IQ imbalance compensation method, electronic equipment and computer storage medium

Abstract

The invention provides an IQ imbalance compensation method, which is executed by an electronic device, and comprises the following steps: carrying out direct current component removal processing on a first IQ signal of a CIR signal to obtain a second IQ signal, the IQ signal comprising an I signal and a Q signal; sliding on the second IQ signal through a window, for each window position in a plurality of window positions, acquiring an envelope value of a second IQ signal segment in the window, and determining amplitude ratio estimation of a second I signal segment and a second Q signal segment in the window according to the envelope value; and compensating the second Q signal according to the amplitude ratio estimation determined by each window position. According to the scheme disclosed by the invention, high-accuracy IQ imbalance compensation is realized, and the accuracy of phase estimation of the moving object by the CIR is ensured.

Description

Technical Field

[0001] This disclosure relates to the field of communications, and more specifically, to an IQ imbalance compensation method performed by an electronic device, an electronic device, and related computer-readable storage media and program products. Background Technology

[0002] Ultra-wideband (UWB) radar can accurately detect objects in space based on its ultra-wide bandwidth and nanosecond-level pulses. It uses channel impulse response (CIR) estimation to perceive the characteristics of moving objects in the environment. When an object moves, the CIR of the reflected signal near the object's range gate exhibits continuous changes in amplitude and phase. Based on these changes, information such as the object's distance and velocity relative to the radar can be obtained.

[0003] UWB radar demodulates and converts the received radio frequency signal using an analog-to-digital converter (ADC) to obtain a baseband signal (including in-phase (I) and quadrature (Q) components). The baseband signal is then despread and accumulated to obtain a CIR signal (including both I and Q signals). The I and Q signals in the CIR signal may be unbalanced. Significant imbalance can affect the phase information of objects, leading to lower accuracy in determining the number, velocity, and angle of targets.

[0004] Therefore, there is an urgent need for an IQ imbalance compensation method to ensure the accuracy of information such as the number, velocity, and angle of targets determined in UWB radar technology. Summary of the Invention

[0005] The purpose of this disclosure is to provide a technical solution for IQ imbalance compensation, which can at least solve one or more of the above-mentioned or other problems.

[0006] In one aspect of this disclosure, an IQ imbalance compensation method is provided, executed by an electronic device, the method comprising: performing DC component removal processing on a first IQ signal of a CIR signal to obtain a second IQ signal, the IQ signal including an I signal and a Q signal; sliding a window over the second IQ signal, for each of a plurality of window positions, obtaining the envelope value of a second IQ signal segment within the window, and determining an amplitude ratio estimate of the second I signal segment and the second Q signal segment within the window based on the envelope value; and compensating the second Q signal based on the amplitude ratio estimate determined for each window position.

[0007] In some examples, determining the amplitude ratio estimate of the second I signal segment and the second Q signal segment within the window based on the envelope value may include: obtaining the envelope values ​​of I signal sampling points and Q signal sampling points corresponding to the same sampling time within a preset position interval of the window, wherein the length of the preset position interval is equal to the sliding step size of the window; and determining the amplitude ratio estimate based on the envelope values ​​of the I signal sampling points and Q signal sampling points corresponding to the same sampling time.

[0008] In some examples, the preset position range may not include the boundary position of the window.

[0009] In some examples, compensating the second Q signal based on the amplitude ratio estimate determined for each window position may include: for a non-first window position among the plurality of window positions, determining the transition amplitude ratio estimate corresponding to the first plurality of target Q signal sampling points within the window based on the amplitude ratio estimate determined by the previous window position and the amplitude ratio estimate determined by the current window position; multiplying the first plurality of target Q signal sampling points by their corresponding transition amplitude ratio estimates to obtain the compensated plurality of target Q signal sampling points; wherein the length of the plurality of target Q signal sampling points within the window is equal to the sliding step size of the window.

[0010] In some examples, determining the amplitude ratio estimates corresponding to the first plurality of target Q signal sampling points within the window based on the amplitude ratio estimate determined by the previous window position and the amplitude ratio estimate determined by the current window position may include: interpolating between the amplitude ratio estimate determined by the previous window position and the amplitude ratio estimate determined by the current window position to obtain the amplitude ratio estimates corresponding to the first plurality of target Q signal sampling points within the window; the interpolation method includes one or more of the following: linear interpolation, quadratic interpolation, or cubic interpolation.

