Apparatus, radar system and method

Abstract

The invention relates to an apparatus, a radar system and a method. The present disclosure proposes an apparatus comprising circuitry configured to obtain a random delay for emission of a radar pulse and to control a radar sensor to emit the radar pulse at a point in time delayed by the random delay.

Description

Technical Field

[0001] The present disclosure relates to radar sensor control. Examples relate to devices, radar systems, and methods. Background Art

[0002] When multiple radar sensors are operated in close proximity, interference may occur between the radar sensors. These interferences may result in false or undetected targets. They may significantly affect the reliability and performance of radar-based detection. Existing methods for mitigating interference may focus mainly on interference cancellation algorithms, which reduce detection accuracy and increase the complexity of radar data processing. Therefore, there is a need for improved methods of mitigating interference. Summary of the invention

[0003] This requirement can be met by the subject matter of the independent claims.

[0004] Some aspects of the present disclosure relate to an apparatus including a circuit system configured to obtain a random delay for transmission of a radar pulse and to control a radar sensor to transmit the radar pulse at a time point delayed by the random delay.

[0005] Some aspects of the present disclosure relate to a method including obtaining a random delay for transmission of a radar pulse, and controlling a radar sensor to transmit the radar pulse at a point in time delayed by the random delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Some examples of apparatus and / or methods will be described below, by way of example only, and with reference to the accompanying drawings, in which:

[0007] Figure 1 An example of an apparatus for randomly delaying radar pulses is illustrated;

[0008] Figure 2a and Figure 2b An example of signal amplitude of a radar receive signal showing interference is illustrated;

[0009] Figure 3 illustrates an example of a radar system; and

[0010] Figure 4 An example of a method is illustrated. DETAILED DESCRIPTION

[0011] Some examples are now described in more detail with reference to the accompanying drawings. However, other possible examples are not limited to the features of these embodiments described in detail. Other examples may include modifications to features and equivalents and alternatives to features. In addition, the terms used to describe some examples herein should not limit other possible examples.

[0012] Throughout the description of the drawings, the same or similar reference numerals refer to the same or similar elements and / or features, which may be equivalent or implemented in a modified form while providing the same or similar functions. For clarity, the thickness of the lines, layers and / or regions in the drawings may also be exaggerated.

[0013] Unless explicitly defined otherwise in individual cases, when two elements A and B are combined using "or", this should be understood to disclose all possible combinations, i.e., only A, only B, and A and B. As alternative wording for the same combination, "at least one of A and B" or "A and / or B" can be used. This applies equally to combinations of more than two elements.

[0014] If singular forms such as "a", "an" and "the" are used, and there is no explicit or implicit definition that the use of only a single element is mandatory, other examples may also use several elements to implement the same functionality. If a function is described below as being implemented using multiple elements, other examples may use a single element or a single processing entity to implement the same functionality. It is further understood that the terms "include", "including", "comprise" and / or "comprising", when used, describe the presence of specified features, integers, steps, operations, processes, elements, components and / or groups thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, processes, elements, components and / or groups thereof.

[0015] Figure 1 An example of apparatus 100 coupled to radar sensor 110 is illustrated. For example, apparatus 100 may be located external to radar sensor 110 and communicatively coupled thereto. Figure 1 Alternatively to the example of , the apparatus 100 may be (eg, partially or completely) integrated into the radar sensor 110. The apparatus 100 may be such as described below with reference to Figure 3 The explained part of the radar system includes radar sensor 110 .

[0016] Device 100 includes circuit system 120 and optionally interface circuit system 130. In the case where interface circuit system 130 is present, interface circuit system 130 may be communicatively coupled (e.g., via a wired or wireless connection) to circuit system 120, such as for data or signal exchange between interface circuit system 130 and circuit system 120. Interface circuit system 130 may further be configured to establish a (e.g., wired or wireless) signal connection with radar sensor 110. In the case where circuit system 120 is integrated into radar sensor 110, device 100 may dispense with interface circuit system 130.

[0017] Interface circuitry 130 may be any device or component for communicating or exchanging data. For example, interface circuitry 130 may be a collection of electronic components, circuits, and / or subsystems for interacting between different interface entities (such as devices, systems, or components). Interface circuitry 130 may include voltage level shifters, buffers, amplifiers, filters, converters, multiplexers, demultiplexers, and / or various other electronic components.

