A method and apparatus for real-time image suppression of digital array transmit channels

Abstract

This invention relates to the field of signal processing technology in wireless communication systems, and discloses a method and apparatus for real-time image suppression in a digital array transmission channel. Through digital signal processing technology, this invention achieves real-time online image suppression with adaptive tracking without service interruption, effectively overcoming the inherent drawbacks of traditional hardware calibration, such as high cost, difficulty in handling parameter drift, and the need for service interruption for external calibration. Implemented in the digital domain, this invention offers significant advantages such as high accuracy and ease of integration and upgrades, providing crucial assurance for the long-term stable and high-performance operation of digital array transmission systems in dynamic environments.

Description

Technical Field

[0001] This invention relates to the field of signal processing technology in wireless communication systems, and in particular to a method and apparatus for real-time image suppression of digital array transmission channels. Background Technology

[0002] Digital array antennas, especially digital transmit arrays employing direct up-conversion architectures, are widely used in satellite communications, radar systems, and 5G / 6G mobile communications due to their advantages such as flexible structure and ease of integration. However, this type of architecture faces a key challenge in practical implementation: because it is difficult to achieve ideal symmetry in the physical implementation of the I / Q modulators, non-ideal factors such as amplitude imbalance (inconsistent gain between the I and Q paths) and phase non-orthogonality (a 90° phase difference between the two paths) are inevitably introduced. These I / Q mismatch problems cause interference components to be generated at the mirror frequency of the modulated signal, i.e., image interference. If not suppressed, image interference will significantly degrade signal quality, increase the system bit error rate, and directly affect the accuracy and efficiency of beamforming performance.

[0003] Currently, existing suppression methods for the image interference problem caused by the aforementioned I / Q mismatch can be mainly divided into two categories:

[0004] One approach is the hardware precision calibration method, which involves selecting high-performance, highly compatible components and combining them with precise circuit design to minimize the inconsistency between the I and Q paths at the physical level. However, this method places extremely high demands on the components, increasing costs accordingly, and it is difficult to compensate for parameter changes caused by time-varying factors such as component aging and temperature drift, thus limiting its adaptability.

[0005] The second method is the external calibration source injection method. This typically involves injecting a known test signal (such as a single-tone signal) through an additional calibration network during system downtime (e.g., startup) to estimate I / Q mismatch parameters and calculate correction coefficients. While this method can improve image rejection to some extent, it relies on interrupting normal communication processes and cannot achieve real-time online calibration. Furthermore, introducing additional calibration hardware increases system complexity and calibration time, making it difficult to meet real-time requirements in dynamic, time-varying environments.

[0006] In view of this, there is an urgent need in the field for a solution that can adapt to changes in the working environment in real time and effectively suppress mirror interference without interrupting business operations or relying on high-cost hardware. Summary of the Invention

[0007] This invention provides a method and apparatus for real-time image suppression of digital array transmission channels to overcome the deficiencies of existing technologies.

[0008] This invention provides a real-time image suppression method for a digital array transmit channel, comprising: The pipelined digital baseband complex signal is received from the digital baseband unit through the digital array transmit channel, and a feedback signal is extracted at the antenna of the digital array transmit channel. The pipelined digital baseband complex signal is preset to a frequency point where no signal is transmitted, and the feedback signal is the signal with image interference after the pipelined digital baseband complex signal passes through the I / Q modulator of the digital array transmit channel. Estimate the compensation parameters based on the feedback signals; Based on the compensation parameters, the predistortion compensation matrix is ​​constructed in real time; The pre-distortion compensation matrix is ​​used to pre-compensate the new pipelined service digital baseband complex signal received from the digital baseband unit by the digital array transmit channel, so as to preemptively offset the distortion that the I / Q modulator of the digital array transmit channel will introduce into the new pipelined service digital baseband complex signal, and realize real-time image suppression.

