This application provides communication apparatuses and methods for signal transmission and reception, applied to, for example, backscatter communications. In an example method, a tag device receives a downlink excitation signal, where the downlink excitation signal is a linear frequency modulated signal or a multi-carrier linear frequency modulated signal. The tag device generates an uplink reflection signal according to the downlink excitation signal and uplink information. The tag device sends the uplink reflection signal to a network device. When receiving the uplink reflection signal from the tag device and receiving the downlink excitation signal, the network device performs fractional Fourier transform on the uplink reflection signal and the downlink excitation signal, to obtain an uplink frequency domain reflection signal and a downlink frequency domain excitation signal. The uplink frequency domain reflection signal and the downlink frequency domain excitation signal do not overlap each other.

A method includes providing an ensemble of distributed sensors, delivering radio frequency (RF) power to each sensor by inductive near-field coupling by a magnetic field projected by an epidermal transmit (Tx) coil, in each individual sensor, detecting a sparse binary event in its immediate environment, reporting the detected sparse binary event to an external RF receiver hub asynchronously and with low latency, and minimizing error rates due to statistical data packet collisions in asynchronous telemetry by digitally encoding each sensor according to a particular address scheme where each address is one function from an infinite set of mathematically orthogonal functions, enabling a simultaneous detection from up to ten thousand points without interference at a common receiver.

A method includes providing an ensemble of distributed sensors, delivering radio frequency (RF) power to each sensor by inductive near-field coupling by a magnetic field projected by an epidermal transmit (Tx) coil, in each individual sensor, detecting a sparse binary event in its immediate environment, reporting the detected sparse binary event to an external RF receiver hub asynchronously and with low latency, and minimizing error rates due to statistical data packet collisions in asynchronous telemetry by digitally encoding each sensor according to a particular address scheme where each address is one function from an infinite set of mathematically orthogonal functions, enabling a simultaneous detection from up to ten thousand points without interference at a common receiver.

An example according to the present specification relates to a technique for configuring a preamble in a wireless LAN (WLAN) system. A transmitting STA may generate and transmit an EHT PPDU. The EHT PPDU may comprise an L-SIG field, an RL-SIG field, a first control field, and a second control field. A result of “modulo 3 operation” for a length field value of the L-SIG field may be set to “0.” The RL-SIG field may be configured to be the same as the L-SIG field. The first control field may comprise 3-bit information on the version of a PPDU, 6-bit information on a BSS color, and 7-bit information on TXOP.

An example according to the present specification relates to a technique for configuring a preamble in a wireless LAN (WLAN) system. A transmitting STA may generate and transmit an EHT PPDU. The EHT PPDU may comprise an L-SIG field, an RL-SIG field, a first control field, and a second control field. A result of “modulo 3 operation” for a length field value of the L-SIG field may be set to “0.” The RL-SIG field may be configured to be the same as the L-SIG field. The first control field may comprise 3-bit information on the version of a PPDU, 6-bit information on a BSS color, and 7-bit information on TXOP.

This application discloses an adaptive transmission method for satellite communication. First, a receive end determines a redundancy version index; second, the receive end feeds back a redundancy version index signal to a transmit end; then, the transmit end receives the redundancy version index fed back by the receive end, and performs operations such as demodulation and decoding on the redundancy version index signal, to obtain the redundancy version index; and then, the transmit end obtains a corresponding redundancy version combination based on the obtained redundancy version index; and finally, the transmit end selects a proper diversity mode for transmission based on the obtained redundancy version combination.

A communication method includes: generating an extremely high-throughput physical layer protocol data unit (EHT PPDU), the EHT PPDU comprises a legacy physical layer preamble and a new physical layer preamble, wherein the legacy physical layer preamble comprises a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal (L-SIG) field in turn, a first field of the new physical layer preamble is a repeat of a field in the legacy physical layer preamble and is modulated by binary phase shift keying, BPSK; and sending the PPDU.

A communication circuit is disclosed. The communication circuit includes a calibration system, configured to receive clock signals respectively having first and second clock phases, and first and second duty cycles, where the calibration system is further configured to receive input data and to adjust the input data to generate adjusted data based partly on the input data and based partly on the first and second duty cycles. The communication circuit also includes a mixer, configured to receive the clock signals and to receive the adjusted data, where the mixer is configured to generate output data based on the clock signals and the adjusted data, and where a mismatch in the output data caused by the first and second duty cycles being different is reduced because of the adjustment made to the input data to generate the adjusted data.

Examples described herein include systems and methods which include wireless devices and systems with examples of mixing input data with coefficient data. For example, a computing system with processing units may mix the input data for a transmission in a radio frequency (RF) wireless domain with the coefficient data to generate output data that is representative of the transmission being processed according to the wireless protocol in the RF wireless domain. A computing device may be trained to generate coefficient data based on the operations of a wireless transceiver such that mixing input data using the coefficient data generates an approximation of the output data, as if it were processed by the wireless transceiver. Examples of systems and methods described herein may facilitate the processing of data for 5G wireless communications in a power-efficient and time-efficient manner.

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.