92GHz MIMO roadside radar radio frequency system based on frequency conversion assembly

Abstract

The invention relates to a 92GHz MIMO roadside radar radio frequency system based on a frequency conversion assembly, and the radar radio frequency system comprises a baseband processing layer which comprises at least two cascaded millimeter wave system-level SoC chips; the frequency conversion layer is a frequency conversion module FCM, and the FCM comprises a local oscillator synthesis unit, an upper mixer group and a lower mixer group; the local oscillation synthesis unit is used for generating a 13GHz local oscillation signal; the input end of the upper mixer group is connected with the output end of the baseband processing layer, the local oscillation end of the upper mixer group is connected with the local oscillation synthesis unit, the output end of the lower mixer group is connected with the input end of the baseband processing layer, and the local oscillation end of the lower mixer group is connected with the local oscillation synthesis unit; and the down-conversion layer is used for down-converting 92-94 GHz echo signals received by the antenna array to 79-81 GHz and then outputting the echo signals to the baseband processing layer. According to the invention, 92-94 GHz frequency conversion can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radio frequency technology, in particular to a 92GHz MIMO roadside radar radio frequency system based on a frequency conversion component. BACKGROUND

[0002] Millimeter wave radar technology has become a core sensor in intelligent transportation, autonomous driving and industrial perception due to its all-weather, high-precision and non-contact measurement advantages. In roadside radar applications, millimeter wave radar systems undertake key tasks such as traffic flow monitoring, target tracking, event detection and safety warning, which are of great significance to improving road safety and efficiency. In order to pursue higher perception accuracy and resolution, the industry is gradually expanding to higher frequency bands. The 92GHz frequency band has great application potential and is widely concerned by the industry because it can achieve higher angular resolution and more compact antenna size due to its shorter wavelength.

[0003] Currently, mainstream millimeter wave radar systems generally use high-integration system-on-chip architecture, but their working frequency bands are mostly concentrated in 77-81GHz.

[0004] However, the existing 77-81GHz high-integration SoC-based architecture, due to its inherent technical principle limitations, is difficult to balance high performance, low cost and high reliability when expanding to the 92GHz high-frequency band to cope with complex roadside applications. Therefore, there is an urgent need for a new technical solution. SUMMARY

[0005] Therefore, it is necessary to provide a 92GHz MIMO roadside radar radio frequency system based on a frequency conversion component based on a frequency conversion component for realizing frequency conversion.

[0006] The present application provides a 92GHz MIMO roadside radar radio frequency system based on a frequency conversion component, which comprises a baseband processing layer, a frequency conversion layer and an antenna array; wherein: The baseband processing layer comprises at least two cascaded millimeter wave system-on-chip chips, which are used to generate 79-81GHz transmit signals and process 79-81GHz receive signals; The frequency conversion layer is a frequency conversion component FCM, and the FCM comprises a local oscillator synthesis unit, an upper mixer group and a lower mixer group; The local oscillator synthesis unit is used to generate a 13GHz local oscillator signal; The input end of the upper mixer group is connected to the output end of the baseband processing layer, and the local oscillator end of the upper mixer group is connected to the local oscillator synthesis unit, which is used to up-convert the 79-81GHz transmit signal to 92-94GHz and then output to the antenna array; The output end of the down-mixer group is connected to the input end of the baseband processing layer, and the local oscillator end of the down-mixer group is connected to the local oscillator synthesis unit, for down-converting the echo signal received by the antenna array at 92-94 GHz to 79-81 GHz and then outputting to the baseband processing layer.

[0007] In one of the embodiments, the millimeter wave system level SoC chip is further configured to perform a frequency parameter self-adaptive adjustment algorithm for finding a target working point with minimum interference by: measuring an initial interference power value at a current working point, the current working point being defined by a set of values of system working parameters; adjusting the value of each system working parameter in the current working point respectively, and measuring a response interference power value after each adjustment; determining a gradient vector of the interference power with respect to each system working parameter according to the difference between the response interference power value after each adjustment and the initial interference power value; determining a candidate working point according to the gradient vector; judging whether the candidate working point meets preset physical and protocol constraints; if yes, generating a control instruction to distribute the values of each system working parameter in the candidate working point to corresponding system components for execution, and taking the candidate working point as the target working point; if no, modifying the candidate working point to a nearest point meeting the physical and protocol constraints, and generating a control instruction to adjust the values of each system working parameter to the nearest point and taking the nearest point as the target working point.

