Radar device, radar signal generation circuit, and transmission method

Abstract

To provide a radar apparatus capable of efficiently detecting a target.SOLUTION: The radar apparatus includes: a first radar circuit that transmits a first transmission signal; and a second radar circuit that transmits a second transmission signal. Multiple transmission cycles transmitting the first transmission signal and the second transmission signal include: a first transmission cycle in which frequency-division multiplexing transmission of the first transmission signal and the second transmission signal is performed; and a second transmission cycle in which the first transmission signal and the second transmission signal are transmitted at the same frequency.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a radar device and a transmission method. [Background technology]

[0002] In recent years, radar devices using short-wavelength radar transmission signals (hereinafter also referred to as TxSig) including microwaves or millimeter waves that can provide high resolution have been studied. For example, a radar device has been proposed that includes multiple antennas (array antennas) in the transmitter as well as the receiver, and performs beam scanning by signal processing using the transmitting and receiving array antennas (sometimes referred to as MIMO (Multiple Input Multiple Output) radar) (see, for example, Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Publication No. 2020 / 0300965 [Patent Document 2] International Publication No. 2023 / 074275 [Patent Document 3] JP 2020-148754 A [Patent Document 4] JP 2020-204603 A [Non-patent literature]

[0004] [Non-Patent Document 1] J. Li, and P. Stoica, "MIMO Radar with Colocated Antennas", Signal Processing Magazine, IEEE Vol. 24, Issue: 5, pp. 106-114, 2007 [Non-Patent Document 2] E. Fishler, A. Haimovich, R. Blum, D. Chizhik, L. Cimini and R. Valenzuela, "MIMO radar: an idea whose time has come," Proceedings of the 2004 IEEE Radar Conference, 2004, pp. 71-78. [Non-Patent Document 3] M. Kronauge, H. Rohling, "Fast two-dimensional CFAR procedure", IEEE Trans. Aerosp. Electron. Syst., 2013, 49, (3), pp. 1817-1823 [Non-Patent Document 4] Direction-of-arrival estimation using signal subspace modeling Cadzow, JA; Aerospace and Electronic Systems, IEEE Transactions on Volume: 28 , Issue: 1 Publication Year: 1992 , Page(s): 64 - 79 [Non-Patent Document 5] H. Yan, J. Li and G. Liao, “Multitarget Identification and Localization Using Bistatic MIMO Radar Systems,” EURASIP Journal on Advances in Signal Processing, vol. 2008, Article ID 283483, 8 pages, 2008. Summary of the Invention [Problem to be solved by the invention]

[0005] However, a method for detecting a target in a radar device (eg, a MIMO radar) has not been fully considered.

[0006] Non-limiting embodiments of the present disclosure contribute to providing a radar device and a transmission method that can efficiently detect a target. [Means for solving the problem]

[0007] A radar device according to one embodiment of the present disclosure includes a first radar circuit that transmits a first transmission signal and a second radar circuit that transmits a second transmission signal, and a plurality of transmission periods in which the first transmission signal and the second transmission signal are transmitted include a first transmission period in which the first transmission signal and the second transmission signal are frequency division multiplexed and a second transmission period in which the first transmission signal and the second transmission signal are transmitted at the same frequency.

[0008] In addition, these comprehensive or specific embodiments may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. Effect of the Invention

[0009] According to an embodiment of the present disclosure, a radar device can efficiently detect a target.

[0010] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief description of the drawings]

[0011] [Figure 1] A diagram showing an example of a radar device with a mono-static and multi-static configuration. [Diagram 2] A block diagram showing a configuration example of a radar device. [Diagram 3] A block diagram showing a configuration example of a radar device. [Figure 4]FIG. 1 shows an example of a transmission signal. [Diagram 5] A diagram showing an example of a chirp signal. [Figure 6] A diagram showing an example of Doppler multiplexing [Figure 7] A diagram showing an example of Doppler multiplexing [Figure 8] A diagram showing an example of Doppler multiplexing [Figure 9] A diagram showing an example of Doppler multiplexing [Figure 10] A diagram showing an example of Doppler multiplexing [Figure 11] A diagram showing an example of Doppler multiplexing [Figure 12] A diagram showing an example of Doppler multiplexing [Figure 13] A diagram showing an example of Doppler multiplexing [Figure 14] A diagram showing an example of received Doppler during Doppler multiplex transmission. [Figure 15] FIG. 1 shows an example of a transmission signal. [Figure 16] A block diagram showing a configuration example of a receiving unit of a radar device. [Figure 17] FIG. 1 shows an example of a transmission signal. [Figure 18] A block diagram showing a configuration example of a receiving unit of a radar device. [Figure 19] FIG. 1 shows an example of a transmission signal. [Figure 20] A block diagram showing a configuration example of a receiving unit of a radar device. [Figure 21] A block diagram showing an example of the configuration of a portion of a radar device. [Figure 22] FIG. 1 shows an example of a transmission signal. [Figure 23] FIG. 1 shows an example of a transmission signal. [Figure 24] FIG. 1 shows an example of a transmission signal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] MIMO radars are broadly classified into, for example, a "monostatic configuration" and a bistatic or multistatic configuration (hereinafter referred to as a "bi- / multistatic configuration"). Hereinafter, the monostatic configuration will be referred to as an "MNS configuration" and the bi- / multistatic configuration will be referred to as a "BMS configuration."

[0013] In the MNS configuration, for example, a transmitter (eg, including a plurality of transmitting antennas and a high-frequency radio unit) and a receiver (eg, including a plurality of receiving antennas and a high-frequency radio unit) may be included in the same housing.

[0014] Also, in the BMS configuration, for example, the transmitter and the receiver may be included in different housings. For example, in the BMS configuration, each housing is installed at a distance away, and the transmitter and the receiver are connected to a control unit that performs synchronous control. In the bistatic configuration, for example, the transmitter and the receiver are paired, and the transmitter and the receiver are configured at a distance away from each other. In the multistatic configuration, for example, there are multiple transmitters and / or multiple receivers. The multistatic configuration is disclosed in, for example, Non-Patent Document 2.

[0015] Hereinafter, in a non-limiting embodiment of the present disclosure, attention will be given to the BMS configuration. For example, in a non-limiting embodiment of the present disclosure, a BMS configuration using a MIMO radar with a plurality of MNS configurations will be described. The BMS configuration using a MIMO radar with a plurality of MNS configurations may be called, for example, a "mono- and multi-static configuration."

[0016] FIG. 1 shows an example of a radar device with a mono- and multistatic configuration in which radar #1 and radar #2, which are MIMO radars with an MNS configuration, are used.

[0017] Radar #1 is, for example, a “first MNS-configured MIMO radar” that outputs radar transmission waves (also called TxSig) from a radar transmitting antenna group Tx #1 and receives reflected wave signals from a target #1 by a radar receiving antenna group Rx #1 in the same housing (e.g., path (1)).

[0018] Similarly, radar #2 is, for example, a “second MNS-configured MIMO radar” that outputs radar transmission waves from a radar transmitting antenna group Tx #2 and receives reflected wave signals from a target #3 by a radar receiving antenna group Rx #2 in the same housing (e.g., path (2)).

[0019] 1 may transmit radar transmission waves from a group of transmitting antennas Tx#1 of radar #1 and receive reflected wave signals from a target #2 at a group of receiving antennas Rx#2 of radar #2. A radar device that performs this operation may be regarded as, for example, a "MIMO radar with a first BMS configuration" (e.g., path (3)).

[0020] Similarly, the radar #2 may transmit radar transmission waves from the transmitting antenna group Tx#2 and receive reflected wave signals from the target #2 at the receiving antenna group Rx#1 of the radar #1. A radar device that performs this operation may be regarded as, for example, a "MIMO radar with a second BMS configuration" (e.g., path (4)).

[0021] To use the radar as a BMS radar in addition to the MNS radar, for example, a synchronization unit may be used that performs synchronization control between a plurality of MNS radars installed at distant locations. For example, in FIG. 1, when a frequency modulated FMCW (Frequency modulated continuous wave) signal (e.g., a "chirp signal") is used as a radar transmission wave, the synchronization unit may generate a chirp signal and supply the chirp signal to radar #1 and radar #2 in common. This allows the radar to be used as a first MNS MIMO radar and a second MNS MIMO radar, and also allows the radar to be used as a first BMS MIMO radar and a second BMS MIMO radar.

[0022] The synchronization unit may generate a plurality of different chirp signals and supply the different chirp signals to the radar #1 and the radar #2, respectively. However, if the chirp signals are transmitted with a frequency difference that causes the center frequencies of the plurality of different chirp signals to be outside the mutual reception bands of the radar #1 and the radar #2, it is difficult to use the chirp signals as the MIMO radars having the first and second BMS configurations.

[0023] The radar device shown in FIG. 1 may generate TxSig in the synchronization section and supply TxSig in common to radar #1 and radar #2.

[0024] For example, if the first and second MNS radars operate simultaneously using the same radar transmission waves, they may interfere with each other, making false detection or non-detection more likely to occur, and the positioning accuracy or detection performance of the radar may deteriorate. Therefore, for example, multiplexing transmission that applies time division multiplexing (TDM), frequency division multiplexing (FDM), or code division multiplexing (CDM) may be applied to the transmission of radar in a BMS configuration using the first and second MNS radars.

[0025] Regarding radar transmission using a BMS configuration, for example, application of time division or frequency division transmission is disclosed in, for example, Patent Document 1 or Patent Document 2, and the following cases are assumed for each.

[0026] In time-division transmission in the BMS configuration, for example, after the end of transmission from radar #1 to radar #2 in the BMS configuration, the transmission is switched to from radar #2 to radar #1 in the BMS configuration, so the time required for transmission processing in both the MNS configuration and the BMS configuration is likely to increase, and tracking performance during target movement is likely to deteriorate. In addition, for example, when time-division transmission is performed between radar #1 and radar #2 for each chirp signal transmission period (Tr), the radar device shown in Figure 1 performs Doppler frequency analysis of the reflected wave signal every two chirp signal transmission periods (2Tr), so the maximum detectable Doppler is likely to be reduced, and the Doppler frequency range is reduced to ±1 / (4Tr). In the following, Doppler frequency is also referred to as "DFreq".

[0027] Furthermore, for example, when frequency multiplexing transmission is performed in a BMS configuration (for example, chirp signals are transmitted with a frequency difference that is outside the mutual reception bands of radar #1 and radar #2) and all receiving antennas of radar #1 or radar #2 perform reception processing of the transmitting antennas of the radar, reception in the first and second BMS configurations is difficult. On the other hand, for example, when some of the receiving antennas of radar #1 or radar #2 perform reception processing of a transmission signal with a frequency different from the transmission signal of the radar, the number of receiving antennas that receive the reflected wave signal from the transmission signal of the radar is reduced. For this reason, the radar device shown in FIG. 1 is prone to a decrease in the received signal level or a deterioration in the angle measurement accuracy.

[0028] In a non-limiting embodiment of the present disclosure, a method for improving the efficiency of target detection in a mono- and multi-static configuration is described. For example, in a non-limiting embodiment of the present disclosure, a multiplexing method is described that maintains radar detection performance (e.g., detectable DFreq range) in an MNS configuration, enables simultaneous multiplexing in a BMS configuration in addition to the MNS configuration, and shortens the time required for radar ranging.

[0029] For example, in a non-limiting embodiment of the present disclosure, in addition to the MNS-configured radar positioning of radar #1 and radar #2 shown in FIG. 1, BMS-configured radar positioning from radar #1 to radar #2 and BMS-configured radar positioning from radar #2 to radar #1 may be performed simultaneously.

[0030] For example, as multiplex transmission in a BMS configuration, frequency division multiplexing (FDM) transmission and same-frequency transmission may be applied alternately at a predetermined period (hereinafter, sometimes referred to as "partial frequency division multiplexing (P-FDM) transmission between BMSs").

[0031] Also, for example, all of the receiving antennas of radar #1 or radar #2 may perform receiving processing for the transmitting antennas of that radar.

[0032] The radar device according to an embodiment of the present disclosure may be mounted on a moving body such as a vehicle. For example, the radar device may be mounted near a corner of at least one of the front and rear of the vehicle, or near the center of at least one of the front and rear of the vehicle or from the center to the corner.

[0033] The positioning output (information regarding the estimation results) of the radar device mounted on the moving body may be output to a control ECU (Electronic Control Unit) (not shown), such as an Advanced Driver Assistance System (ADAS) that improves collision safety or an autonomous driving system, and may be used for vehicle drive control or alarm call control.

[0034] Moreover, the radar device according to an embodiment of the present disclosure may be attached to a relatively high structure (not shown), such as a roadside utility pole or a traffic light. Such a radar device may be used, for example, as a sensor in a support system for improving the safety of passing vehicles or pedestrians, or in a system for preventing intrusion of suspicious persons. Furthermore, the positioning output of the radar device may be output to a control device (not shown) in the support system for improving safety or the system for preventing intrusion of suspicious persons, and may be used for alarm generation control or abnormality detection control.

[0035] The uses of the radar device are not limited to these, and the device may be used for other purposes.

[0036] Moreover, a target is an object to be detected by a radar device, and includes, for example, vehicles (including four-wheeled and two-wheeled vehicles), people, blocks, curbs, and the like.

[0037] Hereinafter, an embodiment according to an example of the present disclosure will be described in detail with reference to the drawings. In the embodiment, the same components are denoted by the same reference numerals, and the description thereof will be omitted to avoid duplication.

[0038] The following describes a configuration (e.g., a MIMO radar configuration) in which a radar device transmits different transmit signals simultaneously multiplexed from multiple transmit antennas in a transmit branch, and a receive branch separates each transmit signal for receiving processing.

[0039] In addition, the following describes, as an example, the configuration of a radar system using a frequency-modulated pulse wave such as a chirp pulse (also called fast chirp modulation). However, the modulation system is not limited to frequency modulation. For example, an embodiment of the present disclosure is also applicable to a radar system using a pulse compression radar that transmits a pulse train after phase modulation or amplitude modulation.

[0040] (Embodiment) [Radar device configuration] The radar device (also called a radar system) according to this embodiment may have, for example, a plurality of radar units (corresponding to radar circuits, for example, MIMO radar). The radar device according to this embodiment may also have, for example, a synchronization unit (corresponding to a control circuit, for example) that performs synchronization control between the plurality of radar units, and an integration unit that integrates the positioning outputs of the plurality of radar units.

[0041] For example, the radar device 1 shown in FIG. 2 is a radar system including a first radar section 10 (or radar section 10-1) having multiple transmitting and receiving antennas (not shown), and a second radar section 10 (or radar section 10-2) having multiple transmitting and receiving antennas (not shown).

[0042] 2, the synchronization unit 20 performs synchronization control between the first radar unit 10 and the second radar unit 10. For example, the synchronization unit 20 may generate a chirp signal or a reference clock signal (also called a reference signal) as a synchronization control signal to the first radar unit 10 and the second radar unit 10 for the synchronization control.

[0043] Here, the reference signal is, for example, a reference signal of a VCO (Voltage Controlled Oscillator) that generates a chirp signal, and is a high-frequency signal of about several tens to several hundreds of MHz. When the synchronization unit 20 uses a reference signal as a synchronization control signal, the system cost can be reduced compared to when a chirp signal (for example, on the order of GHz) is used. When the synchronization unit 20 uses a reference signal, the chirp signal is generated individually in each of the first radar unit 10 and the second radar unit 10, so that the matching of the phases of the first radar unit 10 and the second radar unit 10 is not guaranteed, and a phase shift that causes a drift and displacement is likely to occur. The radar device 1 may, for example, measure and correct the drift component of the phase between the first radar unit 10 and the second radar unit 10 in advance.

[0044] For example, the radar device 1 may transmit a transmission signal from multiple transmission antennas of a transmission unit 100-1 of the first radar unit 10. For example, the radar device 1 may receive a reflected wave signal, which is the transmission signal of the first radar unit 10 reflected by a target #1 (corresponding to the target #1 in FIG. 1), in a reception unit 200-1 having multiple reception antennas of the first radar unit 10, and perform a positioning process of the target #1 (for example, radar positioning using an MNS configuration).

[0045] Furthermore, the radar device 1 may receive, for example, a reflected wave signal, which is the transmission signal of the first radar unit 10 reflected by target #2 (corresponding to target #2 in Figure 1), in a receiving unit 200-2 having multiple receiving antennas of the second radar unit 10, and perform positioning processing of target #2 (for example, radar positioning using a BMS configuration).

[0046] Similarly, for example, the radar device 1 may transmit a transmission signal from multiple transmitting antennas of the radar transmitter 100-2 of the second radar unit 10. For example, the radar device 1 may receive a reflected wave signal, which is the transmission signal of the second radar unit 10 reflected by a target #3 (corresponding to the target #3 in FIG. 1), in the receiver 200-2 having multiple receiving antennas of the second radar unit 10, and perform a positioning process of the target #3 (for example, radar positioning using an MNS configuration).

[0047] Furthermore, the radar device 1 may receive, for example, a reflected wave signal, which is a transmission signal of the second radar unit 10 reflected by target #2 (corresponding to target #2 in Figure 1), in a receiving unit 200-1 having multiple receiving antennas of the first radar unit 10, and perform positioning processing of target #2 (for example, radar positioning using a BMS configuration).

[0048] The reception processing in the first radar unit 10 and the second radar unit 10 may be performed using, for example, a MIMO virtual antenna.

[0049] Furthermore, in this embodiment, the radar device 1 may multiplex the transmission signal transmitted from the first radar section 10 and the transmission signal transmitted from the second radar section 10.

[0050] For example, each of the first radar unit 10 and the second radar unit 10 may have a separation unit that separates, from the received signal, a reflected wave signal corresponding to a transmission signal from the transmission unit 100 of that radar unit, and separates a reflected wave signal corresponding to a transmission signal from the transmission unit 100 of the other radar unit.

[0051] Also, for example, each of the first radar unit 10 and the second radar unit 10 may have a first angle measurement unit that performs angle measurement using a reflected wave signal of a transmission signal from the transmission unit 100 of the radar unit separated in the separation unit, and a second angle measurement unit that performs angle measurement using a reflected wave signal of a transmission signal from the transmission unit 100 of the other radar unit separated in the separation unit.