[0011] In some examples, obtaining the envelope value of the second IQ signal segment within the window may include performing a Hilbert transform and taking the modulus value on the second IQ signal segment within the window to obtain the envelope value.

[0012] In some examples, compensating the second Q signal based on the amplitude ratio estimate determined for each window position may include: for the first window position among the plurality of window positions, multiplying the determined amplitude ratio estimate by the first plurality of target Q signal sampling points within the window to obtain the compensated plurality of target Q signal sampling points; wherein the length of the target Q signal sampling points within the window is equal to the sliding step size of the window.

[0013] In another aspect of this disclosure, an electronic device is provided, comprising: at least one processor; and a memory storing computer-executable instructions, wherein the computer-executable instructions, when executed by the at least one processor, perform the method according to this disclosure.

[0014] In another aspect of this disclosure, a non-volatile computer-readable storage medium is provided storing computer-executable instructions, wherein the computer-executable instructions, when executed by at least one processor, perform the method according to this disclosure.

[0015] In another aspect of this disclosure, a computer program product is provided, including computer-executable instructions, wherein the computer-executable instructions are configured to, when executed by at least one processor, cause the at least one processor to perform the method according to this disclosure.

[0016] By way of example and not limitation, the advantages provided by this disclosure may include one or more of the following advantages and / or other advantages: 1) The amplitude ratio estimate is calculated based on the envelope values ​​of the I and Q signals within the same window position. Since the amplitude ratio estimate is calculated at the same time position of the I and Q signals, the calculation result is less affected by the signal amplitude change, the calculation performance is better, and the calculation accuracy is higher. This makes the calculation result more reflective of the true amplitude ratio estimate of the signal, thus ensuring the accuracy of CIR for phase estimation of moving objects. 2) The Hilbert transform can suppress noise in the second IQ signal band, reduce the impact of noise spikes, and improve the accuracy of amplitude ratio estimation; and 3) The embodiments of this application do not require changes to the underlying design of hardware architecture and parameters, chip protocol parsing firmware, data interface, etc. Instead, IQ imbalance compensation is performed through application layer algorithms, which is relatively simple to implement.

[0017] It should be understood that the technical problems and advantages listed above are merely examples and not limitations of this disclosure. Furthermore, this disclosure is not limited to technical solutions that simultaneously solve all of the above-mentioned technical problems; the technical solutions of this disclosure can be implemented to solve one or more of the above-mentioned or other technical problems, and to provide one or more of the above-mentioned or other advantages. Attached Figure Description

[0018] Figure 1 An example block diagram of a UWB system is presented.

[0019] Figure 2 This is a flowchart illustrating an IQ imbalance compensation method provided in an embodiment of this application.

[0020] Figure 3A flowchart of an IQ imbalance compensation method provided in an embodiment of this application.

[0021] Figure 4 This is a schematic diagram of the original IQ signal of a moving part provided in an embodiment of this application.

[0022] Figure 5 This is a schematic diagram of the FFT amplitude-frequency response of the original signal of the moving part provided in an embodiment of this application.

[0023] Figure 6 This is a schematic diagram of the IQ signal after DC removal from a moving part, provided in an embodiment of this application.

[0024] Figure 7 This is a schematic diagram of the FFT amplitude-frequency response of a moving part to DC signal, provided as an embodiment of this application.

[0025] Figure 8 This is a schematic diagram illustrating the estimation of the amplitude ratio of the IQ signals obtained after applying the IQ imbalance compensation method provided in this application.

[0026] Figure 9 This is a schematic diagram of an IQ signal obtained after IQ imbalance compensation of a moving part signal, as provided in an embodiment of this application.

[0027] Figure 10 This is a schematic diagram of the FFT amplitude-frequency response of a moving part signal after IQ imbalance compensation, provided as an embodiment of this application.

[0028] Figure 11 A schematic block diagram of an electronic device 1100 according to an embodiment of the present disclosure is shown. Detailed Implementation

[0029] The present disclosure will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments shown in the drawings and described below are merely illustrative and are not intended to limit the present disclosure.

[0030] In the context of this disclosure, unless otherwise specifically stated, ordinal numbers such as "first," "second," etc., are used only to distinguish different elements and not to specify their order.

