Abstract: Methods, systems, and apparatus for detecting a center frequency of an input signal, the input signal including a carrier signal modulated with a modulation signal. Detecting a frequency of a second signal. Determining a difference signal between the center frequency of the input signal and the frequency of the second signal. Modifying the frequency of the second signal based on the difference signal to provide the carrier signal. And, outputting the carrier signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium for receiving, by a first device, a first signal from a second device, the first signal including a carrier signal modulated with a first modulation signal. Detecting a frequency of the carrier signal by performing a carrier extraction (CAREX) process on the first signal. Adding a second modulation signal to the carrier signal of the first signal to produce a combined signal, wherein the second modulation signal is a transpositional modulation (TM) signal and the first modulation signal is a non-TM signal. Transmitting the combined signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining, by a first device, that a second device is within range for direct communications and that the second device is capable of performing transpositional modulation (TM) communications. Determining to use transpositional modulation to send data to the second device. Sending the data to the second device using a TM signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transmitting, by a first device, a transmission signal that includes a carrier signal modulated with a TM signal. Receiving a response signal from a second device in response to the transmission signal. Determining, whether the response signal includes the TM signal.

Abstract: Methods, systems, and apparatus for receiving an input signal, where the input signal includes a carrier signal modulated with a first modulation signal and a second modulation signal, and where the second modulation signal is a TM signal. Demodulating the first modulation signal from the input signal. Modulating an un-modulated carrier signal with the first modulation signal to generate a third signal, where the third signal includes the carrier signal modulated by the first modulation signal. And, removing the first modulation signal from the input signal by subtracting the third signal from the input signal to extract the TM signal from the input signal.

Abstract: Methods, systems, and apparatus for detecting a center frequency of an input signal, the input signal including a carrier signal modulated with a modulation signal. Detecting a frequency of a second signal. Determining a difference signal between the center frequency of the input signal and the frequency of the second signal. Modifying the frequency of the second signal based on the difference signal to provide the carrier signal. And, outputting the carrier signal.

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.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transmitting, by a first device, a transmission signal that includes a carrier signal modulated with a TM signal. Receiving a response signal from a second device in response to the transmission signal. Determining, whether the response signal includes the TM signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium for receiving, by a first device, a first signal from a second device, the first signal including a carrier signal modulated with a first modulation signal. Detecting a frequency of the carrier signal by performing a carrier extraction (CAREX) process on the first signal. Adding a second modulation signal to the carrier signal of the first signal to produce a combined signal, wherein the second modulation signal is a transpositional modulation (TM) signal and the first modulation signal is a non-TM signal. Transmitting the combined signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for modulating and demodulating transpositional modulated (TM) signals. One aspect features a method of modulating a carrier signal that include the actions of generating a TM signal by generating a sinusoidal signal, and modulating the sinusoidal signal based on a data signal to provide the TM signal. Inserting the TM signal into a carrier signal to provide a TM modulated carrier signal. Modulating the TM modulated carrier signal with a non-TM signal to provide a combined signal. Transmitting the combined signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining, by a first device, that a second device is within range for direct communications and that the second device is capable of performing transpositional modulation (TM) communications. Determining to use transpositional modulation to send data to the second device. Sending the data to the second device using a TM signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transmitting, by a first device, a transmission signal that includes a carrier signal modulated with a TM signal. Receiving a response signal from a second device in response to the transmission signal. Determining, whether the response signal includes the TM signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining, by a first device, that a second device is within range for direct communications and that the second device is capable of performing transpositional modulation (TM) communications. Determining to use transpositional modulation to send data to the second device. Sending the data to the second device using a TM signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium for receiving, by a first device, a first signal from a second device, the first signal including a carrier signal modulated with a first modulation signal. Detecting a frequency of the carrier signal by performing a carrier extraction (CAREX) process on the first signal. Adding a second modulation signal to the carrier signal of the first signal to produce a combined signal, wherein the second modulation signal is a transpositional modulation (TM) signal and the first modulation signal is a non-TM signal. Transmitting the combined signal.

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.

Abstract: Methods, systems, and apparatus for receiving an input signal, where the input signal includes a carrier signal modulated with a first modulation signal and a second modulation signal, and where the second modulation signal is a TM signal. Demodulating the first modulation signal from the input signal. Modulating an un-modulated carrier signal with the first modulation signal to generate a third signal, where the third signal includes the carrier signal modulated by the first modulation signal. And, removing the first modulation signal from the input signal by subtracting the third signal from the input signal to extract the TM signal from the input signal.

Abstract: Methods, systems, and apparatus for detecting a center frequency of an input signal, the input signal including a carrier signal modulated with a modulation signal. Detecting a frequency of a second signal. Determining a difference signal between the center frequency of the input signal and the frequency of the second signal. Modifying the frequency of the second signal based on the difference signal to provide the carrier signal. And, outputting the carrier signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transmitting, by a first device, a transmission signal that includes a carrier signal modulated with a TM signal. Receiving a response signal from a second device in response to the transmission signal. Determining, whether the response signal includes the TM signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium for receiving, by a first device, a first signal from a second device, the first signal including a carrier signal modulated with a first modulation signal. Detecting a frequency of the carrier signal by performing a carrier extraction (CAREX) process on the first signal. Adding a second modulation signal to the carrier signal of the first signal to produce a combined signal, wherein the second modulation signal is a transpositional modulation (TM) signal and the first modulation signal is a non-TM signal. Transmitting the combined signal.

Abstract: Methods, systems, and apparatus for detecting a center frequency of an input signal, the input signal including a carrier signal modulated with a modulation signal. Detecting a frequency of a second signal. Determining a difference signal between the center frequency of the input signal and the frequency of the second signal. Modifying the frequency of the second signal based on the difference signal to provide the carrier signal. And, outputting the carrier signal.