In a general aspect, a data communication circuit can include a transmitter configured to transmit a first digital bit stream via a first unidirectional isolation channel. The data communication circuit can further include a receiver configured to receive a second digital bit stream via a second unidirectional isolation channel. The first unidirectional isolation channel and the second unidirectional isolation channel can be defined on a common dielectric substrate. The data communication circuit can further include a crosstalk suppression circuit configured to provide at least one negative feedback signal to suppress crosstalk between the transmitter and the receiver due to parasitic capacitive coupling between the first unidirectional isolation channel and the second unidirectional isolation channel in the common dielectric substrate.

A method of wireless communication includes transmitting frames from a transponder to a reader and synchronizing between a reader carrier frequency and an active load modulation (ALM) carrier frequency within each transmitted frame. Each transmitted frame includes ALM carrier bursts generated from subcarrier modulation by binary phase shift keying (BPSK) data encoding and producing signal oscillations at a transponder antenna after each ALM carrier burst generation, The synchronizing occurs at each phase change of the data encoding when no burst is generated during a half period of the subcarrier preceding the phase change and a half period of the subcarrier following this phase change. The transponder antenna has a moderate quality factor sufficient to naturally damp the signal oscillations so that the synchronizing is performed without performing any controlled signal oscillations damping.

A method to receive telemetry messages over an RF channel, the method implemented by a system on a chip, in which a signal is received from the output of an input RF module, the received signal is offset in time and frequency wherein the signal, at first, is offset in time so that the offset magnitudes uniformly fill the length of one data bit, then, the signal is offset in frequency so that the offset magnitudes uniformly fill the space between the Fourier transform subcarriers, with the frequency offsets being independent of the time offsets; each signal processed at the preceding step is subjected to sequential Fourier transforms, with the first time element of each next transform immediately following the last element of the preceding transform; all messages are demodulated independently. The technical result consists in that messages can be received over multiple channels at multiple rates.

Embodiments of this application provide a data transmission method and apparatus. A method at a transmit end includes: obtaining a first sequence, where the first sequence includes a first sub-sequence and a second sub-sequence; mapping the first sub-sequence into K third sub-sequences based on a preset sequence group; performing differential coding and phase modulation on the second sub-sequence to obtain a fourth sequence whose length is K; obtaining K fifth sub-sequences based on the K third sub-sequences and the K fourth sub-sequences; and outputting a second sequence including the K fifth sub-sequences. A method at a receive end includes: obtaining a second sequence including K fifth sub-sequences, and detecting the K fifth sub-sequences based on a preset sequence group to obtain a first sub-sequence; and performing differential demodulation based on the first sub-sequence to obtain a second sub-sequence, so that a first sequence is determined.

A terminal device registration method and a device, where the method includes sending upstream registration window information to a terminal device, where the upstream registration window information indicates a starting position of an upstream registration window to the terminal device, receiving an upstream access signal sent by the terminal device from the starting position of the upstream registration window, where the upstream access signal includes a correlation sequence symbol and at least one orthogonal frequency division multiplexing (OFDM) symbol following the correlation sequence symbol, the correlation sequence symbol is constituted by a first sequence that meets a preset condition, and the at least one OFDM symbol modulates access information by means of differential phase modulation in a frequency domain, and performing upstream ranging according to the starting position of the upstream registration window and the correlation sequence symbol.

A method of wireless communication includes transmitting frames from a transponder to a reader and synchronizing between a reader carrier frequency and an active load modulation (ALM) carrier frequency within each transmitted frame. Each transmitted frame includes ALM carrier bursts generated from subcarrier modulation by binary phase shift keying (BPSK) data encoding and producing signal oscillations at a transponder antenna after each ALM carrier burst generation, The synchronizing occurs at each phase change of the data encoding when no burst is generated during a half period of the subcarrier preceding the phase change and a half period of the subcarrier following this phase change. The transponder antenna has a moderate quality factor sufficient to naturally damp the signal oscillations so that the synchronizing is performed without performing any controlled signal oscillations damping.

A method of wireless communication includes transmitting frames from a transponder to a reader and synchronizing between a reader carrier frequency and an active load modulation (ALM) carrier frequency within each transmitted frame. Each transmitted frame includes ALM carrier bursts generated from subcarrier modulation by binary phase shift keying (BPSK) data encoding and producing signal oscillations at a transponder antenna after each ALM carrier burst generation, The synchronizing occurs at each phase change of the data encoding when no burst is generated during a half period of the subcarrier preceding the phase change and a half period of the subcarrier following this phase change. The transponder antenna has a moderate quality factor sufficient to naturally damp the signal oscillations so that the synchronizing is performed without performing any controlled signal oscillations damping.

In a method and system for decoding a differential M-ary phase or quadrature amplitude modulated signal, the incoming signal is decoded according to a plurality of different decoding rules, wherein said plurality of decoding rules correspond to different values of a resulting frequency difference or mismatch between a signal frequency and a local oscillator reference frequency. The invention allows to increase a tolerance window for the maximal allowable frequency offset, and thus helps to speed up an initial locking process or to allow for equipment which has a lower tuning granularity.

Techniques for constant envelope phase modulation and demodulation of a wireless signal such as BLE are described. The method comprises: dividing a binary data stream to be transmitted into a plurality of groups of binary data according to a predetermined phase modulation mode, each group of binary data comprising a plurality of bits; mapping the binary data stream into a plurality of phase symbols, wherein each group of binary data is mapped into one phase symbol; modulating a phase sequence composed of the phase symbols into a phase signal using a phase waveform obtained by integrating a predetermined pulse function; and converting the phase signal into two baseband signals by means of a cosine function and a sine function respectively.

A method allowing a receiver device of a wireless communication system to receive a useful signal emitted by an emitter device. The useful signal corresponding to a signal, the phase or frequency of which is modulated by a sequence of two-state symbols corresponding to a sequence of binary data. A temporal envelope of the useful signal is detected and compared to a preset threshold value. Transitions between consecutive useful-signal symbols are detected, on the basis of the result of the comparison. A sequence of binary data is extracted from the useful signal depending on the detected transitions.