A signal sending method, a receiving method and corresponding apparatuses

Abstract

A signal sending method and receiving method and corresponding devices are used for automatic driving or assisted driving. In a signal transmitting stage, a radar can transmit a signal with a designed waveform, for example, a first frequency-modulated continuous wave sequence is generated and transmitted, wherein the first frequency-modulated continuous wave sequence includes N frequency-modulated continuous waves, N is an integer greater than or equal to 1, and the product of the time domain position and the corresponding frequency domain position in the first frequency-modulated continuous wave in the N frequency-modulated continuous waves satisfies a first condition. In this way, in a signal receiving stage, the radar can use a simple digital signal processing method (such as FFT) for signal processing to realize target speed measurement. The present application can reduce the probability of radar mutual interference while ensuring the speed measurement performance of the radar.

Description

Technical Field

[0001] This application relates to the field of sensors, and more particularly to a signal transmission method, a signal reception method, and a corresponding device. Background Technology

[0002] With societal development, intelligent vehicles are gradually becoming a part of people's daily lives. Various types of radar installed on vehicles (i.e., onboard radar), such as millimeter-wave radar, lidar, or ultrasonic radar, can continuously perceive the surrounding environment and collect data while the vehicle is in motion. This enables the identification and tracking of moving objects, the recognition of stationary scenes (such as lane lines and signs), and route planning in conjunction with navigation and map data, effectively increasing driving safety and comfort.

[0003] With the widespread use of vehicle-mounted radar, mutual interference between these radars is becoming increasingly serious. Mutual interference reduces the detection probability of vehicle-mounted radar or increases its false alarm probability, causing a significant impact on vehicle driving safety and comfort. Therefore, reducing interference between vehicle-mounted radars is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] This application provides a signal transmission method, a signal reception method, and a corresponding device, which can reduce interference between vehicle-mounted radars while ensuring the speed measurement performance of the radar.

[0005] In a first aspect, a signal transmission method is provided. This method can be executed by a first device, such as a radar, or the first device can be a chip installed in a communication device, such as a radar, or other devices, without limitation. The method includes: generating a first frequency-modulated continuous wave sequence; transmitting the first frequency-modulated continuous wave sequence, the first frequency-modulated continuous wave sequence including N frequency-modulated continuous waves, where N is an integer greater than or equal to 1; wherein the product of the time-domain position and the corresponding frequency-domain position within the first frequency-modulated continuous wave in the N frequency-modulated continuous waves satisfies a first condition.

[0006] In the above scheme, during the signal transmission phase, the first device transmits a signal using a pre-designed waveform (e.g., the product of the time-domain position and the corresponding frequency-domain position within the first frequency-modulated continuous wave in N frequency-modulated continuous waves satisfies a first condition). This allows the receiving device (e.g., the second device) to obtain the signal waveform transmitted by the first device during the subsequent signal reception phase (e.g., determining the time-domain or frequency-domain position of the first frequency-modulated continuous wave based on the first condition). This enables the use of simple digital signal processing methods (e.g., FFT) for speed measurement, improving processing efficiency. For scenarios with multiple radars, each radar can use this method to transmit signals. In practical implementation, it is only necessary to ensure that the frequency-domain positions corresponding to the signal waveforms of different radars are different at the same time-domain position (i.e., avoiding frequency-domain resource conflicts between different radars at the same time). This reduces or even eliminates mutual interference between radars. Furthermore, since each radar transmits a signal using a pre-designed waveform, the receiving device for each radar can use simple digital signal processing methods (e.g., FFT) for speed measurement, improving processing efficiency. Therefore, it is possible to reduce the probability of radar mutual interference while ensuring the radar's speed measurement performance.

[0007] In one possible design, the first condition relates to the position of the first frequency-modulated continuous wave within the N frequency-modulated continuous waves. Furthermore, for each of the N frequency-modulated continuous waves, the product of its time-domain position and its corresponding frequency-domain position can satisfy certain conditions. These conditions can differ for different frequency-modulated continuous waves, and the conditions satisfied by the product of the time-domain position and its corresponding frequency-domain position for each frequency-modulated continuous wave can be related to its position within the N frequency-modulated continuous waves.

[0008] This design method allows us to determine the time-domain and frequency-domain positions of the first frequency-modulated continuous wave based on its position within N frequency-modulated continuous waves.

[0009] In one possible design, the frequency domain position includes the starting frequency and / or the center frequency. It should be understood that the frequency domain position is a reference frequency point used by the radar to perform frequency hopping. The reference frequency points for frequency hopping in each frequency-modulated continuous wave (FMMC) wave in the first FMMC continuous wave sequence must use the same reference standard. For example, the first FMMC continuous wave sequence includes a first FMMC continuous wave and a second FMMC continuous wave, where the frequency domain position of the first FMMC continuous wave is its starting frequency, and the frequency domain position of the second FMMC continuous wave is also its starting frequency; or the frequency domain position of the first FMMC continuous wave is its center frequency, and the frequency domain position of the second FMMC continuous wave is also its center frequency.

[0010] Of course, in practical applications, the frequency domain location can also be other reference frequency points uniformly set within the frequency domain range of each frequency-modulated continuous wave, and this application does not impose any restrictions on this.

[0011] In one possible design, the time-domain position includes the start time and / or center time. It is understood that the time-domain position and the frequency-domain position can have a corresponding relationship; for example, if the frequency-domain position of the first FM continuous wave is its start frequency, then the time-domain position of the first FM continuous wave is its start time.

[0012] Of course, in practical applications, the time domain position can also be any other time position uniformly set within the time domain range of each frequency modulation continuous wave, and this application does not impose any restrictions on this.

[0013] In one possible design, the first condition may include:

[0014] ;

[0015] Where n is the index of the frequency-modulated continuous wave in the N frequency-modulated continuous waves. ; Let n be the time-domain position of the frequency-modulated continuous wave with index n among N frequency-modulated continuous waves; Let n be the frequency domain position of the frequency-modulated continuous wave with index n among N frequency-modulated continuous waves; , These are the preset frequency hopping parameters.

[0016] Understandably, in practical applications, the above formula may have other variations.

[0017] For example:

[0018]

[0019] in, The time deviation is caused by errors during product realization; when n takes different values... .

[0020] For example:

[0021]

[0022] in, The time deviation is caused by errors during product realization, and n takes different values. .

[0023] For example:

[0024]

[0025] in, The frequency deviation is caused by errors during product implementation, and n takes different values. .

[0026] In one possible design, the frequency domain positions of N frequency-modulated continuous waves are evenly distributed in the frequency domain, and the interval between the frequency domain positions of two adjacent frequency-modulated continuous waves is a fixed value. In other words, the waveforms of N frequency-modulated continuous waves can be frequency-hopping at equal intervals in the frequency domain. Specifically, the equal-interval frequency hopping can be either increasing or decreasing at equal intervals, and this application does not impose any restrictions.

[0027] In one possible design, under the condition of equal-interval frequency hopping, , It can be configured as follows:

[0028]

[0029] ;

[0030] ;

[0031] in, Let N be the frequency-modulated continuous waves, and let the index of the frequency-modulated continuous wave be 0. Let N be the frequency domain position of the frequency-modulated continuous wave with index 0. The duration of each frequency-modulated continuous wave in a plurality of frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

[0032] Understandably, in practical applications, the above formula may have other variations.

[0033] In this way, it can be ensured that two adjacent frequency-modulated continuous waves (in the time domain) will not overlap in time, and the radar has a large speed measurement range.

[0034] In one possible design, the waveforms of the N frequency-modulated continuous waves can be randomly frequency-hopping in the frequency domain. For example, the first device can determine the frequency domain position of each frequency-modulated continuous wave in the N frequency-modulated continuous waves based on the frequency-hopping capability of the radar.

[0035] in this case, , It can be configured as follows:

[0036]

[0037] ;

[0038] in, , Let N be the frequency-modulated continuous waves, and let the index of the frequency-modulated continuous wave be 0. Let N be the frequency domain position of the frequency-modulated continuous wave with index 0. The duration of each of N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

[0039] Understandably, in practical applications, the above formula may have other variations.

[0040] It should be noted that this design is not limited to random frequency hopping; it is applicable to any situation where the frequency domain position of each of the N frequency-modulated continuous waves can be determined.

[0041] In this way, it can be ensured that two adjacent frequency-modulated continuous waves (in the time domain) will not overlap in time, and the radar has a large speed measurement range.

