Signal calibration method, system, and storage medium

Abstract

Embodiments of the present application provide a signal calibration method and system and a storage medium, wherein the method comprises: transmitting a first calibration signal and a second calibration signal to a receiving end by a transmitting end, wherein the first calibration signal comprises a first direct current component added according to a first direct current offset value, the second calibration signal comprises a second direct current component added according to a second direct current offset value, and the first direct current offset value and the second direct current offset value are different; obtaining a direct current compensation value, wherein the direct current compensation value is determined according to a first received signal and a second received signal received by the receiving end, the first received signal corresponds to the first calibration signal, and the second received signal corresponds to the second calibration signal; and performing signal compensation on a transmitting signal of the transmitting end according to the direct current compensation value. Through the present application, the technical problem of low calibration accuracy in the related art signal calibration method is solved.

Description

Technical Field

[0001] This application relates to the field of signal processing, and more specifically, to a signal calibration method, system, and storage medium. Background Technology

[0002] When the signal is transmitted, the digital baseband signal is converted into an analog signal by a digital-to-analog converter. Its DC component will pass through a non-ideal module in the analog front-end link, causing the DC component observed at the air interface to have a gain. This affects the subsequent processing at the receiving end. The DC component observed at the receiving end will be a spurious component, which will seriously affect the demodulation performance under high-order modulation. In addition, this DC component will also affect the calibration results when performing high-level calibration of the transmit gain.

[0003] It is evident that the signal calibration methods in related technologies suffer from low calibration accuracy. Summary of the Invention

[0004] This application provides a signal calibration method, system, and storage medium to at least solve the technical problem of low calibration accuracy in signal calibration methods.

[0005] According to one aspect of the embodiments of this application, a signal calibration method is provided, comprising: transmitting a first calibration signal and a second calibration signal from a transmitting end to a receiving end, wherein the first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value, wherein the first DC offset value and the second DC offset value are different; obtaining a DC compensation value, wherein the DC compensation value is determined based on a first received signal and a second received signal received by the receiving end, wherein the first received signal corresponds to the first calibration signal, and the second received signal corresponds to the second calibration signal; and performing signal compensation on the transmitted signal of the transmitting end according to the DC compensation value.

[0006] According to another aspect of the embodiments of this application, a signal calibration method is also provided, comprising: acquiring a first received signal and a second received signal, wherein the first received signal is a received signal received by a receiving end corresponding to a first calibration signal sent by a transmitting end, and the second received signal is a received signal received by the receiving end corresponding to a second calibration signal sent by the transmitting end, the first calibration signal including a first DC component added according to a first DC offset value, and the second calibration signal including a second DC component added according to a second DC offset value, wherein the first DC offset value and the second DC offset value are different; determining a DC compensation value based on the first received signal and the second received signal received by the receiving end; and sending the DC compensation value to the transmitting end to compensate the transmitted signal of the transmitting end.

[0007] According to another aspect of the embodiments of this application, a signal calibration system is also provided, including: a transmitter, a receiver, and a control terminal, wherein the control terminal is connected to the transmitter and the receiver respectively; wherein the transmitter is used to transmit a first calibration signal and a second calibration signal, wherein the first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value, wherein the first DC offset value and the second DC offset value are different; the control terminal is used to determine a DC compensation value based on the first received signal and the second received signal received by the receiver, wherein the first received signal corresponds to the first calibration signal, and the second received signal corresponds to the second calibration signal; the receiver is used to acquire the first received signal and the second received signal, and send the DC compensation value to the transmitter to perform signal compensation on the transmitted signal of the transmitter.

[0008] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, wherein a computer program is stored therein, wherein the computer program is configured to perform the steps in any of the above method embodiments when executed by a processor.

[0009] According to another aspect of the embodiments of this application, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform the steps in any of the method embodiments described above.

[0010] According to another aspect of the embodiments of this application, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to perform the steps of any of the above method embodiments through the computer program.

[0011] This application involves transmitting a first calibration signal and a second calibration signal from a transmitter to a receiver. The first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value. The first and second DC offset values ​​are different. A DC compensation value is obtained, which is determined based on the first and second received signals received by the receiver. The first received signal corresponds to the first calibration signal, and the second received signal corresponds to the second calibration signal. The transmitted signal from the transmitter is compensated based on the DC compensation value. Since modeling is performed based on the calibration signal, DC component distortion caused by non-ideal simulation modules can be separated and compensated. Therefore, this solves the technical problem of low calibration accuracy in related signal calibration methods, thereby improving the accuracy of signal calibration. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating an application scenario of a signal calibration method according to an embodiment of this application;

[0013] Figure 2 This is a flowchart illustrating an optional signal calibration method according to an embodiment of this application;

[0014] Figure 3 This is a schematic diagram of an optional signal calibration method according to an embodiment of this application;

