Transmit alignment and interference reduction for FMCW radar systems to analyze frequency differences between transmit CHIPR

Abstract

The present invention relates to a first radar device (100) which aligns its emission with the emission of a second radar device (300), thereby expanding the coverage of object detection and improving the resolution of object detection. The first radar device (100) aligns its emission with the emission of a second radar signal (520) from the second radar device (300) by determining a predetermined emission delay with respect to the second radar signal (520) based on the received radar signal. The first radar device (100) then aligns its emission with the emission of the second radar signal (520) by tracking the second radar signal (520) with the predetermined emission delay. Therefore, the positioning performance of the target object can be improved. The invention also relates to a control device (540) for determining the position of the object (700) on the basis of the positioning signals (550, 560) from the aligned first and second radar devices (100, 300). The invention further relates to a corresponding method and to a computer program.

Description

Technical Field

[0001] Embodiments of the invention relate to a first radar device for aligning its transmissions with those of a second radar device. Furthermore, the invention also relates to a corresponding method and a computer program. Background Art

[0002] Indoor radar and high-resolution human detection in home or work environments are very important for different application scenarios, such as: health monitoring in elderly homes, safety in industrial hazardous areas, VR sports, crowd control in airports / cinemas, etc. Due to multipath propagation and the diverse layout of indoor scenes, it is difficult for a single radar to fully cover the indoor environment. A single radar setup is limited by its setup location, room layout, and relative position to human targets. Highly undesirable multipath propagation may occur, reducing the sensitivity of a single radar setup. Summary of the invention

[0003] An object of embodiments of the present invention is to provide a solution that alleviates or solves the disadvantages and problems of conventional solutions.

[0004] Another object of an embodiment of the present invention is to provide a solution for aligning the transmissions of multiple radar devices, thereby expanding the coverage range of the radar system and improving the resolution of the radar system.

[0005] The above and other objects are achieved by the subject matter claimed in the independent claims. Further embodiments of the invention are provided in the dependent claims.

[0006] According to a first aspect of the present invention, the above and other objects are achieved by a first radar device for a radar system, the first radar device being configured to:

[0007] transmitting a first radar signal comprising a time-varying frequency signal;

[0008] receiving a second radar signal from a second radar device during transmission of the first radar signal, the second radar signal comprising the time-varying frequency signal;

[0009] detecting a pilot from the second radar signal;

[0010] determining a predetermined transmission delay of the first radar signal relative to the second radar signal based on an echo signal of the first radar signal and the detected pilot;

[0011] The transmission of the first radar signal is aligned with the transmission of the second radar signal by tracking the second radar signal with the predetermined transmission time delay.

[0012] An advantage of the first radar device according to the first aspect is that by aligning the transmission of the first radar signal with the transmission of the second radar signal, the transmission of the first radar device will be synchronized with the transmission of the second radar device. Therefore, the first radar device can detect echoes of the second radar transmission from the second radar device. Compared with the echoes of the second radar transmission received from the second radar device, these echoes detected by the first radar device have traveled a different path. By estimating echoes emitted by the same radar from different paths, the localization performance of the target object can be improved.

[0013] In an implementation manner of the first radar device according to the first aspect, the time-varying frequency signal is a Compressed High Intensity Radar Pulse (CHIRP) signal.

[0014] In an implementation manner of the first radar device according to the first aspect, the CHIRP signal is an uplink CHIRP signal.

[0015] In an implementation manner of the first radar device according to the first aspect, the second radar signal is a line-of-sight signal from the second radar device.

[0016] Thus, the first radar device may more easily track the transmissions of the second radar device because the first radar device may use the line-of-sight signal to track the transmissions of the second radar device.

[0017] In an implementation manner of the first radar device according to the first aspect, tracking the second radar signal includes:

[0018] A transmit frequency of the first radar device is adjusted based on the detected pilot.

[0019] The advantage of this implementation is that by adjusting the transmit frequency of the first radar device, the transmit frequency of the first radar device will be synchronized with the transmit frequency of the second radar device. Therefore, the echoes that are the result of the second radar transmission can be detected by the first radar device. Therefore, these echoes have traveled a different path than the echoes received by the second radar device. Therefore, by estimating echoes from different paths, better positioning performance can be obtained.