[0042] Secondly, a signal receiving method is provided. This method can be executed by a second device, such as a radar, or it can be a chip installed in a communication device, such as a radar, or other devices. This application does not impose any limitations. The first device and the second device can be integrated into one chip or integrated into different chips. This application does not impose any limitations. The method includes: receiving a second frequency-modulated continuous wave sequence, wherein the second frequency-modulated continuous wave sequence is a signal formed by a first frequency-modulated continuous wave sequence transmitted by the first device and then propagating through space and reflecting off a target; determining target information based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence, the information including speed and / or distance; wherein the first frequency-modulated continuous wave sequence includes N frequency-modulated continuous waves, where N is an integer greater than or equal to 1, and the product of the time-domain position and the corresponding frequency-domain position of the first frequency-modulated continuous wave in the N frequency-modulated continuous waves satisfies a first condition.

[0043] In this scheme, the second device determines the target's speed, distance, and other information based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence. Since the first frequency-modulated continuous wave sequence is a pre-designed waveform (i.e., the product of the time domain position and the corresponding frequency domain position in the first frequency-modulated continuous wave among N frequency-modulated continuous waves satisfies the first condition), the second device can use a simple digital signal processing method to estimate the target's parameters, ensuring the radar's speed measurement performance.

[0044] For an introduction to the first frequency modulated continuous wave sequence, please refer to the relevant content in the first aspect above, which will not be repeated here.

[0045] In one possible design, determining the target velocity based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence includes: determining the intermediate frequency signal sequence based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence; and processing the intermediate frequency signal sequence using FFT.

[0046] Of course, FFT is just an example and not a specific limitation.

[0047] In one possible design, before processing the intermediate frequency signal sequence using FFT, the method further includes: performing phase compensation on the second frequency-modulated continuous wave sequence or intermediate frequency signal sequence according to the interval of the frequency domain positions of the N frequency-modulated continuous waves.

[0048] This design compensates for the phase difference between two adjacent frequency-modulated continuous waves in the second frequency-modulated continuous wave sequence caused by distance, which can improve the accuracy of velocity detection.

[0049] Thirdly, a signal transmitting apparatus is provided, comprising a module / unit / means for performing the functions described in the first aspect or any possible design of the first aspect. This module / unit / means may be implemented in software, or in hardware, or the corresponding software may be implemented in hardware.

[0050] For example, the device may include: a processing unit for generating a first frequency-modulated continuous wave sequence; and a transmitting unit for transmitting the first frequency-modulated continuous wave sequence, the first frequency-modulated continuous wave sequence including N frequency-modulated continuous waves, where N is an integer greater than or equal to 1; wherein the product of the time-domain position and the corresponding frequency-domain position of the first frequency-modulated continuous wave in the N frequency-modulated continuous waves satisfies a first condition.

[0051] In one possible design, the first condition relates to the position of the first frequency-modulated continuous wave within N frequency-modulated continuous waves.

[0052] In one possible design, the frequency domain location includes the start frequency and / or center frequency, and the time domain location includes the start time and / or center time.

[0053] In one possible design, the first condition includes:

[0054] ;

[0055] Where n is the index of the frequency-modulated continuous wave in the N frequency-modulated continuous waves. ; Let n be the time-domain position of the frequency-modulated continuous wave with index n among N frequency-modulated continuous waves; Let n be the frequency domain position of the frequency-modulated continuous wave with index n among N frequency-modulated continuous waves; , These are the preset frequency hopping parameters.

[0056] In one possible design, the frequency domain positions of N frequency-modulated continuous waves are evenly distributed in the frequency domain, and the interval between the frequency domain positions of two adjacent frequency-modulated continuous waves is a fixed value. .

[0057] In one possible design, under the condition of equal-interval frequency hopping, , It can be configured as follows:

[0058]

[0059] ;

[0060] ;

[0061] in, Let N be the frequency-modulated continuous waves, and let the index of the frequency-modulated continuous wave be 0. Let N be the frequency domain position of the frequency-modulated continuous wave with index 0. The duration of each frequency-modulated continuous wave in a plurality of frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

[0062] In one possible design, under random frequency hopping, , It can be configured as follows:

[0063]

[0064] ;

[0065] in, , Let N be the frequency-modulated continuous waves, and let the index of the frequency-modulated continuous wave be 0. Let N be the frequency domain position of the frequency-modulated continuous wave with index 0. The duration of each of N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

[0066] Fourthly, a signal receiving apparatus is provided, comprising a module / unit / means for performing the functions described in the second aspect or any possible design of the second aspect. This module / unit / means may be implemented in software, or in hardware, or the corresponding software may be implemented in hardware.

[0067] For example, the device may include: a receiving unit for receiving a second frequency-modulated continuous wave sequence, wherein the second frequency-modulated continuous wave sequence is a signal formed by the first frequency-modulated continuous wave sequence after being transmitted by the first device and propagating through space and being reflected by a target; and a processing unit for determining target information based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence, wherein the information includes speed and / or distance; wherein the first frequency-modulated continuous wave sequence includes N frequency-modulated continuous waves, where N is an integer greater than or equal to 1, and the product of the time-domain position and the corresponding frequency-domain position of the first frequency-modulated continuous wave in the N frequency-modulated continuous waves satisfies a first condition.

[0068] Optionally, the processing unit is specifically used to: determine the intermediate frequency signal sequence based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence; and process the intermediate frequency signal sequence using FFT.

[0069] Optionally, the processing unit can also be used to: perform phase compensation on the second frequency-modulated continuous wave sequence or intermediate frequency signal sequence according to the interval of the frequency domain positions of the N frequency-modulated continuous waves before processing the intermediate frequency signal sequence with FFT.

[0070] Fifthly, a communication device is provided, comprising: at least one processor and an interface circuit; the interface circuit is configured to receive signals from other devices outside the device and transmit them to the processor or send signals from the processor to other devices outside the device, wherein the processor is configured to implement the method described in the first aspect or any possible design of the first aspect or the second aspect or any possible design of the second aspect through logic circuits or executing code instructions.

[0071] A sixth aspect provides a radar system comprising: a first means for performing the method as described in the first aspect or any possible design of the first aspect; and a second means for performing the method as described in the second aspect or any possible design of the second aspect.

[0072] A seventh aspect provides a terminal device comprising: a first means for performing the method as described in the first aspect or any possible design of the first aspect; and a second means for performing the method as described in the second aspect or any possible design of the second aspect.

[0073] Optionally, the terminal device can be a vehicle, drone, helicopter, airplane, ship, intelligent transportation equipment, or smart home device, etc. This application does not limit the specific form of the terminal device.

[0074] Eighthly, a computer-readable storage medium is provided, wherein a computer program or instructions are stored therein, which, when executed by a communication device, implement the method described in the first aspect or any possible design of the first aspect, or in the second aspect or any possible design of the second aspect.

[0075] Ninth aspect, a computer program product is provided, the computer program product storing instructions that, when run on a computer, cause the computer to perform the method as described in the first aspect or any possible design of the first aspect, or the second aspect or any possible design of the second aspect.

[0076] For the beneficial effects of aspects three through nine above, please refer to the technical effects that can be achieved by the corresponding designs in aspects one or two above, which will not be repeated here. Attached Figure Description

[0077] Figure 1 This is a schematic diagram illustrating the working principle of millimeter-wave radar.

[0078] Figure 2 This is a schematic diagram of a frequency-modulated continuous wave.

[0079] Figure 3 A schematic diagram of a frequency-modulated continuous wave with multiple cycles;

[0080] Figure 4 This is a schematic diagram of the transmitted signal, reflected signal, and intermediate frequency signal;

[0081] Figure 5 This is a schematic diagram illustrating mutual interference between vehicle-mounted radars.

[0082] Figure 6 , Figure 7 A schematic diagram of a possible spurious intermediate frequency signal;

[0083] Figure 8 , Figure 9 A schematic diagram illustrating a possible interference signal overwhelming the target signal;

[0084] Figure 10 This is a schematic diagram of radar random frequency hopping.

[0085] Figure 11 This is a schematic diagram illustrating a possible application scenario of an embodiment of this application;

[0086] Figure 12 A flowchart illustrating a signal transmission method provided in an embodiment of this application;

[0087] Figure 13 A schematic diagram showing the time domain and frequency domain range of a frequency-modulated continuous wave;

[0088] Figure 14 This is a schematic diagram showing the correspondence between the time-domain and frequency-domain positions of a possible frequency-modulated continuous wave.