[0015] Figure 4 This is a schematic diagram of another optional signal calibration method according to an embodiment of this application;

[0016] Figure 5 This is a schematic diagram of another optional signal calibration method according to an embodiment of this application;

[0017] Figure 6 This is a flowchart illustrating another optional signal calibration method according to an embodiment of this application;

[0018] Figure 7 This is a structural block diagram of an optional signal calibration system according to an embodiment of this application;

[0019] Figure 8 This is a computer system architecture block diagram of an optional electronic device according to an embodiment of this application. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] According to one aspect of the embodiments of this application, a signal calibration method is provided. Optionally, in this embodiment, the above-described signal calibration method may be applied to, but is not limited to, [examples of applications such as...]. Figure 1 The hardware environment shown includes a transmitter 102 and a receiver 104. The signal calibration method of this embodiment can be performed by the transmitter 102, by the receiver 104, or by both the transmitter 102 and the receiver 104.

[0023] Taking the signal calibration method in this embodiment performed by the transmitter 102 as an example, Figure 2 This is a flowchart illustrating an optional signal calibration method according to an embodiment of this application, as shown below. Figure 2 As shown, the process of this method may include the following steps:

[0024] Step S202: Transmit a first calibration signal and a second calibration signal to the receiver through the transmitter. The first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value. The first DC offset value and the second DC offset value are different.

[0025] Step S204: Obtain the DC compensation value, wherein the DC compensation value is determined based on the first received signal and the second received signal received by the receiving end, the first received signal corresponds to the first calibration signal, and the second received signal corresponds to the second calibration signal; Step S206: Perform signal compensation on the transmitting signal of the transmitting end based on the DC compensation value.

[0026] The signal calibration method in this embodiment can be applied to the field of signal processing, specifically to scenarios where transmitted signals are compensated and calibrated at the signal transmitting end.

[0027] For the transmitting end of the signal, after the digital baseband signal is converted into an analog signal by a digital-to-analog converter (DAC), its DC component is retained as a constant bias component of the baseband signal. This DC component may pass through non-ideal analog modules such as a low-pass filter (LPF), mixer, and digital power amplifier (DPA) in the analog front-end link. Due to physical limitations such as process deviations, temperature drift, device nonlinearity, and local oscillator leakage, these modules will produce nonlinear gain modulation and phase distortion on the DC component. For example, due to the incomplete isolation of the local oscillator signal, the mixer may produce local oscillator leakage, which will convert the baseband DC frequency. The non-flat amplitude-frequency characteristics of the LPF and the gain compression effect of the DPA may introduce amplitude distortion, so that the DC component radiated to the air interface by the antenna is a complex offset modulated by the link gain. Its amplitude and phase are no longer equal to the original DC value at the DAC output.

[0028] The DC component after link distortion can be represented at the receiver as a spur in the intermediate frequency or baseband spectrum. Its energy can be concentrated at 0Hz or a non-zero frequency point determined by the local oscillator frequency offset. This spur may be superimposed on the demodulated sample of the useful signal, which will affect the subsequent processing at the receiver.

[0029] like Figure 3 As shown, without any digital compensation applied, the transmitted signal, after transmission, exhibits a significant spectral peak in the intermediate frequency domain at the receiver due to inherent offset of the analog circuitry and local oscillator leakage in the transmission link. This peak, after mixing and amplification, is mapped to the receiver. The peak is in complex form and appears as a discrete component stronger than the background noise in the spectrum, indicating that the DC offset at the transmitter is not suppressed and its energy is concentrated in the non-zero intermediate frequency, interfering with the receiver's demodulation of the effective signal.

[0030] Furthermore, during high-level calibration of the transmit gain in the transmit link, the output power of the power amplifier exhibits a non-linear mapping relationship with the input baseband gain. The calibration algorithm typically relies on loop power measurements fed back from the receiver to fit the gain curve. If the residual DC component in the transmit link is not compensated, its non-zero DC response at the loop detection point may be misidentified as a useful signal power component, leading to a deviation in the gain calibration model. This DC component will also affect the calibration results.

[0031] It is evident that the signal calibration methods in related technologies suffer from low calibration accuracy.

[0032] To at least partially solve the aforementioned technical problems, in this embodiment, a first calibration signal and a second calibration signal are transmitted from the transmitting end to the receiving end. The first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value. The first DC offset value and the second DC offset value are different. A DC compensation value is obtained, which is determined based on the first and second received signals received by the receiving end. The first received signal corresponds to the first calibration signal, and the second received signal corresponds to the second calibration signal. The transmitted signal from the transmitting end is compensated based on the DC compensation value. Since modeling is performed based on the calibration signal, the DC component distortion caused by the non-ideal simulation module can be separated and compensated. Therefore, the technical problem of low calibration accuracy in related signal calibration methods can be solved, thereby improving the accuracy of signal calibration.

