RADAR DEVICE AND METHOD FOR DETECTING RADAR TARGETS

Abstract

A radar device (400) comprising: a first radar IC (410-1) for processing first received signals from first antennas of an antenna array (414), wherein the first radar IC is configured to determine a first combined range / Doppler map by combining range / Doppler maps of each of the first antennas of the antenna array; determine first selected range / Doppler cells of the first combined range / Doppler map that meet a predetermined selection criterion; determine first confirmed range / Doppler cells of the first combined range / Doppler map that meet a predetermined confirmation criterion;at least one second radar IC (410-2) for processing second received signals from second antennas of the antenna array (414), wherein the second radar IC is configured to determine a second combined range / Doppler map by combining range / Doppler maps of each of the second antennas of the antenna array, to determine two selected range / Doppler cells of the second combined range / Doppler map that meet the predetermined selection criterion, and to determine two range / Doppler cells of the second combined range / Doppler map to be confirmed that meet the predetermined confirmation criterion. The first radar IC is configured to communicate information indicating the first range / Doppler cells to be confirmed to the second radar IC (410-2).wherein the second radar IC is configured to determine a set of range / Doppler cells to be confirmed by logically combining the first and second range / Doppler cells to be confirmed, communicating the set of range / Doppler cells to be confirmed to the first radar IC (410-1), wherein the first radar IC is configured to communicate values ​​of the first combined range / Doppler map corresponding to the set of range / Doppler cells to be confirmed to the second radar IC, wherein the second radar IC is configured to perform a summation of values ​​of the first and second combined range / Doppler maps corresponding to the set of range / Doppler cells to be confirmed in order to obtain summed values ​​of the set of range / Doppler cells to be confirmed;Selecting summed values ​​of the set of distance / Doppler cells to be confirmed that exceed a predefined threshold as the third selected distance / Doppler cells and combining the third selected distance / Doppler cells with the first selected distance / Doppler cells and the second selected distance / Doppler cells to obtain collectively selected distance / Doppler cells; a data interface (420) configured to forward information indicating the collectively selected distance / Doppler cells to a common processor (410-1; 410-2; 410-3) for further processing.

Description

Area

[0001] The present disclosure relates to radar systems and more precisely to radar concepts that use signal processing techniques distributed among a plurality of integrated radar circuits. background

[0002] Automotive radars, along with other environmental sensors such as lidar, ultrasound, and cameras, form one of the backbones of self-driving cars and advanced driver assistance systems (ADAS). These technological advancements are made possible by complex systems with signal processing paths from radars / sensors to one or more controllers. Automotive radar systems enable the detection of objects and obstacles, as well as their position and speed relative to a vehicle. The development of signal processing techniques, along with advancements in millimeter-wave (mm-wave) semiconductor technology, plays a crucial role in automotive radar systems.Various signal processing techniques were developed to provide better resolution and estimation performance across all measurement dimensions: distance, azimuth / elevation angle, and speed of the targets surrounding the vehicles.

[0003] In frequency-modulated continuous-wave (FMCW) radar systems, for example, it is known that they obtain range, velocity, and angle information by performing several Fast Fourier Transforms (FFTs) on samples of radar mixer outputs. A first FFT, also commonly referred to as a range FFT, yields range information. A second FFT on the range-transformed samples, also commonly referred to as a Doppler FFT, yields velocity information. The first and second FFTs together form a so-called 2D range / Doppler map, comprising range and velocity (FFT) bins, also known as range / Doppler cells. A third FFT, comprising phase information from signals from different antenna elements of an antenna array, can provide additional spatial or angular information.

[0004] As automated driving becomes increasingly prevalent, so too do the demands on angular resolution, azimuth, and elevation. This means that the number of receive channels in a radar system is constantly increasing. On the other hand, the number of RF pins on a radar monolithic microwave integrated circuit (MMIC) is limited by power dissipation and the number of pins. Therefore, automotive radars can increasingly combine or cascade multiple MMIC devices to handle a growing number of receive channels.

[0005] Therefore, there is a need for improved signal processing concepts when multiple cascaded MMIC devices are used in a radar system. Summary

[0006] This need is met by radar devices and methods according to the independent claims. Some advantageous embodiments are addressed by the dependent claims.

[0007] According to a first aspect, the present disclosure proposes a radar device. The radar device comprises a first radar IC configured to process first received signals from first antennas of an antenna array. The first radar IC is configured to determine a first combined range / Doppler map by combining range / Doppler maps from each of the first antennas of the antenna array. The first radar IC is further configured to determine first selected range / Doppler cells of the first combined range / Doppler map that meet a predetermined selection criterion. The first radar IC is further configured to determine first verifiable range / Doppler cells of the first combined range / Doppler map that meet a predetermined verification criterion.Confirmable range / Doppler cells refer here to range / Doppler cells for which it is still necessary to confirm whether they are suitable for further processing (e.g., target detection). The radar device further comprises at least one second radar IC configured to process second received signals from second antennas of the antenna array. The second radar IC is configured to determine a second combined range / Doppler map by combining range / Doppler maps from each of the second antennas of the antenna array. The second radar IC is further configured to determine two selected range / Doppler cells of the second combined range / Doppler map that meet the predetermined selection criterion.The second radar IC is further equipped to determine two verifiable range / Doppler cells of the second combined range / Doppler map that meet the predetermined verification criterion.

[0008] The first radar IC is configured to communicate information displaying the first confirmatory range / Doppler cells to the second radar IC. The second radar IC is configured to determine a combined set of confirmatory range / Doppler cells by logically combining the first confirmatory range / Doppler cells of the first radar IC with the second confirmatory range / Doppler cells of the second radar IC. The second radar IC is further configured to communicate this combined set of confirmatory range / Doppler cells to the first radar IC. Responding to this, the first radar IC is configured to communicate values ​​from the first combined range / Doppler map corresponding to the combined set of confirmatory range / Doppler cells to the second radar IC.The second radar IC is then configured to perform a summation of values ​​from the first and second combined range / Doppler maps corresponding to the combined set of confirmatory range / Doppler cells, in order to obtain summed values ​​of the combined set of confirmatory range / Doppler cells. The second radar IC is further configured to select summed values ​​from the combined set of confirmatory range / Doppler cells that exceed a predefined threshold as the third selected range / Doppler cells, and to logically combine the third selected range / Doppler cells with the first selected range / Doppler cells and the second selected range / Doppler cells to obtain collectively selected range / Doppler cells for further processing (e.g., target detection).

[0009] The radar device further comprises a data interface configured to transmit information displayed by the collectively selected range / Doppler cells to a common processor for further processing, such as target detection based on the collectively selected range / Doppler cells. In some embodiments, the data interface couples the first radar IC to the second radar IC. Additionally or alternatively, the data interface couples the first radar IC and / or the second radar IC to an external processor.

[0010] For example, a radar IC can be a standalone processor or an MMIC with integrated processing. In some embodiments, the antenna array can be a linear receive-antenna array in one dimension, such as azimuth or elevation. Thus, the first antennas can be considered a first subgroup, and the second antennas can be considered a second subgroup of the same linear receive-antenna array.

[0011] Thus, the present disclosure proposes distributed signal processing of first and second received signals from an ordinary antenna array. The first received signals are processed by the first radar IC, while the second signals are processed by the second radar IC to obtain respective range / Doppler maps. While the first and second radar ICs independently compute their respective 2D range / Doppler maps and the range / Doppler cells of (potential) interest, the spatial or angular information inherent in the received signals of the antenna array cannot be estimated independently, as information indicating the phases of both the first and second received signals (phase progression across the first and second antennas of the antenna array) is required.Instead of exchanging raw received data via the data interface, the present disclosure proposes independently calculating respective 2D range / Doppler maps in the first and second radar ICs, detecting the first and second selected range / Doppler cells and the first and second confirmable range / Doppler cells based on contiguous or non-contiguous integration of the respective range / Doppler maps, and then exchanging the information indicating the selected and confirmable range / Doppler cells to evaluate whether the confirmable range / Doppler cells should be confirmed for further processing. In this way, the amount of data shared via the data interface, as well as the latency for data exchange, can be significantly reduced.The person skilled in the art who benefits from the present disclosure will recognize that the proposed distributed signal processing concept is not limited to two radar ICs, but can be extended to any number.

[0012] In some embodiments, the first radar IC is configured to determine the first combined range / Doppler map by combining range / Doppler maps from each of the first antennas of the antenna array, and the second radar IC is configured to determine the second combined range / Doppler map by combining range / Doppler maps from each of the second antennas of the antenna array. That is, the first radar IC can be configured to determine an antenna-specific range / Doppler map for each of the first received signals. Each of the first received signals originates from a different antenna of the first array. The first radar IC can be configured to determine the first range / Doppler map based on a summation or integration of the antenna-specific range / Doppler maps of the first received signals.The second radar IC can be configured to determine an antenna-specific range / Doppler map for each of the second received signals. Each of the second received signals originates from a different antenna. The second radar IC can be configured to determine the second range / Doppler map based on a summation or integration of the antenna-specific range / Doppler maps of the second received signals.

[0013] In some embodiments, the predetermined selection criterion used to determine the first / second selected distance / Doppler cells may include amplitude or energy levels associated with the indices or FFT bins of the first / second combined distance / Doppler maps above a predefined first threshold, which may be adaptive. Thus, the first and second selected distance / Doppler cells may include FFT bins (or indices thereof) of the first / second combined distance / Doppler map that meet the predetermined selection criterion.The predetermined confirmation criterion, based on which the first / second confirmable distance / Doppler cells are determined, may include amplitude or energy levels that are assigned to the indices or FFT bins of the first / second combined distance / Doppler maps below the first threshold but above a (lower) second threshold.

[0014] In alternative embodiments, the predetermined confirmation criterion can include a distance level above a first threshold, and the predetermined selection criterion can include a distance level below the first threshold and above a second threshold.