[0052] 2, the integrating unit 30 may perform target positioning by integrating, for example, the positioning output (e.g., the first and second positioning outputs) from the first radar unit 10 and the positioning output (e.g., the first and second positioning outputs) from the second radar unit 10. Note that the positioning is information including the direction, distance, and Doppler frequency, and may further include separation index information of the Doppler multiplexed signal (details will be described later).

[0053] With this configuration, the radar device 1 receives the reflected wave signals at the receiving units 200-1 and 200-2, separates the received signals depending on whether they are reflected wave signals due to a transmission signal from its own radar unit or due to a transmission signal from another radar unit, and can appropriately perform positioning processing based on the position information of the first radar unit 10 and the second radar unit 10. Furthermore, the radar device 1 alternates between FDM transmission and same-frequency transmission at a predetermined cycle, so that the positioning time can be shortened compared to the case of time division multiplexing transmission.

[0054] 2, the first radar unit 10 and the second radar unit 10 may be installed at locations separate from each other. In this case, the radar device 1 can be used as a so-called BMS configuration. For example, radar positioning with a BMS configuration in which the first transmission signal from the first radar unit 10 is received at the receiving unit 200-2 of the second radar unit 10 and radar positioning with a BMS configuration in which the second transmission signal from the second radar unit 10 is received at the receiving unit 200-1 of the first radar unit 10 can be performed simultaneously, and the positioning time can be shortened compared to the case of time division multiplexing transmission.

[0055] In addition, since the first radar section 10 and the second radar section 10 shown in FIG. 2 have similar configurations, they will be collectively referred to and described below as the “radar section 10,” and different operations between the first radar section 10 and the second radar section 10 will be distinguished and described.

[0056] FIG. 3 shows an example of the configuration of a radar device 1 that uses a frequency-modulated chirp signal as a radar transmission wave.

[0057] The radar device 1 in Fig. 3 shows details of the first radar unit 10-1 and the synchronization unit 20 in Fig. 2. For example, the first radar unit 10-1 corresponds to the radar unit 10. Note that Fig. 3 shows a configuration example that also supports radars other than the first radar unit 10-1 and the second radar unit 10-2 in Fig. 2, and the other radar units 10 are omitted.

[0058] The radar unit 10 includes, for example, a transmission unit (corresponding to a transmission branch or a radar transmission circuit) 100 and a reception unit (corresponding to a reception branch or a radar reception circuit) 200.

[0059] The transmitter 100 transmits, for example, TxSig generated by the synchronization unit 20 at a predetermined transmission cycle using a transmission array antenna constituted by a plurality of transmission antennas 102-1 to 102-Nt.

[0060] The receiving unit 200 receives, for example, a reflected wave signal, which is TxSig reflected by a target (corresponding to targets #1 to #3 in FIG. 1), using a receiving array antenna including multiple receiving antennas 202-1 to 202-Na. The receiving unit 200 performs signal processing on the reflected wave signal received by each receiving antenna 202, and performs, for example, detection of the presence or absence of the target or positioning.

[0061] The synchronization unit 20 generates, for example, a chirp signal and supplies it to the multiple radar units 10.

[0062] [Example of configuration of synchronization unit 20] The synchronization unit 20 includes, for example, a generation unit 301 and a control unit 304 .

[0063] The generating unit 301 generates TxSig, for example, under control of the control unit 304. The generated TxSig may be, for example, a predetermined frequency modulated wave (for example, a frequency chirp signal or a chirp signal). The generating unit 301 outputs the generated chirp signal to multiple radar units 10 (for example, the transmitting unit 100).

[0064] The generating unit 301 includes, for example, a modulating signal generating unit 302 and a VCO 303. Each component of the generating unit 301 will be described below.

[0065] The modulation signal generating unit 302 periodically generates a modulation signal having, for example, a sawtooth shape. Here, the transmission period of TxSig is denoted as Tr.

[0066] The VCO 303 generates a chirp signal based on the modulated signal output from the modulated signal generating unit 302, and outputs it to the transmitting unit 100 (for example, Doppler shift units 101-1 to 101-Nt) and the receiving unit 200 (a mixer unit 204 described later) of the radar unit 10. Hereinafter, the Doppler shift unit is also referred to as a DS unit.

[0067] For example, in the case of P-FDM transmission, the generating unit 301 outputs, in the case of FDM transmission, a chirp signal which is the output of the VCO 303, and a chirp signal having a different center frequency obtained by frequency-converting the output of the VCO 303. Alternatively, in the case of FDM transmission, the generating unit 301 may output chirp signals having different center frequencies using a plurality of VCOs 303 (not shown).

[0068] The control unit 304 controls the generation unit 301 (for example, the modulation signal generation unit 302 and the VCO 303) to generate TxSig. For example, the control unit 304 controls the generation unit 301 to generate a chirp signal for each transmission period Tr for one radar positioning. c Parameters (eg, modulation parameters) for the chirp signal may be set to transmit the chirp signal a number of times.

[0069] Furthermore, the control unit 304 may set parameters related to the chirp signal so that the center frequency of the chirp signal is variably set so that FDM transmission in the BMS configuration and same-frequency transmission are applied alternately at a predetermined period.

[0070] In the BMS configuration, the center frequency of the chirp signal by the same frequency transmission may include a frequency that coincides with the center frequency of the chirp signal by the FDM transmission. This makes it possible to apply a method of expanding the Doppler detection range using the phase difference of the received signal in the DFreq determination (or the DFreq aliasing determination) described later.

[0071] In addition, in the BMS configuration, the center frequency of the chirp signal by the same frequency transmission may include a difference of a predetermined frequency or more from the center frequency of the chirp signal by the FDM transmission. This makes it possible to apply a method of expanding the Doppler detection range using the DFreq difference of the received signal in the DFreq determination described later.

[0072] Hereinafter, the control unit 304 defines a predetermined transmission period in which FDM transmission and same frequency transmission in the BMS configuration are switched as “N sw ×Tr". N sw is a predetermined integer value equal to or greater than 2.

[0073] 4(a) shows an example of a chirp signal output from the synchronization unit 20 of the first radar unit 10, and FIG. 4(b) shows an example of a chirp signal output from the synchronization unit 20 of the second radar unit 10. As shown in FIG. 4, a plurality of transmission periods (for example, N sw ×Tr), for example, odd-numbered transmission periods (corresponding to the first transmission period) in which FDM transmission is performed and even-numbered transmission periods (corresponding to the second transmission period) in which same-frequency transmission is performed are set alternately.

[0074] The chirp signal generated by the generating unit 301 of the synchronization unit 20 is output to the transmitting unit 100 and the receiving unit 200 of the radar unit 10. In the example of FIG. 4, the control unit 304 sets modulation parameters of the chirp signal so that the center frequency of the chirp signal is varied for each transmission period Tr, so that FDM transmission and same-frequency transmission are alternately switched for each transmission period Tr (for example, N sw =2).

[0075] 4(a), for the chirp signal output from the synchronization unit 20 to the first radar unit 10, the center frequency of the chirp signal in odd-numbered transmission periods is set to fc(2)=fc(1)+Δfc, and the center frequency of the chirp signal in even-numbered transmission periods is set to fc(1). Also, in FIG. 4(b), for the chirp signal output from the synchronization unit 20 to the second radar unit 10, the center frequency of the chirp signal in odd-numbered and even-numbered transmission periods is set to a constant value of fc(1).

[0076] For example, the radar device 1 transmits a chirp signal whose center frequency alternates every transmission period Tr, and measures the reflected wave signal of the chirp signal reflected by the target multiple times, thereby detecting the time variation of the target positioning result. c Transmission period T r Each transmission period is represented by an index "m", where m=1 to N c is an integer.

[0077] As shown in FIG. 5, the modulation parameters for the chirp signal include, for example, a center frequency f c , frequency sweep bandwidth B w , sweep start frequency f cstart , sweep end frequency f cend , frequency sweep time T sw , and the frequency sweep rate of change D m may be included. Note that D m =B w / T sw Also, B w = f cend -f cstart and f c =(f cstart +f cend ) / 2.

[0078] Also, the frequency sweep time T sw The frequency sweep time T corresponds to, for example, a time range (also called a range gate) for capturing A / D sample data in the A / D conversion unit 207 of the receiving unit 200, which will be described later. sw may be set to the entire section of the chirp signal as shown in FIG. 5(a) or to a part of the section of the chirp signal as shown in FIG. 5(b).

[0079] Note that while Figures 4 and 5 show examples of up-chirp waveforms in which the modulation frequency gradually increases over time, down-chirp waveforms may also be applied, and regardless of which is used, the present disclosure can achieve similar effects.

[0080] Each chirp signal output from the synchronization unit 20 is input, for example, to each mixer unit 204 of the receiving unit 200 and to the Nt DS units 101, respectively.

[0081] [Example of configuration of the transmitting unit 100] In Fig. 3, the transmitting unit 100 of the radar unit 10 has, for example, DS units 101-1 to 101-Nt and transmitting antennas 102-1 to 102-Nt (for example, Tx#1 to Tx#Nt). Note that each transmitting antenna 102 may be connected to an individual DS unit 101. Also, the radar unit 10 in Fig. 3 corresponds to the first radar unit 10, but hereinafter, the radar unit 10 including the second radar unit 10 and onwards will be referred to as the qth radar unit 10. Here, q indicates an index for identifying the multiple radar units 10 included in the radar device 1, and may be, for example, q=1 or 2. In the following description, each element included in the qth radar unit 10 will be described with "-q" added.

[0082] The DS unit 101 of the q-th radar unit 10 calculates a Doppler shift amount (hereinafter also referred to as a “DS amount”) DOP n In order to give (q), the transmission period of the chirp signal T r Phase rotation Φ n,q and outputs the Doppler-shifted signal to the transmitting antenna 102.

[0083] Also, for example, the number of transmitting antennas 102 in each of the q-th radar units 10 may be the same or different. Hereinafter, the number of transmitting antennas in the q-th radar unit 10 is represented as "Nt(q)" (or simply "Nt"). Here, Nt(q)≧1. Also, n=1 to Nt(q).

[0084] For example, the q-th radar unit 10 may have a predetermined phase rotation φ that imparts a different Doppler shift to each of the transmitting antennas 102 used for multiplexing in the MNS configuration. n,q (m) may be added and output (an example of operation will be described later).

[0085] In addition, the q-th radar unit 10 performs a predetermined phase rotation Φ that imparts a Doppler shift that results in a different DS amount pattern between the radar units 10 that perform multiplex transmission in a BMS configuration, for example. n,q(m) and output the signal (an operation example will be described later). For example, the pattern of each DS amount (also called Doppler shift pattern) added to the TxSig transmitted from each of the multiple transmitting antennas 102 of the first radar unit 10 may be different from the pattern of each DS amount in the second radar unit 10. The DS amount pattern may be set according to, for example, at least one of the Doppler multiplexing interval (also called Doppler shift interval or Doppler interval; also referred to as "DDM interval") and the Doppler multiplexing number (hereinafter also referred to as "DDM number"). Alternatively, the qth radar unit 10 may, for example, apply a predetermined phase rotation Φ that adds a Doppler shift that results in the same DS amount pattern (for example, the same DDM interval) between radar units 10 that perform multiplexing transmission in a BMS configuration. n,q (m) may be added and output (an example of operation will be described later).

[0086] The output signal of the DS unit 101 is amplified to a predetermined transmission power and radiated into space from each transmitting antenna 102 (for example, Tx#1 to Tx#Nt).

[0087] [Example of configuration of receiving unit 200] 3, the receiver 200 includes Na receiving antennas 202 (for example, Rx#1 to Rx#Na) to configure an array antenna. The receiver 200 also includes Na system processors 201, a CFAR (Constant False Alarm Rate) unit 210, a separator 211, a determiner 212, and an angle measuring unit 213.

[0088] Here, the number of receiving antennas 202 in each of the q-th radar units 10 may be the same or different. Hereinafter, the number of receiving antennas in the q-th radar unit 10 is represented as "Na(q)" (or simply "Na"), where Na(q) is ≧1.

[0089] The system processing unit 201 may be provided corresponding to each of the Na(q) receiving antennas 202. The CFAR unit 210, the separator 211, and the angle measurement unit 213 may be provided corresponding to each of the q radar units 10, for example.

[0090] Each of the Na(q) receiving antennas 202 receives a reflected wave signal that is generated when TxSig transmitted from each of the multiple radar units 10 is reflected by a target (e.g., a reflecting object including a radar measurement target), and outputs the reflected wave signal to the corresponding system processing unit 201 as a received signal.

[0091] Each system processing unit 201 includes a radio reception unit 203 and an analysis unit 206 .

[0092] The receiving radio unit 203 has a mixer unit 204 and an LPF (low pass filter) 205. In the receiving radio unit 203, the mixer unit 204 mixes the received reflected wave signal (received signal) with a chirp signal, which is a transmitted signal. In addition, by passing the output of the mixer unit 204 through the LPF 205, a beat signal is extracted, the frequency of which corresponds to the delay time of the reflected wave signal. For example, the difference frequency between the frequency of the transmitted signal (transmitted frequency modulated wave) and the frequency of the received signal (received frequency modulated wave) is obtained as the beat frequency (or beat signal). Note that the beat frequency is within the passband of the LPF 205.

[0093] Here, signals outside the passband of LPF 205 are attenuated and are not received by the receiving unit 200. For example, in the BMS configuration, a reflected wave signal by FDM transmission from the first radar unit 10 has a frequency difference Δfc (fc(2)-fc(1) in FIG. 4) that is outside the passband of LPF 205 of the second radar unit 10, and is therefore not received by the receiving unit 200 of the second radar unit 10.

[0094] In FIG. 3, the analysis unit 206 of each system processing unit 201-z (where z=1 to Na(q)) has an A / D conversion unit 207, a beat analysis unit 208, and a Doppler analysis unit 209 (also called a “DA unit”).

[0095] The signal (eg, beat signal) output from the LPF 205 is converted by the A / D converter 207 in the analyzer 206 into discrete sample data that has been discretely sampled.

[0096] The beat analysis unit 208 analyzes the transmission period T r For each time, N data The discrete sample data are subjected to FFT processing. Here, the range gate is a frequency sweep time T sw may be set. As a result, the analysis unit 206 outputs a frequency spectrum in which a peak appears at a beat frequency corresponding to the delay time of the reflected wave signal (radar reflected wave). Note that, when performing FFT processing, the beat analysis unit 208 may multiply, for example, a window function coefficient such as a Han window or a Hamming window. By using the window function coefficient, it is possible to suppress side lobes that occur around the beat frequency peak.

[0097] Here, the beat frequency response (hereinafter also referred to as "BF response") output from the beat analysis unit 208 in the zth analysis unit 206 obtained by transmitting the mth chirp pulse of the chirp signal is referred to as "RFT z (f b , m) where f b represents the beat frequency index, which corresponds to the FFT index (bin number). For example, f b =0,~,N data / 2-1, z is an integer from 1 to Na, and m is an integer from 1 to N C The beat frequency index f b The smaller the beat frequency, the smaller the delay time of the reflected wave signal (e.g., the closer the distance to the target).

[0098] Also, the beat frequency index f b is calculated by using equation (1) in the case of MNS configuration and equation (2) in the case of BMS configuration, and the distance information R(f b ) in the following. Therefore, in the following, the beat frequency index f b Let "distance index f b " The distance index is also called "R-Index."

number

number

[0099] Here, B w represents the frequency sweep bandwidth within the range gate of the chirp signal, and C 0 represents the speed of light.

[0100] The DA section 209 of the zth analysis section 206 calculates N C BF response RFT obtained by transmitting chirp pulses once z (f b , m) to perform Doppler analysis for each R-Index (for example, m = 1 to N C ).

[0101] In the following, an example of the operation of the DA unit 209 in a BMS configuration in which FDM transmission and same-frequency transmission are alternately switched every transmission cycle Tr as shown in FIG. 4 will be described.

[0102] The zth DA unit 209 is C BF response RFT obtained by transmitting chirp pulses once z (f b , m), a BF response obtained from a received signal by FDM transmission in a BMS configuration (for example, a BF response when m is an odd number) is used to perform Doppler analysis for each R-Index. For example, in the BMS configuration, the mixer unit 204 of the second radar unit 10 mixes the received signal from the first radar unit 10 by FDM transmission using the output of the VCO 303 in the MNS configuration, so that the received signal from the first radar unit 10 having the frequency difference Δfc is outside the passband of the LPF 205 of the second radar unit.

[0103] Therefore, each radar unit 10 receives reflected wave signals by each MNS configuration as reception signals by FDM transmission in the BMS configuration, and does not receive reflected wave signals by TxSig from other radar units 10 in the BMS configuration and FDM transmission.

[0104] Hereinafter, the DA section 209 (Doppler analysis section 209-1 in FIG. 3) that performs Doppler analysis using such reflected wave signals will also be referred to as the "first Doppler analysis (DA) section 209" or the "mono reception Doppler analysis (DA) section."

[0105] Furthermore, the DA unit 209 performs Doppler analysis for each R-Index using a BF response (for example, a BF response when m is an even number) obtained from a received signal by identical frequency transmission in a BMS configuration.

[0106] For example, the mixer unit 204 mixes the received signal by the same frequency transmission using the output of the VCO 303 by the same frequency transmission by the MNS configuration and the BMS configuration. Therefore, each radar unit 10 receives a signal in which the reflected wave signal by the MNS configuration and the reflected wave signal by the BMS configuration are mixed.

[0107] Hereinafter, the DA unit 209 (Doppler analysis unit 209-2 in FIG. 3) that performs Doppler analysis using such reflected wave signals will also be referred to as the "second Doppler analysis (DA) unit 209" or the "mono & multi reception Doppler analysis (DA) unit."

[0108] For example, the DA unit 209 of the q-th radar unit 10 is VFT =N c / N sw If is a power of 2, FFT processing can be applied in Doppler analysis. In this case, the FFT size of the mono reception DA unit and the mono & multi reception DA unit is N VFT The maximum DFreq without aliasing derived from the sampling theorem is ±1 / (2N sw T r ) Also, the DFreq index (also called "DF-Index") f s The DFreq interval is 1 / (N c ×T r ), and f s The range of f s = -N VFT / 2, ~, 0, ~, N VFT / 2-1.