[0008] In one of the embodiments, the system working parameters include one or more of the following: the output frequency of the local oscillator synthesis unit, the transmit power of the millimeter wave system level SoC chip, the receiver gain, and the frequency modulation slope of the linear frequency modulation signal.

[0009] In one of the embodiments, the gradient vector of the interference power with respect to each system working parameter is determined according to the difference between the response interference power value after each adjustment and the initial interference power value, including: for each system working parameter to be optimized in the current working point, the following operations are performed: keeping other system working parameters in the current working point unchanged, increasing the value of the system working parameter to be optimized by a positive perturbation amount, and measuring a first response interference power value; dividing the difference between the first response interference power value and the initial interference power value by the positive perturbation amount to calculate an estimated value of the change rate of the interference power with respect to the system working parameter to be optimized; Correspondingly, after all the system operating parameters to be optimized in the current operating point are traversed, the obtained change rate estimates are combined to obtain a gradient vector of the interference power with respect to each system operating parameter.

[0010] In one of the embodiments, the difference between the first response interference power value and the initial interference power value is divided by the positive perturbation amount to calculate an estimate of the change rate of the interference power with respect to the system operating parameter to be optimized, including: The value of the system operating parameter to be optimized is increased by the negative perturbation amount while keeping other system operating parameters in the current operating point unchanged, and a second response interference power value is measured; The difference between the first response interference power value and the second response interference power value is divided by twice the perturbation amount to calculate an estimate of the change rate of the interference power with respect to the system operating parameter to be optimized.

[0011] In one of the embodiments, the preset physical and protocol constraints include that the operating frequency band of the radio frequency signal transformed by the frequency conversion layer is located in the range of 92-94 GHz, and the transmission power of the millimeter wave system level SoC chip does not exceed the legal limit.

[0012] In one of the embodiments, the candidate operating point is determined according to the gradient vector, including: The coordinate value of the current operating point is subtracted by the product of the gradient vector and a preset learning rate factor to obtain a calculation result, and the calculation result is taken as the candidate operating point.

[0013] In one of the embodiments, the trigger condition for triggering the loop execution of the frequency parameter adaptive adjustment algorithm is that the length of the gradient vector is less than a preset threshold, or the change amount of the initial interference power value in continuous preset number of iterations is less than a preset tolerance.

[0014] In one of the embodiments, the radar radio frequency system is configured to execute a self-calibration mode, in which the baseband processing layer can control the local oscillator synthesis unit and the up-mixer group to generate a calibration signal with a known power, and the calibration signal is sent back to the baseband processing layer via the down-mixer group for link gain measurement.

[0015] In one of the embodiments, the frequency conversion component FCM further includes a temperature sensor integrated inside.

[0016] The 92GHz MIMO roadside radar radio frequency system based on the frequency conversion component, by introducing the frequency conversion layer FCM, successfully up-converts the baseband signal of the mature 79-81GHz millimeter wave system level SoC chip to 92-94GHz, thereby combining the cost and reliability advantages of low-frequency chips with the beam precision and resolution advantages of high-frequency chips, avoiding the technical challenges and high cost of directly developing a 92GHz high-frequency SoC, and providing a solution for realizing high-performance and high-reliability roadside radar sensing. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the description of the embodiments of the present application or the related art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other related drawings can also be obtained without creative labor.

[0018] Figure 1 The system architecture diagram of a 92GHz MIMO roadside radar radio frequency system based on a frequency conversion component in an embodiment; Figure 2 The communication link schematic diagram of a 92GHz MIMO roadside radar radio frequency system based on a frequency conversion component in an embodiment; Figure 3 The flowchart of the frequency parameter self-adaptive adjustment algorithm in an embodiment; Explanation of reference signs: 10, baseband processing layer; 20, frequency conversion layer; 30, antenna array. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0020] The 92GHz Multiple-Input Multiple-Output (MIMO) roadside radar radio frequency system is an advanced sensor system deployed at the edge of the road. Its core feature is to use the millimeter wave frequency band near 92GHz (such as 92-94GHz) for detection, and to use MIMO technology. The system transmits and receives signals simultaneously through multiple antennas, and uses signal processing to synthesize a virtual aperture, thereby improving the detection distance, speed measurement and angle resolution accuracy of vehicles, pedestrians and other targets in the road scene without significantly increasing the hardware volume.

