A training sequence free receiver mirror compensation method and system

Abstract

This application provides a receiver image compensation method and system without a training sequence, relating to the field of wireless communication technology. After obtaining the intermediate frequency (IF) signal and its conjugate signal, the method calculates image coefficients based on the correlation between the IF signal and the conjugate signal, then synthesizes an image compensation matrix according to the image coefficients, and finally uses the image compensation matrix for image compensation. The method can analyze random spatial radiation signals received by the receiver in free space, utilizing the conjugate relationship between the image signal and the main signal, and obtaining the image compensation coefficients through the conjugate correlation of the IF signal. This method can analyze the image coefficients without a dedicated training sequence, reducing the complexity and hardware requirements of image compensation.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a receiver image compensation method and system without training sequences. Background Technology

[0002] The wireless signal receiving section of User Equipment (UE) can employ a zero-IF receiver. Also known as a direct-conversion receiver, a zero-IF receiver directly converts the received radio frequency signal into a baseband signal without any intermediate frequency (IF) processing. The baseband signal can include in-phase (I) and quadrature (Q) baseband signals. The I and Q signals are quadrature and work together to recover the signal's amplitude and phase. In a zero-IF receiver, the analog I and Q signal links from the mixer to the analog-to-digital converter (ADC) are called the IF IQ channels.

[0003] Because zero-IF receivers do not perform intermediate frequency (IF) processing, they cause IF IQ channel imbalance. This means that the I and Q links, which should be perfectly balanced, become unbalanced, exhibiting inconsistencies in amplitude and phase. This IF IQ channel imbalance introduces image interference; for example, interference signals located at negative frequencies may leak to positive frequencies, potentially affecting the signal-to-noise ratio (SNR) in severe cases.

[0004] To mitigate the image problem in receivers, a known signal needs to be coupled into the receiver front end. Then, the known signal and its mirror signal are extracted from the received intermediate frequency signal, and the image compensation coefficient is obtained through calculation. However, the above calculation process for the image compensation coefficient requires generating a known training sequence, extracting the known signal and its mirror signal components, and then using complex iterative calculations to obtain the compensation coefficient, increasing the complexity of image compensation and hardware requirements. Summary of the Invention

[0005] In view of this, embodiments of this application provide a receiver image compensation method and system without training sequences to solve the problems of high complexity and hardware requirements of image compensation.

[0006] According to a first aspect of this application, a receiver image compensation method without training sequences is provided, the method comprising: An intermediate frequency (IF) signal is acquired by sampling the signal received by the receiver; the IF signal is a complex analytical signal constructed based on in-phase baseband signals and quadrature baseband signals. The conjugate signal is obtained by finding the conjugate of the intermediate frequency signal; The image coefficients are calculated based on the intermediate frequency signal and the conjugate signal, and the image coefficients are obtained by calculating the correlation between the intermediate frequency signal and the conjugate signal. A mirror compensation matrix is ​​synthesized according to the mirror coefficients. The mirror compensation matrix includes multiple compensation elements, which are obtained by selecting the real and / or imaginary parts of the mirror coefficients. The mirror compensation matrix is ​​used to compensate the in-phase baseband signal and the quadrature baseband signal.

[0007] In some embodiments, acquiring the intermediate frequency signal includes: Obtain the preset power stability range; Monitor the intermediate frequency power of the signal received by the receiver; If the intermediate frequency power is not within the power stability range, acquire the intermediate frequency signal within multiple sampling windows, wherein the sampling window covers at least one sampling point; If the intermediate frequency power is within the power stability range, the intermediate frequency power is continuously monitored.

[0008] In some embodiments, monitoring the intermediate frequency power of the signal received by the receiver includes: The in-phase baseband signal and the quadrature baseband signal of the received signal are sampled by the receiver; Based on the in-phase baseband signal and the quadrature baseband signal, the instantaneous power of each sampling point in the digital domain is calculated, where the instantaneous power is the sum of the squares of the in-phase baseband signal and the quadrature baseband signal; The intermediate frequency power is calculated based on the instantaneous power and the number of sampling points within the sampling window. The intermediate frequency power is the average power of the instantaneous power within the sampling window.

[0009] In some embodiments, calculating the image coefficients based on the intermediate frequency signal and the conjugate signal includes: An imbalance coefficient is calculated based on the intermediate frequency signal and the conjugate signal. The imbalance coefficient is used to estimate the imbalance state by statistical averaging of the intermediate frequency signal and the conjugate signal. The mirror coefficient is calculated based on the imbalance coefficient. The mirror coefficient is the product of the imbalance coefficient and the second-order correction term corresponding to the imbalance coefficient. The second-order correction term is the square of the absolute value of the imbalance coefficient plus 1.

