Abstract: A method of determining range and velocity information of a target in a light detection and ranging (LiDAR) system, includes determining a set of signal power density spectrums in a frequency domain based on an optical signal returned from a target, wherein a number of the set of signal power density spectrums is determined based on an expected mirror Doppler shift associated with the optical signal returned from the target. The method further includes averaging the set of signal power density spectrums to generate a compensated signal power density spectrum and detecting a peak value in the compensated signal power density spectrum to determine range and velocity information related to a target based on a corresponding frequency of the peak value of compensated signal power density spectrum.

Abstract: A frequency modulated continuous wave (FMCW) light detection and ranging (LIDAR) system includes a processor and a memory. The memory stores instructions that, when executed by the processor, cause the system to: generate subbands in a frequency domain based on a range-dependent time domain baseband signal, classify each subband into a subband type, select processing parameters for each subband based on the respective subband type, and process each of the subbands using the selected processing parameters for the subband.

Abstract: A first signal at a first channel and a second signal at a second channel are received at the LiDAR system. A frequency of a crosstalk signal in a detection of the second signal is determined based on the first signal. An intensity of the crosstalk signal is determined based on the intensity of the first signal. Provided the intensity of the crosstalk signal is in a detectable range, the crosstalk signal is excluded from the detection of the second signal to produce a corrected second signal, to extract the at least one of range or velocity information related to a target based on the corrected second signal.

Abstract: A method of operating a LIDAR system includes determining, from a first signal in a frequency domain, signal intensities for a first plurality of frequencies around a first peak frequency, determining, from a second signal in the frequency domain, signal intensities for a second plurality of frequencies around a second peak frequency, and performing a convolution of the signal intensities for the first plurality of frequencies and the signal intensities for the second plurality of frequencies. The method further includes performing a correction of the first peak frequency based on a third peak frequency identified from the convolution to obtain a corrected first peak frequency and determining range and velocity information associated with a target based on the corrected first peak frequency.

Abstract: The LiDAR system includes a coherent receiver disposed in a reference path. The coherent receiver includes a 90° optical hybrid to receive a portion of an optical beam along the reference path and a local oscillator (LO) signal to generate multiple output signals. The coherent receiver includes a first photodetector to receive a first and a second output signal to generate a first mixed signal, and a second photodetector to receive a third and a fourth output signal to generate a second mixed signal. The LiDAR system further includes a processor to combine the first mixed signal and the second mixed signal to generate a combined reference signal. A negative image of a reference beat frequency signal produced by the optical beam and the LO signal is suppressed to estimate a phase noise of the optical source to determine at least one of range or velocity information of the target.

Abstract: A light detection and ranging (LIDAR) system to transmit optical beams including at least up-chirp frequency and at least one down-chirp frequency toward targets in a field of view of the LIDAR system and receive returned signals of the up-chirp and the down-chirp as reflected from the targets. The LIDAR system may determine multiple frequency peaks associated with the target based on the returned signals. Upon determining that at least one of the multiple frequency peaks is within one or more sets of frequency ranges, the LIDAR system may combine an in-phase signal and a quadrature signal of the returned signals to generate a complex signal that enables determining whether the at least one of the multiple frequency peaks is associated with ghosting. Upon determining to be free from ghosting, the LIDAR system determines one or more of the target location, a target velocity, and a target reflectivity.

Abstract: A light detection and ranging (LIDAR) system includes an automatic gain control (AGC) unit to reduce the dynamic range, reducing processing power and saving circuit area and cost. The system detects a return beam of a light signal transmitted to a target, having a first dynamic range in a time domain. An analog to digital converter (ADC) generates a digital signal based on the return beam. A processor can perform time domain processing on the digital signal, convert the digital signal from the time domain to a frequency domain, and perform frequency domain processing on the digital signal in the frequency domain. The AGC unit can measure a power of the return beam, and apply variable gain in the frequency domain to reduce a dynamic range of the return beam to a second dynamic range lower than the first dynamic range.

Abstract: A light detection and ranging (LIDAR) system has an active modulator to modulate a light signal from an optical source with a low-power mode at a section of a sweep signal to generate a pulsed light signal transmitted towards a target. The LIDAR system has a photodetector to receive a return beam from the target with an amplitude modulated (AM) signal portion and a frequency modulated (FM) signal portion. The LIDAR system determines a target range value for the target based on the AM signal portion and determines a target velocity value for the target based on the FM signal portion.

Abstract: A method transmits an optical beam towards a target within a field of view (FOV) according to a scan pattern that includes scan lines and a pilot line. The optical beam is modulated during the scan lines at a first chirp rate and modulated during the pilot line at a second chirp rate. The method then receives a returned optical beam, which is produced in response to transmitting the optical beam towards the target. Based on the returned optical beam, the method then generates a point cloud that includes data points related to the target.

Abstract: A frequency modulated continuous wave (FMCW) light detection and ranging (LIDAR) system includes an automatic gain control (AGC) unit to reduce the dynamic range of the signal to be processed. The system detects a return beam of a light signal transmitted to a target, having a first dynamic range in a time domain. The AGC unit can measure a power of the return beam, and apply variable gain in the time domain to reduce a dynamic range of the return beam to a lower dynamic. An analog to digital converter (ADC) generates a digital signal based on the return beam. A processor can perform time domain processing on the digital signal, convert the digital signal from the time domain to a frequency domain, and perform frequency domain processing on the digital signal in the frequency domain.