[0109] For example, among the DA units 209 in the z-th analysis unit 206 of the q-th radar unit 10, the output VFT of the mono reception DA unit z,q Mono (f b , f s ), and the output VFT of the mono & multi reception DA section z,q Mix (f b , f s ) is shown in the following formulas (3) and (4). Note that j is an imaginary unit, z is an integer between 1 and Na(q), and q is 1, 2. The BF response output from the beat analysis unit 208 in the q-th radar unit 10 is referred to as the “RFT z,q (f b , m)" and so on.

number

number

[0110] The processing in each component of the analysis unit 206 has been described above.

[0111] In FIG. 3, the CFAR section 210 of the q-th radar section 10 may include, for example, a first CFAR section 210-q (or represented as a CFAR section 210-1-q) corresponding to an MNS configuration, and a second CFAR section 210-q (or represented as a CFAR section 210-2-q) corresponding to a mono- and multi-static configuration.

[0112] The first CFAR unit 210-q performs CFAR processing (for example, adaptive threshold determination) using the outputs from the first DA units 209 (mono reception DA units) of the first to Na(q)th analyzers 206, and obtains an R-Index (hereinafter, f bp Mono ) and DF-Index (hereafter, f sp Mono Extract the

[0113] Similarly, the second CFAR unit 210-q performs CFAR processing using the outputs from the second DA units 209 (mono and multi reception DA units) of the first to Na(q)th analyzers 206, and obtains an R-Index (hereinafter, f bp Mix ) and DF-Index (hereafter, f sp Mix (also written as f sp Mono and f sp Mix may include DF-Index for the number of Doppler multiplexes.

[0114] For example, the first CFAR unit 210-q selectively extracts local peaks of a reflected wave signal (referred to as a received signal or a reflected wave signal in an MNS configuration) by TxSig from the qth radar unit 10 in the MNS configuration, using the outputs of the first DA units 209 of the first to Na(q)th analyzers 206. For example, the first CFAR unit 210-q performs CFAR processing for adaptive threshold determination after power addition at an interval that matches the DDM interval set for TxSig from the qth radar unit 10, and bp Mono and f sp Mono and output it to first separation section 211 (an operation example will be described later).

[0115] The transmission unit of the MNS configuration in the qth radar unit 10 is the transmission unit 100 of the qth radar unit 10. Similarly, the transmission unit of the MNS configuration in the qeth radar unit 10 is the transmission unit 100 of the qeth radar unit 10. The qth radar unit 10 and the qeth radar unit 10 are different radar units, and for example, when q=1, qe=2.

[0116] Also, for example, the second CFAR unit 210-q selectively extracts local peaks of the reflected wave signal by TxSig from the qeth radar unit 10 in the BMS configuration (hereinafter referred to as the reflected wave signal in the BMS configuration) using the outputs of the second DA units 209 of the first to Na(q)th analysis units 206.

[0117] For example, the second CFAR unit 210-q performs CFAR processing for adaptive threshold determination after power addition at an interval that matches the DDM interval set in the TxSig from the qe-th radar unit 10 different from the q-th radar unit 10, and bp Mix and f sp Mix and output it to second separation section 211 (an operation example will be described later).

[0118] In addition, when the DDM interval set in the TxSig from the qe-th radar unit 10 coincides with the DDM interval set in the TxSig from the q-th radar unit 10, the reflected wave signal in the MNS configuration is also detected. In this case, for example, the second CFAR unit 210-q detects the f bp Mon and f sp Mono are also extracted (an example of the operation will be described later).

[0119] Moreover, the transmitting section of the BMS configuration in the first radar section 10 is the transmitting section 100 of the second radar section 10. Similarly, the transmitting section 100 of the BMS configuration in the second radar section 10 is the transmitting section 100 of the first radar section 10.

[0120] The separation section 211 of the qth radar unit 10 may include a first separation section 211-q (or may be referred to as a separation section 211-1) that performs Doppler multiplex separation (hereinafter also referred to as "DDM separation") processing using the outputs of the first DA section 209 and the first CFAR section 210-q, and a second separation section 211-q (or may be referred to as a separation section 211-2) that performs DDM separation processing using the outputs of the second DA section 209, the second CFAR section 210-q, and the first separation section 211.

[0121] For example, the first separator 211-q of the q-th radar unit 10 performs DDM separation of the reflected wave signal in the MNS configuration (e.g., corresponding to the first reflected wave signal) using the output of the first CFAR unit 210-q. Also, the second separator 211-q of the q-th radar unit 10 performs DDM separation of the reflected wave signal in the MNS configuration (e.g., corresponding to the second reflected wave signal) and the reflected wave signal in the BMS configuration (e.g., the third reflected wave signal) using the output of the first separator 211-q and the output of the second CFAR unit 210-q.

[0122] The first demultiplexing unit 211-q outputs, for example, information on the demultiplexed signal to the determining unit 212. The output of the first demultiplexing unit 211-q may include, for example, the output from the first DA unit 209.

[0123] Furthermore, the second separator 211-q outputs, for example, information about signals obtained by separating reflected wave signals in the MNS configuration to the determining unit 212. Furthermore, the second separator 211-q outputs, for example, information about signals obtained by separating reflected wave signals in the BMS configuration to the second angle measuring unit 213-2. Furthermore, the output of the second separator 211-q may include, for example, an output from the second DA unit 209.

[0124] The information on the separated signals may include, for example, an R-Index and a DF-Index (hereinafter, sometimes referred to as separated index information) corresponding to the separated signals. An example of the operation of the q-th separating unit 211 will be described below together with an example of the operation of the Doppler shift unit 101 and the q-th CFAR unit 210. For example, q may be 1 or 2.

[0125] The operation of the Nu-th demultiplexer 211-q is related to the operation of the DS section 101 of the transmitter 100-q. Similarly, the operation of the Nu-th CFAR section 210-q is related to the operation of the DS section 101 of the transmitter 100-q. For example, Nu may be 1 or 2.

[0126] An example of operation of the DS unit 101 will be described below, followed by an example of operation of the Nu-th CFAR unit 210-q and an example of operation of the Nu-th demultiplexing unit 211-q.

[0127] [How to set DS amount] First, an example of a method for setting the amount of DS given in DS section 101 will be described.

[0128] Each of the first to Nt(q)th DS units 101 of the qth radar unit 10 receives a chirp signal from the synchronization unit 20 and transmits a different DS amount DOP at a predetermined DDM interval Δfd(q). n In this case, the DDM interval Δfd(q) may satisfy the following setting condition (1) or (2).

[0129] Setting conditions (1): The DDM intervals between the multiple radar units 10 may be set to be the same. For example, the interval between each DS amount assigned to a TxSig transmitted from each of the multiple transmitting antennas 102 of the first radar unit 10 may be the same as the interval between each DS amount assigned to a TxSig transmitted from each of the multiple transmitting antennas 102 of the second radar unit 10 (for example, Δfd(1)=Δfd(2)).

[0130] Setting condition (2): The DDM intervals between the multiple radar units 10 may be set to different intervals. For example, the interval between each DS amount assigned to a TxSig transmitted from each of the multiple transmitting antennas 102 of the first radar unit 10 and the interval between each DS amount assigned to a TxSig transmitted from each of the multiple transmitting antennas 102 of the second radar unit 10 may be different from each other (for example, Δfd(1) ≠ Δfd(2)).

[0131] In addition, in the setting condition (2), for example, the ratio between Δfd(1) and Δfd(2) may be set so as not to match an integer. For example, of Δfd(1) and Δfd(2), the ratio of the larger DDM interval to the smaller DDM interval may be different from an integer. For example, Δfd(1) / Δfd(2) or Δfd(2) / Δfd(1) may be set so as not to match an integer (to be different from an integer).

[0132] Next, an example of setting the DDM interval Δfd(q) will be described.

[0133] Note that in the following, the number of DDMs of the q-th radar unit 10 is denoted as "N" DM (q)", and the case where N DM (q) = Nt(q) will be described, but it is not limited to this. For example, the radar unit 10 may form a transmission beam by bundling some of the plurality of transmission antennas 102 and transmit DDM. In this case, N DM (q) < Nt(q). Also, for example, the index n of the DS amount DOP n (q) represents the index of the DDM signal, and n = 1 to N DM (q) is an integer. Also, N DM (q) > 1, and q = 1 or 2. Note that when Nt(q) = 1, Doppler shift multiplexing may not be used, and the q-th radar unit 10 may not include the DS unit 101.

[0134] In the present embodiment, the modulation parameter of the chirp signal is set by the control unit 304 so that FDM transmission and the same-frequency transmission in the BMS configuration are switched every transmission period. Therefore, for example, the DS unit 101 applies a phase rotation that results in a predetermined DS amount to the chirp signal every transmission period (for example, N sw × Tr) of the chirp signal transmitted by FDM, and similarly, a phase rotation that results in a predetermined DS amount is applied to the chirp signal every transmission period (for example, N sw × Tr) of the chirp signal transmitted at the same frequency.

[0135] For example, as shown in FIGS. 4(a) and 4(b), when FDM transmission and the same-frequency transmission in the BMS configuration are alternately switched every transmission period Tr, the DS unit 101 sets N sw = 2 and applies a phase rotation that results in a predetermined DS amount.

[0136] Here, in the DA unit 209 (mono-reception DA unit or mono & multi-reception DA unit), the folding derived from the sampling theorem does not occur for the DFreq f dThe range is -1 / (2N sw T r ) ≦ f d <1 / (2N sw T r For example, DFreq f d If the range is exceeded, the DA unit 209 sw T r ) ≦ f d <1 / (2N sw T r ) range, the aliased frequency is observed. Therefore, the Doppler shift given by the DS unit 101 is set to -1 / (2N sw T r ) ≦ fd < 1 / (2N sw T r Even if you set it beyond the range of -1 / (2N sw T r ) ≦ fd < 1 / (2N sw T r ) range.

[0137] Therefore, for example, the DS unit 101 is −1 / (2N sw T r ) ≦ f d <1 / (2N sw T r ), the maximum DDM interval (e.g., represented as “Δfdmax”) for Nt(q) transmitting antennas 102 (e.g., a number equal to the number of DDMs) is Δfdmax=1 / (T r N sw Nt(q)) = 1 / (T r N sw N DM (q)). The DS unit 101 may set, for example, Δfd(1) and Δfd(2) within the range of Δfdmax. This allows the DS unit 101 to set the Doppler shift within the range of 0 to 2π, which is the phase rotation that gives the Doppler shift.

[0138] As an example, the DDM intervals of the first radar unit 10 and the second radar unit 10 may be set as shown in the following equation (5).

number

[0139] For example, δ q is a parameter that determines the DDM interval. 1 = δ 2 ≧0 and N DM (1)=N DM With this setting, the DDM intervals between the multiple radar units 10 (for example, between the first radar unit 10 and the second radar unit 10) become the same interval, and the setting condition (1) is satisfied (Δfd(1)=Δfd(2)).

[0140] Or, δ 1 , δ 2 ≧0, and N DM (1)+δ 1 ≠N DM (2)+δ 2 Also, N DM (1)+δ 1 and N DM (2)+δ 2 δ 1 and δ 2 With this setting, the DDM intervals between the multiple radar units 10 (for example, between the first radar unit 10 and the second radar unit 10) become different intervals, and the setting condition (2) is satisfied.

[0141] In addition, δ 1 and δ 2 Each of may be a positive integer or a positive real number. For example, δ 1 , and δ 2 By setting δ to a positive integer, it is possible to simplify the processing in the first CFAR unit 210 and the second CFAR unit 210, which will be described later. 1 and δ 2 In the following description, each of the above values ​​is set to zero or a positive integer, but this is not limiting and each of the above values ​​may be set to a positive real number.

[0142] In addition, when it is assumed that there are many situations in which both the radar device 1 and the target are stationary, for example, a parameter (for example, DDM interval Δfd(q) or Δfd(q)) that makes the DS amount between the first radar unit 10 and the second radar unit 10 coincide with each other is set. q ) may be set in advance so as not to include n 1 and n 2 For all of the above, the parameters may be set to satisfy the following formula (6).

number

[0143] By this setting, for example, the amount of DS DOP given to the TxSig of the first radar unit 10 n1 (1) and the amount of DS DOP given to the TxSig of the second radar unit 10 n2 (2) is set to a different value.

[0144] For example, when the radar device 1 and the target are both stationary, the Doppler component is zero. Therefore, even if the reflected wave signal by TxSig from the first radar unit 10 and the reflected wave signal by TxSig from the second radar unit 10 are included in the same R-Index, the DS amount DOP of each MIMO multiplexed transmission signal is n By setting (q) to be different, the radar device 1 can receive the two signals separately by taking advantage of the difference in the detected Doppler components.

[0145] An example of setting the DS amount will be described below.

[0146] [Example 1] Setting example 1 is a setting example of the DS amount that satisfies setting condition 1.

[0147] For example, in equation (5) into which q=1, 2 are substituted, the settings that satisfy setting condition 1 are the following conditions a and b.

[0148] Condition a) N DM (1)=N DM In case of (2): Substituting q=1,2 into equation (5), δ 1 = δ 2 By setting Δfd(1)=Δfd(2), Δfd(1)=Δfd(2) where Δ 1 , δ 2 may be an integer.

[0149] Condition b)N DM (1) ≠ N DM In case of (2): Substituting q=1,2 into equation (5), N DM (1)+δ 1 =N DM (2) +δ 2 By setting Δfd(1) = Δfd(2).

[0150] Here, δ 1 , δ 2 may be an integer.

[0151] In addition, δ in equation (5) with q = 1, 2 substituted 1 = δ 2 When setting = 0, the DFreq f observed in the DA unit 209 d Range -1 / (2N sw T r ) ≦ f d <1 / (2N sw T r ) can be maximized. Therefore, even if the Doppler spectrum has a spread, for example, when the moving speed of the target is not constant and has components such as acceleration, the effect of interference between DDM signals can be reduced. On the other hand, in this case, it becomes difficult to expand the observable DFreq using the non-uniformity of the DDM interval as disclosed in Patent Document 3, and DFreq becomes larger than -1 / (2 N sw ×T r ×N DM (1)) ≦ f d <1 / (2 N sw ×T r ×N DM (1)) The same applies to the subsequent setting conditions.

[0152] In addition, δ in equation (5) with q = 1, 2 substituted 1 = δ 2 When setting DFreq f > 0, it becomes possible to expand the observable DFreq by using the non-uniformity of the DDM interval as disclosed in Patent Document 3, and the DFreq f observed in the DA unit 209 becomes d Range -1 / (2N sw T r ) ≦ f d <1 / (2N sw T r ) the DFreq of the target can be detected. In addition, by applying the determination unit 212 described later, DFreq f d Range -1 / (2T r ) ≦ f d <1 / (2T r ) the DFreq of the target can be detected (details will be described later). The same applies to the subsequent setting conditions.

[0153] An example of the DS amount in setting example 1 will be described below.

[0154] <Settings example 1-a-1 and 2> 6 and 7 are examples of N sw =2, N DM (1)=N DM (2)=3, δ 1 = δ 2 Δfd(1)=Δfd(2)=1 / (8T r 1A shows an example of setting the Doppler shift of the first radar unit 10 ((a) of each figure) and an example of setting the Doppler shift of the second radar unit 10 ((b) of each figure) when

[0155] For example, the amount of DS DOP to be assigned to each transmitting antenna 102 (for example, Tx#1 to Tx#3) of the first radar unit 10 and the second radar unit 10 is n (q) is shown in Fig. 6, where n = 1 to 3, and q = 1, 2. The DDM interval, which is the interval of the Doppler shift assigned to each transmitting antenna, is set to Δfd(1) or an integer multiple of Δfd(1).

[0156] In the example shown in FIG. 6, all the DS amounts between the first radar section 10 and the second radar section 10 match.

[0157] 7, the DS amount to be allocated to each transmitting antenna 102 of the first radar unit 10 and the second radar unit 10 is set so that the DS amount does not match between the first radar unit 10 and the second radar unit 10 (for example, so as to satisfy the formula (6)). For example, in (a) of FIG. 7, the DS amount DOP to be allocated to each transmitting antenna 102 of the first radar unit 10 is n (1) is set in the same manner as in FIG. 6(a), and in FIG. 7(b), the amount of DS DOP allocated to each transmitting antenna 102 of the second radar unit 10 is n (2) is set to a value obtained by offsetting each of the DS amounts of the first radar unit 10 by 1 / (16Tr).

[0158] <Settings example 1-a-3 and 4> FIG. 8 shows an example of N sw =2, N DM (1)=N DM (2)=3, δ 1 = δ 2 = 2, Δfd(1) = Δfd(2) = 1 / (10T r ), Figure 9 shows an example of N sw =2, N DM (1)=N DM (2)=3, δ 1 = δ 2 = 4, Δfd(1) = Δfd(2) = 1 / (14T r 1A shows an example of setting the Doppler shift of the first radar unit 10 in the case of (a) of each figure) and an example of setting the Doppler shift of the second radar unit 10 in the case of (b) of each figure).

[0159] In FIG. 8 and FIG. 9, the Doppler shifts of the first radar unit 10 and the second radar unit 10 are set with a factor of ±1 / (2N sw×Tr) is used. This setting makes it possible to distinguish between MNS-configured received signals and BMS-configured received signals even when the MNS-configured received signals and BMS-configured received signals are mixed in the subsequent separation unit 211, thereby improving the separation performance of the radar device 1 (details will be described later).

[0160] 8 and 9, the DS amount DOP allocated to each transmitting antenna 102 of the first radar unit 10 and the second radar unit 10 is set so that the DS amounts do not match between the first radar unit 10 and the second radar unit 10. n (q) is set, where n=1 to 3, and q=1, 2. In addition, the DDM interval assigned to each transmitting antenna is set to Δfd(1) or an integer multiple of Δfd(1).

[0161] Also, in FIG. 9 (setting example 1-a-4), the setting of the Doppler shift of the first radar section 10 (e.g., Doppler peak) and the setting of the Doppler shift of the second radar section 10 (e.g., Doppler peak) are set separately so as to be united (or not mixed).

[0162] <Setting example 1-b-1> For example, N sw =2, N DM (1)=3, N DM (2)=2, δ 1 = 1, δ 2 = 2, it becomes possible to set Δfd(1) = Δfd(2) = 1 / (8Tr). Fig. 10(a) shows an example of setting the Doppler shift of the first radar unit 10, and Fig. 10(b) shows an example of setting the Doppler shift of the second radar unit 10.