[0089] Figure 15 A flowchart illustrating a signal receiving method provided in an embodiment of this application;

[0090] Figure 16 A flowchart illustrating a possible signal processing method provided in an embodiment of this application;

[0091] Figure 17 A flowchart illustrating another possible signal processing method provided in this application embodiment;

[0092] Figure 18 This is a schematic diagram of the structure of a signal transmitting device provided in an embodiment of this application;

[0093] Figure 19 This is a schematic diagram of the structure of a signal receiving device provided in an embodiment of this application;

[0094] Figure 20 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0095] Millimeter waves refer to electromagnetic waves with wavelengths between 1 and 10 mm, corresponding to a frequency range of 30 to 300 GHz. Within this frequency band, the characteristics of millimeter waves are highly suitable for automotive applications. For example, they offer a large bandwidth, abundant frequency domain resources, and low antenna sidelobes, which are beneficial for imaging or quasi-imaging; their short wavelength allows for smaller radar equipment size and antenna aperture, resulting in lighter weight; their narrow beamwidth is significantly narrower than microwave beamwidth for the same antenna size, leading to higher radar resolution; and they have strong penetration capabilities, allowing them to penetrate smoke, dust, and fog compared to lidar and optical systems, enabling all-weather operation.

[0096] Millimeter-wave radar operates in the millimeter-wave band and typically includes components such as an oscillator, transmitting antenna, receiving antenna, mixer, processor, and controller. For example... Figure 1The diagram illustrates the working principle of a millimeter-wave radar. An oscillator generates a radar signal whose frequency increases linearly with time; this signal is typically a frequency-modulated continuous wave (FMCW). A portion of this radar signal is output to a mixer via a directional coupler as the local oscillator signal, while another portion is transmitted through a transmitting antenna. A receiving antenna receives the radar signal reflected back from an object in front of the vehicle (also called the reflected signal or echo signal). The mixer mixes the received radar signal with the local oscillator signal to obtain an intermediate frequency (IF) signal (or IF echo signal). The IF signal contains information such as the relative distance, speed, and angle between the target and the radar system. After passing through a low-pass filter and amplification, the IF signal is sent to a processor. The processor processes the received signal, performing actions such as Fast Fourier Transform and spectral analysis to obtain information about the target's distance, speed, and angle relative to the radar system. Finally, the processor outputs this information to the controller to control the vehicle's behavior.

[0097] The frequency-modulated continuous wave waveform of millimeter-wave radar is generally a sawtooth wave or a triangular wave. The following will take the sawtooth wave as an example to introduce the ranging principle of millimeter-wave radar in detail. The ranging principle of the triangular wave is similar.

[0098] like Figure 2 As shown, a linear frequency modulated continuous wave is a signal whose frequency changes linearly with time.

[0099] like Figure 3 As shown, the oscillator of the millimeter-wave radar outputs multiple cycles of frequency-modulated continuous waves, where the period of the frequency-modulated continuous wave (the time from the start to the end of the frequency-modulated continuous wave) is... The slope is The bandwidth is B, and its starting frequency is . Figure 2 The frequency-modulated continuous wave signal shown is also called a linear frequency-modulated pulse (chirp) signal.

[0100] The equivalent baseband signal of a single-cycle frequency-modulated continuous wave output from the oscillator of a millimeter-wave radar can be expressed as:

[0101] (Formula 1.1)

[0102] Where A represents the amplitude of the equivalent baseband signal, The slope represents the equivalent baseband signal. Indicates the equivalent baseband signal at frequency The corresponding intercepts of the coordinate axes, Let represent the initial phase of the equivalent baseband signal, and exp represent the exponential function of e. Since frequency is defined as the rate of change of phase relative to time, the frequency of the above equivalent baseband signal is:

[0103] (Formula 1.2)

[0104] The image of Formula 1.2 is as follows Figure 3 As shown.

[0105] The equivalent baseband signal of the nth period frequency-modulated continuous wave emitted by the oscillator, after up-conversion, is radiated outward by the transmitting antenna of the millimeter-wave radar. The transmitted signal can be expressed as:

[0106] (Formula 1.3)

[0107] When the signal encounters an obstacle, it is reflected back and then received by the millimeter-wave radar. The waveforms of the transmitted and reflected signals are identical, except that the reflected signal waveform has a time delay relative to the transmitted signal waveform. For reference Figure 4 .exist Figure 4 In this context, the echo signal is the reflected signal. The reflected signal of the nth period frequency-modulated continuous wave can be expressed as:

[0108] (Formula 1.4)

[0109] in, It is the amplitude of the equivalent baseband signal emitted by the oscillator after passing through the transmitting antenna gain, target reflection, propagation loss, and receiving antenna gain. The time delay between the transmitter of the millimeter-wave radar sending the radar signal and the receiver receiving the echo signal (i.e., the reflected signal) is as follows: Figure 4 As shown, this time delay is twice the distance / speed of light. Additionally, in Figure 4 middle, This indicates the echo delay corresponding to the maximum detection range of the millimeter-wave radar, that is, This refers to the time delay of the reflected signal received by the millimeter-wave radar relative to the transmitted signal when the distance between the millimeter-wave radar and the target is the maximum distance that the millimeter-wave radar can detect. Distance from target d The relationship can be represented as:

[0110] (Formula 1.5)

[0111] The radar echo delay is caused by the reference distance. It is the radial relative velocity between the target and the radar. The speed is the speed of light. (Considering speed) Much less than the speed of light For baseband signals, the contribution of the second term in the above equation is very small in subsequent detection, so the second term in equation (1.5) is ignored in baseband signals; however, in carrier frequencies, the second term plays a crucial role in speed detection, so this term is retained, resulting in:

[0112] (Formula 1.6)

[0113] The mixer of this millimeter-wave radar mixes the received signal with the local oscillator signal, and after passing through a low-pass filter, outputs an intermediate frequency (IF) signal, which is represented as:

[0114] (Formula 1.7)

[0115] in , , It is the Doppler frequency formed by the radial relative velocity between the target and the detection radar. The intermediate frequency (IF) signal of the nth period is sampled by the ADC to obtain the IF sampled signal, which is then fed into the processor for Fourier transform to obtain the IF frequency. :

[0116] (Formula 1.8)

[0117] Due to general ,but Then we have:

[0118] (Formula 1.9)

[0119] Therefore, the distance between the millimeter-wave radar and the target d for:

[0120] (Formula 1.10)

[0121] The above derivation is for a single target. It is equally applicable to the case of multiple targets. That is, after receiving and mixing, multiple intermediate frequency signals will be obtained. After being sent to the processor for Fourier transform, the intermediate frequency corresponding to each target can be obtained.

[0122] The above derivation shows that the frequency difference between the transmitted and received signals (i.e., the frequency of the intermediate frequency signal) and the time delay are linearly related: the farther the target, the later the received reflected signal, and therefore the greater the frequency difference between the reflected and transmitted signals. Thus, the distance between the radar and the target can be determined by judging the frequency of the intermediate frequency signal. Furthermore, the above radar signal processing procedure is merely an example and does not limit the specific radar processing procedures.

[0123] For speed detection, as can be seen from Equation 1.7, the phase difference between the intermediate frequency signals of two adjacent cycles at the same sampling point is a constant, that is:

[0124] (Formula 1.11)

[0125] The Doppler frequency can be obtained by performing a Fourier transform on the phase sequence of an intermediate frequency signal with multiple consecutive cycles at the same time sampling point. The relationship between it and the radial relative velocity v of the target can be expressed as:

[0126] (Formula 1.12)

[0127] in, The wavelength is the radar signal wavelength.

[0128] Therefore, the radial relative velocity between the radar and the target for:

[0129] (Formula 1.13)

[0130] As the penetration rate of vehicle-mounted radar increases, the mutual interference between vehicle-mounted radars becomes more and more serious, which will greatly reduce the radar detection probability or increase the false alarm probability of radar detection, causing a significant impact on driving safety and comfort.

[0131] For reference Figure 5 This diagram illustrates the mutual interference between vehicle-mounted radars. Radar 1 transmits a signal and receives the reflected signal from the target. Simultaneously, radar 1's receiving antenna also receives either the transmitted or reflected signal from radar 2. Therefore, the transmitted or reflected signal from radar 2 received by radar 1 constitutes interference for radar 1.

