Described are power line communication (PLC) systems, devices and techniques which are reliable and suitable for use in control applications which can operate with relatively low data rates while complying with governing regulatory rules. Such systems, devices and techniques enable demand-side management of electrical loads in a building or facility or other environment.

Provided is a device comprising a frequency demodulator and an amplitude demodulator. The device is configured to use, in a first mode, both the frequency demodulator and the amplitude demodulator in parallel and to activate a radio frequency identification (RFID) card mode or a Qi charger mode based on results provided by said demodulators.

An optical signal transmission method according to an embodiment of the disclosure is an optical signal transmission method in which a processor performs at least part of each operation, and may include an operation of receiving a data stream, an operation of separating at least part of the data stream into three channels, modulating the separated data streams respectively according to M-ary frequency shift keying (M-FSK) scheme so as to produce an FSK modulated signal, an operation of combining a plurality of FSK modulated signals modulated respectively in the three channels, and producing a color modulated signal according to a bit-color mapping table set in advance, and an operation of transmitting the color modulated signal by controlling a light source of the same optical channel based on the color modulated signal.

An automatic gain control method, sensor (700), and radio device (900); by means of using the saturation information of a test echo unit to adjust the gain coefficient of a transmitting and receiving link, it is ensured that the received signal power used for target detection is located within a rated threshold range, further improving the accuracy of sensor (700) target detection, and avoiding defects such as missed detection, false detection, and even blindness.

An automatic gain control method, sensor (700), and radio device (900); by means of using the saturation information of a test echo unit to adjust the gain coefficient of a transmitting and receiving link, it is ensured that the received signal power used for target detection is located within a rated threshold range, further improving the accuracy of sensor (700) target detection, and avoiding defects such as missed detection, false detection, and even blindness.

In an embodiment a device includes a first circuit and a second circuit, wherein the first circuit is configured to generate a fourth signal and a fifth signal by applying the phase shift respectively to a first signal and to a second signal and deliver a sixth signal corresponding to a sampling over one bit of the fourth signal, a seventh signal corresponding to a sampling over one bit of the fifth signal, an eighth signal corresponding to a sampling over one bit of a difference between the fourth and fifth signals, and a ninth signal corresponding to a sampling over one bit of a sum between the fourth and fifth signals, wherein the second circuit is configured to receive the sixth, seventh, eighth, and ninth signals and determine, during a first phase where the first and second signals are representative of a first known symbol of a QPSK constellation, a state of a first bit from among a first state and a second state based on the eighth and ninth signals.

An audio data transmission method includes encapsulating, based on a physical layer frame header, a protocol data unit (PDU) including audio data, to obtain an audio data packet, where the physical layer frame header is modulated using a first digital modulation scheme, the PDU is modulated using a second digital modulation scheme, a value of a modulation rate of the first digital modulation scheme is equal to a value of a data transmission rate, and a value of a modulation rate of the second digital modulation scheme is less than the value of the data transmission rate, and sending the audio data packet on a BLUETOOTH low energy (BLE) physical channel at the data transmission rate.

An audio data transmission method includes encapsulating, based on a physical layer frame header, a protocol data unit (PDU) including audio data, to obtain an audio data packet, where the physical layer frame header is modulated using a first digital modulation scheme, the PDU is modulated using a second digital modulation scheme, a value of a modulation rate of the first digital modulation scheme is equal to a value of a data transmission rate, and a value of a modulation rate of the second digital modulation scheme is less than the value of the data transmission rate, and sending the audio data packet on a BLUETOOTH low energy (BLE) physical channel at the data transmission rate.

A method and an apparatus for transmitting a wakeup packet in a wireless LAN system are proposed. Specifically, a transmitter generates a wakeup packet by applying an OOK scheme. The transmitter transmits the wakeup packet to a receiver via an 80 MHz channel. The 80 MHz channel includes first to fourth subchannels. If some of the first to fourth subchannels are busy or there are no pending wakeup packets for the receiver in some of the subchannels, some of the subchannels are punctured. The wakeup packet is transmitted via the remaining subchannels of the first to fourth subchannels. Each of the first to fourth subchannels is a 20 MHz channel.

A method and an apparatus for transmitting a wakeup packet in a wireless LAN system are proposed. Specifically, a transmitter generates a wakeup packet by applying an OOK scheme. The transmitter transmits the wakeup packet to a receiver via an 80 MHz channel. The 80 MHz channel includes first to fourth subchannels. If some of the first to fourth subchannels are busy or there are no pending wakeup packets for the receiver in some of the subchannels, some of the subchannels are punctured. The wakeup packet is transmitted via the remaining subchannels of the first to fourth subchannels. Each of the first to fourth subchannels is a 20 MHz channel.