[0021] In one exemplary embodiment, as shown in Figure 1 A 92GHz MIMO roadside radar RF system based on a frequency conversion component is provided, which includes a baseband processing layer 10, a frequency conversion layer 20, and an antenna array 30. The system uses the frequency conversion layer 20 as a frequency band adaptation bridge to up-convert the 79-81GHz signal generated by the baseband processing layer to a 92-94GHz transmission and down-convert the 92-94GHz echo signal received by the antenna array to 79-81GHz for baseband processing, achieving the core goal of migrating the working frequency band while keeping the baseband architecture unchanged, and taking into account the low-cost advantage of mature SoC chips and the high-resolution performance of the 92GHz frequency band. Figure 1 That is, the layered structure diagram of the 92GHz MIMO roadside radar RF system based on a frequency conversion component: The lowest layer is the baseband processing layer 10, which is connected to the external control / power supply module through connectors 1 and 2, integrates core circuits such as millimeter wave system-level SoC chips, and provides signal processing and control functions for the upper layer. The middle layer is the frequency conversion layer 20, which is the core functional layer for converting the 79-81GHz and 92-94GHz frequency bands, and is tightly connected to the baseband processing layer 10 and the antenna array 30 through internal RF traces / interfaces. The top layer is the antenna array 30, which includes transmit antennas (TX) and receive antennas (RX), TX for radiating 92-94GHz transmission signals, and RX for receiving 92-94GHz echo signals reflected by the target.

[0022] The above components will be introduced one by one as follows: Among them, the baseband processing layer 10 includes at least two cascaded millimeter wave system-level (System on a Chip, SoC) chips, which are used to generate 79-81GHz transmission signals and process 79-81GHz reception signals.

[0023] Optionally, the baseband processing layer 10 includes at least two cascaded millimeter wave system-level SoC chips, and a single chip can integrate 3 transmit (Tx) / 4 receive (Rx) channels. Through a master-slave cascading mode (for example, the master chip outputs a 40MHz reference clock through the OSC_CLKOUT port to the slave chip to ensure synchronization between multiple chips), it can be expanded to a 6Tx / 8Rx (6T8R) MIMO channel configuration, and the double-chip ADC sampling window deviation is strictly controlled within 5-10ns through a frame reference counter, ensuring the phase consistency of multiple channel signals.

[0024] The core function is implemented as follows: generating 79-81GHz transmission signal: the millimeter wave system level SoC chip generates a frequency modulated continuous wave (FMCW) signal through the built-in fractional N type PLL Chirp engine, and outputs the signal to the frequency conversion layer 20 through the internal power amplifier link. The 79-81GHz frequency band is the native working frequency band of the millimeter wave system level SoC chip, and the mature chip driver and signal generation logic can be directly reused without modifying the chip hardware architecture.

[0025] Processing 79-81GHz receiving signal: receiving the 79-81GHz signal returned by the receiving frequency conversion layer 20, pre-amplifying the signal through the built-in low noise amplifier (LNA) of the chip, digitizing the analog signal through the 45Msps sampling rate analog-digital converter (ADC), and finally executing the target detection, distance / speed / angle calculation algorithm by the built-in digital signal processor (DSP), completing the signal analysis and target information extraction.

[0026] Among them, the frequency conversion layer 20 is a frequency conversion component (Frequency Conversion Module, FCM), and the FCM includes a local oscillator synthesis unit, an upper mixer group and a lower mixer group.

[0027] Among them, the local oscillator synthesis unit is used to generate a 13GHz local oscillator signal.

[0028] Optionally, the local oscillator synthesis unit is designed based on an integrated PLL chip and an external balun. The core function is to generate a stable and low-noise 13GHz local oscillator signal. The frequency value is based on the frequency conversion logic (79-81GHz+13GHz=92-94GHz, 92-94GHz-13GHz=79-81GHz) that the transmission frequency band=baseband signal frequency+local oscillator frequency, and the receiving baseband signal frequency=echo frequency band-local oscillator frequency, to ensure that there is no frequency offset in the frequency conversion process. The phase noise of the 13GHz local oscillator signal is better than -110dBc / Hz at 100kHz offset, and the output power is stable at 3.5dBm; when the local oscillator signal is distributed to 8 mixing channels through a power division network, a λ / 4 impedance transformer and an isolation resistor are used to optimize the crosstalk between channels, and the crosstalk suppression capability is ≥25dB, to ensure the frequency stability during long time work.