[0020] In an implementation manner of the first radar device according to the first aspect, adjusting the transmission frequency of the first radar device includes:

[0021] adjusting a reference frequency to the detected pilot frequency;

[0022] The transmit frequency of the first radar device is adjusted based on the adjusted reference frequency.

[0023] In an implementation manner of the first radar device according to the first aspect, the transmission frequency of the first radar device is equal to the adjusted reference frequency multiplied by N / M, where N and M are adjustable positive integers.

[0024] In an implementation manner of the first radar device according to the first aspect, the detected pilot frequency is equal to a frequency difference between the transmit frequency of the first radar device and the transmit frequency of the second radar device.

[0025] The advantage of this implementation is that the first radar device can follow the frequency and phase of the second radar signal transmitted by the second radar device. This synchronization does not require a physical connection for reference / control signaling between the first radar device and the second radar device. Therefore, the deployment and implementation complexity in the radar system is reduced.

[0026] In an implementation manner of the first radar device according to the first aspect, the first radar device is further configured to:

[0027] receiving a trigger signal from a trigger network;

[0028] The first radar signal is transmitted based on the received trigger signal.

[0029] An advantage of this implementation is that the timing accuracy between the first radar device and the second radar device may be improved by using a common trigger network.

[0030] In an implementation manner of the first radar device according to the first aspect, the first radar device is further configured to:

[0031] determining a trigger signal based on the detected pilot;

[0032] The first radar signal is transmitted based on the determined trigger signal.

[0033] The advantage of this implementation is that by using pilot detection to determine the trigger signal, no common trigger network is required, thus further reducing the deployment and implementation complexity of the radar system.

[0034] According to a second aspect of the present invention, the above and other objects are achieved by a control device for a radar system, the radar system comprising a first radar device and a second radar device according to the first aspect; the control device is used to:

[0035] receiving a first positioning signal from the first radar device, the first positioning signal indicating a first position of an object;

[0036] receiving a second positioning signal from the second radar device, the second positioning signal indicating a second position of the object;

[0037] A final position of the object is determined based on the first position of the object and the second position of the object.

[0038] An advantage of the control device according to the second aspect is that by combining multiple positioning signals from different radar devices according to an embodiment of the present invention, the positioning accuracy of the target object can be further improved.

[0039] In an implementation manner of the control device according to the second aspect, the first radar device and the second radar device are within line of sight of each other.

[0040] Thus, the first radar device may more easily track the transmissions of the second radar device because the first radar device may use the line-of-sight signal to track the transmissions of the second radar device.

[0041] In an implementation of the control device according to the second aspect, the first radar device is used to transmit a first radar signal including a time-varying frequency signal, and the second radar device is used to transmit a second radar signal including the time-varying frequency signal, and wherein the first radar signal is transmitted with a predetermined transmission delay relative to the second radar signal.

[0042] According to a third aspect of the present invention, the above and other objects are achieved by a method for a first radar device, the method comprising:

[0043] transmitting a first radar signal comprising a time-varying frequency signal;

[0044] receiving a second radar signal from a second radar device during said transmitting of said first radar signal, said second radar signal comprising said time-varying frequency signal;

[0045] detecting a pilot from the second radar signal;

[0046] determining a predetermined transmission delay of the first radar signal relative to the second radar signal based on an echo signal of the first radar signal and the detected pilot;

[0047] The transmission of the first radar signal is aligned with the transmission of the second radar signal by tracking the second radar signal with the predetermined transmission time delay.

[0048] The method according to the third aspect can be extended to an implementation corresponding to the implementation of the first radar device according to the first aspect. Therefore, an implementation of the method comprises one or more features of the corresponding implementation of the first radar device.

[0049] The advantages of the method according to the third aspect are the same as the advantages of the corresponding implementation of the first radar device according to the first aspect.