[0031] UWB radar uses CIR signals to detect the characteristics of moving objects in the environment. When an object moves, factors such as the path length and signal strength of the reflected signal change, resulting in continuous changes in amplitude and adjacent phase on the CIR near the object's location within a range gate. The range gate is a time window used to select and analyze reflected signals within a specific distance. For UWB radars equipped with multiple receiving antennas, the object's angle can be calculated using the phase difference of the CIR on different receiving antennas, thus enabling object localization.

[0032] When demodulating the received radio frequency signal, the UWB radar multiplies the radio frequency signal by... and After undergoing analog-to-digital converter (ADC), the baseband signal (including I and Q signals) is obtained. The baseband signal is then despread and accumulated to obtain the CIR signal (also including I and Q signals). Ideally, the amplitudes of the I and Q signals in the CIR signal should be identical and orthogonal (90 degrees outward). However, due to defects in the hardware circuit design, the amplitudes of the I and Q signals may differ, and / or not be ideally orthogonal; this is called IQ imbalance. IQ imbalance affects phase-related detection algorithms, such as target detection algorithms based on Fast Fourier Transform (FFT) and object direction finding algorithms based on multi-antenna phase differences, leading to inaccurate detection results for target quantity, velocity, and angle.

[0033] The following explains in detail why IQ imbalance can cause phase errors. UWB radar detects targets by transmitting and receiving. The CIR signal includes information about all reflective objects in the environment, so continuous CIR measurements are required. The presence of moving objects is determined by detecting changes in the amplitude and phase of the CIR signal at different range gates.

[0034] First, the CIR signal is expressed according to the following formula (1): :

[0035] in, Represents the Dirac function, Indicates different reflection paths, Indicates the total number of reflection paths. Indicates the intensity of reflected signals along different reflection paths. Indicates the phase on different reflection paths, This represents the time delay along different reflection paths. Indicates noise.

[0036] For a single CIR signal Sampling is performed at N points to obtain CIR samples in the fast time dimension. Each sampling point represents a different range gate, and the CIR samples in the fast time dimension include amplitude and phase information at N range gates.

[0037] CIR signal M measurements are performed to obtain CIR samples in the slow time dimension. Each measurement process includes: the UWB radar transmitting a measurement signal, receiving the reflected signal at the same range gate and extracting the CIR, resulting in one CIR, i.e., one... The slow-time dimension CIR sampling includes M CIRs.

[0038] Suppose that when a single target moves at a constant speed relative to the radar at a certain range gate, the target's distance changes over time, causing the phase of the CIR signal received at that range gate to also change continuously over time. This phase change will be reflected in the continuously measured CIR signal, therefore, the IQ signal of the CIR signal will show continuous phase changes in the continuous slow time dimension of that range gate. The expressions for the IQ signal are shown in the following formulas (2) and (3):

[0039]

[0040] in, This represents the initial phase, which is related to the initial positions of objects in the environment. This represents the frequency deviation caused by the motion of an object; when the object is moving at a constant speed... It is a fixed value, but in practice this value usually changes in real time. and Indicates noise.

[0041] Ignoring the interference from noise terms, when When IQ is in equilibrium, estimate the phase. This can be expressed as the following formula (4):

[0042] in, This represents the inverse cotangent function, where the estimated phase change is the same as the actual phase change.

[0043] When IQ is unbalanced, estimate the phase. This can be expressed as the following formula (5):

[0044] At this point, the estimated phase change deviates from the actual phase change. As can be seen from formula (5), the estimation deviation is caused by the IQ imbalance ratio. This is determined by the degree of IQ imbalance. Therefore, the greater the IQ imbalance, the greater the estimation bias, which in turn affects the accuracy of phase-related detection algorithms.

[0045] This application provides an IQ imbalance compensation method, which compensates for IQ imbalance by continuously tracking and estimating the CIR signal, thereby ensuring the accuracy of phase estimation for moving objects.

[0046] The technical solution provided in this application can be applied to Wireless Personal Area Networks (WPANs) based on UWB technology, such as the IEEE 802.15 series protocols, or future generations of UWB WPAN standards, etc., which will not be listed here. The method provided in this application can also be applied to various communication systems, such as Internet of Things (IoT) systems, Vehicle-to-X (V2X) systems, and Narrow Band Internet of Things (NB-IoT) systems. It can also be applied to devices in V2X, IoT nodes and sensors in IoT, smart cameras, smart remote controls, smart water and electricity meters in smart homes, and sensors in smart cities, etc.