[0132] For example, let radar 1 be an observation radar, and the slope of its frequency-modulated continuous wave is... The intercept is The cycle is Radar 2 is a jamming radar; the slope of its frequency-modulated continuous wave is... The intercept is At this point, let's assume = The echo delay corresponding to the maximum ranging range of Radar 1 is (That is, the time delay calculated by substituting the radar's maximum detection range into Formula 1.6. For example, if the radar's maximum detection range is 250m, the time delay calculated by substituting into Formula 1.6 is 1.67.) The time delay of the interference signal from radar 2 reaching the receiver of radar 1 is (s). Considering the timing error at the radar transmission time... (For example, the error in transmission time due to timing errors in the Global Positioning System (GPS), such as 60 ns). The time interval for radar to detect the received signal is... ~ .

[0133] If the slope of the radar signal transmitted by radar 1 is the same as the slope of the radar signal transmitted by radar 2, that is... = If the operating frequency bands of the two overlap, a false alarm will occur. The intermediate frequency signal generated at the radar receiver in this case is:

[0134] (Formula 1.14)

[0135] in, ; It is the signal amplitude of the jamming radar signal after passing through the transmitting antenna gain, target reflection, propagation loss, and receiving antenna gain. It is the initial phase of the interfering radar signal. It is the Doppler frequency generated by the radial relative velocity between the target and the detection radar that interferes with the radar signal. It is the time delay between the transmission of the jamming radar signal by the transmitter and the reception of the signal by the jammed radar receiver.

[0136] Figure 6 , Figure 7 This is a schematic diagram of a possible spurious intermediate frequency signal. (Example:) Figure 6 As shown, radar 1 transmits a signal to the target and receives a reflected signal from the target. However, within the time range between radar 1 transmitting the signal and receiving the reflected signal, radar 1's receiving antenna receives either the transmitted or reflected signal from radar 2 (dashed line). The signal waveforms of radar 1 and radar 2 are identical, and their frequency sweep bandwidths are the same. Within radar 1's target echo observation range, radar 1 receives the signal shown by the dashed line at the corresponding frequency; therefore, radar 1 considers "target 1" to exist. During the signal processing time interval (…), radar 1… If radar 1 detects both the signal shown by the dashed line and the reflected signal shown by the solid line, it will mistakenly interpret the signal shown by the dashed line as a reflected signal from an object in front of it, thus generating a false intermediate frequency (IF) signal. Radar 1 can then perform a spectral analysis after performing a Fast Fourier Transform (FFT) to identify two peaks, such as... Figure 7 As shown, each peak corresponds to a target. Radar 1 believes that both "Target 1" and "Target 2" exist simultaneously. Radar 1 mistakenly believes that "Target 1" exists ahead, when in fact "Target 1" does not exist. This is called a "ghost" or "false alarm." A false alarm will cause the autonomous vehicle to slow down or brake suddenly when there is no object in front, reducing driving comfort.

[0137] If there is a difference between the slope of the radar signal transmitted by radar 1 and the radar signal transmitted by radar 2, that is... If this happens, there will be cases of missed detection.

[0138] Figure 8 , Figure 9 This is a schematic diagram illustrating a possible scenario where interference signals overwhelm the target signal. (Example) Figure 8 As shown, radar 1 transmits a signal to the target and receives the reflected signal from the target. However, within the target echo observation range of radar 1, the receiving antenna of radar 1 receives either the transmitted or reflected signal from radar 2 (dashed line). The signal waveforms of radar 1 and radar 2 differ in slope, especially during the signal detection time interval of radar 1 (…). Within the system, the reflected signal from radar 1 and the correlated signal from radar 2 will be detected simultaneously. After mixing the detected correlated signal from radar 2 with the reflected signal from radar 1, an intermediate frequency signal containing various frequency components will be generated.

[0139] (1.15)

[0140] in, ;

[0141] After Fast Fourier Transform, as follows Figure 9 As shown, an interference platform appears, making the actual target less "protruding," which makes detection difficult and increases the possibility of missed detections. Missed detections can cause autonomous vehicles to mistakenly believe there is no object in front of them, failing to slow down or brake, leading to traffic accidents and reducing vehicle safety.

[0142] Therefore, reducing interference between vehicle radars is a problem that must be solved in order to improve vehicle comfort and safety.

[0143] One possible solution is to use radar frequency agility technology, which involves rapidly changing the frequency of the radar waveform to prevent interference between multiple radars. For example... Figure 10 As shown, radar reduces the probability of mutual interference by using frequency agility (random frequency hopping). While this method does reduce the probability of mutual interference to a certain extent, it prevents the radar from using simple digital signal processing methods (such as Fast Fourier Transform (FFT)) to measure speed, thus limiting the radar's functionality.

[0144] Therefore, the technical solution of the embodiments of this application is provided. In the embodiments of this application, a radar time-frequency jumping waveform is designed: the time-domain position and the corresponding frequency-domain position of each frequency-modulated continuous wave transmitted by the radar are correlated, for example, the product of the time-domain position and the corresponding frequency-domain position satisfies a preset condition. In this way, the radar can use the designed waveform to determine the time-domain position and frequency-domain position of each frequency-modulated continuous wave transmitted by the radar, thereby reducing the probability of radar mutual interference and allowing velocity measurement using simple digital signal processing methods (such as FFT).

[0145] It is understood that the technical solutions of the embodiments of this application can be applied to vehicle-mounted radar systems or other radar systems, as long as there is interaction between radars in the system, this application is applicable. The radar can be millimeter-wave radar or other types of radar; this application does not impose any limitations.

[0146] like Figure 11 The diagram illustrates a possible application scenario of this application. This application scenario can include autonomous driving, autonomous driving, intelligent driving, and connected driving. Radar can be installed on motor vehicles (e.g., driverless cars, intelligent cars, electric cars, digital cars, etc.), drones, railcars, bicycles, traffic lights, speed measuring devices, or network equipment (e.g., base stations, terminal equipment in various systems), etc. In addition to radar, these devices can also be equipped with processing and communication devices. This application is applicable to radar between vehicles, radar between vehicles and drones or other devices, or radar between other devices. Furthermore, radar, processing, and communication devices can be installed on mobile devices, such as a vehicle-mounted radar, or they can be installed on fixed equipment, such as roadside units (RSUs). This application does not limit the location or function of the radar, processing, and communication devices.

[0147] This application provides a signal transmission method. Please refer to [link to relevant documentation]. Figure 12 Here is a flowchart of the method. Figure 12The method provided in the illustrated embodiment can be executed by a first device. The first device is, for example, a radar (or, referred to as a radar device), or it can be a chip installed in a communication device, such as a radar (or, a radar device), or other devices, which are not limited in this application.

[0148] S11. The first device generates a first frequency-modulated continuous wave sequence; wherein, the first frequency-modulated continuous wave sequence includes N frequency-modulated continuous waves, where N is an integer greater than or equal to 1; the product of the time domain position and the corresponding frequency domain position of the first frequency-modulated continuous wave in the N frequency-modulated continuous waves satisfies the first condition.

[0149] The first frequency-modulated continuous wave can be any one of the N frequency-modulated continuous waves, and this application does not impose any restrictions.

[0150] As described above, a frequency-modulated continuous wave (FM continuous wave) is a signal whose frequency varies linearly with time. In the following text, for ease of description, the duration of the FM continuous wave (i.e., the time from start to end) will be referred to as its time domain range, and the frequency variation range (i.e., bandwidth) will be referred to as its frequency domain range. For example... Figure 13 The diagram illustrates the time domain range [t1, t2] and frequency domain range [f1, f2] of a frequency-modulated continuous wave. This is understandable. Figure 13 The time domain range, frequency domain range, and linear relationship between frequency and time shown for the frequency-modulated continuous wave are merely examples and not specific limitations.

[0151] The time-domain position within the first frequency-modulated continuous wave can be any time-domain position within the time-domain range of the first frequency-modulated continuous wave, such as the starting time-domain position (i.e., the start time of the first frequency-modulated continuous wave), the ending time-domain position (i.e., the end time of the first frequency-modulated continuous wave), the center time-domain position (i.e., the midpoint between the start and end times of the first frequency-modulated continuous wave), or other time-domain positions, etc., and this application does not impose any restrictions on this. For example, taking the first frequency-modulated continuous wave as... Figure 13 Taking the frequency-modulated continuous wave as an example, the time domain range of the first frequency-modulated continuous wave is [t0, t2]. Therefore, the starting time domain position of the first frequency-modulated continuous wave is t0, and the center time domain position is... The endpoint time domain position is t2.