[0033] In this embodiment, to eliminate the above-mentioned effects, a DC compensation value can be confirmed to compensate for the DC component at the transmitting end, thereby eliminating subsequent offset.

[0034] Optionally, two sets of known and distinct DC bias values ​​can be configured in the baseband digital domain of the transmitter, which can be used as calibration excitation signals and transmitted sequentially through the transmission link.

[0035] Optionally, a first calibration signal and a second calibration signal can be transmitted from the transmitter to the receiver. The first calibration signal superimposed a first DC component d0, determined by a preset first DC offset value, onto the baseband digital signal. The second calibration signal superimposed a second DC component d1, determined by a preset second DC offset value, onto the baseband digital signal. The first and second DC offset values ​​are numerically distinct and both are non-zero. Here, the first and second DC offset values ​​can be generated by the transmitter's digital baseband processor according to calibration control instructions and directly injected into the input of the DAC via a digital adder, embedding them into the baseband signal before digital-to-analog conversion. The amplitude difference between the two DC components can produce a distinguishable response difference at the receiver, and their value range can be limited to the linear operating range of the transmit link to avoid additional errors introduced by DPA saturation or LPF nonlinear distortion due to overload.

[0036] Optionally, after the first and second calibration signals are converted into analog signals by the digital-to-analog converter at the transmitting end, they can sequentially pass through analog front-end modules such as a low-pass filter (LPF), a mixer, and a power amplifier (DPA) before being radiated to the air interface. Due to non-ideal characteristics such as process deviations, local oscillator leakage, non-flat amplitude-frequency characteristics, and gain compression in the above modules, the original DC component is modulated into a complex offset affected by both link gain and phase response during link propagation. Therefore, the first and second calibration signals are received as the first and second received signals at the receiving end, respectively. In the frequency domain, they exhibit two complex responses with different amplitudes and phases, corresponding to the link output responses under different input DC excitations.

[0037] Optionally, the receiving end can receive the above signal amplified by a series of circuits, and finally observe the first and second received signals at the air interface, wherein the first received signal corresponds to the first calibration signal, and the second received signal corresponds to the second calibration signal.

[0038] Optionally, the local oscillator (LO) frequency can have a fixed frequency offset Δf from the transmitter's local oscillator frequency, so that the transmitter's baseband DC component, after down-conversion at the receiver, is mapped to a non-zero frequency point -Δf in the intermediate frequency or baseband processing channel, thereby achieving frequency domain separation from the receiver's own DC offset. The receiver can perform frequency domain transformations on the first and second received signals respectively to obtain two complex response values, denoted as d0. tx0 With d tx1Here, the output response of the first received signal and the output response of the second received signal can be a linear combination of the input DC offset and the inherent distortion of the link. Since the propagation path and distortion mechanism in the transmission link are completely consistent except for the different settings of the first and second DC offset values, the different output responses are only due to the different input excitations. The unknown parameters can be eliminated by calculation based on the complex response values ​​of the first and second received signals obtained by the receiver, so as to determine the link gain and then the DC compensation value.

[0039] Optionally, after obtaining the DC compensation value, the transmitter can add the compensation value to the DC component of the digital baseband signal in subsequent normal operating modes, that is, superimpose the DC compensation value on the baseband signal at the input of the digital-to-analog converter.

[0040] Optionally, the DC compensation value can be pre-stored or dynamically updated as needed at different transmit gain levels.

[0041] After compensation, the analog signal output from the transmitter is processed by non-ideal modules such as LPF, mixer, and power amplifier. Its output DC component can be effectively suppressed to the theoretical zero value, thereby eliminating the spur caused by DC leakage in the air interface spectrum, significantly improving the demodulation performance of high-order modulation signals, and ensuring that the transmit gain calibration process is not affected by DC interference.

[0042] Through the embodiments of this application, a first calibration signal and a second calibration signal are transmitted from the transmitting end to the receiving end. The first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value. The first DC offset value and the second DC offset value are different. A DC compensation value is obtained, wherein the DC compensation value is determined based on the first received signal and the second received signal received by the receiving end. The first received signal corresponds to the first calibration signal, and the second received signal corresponds to the second calibration signal. The transmitted signal of the transmitting end is compensated according to the DC compensation value, which solves the technical problem of low calibration accuracy in related signal calibration methods and achieves the effect of improving the accuracy of signal calibration.

[0043] In an exemplary embodiment, both the transmitting end and the receiving end are equipped with local oscillators, wherein the operating frequency of the local oscillator of the transmitting end is a first frequency, and the operating frequency of the local oscillator of the receiving end is a second frequency, the second frequency being higher than the first frequency, and the first frequency and the second frequency differing from each other by a preset frequency offset.

[0044] Optionally, both the transmitter and receiver integrate a local oscillator (LO) to perform up-conversion and down-conversion processing of the baseband signal.