Abstract: A light detection and ranging (LIDAR) system has a modulator to modulate a light signal from an optical source with a low-power mode at a section of a sweep signal to generate a pulsed light signal transmitted towards a target. The LIDAR system has a photodetector to receive a return beam from the target with an amplitude modulated (AM) signal portion and a frequency modulated (FM) signal portion. The LIDAR system processes the return beam with in-phase/quadrature (I/Q) detection to extract the AM signal portion and the FM signal portion. The system determines a range value and a velocity value for the target based on the extracted AM signal portion and the extracted FM signal portion.

Abstract: A number of measurements of an input spectrum is determined based on a scan mirror speed of the LiDAR system and a predetermined accuracy threshold in the number of measurements of the input spectrum. A set of signals are sampled at the LiDAR system and the set of signals are converted to a frequency domain to generate a set of sampled signals in the frequency domain. The set of signals are received consecutively over time. A set of first functions are created based on the set of sampled signals. The set of first functions are averaged to generate a second function. The second function represents a power spectrum density estimate of the set of signals. A peak value of the second function is detected to determine range and velocity information related to a target based on a corresponding frequency of the peak value of the second function.

Abstract: A light detection and ranging (LIDAR) system, includes a memory, and a processor, operatively coupled to the memory, to identify an obstruction of the LIDAR system based on a comparison of a frequency of an energy peak generated from a return signal to a threshold frequency and mitigate the obstruction.

Abstract: A light detection and ranging (LIDAR) technique that includes dividing the field of view into a grid including a plurality of cells. The technique also includes transmitting an optical beam and generating a baseband signal based on a returned optical beam. The baseband signal includes a plurality of peaks corresponding with up-chirps and down-chirps in the transmitted signal. The technique also includes generating a negative image of the second peak to generate a third peak, computing, using the first peak and the second peak, a first point having a first velocity and a first location within a first cell, and computing, using the first peak and the third peak, a second point having a second velocity and a second location within a second cell. The technique also includes determining whether to accept the first point or the second point for inclusion in a point cloud.

Abstract: A first signal is sampled at the LiDAR system to produce a first set of samples around a first detected frequency peak related to the first signal. A second signal is sampled at the LiDAR system to produce a second set of samples around a second detected frequency peak related to the second signal. A first function based on the first set of samples and a second function based on the second set of samples are convolved to produce a third function. At least one of the first signal or the second signal is refined to produce at least one of a first refined signal or a second refined signal based on the third function. Range and velocity information is extracted related to a target based on the at least one of the first refined signal or the second refined signal.

Abstract: A method transmits a first optical beam towards targets within a field of view (FOV). The first optical beam is modulated at a first chirp rate for a first set of scan lines that correspond to a first distance of the targets. The method identifies conditions based on the FOV to calculate a second chirp rate, and generates a scan pattern by transmitting a second optical beam towards the targets within the FOV. The second optical beam is modulated at the second chirp rate for a second set of scan lines that corresponds to a second distance of the one or more targets. The method generates, based on the first and second optical beams, the point cloud that includes multiple data points related to the target in which some of the data points are related to a first target and other data points are related to a second target.

Abstract: A light detection and ranging (LIDAR) system to transmit an optical beam toward a target and receive a returned optical beam. The optical beam includes an up-chirp frequency and a down-chirp frequency, and is modulated to have phase non-linearities. The LIDAR system generates a baseband signal from the returned optical beam, which includes a plurality of peaks corresponding with the up-chirp frequency and the down-chirp frequency. The LIDAR system identifies a first true peak in the baseband signal, and identifies a second true peak in the baseband signal based, at least in part, on a spectral shape of the second true peak caused by the phase non-linearities. The LIDAR system is to determine the location of the target using the first true peak and the second true peak.

Abstract: A method transmits a first optical beam towards targets within a field of view (FOV). The first optical beam is modulated at a first chirp rate for a first set of scan lines that correspond to a first distance of the targets. The method identifies conditions based on the FOV to calculate a second chirp rate, and generates a scan pattern by transmitting a second optical beam towards the targets within the FOV. The second optical beam is modulated at the second chirp rate for a second set of scan lines that corresponds to a second distance of the one or more targets. The method generates, based on the first and second optical beams, the point cloud that includes multiple data points related to the target in which some of the data points are related to a first target and other data points are related to a second target.

Abstract: The LiDAR system includes a coherent receiver disposed in a reference path. The coherent receiver includes a 90° optical hybrid to receive a portion of an optical beam along the reference path and a local oscillator (LO) signal to generate multiple output signals. The coherent receiver includes a first photodetector to receive a first and a second output signal to generate a first mixed signal, and a second photodetector to receive a third and a fourth output signal to generate a second mixed signal. The LiDAR system further includes a processor to combine the first mixed signal and the second mixed signal to generate a combined reference signal. A negative image of a reference beat frequency signal produced by the optical beam and the LO signal is suppressed to estimate a phase noise of the optical source to determine at least one of range or velocity information of the target.

Abstract: A light detection and ranging (LIDAR) system, includes an optical source to generate a frequency modulated continuous wave (FMCW) optical beam, a memory, and a processor, operatively coupled to the memory, to identify energy peaks in a frequency domain of a range-dependent baseband signal that corresponds to a return signal from a reflection of the FMCW optical beam and identify an obstruction of the LIDAR system based on a comparison of a frequency of the energy peaks to a threshold frequency.