[0018] Circuit system 120 is configured to obtain (e.g., determine and / or generate) a random delay for radar pulse transmission. As explained below, circuit system 120 may determine the random delay digitally and / or generate the random delay in an analog manner:

[0019] In the former case, the circuit system 120 may include a processing circuit system. The processing circuit system may be, for example, a single dedicated processor, a single shared processor, or multiple individual processors, digital signal processor (DSP) hardware, application specific integrated circuit (ASIC), microcontroller, or field programmable gate array (FPGA). The processing circuit system may optionally be coupled to, for example, a read-only memory (ROM), random access memory (RAM), and / or non-volatile memory for storing software.

[0020] The processing circuit system may use any technique to determine the random delay. For example, the processing circuit system may use a random value generator (such as at least one of a pseudo-random number generator, a hardware random number generator, etc.) to generate a (seemingly or truly) random number or value. A pseudo-random number generator may be a deterministic algorithm that uses a seed value as an input to generate a seemingly random number. The seed value may be based on a clock signal, etc. A hardware random number generator may generate random values ​​using an inherently random physical process (such as electronic noise or thermal noise).

[0021] Optionally or alternatively, the processing circuitry may receive random numbers from an external source (eg, via interface circuitry 130). Apparatus 100 may, for example, be coupled to an entropy source, a noise source, or a random value generator and receive random or seed values ​​therefrom.

[0022] The processing circuit system can determine the random delay based on the random value. To this end, the processing circuit system can perform further processing, such as scaling the random number into a predefined delay range. For example, the predefined delay range can be a pulse repetition interval of a radar pulse. Further processing can also include, for example, implementing restrictions on the random delay by modifying the random number so that a probability distribution predetermined for the random number is implemented. Optionally or alternatively, the predefined probability distribution can also be implemented by selecting a random value generator. For example, in some examples, the processing circuit system is configured to determine the random delay using a random value generator with a uniform probability distribution. The uniform probability distribution can ensure that each result (random delay value) has an equal chance of occurrence.

[0023] In the case of generating random delays in an analog manner, circuit system 120 may include random delay circuit system. Random delay circuit system may be any type of electronic circuit that is capable of randomly delaying a signal. For example, random delay circuit system may include an RC circuit coupled to a noise source, a delay line, etc. Circuit system 120 may include random delay circuit system and processing circuit system, for example, as explained above, the processing circuit system may control the random delay circuit system to generate a random delay having a predetermined characteristic.

[0024] The random delay may indicate a time relative to a reference time point, which is set, for example, by a clock signal of the radar sensor 110. The clock signal (clock pulse or clock cycle) may be a periodic electrical signal for coordinating the transmission of radar pulses by the radar sensor 110. It may serve as a timing reference for the sequential transmission of radar pulses. For example, the clock signal may assign a pulse repetition interval to each radar pulse by continuously setting the respective start (or end) of consecutive pulse repetition intervals. The clock signal may be generated by an oscillator of the radar sensor 110. For example, the radar sensor 110 may be a pulsed Doppler radar sensor (a Doppler radar sensor in pulse mode or a duty cycle Doppler radar sensor).

[0025] A pulse repetition interval (PRI) may refer to the duration of a radar pulse of a pulse train or sequence to be transmitted. The PRI may thus determine the timing and spacing between radar pulses. The PRI may include a duty cycle, during which a radar pulse is transmitted, and a pause or dwell time, during which radar sensor 110 remains silent, i.e., radar sensor 110 does not transmit any pulses at least until the start of the next pulse repetition interval.

[0026] For example, circuit system 120 may be configured to obtain a corresponding random delay for each radar pulse, for each radar pulse in a predefined number of radar pulses, for a frame of each radar pulse, or for each frame in a predefined number of frames. That is, for each radar pulse or set of radar pulses, a new random delay is obtained, which is (most likely) different from the previous random delay. The new generation of the random delay for each frame or set of frames will be further described below.

[0027] The circuit system 120 is further configured to control the radar sensor 110 to transmit a radar pulse at a time point delayed by the random delay. For example, the device 100 may transmit the random delay to the radar sensor 110 (e.g., via the interface circuit system 130) to trigger the transmission of the radar pulse based on the random delay. In the case where the circuit system 120 determines the random delay digitally, the processing circuit system of the circuit system 120 may be configured to control the delay circuit system of the radar sensor 110 to delay the transmission of the radar pulse by a duration corresponding to the random delay. The delay circuit system of the radar sensor 110 may be coupled to an oscillator and delay the clock signal by the random delay. Alternatively, the circuit system 120 may transmit the random delay to the antenna control circuit system of the radar sensor 110, and the antenna control circuit system sets the transmission time of the radar pulse at the antenna of the radar sensor 110 according to the random delay. In the case where the circuit system 120 generates the random delay in an analog manner, the circuit system 120 may be coupled to the oscillator and / or the antenna and perform the delay itself.

