Abstract: Disclosed are techniques for wireless communication. In an aspect, a wireless communications device transmits a first set of symbols of a plurality of symbols of a data stream using a first set of constellation points of a pi/N-based modulation scheme, and transmits a second set of symbols of the plurality of symbols using a second set of constellation points of the pi/N-based modulation scheme, wherein each of the first set of constellation points and the second set of constellation points consists of M constellation points, wherein the second set of constellation points is rotated from the first set of constellation points by pi/N, wherein symbols of the first set of symbols alternate with symbols of the second set of symbols, and wherein M is greater than 8.

Abstract: Methods, systems, and devices for an apparatus that performs near field communications are described. A near ultra low energy field (NULEF) system may be used in systems that come in close contact with the human body. NULEF-E may experience limited performance due to external electric fields generated by a human body. NULEF-E may also be used across other bodies having electrically conductive or semi-conductive surfaces. The interference of the external electric fields may be mitigated by increasing the electrical length between a transducer and an electrode of the system. In particular, a wire electrically connecting a transceiver and a electrode may have a wire length that is also an electrical length between the transceiver and the electrode, the wire being configured such that a physical distance between the electrode and the transceiver is less than the wire length while maintaining the electrical length.

Abstract: Methods, systems, and devices for an apparatus that performs near field communications are described. A near ultra low energy field (NULEF) system may be used in systems that come in close contact with the human body. NULEF-E may experience limited performance due to external electric fields generated by a human body. NULEF-E may also be used across other bodies having electrically conductive or semi-conductive surfaces. The interference of the external electric fields may be mitigated by increasing the electrical length between a transducer and an electrode of the system. In particular, a wire electrically connecting a transceiver and a electrode may have a wire length that is also an electrical length between the transceiver and the electrode, the wire being configured such that a physical distance between the electrode and the transceiver is less than the wire length while maintaining the electrical length.

Abstract: Techniques to enable near field communication using electric field (E-field) are proposed. When the wavelength of a signal is long relative to the human body, the human body can behave as a conductive hollow cylinder. By capacitively coupling the human body with a transmitter and/or a receiver, the human body itself can be used as a communication medium.

Abstract: Use of a Near Ultra-low Energy Field (NULEF) communications as a non-radiating means of gaining entry to a car when the car owner is near the car or touching the car body avoids the use of problematic radio signals that may be intercepted by thieves. In addition, a NULEF communications system may be used as a high bandwidth in-car communication system using either NULEF-E or NULEF-H.

Abstract: Use of a Near Ultra-low Energy Field (NULEF) communications as a non-radiating means of gaining entry to a car when the car owner is near the car or touching the car body avoids the use of problematic radio signals that may be intercepted by thieves. In addition, a NULEF communications system may be used as a high bandwidth in-car communication system using either NULEF-E or NULEF-H.

Abstract: According to various aspects and technical advantages, an apparatus for electronic shelf labels includes a controller circuit for communicating with communication devices using a contactless communication protocol, a set of two or more antenna coils, each antenna coil located at a known position relative to the controller circuit, and a switch for selectively coupling the controller circuit to one or more of the set of antenna coils.

Abstract: According to various aspects and technical advantages, an apparatus for electronic shelf labels includes a controller circuit for communicating with communication devices using a contactless communication protocol, a set of two or more antenna coils, each antenna coil located at a known position relative to the controller circuit, and a switch for selectively coupling the controller circuit to one or more of the set of antenna coils.

Abstract: This disclosure provides systems, methods and apparatuses, including computer programs encoded on computer-readable media, for near ultra-low energy field (NULEF) headset communications. In some aspects, a source device, located in a seat headrest, can generate a modulated magnetic field capable of transferring data via a magnetic communication link, such as a NULEF communication link. The source device can establish a wireless data transfer session with one or more sink devices, and at least one of the sink devices can be implemented to receive data via the NULEF communication link.

Abstract: Techniques to enable near field communication using electric field (E-field) are proposed. When the wavelength of a signal is long relative to the human body, the human body can behave as a conductive hollow cylinder. By capacitively coupling the human body with a transmitter and/or a receiver, the human body itself can be used as a communication medium.