[0029] As shown in Figure 2 , it is a signal processing flowchart of the frequency conversion layer 20, which includes: The 79-81GHz transmit signal output by the baseband processing layer (79-81GHz input arrow in the figure) is input to the TX_IN1-TX_IN4 ports of the up-mixer group; the 13GHz local oscillator signal generated by the local oscillator synthesis unit is synchronously input to the local oscillator port of the up-mixer group; the up-mixer group performs frequency conversion operation to combine the 79-81GHz signal and the 13GHz local oscillator signal into a 92-94GHz signal , and outputs the 92-94GHz signal from the TX_OUT1-TX_OUT4 ports to the antenna array 30, to complete the frequency band upshifting of the transmit signal.

[0030] The 79-81GHz transmit signal output by the baseband processing layer (79-81GHz input arrow in the figure) is input to the TX_IN1-TX_IN4 ports of the up-mixer group; the 13GHz local oscillator signal generated by the local oscillator synthesis unit is synchronously input to the local oscillator port of the up-mixer group; the up-mixer group performs frequency conversion operation to combine the 79-81GHz signal and the 13GHz local oscillator signal into a 92-94GHz signal

[0031] The input end of the up-mixer group is connected to the output end of the baseband processing layer 10, and the local oscillator end of the up-mixer group is connected to the local oscillator synthesis unit, for up-converting the 79-81GHz transmit signal to 92-94GHz and then outputting the 92-94GHz signal to the antenna array 30.

[0032] Optionally, the up-mixer group adopts a 4-channel integrated design, and corresponds to the 4 transmit channels of the baseband processing layer 10 in one-to-one manner, and the hardware connection relationship strictly follows the modified claim 1: the input end is connected to the output end of the baseband processing layer 10, and the local oscillator end is connected to the local oscillator synthesis unit. Specifically, through the upper sideband mixing technology, the 79-81GHz transmit signal output by the baseband processing layer and the 13GHz local oscillator signal provided by the local oscillator synthesis unit are nonlinearly combined in the mixer to extract the upper sideband component (i.e. 92-94GHz) of the baseband signal frequency plus the local oscillator frequency, and after filtering out the spurs by the internal filter circuit, the 92-94GHz signal is transmitted from the output end to the antenna array 30. The frequency conversion loss of the mixer is controlled within 8-10dB, to ensure that the output signal power meets the radar detection distance requirement (typical output power≥-5dBm).

[0033] The input end of the up-mixer group is connected to the output end of the baseband processing layer 10, and the local oscillator end of the up-mixer group is connected to the local oscillator synthesis unit, for up-converting the 79-81GHz transmit signal to 92-94GHz and then outputting the 92-94GHz signal to the antenna array 30.

[0034] Optionally, the down-mixer group is also designed with 4-channel integration, corresponding to the 4 receiving channels of the baseband processing layer 10, and the connection relationship is: the output end is connected to the input end of the baseband processing layer 10, and the local oscillator end is connected to the local oscillator synthesis unit. Specifically: a mirror suppression mixing architecture is adopted, and the 92-94GHz echo signal received by the antenna array 30 is mixed with the 13GHz local oscillator signal to extract the lower sideband component of the echo signal frequency-local oscillator frequency (i.e. 79-81GHz); at the same time, the built-in 90° phase shift network eliminates the mirror interference of the 79-81GHz intermediate frequency signal (the mirror suppression ratio is ≥30dB), and the low noise amplifier (LNA) is integrated in front of the mixer to control the noise figure of the receiving link at 3-4dB, enhancing the receiving ability of the weak echo signal of the long distance and small target.

[0035] Further, the antenna array 30, as the air interface for signal transmission and reception, is connected to the output end of the up-mixer group and the input end of the down-mixer group of the FCM through a standard WR10 waveguide port-WR10 waveguide is a low-loss transmission structure for the 92-94GHz frequency band, and the transmission loss in this frequency band is ≤0.5dB / m, which can effectively reduce the attenuation of high-frequency signals in the transmission process and ensure the radar detection distance (typical detection distance ≥200m) and signal integrity. The working process of the antenna array 30: receiving the 92-94GHz transmission signal output by the up-mixer group, and radiating it to the roadside detection area in the form of electromagnetic waves; at the same time, capturing the 92-94GHz echo signal reflected by the target, and transmitting it to the input end of the down-mixer group through the WR10 waveguide to complete the signal transmission-reception closed loop.