[0045] Optionally, the local oscillator at the transmitting end can be configured to operate at a first frequency, which is used to modulate the digital baseband signal to the radio frequency transmission band; the local oscillator at the receiving end can be configured to operate at a second frequency, which is used to down-convert the received radio frequency signal to recover the baseband signal. The second frequency can be higher than the first frequency, and the difference between the two is a preset fixed frequency offset Δf, i.e., the LO frequency of TX can be configured as follows: The LO frequency of RX is .

[0046] Optionally, the aforementioned frequency offset can be a non-zero offset, the value of which can be optimized based on the system sampling rate, Fourier transform analysis window length, and spectral resolution requirements to ensure that the spectral component corresponding to the calibration signal accurately falls at Δf when the received signal is analyzed and processed at the receiving end. This frequency configuration causes the DC offset component output from the transmitting end to form a discrete spectral component in the intermediate frequency domain at the receiving end, which is separate from the receiver's own DC offset spectrum, after mixing, thereby achieving orthogonal isolation between the transmitting end DC and the receiving end DC in the frequency domain.

[0047] Optionally, when the receiver performs frequency domain transformation on the first received signal and the second received signal respectively, since the DC at the receiver is at zero frequency and the DC at the transmitter is moved to Δf after mixing, the two do not overlap in the frequency domain. Therefore, when the receiver extracts the frequency domain transformation amplitude at Δf, it does not need to estimate, model or compensate the RX DC, which effectively simplifies the complexity of the calibration algorithm.

[0048] Optionally, the aforementioned preset frequency offset can be kept constant during the calibration process, without changing with the transmit gain level or ambient temperature, ensuring that the two calibration signals are received under the same frequency offset conditions.

[0049] In this embodiment, by setting the frequency offset of the local oscillator, it is possible to eliminate the need for estimation, modeling, or compensation of the RX DC, effectively simplifying the complexity of the calibration algorithm.

[0050] In one exemplary embodiment, transmitting a first calibration signal and a second calibration signal from the transmitting end to the receiving end includes:

[0051] The transmitter first transmits a first calibration signal to the receiver for a specified duration, and then transmits a second calibration signal to the receiver for a specified duration. The product of the specified time and the preset frequency offset is an integer multiple of the sampling rate of the receiver.

[0052] In this embodiment, the transmitter can first continuously output a first calibration signal for a specified duration M in a preset calibration mode. This signal is generated by a digital baseband module, and its DC component is determined based on a first DC offset value d0. After digital-to-analog conversion, it is processed by an analog front-end link (including a low-pass filter, mixer, and power amplifier) ​​and finally sent to the receiver. Subsequently, after completing the transmission of the first calibration signal, the transmitter can output a second calibration signal, also continuously outputting the second calibration signal for the same specified duration M. Its DC component is determined based on a second DC offset value d1.

[0053] Optionally, to ensure the accuracy of the receiver's frequency domain analysis of the loopback signal, the product of the specified time and the preset frequency offset can be an integer multiple of the receiver's sampling rate, thus guaranteeing accuracy. The integer value ensures that when the receiver performs frequency domain transformation (e.g., discrete Fourier transform) on the received signal, the frequency remains consistent. The sinusoidal component is formed with a complete integer cycle sampling, thereby eliminating the spectrum leakage effect. This allows the amplitude of the target frequency point to accurately reflect the real output response of the transmitter DC after transmission through the analog link, without introducing sidelobe interference or energy dissipation caused by non-integer cycle truncation.

[0054] Furthermore, the value of the specified duration M is determined by the system sampling rate. With preset frequency offset It was jointly decided that a sufficient time interval could be reserved between the transmission of the two calibration signals to ensure that the two measurements were completed within their respective independent time domain windows without interfering with each other.

[0055] In this embodiment, by setting the product of the specified time and the preset frequency offset to be an integer multiple of the sampling rate of the receiving end, the response values ​​of the first received signal and the second received signal obtained by the receiving end at the frequency offset point can have highly consistent sampling conditions, providing reliable and aliased observation data. This design achieves high-precision modeling and compensation for the non-ideal DC effect of the transmitting end without increasing additional hardware overhead, significantly improving calibration accuracy and system stability.

[0056] In one exemplary embodiment, after transmitting the first calibration signal and the second calibration signal from the transmitter to the receiver, the method further includes:

[0057] The first received signal is down-converted and mixed, and an N-point discrete Fourier transform is performed on the first received signal at a specified non-zero intermediate frequency point to obtain the first received response value.

[0058] The second received signal is down-converted and mixed, and an N-point discrete Fourier transform is performed on the second received signal at a specified non-zero intermediate frequency point to obtain the second received response value.

[0059] The DC compensation value is determined based on the first DC offset value, the second DC offset value, the first receive response value, and the second receive response value.