Abstract: This disclosure provides systems, methods and apparatuses, including computer programs encoded on computer-readable media, for near ultra-low energy field (NULEF) headset communications. In some aspects, a source device, located in a seat headrest, can generate a modulated magnetic field capable of transferring data via a magnetic communication link, such as a NULEF communication link. The source device can establish a wireless data transfer session with one or more sink devices, and at least one of the sink devices can be implemented to receive data via the NULEF communication link.

Abstract: The disclosure relates to techniques to increase the range over which magnetic field induction can be used to communicate data between a transmitting antenna and a receiving antenna. In particular, a transceiver may comprise an antenna configured to transmit a signal via magnetic field induction, a transmit section having an amplifier, a capacitance, and a resistance arranged to form a parallel resonant circuit, and a processing unit configured to generate the signal transmitted via the antenna and to use a spreading code to modulate the signal to be transmitted via the antenna.

Abstract: Various aspects described herein relate to techniques and modulation schemes used in near-field communications systems. A method for near-field communications is provided that may include receiving a signal including an unmodulated carrier frequency, locking onto the unmodulated carrier frequency, and recovering a data clock frequency from the unmodulated carrier frequency based on a relationship between the data clock frequency and the unmodulated carrier frequency.

Abstract: A near field communications apparatus comprising a signal source, a transmit antenna and means for detecting a change in the input impedance of the transmit antenna to detect the presence of a device which is compatible with the apparatus.

Abstract: The present application relates to a near field communications (NFC) reader having a power amplifier which has an output that connects to an input terminal of an antenna by means of an antenna filter made up of one or more series resistors and one or more series capacitors. The NFC reader includes means for adjusting the Q factor of the antenna so as to increase the available transmit bandwidth and/or improve the efficiency of the reader. The means for adjusting the Q factor of the antenna may be, for example, a variable resistive component or one or more switches.

Abstract: A location system that employs multiple magnetic transmitters that provide magnetic fields modulated with respectively different identifying signals. A magnetic receiver extracts the identifying signal from the modulated magnetic field to determine its location. The magnetic transmitters may be configured as magnetic signal sources including magnetic pseudolites. The identifying signals are repeated at predetermined intervals such that the magnetic receiver accumulates the repeated identifying signals to provide processing gain.

Abstract: The present application relates to a transceiver for use in a communications system that uses magnetic field induction to transmit data, the transceiver having an amplifier for driving an antenna, the amplifier forming, with a capacitance and a resistance connected in parallel with the antenna, a parallel resonant circuit. The resistance value of the resistance is adjustable, to permit adjustment of the loaded quality factor of the parallel resonant circuit. The transceiver includes a processing unit configured to determine the signal to noise ratio (SNR) of a signal received by the transceiver, and based on this SNR select a modulation scheme to apply to a data signal to be transmitted by the transceiver. The value of the resistance is adjusted to a level at which the loaded quality factor of the parallel resonant circuit is able to support the bandwidth and data rate required by the selected modulation scheme.

Abstract: The present application relates to an antenna for wireless charging, the antenna comprising a coil having a fixed inductance and a fixed area, such that the antenna is operable in a frequency range of 100 kHz to 13.56 MHz.

Abstract: The present application relates to a near field communications (NFC) transmitter (10) that is configured to modulate a carrier signal with a data signal using a quadrature modulator (12). A delay is introduced into the data signal, and this delayed version of the data signal is input to the input ports of the quadrature modulator (12). The resulting I and Q signals are combined to generate an output signal that is modulated in both amplitude and phase. An NFC receiver receiving the signal transmitted by the transmitter (10) is able to recover the data signal even when the amplitude of the received signal is greatly compressed, as the phase modulation of the transmitted signal is unaffected by the compression associated with power harvesting.

Abstract: Methods and apparatus in a near-field communication system, in which a modulated signal received in a Reader is clipped by applying upper and lower clip levels. After clipping, the modulated part of the signal corresponds to a greater portion of the overall signal, and thus the requirements placed on an analog-to-digital converter for the clipped signal are reduced. In a first mode of operation, prior to or at the start of reception of the load-modulated signal, the clip levels may be set in a feedforward manner on the basis of preset values or a detected change in the overall signal; in a second mode of operation, once the clipped signal is available, the clip levels may be set in a feedback manner on the basis of the clipped signal.