[0047] Among them, UWB technology is a new type of wireless communication technology. It uses nanosecond-level non-sinusoidal narrow pulses to transmit data. By modulating impulse pulses with very steep rise and fall times, it can transmit a wide spectrum, giving the signal a bandwidth on the order of gigahertz (GHz). It has advantages such as strong multipath resolution, low power consumption, and strong security.

[0048] The aspects covered in this application can be extended to other networks employing various standards or protocols. For example, Wireless Local Area Networks (WLANs), Bluetooth, and other networks now known or to be developed in the future.

[0049] For example, the method provided in this application can be implemented by a communication device in a wireless communication system. This communication device can be a device involved in a UWB system, or it can include user equipment (UE). The user equipment can include various handheld devices supporting UWB technology, in-vehicle devices (such as automobiles or components installed on automobiles), wearable devices, etc., which will not be listed here. It is understood that the above description of the communication device can be applied to any communication device in the embodiments of this application.

[0050] The following section uses a UWB system as an example to illustrate the communication system architecture adopted in this application. Please refer to... Figure 1 , Figure 1 An exemplary block diagram of a UWB system is presented. Figure 1 As shown, the UWB system 100 includes a transmitter 102 and a receiver 104. As a non-limiting example, the transmitter 102 includes a UWB transmitter baseband (TXBB) 106, a digital-to-analog converter (DAC) 108, a transmitter low-pass filter (LPF) 110, an up-converter 114, a local oscillator (LO) 112, a power amplifier 116, and a transmit antenna 118. In this example, the baseband signal generated by the UWB transmitter baseband 106 is processed by the DAC 108 and the transmitter LPF 110, and then mixed with the local oscillator signal generated by the local oscillator 112 as input to the up-converter 114 to generate an up-converted signal. The up-converted signal is amplified by the power amplifier 116 and then transmitted via the transmit antenna 118. As an example and not a limitation, receiver 104 may include receiving antenna 120, low noise amplifier (LNA) 122, and split the received signal into two paths, I and Q. One path is processed by downconverter 124a, receiver low-pass filter 126a, and analog-to-digital converter (ADC) 128a, and the other path is processed by downconverter 124b, receiver low-pass filter 126b, and analog-to-digital converter (ADC) 128b, and then further digitally processed by UWB receiving baseband.

[0051] Please refer to Figure 2 , Figure 2This is a flowchart illustrating an IQ imbalance compensation method provided in an embodiment of this application. The method can be executed by an electronic device, which can be applied to any of the communication devices described above. The steps included in the method 200 are as follows.

[0052] Step 202: Perform DC component removal processing on the first IQ signal of the CIR signal to obtain the second IQ signal, which includes I signal and Q signal.

[0053] The CIR signal can be the CIR sample value corresponding to any sampling point among M sampling points (slow time dimension sampling) under any distance gate. The CIR signal can be represented as The sampled values ​​of the first I signal and the first Q signal can be expressed as follows: and , .

[0054] In one implementation, the DC component in the first I signal and the first Q signal can be removed by low-pass filtering. For example, the first I signal and the first Q signal can be input into a Finite Impulse Response (FIR) low-pass filter to remove the DC component from these two signals.

[0055] In one implementation, the mean values ​​of the first I signal and the first Q signal can also be calculated. Then, the mean value of the first I signal is subtracted from each sample value in the first I signal, and the mean value of the first Q signal is subtracted from each sample value in the first Q signal, in order to remove the DC component from these two signals.

[0056] Taking low-pass filtering as an example, the second IQ signal is obtained by low-pass filtering the first IQ signal. It can be expressed as the following formula (6). Including the second I signal Second Q signal :

[0057] in, This represents the impulse response (i.e., tap coefficient) of the FIR low-pass filter. This indicates the number of taps in the filter.

[0058] Step 204: Slide the window over the second IQ signal. For each of the multiple window positions, obtain the envelope value of the second IQ signal segment within the window, and determine the amplitude ratio estimate of the second I signal segment and the second Q signal segment within the window based on the envelope value.

[0059] The window has a fixed length. During the window's sliding motion, the portion of the second IQ signal located within the window at each window position is called the second IQ signal segment. The envelope value of the second IQ signal segment is the instantaneous amplitude of the second IQ signal segment at each sampling time.

[0060] In obtaining the envelope value of the second IQ signal segment, one implementation involves performing a Hilbert transform and taking the modulus of the second IQ signal segment within the window to obtain its envelope value. For example, the envelope value can be obtained by averaging the modulus values ​​of the signal after performing the Hilbert transform on the second IQ signal segment.

