_symbols_bf
typedef chunks_to_symbols< std::uint8_t, gr_complex >	chunks_to_symbols_bc
typedef chunks_to_symbols< std::int16_t, float >	chunks_to_symbols_sf
typedef chunks_to_symbols< std::int16_t, gr_complex >	chunks_to_symbols_sc
typedef chunks_to_symbols< std::int32_t, float >	chunks_to_symbols_if
typedef chunks_to_symbols< std::int32_t, gr_complex >	chunks_to_symbols_ic

Enumerations
enum	tm_type { THRESHOLD_DYNAMIC, THRESHOLD_ABSOLUTE }
	Correlate stream with a pre-defined sequence and estimate peak. More...
enum	ir_type { IR_NONE = -1, IR_MMSE_8TAP = 0, IR_PFB_NO_MF = 1, IR_PFB_MF = 2 }
enum	trellis_metric_type_t { TRELLIS_EUCLIDEAN = 200, TRELLIS_HARD_SYMBOL, TRELLIS_HARD_BIT }
enum	snr_est_type_t { SNR_EST_SIMPLE = 0, SNR_EST_SKEW, SNR_EST_M2M4, SNR_EST_SVR }
	A block for computing SNR of a signal. More...
enum	ted_type {   TED_NONE = -1, TED_MUELLER_AND_MULLER = 0, TED_MOD_MUELLER_AND_MULLER = 1, TED_ZERO_CROSSING = 2,   TED_GARDNER = 4, TED_EARLY_LATE = 5, TED_DANDREA_AND_MENGALI_GEN_MSK = 6, TED_SIGNAL_TIMES_SLOPE_ML = 7,   TED_SIGNUM_TIMES_SLOPE_ML = 8, TED_MENGALI_AND_DANDREA_GMSK = 9 }

Functions
DIGITAL_API unsigned int	update_crc32 (unsigned int crc, const unsigned char *buf, size_t len)
	update running CRC-32 More...
DIGITAL_API unsigned int	update_crc32 (unsigned int crc, const std::string buf)
DIGITAL_API unsigned int	crc32 (const unsigned char *buf, size_t len)
DIGITAL_API unsigned int	crc32 (const std::string buf)
DIGITAL_API std::vector< gr_complex >	modulate_vector_bc (basic_block_sptr modulator, std::vector< uint8_t > data, std::vector< float > taps)
	Modulate a vector of data and apply a shaping filter. More...

Variables
static const unsigned long long	GRSF_SYNC = 0xacdda4e2f28c20fcULL
static const int	GRSF_BITS_PER_BYTE = 8
static const int	GRSF_SYNC_OVERHEAD = sizeof(GRSF_SYNC)
static const int	GRSF_PAYLOAD_OVERHEAD = 1
static const int	GRSF_TAIL_PAD = 1
static const int	GRSF_OVERHEAD

Typedef Documentation

burst_shaper_cc

typedef burst_shaper<gr_complex> gr::digital::burst_shaper_cc

burst_shaper_ff

typedef burst_shaper<float> gr::digital::burst_shaper_ff

chunks_to_symbols_bc

typedef chunks_to_symbols<std::uint8_t, gr_complex> gr::digital::chunks_to_symbols_bc

chunks_to_symbols_bf

typedef chunks_to_symbols<std::uint8_t, float> gr::digital::chunks_to_symbols_bf

chunks_to_symbols_ic

typedef chunks_to_symbols<std::int32_t, gr_complex> gr::digital::chunks_to_symbols_ic

chunks_to_symbols_if

typedef chunks_to_symbols<std::int32_t, float> gr::digital::chunks_to_symbols_if

chunks_to_symbols_sc

typedef chunks_to_symbols<std::int16_t, gr_complex> gr::digital::chunks_to_symbols_sc