[0028] By randomly delaying the transmission time of the radar pulses, interference between the radar sensor 110 and a different second radar sensor (same or different type) operating at the same or similar radio frequency in the vicinity of the radar sensor 100 can be mitigated. Since the radiation of the second radar sensor may be mistaken as an echo of the radar pulse of the radar sensor 110, the interference may lead to false target or false triggering of motion detection when analyzing the radar signal. In some cases, such as when the radar sensors are close to each other, the interference may be so strong that during the interference period, the radar sensor 110 is "blind", that is, valid targets or target motion that may be farther away than the second radar sensor cannot be detected because the target (motion) signature in the recorded echo data is "covered" (superimposed) by the interference signature. Examples of interference are Figure 2a and Figure 2b shown.

[0029] Figure 2a and Figure 2bGraph 200 showing the amplitude 210 of I samples and Q samples of a radar receive signal (here: intermediate frequency signal) generated by a radar sensor at two different time scales (at time intervals of 180 minutes and 6 seconds, respectively). A radar sensor (“victim”) is placed near a second radar sensor (“aggressor”) operating at substantially the same radio frequency (e.g., in the frequency range of 24.0 to 24.25 GHz). The radar sensor transmits a radar pulse and then receives a radar signal, which is perceived as an echo of the radar pulse reflected from an object in its field of view. The radar sensor then generates a radar receive signal by IQ sampling the received radar signal, producing Figure 2a and Figure 2b Figure 200.

[0030] The impact of interference can alternatively be measured in a configuration in which the victim's receive antenna and the aggressor's transmit antenna are coupled via an RF cable and an optional attenuator. In a free-field measurement, the characteristics of the cable (e.g., cable loss) and the attenuator may correspond to a certain distance between the victim and the aggressor. In a specific interference scenario, the impedance of the radar sensor may be 50 ohms, the transmit power of the transmit antenna may be 0 dBm, and the antenna gain of the transmit and receive antennas may be 10 dB. In a free field of 50 cm to 1 meter, the estimated receive antenna power may be -34 dBm to 40 dBm provided via the attenuator and cable.

[0031] exist Figure 2a and Figure 2b In the example of , the radar sensor and the second radar sensor can be Doppler radar sensors operating in pulse mode (pulse Doppler radar sensor, duty cycle Doppler radar sensor). The pulse mode operation of the radar sensor involves transmitting bursts or pulses of radio waves (radar pulses) with a duration of, for example, microseconds. That is, neither radar sensor continuously transmits radar signals. The pulse mode can be implemented to save computing and energy resources. It should be noted that the technology described herein is not limited to a certain type of radar sensor, nor is it limited to scenarios where the victim and the attacker are of the same type. For example, at least one of the radar sensors can be a frequency modulated radar sensor.

[0032] The radar sensor may be operated with a pulse repetition interval having a predefined duration (e.g. 1 millisecond) and with a predefined pulse width of the radar pulse (e.g. 1 microsecond). The victim and the aggressor may determine the timing of their transmissions based on a clock signal generated using an oscillator. For example, in the case of two similar clock sources, the clocks of the radar sensor may be similar. For example, both the victim and the aggressor may include respective crystal oscillators with a frequency of, for example, 38,4 MHz. Due to the non-ideality of the clock sources, the timing of the clock sources may slowly deviate (drift) away from each other or shift (drift) towards each other.

[0033] Figure 2a It is shown that at regular time intervals, the amplitude 210 exhibits peak values. Figure 2a In the example of , the time interval between two subsequent peaks is 51 minutes of duration 220, resulting in a pulse repetition interval match of 0.3 parts per million. These peaks indicate interference between the victim and the attacker, that is, the time at which the attacker's radiation coincides with the time at which the victim "listens" to the echo of its radar pulse. The regular nature of this occurrence is due to a relatively stable mismatch between the oscillators, resulting in the time difference between the victim's pulse and the attacker's pulse gradually adding up until the complete pulse repetition interval is crossed, so that the clocks are regularly matched and separated. However, it should be noted that the technology described herein is not limited to such regular interference. It is equally applicable to scenarios where interference occurs irregularly.

[0034] Figure 2b Shows Figure 2a 210. Specifically, it shows Figure 2a The amplitude 210 is shown for the time between the 6740th second and the 6746th second. Figure 2b Provides zoom to Figure 2a A view of one of the peaks shown.