[0036] In one exemplary embodiment, as shown in Figure 3 The millimeter wave system level SoC chip is also configured to perform a frequency parameter adaptive adjustment algorithm for finding a target working point with minimum interference in the following manner, and the specific implementation process of the algorithm is as follows: S301, measure the initial interference power value at the current working point.

[0037] Wherein, the current working point is defined by the values of a set of system working parameters.

[0038] Optionally, the system working parameters include one or more of the following: the output frequency of the local oscillator synthesis unit, the transmit power of the millimeter wave system level SoC chip, the receiver gain of the millimeter wave system level SoC chip, and the frequency modulation slope of the linear frequency modulation signal, which is represented by a vector as follows:

[0039] Wherein, is the initial local oscillator frequency, is the initial transmit power, is the initial receiver gain, This represents the initial frequency modulation slope.

[0040] Furthermore, the initial interference power value is measured: the spectrum analysis module built into the millimeter-wave system-on-a-chip (SoC) is used to collect the current operating point data in real time. Interference signals (including environmental clutter, interference from other radio equipment, etc.) in the downlink are measured, and the initial interference power value is recorded as follows. This serves as a benchmark for subsequent parameter adjustments.

[0041] S302. Adjust the value of each system operating parameter at the current operating point and measure the response interference power value after each adjustment.

[0042] Optionally, based on the difference between the adjusted response interference power value and the initial interference power value, the gradient vector of the interference power changing with each system operating parameter is determined, including: for each operating parameter of the system to be optimized at the current operating point, the following operations are performed: keeping other system operating parameters at the current operating point unchanged, adding a positive disturbance to the value of the operating parameter of the system to be optimized, and measuring the first response interference power value; dividing the difference between the first response interference power value and the initial interference power value by the positive disturbance to calculate the estimated rate of change of the interference power with respect to the operating parameter of the system to be optimized.

[0043] Specifically, the difference between the first response interference power value and the initial interference power value is divided by a positive disturbance amount to calculate the estimated rate of change of the interference power with respect to the operating parameters of the system to be optimized. This includes: keeping other system operating parameters at the current operating point unchanged, adding a negative disturbance amount to the value of the operating parameters of the system to be optimized, and measuring the second response interference power value; the difference between the first response interference power value and the second response interference power value is divided by twice the disturbance amount to calculate the estimated rate of change of the interference power with respect to the operating parameters of the system to be optimized.

[0044] First, adjust the positive disturbance amount and measure the first response interference power value: add a positive disturbance amount (e.g., positive disturbance amount of the local oscillator frequency) to the value of the operating parameter of the system to be optimized. positive perturbation of transmit power To obtain new parameter values , (This is the positive disturbance value); Under this parameter configuration, the interference power value is measured and recorded as the first response interference power value. Secondly, the negative disturbance adjustment and the measurement of the second response disturbance power value: keeping other system operating parameters unchanged, the value of the same operating parameter of the system to be optimized is increased by a negative disturbance (i.e., ), This is the positive disturbance amount; under this parameter configuration, the interference power value is measured and recorded as the second response interference power value; where the perturbation amount should be small and within the safe range of parameters, for example, the perturbation amount of the local oscillator frequency should not exceed ±5MHz (to avoid the frequency band exceeding 92-94GHz after frequency conversion), and the perturbation amount of the transmit power should not exceed ±1dBm (to avoid approaching the legal limit).

[0045] S303, according to the difference between the adjusted response interference power value and the initial interference power value, determine the gradient vector of the interference power with respect to each system operating parameter.

[0046] Optionally, for each system operating parameter to be optimized, the difference between the first response interference power value and the second response interference power value is used to calculate the change rate estimate of the interference power with respect to the parameter, and the formula is:

[0047] The formula offsets the error caused by the nonlinear characteristics of the system through the bidirectional perturbation amount, so that the change rate estimate is closer to the true value (compared to the single-directional perturbation amount, the error can be reduced by more than 30%).

[0048] S304, according to the gradient vector, determine the candidate operating point.

