Embodiments of systems and methods for estimating direction of arrival are disclosed. A device includes a signal processing unit that includes processing circuitry and memory coupled to the processing circuitry, where the processing circuitry includes multiple vector processing units, each vector processing unit configured to receive an antenna input vector, receive an angular spectrum vector, retrieve a first and second weighting vectors from the memory, generate a processed antenna input vector by performing a circular convolution of the antenna input vector with the first weighting vector, generate a processed angular spectrum vector by performing a circular convolution of the angular spectrum vector with the second weighting vector, and generate a refined angular spectrum vector, which indicates angular position of one or more radar targets, by applying a non-linear activation function to a sum of the processed antenna input vector and the processed angular spectrum vector.

A method, performed by a network node, may be provided. The method comprises transmitting, to a wireless device, control signalling indicating to the wireless device that, upon receiving a downlink signal from the network node, the wireless device is to respond by transmitting an uplink signal. The downlink signal may comprise a first downlink polarisation and a second downlink polarisation. The uplink signal may comprise a first uplink polarisation and a second uplink polarisation. The downlink signal may have a measured downlink characteristic. The measured downlink characteristic may comprise a downlink amplitude ratio between the amplitude of the downlink signal in the first downlink polarisation and the amplitude of the downlink signal in the second downlink polarisation.

Techniques are provided for steering vector generation. A methodology implementing the techniques according to an embodiment includes converting time domain data received from an antenna array to channelized frequency domain data. The method also includes receiving a request from a signal detection system, the request including a timestamp and duration of a detected signal of interest (SOI) and an indication that the SOI is pulsed or continuous. The method further includes generating, for a pulsed SOI, steering vectors to steer the antenna array to the pulsed SOI based on a segment of the time domain data stored in a first memory and identified by the time stamp and duration; and generating, for a continuous SOI, steering vectors to steer the antenna array to the continuous SOI based on a segment of the channelized frequency domain data stored in a second memory and identified by the time stamp and duration.

An apparatus for estimating an angle of arrival, comprises: a window setting unit for setting a window time that is a time interval for comparing a template signal and each of a plurality of reception signals obtained by receiving a transmission signal transmitted a pre-designated number of times; a template generator that generates a template signal of a waveform corresponding to the transmission signal, by adjusting a generation time point in units of the window time; a plurality of signal correlators provided corresponding to each of the plurality of antennas, and detecting a level of a correlation signal obtained by correlating a corresponding reception signal; and an angle of arrival determination unit, determining a reception time at which each of the plurality of reception signals is received by a corresponding antenna, and estimating the angle of arrival of the transmission signal using a difference between the determined reception times.

Methods and systems for spatial filtering transmitters and receivers capable of simultaneous communication with one or more receivers and transmitters, respectively, the receivers capable of outputting source directions to humans or devices. The methods and systems use spherical wave field partial wave expansion (PWE) models for transmitted and received fields at antennas and for waves generated by contributing sources. The source PWE models have expansion coefficients expressed as functions of directional coordinates of the sources. For spatial filtering receivers a processor uses the output signals from at least one sensor outputting signals consistent with Nyquist criteria representative of the wave field and the source PWE model to determines directional coordinates of sources (wherein the number of floating point operations are reduced) and outputs the directional coordinates and communications to a reporter configured for reporting information to humans. For spatial filtering transmitters a processor uses known receiver directions and source partial wave expansions to generate signals for transducers producing a composite total wave field conveying communications to the specified receivers. The methods and communications reduce the processing required for transmitting and receiving spatially filtered communications.

Methods and systems for spatial filtering transmitters and receivers capable of simultaneous communication with one or more receivers and transmitters, respectively, the receivers capable of outputting source directions to humans or devices. The methods and systems use spherical wave field partial wave expansion (PWE) models for transmitted and received fields at antennas and for waves generated by contributing sources. The source PWE models have expansion coefficients expressed as functions of directional coordinates of the sources. For spatial filtering receivers a processor uses the output signals from at least one sensor outputting signals consistent with Nyquist criteria representative of the wave field and the source PWE model to determines directional coordinates of sources (wherein the number of floating point operations are reduced) and outputs the directional coordinates and communications to a reporter configured for reporting information to humans. For spatial filtering transmitters a processor uses known receiver directions and source partial wave expansions to generate signals for transducers producing a composite total wave field conveying communications to the specified receivers. The methods and communications reduce the processing required for transmitting and receiving spatially filtered communications.

A wave source location direction estimation apparatus includes: a signal acquisition unit to acquire a reception signal of one or more radio waves from an antenna to receive the one or more radio waves from among a direct wave which is a radio wave from a wave source and one or more multipath waves which are radio waves from the wave source; and a profile calculation unit to calculate an angle profile including directions of incidence of the respective radio waves on the antenna, and reception power levels of the respective radio waves on the basis of the reception signal acquired by the signal acquisition unit. In addition, the wave source location direction estimation apparatus includes a direction estimation unit to estimate a direction in which the wave source is located on the basis of the angle profile calculated by the profile calculation unit.

A wave source location direction estimation apparatus includes: a signal acquisition unit to acquire a reception signal of one or more radio waves from an antenna to receive the one or more radio waves from among a direct wave which is a radio wave from a wave source and one or more multipath waves which are radio waves from the wave source; and a profile calculation unit to calculate an angle profile including directions of incidence of the respective radio waves on the antenna, and reception power levels of the respective radio waves on the basis of the reception signal acquired by the signal acquisition unit. In addition, the wave source location direction estimation apparatus includes a direction estimation unit to estimate a direction in which the wave source is located on the basis of the angle profile calculated by the profile calculation unit.

Disclosed in the present invention is a two-dimensional direction-of-arrival estimation method for a coprime surface array based on virtual domain tensor filling, which mainly solves the problems of the loss of multi-dimensional signal structural information and the inability to fully utilize virtual domain statistics in the existing method. The steps thereof are as follows: constructing a coprime surface array; modeling a tensor of a received signal of the coprime surface array; constructing an augmented non-continuous virtual surface array based on cross-correlation tensor transformation of the coprime surface array; deriving a virtual domain tensor based on mirror extension of the non-continuous virtual surface array; dispersing contiguous missing elements by reconstructing the virtual domain tensor; filling the virtual domain tensor based on the minimization of a tensor kernel norm; and decomposing a filled virtual domain tensor to obtain a direction-of-arrival estimation result.

An example method includes: A first communication apparatus and a second communication apparatus determine N target frequencies. The first communication apparatus sends a sensing signal to the second communication apparatus on the N target frequencies. The second communication apparatus performs angle measurement based on the sensing signal. The N target frequencies belong to a candidate frequency set that includes M candidate frequencies, 1<N<M, and a least common multiple of processed angle measurement ranges corresponding to the N target frequencies is greater than a preset angle measurement range, or the least common multiple of the processed angle measurement ranges corresponding to the N target frequencies is greater than or equal to a least common multiple of processed angle measurement ranges corresponding to any N candidate frequencies in the candidate frequency set.