[0035] Figure 2b The disturbing values ​​of amplitude 210 shown in FIG. 2 and the resulting high values ​​thereof last for a duration 230 of approximately 5 seconds, primarily for a duration 240 of approximately 3 seconds.

[0036] Figure 2a and Figure 2b The measurements shown in can be cross-checked by calculating the interference period. Assuming the interference frequency between the attacker and the victim is 1 every 51 minutes (3060 seconds), the oscillator matching can be approximated based on the following equation 1:

[0037] Oscillator Match = 1-(((T IPP ) / (T PRT )) / ((T IPP ) / (TPRT )+1))=0.327 parts per million Equation 1, where T IPP is the interference period (here 3060 seconds), T PRT is the duration of the pulse repetition interval (here 1 ms).

[0038] The jammer duration for a pulse width TPW of 1 microsecond can be approximated based on the following equation 2:

[0039] Main interference duration = (TPW) / (oscillator matching) = 3.06 seconds Equation 2.

[0040] Mathematics Cross Check and Figure 2a and Figure 2b The measurements shown fit well, where the interference duration is about 3 seconds. It can be assumed that as the clock frequency approaches, both the interference duration and the non-interference duration become longer.

[0041] Figure 2a and Figure 2b The illustrated scenario shows that interference may typically affect the radar sensor for a very long duration, wherein substantially all samples are affected. Conventional interference cancellation may therefore be impractical, as the affected radar sensor may be blind for too long a period of time, i.e., if the interference time is cut off from the received radar signal, the radar sensor will not be able to detect any real targets for an unduly long time.

[0042] As described herein, random delays in the transmit times of radar pulses can prevent such long jamming periods and / or frequent occurrences of jamming because it can statistically establish asynchrony between the transmit timing of the victim and the transmit timing of the aggressor. Jamming can therefore occur more rarely and / or for shorter periods of time.

[0043] Return to reference Figure 1 , the random delay may be constrained by apparatus 100 such that the random delay is different in duration from the pulse repetition interval of the radar pulse and multiples thereof. That is, the random delay may cause the start of the radar pulse to drift within its original or subsequent pulse repetition interval, e.g., to be offset relative to the start of the pulse repetition interval. Since the transmit timing of the second radar sensor is assumed to remain constant or likewise randomly adjusted, a radar pulse transmitted by radar sensor 110 or its echo will be less likely to coincide with a radar signal of the second radar sensor.

[0044] In some examples, the random delay may be less than the duration of a pulse repetition interval of the radar pulse or less than the duration of the dwell time. For example, the random delay may be constrained by circuit system 120 so that no pulse repetition interval is omitted, but the transmission is shifted within the pulse repetition interval of the radar pulse. For example, the start of the transmission of the radar pulse may be initially set to the start of the PRI, and the random delay causes the transmission to be postponed within the PRI.

[0045] According to a specific delay mechanism, the delay may have a certain granularity, that is, only discrete delay values ​​may be randomly selected. The smaller the granularity (delay pattern), the less likely interference is. For example, for a pulse width of 1 microsecond and a PRT duration of 10 milliseconds, a granularity of 2 microseconds may mean a 1 / 5000 probability of interference (when radar sensor 110 and the second radar sensor use similar oscillators). For example, according to the granularity, the random delay may have any value or duration. For example, the duration may be at least one microsecond or a multiple thereof. In some examples, the duration of the random delay may be greater than the pulse width of the radar pulse. The latter may prevent the radar pulse from being shifted too small to leave the interference window.

[0046] For any subsequent radar pulse, the random delay can be re-determined: circuit system 120 can be further configured to obtain a second (different) random delay for the transmission of a second radar pulse and control radar sensor 110 to transmit the second radar pulse at a time point delayed by the second random delay. In this way, the random transmission of radar pulses can be continued to prevent interference.