[0152] Since a frequency-modulated continuous wave (FM continuous wave) is a signal whose frequency changes linearly with time, there is a one-to-one correspondence between the time-domain position within the time domain of the first FM continuous wave and the frequency-domain position within its frequency domain. In other words, every time-domain position within the time domain of the first FM continuous wave can be matched with a corresponding frequency-domain position within its frequency domain, or vice versa. For example, considering the first FM continuous wave as... Figure 13 Taking the frequency-modulated continuous wave as an example, the frequency domain position corresponding to the starting time domain position t0 in the first frequency-modulated continuous wave is f0, the frequency domain position corresponding to the ending time domain position t2 is f2, and the frequency domain position corresponding to the time domain position t1 (t1 is a time domain position between the starting time domain position t0 and the ending time domain position t2) is f1.

[0153] It should be noted that in actual product implementation, the correspondence between time-domain and frequency-domain locations can have a certain range of error. For example, Figure 14 As shown, according to the linear relationship between frequency and time in frequency-modulated continuous wave, the time domain position corresponding to frequency domain position f1 should be t1. However, since the value of t1 has a decimal part and this decimal part is an infinite non-repeating decimal, it is difficult to accurately implement in the product. Therefore, the time domain position corresponding to frequency domain position f1 can be shifted to t1' near t1, where t1 and... The deviation is Δt, which makes the time domain position corresponding to the frequency domain position f1 t1'. The value of t1' is an integer, or the value of t1' has a decimal part and that decimal part is a finite decimal. It should be understood that the above is only an example and not a specific limitation. In actual applications, there may be other reasons that cause errors, and this application does not impose any restrictions.

[0154] In one possible implementation, the first condition relates to the position of the first frequency-modulated continuous wave within the N frequency-modulated continuous waves. Furthermore, for each of the N frequency-modulated continuous waves, the product of its time-domain position and its corresponding frequency-domain position can satisfy certain conditions. These conditions can differ for different frequency-modulated continuous waves, and the conditions satisfied by the product of the time-domain position and its corresponding frequency-domain position for each frequency-modulated continuous wave are all related to the position of that frequency-modulated continuous wave within the N frequency-modulated continuous waves.

[0155] In one possible implementation, the first condition can be a preset value, namely, the product of the time-domain position and the corresponding frequency-domain position within the first frequency-modulated continuous wave. This preset value can be calculated based on the position of the first frequency-modulated continuous wave within N frequency-modulated continuous waves. The product of the time-domain position and the corresponding frequency-domain position of different frequency-modulated continuous waves among the N frequency-modulated continuous waves can be different preset values.

[0156] For example, the first condition may include:

[0157] (1.16)

[0158] Where n is the index of the frequency-modulated continuous wave in the N frequency-modulated continuous waves. ; Let n be the time-domain position of the frequency-modulated continuous wave with index n among N frequency-modulated continuous waves; Let n be the frequency domain position of the frequency-modulated continuous wave with index n among N frequency-modulated continuous waves; , These are the preset frequency hopping parameters.

[0159] for , The value of can be configured based on the radar's hardware capabilities and target detection performance indicators. Optionally, within a frame, , Using fixed parameter values, different parameter values ​​can be used for different frames. Accordingly, the value of N mentioned above can be the number of frequency-modulated continuous waves transmitted by the first device within a frame.

[0160] Understandably, in practical applications, the first condition can also be a variation of formula 1.16 above. For example, considering that the correspondence between time-domain and frequency-domain positions can have a certain range of error, formula 1.16 above can also be transformed into:

[0161] (1.17)

[0162] in, The time deviation is caused by errors during product realization; when n takes different values... ;

[0163] or,

[0164] (1.18)

[0165] in, The frequency deviation is caused by errors during product implementation, and n takes different values. .

[0166] Of course, Formula 1.17 is just one example. In practical applications, Formula 1.16 can have other variations. However, no matter how the form is changed, as long as it can be transformed into a function format that is the same as or similar to Formula 1.16, it can be used.

[0167] In one possible design, the waveforms of the N frequency-modulated continuous waves can be frequency-hopping at equal intervals in the frequency domain, meaning the frequency domain positions of the N frequency-modulated continuous waves are distributed at equal intervals in the frequency domain, where the interval between the frequency domain positions of two adjacent frequency-modulated continuous waves is a fixed value. .

[0168] Specifically, equal-interval frequency hopping can be achieved by increasing at equal intervals (e.g.: ,in (Take a positive value), or it can be a decreasing value at equal intervals (e.g.: ,in (The value can be positive), this application does not impose any restrictions.

[0169] in this case, , It can be configured as follows:

[0170] (1.19)

[0171] (1.20)

[0172] in, ; Let N be the frequency-modulated continuous waves, and let the index of the frequency-modulated continuous wave be 0. Let N be the frequency domain position of the frequency-modulated continuous wave with index 0. The duration of each frequency-modulated continuous wave in multiple frequency-modulated continuous waves (it should be noted that for time-division multiplexing (TDM) multi-input multi-output (MIMO) radars), The duration of each of the multiple frequency-modulated continuous waves transmitted by the same transmitting antenna, where the durations of the N frequency-modulated continuous waves are the same (i.e., the duration from start time to end time is the same).

[0173] Similarly, in practical applications, formulas 1.19 and 1.20 can have other variations. However, no matter how the form is changed, as long as it can be transformed into a function format that is the same as or similar to formulas 1.19 and 1.20, it can be used.

[0174] Through the above , The parameter design ensures that two adjacent frequency-modulated continuous waves (FM waves) will not overlap in time (in the time domain), and that the radar has a large speed measurement range.

[0175] In another possible design, the waveforms of the N frequency-modulated continuous waves can be randomly frequency-hopping in the frequency domain. For example, the first device can determine the frequency domain position of each of the N frequency-modulated continuous waves based on the radar's frequency-hopping capability. The first device needs to select the frequency-hopping range based on the radar's capabilities (for example, if the radar can only operate in the 77-78 GHz band, then the frequency of the frequency-modulated continuous waves can only be within this 1 GHz range and cannot exceed it).

[0176] In this case, assuming This assumption generally holds true for vehicle-mounted radar. , It can be configured as follows:

[0177] (1.21)

[0178] (1.22)

[0179] in, Let N be the frequency-modulated continuous waves, and let the index of the frequency-modulated continuous wave be 0. Let N be the frequency domain position of the frequency-modulated continuous wave with index 0. The duration of each of N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

[0180] Similarly, in practical applications, formulas 1.21 and 1.22 can have other variations. However, no matter how the form is changed, as long as it can be transformed into a function format that is the same as or similar to formulas 1.21 and 1.22, it can be used.

[0181] It should be noted that this design is not limited to random frequency hopping; it is applicable to any situation where the frequency domain position of each of the N frequency-modulated continuous waves can be determined.

[0182] Through the above , The parameter design ensures that two adjacent frequency-modulated continuous waves (FM waves) will not overlap in time (in the time domain), and that the radar has a large speed measurement range.

[0183] In addition, the embodiments of this application can also describe "N frequency-modulated continuous waves" as "N cycles of frequency-modulated continuous waves", wherein the N frequency-modulated continuous waves correspond one-to-one with the N cycles, and the duration of each cycle is the duration of the frequency-modulated continuous wave corresponding to that cycle.

[0184] In the embodiments of this application, the first device can determine the time domain position based on the frequency domain position (for example, first determine the frequency domain position of the first frequency-modulated continuous wave, and then determine the time domain position of the first frequency-modulated continuous wave based on the frequency domain position of the first frequency-modulated continuous wave and the first condition), or it can determine the frequency domain position based on the time domain position (for example, first determine the time domain position of the first frequency-modulated continuous wave, and then determine the time domain position of the first frequency-modulated continuous wave based on the time domain position of the first frequency-modulated continuous wave and the first condition). This application does not impose any restrictions. Similarly, for other frequency-modulated continuous waves in the first frequency-modulated continuous wave sequence besides the first frequency-modulated continuous wave, the frequency domain position can be determined based on the time domain position, or the time domain position can be determined based on the frequency domain position. This application also does not impose any restrictions.

[0185] S12, The first device transmits the first frequency-modulated continuous wave sequence.

[0186] The above describes the signal transmission process of a single radar. When multiple radars exist simultaneously, each of the multiple radars can use the above method to transmit signals.

