Method and system for time-frequency-code sensor coding for interference suppression in vehicle

Abstract

The invention relates to a time-frequency-code sensor coding method and system for interference suppression in a vehicle. A system and method for time-frequency coding with code division multiple access (CDMA) for interference mitigation for vehicle sensors includes generating, by a first sensor, a first chirp signal in a first channel and transmitting, from a vehicle, and generating, by a second sensor, a second chirp signal in a second channel and transmitting. Both the first channel and the second channel include a time channel component, a frequency channel component, and a code dimension. The first sensor receives a first reflected signal and the second sensor receives a second reflected signal, the first and second reflected signals each coming from one or more objects. Further, the second channel includes one or more different time channels, different frequency channels, or different code dimensions relative to the first channel, and the code dimension of the first channel and the code dimension of the second channel are determined from a set of code dimensions based on the lowest interference noise estimate.

Description

TECHNICAL FIELD

[0001] Vehicles are rapidly integrating more and more technology components into their systems. Special purpose microcontrollers, technologies, and sensors can be used in many different applications in a vehicle. Automotive microcontrollers and sensors can be used to enhance the automation architecture that provides the most advanced experience and service to customers, for example, in tasks such as body control, camera vision, information display, safety, autonomous control, and the like. Further, functions such as adaptive cruise control, lane change assist, and vehicle proximity detection can use a variety of sensors that use light detection and ranging (LIDAR), radio detection and ranging (RADAR), ultrasound, and other wireless technologies to implement their functions. BACKGROUND

[0002] However, as the large-scale use of such wireless detection and communication sensors, the potential for interference between various vehicles and their systems is ever increasing. Thus, the ability to suppress interference so that vehicle systems can operate successfully is critical. SUMMARY

[0003] Disclosed herein is a vehicle system and method for interference suppression for vehicle sensors utilizing code division multiple access (CDMA) for time-frequency encoding. As disclosed herein, a sensor can include components configured to transmit multiple signals simultaneously or overlapping in time, while also configured to receive multiple concurrent signals. Further, a single sensor or sensor assembly can include multiple sensors each having the ability to generate, transmit, and receive signals.

[0004] Thus, a system for interference suppression for vehicle sensors utilizing CDMA for time-frequency encoding can include one or more sensors, where for example a first sensor located within a vehicle can be used to generate and transmit a first chirp signal. The first chirp signal can be transmitted in a first channel, where the first channel includes a time channel, a frequency channel, and a code dimension. The first sensor can also receive first reflected signals from one or more objects from the first chirp signal. Further, a second sensor can generate and transmit a second chirp signal in a second channel, where the second channel can include a time channel, a frequency channel, and a code dimension, where the sensor can also receive second reflected signals from one or more objects from the second chirp signal. Further, the second channel can be composed of one or more different time channels, different frequency channels, or different code dimensions relative to the first channel. Further, the code dimension of the first channel and the code dimension of the second channel can be determined from a set of code dimensions based on a lowest interference noise estimate.

[0005] Another aspect of the disclosure can include a third sensor that can be used to generate a waveform distributed across multiple time-frequency channels.

[0006] In another aspect of the disclosure, the second sensor can enter a listening mode to determine an interference noise estimate for each code dimension in the set of code dimensions.

[0007] In another aspect of the disclosure, the first sensor and the second sensor are time synchronized.

[0008] In another aspect of the disclosure, the first code dimension is semi-orthogonal to a second code dimension in the set of code dimensions.

[0009] In another aspect of the disclosure, the processing logic is to determine a noise level of the first reflected signal, wherein the noise level is stored in a memory including a time decay mechanism.

[0010] In another aspect of the disclosure, the first sensor can generate a subsequent chirp signal in a third channel when the noise level is greater than a threshold value.

[0011] In another aspect of the disclosure, the current channel can be classified as occupied when the noise level is greater than a threshold level.

[0012] In another aspect of the disclosure, the first sensor and the second sensor can not transmit on an occupied frequency channel.

[0013] Another aspect of the disclosure can also include processing logic to perform a first noise estimate based on a range Fast Fourier Transform (FFT) and a Doppler FFT prior to digitally beamforming the first reflected signal, and to perform a second noise estimate based on a range Fast Fourier Transform (FFT) prior to a Doppler FFT of the first reflected signal.

[0014] In another aspect of the disclosure, the second sensor is not located in the vehicle.

[0015] In another aspect of the disclosure, the first sensor and the second sensor utilize radar, lidar, or ultrasonic frequencies.

[0016] Another aspect of the present disclosure can include a method for time-frequency coding with CDMA for interference mitigation for vehicle sensors. Such a method can include generating and transmitting, by a first sensor, a first chirp signal in a first channel from a vehicle, where the first channel can include a time channel, a frequency channel, and a code dimension. The method can also include generating and transmitting, by a second sensor, a second chirp signal in a second channel, where the second channel can include a time channel, a frequency channel, and a code dimension. The method can also include receiving, by the first sensor, a first reflected signal from one or more objects from the first chirp signal, and also receiving, by the second sensor, a second reflected signal from one or more objects from the second chirp signal. However, the second channel can include one or more different time channels, different frequency channels, or different code dimensions relative to the first channel, and where the code dimension of the first channel and the code dimension of the second channel can be determined from a set of code dimensions based on a lowest interference noise estimate.