[0050] According to a fourth aspect of the present invention, the above and other objects are achieved by a method for a control device of a radar system, the radar system comprising a first radar device and a second radar device according to the first aspect, the method comprising:

[0051] receiving a first positioning signal from the first radar device, the first positioning signal indicating a first position of an object;

[0052] receiving a second positioning signal from the second radar device, the second positioning signal indicating a second position of the object;

[0053] A final position of the object is determined based on the first position of the object and the second position of the object.

[0054] The method according to the fourth aspect can be extended to an implementation corresponding to the implementation of the control device according to the second aspect. Therefore, an implementation of the method includes one or more features of the corresponding implementation of the control device.

[0055] The advantages of the method according to the fourth aspect are the same as the advantages of the corresponding implementation of the control device according to the second aspect.

[0056] An embodiment of the present invention further relates to a computer program, characterized by a program code, when the program code is executed by at least one processor, the program code causes the at least one processor to perform any one of the methods provided according to the embodiments of the present invention. In addition, an embodiment of the present invention further relates to a computer program product comprising a computer-readable medium and the computer program, wherein the computer program is included in the computer-readable medium and may include one or more of the following groups: read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), flash memory, electrically erasable PROM (EEPROM), hard disk drive, etc.

[0057] Other applications and advantages of embodiments of the present invention will be apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The accompanying drawings are intended to illustrate and explain different embodiments of the present invention, in which:

[0059] Figure 1 A first radar device according to an embodiment of the present invention is shown;

[0060] Figure 2 shows a timing diagram of a first radar signal and a second radar signal according to an embodiment of the present invention;

[0061] Figure 3 A coordinate diagram showing a pilot according to an embodiment of the present invention;

[0062] Figure 4 A flow chart showing a method for a first radar device according to an embodiment of the present invention is shown;

[0063] Figure 5 shows the triggering of a first radar device according to an embodiment of the present invention;

[0064] Figure 6 shows functional blocks of a first radar device according to an embodiment of the present invention;

[0065] Figure 7 A digital signal processor of a first radar device according to an embodiment of the present invention is shown;

[0066] Figure 8 A control device for a radar system according to an embodiment of the present invention is shown;

[0067] Fig. 9 shows a detection area for a radar system according to an embodiment of the present invention;

[0068] Fig.10 A flow chart of a method for controlling a device according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0069] The coverage of indoor radars can be expanded by using multiple radars. However, if multiple radars are not synchronized, the use of these radars will also cause interference between radars. In traditional solutions, it has been proposed to use multiple radars simultaneously to enhance indoor detection capabilities. Traditional solutions mainly rely on cables and / or Ethernet connections for inter-system communication. Due to quality issues of such connections, radars are not easy to synchronize unless optical fiber is used for inter-system communication. Optical fiber is expensive and difficult to deploy in practice. Therefore, according to an embodiment of the present invention, a solution for achieving radar synchronization based on a wireless interface is proposed, which provides a first radio device that can be aligned with a second radar device for transmission.

[0070] Figure 1 A first radar device 100 for use in a radar system 500 according to an embodiment of the present invention is shown. The first radar device 100 is used to align its transmission with the transmission of a second radar device 300 in the radar system 500. Therefore, the first radar device 100 may be referred to as a slave radar or slave, and the second radar device 300 may be referred to as a master radar or master.

[0071] refer to Figure 1 and Figure 2 , the first radar device 100 is used to transmit a first radar signal 510 including a time-varying frequency signal, which time-varying frequency signal can be understood as a radar signal having a frequency that varies with time. During the transmission of the first radar signal 510, the first radar device 100 receives a second radar signal 520 from the second radar device 300. The second radar signal 520 includes a time-varying frequency signal and, in an embodiment, may be a line-of-sight (LoS) signal from the second radar device 300. Therefore, the first radar device 100 can receive the second radar signal 520 directly from the second radar device 300, that is, not as an echo signal or a multipath version of the second radar signal 520. Based on the second radar signal 520, the first radar device 100 detects the pilot signal f pilot , as detailed in the following disclosure. In an embodiment, the detected pilot f pilot is equal to the transmission frequency f of the first radar device 100 Tx1 The transmission frequency f of the second radar device 300 Tx2 The frequency difference between them.