[0009] A real-time image suppression method for a digital array transmit channel provided by the present invention includes: The output signal obtained by the I / Q modulator of the digital baseband complex signal of the pipeline operation is modeled to obtain the compensation parameters to be estimated. The ideal streaming digital baseband complex signal is a discrete digital signal, denoted as . ,satisfy = +jQ In the formula, n is the discrete sampling number. express The in-phase component, i.e., the real part, Q express The orthogonal components, i.e., the imaginary part; Discrete digital signals After digital-to-analog conversion, a continuous-time domain analog in-phase signal is obtained. Orthogonal signals from analog And input to the I / Q modulator; The output signal obtained by the I / Q modulator from the digital baseband complex signal of the pipelined service is modeled as follows: , In the formula, This represents the output signal obtained by passing an ideal streaming digital baseband complex signal through a non-ideal I / Q modulator. Indicates the amplitude mismatch factor. Indicates the phase error angle. Indicates the time independent variable of the signal flow; The compensation parameters to be estimated include the amplitude mismatch factor. and phase error angle .

[0010] According to the present invention, a real-time image suppression method for a digital array transmit channel, wherein receiving pipelined digital baseband complex signals from a digital baseband unit through a digital array transmit channel and extracting feedback signals at the antenna of the digital array transmit channel includes: A frequency point is selected in the in-band spectrum of the pipelined digital baseband complex signal and the signal at that frequency point is set to zero. When the pipelined digital baseband complex signal with the signal at that frequency point set to zero passes through the I / Q modulator, its corresponding feedback signal is taken out at the antenna of the digital array transmission channel. This feedback signal is the signal of image interference that exists after the pipelined digital baseband complex signal passes through the I / Q modulator of the digital array transmission channel.

[0011] According to the present invention, a real-time image suppression method for a digital array transmit channel, wherein estimating compensation parameters based on feedback signals includes: The amplitude mismatch factor is estimated based on the relative power of the main signal frequency and the mirror frequency in the feedback signal, as well as the phase relationship between the main signal frequency and the mirror frequency. and phase error angle .

[0012] According to the present invention, a real-time image suppression method for a digital array transmit channel includes pre-compensating the new pipelined digital baseband complex signal received by the digital array transmit channel from the digital baseband unit using a pre-distortion compensation matrix, comprising: Before the new digital baseband complex signal undergoes digital-to-analog conversion, a pre-compensation expression is used to pre-compensate the new pipelined service digital baseband complex signal received from the digital baseband unit by the digital array transmit channel using a pre-distortion compensation matrix. The pre-compensation expression is as follows: , In the formula, This represents the signal after pre-compensation of the new pipelined digital baseband complex signal received from the digital baseband unit by the digital array transmit channel using a pre-distortion compensation matrix. , These represent real-time digital baseband complex signals. The real and imaginary parts, with the superscript T indicating transpose. This represents the predistortion compensation matrix.

[0013] The real-time image suppression method for a digital array transmit channel provided by the present invention further includes: The digital baseband complex signal received by the digital array transmission channel and the radio frequency signal transmitted after image suppression are acquired. The image rejection ratio is obtained based on the digital baseband complex signal received by the digital array transmission channel and the radio frequency signal transmitted after image rejection. The image suppression ratio is used as a condition to set whether to re-estimate the compensation parameters, thereby achieving adaptive optimization of the predistortion compensation matrix.

[0014] The real-time image suppression method for a digital array transmit channel provided by the present invention further includes: Set the time period for re-estimating compensation parameters to update the predistortion compensation matrix periodically.

[0015] The present invention also provides a real-time image suppression device for a digital array transmission channel, comprising a digital baseband unit, a digital array antenna, and a main control unit. The digital array antenna includes a digital-to-analog converter front-end, an I / Q modulator, a power amplifier, and an antenna. The main control unit includes a receiver and a compensation module. A coupler and an RF feedback line are provided between the antenna of the digital array antenna and the receiver of the main control unit. The digital baseband unit is used to generate the pipelined digital baseband complex signal, the digital array antenna is used to receive, process and transmit the pipelined digital baseband complex signal, and the main control unit is used to execute the steps of the real-time image suppression method for the digital array transmission channel described above, so as to perform real-time image suppression on the pipelined digital baseband complex signal received by the digital array antenna.