[0163] In Fig. 10, the DDM interval assigned to each transmitting antenna is set to Δfd(1) or an integer multiple of Δfd(1). For example, in Fig. 10, the Doppler shift settings assigned to each transmitting antenna of the first radar unit 10 and the second radar unit 10 have different DDM numbers (N DM (1) ≠ N DM (2)), ±1 / (2Nsw 10. The Doppler shift setting in FIG. 10 can improve the separation performance in the subsequent separation unit 211 when a received signal of MNS configuration and a received signal of BMS configuration are mixed (details will be described later).

[0164] 10, the DS amounts to be assigned to the transmitting antennas 102 of the first radar unit 10 and the second radar unit 10 are set so that the DS amounts do not match between the first radar unit 10 and the second radar unit 10. For example, in (a) of FIG. 10 and (b) of FIG. 10, values ​​that satisfy formula (6) are assigned.

[0165] [Example 2] Setting example 2 is a setting example of the DS amount that satisfies setting condition 2.

[0166] For example, in equation (5) into which q=1, 2 is substituted, the setting that satisfies the setting condition 2 of the above-mentioned DDM interval Δfd(q) is the following condition a and condition b.

[0167] Condition a) N DM (1)=N DM In case of (2): δ 1 ≠δ 2 0, Δfd(1) ≠ Δfd(2). Here, δ 1 , δ 2 can be an integer. For example, δ 1 ≠δ 2 may be set to a positive integer.

[0168] Condition b)N DM (1) ≠ N DM In case of (2): δ 1 = δ 2 By setting Δfd(1) ≠ Δfd(2),

[0169] Alternatively, the setting may satisfy the following conditions:

[0170] NDM (1)+δ 1 ≠N DM (2)+δ 2 By setting Δfd(1) ≠ Δfd(2).

[0171] Here, δ 1 , δ 2 can be an integer. For example, δ 1 ≠δ 2 may be a positive integer. In this case, δ is set so that the ratio between Δfd(1) and Δfd(2) does not match an integer. 1 , δ 2 Alternatively, the DS amounts may be set so as not to match between the first radar unit 10 and the second radar unit 10, for example, to satisfy formula (6).

[0172] An example of the DS amount in setting example 2 will be described below.

[0173] <Setting example 2-a-1> FIG. 11 shows, as an example, Δfd(1)=1 / (6Tr), Δfd(2)=1 / (8Tr), N sw =2, N DM (1)=N DM (2)=2, δ 1 = 1, δ 2 11(a) shows an example of setting the Doppler shift of the first radar unit 10 when .DELTA..times ...

[0174] In the example of FIG. 11, the ratio of Δfd(1) to Δfd(2) does not match an integer, and setting condition 2 of the DDM interval Δfd(q) is satisfied.

[0175] <Setting example 2-b-1> FIG. 12 shows an example of N sw =2, N DM (1)=3, N DM (2)=4, δ 1 = δ 2 12(a) shows an example of setting the Doppler shift of the first radar unit 10 in the case of =, and FIG. 12(b) shows an example of setting the Doppler shift of the second radar unit 10 in the case of =.

[0176] In the example of FIG. 12, Δfd(1)=1 / (6Tr), Δfd(2)=1 / (8Tr), the ratio of Δfd(1) to Δfd(2) does not match an integer, and setting condition 2 of the DDM interval Δfd(q) is satisfied.

[0177] <Setting example 2-b-2> FIG. 13 shows an example of N sw =2, N DM (1)=3, N DM (2)=4, δ 1 = δ 2 13A shows an example of setting the Doppler shift of the first radar unit 10 when .DELTA..times ...

[0178] In the example of FIG. 13, Δfd(1)=1 / (8Tr) and Δfd(2)=1 / (10Tr), the ratio of Δfd(1) to Δfd(2) does not match an integer, and setting condition 2 of the DDM interval Δfd(q) is satisfied.

[0179] An example of setting the DS amount has been described above.

[0180] The DS unit 101 may, for example, use the DDM interval set as described above to set a DS amount corresponding to each transmitting antenna 102, and impart phase rotation that imparts the DS amount to the chirp signal for each transmission period.

[0181] For example, the n-th DS unit 101 of the q-th radar unit 10 outputs a different DS amount DOP for each n-th transmitting antenna 102 for the m-th chirp signal input thereto. n (q) is given by the phase rotation Φ n,q As a result, different Doppler shifts are imparted to the transmission signals transmitted from the multiple transmission antennas 102.

[0182] Here, n is an integer from 1 to Nt(q) and m is an integer from 1 to N c and q is 1 or 2.

[0183] For example, Nt(q) (e.g., Nt(q)=N DM For TxSig from the (q) transmitting antennas 102, the DS amount DOP of the DDM interval Δfd(q) is n (q) is given by the phase rotation Φ n,q (m) is expressed as the following equation (7). Also, equation (8) expresses the DS amount DOP of the DDM interval Δfd(q). n Represents (q).

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[0184] Here, Φ 0 is the initial phase, and ΔΦ 0 is the reference Doppler shift phase. α is a coefficient that offsets the DS amount of each DDM signal, and may be a real value. For example, when α=1, the DS amount of the first DDM signal is zero.

[0185] As an example, Nt(1)=Nt(2)=3, ΔΦ 0 =0, Φ 0 = 0, and δ 1 = 1, δ 2 = 2, the DDM interval is Δfd(1) = 1 / (4N sw T r ), Δfd(2)=1 / (5N sw T r ) is set. For example, the DS amount DOP corresponding to the n-th transmitting antenna 102 is set to n For example, when α=1, (q) is expressed as in the following equation (9).

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[0186] For example, for the m-th chirp signal input, a different DS amount DOP is assigned to each of the n-th (n=1, 2, 3) transmitting antennas 102. n(q) is given by the phase rotation Φ n,q (m) is expressed as the following equation (10).

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[0187] For example, when the first radar unit 10 performs DDM transmission using the number of transmitting antennas Nt=3, the first DS unit 101 in the first radar unit 10 performs a phase rotation Φ 1 for the chirp signal input from the synchronization unit 20 for each transmission period Tr, as shown in the following equation (11): 1,1 The output of the first DS section 101 is output, for example, from the first transmitting antenna 102 (Tx#1). Here, cp(t) represents a chirp signal for each transmission period.

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[0188] Also, for example, when the second radar unit 10 performs DDM transmission using the number of transmission antennas Nt=3, the first DS unit 101 in the second radar unit 10 transmits the chirp signal input from the synchronization unit 20 with a transmission period T r For each, phase rotation Φ 1,2 The output of the first DS section 101 is output from the first transmitting antenna 102 (Tx#1), ​​for example.

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[0189] An example of setting the DS amount has been described above.

[0190] Next, an example of the operation of the first CFAR unit 210, the second CFAR unit 210, the first separation unit 211, and the second separation unit 211 in the q-th radar unit 10 corresponding to the operation of the DS unit 101 described above will be described.

[0191] For example, the qth radar unit 10 separates a first reflected wave signal from a received signal in a transmission period transmitted using FDM, and separates a second reflected wave signal and a third reflected wave signal based on the first reflected wave signal from a received signal in a transmission period transmitted using the same frequency.

[0192] [Example of operation of the first CFAR unit 210] For example, the first CFAR unit 210 of the q-th radar unit 10 may perform the following operation in order to receive a reflected wave signal in FDM transmission.

[0193] For example, the first CFAR unit 210 may detect peaks by searching for a power peak that matches the DDM interval set in the TxSig of the q-th radar unit 10 for each R-Index on the power sum values ​​of the outputs from the first DA units 209 of the first to Na(q)-th analysis units 206, and performing adaptive threshold processing (CFAR processing). In peak detection, the first CFAR unit 210 performs, for example, two-dimensional CFAR processing consisting of a distance axis and a DFReq axis (corresponding to relative speed), or CFAR processing that combines one-dimensional CFAR processing (for example, the processing disclosed in Non-Patent Document 3 may be applied).

[0194] Here, for example, in the DS section 101, δ q When is set to a positive integer, the interval of the DS amount is Δfd(q) or an interval that is an integer multiple of Δfd(q). Here, q may be 1 or 2. Therefore, each signal that is subjected to DDM can be detected in the DFreq region of the output of the first DA unit 209 as if it were folded back at intervals of Δfd(q). By utilizing such a property, for example, the operation of the first CFAR unit 210 can be simplified as follows.

[0195] The first CFAR unit 210 of the qth radar unit 10 detects a Doppler peak by using a threshold value for a power sum value obtained by adding up the received power of the reflected wave signal for each range (e.g., the range of Δfd(q)) corresponding to each interval of the DS amount respectively assigned to TxSig within the DFreq range to be subjected to CFAR processing output from the first DA unit 209.

[0196] For example, the first CFAR unit 210 performs a step of dividing the outputs from the first DA units 209 of the first to Na(q)-th analysis units 206 at intervals of Δfd(q) (for example, N Δfd(q) Power value q FT(f b , f s ) is added to the power addition value PowerDDM q (f b , f sdc ) and perform CFAR processing. This type of CFAR processing is called, for example, "Doppler domain compression CFAR processing" and written as "DC-CFAR." Note that DC-CFAR is described in, for example, Patent Document 4, and a detailed description thereof will be omitted.

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[0197] where f sdc =-N VFT / 2,~,-N VFT / 2+N Δfd(q) -1, and N Δfd(q) =round(Δfd(q) / (1 / (T r N c )). Also, round(x) is an operator that rounds off a real number x to output an integer value.

[0198] As a result, the range of DFreq to be CFAR-processed in the first CFAR unit 210 is expanded to the entire range (for example, −N VFT / 2~N VFT / 2-1) 1 / (Nt(q)+δ q )=1 / (N DM (q)+δ q ), it is possible to reduce the amount of calculation required for CFAR processing.

[0199] The first CFAR unit 210 adaptively sets a threshold value, for example, and calculates f bp Mono , f sp Mono As f sdcp mono , and received power information (PowerFT q mono (f bp mono , f sdcp mono +(ndm-1)×N Δfd(q) )) to the first separation unit 211. Here, ndm=1 to N DM (q)+δ q is an integer.

[0200] [Operation example of first separation unit 211] The first separation unit 211 of the q-th radar unit 10 receives, for example, f bp mono , f sdcp mono , and based on the received power information, the following operations are performed.

[0201] <δ q If 0: In the first separation unit 211, for example, the DFreq of the target is −1 / (2T r N sw ) ≦ f d <1 / (2T r N sw ) may be assumed to be the target. Since the DFreq of the target is finally determined in the subsequent determination unit 212, the determination in the first separation unit 211 is also called a "provisional determination" or "provisional decision". DM The reception levels of (q) DF-Indexes and the top N DM DF-Index and different δ qThis may be utilized by making use of the fact that the difference between the reception levels of the DF-Indexes is large (for example, the difference is equal to or greater than a threshold). For example, first demultiplexing section 211 compares reception power information input from first CFAR section 210 to provisionally determine DFreq. Note that an example of the operation of first demultiplexing section 211 is disclosed in, for example, Patent Document 3, and therefore description of the example of the operation will be omitted here.

[0202] For example, the first separator 211 separates Δ q DF-Index and the top N with the highest received power DM Based on the relationship with the DF-Index, the DS amount of the transmitted DDM signal and f sdcp mono +(ndm-1)×N Δfd(q) The separation index information f of the DDM signal is Tx (q)=(f dmlTx#1 (q),~,f dmlTx#NDM The signal (q) is output to the second separation unit 211 and the determination unit 212.

[0203] where f dmlTx#n (q) denotes the DF-Index of the reflected wave signal by TxSig from the n-th transmitting antenna 102 (Tx#n) of the q-th radar unit 10.

[0204] Fig. 14 shows an example of an output (for example, received DFreq) of the DA unit 209 when receiving a reflected wave signal by TxSig from the first radar unit 10. In Fig. 14, the vertical axis represents the distance axis, and the horizontal axis represents the DFreq axis.

[0205] For example, in the R-Index (fb1 or fb2) shown in FIG. 14, when DFreq peak components (hereinafter referred to as DF-Peak) that coincide with an interval of Δfd(1) or an integer multiple of an interval of Δfd(1) are observed, the first separation unit 211 determines (e.g., detects) that these DFreq peak components are reflected wave signals due to TxSig from the first radar unit 10.

[0206] Also, for example, in FIG. 14, δ1 (=1) DF-Index is represented by a circle, and the top N received power is DM (=2) DF-Peaks are represented by cross and triangle marks. For example, DF-Indexes (circles) that do not match the interval of Δfd(1) are -1 / (2T r N sw ) ≦ f d <1 / (2T r N sw ), the first separation unit 211 can provisionally determine the DFreq of the target uniquely within the above range.

[0207] In addition, the first separator 211 can determine the association between the DFreq and the transmitting antenna 102, for example, based on the magnitude relationship between the DF-Index (marked with a circle) and the DF-Peak (marked with a cross) that coincides with the interval of another Δfd(1).

[0208] As an example, in FIG. 14(a), when R-Index=fb1, N DM We will explain the case where (1)=2, Tx#1 is assigned to DFreq (marked with an X) that is Δfd(1) higher than the DF-Index (marked with a circle) and TxSig is transmitted, and Tx#2 is assigned to DFreq (marked with a △) that is Δfd(1) lower than the DF-Index (marked with a circle) and TxSig is transmitted.

[0209] In this case, in FIG. 14(a), the first separator 211 separates, for example, Δ 1 By detecting DF-Indexes (marked with a circle), it can be determined that the DF-Peak (marked with an X) that is Δfd(1) higher than DFreq (marked with a circle) corresponds to Tx#1, and the DF-Peak (marked with a △) that is Δfd(1) lower than DFreq (marked with a circle) corresponds to Tx#2.

[0210] Similarly, in FIG. 14B, it is assumed that the same DDM signal allocation as in FIG. 14A is performed for R-Index=fb2. The observable DFreq range in the DA unit 209 is −1 / (2T r N sw ) ≦ f d <1 / (2T r Nsw ), for example, DFreq (marked with an x) that is higher by Δfd(1) than DF-Index (marked with a circle) is in the range of 1 / (2T r N sw ), it may be observed as aliasing in a low frequency region. Since the first separator 211 can anticipate the occurrence of aliasing in advance, it can determine, for example, that a DF-Peak (△ mark) lower than the DF-Index (◯ mark) by Δfd(1) corresponds to Tx#2, and a DF-Peak (× mark) further lower by Δfd(1) corresponds to Tx#1.

[0211] [Example of operation of the second CFAR unit 210] For example, the second CFAR unit 210 of the qth radar unit 10 may perform the following operations to receive a reflected wave signal by TxSig from the qth radar unit 10 transmitted at the same frequency in a BMS configuration, and a reflected wave signal by TxSig from the qeth radar unit 10.

[0212] Here, qe represents the radar number of a radar unit 10 different from the q-th radar unit 10. For example, in the case of the first radar unit 10 (q=1), qe=2 may be used, and in the case of the second radar unit 10 (q=2), qe=1 may be used.

[0213] <(i) When the intervals of Δfd(q) in the BMS configuration are set to the same value in the DS unit 101> The second CFAR unit 210 may detect the peaks by, for example, searching for a power peak that matches the DDM interval set in the TxSig of each of the transmission units 100 of the qth radar unit 10 and the qe radar unit 10 for each R-Index in the power sum values ​​of the outputs from the second DA units 209 of the 1st to Na(q)th analysis units 206, and performing adaptive threshold processing.

[0214] Here, for example, in the DS section 101, δ qWhen is set to a positive integer, an interval of Δfd(q) or an interval of an integer multiple of Δfd(q) is used as the interval of the DS amount (here, q may be 1 or 2, and Δfd(1)=Δfd(2)). Therefore, each signal that is subjected to DDM can be detected in the DFreq region of the output of the second DA unit 209 as if it were folded back at intervals of Δfd(q). By utilizing this property, for example, the DC-CFAR processing described in the operation of the first CFAR unit 210 can be applied. For example, the second CFAR unit 210 can perform the "VFT" in equations (13) and (14) z,q Mono (f b , f s )” is replaced with the output “VFT” from the second DA unit 209 of the first to Na(q)th analysis units 206. z,q Mix (f b , f s )" and perform DC-CFAR processing.

[0215] The following describes the subsequent operation when DC-CFAR processing is used in the CFAR unit 210. In this case, the second CFAR unit 210 adaptively sets a threshold value, for example, and selects an R-Index f bp mix , DFreq index f sdcp mix , and received power information (PowerFT q mix (f bp mix , f sdcp mix +(ndm-1)×N Δfd(q) )) to the second separation unit 211. Here, ndm=1 to N DM (q)+δ q In the following, the CFAR processing in second CFAR unit 210 described above is also referred to as "mono & multi reception CFAR".

[0216] <(ii) When the interval of Δfd(q) in the BMS configuration is set to a different value in the DS unit 101> In order to receive the reflected wave signal by TxSig from the qe-th radar unit 10, the second CFAR unit 210 converts, for example, the output VFT from the second DA unit 209 of the first to Na(q)-th analyzers 206 into z,q Mix (f b , f s ) (z=1, ∼,Na(q)), the second CFAR unit 210 may perform an operation similar to that of the first CFAR unit 210 of the qe-th radar unit 10. For example, the second CFAR unit 210 may detect a peak by searching for a power peak that matches the DDM interval Δfd(qe) set in TxSig from the qe-th radar unit 10 and performing adaptive threshold processing. Hereinafter, the CFAR processing in the second CFAR unit 210 described above is also referred to as "multiple reception CFAR".

[0217] The following describes the subsequent operation when the DC-CFAR process is used in the CFAR unit 210. The second CFAR unit 210 uses the R-Index f bp mix , DF-Index f sdcp mix , and received power information (PowerFT q mix (f bp mix , f sdcp mix +(ndm-1)×N Δfd(qe) )) to the second separation unit 211. Here, ndm=1 to N DM (qe)+δ qe is an integer.

[0218] [Operation example of second separator 211] The second separation unit 211 of the qth radar unit 10 performs DDM separation of the second reflected wave signal in the MNS configuration and the third reflected wave signal in the BMS configuration, for example, using the outputs of the first separation unit 211, the second CFAR unit 210, and the second DA unit 209.

[0219] Here, the first reflected wave signal in the MNS configuration is separated by the first separation unit 211. For this reason, the second separation unit 211 receives separation index information f Tx The output of the second DA section 209 corresponding to (q) is regarded as a second reflected wave signal, and is output to the determination section 212. Hereinafter, the output regarded as the second reflected wave signal is also referred to as the "second separation section mono received signal output."