[0187] In practical implementation, it is only necessary to ensure that the signal waveforms corresponding to different radars have different frequency domain positions at the same time domain position (i.e., to avoid frequency domain resource conflicts between different radars at the same time). This can reduce or even eliminate mutual interference between radars. Furthermore, since each radar uses a pre-designed waveform to transmit signals, the receiving device corresponding to each radar can use simple digital signal processing methods (such as FFT) to measure speed. Therefore, it is possible to reduce the probability of radar mutual interference while ensuring the speed measurement performance of the radar.

[0188] The following describes the signal receiving process corresponding to the above signal transmission process (i.e., steps S11~S12):

[0189] This application provides a signal receiving method. Please refer to [link to relevant documentation]. Figure 15 Here is a flowchart of the method. In the following description, this method will be applied to... Figure 15 The network architecture shown is an example. Figure 15 The method provided in the illustrated embodiment can be executed by a second device. The second device may be, for example, a radar (or, referred to as a radar device), or it may be a chip installed in a communication device, such as a radar (or, a radar device), or other devices; this application does not impose any limitations. The first and second devices may be integrated into a single chip or integrated into different chips; this application does not impose any limitations.

[0190] S21. The second device receives the second frequency-modulated continuous wave sequence, wherein the second frequency-modulated continuous wave sequence is a signal formed by the first frequency-modulated continuous wave sequence after being transmitted by the first device and propagating through space and being reflected by the target.

[0191] Regarding the first frequency modulated continuous wave sequence, please refer to the above description, which will not be repeated here.

[0192] Understandably, after the first frequency-modulated continuous wave sequence is emitted from the first device, it propagates through space, encounters an obstacle (such as a target), is reflected by the obstacle, and then propagates through space again to be received by the receiving antenna of the second device. Due to target reflection and propagation loss, the waveform of the signal will change to some extent. Therefore, the signal emitted by the first device (i.e., the first frequency-modulated continuous wave sequence) and the signal received by the second device (i.e., the second frequency-modulated continuous wave sequence) may differ to some extent. For example, the waveform of the second frequency-modulated continuous wave sequence will have a time delay relative to the waveform of the first frequency-modulated continuous wave sequence. The specific expression can be found in Equations 1.3 and 1.4 above, and will not be repeated here.

[0193] S22. The second device determines the target information based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence.

[0194] For example, the second device mixes the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence to obtain an intermediate frequency (IF) signal sequence; then, it processes the IF signal sequence using a simple digital signal processing method to estimate the target's parameters, thereby obtaining relevant information such as the target's velocity, distance, or angle. Optionally, this simple digital signal processing method includes FFT.

[0195] Understandably, when the second device performs signal processing, it needs to compensate for the phase difference between two adjacent frequency-modulated continuous waves (or frequency-modulated continuous waves of two adjacent periods) in the second frequency-modulated continuous wave sequence caused by distance, so as to obtain a more accurate target velocity.

[0196] Taking the design of N frequency-modulated continuous waves with equally spaced frequency domain positions as an example, the frequency domain interval between two adjacent frequency-modulated continuous waves is... In this case, the phase difference between two adjacent intermediate frequency signals is The parameter that needs to be estimated is... In this case, according to the relevant derivations introduced in Formulas 1.11 and 1.12 above, it can be seen that FFT can only be used to process the intermediate frequency signal to obtain the signal when the phase difference between the intermediate frequency signals of two adjacent periods at the same sampling point is a constant value. Therefore, the embodiments of this application need to include phase To eliminate the influence of phase compensation, phase compensation is required; otherwise, FFT estimation cannot be used to obtain accurate results. .

[0197] In practical implementation, the second device can perform phase compensation after obtaining the intermediate frequency sampling signal and distance information through mixing and low-pass filtering. More specifically, the first device can perform phase compensation on the intermediate frequency signal sequence before speed detection, or directly compensate for the speed detection deviation caused by distance after speed detection; this application does not impose any limitations on this.

[0198] The interval between the frequency domain positions of two adjacent frequency-modulated continuous waves in N frequency-modulated continuous waves is a fixed value. For example:

[0199] In one possible example, such as Figure 16 As shown, the processing of the intermediate frequency signal by the second device may include:

[0200] S30. Sample the intermediate frequency signal sequence to obtain the intermediate frequency sampled signal sequence;

[0201] Understandably, the intermediate frequency signal sequence here refers to an analog intermediate frequency signal with multiple cycles, while the intermediate frequency sampling signal sequence refers to a digital intermediate frequency sampling signal with multiple cycles.

[0202] S31. Perform two-dimensional (2D) FFT processing on the intermediate frequency sampled signal sequence to obtain the FFT results in the slow time dimension and the FFT results in the fast time dimension;

[0203] The 2D FFT processing includes distance-dimensional FFT processing and velocity-dimensional FFT processing. The distance dimension is also known as the fast time dimension, and the velocity dimension is also known as the slow time dimension.

[0204] Fast time-dimensional FFT processing includes performing an FFT on the intermediate frequency sampled signal for each cycle.

[0205] Slow-time FFT processing includes performing FFT on the intermediate frequency sampled signal for all periods at the same fast-time sampling point location.

[0206] Understandably, the two processes are generally performed sequentially. For example, the fast-time dimension FFT is performed first, followed by the slow-time dimension FFT. Since the fast-time dimension FFT can obtain the target distance, the slow-time dimension FFT is equivalent to performing an FFT on the intermediate frequency sampled signal of all periods at the same distance position after the fast-time dimension FFT. Of course, in actual operation, the slow-time dimension FFT can also be performed first, followed by the fast-time dimension FFT. This application does not restrict the order.

[0207] S32. Perform incoherent superposition on the FFT results in the slow time dimension, and then use Constant False Alarm Rate (CFAR) to detect the signal transmission delay caused by the target distance, i.e., the target delay. (That is, the time delay experienced during the process of the signal being transmitted from the first device, reflected by the target, and finally received by the second device).

[0208] S33. Extracting from the fast time dimension FFT result The corresponding sequences (complex numbers) form the target's slow time series (complex number array).

[0209] S34. Compensate for the phase difference between two adjacent frequency-modulated continuous wave sequences caused by distance in the slow time series (i.e., In After that, it made Thus, the phase-compensated slow time series is obtained;

[0210] S35. Perform FFT on the phase-compensated slow time series, and then perform CFAR (constant false alarm rate) detection to obtain the target velocity.

[0211] Understandably, CFAR is only one example, and other methods can be used to determine the velocity of a target in practical applications. This application does not impose any restrictions on this method.

[0212] This example demonstrates how phase compensation of the intermediate frequency signal sequence, performed after mixing and before velocity detection, can improve the accuracy of velocity detection.

[0213] In another possible example, the interval between the frequency domain positions of two adjacent frequency-modulated continuous waves in N frequency-modulated continuous waves is a fixed value. For example, Figure 17 As shown, the second device's processing of the intermediate frequency signal includes:

[0214] S40. Sample the intermediate frequency signal sequence to obtain the intermediate frequency sampled signal sequence;

[0215] S41. Perform two-dimensional (2D) FFT processing on the intermediate frequency sampled signal sequence to obtain the FFT results in the slow time dimension and the FFT results in the fast time dimension;

[0216] The specific implementation process of S41 can be found in S31, and will not be repeated here.

[0217] S42. Perform two-dimensional (2D) CFAR detection on the FFT results and the fast time dimension FFT results to obtain the target distance and target velocity;

[0218] The 2D CFAR example is just one example. In practical applications, other methods can be used to determine the target velocity and target distance. This application does not impose any restrictions.

[0219] Understandably, the target distance can be calculated using a velocity conversion factor. (Originated from slow-time FFT processing) get.

[0220] The target velocity includes the time delay due to the target distance. and frequency hopping interval The resulting error. For ease of description, let the target velocity be denoted as... .

[0221] S43. Compensate for the speed detection deviation caused by distance and output the compensated target speed.

[0222] Among them, the speed detection deviation can be specifically determined according to... Obtained through calculation.

[0223] For example, the target velocity obtained in S42 minus The compensated target speed can then be obtained. .

[0224] This example demonstrates how compensating for speed detection bias caused by distance before speed detection can improve the accuracy of speed detection.

[0225] As can be seen from the above signal transmission and reception processes, since the radar uses a pre-designed waveform to transmit signals, it can determine the time and frequency domain positions of each frequency modulated continuous wave. Therefore, in the signal reception stage, simple digital signal processing methods (such as FFT) can be used for speed measurement, which can reduce the probability of radar mutual interference while ensuring the radar's speed measurement performance.