[0016] The present invention also provides an electronic device, including a processor and a memory storing a computer program, wherein the processor executes the computer program to implement any of the above-described methods for real-time image suppression of digital array transmission channels.

[0017] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described methods for real-time image suppression of digital array transmission channels.

[0018] The present invention also provides a computer program product, the computer program product including a computer program, the computer program being stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer is able to execute any of the above-described digital array transmit channel real-time image suppression methods.

[0019] The present invention provides a method and apparatus for real-time image suppression of a digital array transmission channel, which can bring at least the following beneficial effects: This invention overcomes the limitations of traditional external calibration source injection methods, which require interruption of normal communication and rely on idle periods. It can use the actual service signal itself for continuous and online parameter estimation and correction without the need to inject a dedicated calibration signal, effectively ensuring the continuity of communication and the real-time performance of the system.

[0020] This invention effectively solves the problem of time-varying parameter drift that cannot be overcome by hardware precision calibration methods. It can dynamically track and compensate for I / Q parameter drift caused by factors such as temperature changes and device aging, enabling the device to maintain high-performance image suppression capability for a long time in dynamically changing working environments.

[0021] This invention uses advanced digital signal processing for parameter estimation and compensation, avoiding the shortcomings of limited accuracy and poor consistency of analog circuit correction. This method can bring higher correction accuracy and repeatability, thereby significantly improving the overall performance of image suppression.

[0022] The core calibration process of this invention is mainly implemented in the digital domain (such as FPGA or DSP), without the need to introduce complex external calibration networks and high-frequency precision hardware. This can greatly reduce the additional hardware complexity and cost of the device, and make this invention easy to implement in existing digital array systems through software upgrades or configurations, thus facilitating its widespread application. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is one of the flowcharts illustrating a real-time image suppression method for a digital array transmission channel provided by the present invention.

[0025] Figure 2 This is the second flowchart illustrating a real-time image suppression method for a digital array transmission channel provided by the present invention.

[0026] Figure 3 This is a schematic diagram of the structure of a real-time image suppression device for a digital array transmission channel provided by the present invention.

[0027] Figure 4 The image shows the signal spectrum before and after distortion.

[0028] Figure 5 This is a schematic diagram of the simulation calibration results. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, embodiments of this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. In the description of this invention, it should be understood that the terminology used is for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] The present invention provides a real-time image suppression method for a digital array transmit channel, the principle of which is shown in the block diagram below. Figure 1 and 2 As shown, the upper layer has a digital baseband unit that transmits normal service signals. Initially, the predistortion compensation matrix is ​​set to an identity matrix by default, and no I / Q compensation is performed. The signal is converted into an analog signal by a DAC and an analog front end, and then I / Q modulation is performed (amplitude and phase imbalance in I / Q modulation will cause image mirroring). The signal is then transmitted to the air interface by a power amplifier and antenna. The antenna is connected to a feedback line by a coupler to extract the signal. Based on the extracted feedback signal, parameter estimation and adaptive monitoring are performed, and the predistortion matrix is ​​updated in real time to compensate for the normal service signal. Figure 3 The diagram shows an apparatus for real-time mirror calibration of a digital array antenna using the present invention, wherein the digital baseband complex signal is provided by an upper-layer digital baseband unit. The digital array antenna is connected to the main control unit via a coupler and an RF feedback line, and the feedback signal is acquired, monitored, parameter estimated, and compensated in the main control unit.