[0015] In some embodiments, the first radar IC is configured to communicate binary information, indicating the first selected range / Doppler cells (FFT bins) and the first confirmable range / Doppler cells, to the second radar IC. This minimizes the amount of information exchanged between the radar ICs.

[0016] In some embodiments, the second radar IC is configured to combine the first and second selected range / Doppler cells via a logical OR to obtain a combined set of selected range / Doppler cells, and to combine the combined set of selected range / Doppler cells with the third selected range / Doppler cells via a logical OR to obtain the collectively selected range / Doppler cells as final detections. The collectively selected range / Doppler cells or final detections can then be forwarded to a remote processing unit, such as a vehicle's electronic control unit (ECU).Additionally, phase information associated with the collectively selected range / Doppler cells or final detections can be forwarded to the remote processor unit to determine the spatial directions of the final detections, for example, by using an FFT on the final detections via the antenna array. The phase information associated with the final detections can be collected by all radar ICs via the common processor, for example, the second radar IC, and forwarded to the remote processor unit. Here, the common processor acts as the communication master. Alternatively, the phase information associated with the final detections can be communicated to the remote processor unit by the radar ICs in a distributed manner.

[0017] In some embodiments, the shared processor (for example, the second radar IC) could also be configured to determine the spatial orientations of target objects based on the final detections and the phase information assigned to them. The final detections and their associated spatial orientations could then be forwarded to the remote processor unit for further processing or display.

[0018] In some embodiments, the first radar IC can be configured to forward information (for example, binary information) indicating its selected and confirmable range / Doppler cells to the second radar IC via the data interface. The second radar IC can be configured to logically combine the first and second selected range / Doppler cells to obtain a combined set of selected range / Doppler cells as final detections. This combination can be achieved, for example, by a logical OR operation on the first and second selected range / Doppler cells or on their binary information.The second radar IC can further be configured to determine the combined set of verifiable range / Doppler cells by performing a logical OR operation on the first verifiable range / Doppler cells of the first radar IC with the second verifiable range / Doppler cells of the second radar IC, and to communicate this set of verifiable range / Doppler cells to the first radar IC. Responding to this, the first radar IC is configured to communicate (complex) FFT bin values ​​of the first combined range / Doppler map, corresponding to the combined set of verifiable range / Doppler cells, to the second radar IC.The second radar IC is then configured to perform a coherent or non-coherent integration of FFT bin values ​​of the first and second combined range / Doppler maps corresponding to the combined set of confirmatory range / Doppler cells, in order to obtain integrated values ​​of the combined set of confirmatory range / Doppler cells. The second radar IC is further configured to select integrated values ​​of the combined set of confirmatory range / Doppler cells that exceed a predefined threshold (e.g., the predetermined selection criterion) as further final detections and to logically combine these further final detections with the final detections based on the logically combined first and second selected range / Doppler cells.Additionally, the first radar IC can be configured to forward phase (progression) information associated with the final detections to the second radar IC via the data interface. With this additional phase (progression) information, the second radar IC, or another remote processing unit, can determine the spatial orientation of target objects based on the final detections and the associated phase (progression) information.

[0019] In some embodiments, a remote processing unit, such as an external ECU, can act as the common processor. Here, the first radar IC can be configured to transmit information (for example, binary information) indicating its detected first subregion directly or indirectly to the ECU via the data interface. The second radar IC can be configured to transmit information (for example, binary information) indicating its selected and confirmable range / Doppler cells directly or indirectly to the ECU via the data interface. "Direct" here can refer to a direct interface between the first / second radar IC and the ECU. "Indirect" can refer to communication via an intermediate communication master.The external ECU can be configured to combine the first and second selected range / Doppler cells to obtain a combined set of selected range / Doppler cells as final detections. This combination can be achieved, for example, through a logical OR operation of the first and second selected range / Doppler cells or their binary information. The external ECU can further be configured to determine the combined set of confirmatory range / Doppler cells by logically ORing the first confirmatory range / Doppler cells of the first radar IC with the second confirmatory range / Doppler cells of the second radar IC, and to communicate the combined set of confirmatory range / Doppler cells to the first radar IC.In response, the respective radar ICs can be configured to communicate (complex) FFT bin values ​​of the respective combined range / Doppler map, corresponding to the combined set of verifiable range / Doppler cells, to the external ECU. The external ECU is then configured to perform a coherent or non-coherent integration of FFT bin values ​​of the first and second combined range / Doppler maps, corresponding to the combined set of verifiable range / Doppler cells, to obtain integrated values ​​of the combined set of verifiable range / Doppler cells. The external ECU is further configured to output integrated values ​​of the combined set of verifiable range / Doppler cells that exceed a predefined threshold (e.g.,(exceeding the predetermined selection criterion) to select further final detections and logically combine these further final detections with the final detections based on the logically combined first and second selected range / Doppler cells. Additionally, the respective radar ICs can be configured to transmit phase (progression) information associated with the final detections to the external ECU via the data interface. With this additional phase (progression) information, the external ECU can determine the spatial orientation of target objects based on the final detections and the phase (progression) information associated with them.

[0020] In some embodiments, the radar device can be configured to synchronize the signal processing of the first and second radar ICs using a common synchronization signal. This common synchronization signal can be based on a timing master device, which can be, for example, either the first or the second radar IC. In some embodiments, the data interface can be configured to forward the first and / or the second selected and verifiable range / Doppler cells as data, compressed by a suitable data compression scheme.

[0021] According to another aspect, the present disclosure proposes a method for detecting radar targets. The method comprises - Receiving a plurality of first received signals from first antennas of an antenna array with a first radar IC; - Determining a first combined range / Doppler map by combining range / Doppler maps of each of the first antennas of the antenna array in the first radar IC; - Determining the first selected range / Doppler cells of the first combined range / Doppler map that meet a predetermined confirmation criterion in the first radar IC; - Determining the first verifiable range / Doppler cells of the first combined range / Doppler map that meet a predetermined verification criterion in the first radar IC; - Receiving multiple second received signals from second antennas of the antenna array with a second radar IC; - Determining a second combined range / Doppler map by combining range / Doppler maps of each of the second antennas of the antenna array in the second radar IC; - Determining the second selected range / Doppler cells of the second combined range / Doppler map that meet the predetermined selection criterion in the second radar IC; - Determining the second verifiable range / Doppler cells of the second combined range / Doppler map that meet the predetermined verification criterion in the second radar IC; - Communicating information indicating the first confirmatory range / Doppler cells from the first to the second radar IC or other common processor; - Determining a combined set of confirmatory range / Doppler cells by logically combining the first and second confirmatory range / Doppler cells in the second radar IC; - Communicating the combined set of confirmatory range / Doppler cells to the first radar IC; - Communicating values ​​of the first combined range / Doppler map corresponding to the combined set of confirmatory range / Doppler cells from the first radar IC to the second radar IC or the common processor; - Performing a summation of values ​​from the first and second combined range / Doppler maps corresponding to the combined set of confirmatory range / Doppler cells to obtain summed values ​​of the combined set of confirmatory range / Doppler cells in the second radar IC or the common processor; - Selecting summed values ​​of the combined set of confirmatory distance / Doppler cells that exceed a predefined threshold as the third selected distance / Doppler cells and combining the third selected distance / Doppler cells with the first and second selected distance / Doppler cells to obtain collectively selected distance / Doppler cells; - Forwarding information displayed by the collectively selected distance / Doppler cells for further processing (e.g., target detection).

[0022] In some embodiments, the method may further include the detection of target objects based on the collectively selected distance / Doppler cells.

[0023] In some embodiments, the method may further include determining spatial directions of target objects based on the collectively selected distance / Doppler cells and based on phases of the first and second received signals assigned to the collectively selected distance / Doppler cells.

[0024] According to another aspect, the present disclosure proposes a method for detecting radar targets. The method comprises - Receiving a plurality of initial received signals from the first antennas of an antenna array; - Determining a first combined range / Doppler map by combining range / Doppler maps of each of the first antennas; - Determining the first confirmable distance / Doppler cells of the first combined distance / Doppler map that meet a predetermined confirmation criterion; - Receiving multiple second received signals from second antennas of the antenna array; - Determining a second combined range / Doppler map by combining range / Doppler maps from each of the second antennas; - Determining the second confirmatory distance / Doppler cells of the second combined distance / Doppler map that meet the predetermined confirmation criterion; - Combining the first and second confirmatory distance / Doppler cells to obtain a combined set of confirmatory distance / Doppler cells; - Summing values ​​of the first and second combined distance / Doppler maps corresponding to the combined set of confirmatory distance / Doppler cells to obtain summed values ​​of the combined confirmatory distance / Doppler cells; and - Selecting summed values ​​of the combined set of confirmatory distance / Doppler cells that exceed a predefined selection threshold as selected distance / Doppler cells.

[0025] In some embodiments, the method may also include the detection of target objects based on the selected distance / Doppler cells.

[0026] In some embodiments, the predetermined selection threshold may include a distance / Doppler cell amplitude or energy level threshold, and the predetermined confirmation criterion may include a distance / Doppler cell amplitude or energy level below the predetermined selection threshold and above a lower threshold.

[0027] In some embodiments, the predetermined confirmation criterion may include a distance level above a first threshold, and the predetermined selection threshold may include a distance level below the first threshold and above a second threshold.

[0028] In some embodiments, the method may further include determining spatial directions of target objects based on the selected distance / Doppler cells and based on phases of the first and second received signals assigned to the selected distance / Doppler cells.