[0060] In this embodiment, the receiving end can perform down-conversion processing on the received signal, using a second frequency signal generated by a local oscillator to mix the first and second received signals respectively, thereby extracting the spectrum of the DC offset component from the transmitting end. This down-conversion process, while maintaining the stability of the receiving link gain and filtering characteristics, ensures that both the first and second received signals are mapped to the same specified non-zero intermediate frequency point in the frequency domain.

[0061] Optionally, the specified non-zero intermediate frequency point can be determined by a preset frequency offset between the local oscillators of the transmitting and receiving ends. The value is determined and is non-zero, in order to achieve orthogonal isolation from the receiver's own DC offset component in the frequency domain.

[0062] Optionally, after down-conversion, the receiving end can perform a Discrete Fourier Transform (DFT) of length N on the first and second received signals at a specified non-zero intermediate frequency point. That is, the DFT operation is performed at a fixed frequency point. The process is performed at the transmitter to extract the spectral response corresponding to the DC component injected at the transmitter.

[0063] Similar to the previous embodiments, the number of DFT points N can be matched with the sampling duration M and the sampling rate to meet the whole-cycle sampling condition, thereby ensuring that the spectral energy is concentrated at the specified non-zero intermediate frequency point and suppressing interference introduced by spectral leakage and window effect.

[0064] Through the above processing, the first received response value and the second received response value can be obtained respectively. The first received response value and the second received response value can respectively indicate the complex domain response amplitude observed at the receiver after the transmitter is modulated by the non-ideal characteristics of the simulated link (including low-pass filter gain, mixing leakage, power amplifier response, etc.) under the conditions of injecting the first DC offset value and the second DC offset value.

[0065] Optionally, based on the first DC offset value, the second DC offset value, the first received response value, and the second received response value, parameter inversion can be performed. By observing the response under two different inputs, a set of models containing unknown parameters can be constructed and the common system error term can be eliminated to determine the equivalent DC calibration parameters required for compensation, i.e., the DC compensation value.

[0066] In this embodiment, frequency domain isolation can achieve natural decoupling between the transmitter and receiver, avoiding the complex receiver suppression mechanism in traditional schemes. By using the responses of two known inputs to build a model, complex algorithms such as matrix inversion and phase estimation can be eliminated, significantly reducing computational complexity and resource consumption.

[0067] In one exemplary embodiment, both the first received response value and the second received response value are in complex form;

[0068] The DC compensation value is determined based on the first DC offset value, the second DC offset value, the first received response value, and the second received response value, including:

[0069] A first intermediate value is determined based on a first difference between a first DC offset value and a second DC offset value and a second difference between a first received response value and a second received response value. The first intermediate value is the ratio of the first difference to the second difference.

[0070] The DC compensation value is obtained by subtracting the product of the first received response value and the first intermediate value from the first DC offset value.

[0071] If we assume that the value of dc is Where a is the DC component of the in-phase path and b is the DC component of the quadrature (Q) path, this complex form represents that in the modulation structure, the DC offset of the digital baseband signal exists simultaneously in both the in-phase and quadrature branches, and after passing through the mixer, it can be expressed as formula (1):

[0072] (1)

[0073] in t and t represent the amplitude and phase inconsistency of LO, respectively. After obtaining the expression for the Mixer, it is amplified through a series of circuits, and finally, the DC observed at the air interface can be gY.

[0074] As shown in formula (1), the value obtained after DC is processed through non-ideal means is not a simple multiple relationship. Correspondingly, when performing DC calibration at the transmitter, we can assume that the DC caused by the LPF and analog circuit is m, the DC caused by the local oscillator is n, and the gain of the low-pass filter LPF is... The gain of the power amplifier DPA is Therefore, the DC at the transmitting end observed in the loop can be expressed as shown in Equation (2), that is, the DC response finally observed at the transmitting end is the weighted sum of the compensated input, inherent offset, and leakage component after being coupled by the link gain, and all terms are affected by the analog gain. and Unified magnification:

[0075] (2)

[0076] The calibration objective of this embodiment can be to find a suitable compensation value. This results in the DC response of the transmitter at the air interface or loop observation point being zero, as shown in formula (3):

[0077] (3)

[0078] Based on this, it can be confirmed that the DC compensation value should be as shown in formula (4):

[0079] (4)

[0080] Similar to the previous embodiments, a first calibration signal and a second calibration signal can be transmitted from the transmitter to the receiver. The first calibration signal includes a first DC component added according to a first DC offset value d0, and the second calibration signal includes a second DC component added according to a second DC offset value d1. The LO frequency of TX is configured as follows: The LO frequency of RX is Since there is an offset between RX LO and TX LO, the DC component injected by the transmitter is mapped to a specified non-zero intermediate frequency after mixing, while the DC of the receiver itself is completely suppressed due to frequency domain orthogonality, so there is no need to consider RX DC interference.