[0047] In some cases, the random delay can be maintained within the radar pulse frame and recalculated for subsequent radar pulse frames. For example, the circuit system 120 can be configured to control the radar sensor so that it starts transmitting a frame of multiple radar pulses at a time point delayed by the random delay. The frame may include a pulse that causes an echo, and the echo will be processed together, for example, for estimating the speed or existence of a moving target. Each radar pulse of a frame (or a set of frames) can be shifted with the same delay, but the delay may change between a frame (or a set of frames) and a frame (or a subsequent set of frames). This can simplify signal processing and filtering of the generated radar data. For example, the echoes of the radar pulses of a frame can be more easily coherently superimposed. The circuit system 120 can be configured to control the radar sensor so that it starts transmitting a second frame of multiple radar pulses at a time point delayed by a second random delay. The device 100 can therefore enable the random frame start delay for processing the self-interference of two radar sensors (e.g., two pulsed Doppler radar sensors). In the case of multiple frames, circuit system 120 can be configured to obtain a corresponding random delay for transmission of each of the multiple frames of the multiple radar pulses, and control radar sensor 110 to transmit each of the multiple frames based on the corresponding random delay. That is, the random delay can be re-determined for each frame.

[0048] The device 100 can thus reduce the probability that two or more consecutive frames are disturbed to avoid longer interference periods (during which the radar sensor 110 is blind). By re-determining the random delay for each frame, asynchrony can be established between the radar sensors from frame to frame. Interferences may occur more frequently or more rarely because their occurrence depends on randomness and not only on oscillator mismatches of the radar sensors. However, it is highly unlikely that interference lasts for several frames in a row.

[0049] The device 100 may further perform processing of the radar data after the radar pulses are randomly transmitted. For example, the device 100 may further include a processing circuit system, or in the case where the circuit system 120 includes a processing circuit system, the additional processing circuit system may be exempted. The processing circuit system may be configured to obtain radar data indicating the echo of the transmitted radar pulse and detect at least one of the presence and movement of the target based on the radar data. The device 100 can therefore be effectively reused for data processing. For example, the processing circuit system may be configured to detect at least one of the presence and movement of the target by determining the number of zero crossings in the radar data. Since the number of zero crossings indicates the spectral characteristics of the radar data, their analysis can be used to detect the target, for example, by thresholding the rate or number of zero crossings.

[0050] In order to further prevent false targets due to interference, a sliding window can be optionally used. The processing circuit system can therefore be configured to detect at least one of the presence and motion of the target by applying a sliding window on the radar data. For example, if a predefined number of continuous frames of radar data indicates at least one of the presence and motion of the target, the processing circuit system can be configured to detect at least one of the presence and motion of the target. Optionally or alternatively, if at least a predefined number of frames from other predefined numbers of continuous frames indicate at least one of the presence and motion of the target, that is, if the ratio of the target indication frame to the non-target indication frame exceeds a certain threshold, the processing circuit system can be configured to detect at least one of the presence and motion of the target. Therefore, frame-based motion detection can therefore be implemented: for example, multiple (e.g., 2 or 3) frames in a row can be searched for a target, and only if at least a predefined number of multiple frames indicate a target or if at least x≥1 frame in y≥2 frames indicates a target, it is assumed that the target is detected. The sliding window may be implemented by collecting interim or preliminary detection outputs for several frames and setting a final or updated detection output for the several frames.

[0051] The detection of a target (motion or presence) can be used to wake up the external microcontroller: the processing circuit system can be further configured to: if at least one of the presence and motion of a target is detected, wake up the external processing circuit system to further process the radar data. For example, the external processing circuit system can specifically process frames in which targets are detected. Further processing may include more complex operations, such as target tracking, determination of speed, range or angle of the target, etc. Therefore, the device 100 can offload the (main) processor from computationally intensive operations by sorting out irrelevant frames (frames without targets).

[0052] Figure 3 An example of a radar system 300 is illustrated. The radar system 300 includes an apparatus 310 described herein, such as the apparatus 100, and a radar sensor 320. The radar sensor 320 includes at least one antenna 322 configured to transmit radar pulses at delayed points in time.

[0053] Despite Figure 3 Device 310 and radar sensor 320 are depicted as separate blocks, but in other examples, device 310 may be partially or fully included in radar sensor 320, thereby correspondingly including all or a portion of circuitry 120 (eg, processing circuitry) of device 310.

[0054] In the case where the device 310 is only partially included in the radar sensor 320, the radar system 300 may include a distributed processing circuit system, which is, for example, in the form of a first processing (sub-)circuit system included in the radar sensor 320, and a second processing (sub-)circuit system located outside the sensor and communicating with the first processing circuit system by means of an interface circuit system (e.g., the interface circuit system 130), performing corresponding parts of the processing steps, for example, for exchanging data between the first processing circuit system and the second processing circuit system.

[0055] In the case where apparatus 310 is integrated in radar sensor 320 , processing circuitry and radar sensor 320 may be integrated together in a single semiconductor chip, or in more than one semiconductor chip.