[0049] Optionally, correspondingly, after all the system operating parameters to be optimized in the current operating point are traversed, the obtained change rate estimates are combined to obtain the gradient vector of the interference power with respect to each system operating parameter, denoted as:

[0050] where represents the gradient of the interference power P with respect to the system operating parameter vector. It is a vector, each component of which represents the change rate of the interference power in the corresponding parameter direction, and the direction of the gradient indicates the direction in which the interference power grows fastest. Therefore, in the optimization algorithm, the parameters are adjusted in the opposite direction of the gradient P) to make the interference power decrease. The unit of each component is [interference power unit] / [unit of the corresponding parameter], for example, dBm / MHz.

[0051] where is the first response interference power value. This is the interference power value measured when only the local oscillator frequency is increased by a positive perturbation amount , while all other parameters remain unchanged, and the unit is dBm (decibel milliwatt) or other power units; is the second response interference power value. This is the interference power value measured when only the local oscillator frequency is increased by a negative perturbation amount - The measured interference power value, in units of dBm (decibel-milliwatt) or other power units, when all other parameters remain unchanged.

[0052] wherein, is the measured interference power value when only the transmit power is increased by a positive perturbation amount . is the measured interference power value when only the transmit power is increased by a negative perturbation amount .

[0053] wherein, is the measured interference power value when only the receiver gain is increased by a positive perturbation amount . is the measured interference power value when only the receiver gain is increased by a negative perturbation amount .

[0054] wherein, is the measured interference power value when only the frequency modulation slope is increased by a positive perturbation amount . is the measured interference power value when only the frequency modulation slope is increased by a negative perturbation amount .

[0055] Optionally, the candidate working point is determined according to the gradient vector, including: subtracting the product of the gradient vector and a preset learning rate factor from the coordinate value of the current working point to obtain a calculation result, and taking the calculation result as the candidate working point.

[0056] For example, the gradient descent method is used to adjust the parameters in the direction of the fastest interference power decrease, and the calculation formula is:

[0057] wherein, is the calculated candidate working point; is a preset learning rate factor (typically 0.1-0.3), used to control the parameter adjustment amplitude. A too large learning rate will cause parameter overshoot (such as transmit power exceeding the legal limit), and a too small learning rate will cause slow algorithm convergence (more than 50% increase in iteration times). In actual applications, the learning rate can be dynamically adjusted according to the interference variation amplitude (take a small when the interference variation is large, and take a large when the interference is stable).

[0058] S305. Determine whether the candidate working point meets the preset physical and protocol constraints.

[0059] The preset physical and protocol constraints include: the operating frequency band of the radio frequency signal after conversion by the frequency conversion layer 20 is in the range of 92-94GHz, and the transmit power of the millimeter-wave system-on-a-chip does not exceed the legal limit.

[0060] Optionally, calculate candidate operating points. Corresponding radio frequency transmission band ( , (Baseband signal frequency), determine whether it meets the requirements. If the value exceeds this range, it indicates that the frequency band after frequency conversion does not meet the system design requirements and needs to be corrected.

[0061] The transmit power constraint is: to determine the transmit power among the candidate operating points. Does it meet the requirements? <<Statutory limits (e.g., the statutory limit for the transmit power of a 92GHz roadside radar is ≤23dBm); if the limit is exceeded, the transmit power must be forcibly corrected to the statutory limit.

[0062] Furthermore, the frequency conversion component FCM also includes an integrated temperature sensor.

[0063] Optionally, in conjunction with the temperature sensor integrated into the FCM, it is necessary to supplement the constraint judgment after temperature compensation: read the real-time reading T of the temperature sensor inside the FCM, and based on the pre-stored thermal drift model (such as... , For temperature coefficient, Using the reference temperature, calculate the temperature drift of each system's operating parameters; use the temperature drift to determine candidate operating points. Compensation is performed to obtain the candidate operating point after temperature compensation. Reassess Whether it complies with the above physical and protocol constraints, ensuring that temperature changes (such as the temperature of roadside equipment rising to 60°C in summer) do not cause parameter deviations.

[0064] S306. If the conditions are met, control instructions are generated to distribute the values ​​of each system operating parameter contained in the candidate operating point to the corresponding system components for execution, and the candidate operating point is used as the target operating point.

[0065] Optionally, if the candidate operating point meets the constraints: generate control instructions to... The system operating parameter values ​​contained therein are distributed to the corresponding system components (local oscillator synthesis unit, millimeter-wave system-on-a-chip transmit / receive link, signal modulation module) for execution. This is the target working point.