[0010] In some embodiments, calculating the imbalance coefficient based on the intermediate frequency signal and the conjugate signal includes: The autocorrelation result is calculated based on the intermediate frequency signal, and the autocorrelation result is the sum of squares of the intermediate frequency signal corresponding to multiple sampling points; The cross-correlation result is calculated based on the intermediate frequency signal and the conjugate signal, and the cross-correlation result is twice the sum of the products of the intermediate frequency signal and the conjugate signal corresponding to multiple sampling points; The imbalance coefficient is obtained by calculating the ratio of the autocorrelation result to the cross-correlation result.

[0011] In some embodiments, the imbalance coefficient is calculated according to the following formula:

[0012] in, Indicates the imbalance coefficient; Indicates the sampling point index; Indicates the first The in-phase baseband signal at each sampling point; Indicates the first Orthogonal baseband signals at each sampling point; Represents the imaginary unit; The mirror coefficient is calculated according to the following formula:

[0013] in, Indicates the mirror coefficient; This represents the imbalance coefficient.

[0014] In some embodiments, after calculating the image coefficients based on the intermediate frequency signal and the conjugate signal, the method further includes: Obtain the signal to be compensated, wherein the signal to be compensated is a complex analytical signal constructed from the baseband signal of the phase to be compensated and the orthogonal baseband signal to be compensated; The conjugate signal to be compensated is obtained by finding the conjugate of the signal to be compensated. The compensation amount is calculated based on the mirror coefficient and the conjugate signal to be compensated, wherein the compensation amount is the product of the conjugate signal to be compensated and the mirror coefficient; The compensation amount is subtracted from the signal to be compensated to obtain the compensation result.

[0015] In some embodiments, synthesizing a mirror compensation matrix according to the mirror coefficients includes: Select the real and imaginary parts of the mirror coefficients; The compensation element is calculated based on the real and imaginary parts of the mirror image; wherein the compensation element includes a first element, a second element, a third element, and a fourth element; the first element is 1 minus the real part of the mirror image; the second and third elements are the opposites of the imaginary part of the mirror image; the fourth element is 1 plus the real part of the mirror image. The mirror compensation matrix is ​​synthesized based on the compensation elements, and the diagonal elements of the mirror compensation matrix are the second element and the third element.

[0016] In some embodiments, using the mirror compensation matrix to compensate the in-phase baseband signal and the quadrature baseband signal includes: Read the in-phase baseband signal and the quadrature baseband signal from the received signal of the receiver; A compensation matrix is ​​constructed based on the in-phase baseband signal and the quadrature baseband signal; The product of the mirror compensation matrix and the matrix to be compensated is calculated to obtain the compensation result matrix, which includes the compensated in-phase baseband signal and the quadrature baseband signal.

[0017] According to a second aspect of this application, a receiver image compensation system without training sequences is provided, the system comprising: The signal sampling module is used to acquire the intermediate frequency (IF) signal, which is obtained by sampling the signal received by the receiver; the IF signal is a complex analytical signal constructed based on the in-phase baseband signal and the quadrature baseband signal. A conjugate signal generation module is used to obtain a conjugate signal by taking the conjugate of the intermediate frequency signal; The coefficient calculation module is used to calculate the image coefficients based on the intermediate frequency signal and the conjugate signal, wherein the image coefficients are calculated based on the correlation between the intermediate frequency signal and the conjugate signal. A matrix synthesis module is used to synthesize a mirror compensation matrix according to the mirror coefficients. The mirror compensation matrix includes multiple compensation elements, which are obtained by selecting the real part and / or imaginary part of the mirror coefficients. The mirror compensation module is used to compensate the in-phase baseband signal and the quadrature baseband signal using the mirror compensation matrix.

[0018] According to a third aspect of this application, a computer device is provided, including a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, wherein the processor executes the program to implement the above-described receiver image compensation method without training sequence.

[0019] According to a fourth aspect of this application, a storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the above-described receiver image compensation method without training sequences.

