A lidar including a laser having a first frequency-modulated laser radiation and a second frequency-modulated laser radiation, a first waveguide coupled to the laser, wherein the first frequency-modulated laser radiation and the second frequency-modulated laser radiation are transmitted by the laser into the first waveguide, a second waveguide, a filter coupled between the first waveguide and the second waveguide, wherein the filter is configured to couple and pass the first frequency-modulated laser radiation through the filter to the second waveguide, and is configured to not couple or pass the second frequency-modulated laser radiation through the filter to the second waveguide, and a photodetector coupled to the second waveguide.

Systems and methods for performing listen-before-talk (LBT) operations include a first wireless communication device which schedules a data burst comprising a plurality of chirps for transmitting on a channel to a second device. The wireless communication device may perform an LBT operation on the channel between the first device and the second device to determine that the channel is available, prior to transmitting a first chirp of the plurality of chirps. The wireless communication device may transmit the first chirp on the channel responsive to performing the LBT operation.

Generated chirp pulses are modified so that they have an increased time bandwidth product to compensate for noise and/or attenuation in a communication channel. In certain circumstances, the modification alone may be inefficient so a counterbalancing modification may be applied at the receiver.

A circuit is disclosed which eliminates chirp produced within an electronic flow measurement (EFM) system. In an exemplary embodiment, relays are positioned between the EFM Rxd input and the communications device input. One relay is closed while the operate signal reaches its high state, allowing data to pass between the communications device and the EFM Rxd input. When the operate line switches to a low state, the first relay opens disrupting the data path between the communications device and the EFM Rxd input preventing data from bouncing back between the two points. The second relay may close grounding the data signal from the communications device eliminating noise from the line.

An apparatus for measuring at least one of pressure, temperature, and wind velocity of a volume of air includes a laser having a first frequency and a second frequency of radiation, a first waveguide coupled to the laser, a second waveguide, a narrowband filter coupled between the first waveguide and the second waveguide, wherein the narrowband filter is configured to redirect the first frequency to the second waveguide, and a photodetector coupled to the second waveguide, wherein the first frequency is transmitted by the first waveguide to the volume of air, scattered light is received from the volume of air, and the photodetector mixes the first frequency on the second waveguide with the received scattered light.

Generated chirp pulses are modified so that they have an increased time bandwidth product to compensate for noise and/or attenuation in a communication channel. In certain circumstances, the modification alone may be inefficient so a counterbalancing modification may be applied at the receiver.

Disclosed are a signal sending method, a signal receiving method, an electronic device and a storage medium. The signal sending method includes the following. A first transmission signal is generated, where the first transmission signal includes a communication signal and a sensing signal, and the sensing signal occupies bandwidth resources of at least two component carriers in a frequency domain; and the first transmission signal is sent.

Methods and systems are provided for spreading spectral density of pulse streams during digital to analog conversion. An example system may comprise an accumulator circuit, a bit generator circuit, and a feedback circuit. The accumulator circuit may be operable to receive a signal to be spread and generate an output based on the signal to be spread and on one or more inputs generated within the system. The bit generator circuit may be operable to input into the accumulator circuit sequences meeting at least one particular criterion. The feedback circuit may be operable to apply an adjustment to a signal corresponding to an output of the accumulator circuit to generate a feedback signal, and input the feedback signal into the accumulator circuit.

Methods and systems are provided for spreading spectral density of pulse streams during digital to analog conversion. An example system may comprise an accumulator circuit, a bit generator circuit, and a feedback circuit. The accumulator circuit may be operable to receive a signal to be spread and generate an output based on the signal to be spread and on one or more inputs generated within the system. The bit generator circuit may be operable to input into the accumulator circuit sequences meeting at least one particular criterion. The feedback circuit may be operable to apply an adjustment to a signal corresponding to an output of the accumulator circuit to generate a feedback signal, and input the feedback signal into the accumulator circuit.

Methods and systems are provided for spreading spectral density of pulse streams during digital to analog conversion. An example spreading circuit may comprise an accumulator circuit, a bit generator circuit, a comparator circuit, and an inverter circuit. The accumulator circuit may be operable to receive a signal to be spread and generate an output based on the signal to be spread and at least one other input. The bit generator circuit may be operable to input into the accumulator circuit zero-sum sequences. The comparator circuit may be operable to provide a stream of pulses based on the output of the accumulator circuit. The inverter circuit may be operable to invert output of the comparator circuit, wherein output of the inverter circuit is input into the accumulator circuit.