[0220] When the center frequency of TxSig from the qth radar unit 10 in the MNS configuration (hereinafter referred to as the center frequency in the MNS configuration) differs from the center frequency of TxSig from the qth radar unit 10 in the BMS configuration (hereinafter referred to as the center frequency in the BMS configuration), the DF-Index may change depending on the relative speed of the target with respect to the radar device 1. For this reason, the second separation unit 211 regards, for example, a signal included in the change range of the DF-Index within the assumed relative speed range of the target as the second reflected wave signal, and outputs it to the determination unit 212 as the second separation unit mono received signal output.

[0221] In addition, when the second separation unit mono reception signal is output, in the DS unit 101, if the Doppler shift settings in each of the multiple radar units 10 are DS amount patterns that do not match each other even after cyclic shifting (for example, setting example 1-a-3 or setting example 1-a-4), if the number of DDMs is different (for example, setting example 1-b-1), or if the interval of Δfd(q) is set to a different value in the BMS configuration (for example, setting example 2-a-1 or setting example 2-a-2), the second separation unit 211 may determine whether or not the DS amount pattern of the Doppler shift settings in the above MNS configuration matches, whether or not the number of DDMs matches, or whether or not the interval of Δfd(q) matches. By such a determination, the second separation unit 211 can suppress the third reflected wave signal from being mistaken for the second reflected wave signal.

[0222] On the other hand, the second demultiplexing unit 211 demultiplexes the DDM signal using demultiplexing index information f TxAn output of second CFAR section 210 that does not match (or does not correspond to) (q) is output as a third reflected wave signal, and the signal after DDM separation is output to second angle measurement section 213. Hereinafter, the output thus subjected to DDM separation in second separation section 211 is also referred to as "second separation section multiple received signal output".

[0223] The latter DDM separation operation is performed, for example, by using the separation index information f Tx This is a DDM separation operation based on information input from the second CFAR unit 210 that does not match (q) (for example, can be considered as multiple reception). Therefore, the operation of second demultiplexing section 211 is the same as the operation in which information input from second CFAR section 210 that can be regarded as multiple reception is used instead of information input from first CFAR section 210 in first demultiplexing section 211. Therefore, a description of the operation of second demultiplexing section 211 will be omitted.

[0224] For example, the second separator 211 separates Δ qe DF-Index and the top N with the highest received power DM Based on the relationship with the (qe) DF-Index, the DS amount of the transmitted DDM signal and f sdcp mix +(ndm-1)×N Δfd(qe) The separation index information f of the DDM signal is Tx (qe) and output it to the second angle measuring unit 213. Here, f Tx (qe) denotes the DF-Index of the reflected wave signal by TxSig from each transmitting antenna 102 of the qe-th radar unit 10.

[0225] Furthermore, the second demultiplexing unit 211 outputs, for example, information relating to the demultiplexed second demultiplexing unit multiple reception signals to the second angle measuring unit 213. The information relating to the demultiplexed signals may include, for example, an R-Index corresponding to the demultiplexed second demultiplexing unit multiple reception signals, and demultiplexing index information of the DDM signal. The output of the second demultiplexing unit 211 may include an output from the second DA unit 209. Note that the detectable DFreq range is ±1 / (2TrN sw )

[0226] [Example of operation of determination unit 212] The determination unit 212 performs a determination of the DFreq (for example, a return determination of the DFreq) based on, for example, the first reflected wave signal and the second reflected wave signal.

[0227] For example, the determination unit 212 determines the DFreq based on the phase difference between the received signals of the second reflected wave signal in the MNS configuration separated in the first separation unit 211 and the second separation unit 211 (for example, when the "transmission condition 1" described later is satisfied) or the DFreq difference (for example, when the "transmission condition 2" described later is satisfied). This makes it possible to expand the observable DFreq range in the radar device 1 (for example, expand the DFreq range to ±1 / (2Tr)), and increase the maximum detectable DFreq. Note that the Doppler determination result obtained by expanding the observable DFreq range by the determination unit 212 may be output to, for example, the first angle measurement unit 213 together with the outputs from the first separation unit 211 and the second separation unit 211.

[0228] Transmission condition 1 and transmission condition 2 will be explained below.

[0229] <Transmission condition 1> Transmission condition 1 is the center frequency (fc mono ) and center frequency in BMS configuration (fc mix For example, transmission condition 1 is a case where the center frequency of TxSig in a transmission period in which FDM transmission is performed is the same as the center frequency of TxSig in a transmission period in which identical frequency transmission is performed.

[0230] For example, the DFreq (for example, the frequency range ±1 / (2TrN sw )) with respect to the relative velocity v of the target within the DFreq range ±1 / (2Tr) t In this case, the determination unit 212 uses the separation index information f TxThe DFreq of the target (e.g., DFreq aliasing) is determined based on the phase difference between the output of the first DA unit 209 and the output of the second DA unit 209 in (q). This makes it possible to expand the DFreq range detectable by the radar device 1 (e.g., to a frequency range of ±1 / (2Tr)).

[0231] For example, N sw In the case of =2, the frequency range corresponding to the separation index of the DDM signal output from the first separation unit 211 is ±1 / (2TrN sw ) is fd1, taking into account the DFreq aliasing in the frequency range ±1 / (2Tr), the DFreq of the target is fd1 or fd1±1 / (N sw Tr).

[0232] For example, the phase of the received signal at the DF-Index corresponding to DFreq fd1 in the first DA unit 209 and the second DA unit 209 is expressed as φ 1 (fd1) and φ 2 (fd1). For example, φ 1 (fd1) and φ 2 Phase difference of (fd1) ΔΦ(fd1)=φ 2 (fd1)-φ 1 (fd1)-2πfd1Tr is ΔΦ(fd1)=±1 / (N sw Tr)×2πTr=±(2π / N sw )=±π, DFreq wraparound occurs, and the DFreq is fd1±1 / (N sw On the other hand, if ΔΦ(fd1)=0, DFreq folding does not occur, and the DFreq is determined to be fd1.

[0233] <Transmission condition 2> Transmission condition 2 is a case where the center frequency in the MNS configuration is different from the center frequency in the BMS configuration. For example, transmission condition 2 is a case where the center frequency of TxSig in a transmission period in which FDM transmission is performed is different from the center frequency of TxSig in a transmission period in which same-frequency transmission is performed.

[0234] For example, the DFreq (for example, the frequency range ±1 / (2TrN sw )) with respect to the relative velocity v of the target within the DFreq range ±1 / (2Tr) t In this case, the determination unit 212 uses the separation index information f Tx The DFreq of the target (e.g., DFreq aliasing) is determined based on the DF-Index difference between the output of the first DA unit 209 in (q) and the output of the second DA unit 209. This makes it possible to expand the observable DFreq range in the radar device 1 (e.g., to a frequency range of ±1 / (2Tr)).

[0235] For example, the center frequency difference Δfc = (fc mono )-(fc mix ) and the relative velocity v of the target with respect to the radar device 1 t Dependent on the separation index information f Tx The operation of the determination unit 212 utilizing the change in the DF-Index information of the second DA unit 209 in response to (q) is described in, for example, JP 2023-024253 A, and therefore detailed description will be omitted. For example, the center frequency difference is set as in the following equation (15), which enables the determination unit 212 to determine the DFreq aliasing within the DFreq range ±1 / (2Tr).

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[0236] For this reason, when a Doppler peak is detected in the second DA section 209 after a predetermined number of DF-Index changes in the separation index information of the DDM signal, DFreq aliasing has occurred. Therefore, the determination section 212 determines the DFreq as one that takes DFreq aliasing into consideration according to the amount of change in the DFreq. On the other hand, when a Doppler peak is detected in the same DF-Index in the second DA section 209 in the separation index information of the DDM signal, DFreq aliasing has not occurred. Therefore, the determination section 212 determines the DFreq as one in which DFreq aliasing does not occur.

[0237] In one embodiment of the present disclosure, the transmission period Tr may be set to, for example, several hundred μs or less, and the transmission time interval of TxSig may be set to be relatively short. As a result, even if a chirp signal has a different center frequency, for example, the frequency of the beat signal of the reflected wave signal (for example, the beat frequency index) does not change, so that the radar device 1 can detect it as a change in DFreq. The transmission period Tr is not limited to the above example.

[0238] [Example of operation of first angle measuring unit 213] The first angle measuring unit 213 of the q-th radar unit 10 receives information (for example, R-Index f bp (q), and the separation index information f of the DDM signal Tx For example, the first angle measuring unit 213 may measure the angle based on the return determination of DFreq in the determination unit 212.

[0239] For example, the first angle measuring unit 213 is f bp (q) and the separation index information f of the DDM signal Tx Based on (q), the output of the DA unit 209 is extracted, and the q-th virtual receiving array correlation vector h q (f bp(q), f Tx (q)) is generated and the angle is measured, where, for example, q=1,2.

[0240] The first angle measuring unit 213 may measure the angle for each output of the first and second DA units 209, or may measure the angle using a result of combining the outputs using in-phase addition and power addition.

[0241] There are various methods for the angle measurement algorithm. For example, the estimation method disclosed in Non-Patent Document 4 may be used (the same applies to the angle measurement unit described below).

[0242] By the above operation, the first angle measuring unit 213 of the q-th radar unit 10 outputs, for example, f bp (q), Separation index information of DDM signal f Tx The angle measurement value in (q) may be output.

[0243] Also, f bp (q) may be converted into distance information using equation (1) and output.

[0244] In addition, f determined by the determination unit 212 bp The DFreq of the target in (q) may be output. Since the amount of DS assigned in the DS unit 101 at the time of transmission is known for each transmitting antenna 102, the first angle measuring unit 213 may output the DFreq of the target based on the separation index information of the DDM signal and the output of the determination unit 212.

[0245] [Example of operation of second angle measuring unit 213] The second angle measuring unit 213 of the q-th radar unit 10 receives, for example, information input from the second separation unit 211 (for example, R-Index f bp (qe), and the separation index information f of the DDM signal Tx For example, the second angle measuring unit 213 may measure the angle based on the reflected wave signal by TxSig from the qe-th radar unit 10, which is separated in the second separation unit 211.

[0246] For example, the second angle measuring unit 213 is f bp (qe) and the separation index information f of the DDM signal Tx Based on (qe), the output of the DA unit 209 is extracted, and the qe-th virtual receiving array correlation matrix H qe (f bp (qe), f Tx (qe)) is generated and the angle is measured, where, for example, qe=1,2.

[0247] The second angle measuring section 213 of the q-th radar section 10 may output, for example, the transmission azimuth direction (Direction of Departure) to the integrating section 30 as an angle measurement value (for example, positioning output).

[0248] The second angle measuring unit 213 of the q-th radar unit 10 may output the measured angle to the integrating unit 30 as a measured angle value (e.g., positioning output) of the reception azimuth direction (Direction of Arrival). For example, the measured angle may be the angle measured in the BMS configuration described in Non-Patent Document 3 or 5.

[0249] By the above operation, the second angle measuring unit 213 of the q-th radar unit 10 outputs, for example, f bp (qe), separation index information of DDM signal f Tx The transmitting azimuth angle value and the receiving azimuth angle value in (qe) may be output.

[0250] Also, f bp (qe) may be converted into distance information using equation (2) and output.

[0251] Since the amount of DS given in the DS section 101 during transmission is known for each transmitting antenna 102, the second angle measuring section 213 may output the DFreq of the target based on the separation index information of the DDM signal.

[0252] A method for estimating a target position in a radar with a BMS configuration is described in, for example, Non-Patent Document 5, so a detailed description of the estimation method will be omitted. In the above example, the angle measuring unit 213 measures the azimuth direction, but the present invention is not limited to this. Depending on the antenna arrangement of each radar, it is also possible to measure the elevation angle, or the azimuth direction and the elevation angle. For example, the angle measuring unit 213 may calculate the azimuth direction and the elevation angle direction as angle measurement values, and output the positioning.

[0253] An example of the operation of second angle measuring section 213 has been described above.

[0254] In FIG. 2, the integration unit 30 integrates the positioning outputs of the first angle measurement unit 213 and the second angle measurement unit 213 from the first radar unit 10, and the positioning outputs of the first angle measurement unit 213 and the second angle measurement unit 213 from the second radar unit 10, to perform positioning of the target.

[0255] For example, the integrating unit 30 may determine the type of target based on the coincidence between the positioning result of the second angle measuring unit 213 of the first radar unit 10 and the positioning result of the second angle measuring unit 213 of the second radar unit 10, which are positioning results of the BMS configuration. For example, the integrating unit 30 may utilize the fact that the coincidence is high for a pole (metallic pillar) and low for a target with a large width such as a wall.

[0256] Furthermore, for example, when the detection areas overlap in the positioning output of the first angle measuring unit 213 of the first radar unit 10 and the positioning output of the first angle measuring unit 213 of the second radar unit 10, which are positioning results of the MNS configuration, the integrating unit 30 may output components with high consistency between the two estimation results. For example, the integrating unit 30 may not output components with low consistency between the two estimation results. In this case, the integrating unit 30 can remove multipath reflections that become false images.

[0257] The integrator 30 may output the positioning output (or the positioning result) to, for example, a vehicle control device (such as an ECU) in the case of an on-vehicle radar, or to an infrastructure control device in the case of an infrastructure radar, both not shown.

[0258] As described above, in this embodiment, the radar device 1 includes a first radar unit 10 that transmits a first radar transmission signal and a second radar unit 10 that transmits a second radar transmission signal. Here, the multiple transmission periods in which the first radar transmission signal and the second radar transmission signal are transmitted include a transmission period in which the first radar transmission signal and the second radar transmission signal are transmitted using FDM, and a transmission period in which the first radar transmission signal and the second radar transmission signal are transmitted using the same frequency. For example, in the multiple transmission periods, the transmission period in which FDM transmission is performed and the transmission period in which the same frequency is transmitted are set alternately.

[0259] As a result, the radar device 1 alternately switches between FDM transmission and same-frequency transmission for each transmission period of the chirp signal as multiplex transmission between the BMSs, thereby maintaining radar detection performance (for example, detectable Doppler detection range) in the MNS configuration, and in addition to the MNS configuration, enables simultaneous multiplex transmission between the BMSs, thereby achieving an effect of shortening the time required for radar ranging. Therefore, according to this embodiment, the radar device 1 can efficiently detect targets.

[0260] In addition, regarding detection of DFreq in the BMS configuration in this embodiment, the Doppler detection range based on the output of the second separator 211 is ±1 / (2TrN sw ), but if the target can be regarded as the same object between the BMS configuration and the MNS configuration, the Doppler detection result in the MNS configuration may be used. As a result, in the BMS configuration, Doppler detection is performed based on the output of the determination unit 212, so the Doppler detection range can be expanded to ±1 / (2Tr).

[0261] In addition, in this embodiment, the operation of the first radar unit 10 and the second radar unit 10 has been described as an example in which the control unit 304 sets the modulation parameters of the chirp signal so that FDM transmission and same-frequency transmission are alternately switched every transmission period Tr in a BMS configuration as shown in FIG. 4, but is not limited to this.

[0262] Hereinafter, other examples (variations) of the operation of the first radar unit 10 and the second radar unit 10 in the case of using switching transmission between FDM transmission and same frequency transmission in the BMS configuration will be described. Note that, below, the operation different from the operation of the above-mentioned embodiment will be mainly described.

[0263] (Variation 1) In Variation 1, a case will be described in which, among a plurality of transmission periods in which TxSig is transmitted, a transmission period in which FDM transmission is performed is followed by a transmission period in which same frequency transmission is performed.

[0264] For example, the control unit 304 of the synchronization unit 20 detects that the same frequency transmission occurs consecutively (N sw A parameter relating to the chirp signal may be set so that the central frequency of the chirp signal varies every predetermined transmission period, so that the chirp signal is repeated 1-1) times.

[0265] FIG. 15(a) shows a case where the transmission period for switching between FDM transmission and same-frequency transmission is 3Tr (N sw 15(b) shows an example of a chirp signal in the first radar unit 10 when a transmission period in which two same-frequency transmissions are performed is set after a transmission period in which FDM transmission is performed when (f = 3). Fig. 15(b) shows an example of a chirp signal in the second radar unit 10, which has the same setting as Fig. 15(a), but differs in that chirp signals of the same center frequency are transmitted during FDM transmission and same-frequency transmission.

[0266] For example, of the three transmission cycles Tr#1 to Tr#3 shown in (a) and (b) of Fig. 15, FDM transmission is performed in the transmission cycle Tr#1, and same-frequency transmission is performed in the transmission cycles Tr#2 and Tr#3. The same is true for the three transmission cycles Tr#4 to Tr#6 shown in (a) of Fig. 15 and the subsequent transmission cycles.

[0267] As shown in Fig. 15, the same frequency transmission between BMSs (N swWhen the signal is repeated -1) times, in addition to the effects of the above embodiment, the detectable DFreq can be expanded even for inter-BMS radar reception signals.

[0268] The subsequent operations in the transmitting section 100 of the radar section 10 are similar to those in the above embodiment.

[0269] Next, an example of the operation of the receiving section 200a according to Variation 1 will be described.

[0270] In the receiving section 200a shown in FIG. 16, the DA section 209 of the z-th analyzer 206 receives the N C Using the BF response obtained by transmitting chirp pulses once, the R-Index f b Doppler analysis is performed every 10 minutes.

[0271] In the following, as shown in FIG. 15, in the BMS configuration, FDM transmission is followed by same-frequency transmission (N sw An example of the operation of DA section 209 when data is repeatedly transmitted 1) times will be described.

[0272] In this case, the DA unit 209 of the z-th analyzer 206 selects a BF response from among the BF responses obtained by transmitting the m-th chirp signal, which is a BF response from which a received signal by FDM transmission in a BMS configuration is obtained, for example, mod(m-1,N sw )=0 BF response RFT z (f b , m) to b Here, mod(x, y) is a remainder operator that outputs the remainder obtained by dividing integer x by integer y. Hereinafter, the DA unit 209 that performs the above operation is also referred to as the "first Doppler analysis unit 209 (Doppler analysis (DA) unit 209-1)" or the "mono reception Doppler analysis (DA) unit."