[0017] Another aspect of the present disclosure can include listening, by the second sensor, to determine an interference noise estimate for each code dimension in the set of code dimensions.

[0018] Another aspect of the present disclosure can include time synchronizing the first sensor and the second sensor.

[0019] Another aspect of the present disclosure can include where the first code dimension is semi-orthogonal to a second code dimension in the set of code dimensions.

[0020] Another aspect of the present disclosure can include determining, by processing logic, a noise level of the first reflected signal, where the noise level can be stored in a memory including a time decay mechanism.

[0021] Another aspect of the present disclosure can include classifying a current time-frequency channel as occupied when the noise level is greater than a threshold level.

[0022] Another aspect of the present disclosure can include performing a first noise estimate based on a range Fast Fourier Transform (FFT) and a Doppler FFT prior to digitally beamforming the first reflected signal, and also can perform a second noise estimate based on a range Fast Fourier Transform (FFT) prior to a Doppler FFT of the first reflected signal.

[0023] Another aspect of the present disclosure can include where the first sensor and the second sensor can not transmit on an occupied frequency channel.

[0024] Another aspect of the present disclosure can include where the first sensor and the second sensor can utilize radar, lidar, or ultrasonic frequency usage.

[0025] Another aspect of this disclosure may include a method for time-frequency coding using CDMA for interference suppression of vehicle sensors, the method comprising generating and transmitting a first chirped signal from a vehicle in a first channel by a first sensor, wherein the first channel may include a time channel, a frequency channel, and a code dimension. The method may further include generating and transmitting a second chirped signal in a second channel by a second sensor, wherein the second channel may include a time channel, a frequency channel, and a code dimension. The method may include receiving a first reflected signal from one or more objects from the first chirped signal by the first sensor, and may further include receiving a second reflected signal from one or more objects from the second chirped signal by the second sensor. The method may include monitoring by the second sensor to determine an interference noise estimate for each of the set of code dimensions, and may further include determining a noise level of the first reflected signal by processing logic, wherein the noise level is stored in a memory including a time decay mechanism. The method may further include performing a first noise estimate based on a range fast Fourier transform (FFT) and a Doppler FFT prior to digital beamforming of the first reflected signal, and may further include performing a second noise estimate based on a range fast Fourier transform (FFT) prior to performing a Doppler FFT on the first reflected signal. The method may include a second channel that may include one or more different time channels, different frequency channels, or different code dimensions relative to the first channel, and wherein the code dimensions of the first channel and the code dimensions of the second channel may be determined from a set of code dimensions based on a minimum interference noise estimate.

[0026] The present invention provides the following technical solutions.

[0027] Technical Solution 1. A system for time-frequency coding using Code Division Multiple Access (CDMA) for interference suppression of vehicle sensors, comprising:

[0028] A first sensor in the vehicle is configured to: generate and transmit a first chirped signal in a first channel, and receive a first reflected signal from one or more objects from the first chirped signal, wherein the first channel includes a time channel, a frequency channel, and a code dimension; and

[0029] A second sensor is configured to: generate and transmit a second chirped signal in a second channel, and receive a second reflected signal from one or more objects from the second chirped signal, wherein the second channel includes a time channel, a frequency channel, and a code dimension;

[0030] The second channel includes one or more different time channels, different frequency channels, or different code dimensions relative to the first channel, and

[0031] The code dimension of the first channel and the code dimension of the second channel are determined from a set of code dimensions based on the lowest interference noise estimation.

[0032] Technical Solution 2. The system according to Technical Solution 1, wherein the second sensor is configured to enter a listening mode to determine an estimate of interference noise for each code dimension in the set of code dimensions.

[0033] Technical solution 3. The system according to technical solution 1, wherein the first sensor and the second sensor are time-synchronized.

[0034] Technical Solution 4. The system according to Technical Solution 1, wherein the first code dimension is semi-orthogonal to the second code dimension in the group of code dimensions.

[0035] Technical Solution 5. The system according to Technical Solution 1 further includes processing logic for determining the noise level of the first reflected signal, wherein the noise level is stored in a memory including a time decay mechanism.

[0036] Technical Solution 6. The system according to Technical Solution 5, wherein when the noise level is greater than a threshold, the first sensor is configured to generate a subsequent chirped signal in the third channel.

[0037] Technical Solution 7. The system according to Technical Solution 1, wherein when the noise level is greater than the threshold level, the current channel is classified as occupied.

[0038] Technical Solution 8. The system according to Technical Solution 1, wherein the first sensor and the second sensor are configured not to transmit on an occupied frequency channel.

[0039] Technical Solution 9. The system according to Technical Solution 1 further includes processing logic, which is used to perform a first noise estimation based on range fast Fourier transform (FFT) and Doppler FFT before performing digital beamforming on the first reflected signal, and to perform a second noise estimation based on the range fast Fourier transform (FFT) before performing Doppler FFT on the first reflected signal.

[0040] Technical Solution 10. The system according to Technical Solution 1, wherein the second sensor is not located in the vehicle.

[0041] Technical Solution 11. The system according to Technical Solution 1, wherein the first sensor and the second sensor utilize radar, lidar, or ultrasonic frequencies.