[0061] The Hilbert transform is a linear operator that converts a real-valued signal into a signal with the same amplitude spectrum but a phase spectrum shifted by -90°. Specifically, it shifts the positive frequency components of the signal by -90° and the negative frequency components by +90°. After the Hilbert transform, the instantaneous amplitude (i.e., the envelope value) at each sampling time can be extracted.

[0062] In this embodiment, the Hilbert transform can suppress noise in the second IQ signal segment, reduce the impact of noise spikes, and improve the accuracy of amplitude ratio estimation.

[0063] When determining the amplitude ratio estimate of the second I signal segment and the second Q signal segment within a window based on the envelope values, one implementation involves obtaining the envelope values ​​of the I signal sampling points and Q signal sampling points corresponding to the same sampling time within a preset position interval of the window. Then, the amplitude ratio estimate is determined based on the envelope values ​​of the I signal sampling points and Q signal sampling points corresponding to the same sampling time.

[0064] For example, the ratio of the averaged envelope values ​​of the I signal sampling points and the Q signal sampling points can be used to determine the amplitude ratio estimate of the second I signal segment and the second Q signal segment. Averaging can further reduce the impact of noise spikes.

[0065] For example, suppose the preset position range is within the window. arrive common There are 10 sampling points, meaning the length of the preset location interval is 1000. Number of sampling points (the window step size is also correspondingly 1) (if there are 1 sampling point), then the length of the preset position interval is expressed by the following formula (7):

[0066] The envelope value of the second I signal segment is expressed as: The envelope value of the second Q signal segment is expressed as: Then the second I signal segment The process of averaging the envelope values ​​of each I signal sampling point is expressed by the following formula (8), and the second Q signal segment... The process of averaging the envelope values ​​of each Q signal sampling point is expressed by the following formula (9):

[0067]

[0068] in, Indicates the initial starting position of the window.

[0069] Amplitude ratio estimation of the second I signal segment and the second Q signal segment It can be expressed as the following formula (10):

[0070] In this embodiment, by sliding the window, the amplitude ratio estimates of multiple second I signal segments and second Q signal segments can be obtained. .in, , It can represent the number of amplitude estimations, the number of window moves + 1, or the number of different window positions.

[0071] In this embodiment, the length of the preset position interval can be equal to the sliding step size of the window. The sliding step size and the length of the preset position interval can be represented by the number of sampling points; for example, the number of sampling points within the preset position interval can be... Each time the window moves One sampling point.

[0072] The envelope value of the second IQ signal segment obtained after Hilbert transformation may be distorted at the window boundaries. To ensure the accuracy of the envelope value, the number of sampling points moved by the window each time should not be too large. However, the smaller the number of sampling points moved by the window each time, the more times the Hilbert transformation needs to be performed, resulting in higher computational complexity.

[0073] In this embodiment, the ratio of the length of the preset position interval to the window length can be within a target range, such as [1 / 4, 3 / 4], [1 / 3, 5 / 6], or [2 / 5, 4 / 5], etc. This embodiment does not limit the specific range. This ensures that the number of sampling points moved by the window each time is moderate, guaranteeing the accuracy of the envelope value while minimizing the number of Hilbert transform operations and reducing computational complexity.

[0074] For example, the preset position interval may exclude the window boundary positions. This avoids distorted envelope values ​​from participating in the amplitude ratio estimation of the second I signal segment and the second Q signal segment, thus ensuring the accuracy of the amplitude ratio estimation. For instance, the preset position interval may be located at the middle position of the window.

[0075] Step 206: Compensate the second Q signal based on the amplitude ratio estimate determined for each window position.

[0076] For the first window position among multiple window positions, the amplitude ratio estimate determined at that window position can be multiplied by the first multiple target Q signal sampling points within the window to obtain the compensated multiple target Q signal sampling points. The length of the target Q signal sampling points within the window is the window's sliding step size; that is, the number of target Q signal sampling points within the window is the same as the number of sampling points moved by the window each time.

[0077] For a non-first window position among multiple window positions, one implementation method is to directly multiply the amplitude ratio estimate determined by the window position by the first multiple target Q signal sampling points within the window to obtain the compensated multiple target Q signal sampling points.