[0056] In the event that device 310 is not included in radar sensor 320 , the circuitry may take the form of circuitry external to radar sensor 320 and may be communicatively coupled to radar sensor 320 via interface circuitry.

[0057] The radar sensor 320 further includes an optional crystal oscillator 324, which is configured to output a clock signal. The pulse repetition interval of the radar pulse is based on the clock signal. That is, the clock signal can provide timing for the pulse repetition interval. For example, the start of the pulse repetition interval can be set by counting a predefined number of pulses (e.g., a falling edge or a rising edge) of the clock signal. The crystal oscillator 324 can therefore be coupled to the antenna 322, for example, to an antenna control circuit, etc.

[0058] In some examples, radar sensor 320 may further include a delay circuit system coupled to crystal oscillator 324 (e.g., between crystal oscillator 324 and antenna 322). The delay circuit system is configured to generate a random delay. As described above, in the case where the random delay is generated by device 310 or the random delay is fully implemented digitally, radar sensor 320 (or even the entire radar system 300) can be exempted from the (analog) delay circuit system.

[0059] For example, the radar sensor 320 may be a Doppler radar sensor in pulse mode (pulsed Doppler radar sensor, duty cycle Doppler radar sensor). That is, the radar sensor 320 may be a Doppler radar sensor (e.g., emitting radiation of a single frequency essentially), which is not continuously on, but emits short "pulses" when samples are needed to save power. The radar sensor 320 may therefore be duty cycled, i.e., having a duty cycle (ratio between pulse duration or pulse width and period or pulse repetition interval) less than 1. In such a radar sensor, (short duration) radar pulses are emitted, for example, in bursts or packets. These radar pulses are reflected by objects in the radar field of view, including stationary and moving targets. The radar sensor 320 then receives the reflected signal (echo), and based on the received echo, generates a radar receive signal (e.g., an intermediate frequency signal). By analyzing the Doppler shift of the return signal, the speed of the target relative to the radar sensor 320 can be determined. For example, the radar system 300 can determine the presence of a person based on the velocity signature in the radar receive signal.

[0060] For more details and aspects of radar system 300, see for example Figure 1 , explained in conjunction with the proposed technology or one or more examples described above. The radar system 300 may include one or more additional optional features, which correspond to one or more aspects of the proposed technology or one or more examples described above.

[0061] Figure 4 An example of a method 400 is illustrated. The method 400 may be performed by an apparatus described herein, such as the apparatus 100.

[0062] The method 400 includes obtaining 410 a random delay for radar pulse transmission and controlling 420 a radar sensor to transmit a radar pulse at a point in time delayed by the random delay.

[0063] For more details and aspects of method 400, see for example Figure 1 , explained in conjunction with the proposed technology or one or more examples described above. The method 400 may include one or more additional optional features, which correspond to one or more aspects of the proposed technology or one or more examples described above.

[0064] In the following, some examples of the proposed technique are presented:

[0065] An example (eg, Example 1) relates to an apparatus including a circuit system configured to obtain a random delay for transmission of a radar pulse, and to control a radar sensor to transmit the radar pulse at a time point delayed by the random delay.

[0066] Another example (eg, Example 2) relates to the previous example (eg, Example 1) or any other example, further comprising: the random delay is different from the duration of the pulse repetition interval of the radar pulse and its multiples.

[0067] Another example (eg, Example 3) relates to the previous example (eg, one of Examples 1 or 2) or any other example, further comprising: the random delay is less than the duration of the pulse repetition interval of the radar pulse.

[0068] Another example (e.g., Example 4) relates to a previous example (e.g., one of Examples 1 to 3) or any other example, further including: the circuit system is configured to control the radar sensor to start transmitting a frame of multiple radar pulses at a time point delayed by a random delay.

[0069] Another example (e.g., Example 5) relates to the previous example (e.g., one of Examples 1 to 4) or any other example, further including: the circuit system is further configured to obtain a different second random delay for transmission of a second radar pulse, and control the radar sensor to transmit the second radar pulse at a time point delayed by the second random delay.

[0070] Another example (eg, Example 6) relates to the previous examples (eg, Examples 4 and 5), wherein the circuit system is configured to control the radar sensor to start transmitting a second frame of the plurality of radar pulses at a time point delayed by a second random delay.

[0071] Another example (e.g., Example 7) relates to a previous example (e.g., one of Examples 1 to 6) or any other example, further including: the circuit system is configured to obtain a corresponding random delay for transmission of each of a plurality of frames of a plurality of radar pulses, and control the radar sensor to transmit each of the plurality of frames based on the corresponding random delay.