[0042] Technical Solution 12. A method for time-frequency coding using Code Division Multiple Access (CDMA) for interference suppression of vehicle sensors, comprising:

[0043] A first chirp signal is generated by a first sensor in a first channel and transmitted from the vehicle, wherein the first channel includes a time channel, a frequency channel, and a code dimension;

[0044] A second chirp signal is generated and transmitted by a second sensor in a second channel, wherein the second channel includes a time channel, a frequency channel, and a code dimension;

[0045] The first sensor receives a first reflected signal from one or more objects from the first chirp signal; and

[0046] The second sensor receives a second reflected signal from one or more objects from the second chirp signal;

[0047] The second channel includes one or more different time channels, different frequency channels, or different code dimensions relative to the first channel, and

[0048] The code dimension of the first channel and the code dimension of the second channel are determined from a set of code dimensions based on the lowest interference noise estimation.

[0049] Technical Solution 13. The method according to Technical Solution 12 further includes using the second sensor to monitor and determine an estimate of interference noise for each code dimension in the set of code dimensions.

[0050] Technical solution 14. The method according to technical solution 12 further includes synchronizing the time of the first sensor and the second sensor.

[0051] Technical Solution 15. The method according to Technical Solution 12, wherein the first code dimension is semi-orthogonal to the second code dimension in the group of code dimensions.

[0052] Technical Solution 16. The method according to Technical Solution 12 further includes determining the noise level of the first reflected signal by processing logic, wherein the noise level is stored in a memory including a time decay mechanism.

[0053] Technical Solution 17. The method according to Technical Solution 12 further includes: performing a first noise estimation based on a range fast Fourier transform (FFT) and a Doppler FFT before performing digital beamforming on the first reflected signal; and performing a second noise estimation based on the range fast Fourier transform (FFT) before performing a Doppler FFT on the first reflected signal.

[0054] Technical Solution 18. The method according to Technical Solution 12, wherein the first sensor and the second sensor are configured not to transmit on an occupied frequency channel.

[0055] Technical Solution 19. The method according to Technical Solution 12, wherein the first sensor and the second sensor utilize radar, lidar, or ultrasonic frequencies.

[0056] Technical Solution 20. A method for time-frequency coding using Code Division Multiple Access (CDMA) for interference suppression of vehicle sensors, comprising:

[0057] A first chirp signal is generated by a first sensor in a first channel and transmitted from the vehicle, wherein the first channel includes a time channel, a frequency channel, and a code dimension;

[0058] A second chirp signal is generated and transmitted by a second sensor in a second channel, wherein the second channel includes a time channel, a frequency channel, and a code dimension;

[0059] The first sensor receives a first reflected signal from one or more objects from the first chirp signal;

[0060] The second sensor receives a second reflected signal from one or more objects from the second chirp signal;

[0061] The second sensor monitors and determines the interference noise estimate for each code dimension in the set of code dimensions;

[0062] The noise level of the first reflected signal is determined by processing logic, wherein the noise level is stored in a memory including a time decay mechanism; and

[0063] A first noise estimation is performed based on the range fast Fourier transform (FFT) and the Doppler FFT before digital beamforming is applied to the first reflected signal; and a second noise estimation is performed based on the range fast Fourier transform (FFT) before the Doppler FFT is applied to the first reflected signal.

[0064] The second channel includes one or more different time channels, different frequency channels, or different code dimensions relative to the first channel, and

[0065] The code dimension of the first channel and the code dimension of the second channel are determined from a set of code dimensions based on the lowest interference noise estimation.

[0066] The foregoing features and advantages of this disclosure, as well as other features and accompanying advantages, will become apparent from the following detailed description of illustrative examples and models used to carry out this disclosure, when taken in conjunction with the accompanying drawings and appended claims. Furthermore, this disclosure expressly includes combinations and sub-combinations of the elements and features presented above and below. Attached Figure Description

[0067] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate implementations of this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0068] Figure 1A and Figure 1B This is an illustration of a multi-vehicle situation with interfering sensor signals, based on the present disclosure.

[0069] Figure 2 This is an illustration of a multi-zone vehicle sensor interference scenario based on this disclosure.

[0070] Figure 3 This is a diagram of a time-frequency sensor system with CDMA configuration according to this disclosure.

[0071] Figure 4 This is a diagram of a time-frequency coded sensor channel according to this disclosure.

[0072] Figure 5 This is a diagram illustrating the code margin of linear frequency modulation according to this disclosure.

[0073] Figure 6 This is a diagram illustrating the multi-time-frequency channel waveforms according to this disclosure.

[0074] Figure 7 It is a diagram of a noisy multi-time-frequency plot according to the present disclosure.

[0075] Figure 8 This is a diagram illustrating the codeword monitoring mode in use according to this disclosure.

[0076] Figure 9 A flowchart is depicted for a method according to this disclosure for time-frequency coding using CDMA for interference suppression of sensors.

[0077] The accompanying drawings are not necessarily drawn to scale and may present slightly simplified representations of the various preferred features disclosed herein, including, for example, specific dimensions, orientations, positions, and shapes. Details associated with such features will be determined in part by the specific intended application and environment of use. Detailed Implementation

[0078] This disclosure allows for numerous different forms of embodiments. Representative examples of this disclosure are shown in the accompanying drawings and are described in detail herein as non-limiting examples of the disclosed principles. Therefore, elements and limitations described in the abstract, introduction, summary, and detailed description sections but not expressly set forth in the claims should not be incorporated into the claims, alone or in combination, by implication, inference, or otherwise.