[0273] Furthermore, the DA unit 209 of the z-th analyzer 206 selects a BF response that can obtain a received signal by transmitting the m-th chirp signal in the BMS configuration using the same frequency transmission, for example, mod(m-1,N sw)=1,2,~,N sw BF response RFT to be -1 z (f b , m) to b The DA unit 209 that performs the above operation is referred to as the “2nd to Nth sw The second to Nth Doppler analysis units 209 are called "DA units 209". sw Each of the DA units 209 is designated as “first to (N sw -1) Mono & multi reception Doppler analysis (DA) unit.

[0274] The receiving unit 200a shown in FIG. sw 2 shows an example where m=3, and includes a first DA unit 209 which is a mono reception DA unit, and second and third DA units 209 which are first and second mono and multi reception DA units. The second DA unit 209 is a mod(m-1,N sw )=1. Similarly, the third DA unit 209 performs Doppler analysis using the BF response mod(m-1,N sw )=2, and then perform Doppler analysis.

[0275] In this way, the uDA unit 209 mod(m-1,N sw )=u-1, and then perform Doppler analysis.

[0276] Here, the output of the uDA unit 209 is expressed by the following equation (16).

number

[0277] In equation (16), VFT z,q (1) (f b , f s ) is the output of the mono receiving DA section, e.g., VFT z,q Mono(1) (f b , f s ) can also be written as

[0278] In addition, the second to Nth swThe DA section 209 is a mono and multi reception DA section, and is VFT z,q (u) (f b , f s ) is the output of the mono & multi reception DA section, for example, VFT z,q Mix(u) (f b , f s ) can also be written as

[0279] In FIG. 16, for example, the first CFAR unit 210 performs the same processing as the first CFAR unit 210 in the above embodiment.

[0280] In FIG. 16, for example, the second CFAR unit 210 receives the output (VFT) of the mono and multi reception DA unit among the DA units 209 of the first to Na(q) analyzers 206. z,q Mix(u) (f b , f s ), z=1 to Na(q)) are used to selectively extract local peaks of the third reflected wave signal. sw The local peak extraction process in the second CFAR unit 210 may be the same as that in the above embodiment. For example, the second CFAR unit 210 may use f bp Mix and DF-Index f sdcp Mix Extract the second to Nth sw It may be output to the separator 211.

[0281] 3rd~Nth sw Separation unit 211 (or separation units 211-3 to 211-N sw In the operation of the second separation unit 211 in the above-described embodiment, the output of the second DA unit 209 is divided into third to Nth sw The difference is that the output is from the DA unit 209, but other operations are similar, so a description of those operations will be omitted.

[0282] Also, No. 3 to No. N swThe separator 211, like the second separator 211, receives and separates the second reflected wave signal (for example, “third to Nth sw The first determining section 212 (also referred to as "separator mono received signal output") outputs information relating to the first determining section 212 (or determining section 212-1 or "mono received signal determining section").

[0283] In addition, the second to Nth sw The information regarding the separator mono reception signal output includes, for example, the second to Nth sw R-Index corresponding to the separation unit mono reception signal, separation index information of the DDM signal, and the second to Nth sw The output from the DA unit 209 may be included.

[0284] In addition, the second to Nth sw The separator 211 receives and separates the third reflected wave signal, and outputs the information (for example, “second to Nth sw The second to Nth received signal determination units 212-1 to 212-2 (also referred to as "separation unit multi-received signal output") are output to the second determination unit 212 (or, the determination unit 212-2 or "multiple received signal determination unit"). sw The separation unit multiple reception signal output includes the second to Nth sw The output from the DA unit 209 may be included.

[0285] In addition, the second to Nth sw The information regarding the multiple reception signal outputs of the separation unit includes, for example, the second to Nth sw R-Index corresponding to the multiple reception signals of the demultiplexer, separation index information of the DDM signal, and the second to Nth sw The output from the DA unit 209 may be included.

[0286] The first determination section 212 (or referred to as determination section 212-1) may perform the same operation as the determination section 212 in the above embodiment.

[0287] For example, the first determination unit 212 determines the first to Nth swThe DFreq is determined based on the phase difference (for example, when transmission condition 1 is satisfied) or the DFreq difference (for example, when transmission condition 2 is satisfied) of the received signal of the second reflected wave signal separated by the separation unit 211. This makes it possible to expand the observable DFreq range in the radar device 1 (receiving unit 200a) to, for example, the frequency range ±1 / (2Tr), and also to increase the maximum detectable DFreq. The Doppler determination result in which the observable DFreq range of the first determination unit 212 is expanded is the first to Nth Doppler determination results. sw It may be output, together with the input information from separation section 211, to first angle measurement section 213, for example.

[0288] Also, first determination section 212 may determine DFreq by combining the same operations as in the above embodiment with the following operations: The following combination can improve the accuracy of determining DFreq.

[0289] Alternatively, the first determination unit 212 may perform the Doppler aliasing determination by applying the following operation. In this case, the first determination unit 212 performs the Doppler aliasing determination by applying the transmission condition 2 (center frequency difference Δfc=(fc mono )-(fc mix Even if the frequency difference does not satisfy condition (1) above, it is possible to perform aliasing determination of DFreq using FDM transmission in a BMS configuration. Therefore, for example, even if the frequency band that can be assigned to the radar device 1 is narrow, the same effect as that of the above embodiment can be obtained by applying variation 1.

[0290] 2nd~Nth sw The center frequencies in the MNS configuration separated by the separation unit 211 are the same. Therefore, the first determination unit 212 determines the DFreq based on the phase difference between the received signals of the reflected wave signals by those TxSig. This makes it possible to expand the observable DFreq range in the radar device 1 (reception unit 200a) to, for example, the frequency range ±1 / (2Tr), and also to increase the maximum detectable DFreq.

[0291] 2nd~Nth sw DFreq (for example, frequency range ±1 / (2TrNsw )) for example, the relative velocity v of the target within the DFreq range ±1 / (2Tr) t In this case, the first determination unit 212 determines the second to Nth sw The second to Nth separation index information of the DDM signal output from the separation unit 211 sw DFreq may be determined based on the phase difference between the outputs of the DA unit 209. This makes it possible to expand the observable DFreq range in the radar device 1 (the receiver 200a) (for example, to a frequency range of ±1 / (2Tr)).

[0292] For example, the frequency range ±1 / (2TrN sw ) is fd1, the DFreq of the target may be fd1 or fd1±n / (NswTr) considering the DFreq aliasing in the frequency range ±1 / (2Tr) (e.g., n=1,~,NswTr). sw -1).

[0293] For example, the phase of the received signal at the DF-Index corresponding to DFreq fd1 in the second and third DA units 209 is expressed as φ 1 (fd1) and φ 2 (fd1). In this case, φ 1 (fd1) and φ 2 Phase difference of (fd1) ΔΦ(fd1)=φ 2 (fd1)-φ 1 (fd1)-2πfd1Tr is ΔΦ(fd1)=±n / (N sw Tr) × 2πTr = ±(2πn / N sw ), DFreq loopback occurs, and the first decision unit 212 sets DFreq to fd1±n / (N sw Tr). For example, N sw = 3, ΔΦ(fd1) = ±(2πn / N sw)=±2π / 3, ±4π / 3, and the first decision unit 212 decides on DFreq in the frequency range ±1 / (2Tr) based on these phases. On the other hand, when ΔΦ(fd1)=0, DFreq aliasing does not occur, and the first decision unit 212 decides that DFreq is fd1.

[0294] Note that the combination of outputs from the second and third demultiplexers 211 is not limited, and the first decision unit 212 can make a DFreq return decision based on, for example, the outputs from the n-th and n+1-th demultiplexers 211, and may make a DFreq return decision using a plurality of decision results (for example, majority decision). Here, n=1, . . ., N sw -1.

[0295] The first angle measuring unit 213, in addition to the operation of the above embodiment, for example, measures the information input from the third to the Nsw separation units 211 (for example, R-Index f bp (q), and the separation index information f of the DDM signal Tx Based on (q), the angle of the target may be measured using the second reflected wave signal.

[0296] The first angle measuring unit 213 is the third to Nth sw Angle measurement may be performed for each of the outputs of the third to NswDA units 209 input via the separation unit 211, or the angle may be measured using a result of synthesis using in-phase addition and power addition.

[0297] The second determination unit 212 (also called a “multiple received signal determination unit”) determines the second to Nth received signals. sw Since the center frequencies in the BMS configurations separated by the separation unit 211 are the same, the DFreq is determined based on the phase difference between the received signals of those reflected wave signals. This makes it possible to expand the observable DFreq range in the radar device 1 (reception unit 200a) (for example, to a frequency range of ±1 / (2Tr)), and also to increase the maximum detectable DFreq.

[0298] The operation of the second determination unit 212 is as follows: swInstead of determining DFreq based on the phase difference between the received signals of the second reflected wave signal separated in the separation unit 211, sw The difference is that DFreq is determined based on the phase difference between the received signals of the third reflected wave signal separated in separation section 211, but other operations are similar, so detailed description will be omitted.

[0299] The Doppler determination results in which the observable DFreq range is expanded in the second determination unit 212 are the second to Nth sw It may be output, together with the input information from separation section 211, to second angle measurement section 213, for example.

[0300] The second angle measuring unit 213 of the q-th radar unit 10 performs the second to N-th radar angles in addition to the operations of the above-described embodiment. sw Information input from the separation unit 211 (for example, R-Index f bp (qe), and the separation index information f of the DDM signal Tx Based on (qe), the second to Nth sw The second angle measuring unit 213 may measure the angle of the target object by using the multiple reception signal output from the separation unit. sw The second to Nth signals inputted via the separator 211 sw Angle measurement may be performed for each output of the DA unit 209, or the angle may be measured using a result of synthesis using in-phase addition and power addition.

[0301] As described above, in addition to the effects of the above-described embodiment, variation 1 has the effect of expanding the detectable DFreq for radar reception signals related to a BMS configuration.

[0302] Furthermore, in variation 1, since it is not necessary to perform DFreq determination based on the DFreq difference in the determining unit 212, it becomes possible to apply FDM transmission with a frequency difference that does not satisfy the condition of the center frequency difference Δfc in a BMS configuration. Therefore, even if the frequency band that can be assigned to the radar device 1 is narrow, by applying variation 1, it is possible to obtain the same effect as the above embodiment.

[0303] In addition, in variation 1, N sw The larger , the longer the simultaneous transmission time (the number of chirp transmissions) in the MNS configuration and the BMS configuration, and therefore the shorter the transmission time required to obtain the reception quality (e.g., SNR (Signal to Noise Ratio)) of the reflected wave signal. Also, the reception SNR of the reflected wave signal for a certain transmission time can be improved, and the detection range of the radar device 1 can be expanded.

[0304] (Variation 2) In Variation 2, a case will be described in which, in multiple transmission periods in which TxSig is transmitted, a transmission period in which FDM transmission is performed is followed by a transmission period in which same-frequency transmission is performed consecutively, as in Variation 1. In Variation 2, the center frequencies of TxSig in the multiple transmission periods in which same-frequency transmission is performed are different.

[0305] For example, the control unit 304 of the synchronization unit 20 may detect, as in the first variation, that the same frequency transmission occurs continuously (N sw In variation 2, the parameters of the chirp signal may be set so that the center frequency of the chirp signal varies every predetermined transmission period, so that the chirp signal is repeated (N −1) times. sw The center frequency of the chirp signal repeatedly transmitted 1) times may be set to a frequency that coincides with the center frequency of the chirp signal during FDM transmission, alternately or at predetermined transmission intervals.

[0306] FIG. 17 shows that in the BMS configuration, the transmission cycle in which FDM transmission and same-frequency transmission are switched is 3Tr (N sw =3), an example of a chirp signal is shown in which a transmission period in which FDM transmission is followed by a transmission period in which two same-frequency transmissions are performed.

[0307] For example, of the three transmission cycles Tr#1 to Tr#3 shown in FIG. 17, FDM transmission (for example, center frequencies fc(1) and fc(2)) is performed in transmission cycle Tr#1, same-frequency transmission is performed at center frequency fc(1) in transmission cycle Tr#2, and same-frequency transmission is performed at center frequency fc(2) in transmission cycle Tr#3. In this way, (N sw The center frequency of TxSig in each of the transmission cycles in which the same frequency transmission is performed (-1) may be any of the center frequencies set in the FDM in the transmission cycle in which FDM is performed. This also applies to the three Tr of the transmission cycles Tr#4 to Tr#6 shown in FIG. 17 and the subsequent transmission cycles.

[0308] As shown in Figure 17, the same frequency transmission (N sw When the signal is repeated -1) times, in addition to the effects of the above embodiment, the detectable DFreq can be expanded even for inter-BMS radar reception signals.

[0309] The subsequent operations in the transmitting section 100 of the radar section 10 are similar to those in the above embodiment.

[0310] Next, an example of the operation of the receiving section 200b according to Variation 2 will be described.

[0311] In the receiving unit 200b shown in FIG. 18, the DA unit 209 of the z-th analysis unit 206 receives the first to N sw The same operation as that of the DA unit 209 is performed. The BF response RFT obtained by the m-th chirp signal transmission z (f b , m), the uDA unit 209 mod(m-1,N sw )=u-1 BF response RFT z (f b , m) for Doppler analysis, where m=1,~,Nc and u=1,~,N sw In addition, the receiving unit 200b shown in FIG. sw Here is an example of =3.

[0312] Next, an example of the operation of the CFAR unit 210 shown in FIG. 18 will be described.

[0313] In FIG. 18, for example, the first CFAR unit 210 performs the same processing as the first CFAR unit 210 in the above embodiment.

[0314] 18, the second CFAR unit 210 includes an output VFT of the mono and multi reception DA unit of the DA unit 209 of the first to Na(q) analyzers 206. 1,q Mix(u) (f b , f s ), V.F.T. 2,q Mix(u) (f b , f s ), ~, VFT Na(q),q Mix(u) (f b , f s ) (e.g., u=2,~,N sw ), for example, the output of the DA unit 209 in a transmission period with a low center frequency of the chirp signal due to same-frequency transmission in the BMS configuration (for example, the transmission period of fc(1) in FIG. 17) (hereinafter, the output of the corresponding DA unit 209 is referred to as the “u low The second CFAR unit 210 receives the u-th low The local peak of the third reflected wave signal is selectively extracted using the power sum of each reception power value of the DA unit output. The local peak extraction process in the second CFAR unit 210 may be the same as that in the above embodiment. For example, the second CFAR unit 210 may use an R-Index f bp MixLow and DF-Index f sdcp MixLow Extract the first u low It may be output to the separation unit 211 (for example, the second separation unit 211 or the separation unit 211-2).

[0315] The third CFAR unit 210 receives the output VFT of the mono and multi reception DA unit among the DA units 209 of the first to Na(q) analysis units 206. 1,q Mix(u) (f b , f s ), V.F.T.2,q Mix(u) (f b , f s ), ~, VFT Na(q),q Mix(u) (f b , f s ) (e.g., u=2,~,N sw ), for example, the output of the DA unit 209 in a transmission period with a high center frequency of the chirp signal due to same-frequency transmission in the BMS configuration (for example, the transmission period of fc(2) in FIG. 17) (hereinafter, the output of the corresponding DA unit 209 is referred to as the “u hi The third CFAR unit 210 receives the Doppler analysis (DA) unit output. hi Using the power sum of each reception power value of the DA unit output, a local peak of a reflected wave signal (for example, a fourth reflected wave signal) in a BMS configuration is selectively extracted. Note that the local peak extraction process in the third CFAR unit 210 may be the same as that in the above embodiment. For example, the third CFAR unit 210 may use an R-Index f bp MixHi and DF-Index f sdcp MixHi Extract the first u hi The signal may be output to a separator 211 (for example, the third separator 211 or the separator 211-3).

[0316] 2nd~Nth sw Separation unit 211 (or separation units 211-2 to 211-N sw Of these, the uth low A separation unit 211 (hereinafter, the uth low 18, the second separator 211 performs a separation operation based on the output of the second CFAR unit 210. sw In the separation unit 211, the u-th hi A separation unit 211 (hereinafter, the uth hi18, third separation section 211) performs separation operation based on the output of third CFAR section 210. Other operations in separation section 211 are similar to those in separation section 211 in variation 1, and therefore description of those operations will be omitted.

[0317] First determination section 212 may perform the same operation as determination section 212 in the above embodiment. Also, first determination section 212 may determine DFreq by combining the following operations or the operations in the above embodiment. By using a combination of multiple operations, it is possible to improve the accuracy of DFreq determination. The Doppler determination result in which the observable DFreq range of first determination section 212 is expanded is the first to Nth Doppler determination results. sw It may be output, together with the input information from separation section 211, to first angle measurement section 213, for example.

[0318] 2nd~Nth sw The reflected wave signal in the MNS configuration separated by the separator 211 includes a component having the same center frequency as the first reflected wave signal separated by the first separator 211. low Separation unit 211 or u hi Using one of the outputs of the separator 211, the DFreq is determined based on the phase difference between the received signals of those reflected wave signals. This makes it possible to expand the observable DFreq range in the radar device 1 (the receiver 200b) (for example, to a frequency range of ±1 / (2Tr)), and also to increase the maximum detectable DFreq.

[0319] 2nd~Nth swIn the qe radar unit 10, which is separated in the separation unit 211 and has a BMS configuration, the TxSig that coincides with the center frequency of the chirp signal during FDM transmission is transmitted alternately or at a predetermined transmission cycle. Therefore, the second determination unit 212 (also called a multi-received signal determination unit) determines the DFreq based on the phase difference between the received signals of the reflected wave signals (for example, when transmission condition 1 is satisfied) or the DFreq difference (for example, when transmission condition 2 is satisfied) in the same manner as the operation of the first determination unit 212. This makes it possible to expand the observable DFreq range in the radar device 1 (receiving unit 200b) (for example, to the frequency range ±1 / (2Tr)), and also to increase the maximum detectable DFreq. The Doppler determination result in which the observable DFreq range of the second determination unit 212 is expanded is the second to Nth Doppler determination results. sw It may be output, together with the input information from separation section 211, to second angle measurement section 213, for example.