[0072] Another example (e.g., Example 8) relates to a previous example (e.g., one of Examples 1 to 7) or any other example, further including a processing circuit system configured to obtain radar data indicating an echo of the transmitted radar pulse and detect at least one of the presence and movement of a target based on the radar data.

[0073] Another example (e.g., Example 9) relates to the previous example (e.g., Example 8) or any other example, further including: if a predefined number of consecutive frames of radar data indicate at least one of the presence and movement of a target, the processing circuit system is configured to detect at least one of the presence and movement of the target.

[0074] Another example (e.g., Example 10) relates to the previous example (e.g., Example 8) or any other example, further including: if at least a predefined number of frames from another predefined number of consecutive frames indicate at least one of the presence and movement of the target, the processing circuit system is configured to detect at least one of the presence and movement of the target.

[0075] Another example (e.g., Example 11) relates to a previous example (e.g., one of Examples 8 to 10) or any other example, further including: the processing circuit system is configured to detect at least one of the presence and movement of a target by applying a sliding window on the radar data.

[0076] Another example (e.g., Example 12) relates to a previous example (e.g., one of Examples 8 to 11) or any other example, further including: the processing circuit system is further configured to wake up the external processing circuit system to further process the radar data if at least one of the presence and motion of a target is detected.

[0077] Another example (e.g., Example 13) relates to a previous example (e.g., one of Examples 8 to 12) or any other example, further including: the processing circuit system is configured to detect at least one of the presence and movement of a target by determining the number of zero crossings in the radar data.

[0078] Another example (e.g., Example 14) relates to the previous example (e.g., one of Examples 1 to 13) or any other example, further including: the circuit system is configured to determine the random delay using a random value generator with a uniform probability distribution.

[0079] Another example (eg, Example 15) relates to the previous example (eg, one of Examples 1 to 14) or any other example, further comprising: the random delay having a duration of at least one microsecond or a multiple thereof.

[0080] Another example (eg, Example 16) relates to a previous example (eg, one of Examples 1 to 15) or any other example, further comprising: a duration of the random delay is greater than a pulse width of the radar pulse.

[0081] One example (eg, Example 17) relates to a radar system comprising the apparatus of the previous example and a radar sensor, wherein the radar sensor comprises at least one antenna configured to transmit radar pulses at delayed points in time.

[0082] Another example (e.g., Example 18) relates to the previous example (e.g., Example 17) or any other example, further including: the radar sensor includes a crystal oscillator configured to output a clock signal, and wherein the pulse repetition interval of the radar pulse is based on the clock signal.

[0083] Another example (e.g., Example 19) relates to the previous example (e.g., Example 18) or any other example, further including: the radar sensor includes a delay circuit system, the delay circuit system is coupled to the crystal oscillator and is configured to generate a random delay.

[0084] Another example (e.g., Example 20) relates to the previous example (e.g., one of Examples 17 to 19) or any other example, further including: the radar sensor is a pulsed Doppler radar sensor.

[0085] One example (eg, Example 21) relates to a method, the method comprising: obtaining a random delay for transmission of a radar pulse, and controlling a radar sensor to transmit the radar pulse at a time point delayed by the random delay.

[0086] Another example (eg, Example 22) involves a non-transitory machine-readable medium having a program stored thereon, the program having program code for performing the method of Example 21 when the program is executed on a processor or programmable hardware.

[0087] Another example (eg, Example 23) relates to a program having a program code for executing the method of Example 21 when the program is executed on a processor or programmable hardware.

[0088] The aspects and features described with respect to a specific example in the foregoing examples may also be combined with one or more other examples to replace equivalent or similar features of the other examples, or to additionally introduce these features into the other examples.

[0089] The example may further be or relate to a (computer) program including a program code, and the program code is used to perform one or more of the above methods when the program is executed on a computer, a processor or other programmable hardware component. Therefore, the steps, operations or processes of the different methods in the above method can also be performed by a programmed computer, a processor or other programmable hardware component. The example can also cover a program storage device (such as a digital data storage medium), which is readable by a machine, a processor or a computer, and encodes and / or contains machine-executable, processor-executable or computer-executable programs and instructions. For example, the program storage device may include or may be a digital storage device, a magnetic storage medium (such as a disk and a tape), a hard drive or an optically readable digital data storage medium. Other examples may also include a computer, a processor, a control unit, a (field) programmable logic array ((F)PLA)), a (field) programmable gate array ((F)PGA), a graphics processor unit (GPU), an application-specific integrated circuit (ASIC), an integrated circuit (IC) or a system on a chip (SoC) system programmed to perform the steps of the above method.