[0079] For the purposes of this specification, unless otherwise stated, the use of the singular includes the plural, and vice versa; the terms “and” and “or” should be conjunction and disjunctive; and the words “including,” “contains,” “comprising,” “containing,” “having,” etc., should mean “including, but not limited to.” Furthermore, approximate words such as “about,” “almost,” “substantially,” “largely,” “approximately,” etc., may be used herein in the sense of “being, near, or almost being,” or “within 0-5% of,” or “within acceptable manufacturing tolerances,” or logical combinations thereof. As used herein, a component “configured” to perform a specified function is capable of performing the specified function without alteration, rather than merely having the potential to perform the specified function after further modification. In other words, when explicitly configured to perform a specified function, the described hardware is specifically selected, created, implemented, utilized, programmed, and / or designed for the purpose of performing the specified function.

[0080] Referring to the accompanying drawings, the leftmost number of the reference numerals indicates the drawing in which the reference numeral first appears (e.g., reference numeral "310" indicates that the element numbered this way was first labeled or first appeared). Figure 3 (in Chinese). Additionally, elements with the same reference numerals following different letters in the alphabet or other unique markings (e.g., apostrophes) indicate elements that may be identical in structure, operation, or form but may be identified as being in different locations in space or repeating at different points in time (e.g., reference numerals "110a" and "110b" may indicate two different input devices that may be functionally identical but located at different points in the simulated scene).

[0081] Autonomous vehicle and advanced driver assistance systems (AV / ADAS) such as adaptive cruise control, automatic parking, automatic brake hold, automatic braking, evasive steering assist, lane keeping assist, adaptive headlights, reversing assist, blind spot detection, cross traffic alert, local hazard warning, and rear automatic braking can rely on information obtained from cameras and sensors on the vehicle. As these types of features become increasingly prevalent in vehicles, the sensors upon which these features rely are susceptible to radiated interference from other vehicles. This interference can lead to false alarms or masking of real targets, which in turn can degrade the performance of systems that depend on sensor information. The severity of interference in sensors can also vary with the number of sensors in a given area. Therefore, as AV / ADAS systems become more widespread, the sensors within each vehicle become mission-critical components requiring high reliability.

[0082] Figure 1A and Figure 1B These are illustrations of multi-vehicle scenarios 100 and 100' with possible interference with sensor signals, according to embodiments of this disclosure. Figure 1A In this scenario, the victim vehicle 110 is emitting or transmitting a radiation signal 115 (e.g., radar, lidar, or ultrasound) towards the target vehicle 120. However, the oncoming vehicle 130 may also be equipped with transmitting sensors and therefore may also emit a radiation signal 135. Therefore, an interference zone 150 may exist where the victim vehicle 110 may receive the radiation signal 135 instead of the expected reflected signal from the target vehicle 120's radiation signal 115. Such interference can lead to erroneous readings and may render the expected reflected signal completely invalid. Figure 1B The illustration depicts a comparable scenario where the victim vehicle 110 may receive radiated signal 145 from adjacent vehicle 140, thus creating an interference area 160. Sensors can operate at multiple frequencies or frequency ranges, and therefore, especially if radiated signal 115 and radiated signal 135 or radiated signal 145 operate at the same or similar frequencies, the resulting interference can produce highly undesirable results.

[0083] Sensor signals (e.g., radiation signal 115) can be generated as multiple chirped signals. A chirped signal can be defined as a signal in which the frequency increases (e.g., upper chirp) or decreases (lower chirp) over time. In some embodiments, the term "chirp" can be used interchangeably with swept frequency signals and can be applied to sonar, radar, and laser systems, and can also be used in spread spectrum communications.

[0084] Figure 2This is an illustration of a multi-zone vehicle interference scenario 200 according to an embodiment of the present disclosure. Scenario 200 can be envisioned where vehicle 210 may be surrounded by many other vehicles. These other vehicles 215 can be categorized into those vehicles close to vehicle 210 within the inner zone 220 and another group of vehicles 225 further away from vehicle 210 within the outer zone 230. The vehicles 215 within the inner zone 220 (vehicles within the inner zone 220 can be collectively referred to as vehicles 215) may also be equipped with transmitting sensors, and due to their proximity to vehicle 210, vehicle 210 is a receiver of many relatively strong radiated signals emitted from vehicle 215. However, although these received radiated signals may be relatively strong, there may be far fewer vehicles compared to the number of vehicles 225 within the outer zone 230 (vehicles within the outer zone 230 can be collectively referred to as vehicles 225). To suppress interference between vehicle 210 and inner zone vehicle 215, the use of time-frequency sensor coding as described in U.S. Patent Publication No. 2024 / 0201319 entitled “Method and System of Time-Frequency Sensor Coding for Interference Mitigation in a Vehicle”, which is incorporated herein by reference in its entirety, can provide an optimal solution for interference suppression.