[0081] Optionally, the signal is mixed by a mixer and then returned to the receiver RX. When the signal enters the receiver RX, the frequency of RX is adjusted. By performing a DFT calculation of length N points at point d, the first received response value d can be obtained. tx0 Second received response value d tx1 As shown in formulas (5) and (6):

[0082] (5)

[0083] (6)

[0084] For the duration of sending each known DC, it can be guaranteed that If the integer is an integer, then formula (6) can be simplified to formula (7):

[0085] (7)

[0086] Optionally, based on the first received response value d tx0 Second received response value d tx1It can be determined that the relationship shown in formula (8) is the ratio of the difference between two observed responses to the difference between two known inputs, completely eliminating the unknowns m and n. This ratio only reflects the gain response of the transmit link to the input change and does not depend on any fixed offset term, thus having extremely strong robustness.

[0087] (8)

[0088] Based on the above formula, we can substitute it into formula (5) to obtain formula (9):

[0089] (9)

[0090] In order to make the DC response of the transmitter at the air interface or loop observation point zero, the DC compensation value can be determined. Based on the results of formula (9) and formula (4), the DC compensation value should be as shown in formula (10):

[0091] = (10)

[0092] In this embodiment, the known input DC offset value can be used as a reference, minus the ratio of the observed response dtx0 to the system gain. The combined calculated equivalent predicted response is the DC compensation value required to offset all non-ideal effects of the simulated link.

[0093] In this embodiment, by constructing an observation model based on dual-input differential and combining it with non-zero intermediate frequency DFT detection, the compensation value can be directly calculated directly through only two input-output observations without separately estimating the unknown gain parameters. This avoids complex parameter identification and iterative optimization, suppresses the influence of local oscillator leakage, and is free from DC offset interference at the receiver, thus improving the efficiency and accuracy of the estimation.

[0094] In one exemplary embodiment, signal compensation is performed on the transmitted signal at the transmitting end based on a DC compensation value, including:

[0095] The DC compensation value is superimposed on the original baseband signal of the transmitted signal, where the DC compensation value is negative.

[0096] Similar to the previous embodiments, a DC compensation value can be determined. The DC compensation value can be in complex form and can contain two components: in-phase and quadrature, which correspond to two independent branches in the baseband modulation structure, respectively.

[0097] In this embodiment, the DC compensation value can be superimposed on the original baseband signal of the transmitted signal. This operation is performed in the digital domain, before the digital-to-analog converter, and belongs to the baseband pre-compensation mechanism.

[0098] Optionally, in the transmit signal processing path, the original baseband signal can be a sequence of digital symbols to be modulated, which, in the uncompensated state, may only contain zero-mean symbols introduced by the digital signal processing module and necessary pilot or training sequences. To achieve DC cancellation, the DC compensation value can be superimposed on each sampling point of the original baseband signal in the form of a constant DC component.

[0099] Optionally, the DC compensation value can be negative. A compensation current or voltage equivalent can be injected at the transmitter in the opposite direction to the inherent DC offset of the link, ensuring that the analog signal after DAC conversion already contains a reverse correction component before entering the analog front end. This mechanism, by canceling non-ideal offsets in the link, suppresses the DC component in the final RF signal after mixing, amplification, and radiation to below the receiver's detection threshold.

[0100] like Figure 4 The image shows the spectral response at a specified non-zero intermediate frequency point after injecting the aforementioned DC compensation value into the baseband signal at the transmitting end. At this point, the original strong spectral lines have significantly attenuated, with their amplitude decreasing to near the system noise floor. The compensation injected at the transmitting end has successfully canceled the DC response. There are no significant discrete spectral lines in the spectrum, and the DC offset has been effectively eliminated.

[0101] In this embodiment, by compensating the original baseband signal with DC compensation value, compensation mismatch caused by nonlinearity and temperature drift in the analog path can be avoided, thus achieving high-precision transmit DC calibration.

[0102] In one exemplary embodiment, the signal transmission path between the transmitter and receiver is an on-chip loopback path.

[0103] Optionally, the signal transmission path between the transmitter and receiver can be an on-chip loopback path, that is, the signal transmission path between the transmitter and receiver can be a physical signal path integrated within the same component, so that the radio frequency signal output from the transmit link can be directly coupled to the input of the receive link without passing through an external antenna or air interface, so as to realize the self-test and calibration of the transmitter performance. Since the transmission characteristics of the loopback path are highly consistent with the actual air interface path in terms of baseband DC response, its measurement results can be directly used to derive the DC offset model of the transmit link.

[0104] Optionally, the DC compensation value determined in the on-chip loopback path described above can also be applied to signal transmission in other scenarios. For example, it can be applied to real receiving scenarios with external components to extrapolate the calibration model.

[0105] like Figure 5 As shown, when the observation point is located on the path of the observation receiver, i.e., when it is observed through the internal receiving channel used for calibration feedback, the observed spectrum state is similar to... Figure 2The spectrum pattern is consistent, and the on-chip loopback path can accurately reproduce the DC leakage characteristics of the transmit link. Its observation results can be used as the input basis for the calibration algorithm.

