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: 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 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 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 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 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 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.

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: receive samples of a range-dependent time domain baseband signal; assemble the samples into sample blocks in the time domain; convert the sample blocks from the time domain to the frequency domain; generate subbands in the frequency domain from converted sample blocks; classify the subbands into a plurality of subband types based on subband typing criteria; select subband processing parameters for each of the subbands based on respective ones of the plurality of subband types; and process each of the subbands using the selected subband processing parameters for the subband.

Abstract: A method to compensate for phase impairments in a light detection and ranging (LIDAR) system includes estimating one or more phase impairments in the LIDAR system using a digitally-sampled reference signal to produce one or more estimated phase impairments and performing one or more corrections on one or more phase impairments in a digitally-sampled target signal based on the one or more estimated phase impairments.

Abstract: A method to select multiple returns in a light detection and ranging (LIDAR) system includes thresholding a frequency domain waveform to identify a number of peaks above a threshold level. After thresholding, a primary peak selection is applied to identify a primary peak. After identifying a primary peak, a secondary peak selection is applied to a portion of the frequency domain waveform outside a guard-band area to identify a secondary peak.

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 set of POIs of a point cloud are received at a first filter, where each POI of the set of POIs comprises one or more points. Each POI of the set of POIs is filtered. A set of neighborhood points of a POI is selected. A metric for the set of neighborhood points is computed based on a property of the set of neighborhood points and the POI, wherein the property comprises a velocity. Based on the metric, whether to accept the POI, modify the POI, reject the POI, or transmit the POI to a second filter, to extract at least one of range or velocity information related to the target is determined. Provided the POI is not accepted, modified, or rejected, the POI is transmitted to the second filter to determine whether to accept, modify, or reject the POI to extract the at least one of range or velocity information related to the target.

Abstract: A light detection and ranging (LIDAR) system transmits, towards a target, a set of chirp signals. The LIDAR system receives from the target, a set of adjusted chirp signals. The LIDAR system then determines, based on the set of adjusted chirp signals, a degree of ghosting mitigation to compensate for a ghost target appearing in a point cloud at a location where no real target exists.

Abstract: A method to compensate for phase impairments in a light detection and ranging (LIDAR) system includes transmitting a first optical beam towards a target, receiving a second optical beam from the target to produce a received optical beam; and generating a digitally-sampled target signal using a local oscillator (LO) beam, a first photo-detector and the received optical beam. The method also includes generating a digitally-sampled reference signal using a reference beam transmitted through a fiber delay device and a second photo-detector, and estimating one or more phase impairments in the LiDAR system using the digitally-sampled reference signal to produce one or more estimated phase impairments. The method also includes performing a first correction on a first phase impairment introduced into the digitally-sampled target signal by the LO beam; performing a second correction on a second phase impairment introduced into the digitally-sampled target signal by the received optical beam.

Abstract: A method of compensation in a light detection and ranging (LIDAR) system. The method includes applying a first frequency shift to a target signal to compensate for doppler shift in the target signal and performing a phase impairment correction on the target signal to produce a corrected target signal. The method further includes undoing the first frequency shift on the corrected target signal.