[0029] According to yet another aspect, the present disclosure proposes a method for detecting radar targets. The device comprises a first radar IC that is trained to - Receiving a plurality of initial received signals from the first antennas of an antenna array; - Determining a first combined range / Doppler map by combining range / Doppler maps of each of the first antennas; - Determining the first confirmable distance / Doppler cells of the first combined distance / Doppler map that meet a predetermined confirmation criterion; a second radar IC that is trained to - Receiving multiple second received signals from second antennas of the antenna array; - Determining a second combined range / Doppler map by combining range / Doppler maps from each of the second antennas; - Determining the second confirmatory distance / Doppler cells of the second combined distance / Doppler map that meet the predetermined confirmation criterion; a processing circuit arrangement configured to - Combining the first and second confirmatory distance / Doppler cells to obtain a combined set of confirmatory distance / Doppler cells; - Summing values ​​of the first and second combined distance / Doppler maps corresponding to the combined set of confirmatory distance / Doppler cells to obtain summed values ​​of the combined confirmatory distance / Doppler cells; and - Selecting summed values ​​of the combined set of confirmatory distance / Doppler cells that exceed a predefined selection threshold as selected distance / Doppler cells.

[0030] Exemplary embodiments of the present disclosure can be used to reduce latency, since it is not necessary to exchange raw data via the data interface. Instead, only basic information about the selected distance / Doppler map subregions can be exchanged. List of characters

[0031] The following are some examples of devices and / or methods, described solely by way of example and with reference to the accompanying figures, in which Fig. Figure 1 shows a block diagram of a conventional radar signal processing chain; Fig. 2 shows a 2D joint range Doppler estimation using an FMCW radar; Fig. 3 represents an azimuth angle estimation using a uniform linear antenna array; Fig. 4 shows a schematic block diagram of a radar device according to exemplary embodiments of the present disclosure; Fig. 5 shows an example of exchanged data; Fig. 6a shows an exemplary signal flow according to an exemplary implementation; Fig. 6b shows an exemplary signal flow according to another exemplary implementation; Fig. 7a shows a flowchart of distributed radar signal processing according to an embodiment; Fig. 7b shows a flowchart of distributed radar signal processing according to another embodiment; Fig. 7c shows a flowchart of distributed radar signal processing according to a further embodiment; Fig. 7d shows a flowchart of distributed radar signal processing according to a further embodiment; Fig. 7a shows a flowchart of distributed radar signal processing according to an embodiment; Fig. 8a shows a block diagram of a distributed radar signal processing system according to an exemplary embodiment; and Fig. Figure 8b shows a block diagram of a distributed radar signal processing system according to another embodiment. Detailed description

[0032] Several examples will now be described in more detail with reference to the accompanying drawings, which illustrate some of these examples. For the sake of clarity, the thickness of lines, layers, and / or regions in the figures may be exaggerated.

[0033] While further examples of various modifications and alternative forms are suitable, some specific examples are accordingly shown in the figures and are described in detail below. However, this detailed description does not limit further examples to the specific forms described. Further examples may encompass all modifications, correspondences, and alternatives that fall within the scope of the disclosure. Equal or similar references throughout the description of the figures refer to identical or similar elements that, upon comparison, may be implemented identically or in a modified form while providing the same or a similar function.

[0034] It is understood that when an element is described as "connected" or "coupled" to another element, the elements may be connected or coupled directly or via one or more intermediate elements. When two elements A and B are combined using "or," this is to be understood as revealing all possible combinations, i.e., only A, only B, and A and B, unless explicitly or implicitly stated otherwise. An alternative formulation for the same combinations is "at least one of A and B" or "A and / or B." The same applies analogously to combinations of more than two elements.

[0035] The terminology used herein to describe certain examples is not intended to be limiting for further examples. Where a singular form, such as "a" and "the," is used, and the use of only a single element is neither explicitly nor implicitly defined as mandatory, further examples may also use plural elements to implement the same function. Similarly, where functionality is subsequently described as being implemented using multiple elements, further examples may implement the same functionality using a single element or a single processing entity.It is further understood that the terms “include”, “comprehensive”, “exhibit” and / or “exhibit” when used specify the presence of the indicated features, integers, steps, operations, processes, actions, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, processes, actions, elements, components and / or any group thereof.

[0036] Unless otherwise defined, all terms (including technical and scientific terms) are used here in their usual meaning within the field to which the examples belong.

[0037] Fig. Figure 1 shows a block diagram of an example of a conventional radar signal processing chain 100.

[0038] A radio frequency (RF) transceiver front end 110 is used to generate transmit (TX) radar signals that can be emitted via one or more transmit antennas 112. The radar signals can be in frequency bands ranging from, for example, 3 MHz to 300 GHz. Automotive radar systems can typically operate in bands in the 24 GHz and 77 GHz sections of the electromagnetic spectrum, known as mm-wave frequencies, so that adequate velocity and range resolution can be achieved. One or more receive (Rx) antennas 114 can be used to receive electromagnetic waves (radar signals) reflected by targets. Radar operation includes range estimation, relative velocity estimation, and possibly directional estimation with respect to the targets. The latter can be performed when more than one receive antenna is used in a receive-antenna array.Radar systems that use both multiple transmit and multiple receive antennas are generally referred to as MIMO radars. For proper transmit antenna spacing, the multiple-input multiple-output (MIMO) radar can emulate a phased array radar with a larger aperture. This larger array can be referred to as a virtual array.

[0039] A range processor 120, connected downstream of the RF transceiver front end 110, is configured to perform range estimation. A distance R to a target can be determined based on the round-trip time delay used by electromagnetic waves to propagate to and from that target: R = (cτ / 2), where τ is the round-trip time delay in seconds and c is the speed of light in meters per second. Thus, estimating τ enables range measurement. A radar configuration using frequency-modulated (FM) CW pulses (sometimes referred to as FMCW chirps or ramps) can provide simultaneous range / speed estimation in multi-target traffic scenarios. An FMCW radar transmits periodic FM pulses (also referred to as chirps or ramps) whose frequency continuously increases (or decreases) during the pulse.The received signal reflected from a target is conjugated and mixed with the transmitted signal to create a low-frequency beat signal (also called a baseband signal) whose frequency indicates the distance to the target. This operation can be repeated for P consecutive FMCW pulses. Two-dimensional (2D) waveforms 210 in. Fig. The two represent successive reflected pulses arranged over two time indices, p and n. The so-called slow time index p simply corresponds to the number of pulses. On the other hand, the so-called fast time index n assumes that for each pulse, the corresponding continuous beat signal with frequency ƒ s The system is sampled to collect N samples within a pulse duration T.

[0040] The distance processor 120 can be configured to perform a first discrete Fourier transform (e.g., FFT) over the fast time n to determine the beat frequency ƒ b coupled to the Doppler frequency ƒd to obtain. This operation is also commonly known as distance transformation or distance gating, which allows the estimation of a Doppler shift corresponding to a single distance gate or bin by applying a second Fourier transform (e.g., FFT) over slow time. This can be performed by a velocity processing element 130. Thus, a distance / Doppler map 220 can be generated using a 2D FFT, see Fig. 2. The distance Doppler map 220 comprises a 2D grid of distance Doppler cells or bins, each distance Doppler cell corresponding to a specific distance and velocity. An example distance / Doppler map 220 is shown in Fig. Figure 2 shows two targets: the first at a distance of 10 m and a relative speed of 0 mph, and the second at a distance of 20 m and a relative speed of 20 mph. These targets may represent sub-regions of interest on the distance / Doppler map.

[0041] It was previously assumed that automotive radars only received reflections from targets of interest, such as vehicles ahead. However, in addition to direct reflections from a target of interest, the radar also receives reflections from road debris, guardrails, and walls, for example. This unwanted feedback to the radar is commonly called clutter. The number of clutters in the system changes as the environment surrounding the vehicle varies. Therefore, adaptive algorithms such as Constant False Alarm Rate (CFAR) processing can be used to mitigate the effect of clutter. To identify valid targets in the presence of clutter, a suitable target detection threshold should be selected. For example, if the amplitude or energy of a range / Doppler map at an estimated distance is greater than a certain threshold, the target can be considered detected.Thus, the threshold can depend on the noise (e.g., clutter) in the given system. As clutter increases, a higher threshold can be selected. One possible CFAR method, based on cell or bin averaging, can use a sliding window to derive the local clutter level by averaging multiple distance bins. This described threshold selection and target (peak) detection is performed in processing block 140.

[0042] The use of broadband pulses, such as FMCW pulses, provides target differentiation based on both distance and speed. Directional differentiation can be achieved using a multi-antenna array, as in multi-antenna radar systems. Multi-antenna radar systems can utilize multiple transmitters, multiple receivers, and multiple waveforms to exploit all available degrees of freedom. To spatially resolve targets and provide a comprehensive representation of the traffic scene, the angular location of targets is estimated. Thus, in automotive radars, the location of a target can be described with respect to a spherical coordinate system (R, θ, p), where (θ, p) denotes the azimuth and elevation angles, respectively.A single-antenna radar setup is sufficient to provide a range-velocity map but is insufficient to provide angular information, as the measured time delay lacks information regarding the angular positions of the targets. To enable direction estimation, the radar is designed to receive reflected waves using multiple antennas. For example, positioning a target using electromagnetic waves in two dimensions requires that the reflected wave data from the object be collected in two distinct dimensions. These distinct dimensions can be generated in many ways using combinations of time, frequency, and space via receiving antennas. For example, a linear receiving antenna array and broadband waveforms such as FMCW generate two distinct dimensions.Additionally, shorter wavelengths in millimeter-wave bands correspond to smaller aperture sizes, allowing many antenna elements to be packed densely into an antenna array. The resulting stronger and sharper effective radiation beam thus increases the resolution of angle measurements.

[0043] Consider an antenna array positioned in a plane z = 0, and let / be the abscissa corresponding to each receiving antenna position, see Fig. 3. (R q , θ q ) let be the position of the q-th target in spherical coordinates, moving with velocity v q relative to the radar. Using far-field approximation for the q-th target, the round-trip time delay between a transmitter positioned at the origin and the receiver positioned at a coordinate l is given by τlq=2(Rq+vqt)+ld sin θqc, where d is the distance between antenna elements (usually half the wavelength), arranged in a linear constellation. The delay time τ lq This generates a uniform phase progression across antenna elements, which improves the estimation of the angle θ. q This is made possible by FFT in a spatial area. Thus, the 2D position (distance and angle) and the velocity of targets can be estimated by a 3D FFT. The third angle FFT is implemented in processing block 150 of the exemplary radar signal processing block diagram by Fig. 1 executed.