[0226] The methods provided by the embodiments of this application have been described above with reference to the accompanying drawings. The apparatus provided by the embodiments of this application will be described below with reference to the accompanying drawings.

[0227] Based on the same technical concept, embodiments of this application provide a signal transmitting device, which includes a module / unit / means for performing the method executed by the first device in the above-described method embodiments. This module / unit / means can be implemented in software, or in hardware, or implemented in hardware executing corresponding software.

[0228] For example, see Figure 18 The device may include:

[0229] Processing unit 1801 is used to generate a first frequency-modulated continuous wave sequence;

[0230] The transmitting unit 1802 is used to transmit a first frequency-modulated continuous wave sequence, which includes N frequency-modulated continuous waves, where N is an integer greater than or equal to 1.

[0231] Among them, the product of the time domain position and the corresponding frequency domain position in the first frequency-modulated continuous wave of N frequency-modulated continuous waves satisfies the first condition.

[0232] The transmitting unit 1802 can be a transmitter (or transceiver) or a transmitting antenna, etc. The processing unit 1801 can be a processor.

[0233] Optionally, the first condition relates to the position of the first frequency-modulated continuous wave within the N frequency-modulated continuous waves.

[0234] Optionally, the frequency domain location includes the start frequency and / or the center frequency, and the time domain location includes the start time and / or the center time.

[0235] Optional, the first condition includes:

[0236] ;

[0237] Where n is the index of the frequency-modulated continuous wave in the N frequency-modulated continuous waves. ; Let n be the time-domain position of the frequency-modulated continuous wave with index n among N frequency-modulated continuous waves; Let n be the frequency domain position of the frequency-modulated continuous wave with index n among N frequency-modulated continuous waves; , These are the preset frequency hopping parameters.

[0238] Optionally, the frequency domain positions of the N frequency-modulated continuous waves are evenly distributed in the frequency domain, and the interval between the frequency domain positions of two adjacent frequency-modulated continuous waves is a fixed value. .

[0239] Optionally, in the case of equal-interval frequency hopping, , It can be configured as follows:

[0240]

[0241] ;

[0242] ;

[0243] in, Let N be the frequency-modulated continuous waves, and let the index of the frequency-modulated continuous wave be 0. Let N be the frequency domain position of the frequency-modulated continuous wave with index 0. The duration of each frequency-modulated continuous wave in a plurality of frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

[0244] Optionally, in the case of random frequency hopping, , It can be configured as follows:

[0245]

[0246] ;

[0247] in, , Let N be the frequency-modulated continuous waves, and let the index of the frequency-modulated continuous wave be 0. Let N be the frequency domain position of the frequency-modulated continuous wave with index 0. The duration of each of N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

[0248] It should be understood that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0249] Based on the same technical concept, embodiments of this application provide a signal receiving device, which includes a module / unit / means for performing the method executed by the second device in the above-described method embodiments. This module / unit / means can be implemented in software, or in hardware, or implemented by hardware executing corresponding software.

[0250] For example, see Figure 19 The device may include:

[0251] The receiving unit 1901 is used to receive a second frequency-modulated continuous wave sequence, wherein the second frequency-modulated continuous wave sequence is a signal formed by the first frequency-modulated continuous wave sequence after being transmitted by the first device and then propagated through space and reflected by the target.

[0252] Processing unit 1902 is configured to determine target information based on a second frequency-modulated continuous wave sequence and a first frequency-modulated continuous wave sequence, the information including velocity and / or distance;

[0253] The first frequency-modulated continuous wave sequence includes N frequency-modulated continuous waves, where N is an integer greater than or equal to 1. The product of the time-domain position and the corresponding frequency-domain position of the first frequency-modulated continuous wave in the N frequency-modulated continuous waves satisfies the first condition.

[0254] The receiving unit 1901 can be a receiver (or transceiver) or a receiving antenna, etc. The processing unit 1902 can be a processor.

[0255] Optionally, the first condition relates to the position of the first frequency-modulated continuous wave within the N frequency-modulated continuous waves.

[0256] Optionally, the frequency domain location includes the start frequency and / or the center frequency, and the time domain location includes the start time and / or the center time.

[0257] Optional, the first condition includes:

[0258] ;

[0259] Where n is the index of the frequency-modulated continuous wave in the N frequency-modulated continuous waves. ; Let n be the time-domain position of the frequency-modulated continuous wave with index n among N frequency-modulated continuous waves; Let n be the frequency domain position of the frequency-modulated continuous wave with index n among N frequency-modulated continuous waves; , These are the preset frequency hopping parameters.

[0260] Optionally, the frequency domain positions of the N frequency-modulated continuous waves are evenly distributed in the frequency domain, and the interval between the frequency domain positions of two adjacent frequency-modulated continuous waves is a fixed value. .

[0261] Optionally, in the case of equal-interval frequency hopping, , It can be configured as follows:

[0262]

[0263] ;

[0264] ;

[0265] in, Let N be the frequency-modulated continuous waves, and let the index of the frequency-modulated continuous wave be 0. Let N be the frequency domain position of the frequency-modulated continuous wave with index 0. The duration of each frequency-modulated continuous wave in a plurality of frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

[0266] Optionally, in the case of random frequency hopping, , It can be configured as follows:

[0267]

[0268] ;

[0269] in, , Let N be the frequency-modulated continuous waves, and let the index of the frequency-modulated continuous wave be 0. Let N be the frequency domain position of the frequency-modulated continuous wave with index 0. The duration of each of N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

[0270] Optionally, the processing unit 1902 is specifically used to: determine the intermediate frequency signal sequence based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence; and process the intermediate frequency signal sequence using a Fast Fourier Transform (FFT).

[0271] Optionally, the processing unit 1902 can also be used for:

[0272] Before using FFT to process the intermediate frequency signal sequence, the process also includes: performing phase compensation on the second frequency modulated continuous wave sequence or intermediate frequency signal sequence according to the interval of the frequency domain positions of the N frequency modulated continuous waves.

[0273] It should be understood that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0274] In specific implementation, the device provided in the embodiments of this application can have various product forms. Several possible product forms are introduced below.

[0275] See Figure 20 This application embodiment also provides a communication device, which includes at least one processor 2001 and an interface circuit 2002; the interface circuit 2002 is used to receive signals from other devices outside the device and transmit them to the processor 2001 or send signals from the processor 2001 to other communication devices outside the device, and the processor 2001 is used to implement the method executed by the first device or the second device through logic circuits or execution code instructions.

[0276] It should be understood that the processor mentioned in the embodiments of this application can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor, implemented by reading software code stored in memory.

[0277] For example, the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0278] It should be understood that the memory mentioned in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate Synchronous DRAM (DDR SDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct RAM (DR RAM).

[0279] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) can be integrated into the processor.

[0280] It should be noted that the memories described herein are intended to include, but are not limited to, these and any other suitable types of memories.

[0281] Based on the same technical concept, embodiments of this application also provide a computer-readable storage medium, including a program or instructions that, when run on a computer, cause the method performed by the first or second device described above to be executed.

[0282] Based on the same technical concept, embodiments of this application also provide a computer program product containing instructions, which stores instructions that, when run on a computer, cause the method executed by the first or second device to be performed.

[0283] Based on the same technical concept, embodiments of this application also provide a radar system, including the above-described signal transmitting device and / or signal receiving device.

[0284] Based on the same technical concept, embodiments of this application also provide a terminal device, including the transmitting device and / or signal receiving device described above. The terminal device may be a vehicle, drone, helicopter, airplane, ship, intelligent transportation equipment, or smart home device, etc. Embodiments of this application do not limit the specific form of the terminal device.

Claims

1. A signal transmission method, characterized in that, include: Generate the first frequency-modulated continuous wave sequence; Transmit the first frequency-modulated continuous wave sequence, which includes N frequency-modulated continuous waves, where N is an integer greater than or equal to 1; Among them, the product of the time domain position and the corresponding frequency domain position in the first frequency-modulated continuous wave of the N frequency-modulated continuous waves satisfies the first condition; The first condition includes: ； Where n is the index of the frequency-modulated continuous wave among the N frequency-modulated continuous waves. ; The time-domain position of the frequency-modulated continuous wave with index n among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index n among the N frequency-modulated continuous waves; , These are the preset frequency hopping parameters; The frequency domain positions of the N frequency-modulated continuous waves are evenly distributed in the frequency domain, and the interval between the frequency domain positions of two adjacent frequency-modulated continuous waves is a fixed value. ; ； ； in, The time-domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The duration of each of the N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

2. The method as described in claim 1, characterized in that, The first condition is related to the position of the first frequency-modulated continuous wave within the N frequency-modulated continuous waves.

