Transpositional modulation systems and methods

• US 9,014,293 B2
• Filed: 03/15/2013
• Issued: 04/21/2015
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: TM IP Holdings LLC
• Original Assignee: TM IP Holdings LLC
• Inventors: Gerdes, Richard C.
• Primary Examiner(s): Ghulamali, Qutbuddin
• Application Number:
  US13/841,889
• Publication Number:
  US 20140269969A1
• Time in Patent Office: 767 Days
• Field of Search: 375/269, 375/273, 375/277, 375/276, 375/281, 375/286
• US Class Current: 375/269
• CPC Class Codes: H04L 2027/0051 Harmonic tracking
• CPC Class Codes: H04L 2027/0055 single phase
• CPC Class Codes: H04L 2027/0067 Phase error detectors
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence
• CPC Class Codes: H04L 27/10 Frequency-modulated carrier systems, i.e. using frequency-shift keying H04L27/32 takes precedence
• CPC Class Codes: H04L 27/122 using digital generation of carrier signals digital function generators G06F1/02, H04L17/10; generating pulses having stepped portions using digital techniques H03K4/026
• CPC Class Codes: H04L 27/14 Demodulator circuits; Receiver circuits
• CPC Class Codes: H04L 27/30 wherein each code element is represented by a combination of frequencies
• CPC Class Codes: H04L 27/32 Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
• CPC Class Codes: H04L 7/0331 with a digital phase-locked loop [PLL] processing binary samples, e.g. add/subtract logic for correction of receiver clock H04L7/0337 takes precedence

Abstract

Systems and methods for transpositional modulation and demodulation are provided. One such method for generating a signal includes the steps of providing a look-up table having a plurality of quarter-cycle waveforms, each of said quarter-cycle waveforms associated with a respective input level; receiving an input signal; and outputting quarter-cycle waveforms associated with levels of the received input signal. Systems for transpositional modulation are also provided. One such system for generating a signal includes a look-up table having a plurality of quarter-cycle waveforms. Each of the quarter-cycle waveforms are associated with a respective input level, and the look-up table is configured to receive an input signal, and output quarter-cycle waveforms associated with levels of the received input signal.

Claims

1. A method of generating a signal, comprising the steps of:

receiving a carrier signal;

receiving an input signal, wherein said input signal conveys a modulation level;

generating quarter-cycle waveforms based on the input signal; and

assembling the generated quarter-cycle waveforms into a continuous output signal, wherein the output signal includes a first inflection between adjacent quarter-cycles forming a segment of the output signal between a first negative peak and a positive peak, and wherein the output signal includes a second inflection between adjacent quarter-cycles forming a segment of the output signal between the positive peak and a second negative peak, wherein said first and second inflections represent said modulation level.

2. The method of claim 1, wherein said modulation levels of said adjacent quarter-cycles are different.

3. The method of claim 1, wherein the quarter-cycle waveforms are generated as cosine segments of 180°

length, at twice the carrier signal frequency, and wherein a first quarter-cycle waveform is generated at the equivalent carrier frequency quadrant of 0°

-90°

, a second quarter-cycle waveform is generated at the equivalent carrier frequency quadrant of 90°

-180°

, a third quarter-cycle waveform is generated at the equivalent carrier frequency quadrant of 180°

-270°

, and a fourth quarter-cycle waveform is generated at the equivalent carrier frequency quadrant of 270°

-360°

.

4. The method of claim 3, wherein the quarter-cycle waveforms are generated by a waveform generator or by software.

5. The method of claim 3, further comprising the step of:

frequency-shifting a third harmonic component of the output signal to the carrier signal frequency, and, wherein the third harmonic component preferably is frequency-shifted to the carrier signal frequency by generating a second harmonic and mixing the second and third harmonics.

6. A system for generating a signal, comprising:

a waveform generator configured to generate quarter-cycle waveforms based on a received carrier signal and a received input signal, wherein said input signal conveys a modulation level; and

an analog gate for assembling the generated quarter-cycle waveforms into a continuous output signal, wherein the output signal includes a first inflection between adjacent quarter-cycles forming a segment of the output signal between a first negative peak and a positive peak, and wherein the output signal includes a second inflection between adjacent quarter-cycles forming a segment of the output signal between the positive peak and a second negative peak, wherein said first and second inflections represent said modulation level.

7. The system of claim 6, wherein said modulation levels of said adjacent quarter cycles are different.

8. The system of claim 6, wherein the quarter-cycle waveforms are generated as cosine segments of 180°

length, at twice the carrier signal frequency, and wherein a first quarter-cycle waveform is generated at the equivalent carrier frequency quadrant of 0°

-90°

, a second quarter-cycle waveform is generated at the equivalent carrier frequency quadrant of 90°

480°

, a third quarter-cycle waveform is generated at the equivalent carrier frequency quadrant of 180°

-270°

, and a fourth quarter-cycle waveform is generated at the equivalent carrier frequency quadrant of 270°

-360°

.

9. The system of claim 6, further comprising:

(a) a frequency-shifter for frequency-shifting a third harmonic component of the output signal to the carrier signal frequency, and/or

(b) a phase-locked loop for generating a second harmonic component; and

a mixer, wherein the third harmonic component is frequency-shifted to the carrier signal frequency by mixing the second and third harmonics.