[0085] However, compared to the area in inner zone 220, the area in outer zone 230 may have the potential to contain a much larger number of vehicles capable of radiating signals compared to the number of vehicles in inner zone 220. While vehicle 210 may be physically farther from outer zone 230 and therefore the signal received from vehicles in outer zone 230 may be slightly weaker, there is still a possibility of receiving a large number of signals from vehicles in outer zone 230, and therefore a potential increase in signal interference levels. In such a scenario, limiting interference suppression to time-frequency sensor coding may not provide an optimal number of available channels to accommodate the number of vehicles 225 in outer zone 230. Therefore, this disclosure relates to using CDMA with time-frequency sensor coding to utilize an additional number of channels to suppress interference. The number of channels in a time-frequency coding scheme can be extended by combining orthogonal signal coding, thereby generating time-frequency-code channels.

[0086] Such encoding can include intra-pulse encoding on monotonic and injective frequency modulation frequency functions, such as linear frequency modulation (LFM) on phase, frequency, or hybrid encoding. While the time-frequency dimension can be completely orthogonal, the code dimension can include semi-orthogonality.

[0087] Figure 3This is an illustration of a possible processing flow 300 for a CDMA-based time-frequency sensor system according to an embodiment of this disclosure. Processing flow 300 may include a channel definition component 310, a desired channel calculation component 315, a codeword library 320, a channel hopping component 340, a listening mode component 345, an interference noise estimation component 350, a codeword selection component 355, and a time source GNSS 363 (Global Navigation Satellite System) component. Furthermore, processing flow 300 may include a transmit channel 360 for signal transmission, a transmit component 365, and a transmit antenna 370 for transmitting or broadcasting a waveform signal 372. The waveform signal 372 can then be reflected from an object (e.g., a target vehicle 323) and returned as a reflected signal 324. On the receiving side, processing flow 300 may also include a receive antenna 325, a signal processing component 330, and a noise estimation component 335.

[0088] Processing flow 300 may involve defining and customizing time-frequency coded channels based on the frequency modulation of the signal, thereby enabling the overlapping transmission of multiple signals and increasing the number of time channels while maintaining orthogonality. Furthermore, processing flow 300 can suppress channel collisions through interference estimation and channel hopping. Additionally, in some embodiments, each sensor is assigned to a frequency channel, thus avoiding interference from other channels. A more detailed explanation of each component follows.

[0089] Processing flow 300 may begin with channel limitation 310, where channel limitation may include time components, frequency components, and semi-orthogonal code dimension channel components. Processing flow 300 may include a time-frequency coding scheme, which can be modified to incorporate coding by transmitting coded signals. For example, after a time-frequency channel hopping initiated by high noise level or interference detection, the new time-frequency channel undergoes listening to find existing codewords. Codewords can then be selected for transmission by the sensor based on the code channel with the lowest noise.

[0090] The channel limiting component 310 can involve the efficient limiting of a channel based on specific characteristics of the waveform being used, thereby enabling time-efficient channel allocation. According to embodiments of this disclosure, in Figure 4 The diagram illustrates the channel defining component 310, which shows a time-frequency channel 400. Channel 400 is shown as depicted on a vertical frequency axis 410 and a horizontal time axis 420. Channel 400 may also include a waveform, illustrated here as a chirped signal 430, having a chirped duration T. c With bandwidth B c And the chirping slope α = B c / T c Channel 400 also illustrates four other time components of the possible channel, such as signal reception time or signal reception window, calculated as B. f / α is marked as receiving time 435, propagation time 445, synchronization margin 455, and code margin 460.

[0091] The channel can be defined, assuming the linear frequency modulation (LFM) signal has a chirp duration T. c Bandwidth B c And the chirping slope α = B c / T c And the pulse repetition interval (PRI) is T. R Each signal can be transmitted in its own time slot, which can be defined by the duration of the signal; in other words, it does not overlap with another signal in time. Processing flow 300 can utilize different time channel codings, taking into account the hardware reception time B inserted into the sensor. f In the low-pass filter of / α, the receiving frequency window can be varied during the chirp duration by mixing the received signal with a reference signal; this process can be called stretching. This is in addition to the maximum propagation delay between the two most distant correlated signal sources (e.g., radar) (classified as τ). max In addition to the time synchronization accuracy classified as δ, there is also an additional code margin due to the increased instantaneous bandwidth caused by the additional transmitted codewords.

[0092] In addition, the low-pass filter can be made by B f Limited, its filtering is higher than B. f The frequency offset can be defined as the sampling frequency.

[0093] Therefore, the following equation defines the starting point of the nth time channel:

[0094]

[0095] Furthermore, the maximum propagation delay can then be limited based on the required attenuation between signal sources as follows:

[0096]

[0097] Where A[dB] can be the desired attenuation.

[0098] Furthermore, the entire automotive radar spectrum can be utilized to allow for additional transmission channels as shown below:

[0099] f k =f0+αT c k

[0100] Here, f0 is the starting point of the allocated spectrum, and it is constrained by the allocated spectrum span. The total number of channels can be limited to the number of time channels multiplied by the number of frequency channels. Furthermore, as each time-frequency channel, an additional N can be transmitted. cCodewords. Therefore, the total number of channels can be limited to the number of time channels multiplied by the number of frequency channels multiplied by the number of codewords.

[0101] Figure 5 This is an example of code margin in LFM according to embodiments of the present disclosure. Figure 5 Example code margin 535 is included, which plots the time of the horizontal axis 520 relative to the frequency of the vertical axis 510.