[0072] Then, the first radar device 100 detects the echo signal 510′ of the first radar signal 510 and the detected pilot signal f pilot Determine a predetermined transmission delay of first radar signal 510 relative to second radar signal 520. Figure 2As shown, the first radar device 100 aligns the transmission of the first radar signal 510 with the transmission of the second radar signal 520 by tracking the second radar signal 520 with a predetermined transmission delay. Therefore, the first radar device 100 is synchronized with the second radar device 300, and in addition to the echo signal transmitted from the first radar device 100, the echo signal transmitted from the second radar device 300 can also be used to determine the position of the target object.

[0073] Figure 2 A first radar signal 510 and a second radar signal 520 according to an embodiment of the present invention are shown. The time-varying frequency signals of the first radar signal 510 and the second radar signal 520 may be compressed high intensity radar pulse (CHIRP) signals. The CHIRP signal may be transmitted in frames, each frame including several CHIRPs, and there is a silent period between frames, so it has periodicity. For simplicity, only four CHIRPs are shown per frame, but each frame may include dozens of CHIRPs. In the illustrated embodiment, the CHIRP signal is an up-CHIRP signal, i.e., a signal whose frequency increases over time. However, the CHIRP signal may be changed to a down-CHIRP signal, i.e., a signal whose frequency decreases over time.

[0074] refer to Figure 2 , the triggering of the first radar signal 510 has a time delay relative to the second radar signal 520, that is, there is a trigger offset relative to the second radar signal 520. When the first radar signal 510 is triggered, the transmission frequency f of the first radar signal 510 is different from that of the first radar signal 510. Tx1 In comparison, the transmission frequency f of the second radar signal 520 Tx2 In this way, a pilot frequency f is created at the first radar device 100 that can be observed in the intermediate frequency signal. pilot . Pilot frequency f pilot The position of is related to the trigger offset (i.e., the predetermined transmission delay). The larger the trigger offset, the larger the frequency deviation, resulting in the pilot f pilot The higher. Figure 3 As shown, the higher pilot frequency f pilot This in turn indicates that the target object is farther away than the actual target object, making the pilot frequency f pilot It is easily detected and tracked by the first radar device 100. The frequency and phase difference between the transmitted radar signal and the received echo of the transmitted radar signal produces an intermediate frequency. Figure 3 The left graph shows the IF spectrum, indicating the pilot frequency f pilot With higher frequency and higher intermediate frequency power components, they can be easily detected and filtered out. Figure 3The range / Doppler coordinate diagram on the right shows that in the range / Doppler coordinate diagram, the pilot frequency f corresponding to a high-power, zero-speed (stationary) long-distance target object pilot Can be easily identified from other target objects.

[0075] refer to Figure 2 In each frame, the first radar device 100 first senses the second radar signal 520, and based on the pilot signal f detected from the second radar signal 520 within the alignment period T1, pilot Determine the predetermined transmission delay. Then, the first radar device 100 tracks the second radar signal 520 with the predetermined transmission delay in the tracking time period T2.

[0076] Tracking the second radar signal 520 by the first radar device 100 may include based on the detected pilot signal f pilot Adjusting the transmission frequency f of the first radar device 100 Tx1 . Adjust the transmission frequency f of the first radar device 100 Tx1 It can also include the reference frequency f ref Adjusted to the detected pilot frequency f pilot , and based on the adjusted reference frequency f ref To adjust the transmission frequency f of the first radar device 100 Tx1 . Reference frequency f ref It can be an internal reference frequency of the first radar device 100 when it is running.

[0077] In the embodiment, the transmission frequency f of the first radar device 100 is Tx1 Equal to the adjusted reference frequency f ref Multiply by N / M, that is, f Tx1 =N / M*f ref , where N and M are adjustable positive integers and can be considered as frequency multiplication coefficients or scaling to make the transmission frequency f of the first radar device 100 Tx1 Changes over time.

[0078] The detected pilot f pilot can be equal to the transmission frequency f of the first radar device 100 Tx1 The transmission frequency f of the second radar device 300 Tx2 The frequency difference between them.