[0320] The second determination unit 212 is a second to Nth sw The DFreq is determined based on the frequency difference between the reflected wave signals in the BMS configuration separated in the separation unit 211. This operation is the same as that of the determination unit 212 in the above embodiment, and therefore a detailed description will be omitted. The Doppler determination result in which the observable DFreq range is expanded in the second determination unit 212 is the second to Nth Doppler determination results in which the observable DFreq range is expanded. sw It may be output, together with the input information from separation section 211, to second angle measurement section 213, for example.

[0321] The operations of the first and second angle measuring sections 213 shown in FIG. 18 are similar to those in Variation 1, and a description of these operations will be omitted.

[0322] As described above, in addition to the effects of the embodiment, variation 2 has the effect of expanding the detectable DFreq for radar reception signals related to a BMS configuration.

[0323] Furthermore, in Variation 2, when a chirp signal whose center frequency during same-frequency transmission is the same as that during FDM transmission is included, it is not necessary to perform DFreq determination based on the DFreq difference in the first determination unit 212, and therefore FDM transmission can be applied with a frequency difference that does not satisfy the condition of the center frequency difference Δfc in the BSM configuration. Therefore, even if the frequency band that can be assigned to the radar device 1 is narrow, by applying Variation 2, it is possible to obtain the same effect as the above embodiment.

[0324] In addition, in variation 2, N sw The larger the , the longer the time for simultaneous transmission (the number of chirp transmissions) in the MNS configuration and the BMS configuration, and therefore the shorter the transmission time for obtaining the reception quality (SNR) of the reflected wave signal. In addition, the reception SNR of the reflected wave signal for a certain transmission time can be improved, and the detection range of the radar device 1 can be expanded.

[0325] (Variation 3) In variation 3, in a plurality of transmission periods in which TxSig is transmitted, a plurality of transmission periods in which FDM transmission is performed are consecutively set, and at least one transmission period in which same frequency transmission is performed is set after the plurality of transmission periods in which FDM is performed. Also, in variation 3, for example, the center frequencies of the TxSigs in the transmission periods in which a plurality of FDM transmissions is performed are different in each of the first radar unit 10 and the second radar unit 10.

[0326] For example, the control unit 304 of the synchronization unit 20 may set the center frequency of the chirp signal by FDM transmission in the BMS configuration alternately or variably for each predetermined transmission period, and set parameters related to the chirp signal so that FDM transmission is repeated α times. In addition, the control unit 304 may set a parameter related to the chirp signal so that after α times of FDM transmission, the same frequency transmission is repeated (N sw Parameters relating to the chirp signal may be set so that the center frequency of the chirp signal varies every predetermined transmission period, so that the chirp signal is repeated (-α) times.

[0327] FIG. 19 shows that in the BMS configuration, the transmission cycle in which FDM transmission and same-frequency transmission are switched is 3Tr (N sw = 3), an example of a chirp signal when α = 2 FDM transmissions followed by one same-frequency transmission is shown.

[0328] For example, of the three Tr of transmission cycles Tr#1 to Tr#3 shown in Fig. 19, FDM transmission is performed in transmission cycle Tr#1, FDM transmission is performed by switching the center frequency of the chirp signal in transmission cycle Tr#1 between the first radar unit 10 and the second radar unit 10 in transmission cycle Tr#2, and same frequency transmission is performed in transmission cycle Tr#3. In this way, the center frequency of TxSig in each transmission cycle in which α FDM transmissions are performed may be switched between the first radar unit 10 and the second radar unit. The same applies to the three Tr of transmission cycles Tr#4 to Tr#6 shown in Fig. 19 and the subsequent transmission cycles.

[0329] As shown in FIG. 19, when the center frequency of the chirp signal by FDM transmission is set alternately and variably for each transmission period, the center frequency of the chirp signal of either the first radar unit 10 or the second radar unit 10 may match the center frequency of the chirp signal by same-frequency transmission in the BMS configuration (for example, fc(1) in FIG. 19) (hereinafter referred to as "transmission condition 3"). When transmission condition 3 is satisfied, in addition to the effects of the above-mentioned embodiment, the determination unit 212 may not need to determine DFreq based on the DFreq difference. As a result, in the BMS configuration, FDM transmission may be applied with a frequency difference that does not satisfy the condition of the center frequency difference Δfd, so that the same effects as those of the embodiment can be obtained by applying variation 3 even when the frequency band that can be assigned to the radar device 1 is narrow.

[0330] The subsequent operations in the transmitting section 100 of the radar section 10 are similar to those in the above embodiment.

[0331] Next, an example of the operation of the receiving section 200c according to the third variation will be described.

[0332] In the receiving unit 200c shown in FIG. 20, the DA unit 209 of the z-th analysis unit 206 receives the first to N sw The same operation as that of the DA unit 209 is performed. The BF response RFT obtained by the m-th chirp signal transmission z (f b , m), the uDA unit 209 mod(m-1,N sw )=u-1 BF response RFT z (f b , m) for Doppler analysis, where m=1,~,Nc and u=1,~,N sw In addition, the receiving unit 200c shown in FIG. sw Here is an example of =3.

[0333] N sw Among the DA units 209, the output of the DA unit 209 (mono reception DA unit) for the reception signal by FDM transmission in the BMS configuration is represented as VFT z,q Mono(v1) (f b , f s ) (e.g., z=1,~,N a (q)), where "v1" is N sw In the transmission period of N, the ordinal number of the transmission period for FDM transmission in the BMS configuration is represented. For example, in the example of FIG. sw In the transmission period of N = 3, FDM transmission and same frequency transmission are switched, sw Since FDM transmission is performed in the first and second transmission periods of v1=3, v1-th (v1=1,2) DA unit 209 corresponds to the mono reception DA unit.

[0334] Also, N sw The output of the DA unit 209 (mono & multi reception DA unit) for the reception signal by the same frequency transmission in the BMS configuration is called VFT z,q Mix (v2) (f b , f s ), where z=1,~,N a (q) and "v2" is N swIn the transmission period of N sw Since the same frequency is transmitted in the third transmission period of the v2=3 transmission periods, the v2-th (v2=3) DA unit 209 corresponds to the mono & multi reception DA unit.

[0335] Next, an example of the operation of the CFAR unit 210 shown in FIG. 20 will be described.

[0336] In FIG. 20, the first CFAR unit 210 receives the output VFTs of the mono reception DA units of the first to Na(q) analysis units 206. z,q Mono(v1) (f b , f s ) (e.g., z=1,~,N a 19)) in a transmission period in which the center frequency of the chirp signal due to FDM transmission in the BMS configuration is low (for example, the transmission period of fc(1) in FIG. 19) (hereinafter, “v1 low The first CFAR unit 210 receives, for example, the first Doppler analysis (DA) unit output v1 low A local peak of the reflected wave signal in the MNS configuration is selectively extracted using the power sum of each reception power value of the DA unit output. Note that the local peak extraction process in the first CFAR unit 210 may be the same as that in the above embodiment. For example, the first CFAR unit 210 may use an R-Index f bp MonoLow and DF-Index f sdcp MonoLow Extract the first v1 low It may be output to the separation unit 211 (for example, the first separation unit 211).

[0337] The second CFAR unit 210 receives the output VFT of the mono reception DA unit of the first to Na(q) analysis units 206. z,q Mono(v1) (f b , f s ) (e.g., z=1,~,N a(q)), for example, the output of the DA unit 209 in a transmission period in which the center frequency of the chirp signal by FDM transmission in the BMS configuration is high (for example, the transmission period of fc(1) in FIG. 19) (hereinafter, “v1 hi The second CFAR unit 210 receives, for example, the first hi The power sum of the reception power values ​​of the DA unit output is used to selectively extract local peaks of the reflected wave signal in the MNS configuration. The local peak extraction process in the second CFAR unit 210 may be the same as that in the above embodiment. For example, the second CFAR unit 210 may use an R-Index f bp Monohi and DF-Index f sdcp Monohi Extract the first v1 hi It may be output to the separation unit 211 (for example, the second separation unit 211).

[0338] The third CFAR unit 210 includes an output VFT of the mono and multi reception DA unit among the first to Na(q) analysis units 206. z,q Mix(v2) (f b , f s ) (e.g., z=1,~,N a (q)) is input. The third CFAR unit 210 selectively extracts local peaks of the reflected wave signal in the BMS configuration, for example, by using a power sum of each reception power value of the output of the mono & multi reception DA unit. Note that the local peak extraction process in the third CFAR unit 210 may be the same as that in the above embodiment. For example, the third CFAR unit 210 may use an R-Index f bp Mix and DF-Index f sdcp Mix and output it to the v2 separation unit 211 (for example, the third separation unit 211).

[0339] Chapter v1 low The separation unit 211 is a v1 lowThis is a separation unit that receives the DA unit output as input, and performs separation operation based on the output of the first CFAR unit 210.

[0340] Chapter v1 hi The separation unit 211 is a v1 hi This is a separation unit that receives the output of the DA unit as input, and performs separation operation based on the output of the second CFAR unit 210.

[0341] The v2 separator is a separator that receives the output of the mono & multi reception DA unit, and separates the output of the third CFAR unit 210 and the v1 low Separation part 211, v1 hi The separation operation may be performed based on the output of the separation unit 211, or the v1 low Separation part 211, v1 hi The demultiplexing operation may be performed based on the output of demultiplexing section 211 where, in the BMS configuration, the centre frequency of the chirp signal by single-frequency transmission and the centre frequency of the chirp signal by FDM transmission are the same frequency.

[0342] In addition, v1 low Separation part 211, v1 hi The separation operation in the separation unit 211 and the v2 separation unit 211 is similar to that in the separation unit 211 in the above embodiment, and therefore a description of the operation will be omitted.

[0343] Also, v1 low Separation unit 211 and v1 hi The separator 211 outputs to the determiner 212, for example, information on the received and separated reflected wave signal in the MNS configuration (also referred to as, for example, “separator mono received signal output”).

[0344] Similarly to the second separator 211 in the above embodiment, the v2 separator 211 outputs, for example, information on the reception and separation of a reflected wave signal in an MNS configuration (also referred to as "v2 separator mono received signal output") to the determination unit 212. The v2 separator 211 outputs, for example, information on the reception and separation of a reflected wave signal in a BMS configuration (also referred to as "v2 separator multi received signal output") to the second angle measurement unit 213.

[0345] In variation 3, since transmission condition 3 is satisfied, determination section 212 can perform the following operation.

[0346] For example, the determination unit 212 determines whether the first low Separation unit 211 and v1 hi For at least one of the demultiplexers 211, DFreq is determined based on the phase difference (for example, transmission condition 1) between the reflected wave signal in the MNS configuration demultiplexed in the v2 demultiplexer 211 in the BMS configuration and in the same frequency transmission.

[0347] This allows the radar device (receiving unit 200c) to expand the observable DFreq range (for example, to a frequency range of ±1 / (2Tr)), and the maximum detectable DFreq can also be increased. The Doppler determination result in which the observable DFreq range of the determining unit 212 is expanded is v1 low , No. v1 hi and the input information from the v2 separator 211 may be output to the first angle measuring unit 213, for example.

[0348] In addition to the operation of the above embodiment, the first angle measuring unit 213 of the q-th radar unit 10 may perform, for example, the v1 low , No. v1 hi and information input from the v2 separation unit 211 (for example, R-Index f bp (q), and the separation index information f of the DDM signal Tx Based on (q), the reflected wave signal in the MNS configuration is used to measure the target angle. low , No. v1 hi and the v1 input via the v2 separation unit 211 low , No. v1 hi Alternatively, the angle may be measured using a result of combining the outputs of the v2DA unit 209 using in-phase addition and power addition.

[0349] As described above, in Variation 3, in addition to the effects of the above-mentioned embodiments, it is not necessary to perform DFreq determination based on the DFreq difference in the determination unit 212, and therefore inter-BMS FDM transmission can be applied with a frequency difference that does not satisfy the condition of the center frequency difference Δfc. Therefore, even if the frequency band that can be assigned to the radar device 1 is narrow, by applying Variation 3, it is possible to obtain the same effects as those of the above-mentioned embodiments.

[0350] Note that the determination unit 212 may determine the DFreq by combining a DFreq determination based on the phase difference of the reflected wave signals (for example, transmission condition 1) with a DFreq determination based on the DFreq difference of the reflected wave signals (for example, transmission condition 2). In this case, in addition to the effects of the embodiment, it is possible to improve the determination accuracy of the determination unit 212 when the SNR of the received signal of the reflected wave signal is low.

[0351] Also, for example, it is possible to transmit a combination of variation 3 and variation 1 or 2, and the effects of each of the combined variations can be obtained.

[0352] (Variation 4) In the above embodiment, as shown in Fig. 4, in FDM transmission in a BMS configuration, the first radar unit 10 and the second radar unit 10 transmit chirp signals whose center frequencies differ by Δfd, respectively, but the FDM transmission method is not limited to this. FDM transmission can also be realized by, for example, making the transmission timings of chirp signals having the same center frequency different between the first radar unit 10 and the second radar unit 10.

[0353] Fig. 21 shows a configuration example of the synchronization unit 20a of the radar device 1 according to Variation 4. As shown in Fig. 21, the synchronization unit 20a includes a generation unit 301, a control unit 304, a delay unit 305, and a switching unit (SW) 306. Note that the configuration of the radar unit 10 may be any of the configurations in the above embodiment and Variations 1 to 3.

[0354] The synchronization unit 20a shown in FIG. 21 realizes FDM transmission by, for example, using the delay unit 305 to switch between transmission delay ON and transmission delay OFF for each transmission period.

[0355] For example, when the transmission delay is ON, the control unit 304 controls the SW306 to output a signal (path A) that has passed through the delay unit 305 that time-delays the output of the VCO 303 to the radar unit 10. On the other hand, when the transmission delay is OFF, the control unit 304 controls the SW306 to output a signal (path B) that does not pass through the delay unit 305 that time-delays the output of the VCO 303 to the radar unit 10.

[0356] As a result, when the transmission delay is ON, the radar unit 10 transmits TxSig at a delayed timing compared to the other radar units 10, and when the transmission delay is OFF, the radar unit 10 transmits TxSig at the same timing as the other radar units 10.

[0357] An example of transmitting a chirp signal according to Variation 4 is shown in FIG.

[0358] As shown in FIG. 22, in a certain transmission cycle (e.g., Tr#1, Tr#3), the transmission timing of a chirp signal with a center frequency fc(1) differs by Td between the first radar unit 10 and the second radar unit 10 (e.g., the transmission timing of the first radar unit 10 in FIG. 22(a) is delayed to the transmission timing of the second radar unit 10 in FIG. 22(b)). As a result, a frequency difference of Dm×Td occurs at the same time between the transmission frequency of the chirp signal of the qth radar unit 10 and the transmission frequency of the chirp signal of the qeth radar unit 10, and therefore an effect equivalent to that obtained when the center frequency difference Δfd is set to Dm×Td can be obtained. Here, D m is the frequency sweep rate of the chirp signal.

[0359] When the output of the mixer unit 204 is passed through the LPF 205, in order to block the reflected wave signal in the BMS configuration, Td may be adjusted so that the reflected wave signal in the BMS configuration is outside the frequency passband of the LPF 205. This enables FDM transmission. For example, when the maximum distance of the assumed target is Rmax, the minimum Td-2Rmax / C 0 Therefore, the cutoff frequency f cutoff Dm × (Td-2Rmax / C 0 )>f LPF_cutoff As a result, the reflected wave signal in the BMS configuration is outside the frequency passband of the LPF 205, making FDM transmission possible.

[0360] In addition, in response to the transmission timing of the chirp signal having the center frequency fc(1) being made different (shifted) by Td between the first radar unit 10 and the second radar unit 10, the timing of the range gate Tsw when transmitting the chirp signal transmitted by FDM may be made different by Td from the timing of the range gate Tsw when transmitting a chirp signal transmitted at the same frequency. In this way, the radar device 1 obtains a received signal in which the center frequency of the chirp signal is the same when transmitting the chirp signal transmitted by FDM and when transmitting the chirp signal transmitted at the same frequency.

[0361] In variation 4, each chirp signal is transmitted at the same center frequency, so that the operation of determining DFreq aliasing in determining section 212 can be determined based on the phase difference in transmission condition 1. Therefore, even if the center frequency difference Δfd=Dm×Td does not satisfy the frequency condition in the above embodiment, the effect of detectable DFreq expansion can be obtained in the same way as in the above embodiment.

[0362] As described above, in addition to the effects of the above-mentioned embodiments, variation 4 does not require DFreq judgment based on the DFreq difference in judgment unit 212, and even if the frequency band that can be assigned to radar device 1 is narrow, by applying variation 4, it is possible to obtain the same effects as those of the above-mentioned embodiments.

[0363] In addition, since FDM transmission in a BMS configuration can be realized by using the delay unit 305 that imparts a transmission delay in the synchronization unit 20a, for example, the radar device 1 does not need to include multiple VCOs 303 or a VCO frequency conversion unit that frequency converts the output of the VCO 303, and the circuit configuration of the radar device 1 can be further simplified.

[0364] Moreover, variation 4 is not limited to the above embodiment, and can be similarly applied to any of variations 1 to 3. For example, instead of the inter-BMS FDM transmission in variations 1 to 3, the radar device 1 transmits chirp signals having the same center frequency at different transmission timings from the first radar unit 10 and the second radar unit 10. This provides the effects described in variation 4 in addition to the effects of variations 1 to 3.

[0365] (Variation 5) In the above embodiment, as shown in Fig. 4, in the same frequency transmission in the BMS configuration, the first radar unit 10 and the second radar unit 10 transmit chirp signals at the same timing, but the same frequency transmission is not limited to this. For example, the same effect can be obtained even when the same chirp signal is transmitted between the first radar unit 10 and the second radar unit 10 with the transmission timing of the chirp signal being made different (or shifted).

[0366] An example of transmitting a chirp signal according to Variation 5 is shown in FIG.

[0367] As shown in Fig. 23, in a certain transmission cycle (e.g., Tr#2, Tr#4), the transmission timing of a chirp signal with a center frequency fc(1) differs by Tdmix between the first radar unit 10 in Fig. 23(a) and the second radar unit 10 in Fig. 23(b) (e.g., the transmission timing of the first radar unit 10 is delayed). Note that the setting of the transmission timing of the chirp signal during same-frequency transmission (e.g., setting of the delay) may be performed using the same operation as that of the setting of the transmission timing of the chirp signal during FDM transmission in variation 4 (e.g., operation by the synchronization unit 20a shown in Fig. 21).