[0066] S307. If not, the candidate operating point is corrected to the nearest point that meets the physical and protocol constraints, and control instructions are generated to adjust the values ​​of each system operating parameter to the nearest point, and the nearest point is used as the target operating point.

[0067] Optionally, if the candidate operating point does not meet the constraints: use the projection method to... Corrected to the nearest point that meets the constraints, for example: if the RF band exceeds 94GHz, the local oscillator frequency will be adjusted. Revised to If the transmission power exceeds the limit, The value is corrected to the legal limit; after correction, a control command is generated to adjust the system parameters to the nearest point, which is the target operating point.

[0068] In one exemplary embodiment, the radar radio frequency system is configured to perform a self-calibration mode, in which the baseband processing layer 10 can control the local oscillator synthesis unit and the up mixer group to generate a calibration signal with known power, and send it back to the baseband processing layer 10 via the down mixer group for link gain measurement.

[0069] Understandably, this mode is independent of the frequency parameter adaptive adjustment algorithm and can be triggered on demand (such as when the system is powered on or periodically every 24 hours). Its core purpose is to correct the gain drift of the receiving link and ensure the accuracy of signal measurement.

[0070] The specific implementation process is as follows: First, calibration signal generation and injection: The baseband processing layer 10 sends control commands to the local oscillator synthesis unit and the up mixer group to control the local oscillator synthesis unit to generate a 13GHz calibration local oscillator signal. The up mixer group mixes this signal with a fixed frequency (e.g., 80GHz) signal generated by the baseband to generate a calibration signal with known power (typical power of -10dBm, power accuracy ±0.2dBm). Through an internal coupling link, the calibration signal is injected into the input of the down mixer group (analog echo signal path).

[0071] Secondly, calibration signal feedback and gain measurement: The down-mixer group down-converts the calibration signal to 79-81GHz (consistent with the normal echo signal frequency band) and sends it back to the receiver of the baseband processing layer 10; the baseband processing layer measures the power of the feedback calibration signal using a built-in power meter, denoted as . .

[0072] Then, the link gain is calculated based on the injected calibration signal power. With measurement calibration signal power Calculate the net gain of the current receiving link. ;Will The gain drift is obtained by comparing it with the rated gain of the receiving link (typically 20dB). , which can be used for parameter compensation (e.g., correcting receiver gain ) of subsequent frequency parameter adaptive adjustment algorithm.

[0073] It can be understood that, through the self-calibration mode, the gain error of the receiving link can be controlled within ±0.5 dB, avoiding the influence of gain drift caused by long-term work (e.g., component aging) on the interference power measurement accuracy.

[0074] Optionally, the trigger condition for triggering the frequency parameter adaptive adjustment algorithm to execute in a loop is that the length of the gradient vector is less than a preset threshold, or the change amount of the initial interference power value in continuous preset number of iterations is less than a preset tolerance.

[0075] In combination with the above example, the length of the gradient vector is less than a preset threshold: ( , which is typically 0.1 dBm / parameter unit, indicating that the influence of parameter adjustment on the interference power is very small, and the system tends to be stable; the change amount of the initial interference power value in continuous preset number of iterations is less than a preset tolerance: in continuous N times (N is a preset number, typically 5-8 times) of iterations, , , which is typically 0.5 dBm, indicating that the interference power has stabilized at a low level, and there is no need to continue adjustment. When any of the above conditions is met, the algorithm stops looping, and the system maintains the current target operating point; if not, return to S301 to re-execute iteration.

[0076] The technical features of the above embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0077] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be noted that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A 92GHz MIMO roadside radar radio frequency system based on a frequency conversion component, characterized in that, The radar radio frequency system includes a baseband processing layer (10), a frequency conversion layer (20), and an antenna array (30); wherein: The baseband processing layer (10) includes at least two cascaded millimeter-wave system-on-a-chip (SoC) chips for generating 79-81 GHz transmit signals and processing 79-81 GHz receive signals. The frequency conversion layer (20) is a frequency conversion component FCM, which includes a local oscillator synthesis unit, an up mixer group and a down mixer group; The local oscillator synthesis unit is used to generate a 13GHz local oscillator signal; The input end of the upmixer group is connected to the output end of the baseband processing layer (10), and the local oscillator end of the upmixer group is connected to the local oscillator synthesis unit, which is used to upconvert the 79-81GHz transmission signal to 92-94GHz and then output it to the antenna array (30). The output of the downmixer group is connected to the input of the baseband processing layer (10), and the local oscillator of the downmixer group is connected to the local oscillator synthesis unit, which is used to downconvert the 92-94GHz echo signal received by the antenna array (30) to 79-81GHz and then output it to the baseband processing layer (10).