[0079] Figure 41 shows a flow chart of a method 200 for a first radar device 100 according to an embodiment of the present invention. The method 200 comprises: transmitting 202 a first radar signal 510 comprising a time-varying frequency signal; receiving 204 a second radar signal 520 from a second radar device 300 during the transmission of the first radar signal 510, the second radar signal 520 comprising a time-varying frequency signal. The method 200 further comprises: detecting 206 a pilot frequency f from the second radar signal 520 pilot Based on the echo signal 510 of the first radar signal 510 'and the detected pilot f pilot A predetermined transmission delay of first radar signal 510 relative to second radar signal 520 is determined 208. Method 200 also includes aligning 210 transmissions of first radar signal 510 with transmissions of second radar signal 520 by tracking second radar signal 520 with the predetermined transmission delay.

[0080] First radar device 100 may be triggered to transmit first radar signal 510 and to start sensing second radar signal 520 in a different manner. Figure 5 It is shown that the first radar device 100 is triggered by a trigger network 600 according to an embodiment of the present invention. In this embodiment, the first radar device 100 receives a trigger signal 610 from the trigger network 600 and transmits a first radar signal 510 based on the received trigger signal 610. The trigger signal 610 can be an electrical pulse indicating the start time of the operation, and can be implemented in different ways. For example, the trigger signal 610 can be implemented using power line communication (PLC), low-speed wireless communication on a frequency band other than radar operation, free space optical communication, or a direct cable connection. The trigger network 600 can be shared by the first radar device 100 and the second radar device 300, and is used to transmit separate trigger signals 610, 610' to the first radar device 100 and the second radar device 300, respectively. The trigger network 600 may be the same network as the data network on which the positioning data 620, 620' of the first radar device 100 and the second radar device 300 are transmitted, or it may not be the same network. Therefore, if Figure 5 As shown by the dashed arrows in FIG. 8 , in an embodiment, the first radar device 100 and / or the second radar device 300 may transmit positioning data 620 , 620 ′ to the trigger network 600 .

[0081] In an embodiment, the first radar device 100 is changed to be based on the detected pilot signal f pilot A trigger signal 610 is determined, and first radar signal 510 is transmitted based on the determined trigger signal 610. In this way, first radar device 100 can internally trigger first radar signal 510 without triggering network 600. Figure 6As shown and explained, first radar device 100 may determine trigger signal 610 by transmitting an intermediate frequency (IF) signal to trigger determination block 130 .

[0082] Figure 6 FIG. 1 is a block diagram of a first radar device 100 according to an embodiment of the present invention. Figure 1 and Figure 2 As described, the first radar device 100 includes a phase alignment block (PAB) 110 for aligning the transmission of the first radar signal 510 with the transmission of the second radar signal 520. The PAB 110 includes a digital signal processor (DSP) 112, a direct digital synthesizer (DDS) 114, a jitter cleaner 116, and a phase lock loop controller (PLL ctrl) 118. The PLL ctrl 118 uses a low frequency reference level of tens of MHz to hundreds of MHz to control a voltage controlled oscillator (VCO) 120 and generates an exemplary 24 GHz frequency CHIRP f Tx1 =N / M*f ref . CHIRP can be based on the adjusted reference frequency f ref The frequency multiplication and division, so the phase is adjusted with the reference frequency f ref The PLL ctrl 118 also converts the output of the VCO 120, that is, the transmission frequency f of the first radar device 100 Tx1 As closed-loop feedback, it ensures that the reference frequency f ref When the second radar signal 520 deviates from the first radar signal 510, the first radar device 100 will detect the relatively high frequency pilot signal f at the intermediate (IF) signal port. pilot and is sampled by DSP 112. Inside DSP 112, an adaptive bandpass filter (BPF) will filter out unwanted signal frequencies and retain the pilot frequency f pilot for further processing.