[0044] Further conventional automotive radar processing can include target clustering 160, target tracking 170 and optional sensor fusion 180 with sensor data from other environmental sensor types (e.g. camera, lidar, etc.).

[0045] As mentioned previously, high-resolution radar systems (e.g., MIMO radar systems) use multiple transmit and / or receive channels. However, the number of possible transmit and receive channels for a single radar MMIC chip is limited. Therefore, multiple MMIC chips can be cascaded, i.e., several radar MMIC chips can be coupled, with one of the MMIC chips acting as a master and providing a system clock for clock synchronization, a trigger signal to provide a pulse start signal, and a high-frequency signal for phase synchronization, etc. The other MMIC chips (slaves) provide additional transmit / receive channels for the radar system. This disclosure proposes an efficient concept for distributing radar signal processing among different radar MMIC chips for target differentiation in distance, velocity, and direction.

[0046] Fig. Figure 4 shows an example of the construction of a radar device 400 for distributing the radar signal processing.

[0047] The radar device 400 comprises a first radar MMIC 410-1 and a second radar MMIC 410-2. The first and second radar MMICs 410-1 and 410-2 can be cascaded. The radar MMIC 410-1 can be coupled to first antennas (No. 1, No. 2, No. 3) of an antenna array 414, and the second radar MMIC 410-2 can be coupled to different second antennas (No. 4, No. 5, No. 6) of the same antenna array. The antenna array 414 can, for example, be a linear antenna array. The first radar MMIC 410-1 is configured to process initial received signals from the first antennas (No. 1, No. 2, No. 3). In the example shown, the Radar-MMIC 410-1 comprises three receiver chains. Each receiver chain can, for example, include a low-noise amplifier, a mixer, and an analog-to-digital converter.A person skilled in the art who benefits from the present disclosure will recognize that the number of receive chains can vary and that the radar MMIC 410-1 can also include one or more transmit chains with an integrated power amplifier (PA), a synthesizer capable of providing fast ramps for FMCW radar operation, integrated clock references, and temperature sensors. The first radar MMIC 410-1 includes a signal processing circuit arrangement configured to determine a first combined range / Doppler map based on the (sampled) first received signals and to determine a first subregion of the first combined range / Doppler map based on predetermined criteria. For example, the predetermined criteria may include amplitude or energy levels of range / Doppler map cells (FFT bins) above or below a predefined threshold.If the amplitude of the distance / Doppler map at an estimated distance / velocity is greater than a certain (selection) threshold, a peak of a first subregion of interest can be considered detected. One or more such detected peaks can constitute a subregion of interest.

[0048] In some embodiments, the first radar MMIC 410-1 is configured to determine an antenna-specific range / Doppler map for each of the first received signals from the active receive channels assigned to the first radar MMIC 410-1. Each of the first received signals originates from a different antenna of the first antennas (No. 1, No. 2, No. 3). Thus, the first radar MMIC 410-1 is configured to determine an antenna-specific range / Doppler map for each antenna (No. 1, No. 2, No. 3) assigned to the first radar MMIC 410-1. The first radar MMIC 410-1 is further designed to generate the first combined range / Doppler map based on a linear combination of the antenna-specific range / Doppler maps, such as a connected or disconnected summation or integration of the antenna-specific range / Doppler maps of the first received signals.

[0049] Likewise, the second radar MMIC 410-2 is configured to process second received signals from second antennas (No. 4, No. 5, No. 6) of the antenna array 414. In some implementations, the hardware of the second radar MMIC 410-2 is essentially the same as that of the first radar MMIC 410-1. The second radar MMIC 410-2 includes a signal processing circuitry configured to determine a second combined range / Doppler map based on the (sampled) second received signals and to determine a second subregion of the second range / Doppler map based on criteria of interest. The second radar MMIC 410-2 can perform the same range / Doppler processing as the first radar MMIC 410-1, but it uses the second received signals instead of the first received signals.For example, if the amplitude of the combined distance / Doppler map is greater than a certain threshold at an estimated distance / velocity, a peak of a second subregion of interest will be detected. Again, one or more of the detected peaks can constitute a subregion of interest.

[0050] In some embodiments, the second radar MMIC 410-2 can be configured to determine an antenna-specific range / Doppler map for each of the second received signals. Each of the second received signals originates from a different antenna of the second antennas (No. 4, No. 5, No. 6). The second radar MMIC 410-1 can be configured to determine the second combined range / Doppler map based on a linear combination, such as a summation or integration of the antenna-specific range / Doppler maps of the second received signals.

[0051] The radar device 400 further comprises a data interface 420 that couples the first radar MMIC 410-1 with the second radar MMIC 410-2. The data interface (420) can be configured to forward information indicating the detected first and / or second range / Doppler map subregions to a common processor for further processing. In some implementations, the common processor can be a remote processor or an MMIC 410-3 different from the first and second radar MMICs 410-1, 410-2. Alternatively, a processor implemented in one of the first and second radar MMICs 410-1, 410-2 can act as the common processor. In some implementations, the data interface 420 can be a unidirectional data interface.In some implementations, the 420 data interface can be based on the Serial Peripheral Interface (SPI), which is a synchronous serial communication interface. However, a person skilled in the art who benefits from the present disclosure will recognize that other implementations of high-speed inter-IC communication interfaces are also possible.

[0052] In some implementations, cell or bin indices (p, n) of the detected first and / or second subregion can be forwarded to the common processor via data interface 420. Bin indices of subregions of no interest (undetected subregions) can be selected not to be forwarded to the common processor. This reduces communication bandwidth and / or speeds up processing, while still allowing the common processor to reconstruct the detected subregions. Whether the first, second, or both detected subregions are selected for forwarding via data interface 420 depends on the common processor implementation.In some embodiments, it may suffice to forward only information relating to the first detected subregion(s) to the second radar MMIC 410-2, provided the second radar MMIC 410-2 acts as the common processor. Optionally, complex amplitude values ​​associated with the bin indices of the detected first and / or second subregions can also be forwarded to the common processor via data interface 420. This can be performed across all antennas of the respective radar MMIC, allowing a discrete Fourier transform (FFT) to be performed on the detected subregions at a later time for angle estimation.

[0053] The common processor can be configured to combine the first and second signal subregions, for example, via a logical OR combination of the distance / Doppler cells (FFT bins), to obtain one or more combined subregions. For example, each of the distance / Doppler cells of the first subregion can be represented as a logical value 1 in a first logical map, while the distance / Doppler cells that are not within the first subregion can be represented as a logical value 0. Similarly, the distance / Doppler cells of the second subregion can be represented as a logical value 1 in a second logical map, while the distance / Doppler cells that are not within the second subregion can be represented as a logical value 0.A combined logical map can be obtained by ORing the logical values ​​of the respective first and second logical maps for each distance / Doppler cell. In this map, the combined subregions are represented by the resulting logical values ​​of 1. Based on one or more combined subregions and additional phase information (via antennas) assigned to these subregions, a third discrete Fourier transform via antennas can then be performed for directional or angular processing.

[0054] An example of detected subregional data that can be exchanged via data interface 420 is in Fig. 5 shown.

[0055] Fig. Figure 5 represents an exemplary FFT spectrum of a receiving antenna with 16 FFT bins (from index 0 to 15). Each distance / Doppler cell or FFT bin i (i=0...15) has an associated complex value (a i , b i ) and an amplitude A i on. The amplitude values ​​A i are compared to a fixed or adaptive threshold th. If A iIf the corresponding distance / Doppler cell i is detected or considered to belong to a subregion of interest, then the corresponding distance / Doppler cell i is considered detected. In the example shown, distance / Doppler cells 1, 2, 3, 4, 5, 12, 13, 14, and 15 are detected and thus form a subregion of interest. A metadata vector (binary map) of length 16 can be forwarded, showing the detected distance / Doppler cells 1, 2, 3, 4, 5, 12, 13, 14, and 15. Here, the metadata vector has a "1" at positions 1, 2, 3, 4, 5, 12, 13, 14, and 15, and a "0" elsewhere. The "1" in the metadata vector indicates the subregion(s) of interest. Furthermore, the complex values ​​(a i , b iThe values ​​assigned to the detected distance / Doppler cells 1, 2, 3, 4, 5, 12, 13, 14, and 15 are forwarded via data interface 420. It is not necessary to forward the complex values ​​assigned to the undetected distance / Doppler cells 0, 6, 7, 8, 9, 10, and 11. According to the example of Fig. 5 can only accept complex values ​​(a i , b i The amplitude and phase of the detected distance / Doppler cells are transmitted (via the receiving antenna), while the logical values ​​(metadata) for all distance / Doppler cells can be transmitted. Since the complex values ​​(a i , b i ) exhibiting the respective phase of the received signal, the data format example shown includes Fig. 5 also inherently contains information indicating phases or phase progressions of the first and / or second received signals, which can be used to obtain spatial information about the subregion(s) of interest.

[0056] Several such FFT spectra or range / Doppler maps, each assigned to a respective receiving antenna, can be integrated coherently or non-coherently in each of the first and second radar MMICS 410-1 and 410-2. Coherent integration is performed before amplitude detection and thus retains phase information, while non-coherent integration is performed after amplitude detection and therefore lacks phase information. Fig. 5 could therefore also be considered as an FFT spectrum resulting from a connected or disconnected integration of several antenna-specific FFT spectra.