chunks_to_symbols_sf

typedef chunks_to_symbols<std::int16_t, float> gr::digital::chunks_to_symbols_sf

Enumeration Type Documentation

ir_type

enum gr::digital::ir_type

Enumerator
IR_NONE
IR_MMSE_8TAP
IR_PFB_NO_MF
IR_PFB_MF

ted_type

enum gr::digital::ted_type

Enumerator
TED_NONE
TED_MUELLER_AND_MULLER
TED_MOD_MUELLER_AND_MULLER
TED_ZERO_CROSSING
TED_GARDNER
TED_EARLY_LATE
TED_DANDREA_AND_MENGALI_GEN_MSK
TED_SIGNAL_TIMES_SLOPE_ML
TED_SIGNUM_TIMES_SLOPE_ML
TED_MENGALI_AND_DANDREA_GMSK

trellis_metric_type_t

enum gr::digital::trellis_metric_type_t

Enumerator
TRELLIS_EUCLIDEAN
TRELLIS_HARD_SYMBOL
TRELLIS_HARD_BIT

Function Documentation

crc32() [1/2]

DIGITAL_API unsigned int gr::digital::crc32	(	const unsigned char *	buf,
		size_t	len
	)

crc32() [2/2]

DIGITAL_API unsigned int gr::digital::crc32

(

const std::string

buf

)

modulate_vector_bc()

DIGITAL_API std::vector<gr_complex> gr::digital::modulate_vector_bc	(	basic_block_sptr	modulator,
		std::vector< uint8_t >	data,
		std::vector< float >	taps
	)

Modulate a vector of data and apply a shaping filter.

modulator: Pointer to a byte-to-complex modulator block. data: Vector of bytes to modulate into symbols. taps: Post-modulation symbol shaping filter taps.

This function modulates the input vector and applies a symbol shaping filter. It is intended for use with the corr_est_cc block as the symbol stream to correlate against.

Any differential encoding or other data coding must be performed on the input vector before this modulation operation.

Be aware that the format of the incoming data must match the format the modulator block is expecting. GNURadio modulator blocks are inconsistent in their data type expectations. For instance, cpmmod_bc expects unpacked, signed bytes in (-1, 1), while gmsk_mod expects packed, unsigned bytes in (0, 1). In other words, the output of gmsk_mod given the input vector [0xaa, 0x00] is equivalent to the output of cpmmod_bc given the input vector [1,255,1,255,1,255,1,255,255,255,255,255,255,255,255,255]

Please check the documentation or source of the modulator before using this function.

update_crc32()

DIGITAL_API unsigned int gr::digital::update_crc32	(	unsigned int	crc,
		const std::string	buf
	)

Variable Documentation

GRSF_BITS_PER_BYTE

const int gr::digital::GRSF_BITS_PER_BYTE = 8

static

GRSF_OVERHEAD

const int gr::digital::GRSF_OVERHEAD

static

Initial value:

=
    GRSF_SYNC_OVERHEAD + GRSF_PAYLOAD_OVERHEAD + GRSF_TAIL_PAD

GRSF_PAYLOAD_OVERHEAD

const int gr::digital::GRSF_PAYLOAD_OVERHEAD = 1

static

GRSF_SYNC

const unsigned long long gr::digital::GRSF_SYNC = 0xacdda4e2f28c20fcULL

static

Here are a couple of maximum length sequences (m-sequences) that were generated by the the "mseq" matlab/octave code downloaded from: http://www.mathworks.com/matlabcentral/fileexchange/990

31-bit m-sequence:
     0110100100001010111011000111110
     0x690AEC76 (padded on right with a zero)

63-bit m-sequence:
     101011001101110110100100111000101111001010001100001000001111110
     0xACDDA4E2F28C20FC (padded on right with a zero)

GRSF_SYNC_OVERHEAD

const int gr::digital::GRSF_SYNC_OVERHEAD = sizeof(GRSF_SYNC)

static

GRSF_TAIL_PAD

const int gr::digital::GRSF_TAIL_PAD = 1

static