[0083] The trigger signal 610 is input to the PLL ctrl 118 and enables the generation of the CHIRP signal. Figure 6, trigger signal 610 may be received from trigger network 600 or determined internally in trigger determination block 130, etc. As indicated in FIG. 1 , trigger signal 610 may be received from trigger network 600 or determined internally in trigger determination block 130, etc. Trigger determination block 130 may include a BPF and a power detector. The power detector may be used to determine whether second radar signal 520 is detected. With appropriate design of the BPF, power detection may generate a trigger signal 610 with a certain range of delays associated with sensing of second radar signal 520. Ideally, the delay is equal to a predetermined transmission delay. The BPF and power detector may be hardware blocks and / or digitally implemented as software algorithms in DSP 112. After sensing received second radar signal 520, first radar device 100 may be operated from a free-running mode to a tracking mode as described above, thereby synchronizing with second radar device 300 for transmitting first radar signal 510.

[0084] Figure 7 1 shows the processing structure of the DSP 112 according to an embodiment of the present invention. The DSP 112 and the DDS 114 share the same reference clock to ensure local consistency between the two. The adjustment of the first radar device 100 can be divided into two main steps, namely: sensing and tuning. In the sensing stage, the intermediate frequency (IF) signal is sampled and the pilot frequency f is extracted using the BPF 140. pilot . Pilot frequency f pilot The digital control oscillator (NCO) 142 is used to down-convert the quadrature baseband signals used by the phase detector (PhDet) 144. The amplitude difference between the quadrature baseband signals represents the input pilot frequency f pilot The PhDet 144 analyzes this difference and converts it into phase information. Thereafter, the PhDet 144 determines the phase offset over time and feeds the phase offset error into the loop filter 146 for smoothing and then generates the NCO 142 adjustment signal. The adjustment signal is used to control the NCO 142 frequency. When converged, the NCO 142 is phase locked to the pilot frequency f pilot During the tuning phase, the operating frequency of NCO 142 is coherently adjusted with DDS 114. When the DDS 114 frequency is changed, the PLL ctrl 118 reference frequency is fine-tuned, which affects the generation of the VCO 120 chirp. The chirp change of VCO 120 will affect the intermediate frequency (IF) signal, and the transmission of the first radar signal 510 converges when the CHIRP slope of the first radar signal 510 increases with the same phase as the CHIRP slope of the second radar signal 520.

[0085] Figure 8 A control device 540 for a radar system 500 according to an embodiment of the present invention is shown. The radar system 500 in the disclosed example includes a first radar device 100 and a second radar device 300. In this context, the control device 540 is used to receive a first positioning signal 550 from the first radar device 100. In this regard, the control device 540 can be connected to the first radar device 100 and the second radar device 200 via a suitable communication interface 542, 542'. The first positioning signal 550 indicates a first position of a target object 700. The control device 540 is also used to receive a second positioning signal 560 from the second radar device 300. The second positioning signal 560 indicates a second position of the target object 700. Based on the first position of the object 700 and the second position of the target object 700, the control device 540 determines the final position of the target object 700. The control device 540 can be implemented in hardware, software, or in a combined hardware and software implementation. The control device 540 can be partially or completely integrated with other devices of the radar system 500.

[0086] refer to Figure 8 , the first radar device 100 and the second radar device 300 are in the line of sight of each other. As described above, the first radar device 100 is used to transmit a first radar signal 510 including a time-varying frequency signal, and the second radar device 300 is used to transmit a second radar signal 520 including the time-varying frequency signal, and wherein the first radar signal 510 is transmitted with a predetermined transmission delay relative to the second radar signal 520. Therefore, the transmission of the first radar device 100 is aligned with the transmission of the second radar device 300. Therefore, the first radar device 100 can receive and use the echo signal 510' from its own transmission and the echo signal 520' from the transmission of the second radar device 300 to determine the first positioning signal 550, thereby improving the positioning accuracy.

[0087] refer to Fig. 9 , the range resolution or position accuracy of each radar detection is limited. For example, as long as the target object 700 falls within the first area 710, the first radar device 100 transmits the first radar signal 510 and receives the echo of the first radar signal 510', and determines a fixed detection distance to the object 700. In the same way, for the second radar device 300, when the target object 700 falls within the second area 720, a fixed detection distance is determined regardless of its actual position in the second area 720. When the first radar device 100 and the second radar device 300 are synchronized and the second radar device 300 transmits the second radar signal 520 and is received by the first radar device 100, that is, as Figure 8 As shown in the path 510 to 520', the detection area will be equal to the Fig. 9The third area 730 is an elliptical shape as shown. When all three detection paths are used, the target object 700 must be located in the area where the first area 710, the second area 720, and the third area 730 overlap, which means that a higher detection accuracy is achieved compared to using only the first area 710 and the second area 720. The control device 540 according to the embodiment of the present invention uses the indicated positions from both the first radar device 100 and the second radar device 300, so the final position of the target object 700 can be determined with higher accuracy.

