Embodiments include methods, systems and computer readable storage medium for a method for determining a fine direction of arrival (DOA) for a target is disclosed. The method includes receiving, by a plurality of receivers of a radar system, radar signals reflected by a target. The method further includes mitigating, by the radar system, phase shifts in the radar signals caused by a motion of the target. The method further includes determining, by the radar system, the fine DOA in response to the mitigation of phase shifts and based on the radar signals. The method further includes estimating and storing, by the radar system, a Doppler frequency based on the fine DOA.

A computer-implemented method is provided for detecting a target amidst clutter by a radar system able to transmit an electromagnetic signal, receive first and second echoes respectively from the target and the clutter, and process the echoes. The method includes determining signal convolution matrix for the target and a target return phase, clutter amplitude by spatial correlation matrix of clutter, clutter correlation matrix, receive noise power; querying whether the clutter moves as a motion condition if satisfied and as a stationary condition otherwise; calculating signal convolution matrix and target return phase from the signal convolution matrix and the target return phase for target motion; querying whether the target has range migration as a migration condition if satisfied and as a non-migration condition otherwise; and forming a target detector for the radar. The motion condition further includes calculating signal convolution matrix from clutter motion, clutter range migration matrix from the clutter motion, and interference correlation matrix. The stationary condition further includes calculating the interference correlation. The migration condition further includes calculating range migration matrix from the target motion.

A computer-implemented method is provided for detecting a target amidst clutter by a radar system able to transmit an electromagnetic signal, receive first and second echoes respectively from the target and the clutter, and process the echoes. The method includes determining signal convolution matrix for the target and a target return phase, clutter amplitude by spatial correlation matrix of clutter, clutter correlation matrix, receive noise power; querying whether the clutter moves as a motion condition if satisfied and as a stationary condition otherwise; calculating signal convolution matrix and target return phase from the signal convolution matrix and the target return phase for target motion; querying whether the target has range migration as a migration condition if satisfied and as a non-migration condition otherwise; and forming a target detector for the radar. The motion condition further includes calculating signal convolution matrix from clutter motion, clutter range migration matrix from the clutter motion, and interference correlation matrix. The stationary condition further includes calculating the interference correlation. The migration condition further includes calculating range migration matrix from the target motion.

An illustrative example embodiment of a detector device includes a plurality of transmitters and a controller that controls the transmitters to transmit respective signals defined at least in part by a sequence of 2N pulses within a period. N is an integer greater than 1. A first one of the transmitters transmits 2N first signal pulses within the period. Each of the 2N first signal pulses have a first phase. A second one of the transmitters transmits 2N second signal pulses within the period. Each of the 2N first signal pulses is simultaneous with one of the 2N second signal pulses. N second signal pulses have a phase shift of 180° relative to the first phase. Others of the second signal pulses have the first phase. The N second signal pulses having the phase shift are immediately adjacent each other in the sequence.

An illustrative example embodiment of a detector device includes a plurality of transmitters and a controller that controls the transmitters to transmit respective signals defined at least in part by a sequence of 2N pulses within a period. N is an integer greater than 1. A first one of the transmitters transmits 2N first signal pulses within the period. Each of the 2N first signal pulses have a first phase. A second one of the transmitters transmits 2N second signal pulses within the period. Each of the 2N first signal pulses is simultaneous with one of the 2N second signal pulses. N second signal pulses have a phase shift of 180° relative to the first phase. Others of the second signal pulses have the first phase. The N second signal pulses having the phase shift are immediately adjacent each other in the sequence.

A method, system and apparatus are provided for estimating characteristics of a wireless communication channel between at least two passive radio frequency (RF) nodes. Backscatter channel state information (BCSI) is measured during communication between the at least two passive RF nodes using the wireless communication channel. An RF node aggregates the measured BCSI and the aggregated BSCI is analyzed to detect at least one activity of a plurality of activities.

A radar apparatus includes a plurality of transmit antennas that transmits a plurality of transmission signals using a multiplexing transmission, and a transmission circuit that applies phase rotation amounts corresponding to combinations of Doppler shift amounts and code sequences to the plurality of transmission signals. Each of the plurality of transmission signals is assigned a different combination among the combinations. The combinations include at least one combination of different numbers of multiplexing by the code sequences.

A radar apparatus includes a plurality of transmit antennas that transmits a plurality of transmission signals using a multiplexing transmission, and a transmission circuit that applies phase rotation amounts corresponding to combinations of Doppler shift amounts and code sequences to the plurality of transmission signals. Each of the plurality of transmission signals is assigned a different combination among the combinations. The combinations include at least one combination of different numbers of multiplexing by the code sequences.

According to an example aspect of the present invention, there is provided monitoring living facilities by a multichannel radar. A field of view within a frequency range from 1 to 1000 GHz, for example between 1 to 30 GHz, 10 to 30 GHz, 30 to 300 GHz or 300 to 1000 GHz, is scanned using a plurality of radar channels of the radar. Image units comprising at least amplitude and phase information are generated for a radar image on the basis of results of the scanning. Information indicating at least one error source of a physical movement of the radar and interrelated movements of targets within the field of view are determined on the basis of the image units. Results of the scanning are compensated on the basis of the determined error source. A radar image is generated on the basis of the compensated results.

According to an example aspect of the present invention, there is provided monitoring living facilities by a multichannel radar. A field of view within a frequency range from 1 to 1000 GHz, for example between 1 to 30 GHz, 10 to 30 GHz, 30 to 300 GHz or 300 to 1000 GHz, is scanned using a plurality of radar channels of the radar. Image units comprising at least amplitude and phase information are generated for a radar image on the basis of results of the scanning. Information indicating at least one error source of a physical movement of the radar and interrelated movements of targets within the field of view are determined on the basis of the image units. Results of the scanning are compensated on the basis of the determined error source. A radar image is generated on the basis of the compensated results.