[0020] By employing the above technical solutions, embodiments of this application provide a receiver image compensation method and system without training sequences. After obtaining the intermediate frequency (IF) signal and its conjugate signal, the method calculates image coefficients based on the correlation between the IF signal and the conjugate signal, synthesizes an image compensation matrix according to the image coefficients, and then uses the image compensation matrix for image compensation. This method can analyze random spatial radiation signals received by the receiver in free space, utilizing the conjugate relationship between the image signal and the main signal, and obtaining the image compensation coefficients through the conjugate correlation of the IF signal. This method can analyze the image coefficients without requiring dedicated training sequences, reducing the complexity and hardware requirements of image compensation.

[0021] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A schematic diagram of the receiver signal processing flow provided in the embodiments of this application; Figure 2 A schematic flowchart of a receiver image compensation method without training sequences provided in an embodiment of this application; Figure 3 This is a schematic diagram of the mirror compensation signal transmission process provided in an embodiment of this application; Figure 4 This is a schematic diagram illustrating the mirror compensation process performed according to the actual scenario requirements, provided in an embodiment of this application. Figure 5 This is a schematic diagram of the receiver image compensation system without training sequences provided in an embodiment of this application. Detailed Implementation

[0023] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0024] In the embodiments of this application, the receiver image compensation method and system without training sequences can be applied to the wireless signal communication processing of user equipment. User equipment (UE) refers to a terminal device with wireless communication capabilities, including but not limited to smartphones, tablets, IoT terminals, mobile routers, and vehicle-mounted communication devices.

[0025] The wireless signal receiving section of a user equipment (UE) can employ a zero-IF (zero-intermediate frequency) receiver. A zero-IF receiver, also known as a direct-conversion receiver or direct-to-constant receiver, includes a basic structure comprising an antenna, band-pass filter, low-noise amplifier, quadrature demodulator, low-pass filter, variable-gain amplifier, analog-to-digital converter, and digital baseband processor. The antenna captures electromagnetic wave signals in space and transmits them to the UE's internal signal link. The band-pass filter (BPF) and low-noise amplifier (LNA) form a primary signal filtering unit used to filter out out-of-band interference and amplify weak signals.

[0026] The wireless communication process of a user equipment receiver can employ quadrature modulation, where a single radio frequency carrier simultaneously transmits two independent information streams, including amplitude and phase. To recover these two streams of information without distortion, the receiver must extract the in-phase (I) component and the quadrature (Q) component. Therefore, a quadrature demodulator includes a local oscillator (LO) unit, a phase shifter, and a mixer. The LO unit generates a sine wave with the same frequency as the radio frequency carrier. The phase shifter generates the quadrature components of the LO signal, including the I (0°) baseband signal and the Q (90°) baseband signal. Two mixers can be included, one for multiplying the radio frequency signal by the I / Q LO components.

[0027] A low-pass filter (LPF) and a variable gain amplifier (VGA) can form a high-frequency filtering unit to filter out high-frequency artifacts and adjust signal amplitude. An analog-to-digital converter (ADC) can include both I / Q channels to convert analog I / Q signals into digital signals. A digital baseband processor is used for subsequent demodulation, decoding, and other signal processing.

[0028] For example, in wireless communication, the transmitted radio frequency signal can be represented as:

[0029] in, The radio frequency modulated signal emitted by the transmitter is the electromagnetic wave signal transmitted from the antenna; t is the time variable. The in-phase component represents the baseband signal that varies with time and is used to control the amplitude of the cosine component of the carrier wave. The quadrature component represents another independent baseband signal used to control the amplitude of the sinusoidal component of the carrier. Thus, the I and Q signals are orthogonal to each other, meaning their phase difference is 90°, allowing for the simultaneous transmission of two information streams. This refers to the carrier frequency, such as the center frequency of a high-frequency carrier.

[0030] Correspondingly, the local oscillator signal received by the receiver can be expressed as:

[0031]

[0032] in, The I-channel reference signal generated by the receiver's local oscillator; This is the Q-channel reference signal generated by the receiver's local oscillator. At the receiver, the I-channel reference signal is used to correlate with the received signal. Multiply to decompose Q-channel reference signal and Orthogonal, used for demodulation .

[0033] The local oscillator signal, after mixing and low-pass filtering, can be output via one channel. I ( t ) / 2, and Q-channel output - Q ( t The amplitude can be uniquely determined through both I and Q outputs. and phase This allows for demodulation of any modulation scheme. I / Q signals can also be represented as complex baseband signals, i.e. x ( t )= I ( t )+ jQ ( t ),in, j This represents the imaginary unit. Complex baseband signals can contain all the information of the original RF signal, but with a center frequency of 0Hz to reduce the requirements of subsequent ADCs and processing.