3. The method as described in claim 1, characterized in that, The frequency domain position includes the start frequency and / or the center frequency, and the time domain position includes the start time and / or the center time.

4. The method as described in claim 2, characterized in that, The frequency domain position includes the start frequency and / or the center frequency, and the time domain position includes the start time and / or the center time.

5. The method according to any one of claims 1-4, characterized in that, ； in, , The time-domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The duration of each of the N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

6. A signal receiving method, characterized in that, include: Receive a second frequency-modulated continuous wave sequence, wherein the second frequency-modulated continuous wave sequence is a signal formed by the first frequency-modulated continuous wave sequence after being transmitted by the first device and then propagated through space and reflected by the target; Information about the target is determined based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence, the information including distance and / or velocity; The first frequency-modulated continuous wave sequence includes N frequency-modulated continuous waves, where N is an integer greater than or equal to 1, and the product of the time-domain position and the corresponding frequency-domain position of the first frequency-modulated continuous wave among the N frequency-modulated continuous waves satisfies a first condition; The first condition includes: ； Where n is the index of the frequency-modulated continuous wave among the N frequency-modulated continuous waves. ; The time-domain position of the frequency-modulated continuous wave with index n among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index n among the N frequency-modulated continuous waves; , These are the preset frequency hopping parameters; The frequency domain positions of the N frequency-modulated continuous waves are evenly distributed in the frequency domain, and the interval between the frequency domain positions of two adjacent frequency-modulated continuous waves is a fixed value. ; ； ； in, The time-domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The duration of each of the N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

7. The method as described in claim 6, characterized in that, The first condition is related to the position of the first frequency-modulated continuous wave within the N frequency-modulated continuous waves.

8. The method as described in claim 6, characterized in that, The frequency domain position includes the start frequency and / or the center frequency, and the time domain position includes the start time and / or the center time.

9. The method as described in claim 7, characterized in that, The frequency domain position includes the start frequency and / or the center frequency, and the time domain position includes the start time and / or the center time.

10. The method according to any one of claims 6-9, characterized in that, ； in, , The time-domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The duration of each of the N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

11. The method according to any one of claims 6-9, characterized in that, Determining the velocity of the target based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence includes: The intermediate frequency signal sequence is determined based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence; The intermediate frequency signal sequence is processed using Fast Fourier Transform (FFT).

12. The method as described in claim 10, characterized in that, Determining the velocity of the target based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence includes: The intermediate frequency signal sequence is determined based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence; The intermediate frequency signal sequence is processed using Fast Fourier Transform (FFT).

13. The method as described in claim 11, characterized in that, Before processing the intermediate frequency signal sequence using FFT, the method further includes: Phase compensation is performed on the second frequency-modulated continuous wave sequence or the intermediate frequency signal sequence based on the interval of the frequency domain positions of the N frequency-modulated continuous waves.

14. The method as described in claim 12, characterized in that, Before processing the intermediate frequency signal sequence using FFT, the method further includes: Phase compensation is performed on the second frequency-modulated continuous wave sequence or the intermediate frequency signal sequence based on the interval of the frequency domain positions of the N frequency-modulated continuous waves.

15. A signal transmitting device, characterized in that, include: Processing unit, used to generate a first frequency-modulated continuous wave sequence; A transmitting unit is configured to transmit the first frequency-modulated continuous wave sequence, the first frequency-modulated continuous wave sequence comprising N frequency-modulated continuous waves, wherein N is an integer greater than or equal to 1; Among the N frequency-modulated continuous waves, the product of the time-domain position and the corresponding frequency-domain position within the first frequency-modulated continuous wave satisfies the first condition; The first condition includes: ； Where n is the index of the frequency-modulated continuous wave among the N frequency-modulated continuous waves. ; The time-domain position of the frequency-modulated continuous wave with index n among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index n among the N frequency-modulated continuous waves; , These are the preset frequency hopping parameters; The frequency domain positions of the N frequency-modulated continuous waves are evenly distributed in the frequency domain, and the interval between the frequency domain positions of two adjacent frequency-modulated continuous waves is a fixed value. ; ； ； in, The time-domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The duration of each of the N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

16. The apparatus as claimed in claim 15, characterized in that, The first condition is related to the position of the first frequency-modulated continuous wave within the N frequency-modulated continuous waves.

17. The apparatus as claimed in claim 15, characterized in that, The frequency domain position includes the start frequency and / or the center frequency, and the time domain position includes the start time and / or the center time.

18. The apparatus as claimed in claim 16, characterized in that, The frequency domain position includes the start frequency and / or the center frequency, and the time domain position includes the start time and / or the center time.

19. The apparatus according to any one of claims 15-18, characterized in that, ； in, , The time-domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The duration of each of the N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

20. A signal receiving device, characterized in that, include: The receiving unit is used to receive a second frequency-modulated continuous wave sequence, wherein the second frequency-modulated continuous wave sequence is a signal formed by the first frequency-modulated continuous wave sequence after being transmitted by the first device and then propagating through space and being reflected by the target; Processing unit, configured to determine information about the target based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence, the information including velocity and / or distance; The first frequency-modulated continuous wave sequence includes N frequency-modulated continuous waves, where N is an integer greater than or equal to 1, and the product of the time-domain position and the corresponding frequency-domain position of the first frequency-modulated continuous wave among the N frequency-modulated continuous waves satisfies a first condition; The first condition includes: ； Where n is the index of the frequency-modulated continuous wave among the N frequency-modulated continuous waves. ; The time-domain position of the frequency-modulated continuous wave with index n among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index n among the N frequency-modulated continuous waves; , These are the preset frequency hopping parameters; The frequency domain positions of the N frequency-modulated continuous waves are evenly distributed in the frequency domain, and the interval between the frequency domain positions of two adjacent frequency-modulated continuous waves is a fixed value. ; ； ； in, The time-domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The duration of each of the N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

21. The apparatus as claimed in claim 20, characterized in that, The first condition is related to the position of the first frequency-modulated continuous wave within the N frequency-modulated continuous waves.

22. The apparatus as claimed in claim 20, characterized in that, The frequency domain position includes the start frequency and / or the center frequency, and the time domain position includes the start time and / or the center time.

23. The apparatus as claimed in claim 21, characterized in that, The frequency domain position includes the start frequency and / or the center frequency, and the time domain position includes the start time and / or the center time.

24. The apparatus according to any one of claims 20-23, characterized in that, ； in, , The time-domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The frequency domain position of the frequency-modulated continuous wave with index 0 among the N frequency-modulated continuous waves; The duration of each of the N frequency-modulated continuous waves, wherein the durations of the N frequency-modulated continuous waves are the same.

25. The apparatus according to any one of claims 20-23, characterized in that, The processing unit is specifically used for: The intermediate frequency signal sequence is determined based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence; The intermediate frequency signal sequence is processed using Fast Fourier Transform (FFT).

26. The apparatus as claimed in claim 24, characterized in that, The processing unit is specifically used for: The intermediate frequency signal sequence is determined based on the second frequency-modulated continuous wave sequence and the first frequency-modulated continuous wave sequence; The intermediate frequency signal sequence is processed using Fast Fourier Transform (FFT).

27. The apparatus as claimed in claim 25, characterized in that, The processing unit is also used for: Before processing the intermediate frequency signal sequence using FFT, phase compensation is performed on the second frequency-modulated continuous wave sequence or the intermediate frequency signal sequence according to the interval of the frequency domain positions of the N frequency-modulated continuous waves.

28. The apparatus as claimed in claim 26, characterized in that, The processing unit is also used for: Before processing the intermediate frequency signal sequence using FFT, phase compensation is performed on the second frequency-modulated continuous wave sequence or the intermediate frequency signal sequence according to the interval of the frequency domain positions of the N frequency-modulated continuous waves.

29. A terminal device, characterized in that, Includes the device as described in any one of claims 15-19 and / or the device as described in any one of claims 20-28.

30. A computer-readable storage medium, characterized in that, The readable storage medium is used to store instructions that, when executed, cause the method as described in any one of claims 1-14 to be implemented.

31. A computer program product, characterized in that, The computer program product stores instructions that, when run on a computer, cause the computer to perform the method as described in any one of claims 1-14.

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