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 communicating signals using a multi-dimensional symbol constellation. In one example, a process for modulating a carrier signal includes the actions of mapping data to symbols of a multi-dimensional symbol constellation that includes at least three dimensions, each dimension of the constellation represented by a respective modulation signal. The dimensions of the constellation include first and second dimensions each of which are represented by respective in-phase modulation values and quadrature phase modulation values of a quadrature amplitude modulation (QAM) signal, and a third dimension represented by a transpositional modulation (TM) signal. The method further includes modulating a carrier signal with the TM signal and the QAM 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 communicating signals using a multi-dimensional symbol constellation. In one example, a process for modulating a carrier signal includes the actions of mapping data to symbols of a multi-dimensional symbol constellation that includes at least three dimensions, each dimension of the constellation represented by a respective modulation signal. The dimensions of the constellation include first and second dimensions each of which are represented by respective in-phase modulation values and quadrature phase modulation values of a quadrature amplitude modulation (QAM) signal, and a third dimension represented by a transpositional modulation (TM) signal. The method further includes modulating a carrier signal with the TM signal and the QAM signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for communicating signals using a multi-dimensional symbol constellation. In one example, a process for modulating a carrier signal includes the actions of mapping data to symbols of a multi-dimensional symbol constellation that includes at least three dimensions, each dimension of the constellation represented by a respective modulation signal. The dimensions of the constellation include first and second dimensions each of which are represented by respective in-phase modulation values and quadrature phase modulation values of a quadrature amplitude modulation (QAM) signal, and a third dimension represented by a transpositional modulation (TM) signal. The method further includes modulating a carrier signal with the TM signal and the QAM signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for detecting electronic counter measure (ECM) signals and embedding covert messages in radar or sonar signals. In one aspect, a method for detecting ECM signals includes receiving a radar return signal from an object. The method includes determining whether radar return signal includes a TM signal, and identifying the radar return signal as a skin return signal or an electronic counter measure signal based on whether the radar return signal includes the TM 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 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 communicating signals using a multi-dimensional symbol constellation. In one example, a process for modulating a carrier signal includes the actions of mapping data to symbols of a multi-dimensional symbol constellation that includes at least three dimensions, each dimension of the constellation represented by a respective modulation signal. The dimensions of the constellation include first and second dimensions each of which are represented by respective in-phase modulation values and quadrature phase modulation values of a quadrature amplitude modulation (QAM) signal, and a third dimension represented by a transpositional modulation (TM) signal. The method further includes modulating a carrier signal with the TM signal and the QAM 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 communicating signals using a multi-dimensional symbol constellation. In one example, a process for modulating a carrier signal includes the actions of mapping data to symbols of a multi-dimensional symbol constellation that includes at least three dimensions, each dimension of the constellation represented by a respective modulation signal. The dimensions of the constellation include first and second dimensions each of which are represented by respective in-phase modulation values and quadrature phase modulation values of a quadrature amplitude modulation (QAM) signal, and a third dimension represented by a transpositional modulation (TM) signal. The method further includes modulating a carrier signal with the TM signal and the QAM 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: 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: Systems, methods and devices for transmitting and receiving and demodulating transpositional modulated signals, for increasing information bandwidth of defined communication channels, and for time-delay shifting an input signal in accordance to an input control signal are provided. One such method of increasing the information bandwidth of a defined communication channel includes receiving a first modulated signal having a first carrier signal frequency; receiving a second modulated signal having a second carrier signal frequency, the second modulated signal being modulated with information independent of information modulating the first carrier signal, the second carrier signal frequency being harmonically or sub-harmonically related to the first carrier signal frequency; and combining the first and second signals.

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 communicating signals using a multi-dimensional symbol constellation. In one example, a process for modulating a carrier signal includes the actions of mapping data to symbols of a multi-dimensional symbol constellation that includes at least three dimensions, each dimension of the constellation represented by a respective modulation signal. The dimensions of the constellation include first and second dimensions each of which are represented by respective in-phase modulation values and quadrature phase modulation values of a quadrature amplitude modulation (QAM) signal, and a third dimension represented by a transpositional modulation (TM) signal. The method further includes modulating a carrier signal with the TM signal and the QAM 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.