[0031] The present invention provides a real-time image suppression method for a digital array transmit channel, which may specifically include the following steps: S1. Model the output signal obtained by the I / Q modulator from the pipelined digital baseband complex signal to obtain the compensation parameters to be estimated. The ideal pipelined digital baseband complex signal is a discrete digital signal, denoted as... ,satisfy = +jQ In the formula, n is the discrete sampling number. express The in-phase component, i.e., the real part, Q The orthogonal components, i.e., the imaginary part; discrete digital signal After digital-to-analog conversion, a continuous-time domain analog in-phase signal is obtained. Orthogonal signals from analog The signal is input to the I / Q modulator; image interference is caused by the I / Q imbalance effect, so it can be described using a mathematical model. In this embodiment, the output signal obtained by the digital baseband complex signal through the I / Q modulator is modeled as follows: , In the formula, This represents the output signal obtained by passing an ideal streaming digital baseband complex signal through a non-ideal I / Q modulator. Indicates the amplitude mismatch factor. Indicates the phase error angle. Indicates the time independent variable of the signal flow; The compensation parameters to be estimated include the amplitude mismatch factor. and phase error angle .

[0032] S2. Receive the pipelined digital baseband complex signal from the digital baseband unit through the digital array transmission channel, and extract the feedback signal at the antenna of the digital array transmission channel. The pipelined digital baseband complex signal is preset to have a frequency point where no signal is transmitted. The feedback signal is the signal with image interference after the pipelined digital baseband complex signal passes through the I / Q modulator of the digital array transmission channel.

[0033] In one embodiment, a frequency point can be selected on the in-band spectrum of the pipelined digital baseband complex signal and the signal at that frequency point can be set to zero (i.e., nothing is transmitted on that frequency point). When the pipelined digital baseband complex signal with the signal at that frequency point set to zero passes through the I / Q modulator, its corresponding feedback signal is taken out at the antenna of the digital array transmission channel. This feedback signal is the signal of image interference that exists after the pipelined digital baseband complex signal passes through the I / Q modulator of the digital array transmission channel.

[0034] This embodiment abandons the traditional dedicated calibration signal and can directly use the normally transmitted service signal for parameter estimation. Specifically, a frequency point is selected within the in-band spectrum of the transmitted signal, and nothing is transmitted at that frequency point (i.e., the signal at that frequency point is set to zero). After this... After modulation, the mirror image of the symmetrical service signal within the signal band will fall at that frequency point. This customized operation occupies negligible service signal spectrum resources, causing no significant waste of service signal spectrum resources. Furthermore, the baseband can flexibly control the location of the signal mirror frequency point based on the service signal. The signal is connected to the receiver via a cable through a coupler to the transmitting antenna. The receiver performs digital down-conversion, sampling, and analyzes the spectrum of the received signal. Simultaneously, the energy of the mirror frequency point corresponding to that frequency point is observed based on the spectrum. By comparing the relative power of the main signal frequency point and the mirror frequency point, as well as their phase relationship, the current amplitude mismatch factor can be calculated. and phase error angle .

[0035] S3. Estimate the compensation parameters based on the feedback signal.

[0036] In one embodiment, the amplitude mismatch factor can be estimated based on the relative power of the main signal frequency and the mirror frequency in the feedback signal, as well as the phase relationship between the main signal frequency and the mirror frequency. and phase error angle .

[0037] S4. Construct the predistortion compensation matrix in real time based on the compensation parameters.

[0038] S5. The pre-distortion compensation matrix is ​​used to pre-compensate the new pipelined service digital baseband complex signal received from the digital baseband unit by the digital array transmit channel, so as to pre-cancele the distortion that the I / Q modulator of the digital array transmit channel will introduce into the new pipelined service digital baseband complex signal, realize real-time image suppression, and make the image components in the final transmitted signal spectrum significantly canceled.

[0039] In one embodiment, before the new digital baseband complex signal undergoes digital-to-analog conversion (DAC), the new pipelined digital baseband complex signal received from the digital baseband unit by the digital array transmit channel can be pre-compensated using a pre-distortion compensation matrix via a pre-compensation expression, wherein the pre-compensation expression is: , In the formula, This represents the signal after pre-compensation of the new pipelined digital baseband complex signal received from the digital baseband unit by the digital array transmit channel using a pre-distortion compensation matrix. , These represent real-time digital baseband complex signals. The real and imaginary parts, with the superscript T indicating transpose. This represents the predistortion compensation matrix.