[0088] In the illustrated embodiment, the radar system 500 includes only one first radar device 100 and one second radar device 200. However, the radar system 500 may include any number of first radar devices 100 and second radar devices 300 without departing from the scope of the present invention. A general arrangement may include one or more first radar devices 100 acting as slave radar devices, and thus tracking and following a second radar device 300 acting as a master radar device.

[0089] Therefore, the first radar device 100 can receive the target object echo signal emitted by itself and the target object echo signal from other radar devices aligned with the first radar device. The received echo signal is down-converted into an IF signal by the first radar device 100. By analyzing the frequency components of the IF signal, different target objects can be identified at different frequencies, wherein the lower frequency corresponds to the target object echo signal emitted by itself, and the higher signal audio frequency component corresponds to the radar echo signal emitted by other radar devices. By considering the deployment position of different radar devices, the position of the target object can be identified. Even though the examples discussed herein have been set in an indoor environment, the embodiments of the present invention are not limited thereto. Therefore, the present radar device and radar system can also be deployed in an outdoor environment for tracking and locating different target objects.

[0090] Fig.10 It is shown that the control device 540 (such as Figure 8 4 . The method 400 includes receiving 402 a first positioning signal 550 from the first radar device 100, the first positioning signal 550 indicating a first position of the object 700. The method 400 also includes receiving 404 a second positioning signal 560 from the second radar device 300, the second positioning signal 560 indicating a second position of the object 700. The method 400 includes determining 406 a final position of the object 700 based on the first position of the object 700 and the second position of the object 700.

[0091] In addition, any method according to an embodiment of the present invention can be implemented in a computer program having a code component, which causes the processing component to perform the method steps when the code component is run by the processing component. The computer program is included in a computer-readable medium of a computer program product. The computer-readable medium can basically include any memory, such as the above-mentioned read-only memory (ROM), programmable read-only memory (PROM), erasable PROM (EPROM), flash memory, electrically erasable PROM (EEPROM), hard disk drive, etc.

[0092] In addition, it should be appreciated that the first radar device 100 and the control device 540 include necessary communication capabilities in the form of, for example, functions, components, units, elements, etc., for performing or implementing embodiments of the present invention. Examples of other such components, units, elements and functions are: processors, memories, buffers, control logic, encoders, decoders, rate matchers, derate matchers, mapping units, multipliers, decision units, selection units, switches, interleavers, deinterleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, power supply units, power supply feeds, communication interfaces, communication protocols, etc., which are appropriately arranged together to perform the scheme.

[0093] Specifically, the processor of the first radar device and the control device may include, for example, a central processing unit (CPU), a processing unit, a processing circuit, a processor, an application specific integrated circuit (ASIC), a microprocessor, or one or more instances of other processing logic that can interpret and execute instructions. Therefore, the expression "processor" can represent a processing circuit including multiple processing circuits, such as any, part or all of the above-mentioned processing circuits. The processing circuit system can also perform data processing functions for inputting, outputting and processing data, and the data processing functions include data buffering and device control functions, such as call processing control, user interface control, etc.

[0094] Finally, it should be understood that the present invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the attached independent claims.

Claims

1. A first radar device (100) for a radar system (500), characterized in that: The first radar device (100) is used for: Transmitting a first radar signal including a time-varying frequency signal (510); receiving a second radar signal (520) from a second radar device (300) during the transmitting of the first radar signal (510), wherein the second radar signal (520) includes the time-varying frequency signal; A pilot signal (f pilot ); Based on the echo signal (510') of the first radar signal (510) and the detected pilot signal (f pilot ) determining a predetermined transmission delay of the first radar signal (510) relative to the second radar signal (520); The transmission of the first radar signal (510) is aligned with the transmission of the second radar signal (520) by tracking the second radar signal (520) with the predetermined transmission delay.