[0102] Figure 6 The diagram illustrates a waveform 600 spanning five time channels and two frequency channels according to an embodiment of the present disclosure. The graph illustrates the relationship between the frequency of the signal on the vertical frequency axis 610 and the time on the horizontal time axis 620. The required channel calculations can be performed using parameters including slope α and chirp duration T. c Channel time length T channel and channel bandwidth BW channel The parameters are used to define a specific waveform.

[0103] As an example, for a slope of α r The chirping duration is T. (Cr) For LFM radars with different waveforms, the required frequency and time channels can be defined as follows:

[0104] If α r <α:

[0105]

[0106] If α r >α:

[0107]

[0108] i indicates the frequency channel, j indicates the time channel, and the initial channel is i=0, j=0.

[0109] The number of channels used is:

[0110]

[0111] Next, the codeword library 320 can contain available codewords. Furthermore, the orthogonality of the codewords may also be affected by the number of codewords used. For example, an adaptive codeword library can be used, where the number of available codewords varies with the number of operating radars in the time-frequency channel. Therefore, the orthogonality of the codewords can be the same for all codewords in the channel.

[0112] Next, signal processing 330 can be applied to cases where the transmitting component 365 is a waveform signal, which can then be transmitted or broadcast as waveform signal 372 via transmitting antenna 370. Waveform signal 372 can then be reflected from an object (e.g., target vehicle 323) and returned as reflected signal 324, which is received by receiving antenna 325. The received reflected signal 324 can then be processed by signal processing 330. Signal processing 330 (which may also be referred to as radar processing) can be performed based on range fast Fourier transform (FFT), Doppler FFT, and digital beamforming.

[0113] Furthermore, the noise estimation 335 component can estimate the noise level for each distance of the channel using two methods based on the following formula after distance processing:

[0114]

[0115] Noise2 = argmax k,n,h |RTC[k,n,h]|-|RTC[k,b-1,h]|

[0116] RDC[k,l,h] can be a cube of signal data after the range FFT and Doppler FFT but before digital beamforming, and it has a range dimension k, a Doppler dimension l, and a channel dimension h.

[0117] H, L, and K can represent the number of samples in the range dimension, Doppler dimension, and channel dimension, respectively. Noise2 can take advantage of the fact that the interference source is not perfectly time-synchronized and may not appear in every chirp. In addition, the diff function can search for and detect high energy differences caused by interference variations. RTC[k,n,h] can represent the cube of signal data after the range FFT but before the Doppler FFT.

[0118] After signal processing 330 and noise estimation 335, the channel hopping 340 component can use the noise data estimated by noise estimation 335 to determine a new time-frequency-code channel. According to embodiments of this disclosure, in Figure 7 The diagram illustrates an example of a channel management map 700. Figure 7 The diagram illustrates the relationship between the frequency channel on the vertical frequency axis 710 and the time channel on the horizontal time axis 720. For example, Figure 7 The illustration shows that time channel 0 can have minimal noise on the frequency channels shown, compared to a threshold. In contrast, time channel 1 can indicate noise levels above the threshold on frequency channels 0 and 2.

[0119] The channel hopping 340 component can determine that a particular transmission frequency channel may have an estimated noise level higher than a predetermined threshold based on the fact that the Noise1 and Noise2 data it receives exceed a certain threshold, and therefore the particular frequency channel can be classified as occupied.

[0120] Noise1 = Threshold1

[0121] Noise2 = Threshold2

[0122] Furthermore, the associated noise levels can be stored in memory, summing the noise measurement results Noise1 and Noise2. The current channel can be defined as discussed with respect to the channel definition component 310. The channel switching component 340 can label multiple channels according to the noise levels correspondingly determined by the required channel calculation component 315.

[0123] For example, a new frequency channel in the next time channel can be randomly selected from available frequency channels (e.g., a marked frequency channel that is not occupied). However, in an embodiment, if a frequency channel is occupied, the channel hopping 340 component can select a frequency channel with the lowest noise level determined in the desired channel calculation 315 component. Furthermore, the noise level in a particular frequency channel can change over time. Therefore, a noise level attenuation factor (e.g., β) can be applied. Figure 7 The mapping is 700, and can be performed for each new frame in the waveform transport stream. Therefore, Map = β·Map. For a waveform consisting of multiple time-frequency channels, multiple channels can be selected in such a way that the selected channels are not occupied. If such a channel span is not available, the channel span with the lowest average noise can be selected.

[0124] Next, the listening mode 345 component involves, for example, listening to codewords already in use as specified by the codeword library 320 using a radar sensor. Figure 8This is an illustration of a monitoring mode 800 for a codeword in use according to an embodiment of the present disclosure. The monitoring mode 345 component can utilize a passive mode, where a frame of M pulses can be divided into N interleaved subframes, i.e., the total number of codewords in the library, which are shown as sample pulses 810 to 830. Furthermore, each subframe can be matched with a different codeword, and these codewords are then passed through correlators, shown as correlators 815 for code #1 to 835 for code #N. Each codeword can then be combined with an associated noise estimate (e.g., noise estimate 820 associated with codeword #1 to noise estimate 840 associated with codeword N). Then, for each codeword, if the maximum value of a particular codeword and noise exceeds a predetermined threshold, the codeword can be determined to be in use. The in-use state can be shown as code #1 indicator 825 to code #N indicator 845.