[0090] It is further understood that, unless expressly stated in individual cases or necessary for technical reasons, the disclosure of several steps, processes, operations or functions disclosed in the specification or claims should not be interpreted as implying that these operations must depend on the described order. Therefore, the foregoing description does not limit the execution of several steps or functions to a certain order. In addition, in other examples, a single step, function, process or operation may include and / or be decomposed into several sub-steps, sub-functions, sub-processes or sub-operations.

[0091] If certain aspects have been described with respect to a device or system, these aspects should also be understood as descriptions of the corresponding methods. For example, blocks, devices, or functional aspects of a device or system may correspond to features of a corresponding method, such as method steps. Therefore, aspects described with respect to a method should also be understood as descriptions of corresponding blocks, corresponding elements, attributes, or functional features of the corresponding device or system.

[0092] The following claims are hereby incorporated into the detailed description, where each claim may stand on its own as a separate example. It should also be noted that, although in the claims, a dependent claim refers to a specific combination with one or more other claims, other examples may also include a combination of a dependent claim with the subject matter of any other dependent or independent claim. Unless it is stated in individual cases that a specific combination is not intended, such a combination is hereby expressly proposed. In addition, features of a claim shall also be included with respect to any other independent claim, even if the claim is not directly defined as dependent on the other independent claim.

Claims

1. A device (100), comprising a circuit system (120), wherein the circuit system is configured to: obtaining a random delay for transmission of radar pulses; and The radar sensor (110) is controlled to transmit the radar pulse at a time point delayed by the random delay.

2. The apparatus (100) of claim 1, wherein the random delay is less than the duration of a pulse repetition interval of the radar pulse.

3. The apparatus (100) of any one of the preceding claims, wherein the circuit system (120) is configured to control the radar sensor (110) to start transmitting a frame of multiple radar pulses at a time point delayed by the random delay.

4. The apparatus (100) of any one of the preceding claims, wherein the circuit system (120) is further configured to: obtaining a different second random delay for transmission of a second radar pulse; and The radar sensor (110) is controlled to transmit the second radar pulse at a time point delayed by the second random delay.

5. The apparatus (100) according to claim 3 and 4, wherein the circuit system (120) is configured to control the radar sensor (110) to start transmitting a second frame of multiple radar pulses at a time point delayed by the second random delay.

6. The apparatus (100) of any one of the preceding claims, wherein the circuit system (120) is configured to: for each of a plurality of frames of a plurality of radar pulses, obtaining a respective random delay for transmitting the frame; and The radar sensor (110) is controlled to transmit each of the plurality of frames based on the corresponding random delay.

7. The apparatus (100) of any preceding claim, further comprising a processing circuit system (120), the processing circuit system (120) being configured to: obtaining radar data indicative of returns of the transmitted radar pulses; and Based on the radar data, at least one of presence and motion of a target is detected.

8. The apparatus (100) of claim 7, wherein the processing circuit system (120) is configured to detect at least one of the presence and motion of the target if a predefined number of consecutive frames of the radar data indicate at least one of the presence and motion of the target.

9. An apparatus (100) according to claim 7, wherein the processing circuit system (120) is configured to detect at least one of the presence and movement of the target if at least a predefined number of frames from another predefined number of consecutive frames indicate at least one of the presence and movement of the target.

10. The apparatus (100) of any preceding claim, wherein the circuitry (120) is configured to determine the random delay using a random value generator having a uniform probability distribution.

11. A radar system (300), comprising: The device (310) according to any of the preceding claims; as well as A radar sensor (320) is provided, wherein the radar sensor (320) comprises at least one antenna (322) configured to transmit radar pulses at delayed points in time.

12. The radar system (300) of claim 11, wherein the radar sensor (320) comprises a crystal oscillator (324) configured to output a clock signal, and wherein a pulse repetition interval of the radar pulses is based on the clock signal.

13. The radar system (300) of claim 12, wherein the radar sensor (320) includes delay circuitry coupled to the crystal oscillator (324) and configured to generate the random delay.

14. The radar system (300) according to any one of claims 11 to 13, wherein the radar sensor (320) is a pulsed Doppler radar sensor (320).

15. A method (400), comprising: obtaining (410) a random delay for transmission of a radar pulse; as well as The radar sensor is controlled (420) to transmit the radar pulse at a time point delayed by the random delay.

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