[0368] For example, when the output of the mixer unit 204 passes through the LPF 205, Tdmix may be adjusted to be within the frequency passband of the LPF 205 so as to receive (or pass) the reflected wave signal in the BMS configuration. For example, if the maximum distance of the assumed target is Rmax, then maximum Tdmix+2Rmax / C 0 Therefore, the cutoff frequency f cutoff For Dm × (Tdmix + 2Rmax / C 0 ) <f LPF_cutoff By doing so, it is possible to receive the reflected wave signal in the BMS configuration. Also, by setting such Tdmix, it is possible to relatively shift the reception time of the reflected wave signal in the BMS configuration from the reception time of the reflected wave signal by TxSig from the own radar in the BMS configuration.

[0369] For example, in the case where reflected wave signals in a short distance range arrive closely from both the radar itself and other radars, the radar device 1 sets Tdmix to relatively shift the reception times, thereby obtaining an effect of facilitating separation of mono / multi signals in the second separation unit 211 in the above embodiment. Note that variation 5 is not limited to the above embodiment, and can be similarly applied to any of variations 1 to 4, and similar effects can be obtained.

[0370] (Variation 6) In the above embodiment, the BMS configuration including the first radar unit 10 and the second radar unit 10 has been described, but the present invention is not limited to this. For example, the BMS configuration may use two or more radar units 10, and the same effects as those of the above embodiment can be obtained. Similarly, for variations 1 to 5, for example, two or more radar units 10 may be used, and the same effects as those of each variation can be obtained.

[0371] For example, when three radar units 10 are used and applied to the above embodiment, the operation is as follows.

[0372] The control unit 304 sets modulation parameters of the chirp signal so that, in an inter-BMS radar configuration, FDM transmission and same-frequency transmission are alternately switched for each transmission cycle Tr.

[0373] In this case, in FDM transmission in the BMS configuration, chirp signals with center frequencies different from each other by Δfd or more are transmitted between the three radar units 10. Also, in identical frequency transmission in the BMS configuration, the same chirp signal is transmitted between the three radar units 10. In this case, two other radar units 10 different from each radar unit 10 are included. Therefore, for example, the DDM signals provided in the DS unit 101 of each radar unit 10 may be different from each other. For example, by providing a multiplexed signal such that the number of DDMs and the DDM intervals in each radar unit 10 are different, even when a plurality of other radar units 10 different from each radar unit 10 are included, the separation unit 211 can distinguish and receive the reflected wave signals by TxSig from each radar unit 10.

[0374] Furthermore, for example, in variation 4, when three radar units 10 are applied, the control unit 304 sets the modulation parameters of the chirp signal so that FDM transmission in the BMS configuration and same-frequency transmission are alternately switched for each transmission cycle Tr. In this case, in FDM transmission in the BMS configuration, chirp signals having center frequencies that differ from each other by Δfd or more are transmitted between the three radar units 10. In same-frequency transmission in the inter-BMS radar configuration, the same chirp signal is transmitted between the three radar units 10.

[0375] 24, the transmission timing of a chirp signal with a center frequency fc(1) is made different (shifted) by Td1 or Td2 between the first radar unit 10, the second radar unit 10, and the third radar unit 10. As a result, the transmission frequency of the chirp signal of the qeth radar unit 10 has a frequency difference of ±Dm×Td1, ±Dm×Td2, or ±Dm×(Td1-Td2) with respect to the transmission frequency of the chirp signal of the qth radar unit 10 at the same time, and therefore an effect equivalent to that obtained when the center frequency difference Δfd is made different can be obtained.

[0376] At this time, when the output of mixer unit 204 in receiving radio unit 203 is passed through LPF 205, Td1 or Td2 may be adjusted so that the reflected wave signal in the BMS configuration is blocked and the reflected wave signal in the BMS configuration is outside the frequency passband of LPF 205. This enables FDM transmission.

[0377] In this case, since two other radar units 10 different from each radar unit 10 are included, for example, the DDM signals provided in the DS units 101 of each radar unit 10 may be different from each other. For example, by providing a multiplexed signal so that the number of DDMs and the DDM intervals of each radar unit 10 are different, even when a plurality of other radar units 10 different from each radar unit 10 are included, the separation unit 211 can distinguish and receive the reflected wave signals by the TxSig of each radar unit 10.

[0378] An embodiment of the present disclosure has been described above.

[0379] [Other embodiments] In the above-mentioned embodiments, the configuration using a chirp signal as TxSig has been described, but a signal other than the chirp signal may be used. For example, TxSig may be a pulse compression wave such as a coded pulse signal. When a coded pulse signal is used for TxSig, the mixer unit 204 of the receiving radio unit 203 converts a high-frequency received signal into a baseband signal, and by using a correlator (not shown) that correlates with the coded pulse signal to be transmitted instead of the beat analysis unit 208, the subsequent processing can be performed in the same manner as the processing according to the above-mentioned embodiments, and the same effects can be obtained.

[0380] In the radar device according to the embodiment of the present disclosure, the transmitter and the receiver may be disposed separately in physically separate locations. Also, in the receiver according to the embodiment of the present disclosure, the angle measuring unit and other components may be disposed separately in physically separate locations.

[0381] In addition, in one embodiment of the present disclosure, for example, the number of transmitting antennas, the number of receiving antennas, the number of DDMs, the number of radar units, the DDM interval, and a parameter related to the DDM interval (for example, δ q ), parameters related to the transmission period (e.g., N sw ) are merely examples and are not intended to be limiting.

[0382] Although not shown, the radar device according to an embodiment of the present disclosure includes, for example, a central processing unit (CPU), a storage medium such as a read only memory (ROM) storing a control program, and a working memory such as a random access memory (RAM). In this case, the functions of each of the above-mentioned units are realized by the CPU executing the control program. However, the hardware configuration of the radar device is not limited to this example. For example, each functional unit of the radar device may be realized as an integrated circuit (IC). Each functional unit may be individually implemented as a single chip, or may be implemented as a single chip that includes some or all of the functional units.

[0383] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can come up with various modified or amended examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure. In addition, the components in the above embodiments may be arbitrarily combined within the scope of the disclosure.

[0384] In addition, the notation "... part" in the above-mentioned embodiments may be replaced with other notations such as "... circuitry", "... assembly", "... device", "... unit", or "... module".

[0385] In each of the above embodiments, the present disclosure has been described as an example configured using hardware, but the present disclosure can also be realized by software in cooperation with hardware.

[0386] Moreover, each functional block used in the description of each of the above embodiments is typically realized as an LSI, which is an integrated circuit. The integrated circuit may control each functional block used in the description of the above embodiments and may have input terminals and output terminals. These may be individually integrated into one chip, or may be integrated into one chip that includes some or all of them. Here, the term LSI is used, but depending on the degree of integration, it may also be called an IC, a system LSI, a super LSI, or an ultra LSI.

[0387] The method of integration is not limited to LSI, but may be realized using a dedicated circuit or a general-purpose processor and memory. After LSI manufacture, a field programmable gate array (FPGA) that can be programmed, or a reconfigurable processor that can reconfigure the connections or settings of circuit cells inside the LSI may be used.

[0388] Furthermore, if a new integrated circuit technology that can replace LSI appears due to the progress of semiconductor technology or a derivative technology, it is possible to integrate the functional blocks using that technology. The application of biotechnology is also a possibility.

[0389] <Summary of this disclosure> A radar device according to one non-limiting embodiment of the present disclosure includes a first radar circuit that transmits a first transmission signal and a second radar circuit that transmits a second transmission signal, and a plurality of transmission periods in which the first transmission signal and the second transmission signal are transmitted include a first transmission period in which the first transmission signal and the second transmission signal are frequency division multiplexed and a second transmission period in which the first transmission signal and the second transmission signal are transmitted at the same frequency.

[0390] In one non-limiting embodiment of the present disclosure, the first transmission period and the second transmission period are set alternately in the plurality of transmission periods.

[0391] In one non-limiting embodiment of the present disclosure, in the plurality of transmission periods, a plurality of consecutive second transmission periods are set after the first transmission period.

[0392] In one non-limiting embodiment of the present disclosure, the center frequency of the transmission signal in each of the second transmission periods is different.

[0393] In one non-limiting embodiment of the present disclosure, a center frequency of a transmission signal in each of the plurality of second transmission periods is the same as one of the center frequencies set for the frequency division multiplexing transmission in the first transmission period.

[0394] In one non-limiting embodiment of the present disclosure, in the plurality of transmission periods, a plurality of consecutive first transmission periods are set, at least one of the second transmission periods is set after the plurality of first transmission periods, and a center frequency of each transmission signal in the plurality of first transmission periods is different in each of the first radar circuit and the second radar circuit.

[0395] In one non-limiting embodiment of the present disclosure, in at least one of the first radar circuit and the second radar circuit, a center frequency of a transmission signal in at least one of the plurality of first transmission periods is the same as a center frequency of a transmission signal in the second transmission period.

[0396] In one non-limiting embodiment of the present disclosure, in at least one of the first transmission period and the second transmission period, a transmission timing of the first transmission signal and a transmission timing of the second transmission signal are different.

[0397] In one non-limiting example of the present disclosure, the first radar circuit transmits the first transmission signals from a plurality of first transmission antennas, and the second radar circuit transmits the second transmission signals from a plurality of second transmission antennas, and a pattern of Doppler shift amounts imparted to the first transmission signals transmitted from each of the plurality of first transmission antennas is different from a pattern of Doppler shift amounts imparted to the second transmission signals transmitted from each of the plurality of second transmission antennas.

[0398] In one non-limiting example of the present disclosure, one of the first radar circuit and the second radar circuit separates, from the received signal in the first transmission cycle, a first reflected wave signal corresponding to the transmission signal out of the first transmission signal and the second transmission signal transmitted from the one radar circuit, and separates, from the received signal in the second transmission cycle, based on the first reflected wave signal, a second reflected wave signal corresponding to the transmission signal transmitted from the one radar circuit and a third reflected wave signal corresponding to the transmission signal out of the first transmission signal and the second transmission signal transmitted from the other radar circuit, determines aliasing of Doppler frequency based on the first reflected wave signal and the second reflected wave signal, performs a first angle measurement based on the determination of aliasing, and performs a second angle measurement based on the third reflected wave signal.

[0399] In a non-limiting embodiment of the present disclosure, of the first radar circuit and the second radar circuit, the radar circuit in which the center frequency of the transmission signal is the same in the first transmission period and the second transmission period determines the aliasing based on the phase difference between the first reflected wave signal and the second reflected wave signal.

[0400] In a non-limiting embodiment of the present disclosure, of the first radar circuit and the second radar circuit, the radar circuit in which the center frequency of the transmission signal differs between the first transmission period and the second transmission period determines the aliasing based on the difference in Doppler frequency between the first reflected wave signal and the second reflected wave signal.

[0401] In one non-limiting example of the present disclosure, in the plurality of transmission periods, a plurality of consecutive second transmission periods are set after the first transmission period, and the first radar circuit and the second radar circuit determine the folding back based on a phase difference between the second reflected wave signals of the plurality of second transmission periods and determine the folding back based on a phase difference between the third reflected wave signals of the plurality of second transmission periods.

[0402] In one non-limiting embodiment of the present disclosure, a plurality of consecutive first transmission periods are set in the plurality of transmission periods, and at least one of the second transmission periods is set after the plurality of first transmission periods, and the first radar circuit and the second radar circuit determine the return based on a phase difference between the first reflected wave signal and the third reflected wave signal in a transmission period among the plurality of first transmission periods, the transmission period having a center frequency set to the same as a center frequency of the transmission signal in the second transmission period.

[0403] A transmission method according to one non-limiting embodiment of the present disclosure is a transmission method for a radar device including a first radar circuit that transmits a first transmission signal and a second radar circuit that transmits a second transmission signal, wherein a plurality of transmission periods in which the first transmission signal and the second transmission signal are transmitted include a first transmission period in which the first transmission signal and the second transmission signal are frequency division multiplexed and a second transmission period in which the first transmission signal and the second transmission signal are transmitted at the same frequency. [Industrial Applicability]

[0404] The present disclosure is suitable for a radar device that detects a wide angle range. [Explanation of symbols]

[0405] 1. Radar equipment 10 Radar section 20,20a Synchronous section 30 Integration Department 100 Transmitter 101 Doppler shift section 102 Transmitting Antenna 200,200a Receiver 201 System Processing Unit 202 Receiving antenna 203 Receiving Radio Unit 204 Mixer section 205 LPF 206 Analysis Department 207 A / D conversion section 208 Beat Analysis Section 209 Doppler Analysis Unit 210 CFAR Department 211 Separation section 212 Judgment section 213 Angle measurement section 301 Generation part 302 Modulation signal generator 303 VCO 304 Control Unit 305 Delay Section 306 Switching section

Claims

1. A first radar circuit that transmits a first transmission signal, A second radar circuit that transmits a second transmission signal, It is equipped with, The plurality of transmission cycles in which the first transmission signal and the second transmission signal are transmitted include a first transmission cycle in which the first transmission signal and the second transmission signal are transmitted by frequency division multiplexing, and a second transmission cycle in which the first transmission signal and the second transmission signal are transmitted at the same frequency. Radar device.

2. In the plurality of transmission cycles, the first transmission cycle and the second transmission cycle are set alternately. The radar device according to claim 1.

3. In the plurality of transmission cycles, a plurality of consecutive second transmission cycles are set after the first transmission cycle. The radar device according to claim 1.

4. The center frequency of the transmitted signal in each of the aforementioned multiple second transmission cycles is different. The radar device according to claim 3.

5. The center frequency of the transmitted signal in each of the plurality of second transmission cycles is the same as any of the center frequencies set for the frequency division multiplexing transmission in the first transmission cycle. The radar device according to claim 4.

6. In the plurality of transmission cycles, a plurality of consecutive first transmission cycles are set, and after the plurality of first transmission cycles, at least one second transmission cycle is set. In each of the first radar circuit and the second radar circuit, the center frequencies of the transmission signals for each of the plurality of first transmission cycles are different. The radar device according to claim 1.

7. In at least one of the first radar circuit and the second radar circuit, the center frequency of the transmitted signal in at least one of the plurality of first transmission cycles is the same as the center frequency of the transmitted signal in the second transmission cycle. The radar device according to claim 6.

8. In at least one of the first transmission cycle and the second transmission cycle, the first transmission signal transmission timing and the second transmission signal transmission timing are different. The radar device according to claim 1.

9. The first radar circuit transmits the first transmission signal from a plurality of first transmitting antennas. The second radar circuit transmits the second transmission signal from a plurality of second transmitting antennas. The pattern of each Doppler shift amount applied to the first transmission signal transmitted from each of the plurality of first transmitting antennas is different from the pattern of each Doppler shift amount applied to the second transmission signal transmitted from each of the plurality of second transmitting antennas. The radar device according to claim 1.

10. One of the first radar circuit and the second radar circuit is: From the received signal in the first transmission cycle, the first reflected wave signal corresponding to the transmission signal transmitted from one of the radar circuits among the first transmission signal and the second transmission signal is separated. From the received signal in the second transmission cycle, a second reflected wave signal corresponding to the transmission signal transmitted from one of the radar circuits, and a third reflected wave signal corresponding to the transmission signal transmitted from the other radar circuit, based on the first reflected wave signal, are separated. Based on the first reflected wave signal and the second reflected wave signal, the Doppler frequency aliasing is determined. Based on the aforementioned determination of the return, perform the first angle measurement, A second angle measurement is performed based on the third reflected wave signal. The radar device according to claim 1.

11. Of the first radar circuit and the second radar circuit, the radar circuit in which the center frequency of the transmitted signal is the same for the first transmission period and the second transmission period determines the aliasing based on the phase difference between the first reflected wave signal and the second reflected wave signal. The radar device according to claim 10.

12. Of the first radar circuit and the second radar circuit, the radar circuit in which the center frequency of the transmitted signal differs between the first transmission period and the second transmission period determines the aliasing based on the difference in Doppler frequencies between the first reflected wave signal and the second reflected wave signal. The radar device according to claim 10.

13. In the plurality of transmission cycles, a plurality of consecutive second transmission cycles are set after the first transmission cycle. The first radar circuit and the second radar circuit are, Based on the phase difference between the second reflected wave signals of each of the plurality of second transmission cycles, the aliasing is determined. Based on the phase difference between the third reflected wave signals of each of the plurality of second transmission cycles, the aliasing is determined. The radar device according to claim 10.

14. In the plurality of transmission cycles, a plurality of consecutive first transmission cycles are set, and after the plurality of first transmission cycles, at least one second transmission cycle is set. The first radar circuit and the second radar circuit are, Based on the phase difference between the first reflected wave signal and the third reflected wave signal, the aliasing is determined based on the phase difference between the first reflected wave signal of a transmission period in which the same center frequency as the center frequency of the transmission signal of the second transmission period is set among the plurality of first transmission periods. The radar device according to claim 10.

15. A radar signal generation circuit that generates a first transmission signal transmitted from a first radar circuit and a second transmission signal transmitted from a second radar circuit, The plurality of transmission cycles in which the first transmission signal and the second transmission signal are transmitted include a first transmission cycle in which the first transmission signal and the second transmission signal are transmitted by frequency division multiplexing, and a second transmission cycle in which the first transmission signal and the second transmission signal are transmitted at the same frequency. Radar signal generation circuit.

16. In the plurality of transmission cycles, the first transmission cycle and the second transmission cycle are set alternately. The radar signal generation circuit according to claim 15.

17. In the plurality of transmission cycles, a plurality of consecutive second transmission cycles are set after the first transmission cycle. The radar signal generation circuit according to claim 15.

18. A first radar circuit that transmits a first transmission signal, A second radar circuit that transmits a second transmission signal, A transmission method for a radar device comprising, The plurality of transmission cycles in which the first transmission signal and the second transmission signal are transmitted include a first transmission cycle in which the first transmission signal and the second transmission signal are transmitted by frequency division multiplexing, and a second transmission cycle in which the first transmission signal and the second transmission signal are transmitted at the same frequency. The method of transmitting data using radar equipment.

19. In the plurality of transmission cycles, the first transmission cycle and the second transmission cycle are set alternately. A method for transmitting data using a radar device as described in claim 18.

20. In the plurality of transmission cycles, a plurality of consecutive second transmission cycles are set after the first transmission cycle. A method for transmitting data using a radar device as described in claim 18.

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