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US 9,853,849 B1Granted
Systems and methods to produce a cyclically generated, continuous phase, frequency shift keying waveform
AssigneeFrontier Analytics, LLC
InventorsMichael Joseph Geile, David Maldonado Febus
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Abstract
Systems and methods are disclosed for producing a cyclically generated, continuous-phase, frequency-shift keying (CG-CPFSK) waveform which may be used for wired and/or wireless communication systems. Such waveforms may have a substantially constant modulus and have an underlying cyclic phase structure. Systems and methods are also disclosed for generating a waveform based on a cyclically continuous signal which may be subsequently translated into a radio frequency for transmission.
Claims18
A system for converting a symbol frame to a normalized cyclic frame, the system comprising a waveform generator having one or more processing elements arranged to:
- convert the symbol frame having K samples into a frequency-domain vector by performing a discrete Fourier transform (DFT) on the symbol frame, wherein the frequency-domain vector comprises K members, and K is a non-zero positive integer;
- create an extended frequency-domain vector having L members by adding one or more predetermined frequency-domain members to the frequency-domain vector, wherein L is greater than K, and L is a positive integer;
- weight each of the L members of the extended frequency-domain vector to produce a weighted extended frequency-domain vector such that the weighted extended frequency-domain vector is both bandwidth limited in the frequency domain and the corresponding time-domain representation of the weighted extended frequency-domain vector is cyclically continuous in the time domain;
- convert the weighted extended frequency-domain vector into a complex-valued cyclic frame by performing an inverse discrete Fourier transform (IDFT) on the weighted extended frequency-domain vector, wherein the complex-value cyclic frame comprises L samples having a complex value;
- create a real-valued cyclic frame by taking the real part of the complex-valued cyclic frame;
- and
- multiply each of the L samples of the real-valued cyclic frame by a scale factor, G, to produce a normalized cyclic frame comprising L samples, and the scale factor, G, is based on a predetermined phase rotation value ascribed to a modulated pulse in the real-valued cyclic frame.
4 more elements
A system for modulating a carrier waveform with a cyclic waveform corresponding to K symbols from a sequence of symbols, the system comprising a waveform generator having one or more processing elements arranged to:
- create a symbol frame comprising K symbols from the sequence of symbols, wherein K is a non-zero positive integer;
- convert the symbol frame into a frequency-domain vector by performing a discrete Fourier transform (DFT) on the symbol frame, wherein the frequency-domain vector comprises K members;
- create an extended frequency-domain vector having L members by adding one or more predetermined frequency-domain members to the frequency-domain vector, wherein L is greater than K, and L is a positive integer;
- weight each of the L members of the extended frequency-domain vector to produce a weighted extended frequency-domain vector such that the weighted extended frequency-domain vector is both bandwidth limited in the frequency domain and the corresponding time-domain representation of the weighted extended frequency-domain vector is cyclically continuous in the time domain;
- convert the weighted extended frequency-domain vector into a complex-valued cyclic frame by performing an inverse discrete Fourier transform (IDFT) on the weighted extended frequency-domain vector, wherein the complex-valued cyclic frame comprises L samples;
- create a real-valued cyclic frame by taking the real part of the complex-valued cyclic frame;
- multiply each of the L samples of the real-valued cyclic frame by a scale factor, G, to produce a normalized cyclic frame comprising L samples, and the scale factor, G, is based on one or more predetermined phase rotation values and the sum of the L samples of the real-valued cyclic frame containing a single reference pulse;
- and
- modulate the carrier waveform with the L samples of the normalized cyclic frame by adjusting the frequency of the carrier waveform based on the amplitude of the L samples of the normalized cyclic frame.
6 more elements
A method for converting a symbol frame to a normalized cyclic frame, the method comprising:
- converting the symbol frame having K samples into a frequency-domain vector by performing a discrete Fourier transform (DFT) on the symbol frame, wherein the frequency-domain vector comprises K members, and K is a non-zero positive integer;
- creating an extended frequency-domain vector having L members by adding one or more predetermined frequency-domain members to the frequency-domain vector, wherein L is greater than K, and L is a positive integer;
- weighting each of the L members of the extended frequency-domain vector to produce a weighted extended frequency-domain vector such that the weighted extended frequency-domain vector is both bandwidth limited in the frequency domain and the corresponding time-domain representation of the weighted extended frequency-domain vector is cyclically continuous in the time domain;
- converting the weighted extended frequency-domain vector into a complex-valued cyclic frame by performing an inverse discrete Fourier transform (IDFT) on the weighted extended frequency-domain vector, wherein the complex-valued cyclic frame comprises L samples;
- create a real-valued cyclic frame by taking the real part of the complex-valued cyclic frame;
- and
- multiplying each of the L samples of the real-valued cyclic frame by a scale factor, G, to produce a normalized cyclic frame comprising L samples, and the scale factor, G, is based on a predetermined phase rotation value and the sum of the real portion of the L samples of the real-valued cyclic frame containing a single reference pulse.
4 more elements
Dependencies are inferred from the claim text.