Methods, systems, and devices for wireless communication are described. A communication device (e.g., a vehicle) in wireless communications system (e.g., a cellular-vehicle-to-everything (V2X) system) may support adaptive radar transmissions based on information received in a public safety message. The communication device may use information included in the public safety message to adapt radar transmissions to enable timely detection of vulnerable road users (VRUs). In some examples, based on a location and a velocity estimate provided in the public safety message, the communication device may adjust the radar transmissions to experience a trade-off between range and velocity estimation performance. Additionally or alternatively, based on positional accuracy estimates provided in the public safety message, the communication device may adjust the radar transmissions to improve beamforming. By adapting the radar transmissions, the communication device may experience low latency and high reliability for VRU collision warnings in the C-V2X system.

A detection method using a frequency modulated continuous wave, a radar, and a computer-readable storage medium. The method includes: emitting a detection wave to detect a target object, where the detection wave is a nonlinear frequency sweep modulated signal; receiving an echo of the detection wave reflected by the target object; obtaining an actual beat frequency signal according to the echo and the detection wave; and obtaining a distance and/or velocity of the target object according to the actual beat frequency signal. By the method, the decoupling and separation of distance/velocity information may be completed in a single cycle. The decoupling and separation of a distance/velocity can be completed within a single frequency sweep cycle, and a detection probability of a system is kept from deteriorating.

A radar system, apparatus, architecture, and method are provided with a transmitter that produces a plurality of distinct FanTOM signals that are transmitted as N RF-encoded transmit signals in an overlapped fashion such that the pulse repetition interval and frame length are kept short; a receiver that processes target return signals reflected from the N RF-encoded transmit signals with a mixer to produce an IF signal which is filtered with one or more notch filters clocked with a sampling clock frequency to control harmonic notch frequencies to suppress transmitter spill-over and close-in self-clutter interference, thereby producing a filtered IF signal that is converted to a digital signal with an analog-to-digital converter that is clocked with the sampling clock frequency; and a radar processor that processes the digital signal to generate a range spectrum comprising N segments that correspond, respectively, to the N RF-encoded transmit signals.

A vehicle radar sensor utilizes Frequency Modulated Continuous Wave (FMCW) radar signals that incorporate non-uniform FMCW chirps having chirp profiles that differ from one another to sense one or more parameters of one or more objects in a field of view of the radar sensor. The chirp profiles may differ from one another in various manners, e.g., based on starting frequency, repetition interval, duration and/or slope, and among other advantages, may be used to enhance sensing of various parameters such as range, Doppler/velocity and/or angle.

Various examples for multi-tone continuous wave detection and ranging are disclosed herein. In some embodiments, an initial signal is generated using initial radio frequency (RF) tones, and is emitted as a multi-tone continuous wave signal. The initial signal is reflected from a target and received as a reflected signal. Resultant RF tones, including a frequency, a phase and a power, are determined from the reflected signal in a frequency domain. A frequency-domain sinusoidal wave is fitted to the resultant RF tones in the frequency domain, and a distance to the target is determined using a modulation of the frequency-domain sinusoidal wave. A phase processing algorithm is applied to generate the target distance and speed by triangulating the range information encoded in the backscattered RF tones.

A method for controlling a radar apparatus that detects an object using frequency modulation includes: performing first reception of a radio wave in a state where transmission of a radio wave for detecting the object is stopped, to obtain a first reception signal; performing second reception of a radio wave in a state where the transmission of the radio wave is stopped, to obtain a second reception signal, after the performing of the first reception; acquiring a strength of a difference signal between the first reception signal and the second reception signal; comparing the strength with a threshold value; and starting the transmission of the radio wave in a case where the strength is equal to or less than the first threshold value in the comparison.

In one aspect, a system for obtaining dielectric properties of an object is disclosed, which comprises a plurality of transceivers for generating radiation in the microwave or millimeter-wave region of the electromagnetic spectrum. The transceivers are positioned in spatially fixed relationships relative to one another. The system further includes a controller for selectively activating the transceivers for irradiating at least a portion of the object and detecting at least a portion of the radiation reflected from said portion of the object in response to the irradiation, where each of the activated transceivers generates a signal in response to detection of the reflected radiation. The reflected signals are analyzed to determine a plurality of reflectivity coefficients corresponding to different discrete locations of the object, and the reflectivity coefficients are used to determine the complex permittivity of the discrete locations.

An apparatus for emitting electromagnetic radiation and receiving partial radiation reflected by objects, and determines the instantaneous performance of its system detection. The apparatus includes a device for emitting a frequency-modulated transmit signal that has at least two signal sequences which have ramps, each succeeding one another in the frequency characteristic, with gaps in between, the signal sequences being interleaved with each other with a predetermined time offset so that in each case a first ramp of each of the signal sequences is output before a second ramp of one of the at least two signal sequences is output. The apparatus includes a mixer, an analog-to-digital converter, a transform device, and a device for detecting phase noise. The phase changes of the receive signals are compared over all two-dimensional spectra to a precalculated model, and the cause of the phase noise is ascertained with the aid of predetermined criteria.

A method of determining a filling level of a product in a tank, comprising the steps of: generating an electromagnetic transmit signal exhibiting a measurement sweep across a time series of piece-wise constant frequencies being within a measurement frequency range starting at a first frequency, and ending at a second frequency higher than the first frequency, a difference between frequencies in each pair of adjacent frequencies in the frequency range being equal to the first frequency; guiding the transmit signal towards and into the product in the tank; guiding an electromagnetic reflection signal back towards the transceiver; mixing the reflection signal with an electromagnetic reference signal, resulting in a mixer output indicative of a difference between the reflection signal and the reference signal; forming a measurement signal based on the mixer output; and determining the filling level based on the measurement signal.

Apparatus and associated methods relate to enabling a radar system to use different sensing mechanisms to estimate a distance from a target based on different detection zones (e.g., far-field and near-field). In an illustrative example, a curve fitting method may be applied for near-field sensing, and a Fourier transform may be used for far-field sensing. A predetermined set of rules may be applied to select when to use the near-field sensing mechanism and when to use the far-field mechanism. The frequency of a target signal within a beat signal that has less than two sinusoidal cycles may be estimated with improved accuracy. Accordingly, the distance of a target that is within a predetermined distance range (e.g., two meters range for 24 GHz ISM band limitation) may be reliably estimated.