[0040] S6. Re-estimate the compensation parameters according to the preset conditions to update the predistortion compensation matrix in real time, so as to adapt to the changes in channel characteristics caused by environmental changes (such as temperature drift) and achieve fully adaptive closed-loop mirror correction.

[0041] In one embodiment, the digital baseband complex signal received by the digital array transmission channel and the radio frequency signal transmitted after image suppression can be acquired through a coupling link. After downconversion, their spectrum is analyzed, the image suppression ratio is quantitatively calculated, and the time for re-estimating the compensation parameters is set using the image suppression ratio as a condition (for example, the compensation parameters need to be re-estimated when the image suppression ratio is within a certain range) to dynamically adjust the predistortion compensation matrix.

[0042] In one embodiment, a time period for re-estimating the compensation parameters can also be set to periodically update the predistortion compensation matrix.

[0043] The following provides a specific embodiment to describe a real-time image suppression method for a digital array transmission channel provided by the present invention.

[0044] This embodiment uses an FPGA as a digital signal processing platform as an example.

[0045] I. System Initialization: After the system is powered on, an initial calibration can be performed. For example, a 2.5MHz single-tone signal can be generated as the initial calibration signal, and an initial set of [signals] can be estimated using this invention. and And construct the initial pre-correction matrix M0.

[0046] 1. Normal Business Mode - Real-time Parameter Estimation: The system switches to normal service mode, for example, transmitting a broadband service signal (pipeline service digital baseband complex signal) with a bandwidth of 10MHz and a sampling rate of 15.36MHz. It then selects a specific frequency point in the spectrum where no signal is transmitted, setting it to zero. This is done to allow the signal to pass through... After the modulator is distorted, a complete mirror image of the signal at its symmetrical frequency points is obtained, such as... Figure 4 As shown in the figure above, the normalized baseband spectrum before distortion is shown. Assuming no signal is placed at the 3.12MHz frequency point (other suitable frequencies can be dynamically adjusted and selected), after distortion, as shown in the figure below, a mirror spectrum of the -3.12MHz signal appears at the 3.12MHz frequency point.

[0047] The coupled feedback acquires the transmitted signal (feedback signal), and the acquired digital signal is y. y is fed to the parameter estimation module for processing and real-time monitoring of the signal image. First, it passes through... The corresponding frequency domain signal yf of the time domain signal y is obtained: ; Except for the image and signal frequency points at ±3.12MHz, all other frequency points in the yf spectrum are set to zero: ; The inverse Fourier transform yields the processed time-domain signal yc, which contains only the signal and its reflection; the mismatch amplitude and phase parameters are estimated based on the signal yc. and .

[0048] ; Based on the yc signal, separate Two paths, where real is the real part of the complexed signal and imag is the imaginary part of the complexed signal:

[0049] Calculate the average power of the I-channel and Q-channel digital signals. and mean is used to calculate the average.

[0050] Then the estimated magnitude mismatch :

[0051] Simultaneously, calculate the cross-correlation function of the I and Q paths. :

[0052] And combine the autocorrelation function to estimate the phase error: .

[0053] 2. Pre-calibration execution: Construct the predistortion compensation matrix M: ; After applying the predistortion compensation matrix M, all I and Q sample pairs to be transmitted (pipeline service digital baseband complex signals) will pass through a matrix multiplier before being sent to the DAC, and be multiplied with matrix M to achieve image suppression.

[0054] 3. Adaptive Update: An internal counter can be set in the system to automatically trigger a new parameter estimation and update the predistortion compensation matrix M after processing N data packets (e.g., N=1000).

[0055] Furthermore, it can calculate the image suppression ratio in real time. For signal power, This is the mirror power. If the IRR falls below a preset threshold (e.g., 30dB), a re-estimation and update is immediately triggered to ensure that the mirror suppression effect is always better than the design requirements.

[0056] The digital array multi-channel adaptive monitoring and parameter update can be set to time-division processing.