[0078] In one implementation, the second Q signal segment within the window can be compensated by using transitional amplitude ratio estimates from the amplitude ratio estimate of the previous window position to the amplitude ratio estimate of the current window position. This maintains signal continuity while achieving IQ dynamic balance and avoids the introduction of other high-frequency components due to IQ compensation.

[0079] For example, the transition amplitude ratio estimates corresponding to the first multiple target Q signal sampling points within the window can be determined based on the amplitude ratio estimate determined by the previous window position and the amplitude ratio estimate determined by the current window position. Then, each of the first multiple target Q signal sampling points is multiplied by its corresponding transition amplitude ratio estimate to obtain the compensated multiple target Q signal sampling points. The length of the multiple target Q signal sampling points within the window is the sliding step size of the window.

[0080] Between the amplitude ratio estimate determined by the previous window position and the amplitude ratio estimate determined by the current window position, the electronic device can perform interpolation to obtain the amplitude ratio estimates corresponding to the first multiple target Q signal sampling points within the window. For example, the electronic device can use interpolation for comparative transitions.

[0081] The interpolation methods include, but are not limited to, one or more of the following: linear interpolation, quadratic interpolation, or cubic interpolation.

[0082] The following provides a detailed explanation of the compensation method, which involves adjusting the position of the x-th window. The sampling points are denoted as the xth signal segment.

[0083] For the first segment of the Q signal (i.e., the target Q signal sampling point at the first window position), the amplitude ratio is estimated. This can be expressed as the following formula (11):

[0084] Will With the first Q signal Multiply to obtain the compensated Q-channel signal This process is expressed by the following formula (12):

[0085] in, .

[0086] For the subsequent k-th segment of the signal, use from arrive Transitional Each transition amplitude ratio estimate is used for the k-th segment of the Q-channel signal. Each target Q signal sampling point is compensated sequentially. Taking the proportional linear interpolation method as an example, the transition amplitude is compared to the estimated... This can be expressed as the following formula (13):

[0087] Each With the first Q signal Multiply the corresponding target Q signal sampling points to obtain the compensated Q-channel signal. This process is expressed by the following formula (14):

[0088] in, .

[0089] The following flowchart illustrates the process of determining the amplitude ratio estimation for each window position. Please refer to it. Figure 3 , Figure 3 A flowchart of an IQ imbalance compensation method provided in this application embodiment is shown below, and the method 300 includes the following steps.

[0090] Step 302: Obtain the CIR signal.

[0091] Step 304: Perform low-pass filtering on the first IQ signal of the CIR signal to obtain the second IQ signal, which includes the I signal and the Q signal.

[0092] This process can be referred to in the aforementioned process 202, and will not be repeated here.

[0093] Step 306: Determine the second IQ signal segment within the current window position window.

[0094] This process can be referred to in the aforementioned process 204, and will not be repeated here.

[0095] Step 308: Perform Hilbert transform and modulus on the second IQ signal segment within the window to obtain the envelope value of the second IQ signal segment.

[0096] This process can be referred to in the aforementioned process 204, and will not be repeated here.

[0097] Step 310: Based on the envelope value, determine the amplitude ratio estimate of the second I signal segment and the second Q signal segment within the window.

[0098] This process can be referred to in the aforementioned process 204, and will not be repeated here.

[0099] Step 312: Use the amplitude ratio estimate of the window position to compensate for the first multiple target Q signal sampling points within the window.

[0100] Step 314: Determine if the window sliding has ended.

[0101] For example, if the right boundary index of the window is greater than or equal to the total length of the second IQ signal, then the window sliding is determined to be over.

[0102] If the window slide is not finished, proceed to steps 316 to 324. If the window slide is finished, end the entire process.

[0103] Step 316: Update the second IQ signal segment in the window.

[0104] Step 318: Perform Hilbert transform and modulus on the second IQ signal segment within the current window to obtain the envelope value of the second IQ signal segment.

[0105] This process can be referred to in the aforementioned process 204, and will not be repeated here.

[0106] Step 320: Based on the envelope value, determine the amplitude ratio estimate of the second I signal segment and the second Q signal segment within the current window.

[0107] This process can be referred to in the aforementioned process 204, and will not be repeated here.

[0108] Step 322: Determine the transition amplitude ratio estimates from the amplitude ratio estimate of the previous window position to the amplitude ratio estimate of the current window position.

[0109] This process can be referred to in the aforementioned process 206, and will not be repeated here.

[0110] Step 324: Use various transition amplitude ratio estimates to compensate for the first multiple target Q signal sampling points within the current window.