[0057] In some implementations, the second radar MMIC 410-2 may be configured to implement the common processor. In such cases, the first radar MMIC 410-1 may be configured to relay information indicating the phases of the initial received signals (phase progression across antenna elements No. 1, No. 2, No. 3) to the radar MMIC 410-2 via the data interface 420. As described above, such phase information can inherently be complex values ​​(a i , b i ), assigned to the detected bins / subregions. The complex values ​​(a i , b iThe detected distance / Doppler cells across all first antenna elements No. 1, No. 2, No. 3 can be used to perform spatial or angular FTT. Then, the second radar MMIC 410-2 can be configured to determine spatial directions (e.g., azimuth or elevation angles) of the detected subregions based on the combined detected subregions from the first and second radar MMICs 410-1, 410-2, and based on the phases of the first and second received signals. Here, the complex values ​​(a i , b i The detected distance / Doppler cells across all antenna elements No. 1, No. 2, No. 3, No. 4, No. 5, and No. 6 can be used to perform the spatial or angular FFT. Thus, an FFT can be performed on the combined detected subregions across all antennas of the antenna array to estimate the angle(s).

[0058] An example signal flow according to such implementations is shown in Fig. 6a shown.

[0059] Fig. Figure 6a shows an exemplary time-based signal processing sequence of the first and second radar MMICs 410-1 and 410-2. Here, the second radar MMIC 410-2 acts as the master MMIC, while the first radar MMIC 410-1 acts as the slave MMIC. The FMCW signal ramps are generated in the second radar MMIC 410-2 and distributed to the first radar MMIC 410-1. Thus, both radar MMICs 410-1 and 410-2 use the same FMCW signal ramps for transmission and reception in a synchronized manner.

[0060] During a first time interval t FFT1 Both radar MMICs 410-1 and 410-2 perform a first FFT (distance FFT) on their respective (sampled) received signals. This is done for each receive channel.

[0061] During a subsequent second time interval t FFT2Both radar MMICs 410-1 and 410-2 perform a second FFT (Doppler FFT) over the slow time (subsequent pulses). This is repeated for each receive channel. In this way, range / Doppler maps can be obtained for all respective receive channels. When a target is illuminated by the radar beam, it typically reflects numerous pulses. The detection probability can be improved by summing or integrating all range / Doppler map data from all transmit-receive antenna pairs. In the example shown, each radar MMIC 410-1 and 410-2 is coupled to eight receive antennas. Thus, a virtual antenna array of eight transmit antennas and sixteen receive antennas can be formed using the radar MMICs 410-1 and 410-2.

[0062] In the example shown, both radar MMICs 410-1 and 410-2 perform non-coherent integration (NCI) of the range / Doppler maps for all respective receive and transmit channels, assigned to the respective radar MMIC, during a subsequent time interval t NCI_local out of.

[0063] During a subsequent time interval t localDet Both radar MMCIs 410-1 and 410-2 detect respective subregions of the respective combined (NCI) range / Doppler map based on the criteria of interest and provide the logical representation of whether a range / Doppler cell (FFT bin) lies within a detected subregion or not. As mentioned previously, the subregions can, for example, include range / Doppler cells assigned to the NCI amplitudes above a certain threshold. In a subsequent short communication time interval t DetCommThe information from the detected range / Doppler map subregions of the first radar MMIC 410-1 is communicated to the second radar MMIC 410-2 via data interface 420. This can be done, for example, according to the exemplary data format of Fig. 5 will be executed. The metadata vector and optionally the complex values ​​(a i , b iThe data (for all Tx-Rx antenna pairs of the first radar MMIC 410-1), assigned to the detected range / Doppler cells, can thus be forwarded from the first radar MMIC 410-1 to the second radar MMIC 410-2 via data interface 420. As described above, transmitted information relating to the detected range / Doppler map subregions can include, for each range / Doppler cell within the subregion, the amplitude and phase information and the 1-bit information indicating whether the range / Doppler cell lies within a subregion. For range / Doppler cells that do not lie within the detected subregions, only the 1-bit information indicating whether the range / Doppler cell lies within a subregion can be transmitted.It should be noted that the amount of data required to transmit the detected distance / Doppler map subregions is much lower than transmitting the distance / Doppler map data from all antennas upstream of the NCI.

[0064] During a subsequent time interval t finalDet The second radar MMIC 410-2 can combine the detected range / Doppler map subregions of the first radar MMIC and the detected range / Doppler map subregions of the second radar MMIC via a logical OR to obtain combined detected subregions.

[0065] During a subsequent short time interval t finalDetThe second radar MMIC 410-2 can request additional phase information from the first radar MMIC 410-1, assigned to combined detected subregions that were not within the previously detected range / Doppler map subregions of the first radar MMIC. This additional phase information, assigned to the missing subregions, can be transmitted, for example, from the first radar MMIC 410-1 to the second radar MMIC 410-2 via data interface 420 in the form of complex values ​​(a i , b i ) will be forwarded.

[0066] The requested additional phase information is then transmitted from the first radar MMIC 410-1 to the second radar MMIC 410-2 during the subsequent time interval t. AntComm transmitted.

[0067] Then the second radar MMIC 410-2 received the information that allows the directional or angular information for the combined subregions to be determined via a third (angular) FFT over all antennas during the time interval t DoA to generate distance, velocity, and angle information of the detected (combined) subregions, which can then be forwarded to a remote processor, such as a vehicle's ECU. Alternatively, the third (angle) FFT could be performed on the external processor, such as the ECU.

[0068] The exemplary temporal signal processing of Fig. 6b differs from Fig. 6a by performing the third (angle) FFT alternatively or additionally on the first radar MMIC 410-1 during the time interval t DoA is executed. In Fig. 6b the second radar-MMIC 410-2 is configured to transmit the combined subregions and associated information, indicating phases from the second received signals, to the first radar-MMIC 410-1 via the data interface 420 during the time interval t AntComm to forward. Then the first radar MMIC 410-1 can determine the spatial directions of the combined subregions (target objects) based on an FFT on distance / Doppler cells of the combined subregions via the first and second antennas.

[0069] Fig. 7a, b represent flowcharts according to the temporal signal processing profiles of the Fig. 6a, b. In Fig. 7a, b the right column corresponds to steps performed in the master device (e.g. second radar MMIC 410-2), while the left column corresponds to steps performed in the slave device (e.g. first radar MMIC 410-1).

[0070] In the first steps 710-1 and 710-2, both radar MMICs 410-1 and 410-2 perform a first FFT (distance FFT) on their respective received signals. This can be performed for each received channel. In the subsequent second steps 720-1 and 720-2, both radar MMICs 410-1 and 410-2 perform a second FFT (Doppler FFT) over the slow time. This can again be performed for each received channel. Thus, after the second steps 720-1 and 720-2, receive-channel-specific range / Doppler maps are available in both radar MMICs 410-1 and 410-2. In subsequent third steps 730-1, 730-2, both radar MMICs 410-1, 410-2 perform non-contiguous integration (NCI) from their respective receive-channel-specific range / Doppler maps for all respective receive (and transmit) channels to obtain respective partially integrated (NCI) range / Doppler maps.

[0071] In subsequent fourth steps, 740-1 and 740-2, both radar MMICs 410-1 and 410-2 detect respective range / Doppler cells (peaks) of their respective partially integrated (NCI) range / Doppler maps based on criteria of interest, e.g., according to a predetermined selection criterion. The detected range / Doppler cells of the first radar MMIC 410-1 are then communicated to the second radar MMIC 410-2 via data interface 420. As described in Fig. As shown in Figure 7a, the detected range / Doppler cells of the first radar MMIC 410-1 can already be combined (logical OR) with detected range / Doppler cells of another radar MMIC (not shown). In this way, a cascade of different radar MMICs can be implemented, with each radar MMIC detecting its respective range / Doppler cells and forwarding them to the next radar MMIC in the cascade.

[0072] A binary map (0s and 1s showing the respective subregions) can be provided from any MMIC to the next MMIC in the cascade, and each MMIC receiving the binary map can further combine the binary maps at 750-1.

[0073] Finally, the communication master can generate a final binary map at 750-2, displaying the final detected distance / Doppler cells, by combining the received binary map with its own. This information about the final detected distance / Doppler cells, displayed by the final binary map, can then be distributed to each of the MMICs with a request to extract the associated phase (and amplitude) information at 765-1 and send it to the communication master. The communication master can then either calculate the angle FFT or send the data to an external ECU for calculation of the angle FFT at 770-2.

[0074] In the flowchart of Fig. 7b the information on the final detected distance / Doppler cells, displayed by the final binary map, is distributed to each of the MMICs with a request to extract and send the associated phase information (and amplitude information). Fig. 7b differs from Fig. 7a by the fact that the individual MMICs do not send the associated phase information (phase progression via antennas) to the communication master, but for example to an external ECU. The ECU can then calculate the angle FFT based on the information received from the MMICs.

[0075] In the flowchart of Fig. In step 7c, the information on the final detected range / Doppler cells, displayed by the final binary map, is distributed by the second radar MMIC 410-2 (master) to each of the (slave) MMICs with a request to extract the respective associated phase (and amplitude) information and send it back to the second radar MMIC 410-2 via data interface 420. In step 765-2, the second radar MMIC 410-2 can then calculate the angle FFT with respect to the final detected range / Doppler cells based on the associated phase information received from the other MMICs. The information on the final detected range / Doppler cells, displayed by the final binary map, along with the associated angle information obtained from step 765-2, can then be forwarded, for example, to an external ECU via an Ethernet link 770-2. Thus, the flowchart of Fig. Figure 7c shows an embodiment with angle processing, which is performed by the second radar MMIC 410-2.