[0106] Through this embodiment, by setting the on-chip loopback path, environmental interference or wear and tear can be avoided, ensuring the repeatability and accuracy of the calibration process.

[0107] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0108] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, 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 is stored in a storage medium (such as read-only memory (ROM) / random access memory (RAM), magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0109] According to another aspect of the embodiments of this application, a signal calibration method is also provided, which can be applied to a receiving end. Figure 6 This is a flowchart illustrating an optional signal calibration method according to an embodiment of this application, as shown below. Figure 6 As shown, the process of this method may include the following steps:

[0110] Step S602: Obtain a first received signal and a second received signal, wherein the first received signal is a received signal received by the receiving end that corresponds to the first calibration signal sent by the transmitting end, and the second received signal is a received signal received by the receiving end that corresponds to the second calibration signal sent by the transmitting end. The first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value. The first DC offset value and the second DC offset value are different.

[0111] Step S604: Determine the DC compensation value based on the first and second received signals received by the receiving end;

[0112] Step S606: Send the DC compensation value to the transmitter to compensate the transmitter's transmitted signal.

[0113] The receiving end described above can correspond to the sending end in the aforementioned embodiments, and will not be repeated hereafter.

[0114] The embodiments provided in this application obtain a first received signal and a second received signal. The first received signal is a received signal received by the receiving end that corresponds to a first calibration signal sent by the transmitting end, and the second received signal is a received signal received by the receiving end that corresponds to a second calibration signal sent by the transmitting end. The first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value. The first DC offset value and the second DC offset value are different. A DC compensation value is determined based on the first and second received signals received by the receiving end. The DC compensation value is sent to the transmitting end to compensate the transmitted signal of the transmitting end. This solves the technical problem of low calibration accuracy in related signal calibration methods and achieves the effect of improving the accuracy of signal calibration.

[0115] According to another aspect of the embodiments of this application, a signal calibration system is also provided, which can be used to implement the signal calibration method provided in the above embodiments, and will not be repeated hereafter. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0116] Figure 7 This is a structural block diagram of an optional signal calibration system according to an embodiment of this application, such as... Figure 7 As shown, the signal calibration system includes: a transmitter 702, a receiver 704, and a control terminal 706, with the control terminal 706 connected to both the transmitter 702 and the receiver 704; wherein,

[0117] Transmitter 702 is used to transmit a first calibration signal and a second calibration signal, wherein the first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value, wherein the first DC offset value and the second DC offset value are different;

[0118] The control terminal 706 is used to determine the DC compensation value based on the first received signal and the second received signal received by the receiving terminal. The first received signal corresponds to the first calibration signal, and the second received signal corresponds to the second calibration signal.

[0119] The receiver 704 is used to acquire the first received signal and the second received signal, and send the DC compensation value to the transmitter to compensate the transmitted signal of the transmitter.

[0120] It should be noted that the transmitting end 702 in this embodiment can be used to execute the above steps S202 to S206, the receiving end 704 in this embodiment can be used to execute the above steps S502 to S506, and the control end 706 in this embodiment can be used to execute the above step S504. The control end in this embodiment can be located in the transmitting end 702 or the receiving end 704, or it can be located in an external electronic device.

[0121] The embodiments provided in this application involve transmitting a first calibration signal and a second calibration signal from a transmitting end to a receiving end. The first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value. The first DC offset value and the second DC offset value are different. A DC compensation value is obtained, which is determined based on the first and second received signals received by the receiving end. The first received signal corresponds to the first calibration signal, and the second received signal corresponds to the second calibration signal. The transmitted signal from the transmitting end is compensated based on the DC compensation value, thus solving the technical problem of low calibration accuracy in related signal calibration methods and achieving the effect of improving the accuracy of signal calibration.

[0122] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0123] According to another aspect of the embodiments of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein the program executes the steps in any of the above method embodiments when it is run.

[0124] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as USB flash drives, ROMs, RAMs, portable hard drives, magnetic disks, or optical disks.

[0125] According to another aspect of the embodiments of this application, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor is configured to perform the steps of any of the method embodiments described above via the computer program. In an exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0126] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0127] According to another aspect of the embodiments of this application, a computer program product is also provided, comprising a computer program / instructions containing program code for performing the methods shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via a communication section 809, and / or installed from a removable medium 811. When the computer program is executed by a central processing unit 801, it performs various functions provided in the embodiments of this application. The sequence numbers of the embodiments of this application above are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0128] Figure 8 A schematic block diagram of a computer system architecture for implementing embodiments of the present application is shown. Figure 8 As shown, the computer system 800 includes a Central Processing Unit (CPU) 801, which can perform various appropriate actions and processes based on programs stored in ROM 802 or programs loaded into RAM 803 from storage section 808. Random access memory 803 also stores various programs and data required for system operation. The CPU 801, ROM 802, and RAM 803 are interconnected via bus 804. Input / output (I / O) interface 805 is also connected to bus 804.