2. The system according to claim 1, characterized in that, The millimeter-wave system-on-a-chip (SoC) is also configured to execute an adaptive frequency parameter adjustment algorithm to find the target operating point with minimal interference in the following ways: Measure the initial interference power value at the current operating point, which is defined by a set of system operating parameters; Adjust the value of each system operating parameter at the current operating point, and measure the response interference power value after each adjustment; Based on the difference between the adjusted response interference power value and the initial interference power value, the gradient vector of the interference power as a function of each system operating parameter is determined. Based on the gradient vector, candidate operating points are determined; Determine whether the candidate operating point meets the preset physical and protocol constraints; If the conditions are met, control instructions are generated to distribute the values ​​of each system operating parameter contained in the candidate operating point to the corresponding system components for execution, and the candidate operating point is used as the target operating point. If the candidate operating point does not meet the requirements, the candidate operating point is corrected to the nearest point that meets the physical and protocol constraints, and control instructions are generated to adjust the values ​​of each system operating parameter to the nearest point, and the nearest point is used as the target operating point.

3. The system according to claim 2, characterized in that, The system operating parameters include one or more of the following: the output frequency of the local oscillator synthesis unit, the transmit power of the millimeter-wave system-on-a-chip (SoC), the receiver gain, and the frequency modulation slope of the linear frequency modulation signal.

4. The system according to claim 3, characterized in that, Based on the difference between the adjusted response interference power value and the initial interference power value, a gradient vector is determined for how the interference power varies with each system operating parameter, including: For each system operating parameter to be optimized at the current operating point, perform the following operations: Keeping other system operating parameters of the current operating point unchanged, the value of the operating parameter of the system to be optimized is increased by a positive disturbance, and the first response disturbance power value is measured. The difference between the first response interference power value and the initial interference power value is divided by the positive disturbance amount to calculate the estimated rate of change of the interference power with respect to the operating parameters of the system to be optimized. Accordingly, after all the operating parameters of the system to be optimized at the current operating point have been traversed, the obtained estimates of the rate of change are combined to obtain the gradient vector of the interference power as a function of each system operating parameter.

5. The system according to claim 4, characterized in that, The difference between the first response interference power value and the initial interference power value is divided by the positive disturbance amount to calculate an estimated rate of change of the interference power with respect to the operating parameters of the system to be optimized, including: Keeping other system operating parameters of the current operating point unchanged, the value of the operating parameter of the system to be optimized is increased by the negative disturbance amount, and the second response disturbance power value is measured. The difference between the first response interference power value and the second response interference power value is divided by twice the disturbance amount to calculate the estimated rate of change of the interference power with respect to the operating parameters of the system to be optimized.

6. The system according to claim 2, characterized in that, The preset physical and protocol constraints include: the operating frequency band of the radio frequency signal after transformation by the frequency conversion layer (20) is in the range of 92-94GHz, and the transmit power of the millimeter-wave system-on-a-chip does not exceed the statutory limit.

7. The system according to claim 2, characterized in that, Based on the gradient vector, candidate operating points are determined, including: The product of the gradient vector and the preset learning rate factor is subtracted from the coordinates of the current working point to obtain the calculation result, and the calculation result is used as the candidate working point.

8. The system according to claim 2, characterized in that, The triggering condition for the cyclic execution of the frequency parameter adaptive adjustment algorithm is: the magnitude of the gradient vector is less than a preset threshold, or the change in the initial interference power value is less than a preset tolerance in a preset number of consecutive iterations.

9. The system according to claim 1, characterized in that, The radar radio frequency system is configured to perform a self-calibration mode. In the self-calibration mode, the baseband processing layer (10) can control the local oscillator synthesis unit and the up mixer group to generate a calibration signal with known power, and send it back to the baseband processing layer (10) via the down mixer group for link gain measurement.

10. The system according to claim 1, characterized in that, The frequency conversion component FCM also includes an integrated temperature sensor.

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