Disclosed are a pulse radar apparatus and an operating method of the pulse radar apparatus, the pulse radar apparatus including a transmitter configured to receive a reference signal as a transmission clock signal, and transmit a transmission pulse to an object based on the transmission clock signal, a negative feedback loop configured to delay the reference signal and output the delayed reference signal as a reception clock signal, and a receiver configured to restore, based on the reception clock signal, a reflection pulse received in response to the transmission pulse being reflected from the object, wherein the negative feedback loop is configured to generate a delay control signal using the reference signal and a predetermined waveform signal generated by a waveform generator, delay the reference signal based on the delay control signal, and adjust the delay control signal by controlling the waveform generator to change the predetermined waveform signal.

A method includes receiving from multiple transducers respective signals including reflections of a transmitted signal from a target. An image of the target is produced irrespective of sparsity of the received signals, by computing transducer-specific frequency-domain coefficients for each of the received signals, deriving, from the transducer-specific frequency-domain coefficients, beamforming frequency-domain coefficients of a beamformed signal in which the reflections received from a selected direction relative to the transducers are emphasized, and reconstructing the image of the target at the selected direction based on the beamforming frequency-domain coefficients.

A radar signal transmitter transmits first and second radar signals at different first and second frequencies. A radar receiver receives reflected radar signals and generates receive signals indicative of the reflected radar signals. A first receive signal is indicative of a first reflected radar signal generated by reflection of the first transmitted radar signal, and a second receive signal is indicative of a second reflected radar signal generated by reflection of the second transmitted radar signal. A processor receives the first and second receive signals and computes a difference between the first and second receive signals to generate a difference signal. The processor processes the difference signal to provide radar information for the region, the processor adjusting at least one of amplitude and phase of at least one of the first and second receive signals such that the difference is optimized at a preselected range from the receiver.

Various examples of methods and systems are provided for generation of correlated finite alphabet waveforms using Gaussian random variables in, e.g., radar and communication applications. In one example, a method includes mapping an input signal comprising Gaussian random variables (RVs) onto finite-alphabet non-constant-envelope (FANCE) symbols using a predetermined mapping function, and transmitting FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The FANCE waveforms can be based upon the mapping of the Gaussian RVs onto the FANCE symbols. In another example, a system includes a memory unit that can store a plurality of digital bit streams corresponding to FANCE symbols and a front end unit that can transmit FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The system can include a processing unit that can encode the input signal and/or determine the mapping function.

A method for determining parameters of a finite impulse response pulse compression filter, implemented by a multi-channel radar comprises: a step Etp10 of transmitting a calibration signal and of acquiring this calibration signal after propagation through the transmission channel, a step Etp20 of injecting the signal acquired, at the input of each of the reception channels, a step Etp30 of measuring the signal at the output of each reception channel, a step Etp40 of calculating the transfer function of the matched filters on the basis of the signals at the output of the reception channels, a step Etp50 of measuring the value of the average power at the output of the various reception channels and of calculating the relative gains between each of the reception channels and a predetermined reception channel on the basis of the measured values of average powers.

A method for determining parameters of a finite impulse response pulse compression filter, implemented by a multi-channel radar comprises: a step Etp10 of transmitting a calibration signal and of acquiring this calibration signal after propagation through the transmission channel, a step Etp20 of injecting the signal acquired, at the input of each of the reception channels, a step Etp30 of measuring the signal at the output of each reception channel, a step Etp40 of calculating the transfer function of the matched filters on the basis of the signals at the output of the reception channels, a step Etp50 of measuring the value of the average power at the output of the various reception channels and of calculating the relative gains between each of the reception channels and a predetermined reception channel on the basis of the measured values of average powers.

A light wave distance meter according to the present invention includes: a light-emitting element that emits a distance measurement light; a light-receiving element that outputs a light-receiving signal; a frequency conversion unit that includes a bandpass filter; an arithmetic control unit that computes a distance value to a measurement object; a signal generator that generates a signal having a predetermined frequency; a waveform conversion unit that generates a waveform conversion signal; pulse generators that generate pulse signals by pulsating the signal having a predetermined frequency so as to have a waveform profile of a signal constituted of desired frequency components on the basis of the signal output from the signal generator and the waveform conversion signal output from the waveform conversion unit; and a drive unit that emits the distance measurement light based on the pulse signals.

An image generating device for a radar includes a receiving module configured to receive a radar signal from an antenna and process the radar signal to generate an echo, an edge image generator configured to generate an edge echo image based on the echo acquired at a first time instance, a projected image generator configured to generate a projected echo image based on the echo acquired at a second time instance, and a superimposition generator configured to superimpose the edge echo image on the projected echo image based on the first and second time instances, to generate a superimposed echo image.

An image generating device for a radar includes a receiving module configured to receive a radar signal from an antenna and process the radar signal to generate an echo, an edge image generator configured to generate an edge echo image based on the echo acquired at a first time instance, a projected image generator configured to generate a projected echo image based on the echo acquired at a second time instance, and a superimposition generator configured to superimpose the edge echo image on the projected echo image based on the first and second time instances, to generate a superimposed echo image.

The transmission unit generates a transmission signal obtained by multiplying a linearly FM-modulated pulse signal by a first window function. The pulse compression unit divides a signal, which is obtained by multiplying a first reference signal obtained by multiplying the pulse signal by a second window function different from the first window function, by a complex conjugate part of a second reference signal obtained by multiplying the pulse signal by a third window function, which is a function independent of the second window function, by a complex conjugate part of the transmission signal, and uses this as a reference signal. Then, the pulse compression unit performs pulse compression on the received signal using the reference signal.