[0125] Next, the interference noise estimation component 350 can estimate the number of codewords used in a specific channel and select the best available codewords. The selected codewords are estimated to meet the expected performance. However, if the actual performance is lower than expected, codewords from the next family (i.e., with a larger number of transmitting radars) can be selected. Such a method of estimating code noise can incorporate the effects of different orthogonality levels between codewords.

[0126] The codeword selection 355 component can include an estimate of the noise level for each codeword after distance processing, which can be estimated using the following formula:

[0127] Noise codeword =max|RTC[k,codeword:N,M,h]|

[0128] Furthermore, if the interference sources are matched in monitoring mode, the peak value will indicate the occupancy of the code channel. And, if the code channel is occupied, a new codeword with minimal noise can be selected.

[0129] Next, the transmission channel 360 component can store the transmitted channel information. In an embodiment, the initial transmission channel can be randomly selected. However, the transmission channel may also change due to feedback information from the channel hopping 340 component. The transmission 365 component can generate a transmission signal based on the corresponding frequency and time of the transmission channel 360. The frequency and time of the transmission channel 360 can define the initial time and initial frequency of the signal. Furthermore, the transmission channel 360 can receive time synchronization signals from a global navigation satellite system (e.g., GNSS 363), a term used to describe satellite constellations that provide positioning, navigation, and timing services on a global or regional basis, such as the Global Positioning System.

[0130] Figure 9An exemplary embodiment of a method for suppressing time-frequency-code interference for a sensor according to embodiments of the present disclosure is shown. Method 900 begins at step 905, wherein a first chirp signal is generated by a first sensor in a first channel and transmitted from a vehicle, wherein the first channel includes a time channel, a frequency channel, and a code dimension. Figure 3 The processing flow 300 discussed herein may include a channel limitation component 310, a required channel calculation component 315, a codeword library 320, a channel hopping component 340, a listening mode component 345, an interference noise estimation component 350, a codeword selection component 355, and a time source GNSS 363 (Global Navigation Satellite System) component. The channel limitation component 310 may include time components, frequency components, and semi-orthogonal code dimension channel components. The actual determination of the time-frequency-code channel can be achieved by the required channel calculation component 315, where different types of waveforms may require multiple time channels and frequency channels, such as... Figure 6 As illustrated in the diagram. Furthermore, the codeword library 320 component can contain available codewords, where the orthogonality of the codewords can also be affected by the number of codewords used. And, in a scenario where a specific time-frequency-code channel becomes noisy or occupied, the channel switching 340 component can use noise data estimated by noise estimation 335 to determine a new time-frequency-code channel.

[0131] Step 910 includes generating and transmitting a second chirped signal by a second sensor in a second channel, wherein the second channel includes a time channel, a frequency channel, and a code dimension. In one embodiment, different sensors are associated with each channel, thereby suppressing interference. However, the sensors may include multiple components to achieve the same effect, i.e., multiple signal waveforms are generated in different frequency-time-code channels where the signals can not interfere with each other.

[0132] In step 915, a first reflected signal from one or more objects may be received by a first sensor from the first chirp signal. For example... Figure 3 As illustrated, the generated signal can be transmitted as a waveform signal 372 by the transmitting component 365 to the transmitting antenna component 370, for example. The waveform signal 372 can be reflected by one or more objects such as the target vehicle 323, thereby generating a first reflected signal, for example, the reflected signal 324.

[0133] In step 920, a second sensor may receive a second reflected signal from one or more objects from the first chirp signal. For example... Figure 3As illustrated, the generated signal can be transmitted as a waveform signal 372 by the transmitting component 365 to the transmitting antenna component 370, for example. The waveform signal 372 can be reflected by one or more objects such as the target vehicle 323, thereby generating a first reflected signal, for example, the reflected signal 324.

[0134] In step 925, the difference between the first chirped signal and the second chirped signal is further defined. For example, the second channel may include one or more different time channels, different frequency channels, or different code dimensions relative to the first channel. As discussed with respect to component 310, the definition of the channel may include time components, frequency components, and semi-orthogonal code dimension channel components. Processing flow 300 may include a time-frequency coding scheme that can be modified to incorporate coding by transmitting the encoded signal. For example, after a time-frequency channel hopping initiated by a high noise level or interference detection, the new time-frequency channel undergoes listening to find an existing codeword. The codeword can then be selected for transmission by the sensor based on the code channel with the lowest noise.

[0135] Furthermore, the total number of possible channels can be limited to the number of time channels multiplied by the number of frequency channels. Additionally, as for each time-frequency channel, an additional N can be transmitted. c Codewords. Therefore, the total number of channels can be limited to the number of time channels multiplied by the number of frequency channels multiplied by the number of codewords.

[0136] In step 930, the selection of code dimensions can be limited, wherein the code dimensions of the first channel and the second channel are determined from a set of code dimensions based on the lowest interference noise estimation. As discussed, the noise estimation component 335 can estimate the noise level for each distance of the channel using two methods based on the following formula after distance processing:

[0137]

[0138] Noise2 = argmax k,n,h |RTC[k,n,h]|-|RTC[k,n-1,h]|

[0139] RDC[k,l,h] can be a cube of signal data after the range FFT and Doppler FFT but before digital beamforming, and it has a range dimension k, a Doppler dimension l, and a channel dimension h.