2. The first radar device (100) according to claim 1, characterized in that The time-varying frequency signal is a Compressed High Intensity Radar Pulse (CHIRP) signal.

3. The first radar device (100) according to claim 2, characterized in that The CHIRP signal is an uplink CHIRP signal.

4. The first radar device (100) according to any one of the preceding claims, characterized in that The second radar signal (520) is a line-of-sight signal from the second radar device (300).

5. The first radar device (100) according to any one of the preceding claims, characterized in that The tracking of the second radar signal (520) includes: Based on the detected pilot signal (f pilot ) adjusting the transmission frequency (f Tx1 ).

6. The first radar device (100) according to claim 5, characterized in that The adjusting of the transmission frequency (f Tx1 )include: The reference frequency (f ref ) is adjusted to the detected pilot (f pilot ); Based on the adjusted reference frequency (f ref ) adjusting the transmission frequency (f Tx1 ).

7. The first radar device (100) according to claim 6, characterized in that The transmission frequency (f Tx1 ) is equal to the adjusted reference frequency (f ref ) multiplied by N / M, where N and M are adjustable positive integers.

8. The first radar device (100) according to any one of the preceding claims, characterized in that The detected pilot (f pilot ) is equal to the transmission frequency (f Tx1 ) and the transmission frequency (f Tx2 ) is the frequency difference between them.

9. The first radar device (100) according to any one of claims 1 to 8, characterized in that Used for Receiving a trigger signal (610) from a trigger network (600); The first radar signal (510) is transmitted based on the received trigger signal (610).

10. The first radar device (100) according to any one of claims 1 to 8, characterized in that Used for Based on the detected pilot signal (f pilot ) determine the trigger signal (610); The first radar signal (510) is transmitted based on the determined trigger signal (610).

11. A control device (540) for a radar system (500), characterized in that: The radar system (500) comprises a first radar device (100) according to any one of the above claims, and a second radar device (300); the control device (510) is used for: receiving a first positioning signal (550) from the first radar device (100), the first positioning signal (550) indicating a first position of an object (700); receiving a second positioning signal (560) from the second radar device (300), the second positioning signal (560) indicating a second position of the object (700); A final position of the object (700) is determined based on the first position of the object (700) and the second position of the object (700).

12. The control device (540) according to claim 11, characterized in that The first radar device (100) and the second radar device (300) are within line of sight of each other.

13. The control device (540) according to claim 11 or 12, characterized in that: The first radar device (100) is used to transmit a first radar signal (510) including a time-varying frequency signal, and the second radar device (300) is used to transmit a second radar signal (520) including the time-varying frequency signal, wherein the first radar signal (510) is transmitted with a predetermined transmission delay relative to the second radar signal (520).

14. A method (200) for a first radar device (100), characterized in that The method (200) comprises: transmitting (202) a first radar signal (510) comprising a time varying frequency signal; receiving (204) a second radar signal (520) from a second radar device (300) during said transmitting of said first radar signal (510), said second radar signal (520) comprising said time-varying frequency signal; A pilot signal (f pilot ); Based on the echo signal (510') of the first radar signal (510) and the detected pilot signal (f pilot ) determining (208) a predetermined transmission delay of the first radar signal (510) relative to the second radar signal (520); The transmission of the first radar signal (510) is aligned (210) with the transmission of the second radar signal (520) by tracking the second radar signal (520) with the predetermined transmission delay.

15. A method (400) for a control device (540) of a radar system (500), characterized in that: The radar system (500) comprises a first radar device (100) according to any one of the above claims, and a second radar device (300), and the method (400) comprises: receiving (402) a first positioning signal (550) from the first radar device (100), the first positioning signal (550) indicating a first position of an object (700); receiving (404) a second positioning signal (560) from the second radar device (300), the second positioning signal (560) indicating a second position of the object (700); A final position of the object (700) is determined (406) based on the first position of the object (700) and the second position of the object (700).

16. A computer program comprising program code, characterized in that When the computer program is run on a computer, the program code is used to execute the method according to claim 14 or 15.

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