# US 11,906,651 B2 · Radar-based detection using sparse array processing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,651 B2 - Document ID: US11906651B2 - Status: Granted - Kind: B2 - Application number: 17/185,040 - Filed: 2021-02-25 - Published: 2022-08-25 - Granted: 2024-02-20 - Earliest claimed: 2021-02-25 - Assignees: NXP B.V. - Applicants: NXP B.V. - Inventors: Ryan Haoyun Wu; Jun Li; Maik Brett; Michael Andreas Staudenmaier - Web page: https://patentgrep.com/patent/US11906651B2 ## CPC - G01S 7/2813: {Means providing a modification of the radiation pattern for cancelling noise, clutter or interfering signals, e.g. side lobe suppression, side lobe blanking, null-steering arrays (specially adapted to secondary radar systems G01S13/762; aerials or aerials systems H01Q21/29, H01Q25/00)} - G01S 7/354: {Extracting wanted echo-signals (Doppler systems G01S13/50)} - G01S 7/023: {Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques (auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36)} - G01S 7/2883: {using FFT processing} - G01S 7/52047: {for elimination of side lobes or of grating lobes; for increasing resolving power} - G01S 13/34: using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal - G01S 13/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S13/46) - G01S 13/584: {adapted for simultaneous range and velocity measurements} - G01S 7/0236: {Avoidance by space multiplex} - G01S 7/356: {involving particularities of FFT processing} - G01S 13/931: of land vehicles - G01S 2013/0254: {Active array antenna} - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract Exemplary aspects are directed to a radar-based detection circuit or system with signal reception circuitry to receive reflection signals in response to radar signals transmitted towards objects. The system may include logic/computer circuitry and a multi-input multi-output (MIMO) virtual array to enhance resolution or remove ambiguities otherwise present in processed reflection signals. The MIMO array may include sparse linear arrays, each being associated with a unique antenna-element spacing from among a set of unique co-prime antenna-element spacings. ## Claims ### Claim 1 An apparatus comprising: a radar circuit with signal transmission circuitry to transmit radar signals and with signal reception circuitry to receive, in response, reflection signals as reflections from objects; and computer processing circuitry to process data corresponding to the reflection signals in a multi-input multi-output (MIMO) virtual array characterized by having at least three embedded uniform sparse linear arrays, each of the at least three embedded uniform sparse linear arrays being associated with a unique antenna-element spacing from among a set of unique co-prime antenna-element spacings, wherein spacing values of the at least three embedded sparse linear arrays are co-prime, pairwise, and the at least three embedded sparse linear arrays form an array of sparse aperture of a size corresponding to a lowest common multiple of the spacing values. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the computer processing circuitry is to process the reflection signals using the MIMO virtual array, and wherein the set of unique co-prime antenna-element spacings is to cause respective unique grating lobe centers along a spatially discrete sampling spectrum. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the computer processing circuitry is to process the reflection signals based on each of the at least three embedded sparse linear arrays having a different detectable amplitude due to associated grating lobe centers not coinciding and mitigating ambiguity among side lobes adjacent to the grating lobe centers. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the set of unique co-prime antenna-element spacings is to cause respective unique grating lobe centers along a spatially discrete sampling spectrum, and wherein the grating lobe center of one of the at least three embedded sparse linear arrays is coincident with a null of the grating lobe center of another of the at least three embedded sparse linear arrays. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the at least three embedded sparse linear arrays include a first embedded sparse linear array, a second embedded sparse linear array, and a third embedded sparse linear array, with the second embedded sparse linear array and the third embedded sparse linear array further contributing to mitigation of ambiguity in detection of unique grating lobe centers along a spatially discrete sampling spectrum. ### Claim 6 (depends on 4) The apparatus of claim 4, wherein the at least three embedded sparse linear arrays include at least a first embedded sparse linear array, a second embedded sparse linear array, and a third embedded sparse linear array, respectively characterized by unique antenna element spacing values. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the computer processing circuitry to process the reflection signals using the MIMO virtual array as a composite array of the at least three embedded sparse linear arrays, and the composite array is characterized in that power from the at least three embedded sparse linear arrays do not coherently add up in the composite array. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the radar circuit includes physical transmitting and receiving antenna elements in sparse spacing arrangements defined as a function of the MIMO virtual array as a composite array of the at least three embedded sparse linear arrays. ### Claim 9 (depends on 1) The apparatus of claim 1, further including computer processing circuitry to process the reflection signals using the MIMO virtual array to ascertain positional characteristics of at least one of the objects based on resolution estimates defined by a combination of position vectors corresponding to the MIMO virtual array represented by the at least three embedded sparse linear arrays and based on angle-of-arrival estimates associated with chirps processed by the radar circuitry. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the at least three embedded sparse linear arrays are arranged to represent the MIMO virtual array as a composite sparse pattern array having an effective spacing pattern which extends or repeats. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein the at least three embedded sparse linear arrays include between three and six embedded sparse linear arrays, and wherein the computer processing circuitry is to process angle of arrival (AoA) information by performing computations based on each of said at least three embedded uniform sparse linear arrays, and then determining further or final AoA data based on the AoA information which is found to be consistent across outputs respectively provided by said at least three embedded uniform sparse linear arrays. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein the at least three embedded sparse linear arrays are arranged to represent the MIMO virtual array as a composite sparse pattern array having an effective spacing pattern which repeats. ### Claim 13 For use in a radar circuit with signal transmission circuitry, a method comprising: transmitting radar signals and, in response, receiving reflection signals as reflections from objects; and providing a multi-input multi-output (MIMO) virtual array, via computer processing circuitry, characterized by having at least three embedded sparse linear arrays, each of the at least three embedded sparse linear arrays being uniform and each being associated with a unique antenna-element spacing from among a set of unique co-prime antenna-element spacings, wherein spacing values of the at least three embedded sparse linear arrays are co-prime, pairwise, and the at least three embedded sparse linear arrays form an array of sparse aperture of a size corresponding to a lowest common multiple of the spacing values. ### Claim 14 (depends on 13) The method of claim 13, wherein the set of unique co-prime antenna-element spacings are used to cause respective unique grating lobe centers along a spatially discrete sampling spectrum. ### Claim 15 (depends on 13) The method of claim 13, wherein the at least three embedded sparse linear arrays are arranged to represent the MIMO virtual array as a composite sparse pattern array having an effective spacing pattern which extends or repeats. ### Claim 16 (depends on 13) The method of claim 13, wherein the at least three embedded sparse linear arrays include between three and six embedded sparse linear arrays. ### Claim 17 (depends on 13) The method of claim 13, wherein the at least three embedded sparse linear arrays are arranged to represent the MIMO virtual array as a composite sparse pattern array having an effective spacing pattern which repeats.