[0129] The following components are connected to I / O interface 805: an input section 806 including a keyboard, mouse, etc.; an output section 807 including a cathode ray tube (CRT), liquid crystal display (LCD), and speakers, etc.; a storage section 808 including a hard disk, etc.; and a communication section 809 including a network interface card, such as a local area network card or modem, etc. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to I / O interface 805 as needed. Removable media 811, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 810 as needed so that computer programs read from them can be installed into storage section 808 as needed.

[0130] Specifically, according to embodiments of this application, the processes described in the various method flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 809, and / or installed from removable medium 811. When the computer program is executed by central processing unit 801, it performs various functions defined in the system of this application.

[0131] It should be noted that, Figure 8 The computer system 800 of the electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0132] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0133] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A signal calibration method, characterized in that, include: A first calibration signal and a second calibration signal are transmitted from the transmitter to the receiver. The first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value. The first DC offset value and the second DC offset value are different. Obtain a DC compensation value, wherein the DC compensation value is determined based on a first received signal and a second received signal received by the receiving end, the first received signal corresponding to the first calibration signal, and the second received signal corresponding to the second calibration signal; The transmitted signal of the transmitting end is compensated according to the DC compensation value.

2. The method according to claim 1, characterized in that, Both the transmitting end and the receiving end are equipped with local oscillators. The local oscillator of the transmitting end operates at a first frequency, and the local oscillator of the receiving end operates at a second frequency. The second frequency is higher than the first frequency, and the first frequency and the second frequency differ from each other by a preset frequency offset.

3. The method according to claim 2, characterized in that, The transmission of the first calibration signal and the second calibration signal from the transmitter to the receiver includes: The transmitter first transmits the first calibration signal to the receiver for a specified duration, and then transmits the second calibration signal to the receiver for the specified duration, wherein the product of the specified duration and the preset frequency offset is an integer multiple of the sampling rate of the receiver.

4. The method according to claim 2, characterized in that, After transmitting the first calibration signal and the second calibration signal from the transmitter to the receiver, the method further includes: The first received signal is down-converted and mixed, and an N-point discrete Fourier transform is performed on the first received signal at a specified non-zero intermediate frequency point to obtain the first received response value. The second received signal is down-converted and mixed, and an N-point discrete Fourier transform is performed on the second received signal at the specified non-zero intermediate frequency point to obtain the second received response value. The DC compensation value is determined based on the first DC offset value, the second DC offset value, the first received response value, and the second received response value.

5. The method according to claim 4, characterized in that, Both the first received response value and the second received response value are in complex form; Determining the DC compensation value based on the first DC offset value, the second DC offset value, the first received response value, and the second received response value includes: A first intermediate value is determined based on a first difference between the first DC offset value and the second DC offset value and a second difference between the first received response value and the second received response value, wherein the first intermediate value is the ratio of the first difference to the second difference. The DC compensation value is obtained by subtracting the product of the first received response value and the first intermediate value from the first DC offset value.

6. The method according to claim 1, characterized in that, The step of compensating the transmitted signal of the transmitting end according to the DC compensation value includes: The DC compensation value is superimposed on the original baseband signal of the transmitted signal, wherein the DC compensation value is negative.

7. The method according to any one of claims 1 to 6, characterized in that, The signal transmission path between the transmitter and the receiver is an on-chip loopback path.

8. A signal calibration method, characterized in that, include: Acquire a first received signal and a second received signal, wherein the first received signal is a received signal received by the receiving end that corresponds to a first calibration signal sent by the transmitting end, and the second received signal is a received signal received by the receiving end that corresponds to a second calibration signal sent by the transmitting end. The first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value. The first DC offset value and the second DC offset value are different. The DC compensation value is determined based on the first and second received signals received by the receiving end. The DC compensation value is sent to the transmitter to compensate the transmitter's transmitted signal.

9. A signal calibration system, characterized in that, include: The system includes a transmitter, a receiver, and a control terminal, with the control terminal connected to both the transmitter and the receiver. The transmitting end is used to transmit a first calibration signal and a second calibration signal, wherein the first calibration signal includes a first DC component added according to a first DC offset value, and the second calibration signal includes a second DC component added according to a second DC offset value, wherein the first DC offset value and the second DC offset value are different; The control terminal is used to determine a DC compensation value based on a first received signal and a second received signal received by the receiving terminal, wherein the first received signal corresponds to the first calibration signal and the second received signal corresponds to the second calibration signal. The receiving end is used to acquire the first received signal and the second received signal, and send the DC compensation value to the transmitting end to compensate the transmitted signal of the transmitting end.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method according to any one of claims 1 to 7, or the steps of the method according to claim 8.

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