[0057] 4. Simulation effect: Simulations can be performed using MATLAB, such as... Figure 5As shown, based on the above steps, a 1.92MHz frequency signal and a -1.92MHz image are extracted from the service signal to estimate the image distortion parameters and construct a pre-distortion compensation matrix. To demonstrate the effectiveness of this scheme in suppressing image distortion within the frequency band, other frequencies are selected as test signals. Here, the simulation selects a 4.32MHz frequency point. After pre-distortion compensation, its image distortion suppression is optimized from approximately 14dB to 60dB.

[0058] The real-time image suppression method for digital array transmission channels provided by this invention has the following significant advantages: 1. Real-time online calibration: Calibration signals can be injected without interrupting services, and calibration can be completed using the service signals themselves, effectively achieving real-time continuous image suppression.

[0059] 2. Strong adaptability: It can track and compensate for time-varying factors such as temperature and aging. Parameter drift is mitigated to maintain long-term stable high performance.

[0060] 3. High precision: Parameter estimation and compensation are performed using digital signal processing algorithms, resulting in high precision.

[0061] 4. Easy to integrate: The algorithm is mainly implemented in the digital domain (such as FPGA or DSP), making it easy to upgrade or integrate into existing digital array systems.

[0062] The real-time image suppression device for digital array transmission channels provided by the present invention is described below. The real-time image suppression device for digital array transmission channels described below can be referred to in correspondence with the real-time image suppression method for digital array transmission channels described above.

[0063] See Figure 3 The present invention provides a real-time image suppression device for a digital array transmission channel, comprising a digital baseband unit, a digital array antenna, and a main control unit. The digital array antenna includes a digital-to-analog converter front-end, an I / Q modulator, a power amplifier, and an antenna. The main control unit includes a receiver and a compensation module. A coupler and an RF feedback line are provided between the antenna of the digital array antenna and the receiver of the main control unit. The digital baseband unit is used to generate the pipelined digital baseband complex signal, the digital array antenna is used to receive, process and transmit the pipelined digital baseband complex signal, and the main control unit is used to execute the steps of the real-time image suppression method for the digital array transmission channel described above, so as to perform real-time image suppression on the pipelined digital baseband complex signal received by the digital array antenna.

[0064] The present invention provides a schematic diagram of the physical structure of an electronic device, which may include: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus. The processor can call logical instructions in the memory to execute the steps of the real-time image suppression method for the digital array transmit channel described above.

[0065] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0066] On the other hand, the present invention also provides a computer program product, the computer program product including a computer program, the computer program being stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer is able to perform the steps of the real-time image suppression method for the digital array transmission channel described in any of the above claims.

[0067] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the real-time image suppression method for the digital array transmit channel as described in any of the preceding claims.

[0068] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0069] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for real-time mirror rejection in a digital array transmit channel, comprising: include: The pipelined digital baseband complex signal is received from the digital baseband unit through the digital array transmit channel, and a feedback signal is extracted at the antenna of the digital array transmit channel. The pipelined digital baseband complex signal is preset to a frequency point where no signal is transmitted, and the feedback signal is the signal with image interference after the pipelined digital baseband complex signal passes through the I / Q modulator of the digital array transmit channel. Estimate the compensation parameters based on the feedback signals; Based on the compensation parameters, the predistortion compensation matrix is ​​constructed in real time; The pre-distortion compensation matrix is ​​used to pre-compensate the new pipelined service digital baseband complex signal received from the digital baseband unit by the digital array transmit channel, so as to preemptively offset the distortion that the I / Q modulator of the digital array transmit channel will introduce into the new pipelined service digital baseband complex signal, and realize real-time image suppression.