[0076] In the flowchart of Fig. In step 7D, the information about the final detected range / Doppler cells, displayed by the final binary map (i.e., the result of step 750-2), can then be distributed to the other (slave) MMICs. This distribution can involve a selection or assignment of which other (slave) MMIC should calculate which angular information. In other words, the second radar MMIC 410-2 (master) can select the first radar MMIC 410-1 to calculate initial angular information (via an angular FFT) for a first subset of the final detected range / Doppler cells (peaks), while the second radar MMIC 410-2 can be selected to calculate secondary angular information (via an angular FFT) for a second subset of the final detected range / Doppler cells (peaks).Similarly, a third radar MMIC can be selected to compute third angular information for a third subset of the final detected range / Doppler cells. The selection can be based, for example, on a computation criterion, such as a computation load balancing criterion. The person skilled in the art, benefiting from the present disclosure, recognizes that the radar MMICs can share phase information associated with the assigned range / Doppler cells via the data interface 420. For example, phase information associated with the first subset of the final detected range / Doppler cells can be provided to the first radar MMIC 410-1 by the second radar MMIC 410-2 (and any further radar MMICs).Phase information, assigned to the second subset of the final detected range / Doppler cells, can be provided to the second radar MMIC 410-2 by the first radar MMIC 410-1 (and any further radar MMICs). Information about the different subsets of final detected range / Doppler cells (peaks), along with the associated angle information, obtained from steps 765-1 and 765-2, can then be forwarded, for example, to an external ECU via an Ethernet link 770-2. Thus, the flowchart of... Fig. Figure 7d shows an embodiment with distributed angle processing under the different radar MMICs 410-1, 410-2.

[0077] The concept of distributed processing of Fig. 7a-d can then be replaced by a Fig. The concept of distributed signal processing shown in section 7e can be further improved with regard to latency.

[0078] Again in Fig. 7e corresponds to the right column of steps performed in the master device (e.g., second radar MMIC 410-2), while the left column corresponds to steps performed in the slave device (e.g., first radar MMIC 410-1).

[0079] In the first steps 710-1 and 710-2, both radar MMICs 410-1 and 410-2 perform a first FFT (distance FFT) on their respective received signals. This can be performed for each received channel. In the subsequent second steps 720-1 and 720-2, both radar MMICs 410-1 and 410-2 perform a second FFT (Doppler FFT) over the slow time. This can again be performed for each received channel. Thus, after the second steps 720-1 and 720-2, receive-channel-specific range / Doppler maps are available in both radar MMICs 410-1 and 410-2. In subsequent third steps 730-1, 730-2, both radar MMICs 410-1, 410-2 can perform a contiguous integration (IC) or non-contiguous integration (NCI) of their respective receive-channel-specific range / Doppler maps for all respective receive (and transmit) channels to obtain respective combined range / Doppler maps.“Combined” here refers to a combination via the respective assigned receiving channels through coherent integration (CI) or non-coherent integration (NCI).

[0080] In subsequent steps 735-1 and 735-2, both radar MMICs 410-1 and 410-2 can detect respective categories of range / Doppler cells from the combined range / Doppler map based on a plurality of predetermined criteria. In some embodiments, there can be three categories of range / Doppler cells: selected range / Doppler cells, confirmable range / Doppler cells, and unselected range / Doppler cells. The selected range / Doppler cells meet a predetermined selection criterion and can be considered final peak selections. The confirmable range / Doppler cells meet a predetermined confirmation criterion and require further evaluation. The unselected range / Doppler cells meet neither the predetermined selection criterion nor the predetermined confirmation criterion and can be considered final and discarded.

[0081] In some embodiments, the predetermined selection criterion may include a distance / Doppler cell amplitude or energy level above a first threshold. That is, the predetermined selection criterion can be met if the amplitude or energy level of a distance / Doppler cell in a combined distance / Doppler map is equal to or greater than the first threshold. In this case, the distance / Doppler cell can be classified as a selected distance / Doppler cell. The predetermined confirmation criterion may include a distance / Doppler cell amplitude or energy level below the first threshold and above a second threshold. That is, the predetermined confirmation criterion can be met if the amplitude or energy level of a distance / Doppler cell in a combined distance / Doppler map is between the second and first thresholds.In this case, the distance / Doppler cell can be classified as a confirmatory distance / Doppler cell. Amplitude or energy levels of unselected distance / Doppler cells may be below the second threshold.

[0082] In alternative embodiments, the predetermined confirmation criterion can include a distance level above a first threshold. That is, the predetermined confirmation criterion can be met if a distance level of a distance / Doppler cell in a combined distance / Doppler map is equal to or greater than the first threshold. In this case, the distance / Doppler cell can be classified as a confirmable distance / Doppler cell. The predetermined selection criterion can also include a distance level below the first threshold and above a second threshold. That is, the predetermined selection criterion can be met if a distance level of a distance / Doppler cell in a combined distance / Doppler map is between the second and first thresholds. In this case, the distance / Doppler cell can be classified as a selected distance / Doppler cell.Distance levels of unselected distance / Doppler cells may be below the second threshold.

[0083] As can be seen, the confirmatory range / Doppler cells identified by the radar MMICs 410-1 and 410-2 require additional (external) evaluation or confirmation to determine whether they are ultimately classified as selected or unselected range / Doppler cells. Selected range / Doppler cells can indicate a target object, while unselected range / Doppler cells can be disregarded during target detection. A person skilled in the art who benefits from the present disclosure recognizes that there may also be embodiments that use fewer categories of range / Doppler cells, e.g., only confirmatory range / Doppler cells or confirmatory range / Doppler cells and unselected range / Doppler cells.

[0084] In step 735-1, the first radar IC 410-1 can locally determine the first selected range / Doppler cells of the respective first combined range / Doppler map that meet the predetermined selection criterion. Furthermore, the first radar IC 410-1 can locally determine the first verifiable range / Doppler cells of the first combined range / Doppler map that meet a predetermined verification criterion. In addition, the first radar IC 410-1 can locally determine the first unselected range / Doppler cells of the first combined range / Doppler map that meet neither the predetermined selection criterion nor the predetermined verification criterion. Likewise, in step 735-2, the second radar MMIC 410-2 can locally determine the second selected range / Doppler cells of the respective second combined range / Doppler map that meet the predetermined selection criterion.Furthermore, the second radar MMIC 410-2 can locally determine second verifiable range / Doppler cells of the second combined range / Doppler map that meet the predetermined verification criterion. In addition, the second radar MMIC 410-2 can locally determine second unselected range / Doppler cells of the second combined range / Doppler map that meet neither the predetermined selection criterion nor the predetermined verification criterion. A person skilled in the art who benefits from the present disclosure recognizes that more than the two radar MMICs 410-1 and 410-2 may be involved.

[0085] As shown in Figure 737, the range / Doppler cells of each category coming from the first radar MMIC 410-1 can already be logically combined (e.g., by logical OR) with corresponding range / Doppler cells of the same category coming from another radar MMIC (not shown). In this way, a cascade of different radar MMICs can be implemented, with each radar MMIC detecting corresponding range / Doppler cells of different categories (selected, acknowledgable, unselected) and forwarding them to the next radar MMIC in the cascade. For each category, a binary map (0s and 1s displaying the respective classified range / Doppler cells) can be provided from each MMIC to the next MMIC in the cascade, and each MMIC receiving the binary map can further combine the binary maps.For example, in an embodiment comprising only two radar MMICs 410-1 and 410-2, the second radar MMIC 410-2 can combine the first and second selected range / Doppler cells via a logical OR to obtain a combined set of selected range / Doppler cells (as final peak detections), combine the first and second confirmatory range / Doppler cells via a logical OR to obtain a combined set of confirmatory range / Doppler cells (as confirmatory peak detections), and combine the first and second unselected range / Doppler cells via a logical OR to obtain a combined set of unselected range / Doppler cells. Other logical combinations are also possible.

[0086] In the 738, the communication master (here: the second radar IC 410-2) can communicate a binary map corresponding to the combined set of verifiable range / Doppler cells (verifiable peak detections) to each of the MMICs, requesting them to extract the associated (complex) values ​​(e.g., amplitude and phase) of the respective combined range / Doppler maps and send them to the communication master for global coherent or incoherent integration. That is, amplitude and phase information for each range / Doppler cell of the combined set of verifiable range / Doppler cells (verifiable peak detections) can be requested by the slaves through the communication master.

[0087] In the 739 configuration, each radar MMIC (complex) communicates values ​​from its radar MMIC-specific combined range / Doppler map, corresponding to the combined set of verifiable range / Doppler cells, to the communication master (here: second radar MIC 410-2). This means that amplitude and phase information from each range / Doppler cell of the combined set of verifiable range / Doppler cells (verifiable peak detections) can be communicated from the slaves to the communication master.

[0088] In the 745-2, the communications master (here: second radar IC 410-2) performs coherent or non-coherent integration of the received (complex) values ​​of the radar MMIC-specific combined range / Doppler maps, corresponding to the combined set of verifiable range / Doppler cells (verifiable peak detections), to obtain summed or integrated values ​​of the combined set of verifiable range / Doppler cells. This means that amplitude (and phase) information from each range / Doppler cell of the combined set of verifiable range / Doppler cells can be integrated coherently or non-coherently across all antennas and across all radar MMICs. Therefore, the second radar IC 410-2 at 745-2 performs a global coherent or incoherent integration of the combined set of confirmatory range / Doppler cells.Furthermore, the second radar IC 410-2 at 745-2 can select summed or integrated values ​​of the combined set of confirmable range / Doppler cells that exceed a predefined threshold (e.g., the selection threshold or another threshold) as additional selected range / Doppler cells (additional final peak detections). Summed or integrated values ​​of the combined set of confirmable range / Doppler cells that do not exceed the predefined threshold can be discarded as unselected range / Doppler cells. Together with the previously (or subsequently) determined combined set of selected range / Doppler cells, the additional selected range / Doppler cells (based on confirmation) can form a final set of selected range / Doppler cells (final peak detections).

[0089] At step 760, the information on the final detected range / Doppler cells, displayed by the final binary map, can then be distributed by the second radar MMIC 410-2 (master) to each of the (slave) MMICs with a request to extract the respective associated phase (and amplitude) information and send it back to the second radar MMIC 410-2 via data interface 420. In step 765-2, the second radar MMIC 410-2 can then calculate the angle FFT with respect to the final set of selected range / Doppler cells based on the associated phase information received from the other MMICs. The information about the final detected distance / Doppler cells, displayed by the final binary map, along with the associated angle information obtained from step 765-2, can then be forwarded, for example, to an external ECU via an Ethernet link 770-2.

