digital_cpmmod_bc Class Reference

Generic CPM modulator. More...

#include <digital_cpmmod_bc.h>

Inheritance diagram for digital_cpmmod_bc:

List of all members.

Public Member Functions
std::vector< float >	get_taps ()
	Return the phase response FIR taps.
Protected Member Functions
	digital_cpmmod_bc (gr_cpm::cpm_type type, float h, unsigned samples_per_sym, unsigned L, double beta)
Friends
DIGITAL_API digital_cpmmod_bc_sptr	digital_make_cpmmod_bc (int type, float h, unsigned samples_per_sym, unsigned L, double beta)

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Detailed Description

Generic CPM modulator.

Examples:

• Setting h = 0.5, L = 1, type = LREC yields MSK.
• Setting h = 0.5, type = GAUSSIAN and beta = 0.3 yields GMSK as used in GSM.

The input of this block are symbols from an M-ary alphabet +/-1, +/-3, ..., +/-(M-1). Usually, M = 2 and therefore, the valid inputs are +/-1. The modulator will silently accept any other inputs, though. The output is the phase-modulated signal.

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Constructor & Destructor Documentation

digital_cpmmod_bc::digital_cpmmod_bc	(	gr_cpm::cpm_type	type,
		float	h,
		unsigned	samples_per_sym,
		unsigned	L,
		double	beta
	)		[protected]

Build a generic CPM modulator block.

Parameters:

type	The modulation type. Can be one of LREC, LRC, LSRC, TFM or GAUSSIAN. See gr_cpm::phase_response() for a detailed description.
h	The modulation index. is the maximum phase change that can occur between two symbols, i.e., if you only send ones, the phase will increase by every samples_per_sym samples. Set this to 0.5 for Minimum Shift Keying variants.
samples_per_sym	Samples per symbol.
L	The length of the phase duration in symbols. For L=1, this yields full- response CPM symbols, for L > 1, partial-response.
beta	For LSRC, this is the rolloff factor. For Gaussian pulses, this is the 3 dB time-bandwidth product.

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Member Function Documentation

std::vector<float> digital_cpmmod_bc::get_taps

(

)

[inline]

Return the phase response FIR taps.

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Friends And Related Function Documentation

DIGITAL_API digital_cpmmod_bc_sptr digital_make_cpmmod_bc	(	int	type,
		float	h,
		unsigned	samples_per_sym,
		unsigned	L,
		double	beta
	)		[friend]

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

• digital_cpmmod_bc.h