[0111] The following describes the signal after IQ compensation using the IQ imbalance compensation method described in the embodiments of this application. For example, when the detection frame rate is 1000Hz, CIR is acquired for an object approaching the radar at a constant speed of 1m / s. Sampling points within 5 seconds at a certain range gate are taken, and the real and imaginary parts of the motion signal are as follows: Figure 4 As shown.

[0112] The signals sampled at the sampling points include motion signals and other signals (such as noise signals). The phase of the motion signal changes continuously and regularly, and it contains information about the target's motion. If there is an IQ imbalance, it will affect the characteristics of the phase change of the motion signal, and thus affect velocity measurement, angle measurement, target quantity determination, etc. For non-motion signals, their phase change is irregular, so their IQ imbalance will not affect the measurement results. Therefore, compensation can be performed only for the motion signal.

[0113] An FFT is performed on the motion signal (sampling points 2361 to 2616), and the FFT amplitude-frequency response is as follows: Figure 5 As shown. By Figure 5 It can be seen that due to the IQ imbalance, in addition to the positive frequency component generated by the object's proximity, there is also a strong negative frequency component in the FFT amplitude-frequency response. This may lead to one target being judged as two targets, affecting the target detection result.

[0114] The motion signal is passed through an FIR low-pass filter to remove the DC component of the IQ signal, resulting in the IQ signals as follows: Figure 6 As shown. After passing through the FIR low-pass filter, the motion signal will have a fixed number of delays. This embodiment of the application uses a fixed delay of 172 points as an example for illustration. Therefore, the subsequent sampling point range is 2533 to 2788.

[0115] An FFT is performed on the motion signal (sampling points 2533 to 2788), and the FFT amplitude-frequency response is as follows: Figure 7 As shown. By Figure 7 It can be seen that the DC component has been removed.

[0116] Then, the IQ imbalance compensation method provided in this application is applied to the DC-free signal, and the ratio image of the I and Q signals is as follows: Figure 8 As shown. Figure 8 In the diagram, the red dashed box represents the IQ amplitude ratio estimate at the motion signal, while the area outside the red dashed box represents the IQ amplitude ratio estimate from the noise component.

[0117] The signal after IQ balance is as follows Figure 9As shown, the amplitudes of the I and Q signals are basically the same at this point. Performing an FFT on the IQ balanced signal (sampling points 2533 to 2788) yields the following FFT amplitude-frequency response: Figure 10 As shown. By Figure 10 It can be seen that at this point, the FFT amplitude-frequency response only has a positive frequency component, eliminating the influence of IQ imbalance.

[0118] In summary, the IQ imbalance compensation method provided in this application calculates the amplitude ratio estimate based on the envelope values ​​of the I and Q signals within the same window position. Since the amplitude ratio estimate is calculated at the same time position of the I and Q signals, the calculation result is less affected by changes in signal amplitude, resulting in better calculation performance and higher calculation accuracy. This makes the calculation result more reflective of the true amplitude ratio estimate of the signal, thereby ensuring the accuracy of CIR phase estimation for moving objects.

[0119] Furthermore, the embodiments of this application do not require changes to the underlying design of the hardware architecture and parameters, chip protocol parsing firmware, data interface, etc. Instead, they use application layer algorithms to perform IQ imbalance compensation, which is relatively simple to implement.

[0120] In one aspect of this disclosure, an electronic device is provided, comprising: at least one processor; and a memory storing computer-executable instructions, wherein the computer-executable instructions, when executed by the at least one processor, perform the method according to this disclosure.

[0121] As a non-restrictive example, Figure 11 A schematic block diagram of an electronic device 1100 according to one embodiment of the present disclosure is shown. By way of example and not limitation, the electronic device 1100 may include one or more processors 1102, volatile memory 1104 such as random access memory (RAM), non-volatile memory (NVM) 1106, input device 1108, and bus 1110. It should be understood that... Figure 11 The electronic components shown can be integrated into one or more chips or modules including a microcontroller unit (MCU), a system-on-chip (SoC), etc. Volatile memory 1104 and / or non-volatile memory 1106 may store computer instructions that, when executed by the one or more processors, cause the one or more processors to perform any of the methods according to this disclosure.

[0122] In another aspect of this disclosure, a non-volatile computer-readable storage medium is provided storing computer-executable instructions, wherein the computer-executable instructions, when executed by at least one processor, perform the method according to this disclosure.