[0090] Thus, the flowchart of Fig. Figure 7e shows an embodiment with angle processing, which is performed by the second radar MMIC 410-2.

[0091] The in Fig. The embodiment shown in section 7e proposes to identify three categories of distance / Doppler cells (although fewer categories are also conceivable). - No. 1: Distance / Doppler cells that meet a selection criterion and for which it is not necessary to forward to an external processing device for shared use for confirmation. - No. 2: Distance / Doppler cells that meet a confirmation criterion and require confirmation by information from an external processing element. - No. 3: Distance / Doppler cells that do not meet these criteria and are not selected solely based on local information. - Performing a global NCI (or CI) within the master processing unit (second radar MMIC 410-2) using Category 2 information from slave processing units (e.g., first radar MMIC 410-1) - Performing final FFT peak selection for the entire data cube using category 2 distance / Doppler cells received from the master. - Communicating results to each distributed processing element (the OR between the list of peaks from category 1 and the FFT peak selection via the global NCI of category 2) as selected FFT peaks - Receiving data from selected FFT peaks from other processing elements and subsequently performing DoA locally. - Then send the FFT peak information to the remote ECU for post-processing.

[0092] Thus, only information from distance / Doppler cells that require external confirmation can be sent to an external processing element for external verification, which combines NCI or CI with the distance / Doppler cells of this processor and then performs an FFT peak detection algorithm on the entire distance / Doppler map to confirm which ones have been selected.

[0093] The person skilled in the art who benefits from the present disclosure recognizes that the embodiment of Fig. 7e can be further modified. For example, a different processor (e.g., Radar-MMIC 410-3 or ECU) than the second Radar-MMIC 410-2 could perform the confirmation by executing a global NCI (or CI) using Category 2 information (confirmable range / Doppler cells) from Radar-MMICs 410-1 and 410-2. The calculation of the angle information with respect to the final peak detections could be performed in accordance with one of the embodiments of the Fig. 7A-d will be carried out.

[0094] Therefore, a device 400 for detecting radar targets is proposed in the present disclosure. The device 400 comprises a first radar MMIC 410-1 configured to Receiving a plurality of first received signals from first antennas (No. 1, No. 2, No. 3) of an antenna array 414; Determining a first combined range / Doppler map by combining range / Doppler maps from each of the first antennas (No. 1, No. 2, No. 3) and determining first verifiable range / Doppler cells of the first combined range / Doppler map that meet a predetermined verification criterion. The device 400 further comprises a second radar MMIC 410-2 configured to Receiving a plurality of second receive signals from second antennas (No. 4, No. 5, No. 6) of the antenna array 414; Determining a second combined range / Doppler map by combining range / Doppler maps of each of the second antennas (No. 4, No. 5, No. 6), and to Determining the second confirmable distance / Doppler cells of the second combined distance / Doppler map that meet the predetermined confirmation criterion. The device 400 further comprises a processing circuit arrangement 410-2, 410-3 configured for Combining the first and second confirmatory distance / Doppler cells to obtain a combined set of confirmatory distance / Doppler cells; Summing the values ​​of the first and second combined distance / Doppler maps, corresponding to the combined set of confirmatory distance / Doppler cells, to obtain summed values ​​of the combined confirmatory distance / Doppler cells, and for

[0095] Selecting summed values ​​of the combined set of confirmatory distance / Doppler cells that exceed a predefined selection threshold as selected distance / Doppler cells for further processing, such as target detection.

[0096] Two examples of cascaded radar MMIC layouts according to embodiments of the present disclosure are described in Fig. 8a, b shown.

[0097] Fig. Figure 8a shows an implementation with three radar MMICs 410-1, 410-2, and 410-3 acting as receiver ICs and another radar MMIC 810-4 acting as a transmitter IC. Each of the radar MMICs 410-1, 410-2, and 410-3 is connected to a subset of receiving antennas from a receiving antenna array (not shown). The radar MMIC 810-4 is connected to transmitting antennas from a transmitting antenna array (not shown). The radar MMIC 410-2 provides its local oscillator (LO) signal as a synchronization signal to the other radar MMICs 410-1, 410-3, and 810-4. All radar MMICs 410-1, 410-2, 410-3, and 810-4 are connected via SPI. While radar MMIC 410-3 acts as an SPI master, the others act as SPI slaves. A communication cascade extends from radar MMIC 410-1 through radar MMIC 410-2 to radar MMIC 410-3.

[0098] In an exemplary implementation, the second radar MMIC 410-2 can combine the detected range / Doppler map subregions (for example, the binary map thereof), received from the first radar MMIC 410-1, with its own detected range / Doppler map subregions using a logical OR operation to obtain combined subregions. This result is then passed to the third radar MMIC 410-3 for further combination with its own detected range / Doppler map subregions to obtain the complete detected subregions. This information on the final detected subregions, displayed by the final binary map, can then be distributed to each of the MMICs 410-1 and 410-2 with a request to extract the associated phase information and send it to the third radar MMIC 410-3. The third radar MMIC 410-3 can then either calculate the final angle FFT or send the data to an external ECU.

[0099] Alternatively, in a first round, the binary maps of detected range / Doppler map subregions are transmitted along with the phase information for each detected range / Doppler map subregion. The second radar MMIC 410-2 can combine the binary map received from the first radar MMIC 410-1 with its own binary map using a logical OR operation to obtain combined subregions and forward this result to the third radar MMIC 410-3 for further combination with its own binary map to obtain the final detected subregions. In a second round, each MMIC can provide additional phase information for these final detected subregions that were not among its own detected range / Doppler map subregions in the first round.

[0100] In the example of Fig. 8a The MMICs are cascaded in such a way that no dedicated processing master exists. Each processing element processes data independently to identify the respective candidate FFT peaks (detected range / Doppler map subregions) to be sent to the central ECU. Each MMIC collectively uses its respective list of candidate FFT peaks to generate a combined list of candidate peaks. Each of these sends its own FFT peaks and a list of FFT peaks found by the other processing element(s) in the radar. There is no master device, but there could be a device used to manage external communication (i.e., sending information describing the FFT peaks).The cascading concept is based on a data cascade link to a device that manages communication (communication master) and a link used to send commands from the communication master to the other devices. The link is shown as an SPI, but can have any other form (circular ring, etc.).

[0101] Fig. 8b shows an implementation according to the flowchart of Fig. 7b. Here, the individual MMICs do not send the phase information of the detected distance / Doppler map subregions to a communication master, but to an external ECU. The ECU can then calculate the angle FFT based on the information received from the MMICs, which describes the detected distance / Doppler map subregions.

[0102] The proposed concept reduces latency because intermediate results do not need to be forwarded to a master device to select which peak to transmit. The concept works the same when using compressed communication of distance / Doppler map subregions or FFT peaks.

[0103] The aspects and features mentioned and described along with one or more of the previously detailed examples and figures can also be combined with one or more of the other examples to replace an identical feature of the other example or to additionally introduce the feature into the other example.

[0104] Examples may also include, or refer to, a computer program that contains program code for performing one or more of the preceding procedures, when the computer program is executed on a computer or processor. Steps, operations, or processes of various procedures described above may be performed by programmed computers or processors. Examples may also include program storage devices, such as digital data storage media, that are machine-, processor-, or computer-readable and encode machine-executable, processor-executable, or computer-executable programs of instructions. The instructions perform or cause some or all of the steps of the procedures described above. The program storage devices may, for example,Digital storage devices, magnetic storage media such as magnetic disks and magnetic tapes, hard disk drives, or optically readable digital data storage media. Further examples may also include computers, processors, or control units programmed to perform the steps of the procedures described above, or (field) programmable logic arrays ((F)PLAs; (Field) Programmable Logic Arrays) or (field) programmable gate arrays ((F)PGAs; (Field) Programmable Gate Arrays) programmed to perform the steps of the procedures described above.

[0105] The descriptions and drawings illustrate only the principles of revelation. Furthermore, all examples presented here are expressly intended for illustrative purposes only, to assist the reader in understanding the principles of revelation and the concepts contributed by the inventor(s) to the advancement of technology. All statements herein concerning principles, aspects, and examples of revelation, as well as specific examples thereof, are intended to encompass their corresponding representations.

[0106] A functional block designated as a "means to..." that performs a specific function can refer to a circuit configured to perform that function. Thus, a "means to something" can be implemented as a "means configured for or suitable for something," e.g., a device or circuit configured for or suitable for the specific task.

[0107] The functions of various elements shown in the figures, including any functional blocks designated as "means," "means of providing a signal," "means of generating a signal," etc., may be implemented in the form of dedicated hardware, e.g., "a signal provider," "a signal processing unit," "a processor," "a controller," etc., as well as in hardware capable of executing software in conjunction with associated software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some or all of which may be shared.However, the term "processor" or "controller" is by no means limited to hardware capable solely of executing software, but can include digital signal processor (DSP) hardware, network processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), read-only memory (ROM) for storing software, random-access memory (RAM), and non-volatile memory. Other hardware, both conventional and / or custom-designed, may also be included.

[0108] A block diagram, for example, can represent a detailed circuit diagram that implements the principles of the disclosure. Similarly, a flowchart, a process flowchart, a state transition diagram, pseudocode, and the like can represent various processes, operations, or steps that are, for example, substantially represented in a computer-readable medium and thus executed by a computer or processor, irrespective of whether such a computer or processor is explicitly shown. Methods disclosed in the description or in the claims can be implemented by an apparatus comprising means for performing each of the respective steps of these methods.