[0140] H, L, and K can represent the number of samples in the range dimension, Doppler dimension, and channel dimension, respectively. Noise2 can take advantage of the fact that interference sources are not perfectly time-synchronized and may not appear in every chirp. Furthermore, the diff function can search for and detect high-energy differences caused by interference variations. RTC[k,n,h] can represent the cube of signal data after the range FFT but before the Doppler FFT.

[0141] Method 900 can then be completed.

[0142] The specification section and the summary section may set forth one or more embodiments of this disclosure as conceived by the inventors, and are therefore not intended to limit the disclosure and the appended claims.

[0143] Embodiments of this disclosure have been described above using functional building blocks that illustrate the implementation of specified functions and their relationships. For ease of description, the boundaries of these functional blocks are arbitrarily defined herein. Alternative boundaries can be defined as long as the specified functions and their relationships can be properly performed.

[0144] The foregoing description of the specific embodiments so fully reveals the general nature of this disclosure that others can readily modify and / or adapt these specific embodiments for various applications by applying knowledge of the art without departing from the general concept of this disclosure, without excessive experimentation. Therefore, based on the teachings and guidance provided herein, such modifications and adjustments are intended to be within the meaning and scope of equivalents of the disclosed embodiments. It should be understood that the wording or terminology herein is for descriptive purposes and not for limitation, and that the terminology or terminology of this specification should be interpreted by those skilled in the art based on the teachings and guidance.

[0145] The breadth and scope of this disclosure should not be limited by the exemplary embodiments described above.

[0146] Exemplary embodiments of this disclosure have been presented. This disclosure is not limited to these examples. These examples are provided herein for illustrative purposes and not for limiting purposes. Based on the teachings contained herein, alternatives (including equivalents, extensions, variations, deviations, etc.) will be apparent to those skilled in the art. Such alternatives fall within the scope and spirit of this disclosure.

Claims

1. A system for time-frequency coding using Code Division Multiple Access (CDMA) for interference suppression of vehicle sensors, comprising: A first sensor in the vehicle is configured to: generate and transmit a first chirped signal in a first channel, and receive a first reflected signal from one or more objects from the first chirped signal, wherein the first channel includes a time channel, a frequency channel, and a code dimension; and A second sensor is configured to: generate and transmit a second chirped signal in a second channel, and receive a second reflected signal from one or more objects from the second chirped signal, wherein the second channel includes a time channel, a frequency channel, and a code dimension; The second channel includes one or more different time channels, different frequency channels, or different code dimensions relative to the first channel, and The code dimension of the first channel and the code dimension of the second channel are determined from a set of code dimensions based on the lowest interference noise estimation.

2. The system according to claim 1, wherein, The second sensor is configured to enter a listening mode to determine the interference noise estimate for each code dimension in the set of code dimensions.

3. The system according to claim 1, wherein, The first sensor and the second sensor are time-synchronized.

4. The system according to claim 1, wherein, The first code dimension is semi-orthogonal to the second code dimension in this set of code dimensions.

5. The system according to claim 1, further comprising processing logic for determining the noise level of the first reflected signal, wherein, The noise level is stored in a memory that includes a time decay mechanism.

6. The system according to claim 5, wherein, When the noise level is greater than a threshold, the first sensor is configured to generate a subsequent chirped signal in the third channel.

7. The system according to claim 1, wherein, When the noise level is greater than the threshold level, the current channel is classified as occupied.

8. The system according to claim 1, wherein, The first sensor and the second sensor are configured not to transmit on occupied frequency channels.

9. A method for time-frequency coding using Code Division Multiple Access (CDMA) for interference suppression of vehicle sensors, comprising: A first chirp signal is generated by a first sensor in a first channel and transmitted from the vehicle, wherein the first channel includes a time channel, a frequency channel, and a code dimension; A second chirp signal is generated and transmitted by a second sensor in a second channel, wherein the second channel includes a time channel, a frequency channel, and a code dimension; The first sensor receives a first reflected signal from one or more objects from the first chirp signal; and The second sensor receives a second reflected signal from one or more objects from the second chirp signal; The second channel includes one or more different time channels, different frequency channels, or different code dimensions relative to the first channel, and The code dimension of the first channel and the code dimension of the second channel are determined from a set of code dimensions based on the lowest interference noise estimation.

10. A method for time-frequency coding using Code Division Multiple Access (CDMA) for interference suppression of vehicle sensors, comprising: A first chirp signal is generated by a first sensor in a first channel and transmitted from the vehicle, wherein the first channel includes a time channel, a frequency channel, and a code dimension; A second chirp signal is generated and transmitted by a second sensor in a second channel, wherein the second channel includes a time channel, a frequency channel, and a code dimension; The first sensor receives a first reflected signal from one or more objects from the first chirp signal; The second sensor receives a second reflected signal from one or more objects from the second chirp signal; The second sensor monitors and determines the interference noise estimate for each code dimension in the set of code dimensions; The noise level of the first reflected signal is determined by processing logic, wherein the noise level is stored in a memory including a time decay mechanism; and A first noise estimation is performed based on the range fast Fourier transform (FFT) and the Doppler FFT before digital beamforming is applied to the first reflected signal; and a second noise estimation is performed based on the range fast Fourier transform (FFT) before the Doppler FFT is applied to the first reflected signal. The second channel includes one or more different time channels, different frequency channels, or different code dimensions relative to the first channel, and The code dimension of the first channel and the code dimension of the second channel are determined from a set of code dimensions based on the lowest interference noise estimation.

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