2. The real-time image suppression method for a digital array transmission channel according to claim 1, characterized in that, include: The output signal obtained by the I / Q modulator of the digital baseband complex signal of the pipeline operation is modeled to obtain the compensation parameters to be estimated. The ideal streaming digital baseband complex signal is a discrete digital signal, denoted as . ,satisfy In the formula, n is the discrete sampling number. express The in-phase component, i.e., the real part, express The orthogonal components, i.e., the imaginary part; The discrete digital signal After digital-to-analog conversion, a continuous-time domain analog in-phase signal is obtained. Orthogonal signals from analog And input to the I / Q modulator; The output signal obtained by the I / Q modulator from the digital baseband complex signal of the pipelined service is modeled as follows: ， In the formula, This represents the output signal obtained by passing an ideal streaming digital baseband complex signal through a non-ideal I / Q modulator. Indicates the amplitude mismatch factor. Indicates the phase error angle. Indicates the time independent variable of the signal flow; The compensation parameters to be estimated include the amplitude mismatch factor. and phase error angle .

3. The real-time image suppression method for a digital array transmission channel according to claim 2, characterized in that, The process of receiving pipelined digital baseband complex signals from digital baseband units via a digital array transmit channel and extracting feedback signals at the antenna of the digital array transmit channel includes: A frequency point is selected in the in-band spectrum of the pipelined digital baseband complex signal and the signal at that frequency point is set to zero. When the pipelined digital baseband complex signal with the signal at that frequency point set to zero passes through the I / Q modulator, its corresponding feedback signal is taken out at the antenna of the digital array transmission channel. This feedback signal is the signal of image interference that exists after the pipelined digital baseband complex signal passes through the I / Q modulator of the digital array transmission channel.

4. The real-time image suppression method for a digital array transmission channel according to claim 3, characterized in that, The step of estimating compensation parameters based on feedback signals includes: The amplitude mismatch factor is estimated based on the relative power of the main signal frequency and the mirror frequency in the feedback signal, as well as the phase relationship between the main signal frequency and the mirror frequency. and phase error angle .

5. The real-time image suppression method for a digital array transmission channel according to claim 4, characterized in that, The pre-compensation of the new pipelined service digital baseband complex signal received from the digital baseband unit by the digital array transmit channel using a pre-distortion compensation matrix includes: Before the new digital baseband complex signal undergoes digital-to-analog conversion, a pre-compensation expression is used to pre-compensate the new pipelined service digital baseband complex signal received from the digital baseband unit by the digital array transmit channel using a pre-distortion compensation matrix. The pre-compensation expression is as follows: ， In the formula, This represents the signal after pre-compensation of the new pipelined digital baseband complex signal received from the digital baseband unit by the digital array transmit channel using a pre-distortion compensation matrix. , These represent real-time digital baseband complex signals. The real and imaginary parts, with the superscript T indicating transpose. This represents the predistortion compensation matrix.

6. The real-time image suppression method for a digital array transmit channel according to any one of claims 1-5, characterized in that, Also includes: The digital baseband complex signal received by the digital array transmission channel and the radio frequency signal transmitted after image suppression are acquired. The image rejection ratio is obtained based on the digital baseband complex signal received by the digital array transmission channel and the radio frequency signal transmitted after image rejection. The image suppression ratio is used as a condition to set whether to re-estimate the compensation parameters, thereby achieving adaptive optimization of the predistortion compensation matrix.

7. The real-time image suppression method for a digital array transmit channel according to any one of claims 1-5, characterized in that, Also includes: Set the time period for re-estimating compensation parameters to update the predistortion compensation matrix periodically.

8. A real-time image suppression device for a digital array transmission channel, characterized in that, Includes digital baseband unit, digital array antenna, and main control unit. The digital array antenna includes a digital-to-analog converter front-end, an I / Q modulator, a power amplifier, and an antenna. The main control unit includes a receiver and a compensation module. A coupler and an RF feedback line are provided between the antenna of the digital array antenna and the receiver of the main control unit. The digital baseband unit is used to generate the pipelined digital baseband complex signal, the digital array antenna is used to receive, process and transmit the pipelined digital baseband complex signal, and the main control unit is used to execute the steps of the real-time image suppression method for the digital array transmission channel according to any one of claims 1-7, so as to perform real-time image suppression on the pipelined digital baseband complex signal received by the digital array antenna.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the real-time image suppression method for digital array transmission channels as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the real-time image suppression method for digital array transmission channels as described in any one of claims 1 to 7.

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