[0123] In another aspect of this disclosure, a computer program product is provided, including computer-executable instructions, wherein the computer-executable instructions are configured to, when executed by at least one processor, cause the at least one processor to perform the method according to this disclosure.

[0124] While various embodiments of various aspects of this disclosure have been described for the purposes of this disclosure, they should not be construed as limiting the teachings of this disclosure to these embodiments. Features disclosed in one specific embodiment are not limited to that embodiment, but can be combined with features disclosed in different embodiments. For example, one or more features and / or functions according to the scheme described in one embodiment can also be applied individually, in combination, or holistically to another embodiment. Furthermore, various embodiments of various aspects of this disclosure can be implemented independently or in different combinations. Those skilled in the art will understand that many more possible alternative implementations and variations exist, and various changes and modifications can be made to the above structure without departing from the protection scope of this disclosure.

Claims

1. An IQ imbalance compensation method, performed by an electronic device, the method comprising: The DC component of the first IQ signal of the channel impulse response (CIR) signal is removed to obtain the second IQ signal, which includes an I signal and a Q signal. By sliding a window over the second IQ signal, for each of the multiple window positions, the envelope value of the second IQ signal segment within the window is obtained, and the amplitude ratio estimate of the second I signal segment and the second Q signal segment within the window is determined based on the envelope value. The second Q signal is compensated based on the amplitude ratio estimate determined for each window position.

2. The method according to claim 1, characterized in that, The step of determining the amplitude ratio estimate of the second I signal segment and the second Q signal segment within the window based on the envelope value includes: Obtain the envelope values ​​of the I signal sampling points and Q signal sampling points corresponding to the same sampling time within a preset position interval of the window, wherein the length of the preset position interval is equal to the sliding step size of the window; The amplitude ratio estimate is determined based on the envelope values ​​of the I signal sampling points and Q signal sampling points corresponding to the same sampling time.

3. The method according to claim 2, characterized in that, The preset position range does not include the boundary position of the window.

4. The method according to any one of claims 1 to 3, characterized in that, The compensation of the second Q signal based on the amplitude ratio estimation determined according to each window position includes: For a non-first window position among the plurality of window positions, based on the amplitude ratio estimate determined by the previous window position and the amplitude ratio estimate determined by the current window position, the transition amplitude ratio estimates corresponding to the first plurality of target Q signal sampling points within the window are determined respectively; the first plurality of target Q signal sampling points are multiplied by the corresponding transition amplitude ratio estimates respectively to obtain the compensated plurality of target Q signal sampling points; Wherein, the length of the plurality of target Q signal sampling points within the window is equal to the sliding step size of the window.

5. The method according to claim 4, characterized in that, The determination of the amplitude ratio estimates corresponding to the first plurality of target Q signal sampling points within the window, based on the amplitude ratio estimate determined by the previous window position and the amplitude ratio estimate determined by the current window position, includes: Interpolation is performed between the amplitude ratio estimate determined by the previous window position and the amplitude ratio estimate determined by the current window position to obtain the amplitude ratio estimates corresponding to the first multiple target Q signal sampling points within the window; The interpolation method includes one or more of the following: linear interpolation, quadratic interpolation, or cubic interpolation.

6. The method according to any one of claims 1 to 3, characterized in that, The step of obtaining the envelope value of the second IQ signal segment within the window includes: The envelope value is obtained by performing a Hilbert transform and taking the modulus value on the second IQ signal segment within the window.

7. The method according to any one of claims 1 to 3, characterized in that, The compensation of the second Q signal based on the amplitude ratio estimation determined according to each window position includes: For the first window position among the plurality of window positions, the determined amplitude ratio estimate is multiplied by the first plurality of target Q signal sampling points within the window to obtain the compensated plurality of target Q signal sampling points; Wherein, the length of the target Q signal sampling point within the window is equal to the sliding step size of the window.

8. An electronic device, comprising: At least one processor; as well as A memory storing computer-executable instructions, wherein the computer-executable instructions, when executed by the at least one processor, perform the method according to any one of claims 1 to 7.

9. A non-volatile computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions, when executed by at least one processor, perform the method according to any one of claims 1 to 7.

10. A computer program product comprising computer-executable instructions, wherein the computer-executable instructions are configured, when executed by at least one processor, to cause the at least one processor to perform the method according to any one of claims 1 to 7.

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