A method is provided for differentiating one of a plurality of unpowered NEC transmitting devices for NFC communication with a receiving device. Each NFC transmitting device has a transmitter NFC interface and an NFC communication range. A range extending device has a power source, a transmitter communication interface, a range extender antenna, and an amplifier. One of the transmitting devices is selected and the range extending device is connected to it so that the transmitter communication interface engages the transmitter NFC interface of the selected transmitting device. This action serves to establish an extended communication range for the selected NFC transmitting device. The NFC transmitting devices are then positioned at a distance from the receiving device that is within the extended communication range, but outside the communication ranges of the other NFC transmitting devices. NEC communication is then established between the selected NFC transmitting device and the receiving device.

A method of wireless communication between a transponder and a terminal includes a step, implemented by the transponder, of counting a number of error signals transmitted by the terminal.

A structure for wireless communication having a plurality of conductor layers, an insulator layer separating each of the conductor layers, and at least one connector connecting two of the conductor layers wherein an electrical resistance is reduced when an electrical signal is induced in the resonator at a predetermined frequency. The structure is capable of transmitting or receiving electrical energy and/or data at various near and far field magnetic coupling frequencies.

An embodiment device comprises a phase locked loop and a frequency locked loop having in common the same controlled oscillator. The device is firstly placed in the card emulation mode at the beginning of a communication between the contactless communication device and a contactless reader, the firstly placing comprising synchronizing within the contactless device, an ALM carrier frequency with a reader carrier frequency by operating at least the phase locked loop, and upon reception by the contactless communication device of an indication sent by the reader indicating a further communication in a peer to peer mode with the reader, the device is secondly placed in the peer to peer mode, the secondly placing including deactivating the phase locked loop and operating the frequency locked loop with a reference clock signal and a frequency set point depending on the reader carrier frequency and the frequency of the reference clock signal.

A signal transmission method and apparatus, a terminal device, a smart device, and an electronic device, are provided. The signal transmission method includes: sending, by a terminal device, a first signal to a smart device having a backscatter function, and receiving a second signal reflected by the smart device; and performing, by the terminal device when the smart device stops reflecting the second signal, channel estimation on an interference channel.

The disclosure relates to a modified NFC framing is used by a reader and selected devices during at least a part of the communication between the reader and the selected devices. The reader and the selected devices store modification rules for modifying the frames. Devices not storing those modification rules will discard the received modified frames.

There is described a method of determining a phase value for an NFC card emulating device that enables said NFC card emulating device to communicate in phase with an NFC reader device while utilizing active load modulation, wherein the NFC card emulating device comprises a card antenna and the NFC reader device comprises a reader antenna, the method comprising receiving a reader signal from the NFC reader device at the NFC card emulating device through coupling of the card antenna and the reader antenna, the reader signal comprising a subcarrier modulation; estimating a resonance frequency of a system corresponding to the coupled card antenna and reader antenna based on the received communication signal; and determining the phase value based on the estimated resonance frequency and a set of parameters that represents a predetermined reference system. Furthermore, an NFC card emulating device, an NFC system, and a computer program are described.

According to one aspect, a contactless transponder comprises a memory, an antenna configured to receive signals, a contactless interface coupled to the antenna and configured to emit memory access requests according to the signals received, a wired interface configured to receive memory access requests, an arbitration module configured to authorize access to the memory either for access requests emitted by the contactless interface or for access requests received by the wired interface, and wherein the wired interface is also configured to receive shutdown controls and transmit these shutdown controls to the arbitration module, the arbitration module being configured to be able to shut down the contactless interface when it receives a shutdown control.

An embodiment device comprises a phase locked loop and a frequency locked loop having in common the same controlled oscillator. The device is firstly placed in the card emulation mode at the beginning of a communication between the contactless communication device and a contactless reader, the firstly placing comprising synchronizing within the contactless device, an ALM carrier frequency with a reader carrier frequency by operating at least the phase locked loop, and upon reception by the contactless communication device of an indication sent by the reader indicating a further communication in a peer to peer mode with the reader, the device is secondly placed in the peer to peer mode, the secondly placing including deactivating the phase locked loop and operating the frequency locked loop with a reference clock signal and a frequency set point depending on the reader carrier frequency and the frequency of the reference clock signal.

A circuit includes an in-phase/quadrature down converter configured to be coupled to an antenna of a first NFC (near field communication) device. DC cancellation circuitry is coupled at outputs of the converter. Detection circuitry is configured to analyze DC signals output by the DC cancellation circuits to detect the presence of a second NFC device.