A system for measuring phase coherence between two modulated radio frequency signals comprises at least two measurement receivers coupled with each other and a processing module assigned to the at least two measurement receivers. Each of the at least two measurement receivers is configured to acquire a radio frequency signal and to convert the respective radio frequency signal acquired into digital samples. The processing module is configured to receive the digital samples and to transform the digital samples into a frequency domain to obtain a respective transformed dataset assigned to each measurement receiver. The processing module is also configured to calculate a phase in dependency of the frequency from the respective transformed dataset. Moreover, the processing module is configured to determine a phase difference over frequency based on the transformed datasets. Further, a method of measuring phase coherence between two modulated radio frequency signals is described.

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.

Frequency analysis of each of a plurality of reception antennas and each of reception signals received by the plurality of reception antennas is performed, a power spectrum is calculated for each of the reception antennas, a standard deviation indicating a degree of conformity in a peak of the power spectrum among the plurality of reception antennas is calculated, the power spectra are corrected with use of the standard deviation, a peak is detected based on the corrected power spectra, and a target object is detected based on the detected peak.

In a life detection method of the present invention, a signal transceiver is configured to transmit a transmission signal to an area and receive a reflected signal from the area as a detection signal, a demodulator coupled to the signal transceiver is configured to receive and demodulate the detection signal to output a demodulated signal, a compute element coupled to the demodulator is configured to receive the demodulated signal and compute a RMS value of the demodulated signal, and a determination element coupled to the compute element is configured to receive the RMS value of the demodulated signal and determine whether having a living body within the area according to the RMS value and a RMS threshold value.

A transceiver having quantization noise compensation is disclosed. The transceiver includes transmitter and receiver circuits. The transmitter is configured to receive and quantize a digital signal to generate a quantized signal. The quantized signal is then converted into an analog transmit signal and transmitted as a wireless signal. The receiver circuit is configured to receive a reflected version of the wireless signal and generate an analog receive signal based thereon. The analog receive signal is converted into a digital receive signal. Thereafter, the receiver cancels quantization noise from the digital receive signal to produce a digital output signal that can be utilized for further processing.

According to a first aspect, a radar system with blockage detection is provided. The radar system includes a first antenna for receiving first signals and a second antenna for receiving second signals. Input circuitry processes the first signals to generate first input signals and processes the second signals to generate second input signals. A processor computes a correlation between the first input signals and the second input signals, determines a correlation variance related to variation in the correlation, and generates a determination as to whether the radar system is blocked using the correlation variance.

Embodiments described herein can address these and other issues by using radar machine learning to address the radio frequency (RF) to perform object identification, including facial recognition. In particular, embodiments may obtain IQ samples by transmitting and receiving a plurality of data packets with a respective plurality of transmitter antenna elements and receiver antenna elements. I/Q samples indicative of a channel impulse responses of an identification region obtained from the transmission and reception of the plurality of data packets may then be used to identify, with an autoencoder, a physical object in the identification region.

A method of determining a distance between a radio frequency device and a target is disclosed in which the radio frequency device receives a radio frequency signal from the target. The method comprises determining a time domain channel response from the received radio frequency signal, determining an amplitude of a largest peak in the time domain channel response, determining an amplitude of a second, earlier, peak in the time domain channel response, comparing the second peak amplitude to a threshold based on the largest peak amplitude, identifying the largest peak as a shortest path peak if the second peak amplitude is less than the threshold, identifying the second peak as a shortest path peak if the second peak amplitude is greater than the threshold, and calculating the distance between the radio frequency device and the target based on a time corresponding to the shortest path peak.

A method for facilitating robust radar detection comprises generating a radar signal in a digital domain along at least one transmission path, the radar signal comprises a number of M periodic repetitions of a code sequence with a length Lc, multiplied with a progressive phase rotation e.sup.j.Math.π/K.Math.n, where Lc and M are integers, K is an integer or a non-integer, and n is a discrete time index corresponding to a code rate. The method further comprises generating a process input signal in the digital domain along at least one receiving path from a digitized reflection signal corresponding to the radar signal by multiplying the digitized reflection signal with a progressive phase rotation e.sup.−j.Math.π/K.Math.n. In this context, K is defined such that a ratio Lc/2.Math.K is a non-integer, and M is defined such that a ratio Lc.Math.M/2.Math.K is an integer.

Health signal monitoring using continuous wave microwave signals is often affected by phase wrapping and null point detection issues. The disclosure herein generally relates to health monitoring, and, more particularly, to a method and a monitoring system for health monitoring using Amplitude Modulated Continuous Wave (AMCW) microwave signals. In this design of the monitoring system, the AMCW microwave signal comprises of a carrier signal and a modulating signal. The modulating signal is used for measuring heart rate and breathing rate of a subject, while the carrier signal is used to tune antenna size in the monitoring system. As the probing wavelength and the antenna size are independent of each other in this design of the monitoring system, the probing wavelength can be adjusted such that effect of the phase wrapping can be minimized. The system addresses the null point measurement problem by quadrature modulating the modulating signal.