[0109] It is understood that the disclosure of multiple actions, processes, operations, steps, or functions in the description or claims should not be interpreted as being in a specific order unless explicitly or implicitly stated otherwise, for example, for technical reasons. Therefore, the disclosure of multiple steps or functions does not restrict them to a specific order unless these steps or functions are not interchangeable for technical reasons. Furthermore, in some examples, a single action, function, process, operation, or step may include and / or be broken down into multiple sub-actions, functions, processes, operations, or steps. Such sub-steps may be included and form part of the disclosure of that single step unless explicitly excluded.

[0110] Furthermore, the following claims are hereby included in the detailed description, where each claim can stand alone as a separate example. Although each claim can stand alone as a separate example, it should be noted that—although a dependent claim may refer in the claims to a specific combination with one or more other claims—other examples may also include a combination of the dependent claim with the subject matter of any other dependent or independent claim. Such combinations are explicitly suggested here unless it is stated that a particular combination is not intended. Furthermore, features of a claim for any other independent claim are also to be included, even if that claim is not directly dependent on the independent claim.

Claims

[1] A radar device (400), comprising: a first radar IC (410-1) for processing first received signals from first antennas of an antenna array (414), wherein the first radar IC is configured to Determining a first combined distance / Doppler map by combining distance / Doppler maps of each of the first antennas of the antenna array, Determine the first selected distance / Doppler cells of the first combined distance / Doppler map that meet a predetermined selection criterion; Determine the first confirmable distance / Doppler cells of the first combined distance / Doppler map that meet a predetermined confirmation criterion; at least a second radar IC (410-2) for processing second received signals from second antennas of the antenna array (414), wherein the second radar IC is configured to Determining a second combined range / Doppler map by combining range / Doppler maps of each of the second antennas of the antenna array, Determine the second selected distance / Doppler cells of the second combined distance / Doppler map that meet the predetermined selection criterion; Determine the second confirmatory distance / Doppler cells of the second combined distance / Doppler map that meet the predetermined confirmation criterion; the first radar IC is trained to Communicating information displayed by the first confirmatory range / Doppler cells to the second radar IC (410-2); the second radar IC is designed to Determining a set of confirmatory distance / Doppler cells by logically combining the first and second confirmatory distance / Doppler cells, Communicating the set of confirmatory range / Doppler cells to the first radar IC (410-1) the first radar IC is trained to Communicating values ​​from the first combined range / Doppler map, corresponding to the set of verifiable range / Doppler cells, to the second radar IC, the second radar IC is designed to Performing a summation of values ​​from the first and second combined distance / Doppler maps corresponding to the set of confirmatory distance / Doppler cells to obtain summed values ​​of the set of confirmatory distance / Doppler cells; Selecting summed values ​​of the set of confirmatory distance / Doppler cells that exceed a predefined threshold as the third selected distance / Doppler cells and combining the third selected distance / Doppler cells with the first selected distance / Doppler cells and the second selected distance / Doppler cells to obtain collectively selected distance / Doppler cells; a data interface (420) configured to forward information indicating the collectively selected distance / Doppler cells to a common processor (410-1; 410-2; 410-3) for further processing. [2] The radar device (400) according to claim 1, wherein the first radar IC is configured to communicate information indicating the first confirmable range / Doppler cells to the second radar IC (410-2) and information indicating the first selected range / Doppler cells to the second radar IC (410-2). [3] The radar device (400) according to claim 1 or 2, wherein the first radar IC is configured to communicate binary information indicating the first selected range / Doppler cells and the first confirmable range / Doppler cells to the second radar IC (410-2). [4] The radar device (400) according to one of the preceding claims, wherein the second radar IC is configured to combine the first and second selected range / Doppler cells via a logical OR to obtain combined selected range / Doppler cells, and to combine the combined selected range / Doppler cells with the third selected range / Doppler cells via a logical OR to obtain the collectively selected range / Doppler cells. [5] The radar device (400) according to one of the preceding claims, wherein the predetermined selection criterion comprises a distance / Doppler cell amplitude or energy level above a first threshold and wherein the predetermined confirmation criterion comprises a distance / Doppler cell amplitude or energy level below the first threshold and above a second threshold. [6] The radar device (400) according to any one of claims 1 to 4, wherein the predetermined confirmation criterion comprises a distance level above a first threshold and wherein the predetermined selection criterion comprises a distance level below the first threshold and above a second threshold. [7] The radar device (400) according to one of the preceding claims, wherein the first radar IC is configured to combine the range / Doppler maps of each of the first antennas by coherent or non-coherent integration, and wherein the second radar IC is configured to combine the range / Doppler maps of each of the second antennas by coherent or non-coherent integration. [8] The radar device (400) according to one of the preceding claims, wherein the second radar IC is configured to perform the summation of values ​​of the first and second combined range / Doppler maps corresponding to the set of confirmatory range / Doppler cells by coherent or non-coherent integration. [9] The radar device (400) according to one of the preceding claims, wherein the information displayed by the collectively selected range / Doppler cells, which is forwarded to the common processor, includes phase information about the first and / or the second antenna, wherein the phase information is assigned to the collectively selected range / Doppler cells. [10] The radar device (400) according to claim 9, wherein the common processor (410-1; 410-2; 410-3) is configured to determine spatial directions of target objects based on phase information assigned to the collectively selected range / Doppler cells. [11] The radar device (400) according to claim 10, wherein the common processor (410-1; 410-2; 410-3) is configured to forward the collectively selected distance / Doppler cells and associated spatial directions to a central control unit. [12] The radar device (400) according to one of the preceding claims, wherein the second radar IC (410-2) is configured as the common processor. [13] The radar device (400) according to claim 12, wherein the second radar IC (410-2) is configured to transmit the collectively selected range / Doppler cells and associated phase information via the first and second antennas to an external processor. [14] The radar device (400) according to one of the preceding claims, configured to synchronize a signal processing of the first and second radar ICs (410-1; 410-2) using a common synchronization signal. [15] A method for detecting radar targets, the method comprising Receiving a plurality of first received signals from first antennas of an antenna array (414) with a first radar IC (410-1); Determining a first combined range / Doppler map by combining range / Doppler maps of each of the first antennas of the antenna array in the first radar IC (410-1); Determining the first selected range / Doppler cells of the first combined range / Doppler map that meet a predetermined confirmation criterion in the first radar IC (410-1); Determining the first verifiable range / Doppler cells of the first combined range / Doppler map that meet a predetermined verification criterion in the first radar IC (410-1); Receiving a plurality of second receive signals from second antennas of the antenna array (414) with a second radar IC (410-2); Determining a second combined range / Doppler map by combining range / Doppler maps of each of the second antennas of the antenna array in the second radar IC (410-2), Determining the second selected range / Doppler cells of the second combined range / Doppler map that meet the predetermined selection criterion in the second radar IC (410-2); Determining the second confirmable range / Doppler cells of the second combined range / Doppler map that meet the predetermined confirmation criterion in the second radar IC (410-2); Communicating information indicating the first confirmatory range / Doppler cells from the first to the second radar IC (410-2); Determining a set of confirmatory range / Doppler cells by logically combining the first and second confirmatory range / Doppler cells in the second radar IC (410-2); Communicating the set of confirmatory range / Doppler cells to the first radar IC (410-1); Communicating values ​​of the first combined range / Doppler map corresponding to the set of verifiable range / Doppler cells from the first to the second radar IC, Performing a summation of values ​​of the first and second combined range / Doppler maps corresponding to the set of confirmable range / Doppler cells to obtain summed values ​​of the set of confirmable range / Doppler cells in the second radar IC (410-2); Selecting summed values ​​of the set of confirmatory distance / Doppler cells that exceed a predefined threshold as the third selected distance / Doppler cells and combining the third selected distance / Doppler cells with the first and second selected distance / Doppler cells to obtain collectively selected distance / Doppler cells; Forwarding information indicating the collectively selected distance / Doppler cells to a common processor (410-1; 410-2; 410-3) for further processing. [16] The method according to claim 15, further comprising communicating information indicating the first selected range / Doppler cells to the second radar IC. [17] The method according to claims 15 to 16, further comprising determining spatial directions of target objects based on the collectively selected distance / Doppler cells and based on phases of the first and second received signals assigned to the collectively selected distance / Doppler cells. [18] The method according to any one of claims 15 to 17, further comprising detecting target objects based on the collectively selected distance / Doppler cells. [19] A method for detecting radar targets, the method encompassing Receiving a plurality of first received signals from first antennas of an antenna array (414); Determining a first combined range / Doppler map by combining range / Doppler maps of each of the first antennas; Determine the first confirmable distance / Doppler cells of the first combined distance / Doppler map that meet a predetermined confirmation criterion; Receiving a plurality of second received signals from second antennas of the antenna array (414); Determining a second combined range / Doppler map by combining range / Doppler maps from each of the second antennas; Determine the second confirmatory distance / Doppler cells of the second combined distance / Doppler map that meet the predetermined confirmation criterion; Combining the first and second confirmatory distance / Doppler cells to obtain a set of confirmatory distance / Doppler cells; Summing values ​​of the first and second combined distance / Doppler maps corresponding to the set of confirmatory distance / Doppler cells to obtain summed values ​​of the combined confirmatory distance / Doppler cells; Selecting summed values ​​of the set of confirmable distance / Doppler cells that exceed a predefined selection threshold as selected distance / Doppler cells. [20] The method according to claim 19, further comprising detecting target objects based on the selected distance / Doppler cells. [21] The method according to claim 19 or 20, wherein the predetermined selection threshold comprises a distance / Doppler cell amplitude or energy level threshold and wherein the predetermined confirmation criterion comprises a distance / Doppler cell amplitude or energy level below the predetermined selection threshold and above a lower threshold. [22] The method according to claim 19 or 20, wherein the predetermined confirmation criterion comprises a distance level above a first threshold and wherein the predetermined selection threshold comprises a distance level below the first threshold and above a second threshold. [23] The method according to any one of claims 19 to 22, further comprising determining spatial directions of target objects based on the selected distance / Doppler cells and based on phases of the first and second received signals assigned to the selected distance / Doppler cells.

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