[0034] A zero-IF receiver can directly convert received radio frequency signals into baseband signals without any intermediate frequency (IF) processing. The baseband signal can include in-phase (I) and quadrature (Q) baseband signals. The I and Q signals are orthogonal and are used together to recover the signal's amplitude and phase. In a zero-IF receiver, the analog I and Q signal links from the mixer to the analog-to-digital converter (ADC) are called the IF IQ channels of the IF signal.

[0035] The user equipment's processing of receiver signals is essentially a signal conversion process that transforms the electromagnetic wave signals captured by the antenna into a bit stream containing actual communication content. For example... Figure 1 As shown, taking a Long Term Evolution (LTE) signal modulated by Quadrature Phase Shift Keying (QPSK) as an example, signal processing can begin with radio frequency (RF) front-end processing. This involves bandpass filtering to remove spatial multipath signals, noise, and interference signals, preserving the signal within the receiving frequency band and suppressing strong out-of-band signals. Then, an LNA (Light Array Amplifier) ​​amplifies the signal, providing approximately 15-20 dB of signal gain while reducing its own noise figure. For example, if the receiving frequency band is 2 GHz, the bandpass filtering preserves signals near 2 GHz.

[0036] It should be noted that the specific values ​​recorded in the embodiments of this application are merely an example of the application process and do not limit the implementation scheme. Other values ​​that can be inferred by those skilled in the art based on the above example values ​​also fall within the protection scope of this application.

[0037] Then, through down-conversion and quadrature demodulation, the local oscillator frequency is locked near the carrier frequency, such as 2.000 GHz, and the input radio frequency signal is then applied. Simultaneously fed into two mixers, respectively with... and Multiplying these components yields the mixed output. A low-pass filter is then applied to remove the 2fc high-frequency components, retaining the I and Q baseband signals.

[0038] Then, analog domain I / Q signal conditioning is performed, that is, the amplitude of the I / Q signal is adjusted to about 1 / 4 of the full scale of the ADC through a variable gain amplifier (VGA) to make full use of the ADC's dynamic range. DC offset cancellation circuitry can also be used to eliminate DC offset caused by local oscillator leakage or mixer self-mixing.

[0039] Next, analog-to-digital conversion of the I / Q signals is performed, i.e., a dual-channel ADC is used to sample the I and Q signals separately, outputting a digital I / Q sample stream. The sampling rate must satisfy the Nyquist theorem: Fs ≥ 2 × signal bandwidth. For example, for a 20MHz bandwidth, the sampling rate is 30.72MHz. For the digital channel of a 0IF receiver, the sampling rate can be appropriately reduced.

[0040] Finally, the obtained complex baseband signal (I[n]+jQ[n]) is DC offset corrected using a digital baseband processing link, and residual DC is eliminated in the digital domain. I / Q imbalance compensation is performed to correct the amplitude / phase mismatch introduced by the analog mixer and filter. Matched filtering maximizes the signal-to-noise ratio and suppresses inter-symbol interference. A synchronization module is used for symbol timing synchronization, carrier frequency offset estimation compensation, and phase noise compensation. The impulse response of the multipath channel is estimated using a reference signal, and multipath interference is eliminated by an equalizer. The equalized I / Q symbols are then converted into the bit log-likelihood ratio (LLR), and deinterleaved, channel decoded, and cyclic redundancy check (CRC) are performed to finally output the user data bit stream.

[0041] Because zero-IF receivers do not perform intermediate frequency (IF) processing, they cause IF IQ channel imbalance. This means that the I and Q links, which should be perfectly balanced, become unbalanced, exhibiting inconsistencies in amplitude and phase. This IF IQ channel imbalance introduces image interference; for example, interference signals located at negative frequencies may leak to positive frequencies, potentially affecting the signal-to-noise ratio (SNR) in severe cases.

[0042] To mitigate the image problem in receivers, some embodiments require coupling a known signal into the receiver front-end, then extracting the known signal and its mirror signal from the received intermediate frequency signal, and finally calculating the image compensation coefficient. However, the calculation process for the image compensation coefficient requires generating a known training sequence, extracting the known signal and its mirror signal components, and then using complex iterative calculations to obtain the compensation coefficient, increasing the complexity of image compensation and hardware requirements.

[0043] To address the issues of complexity and high hardware requirements in image compensation, some embodiments of this application provide a receiver image compensation method without training sequences. The method uses the random spatial radiation signal received by the user equipment receiver in free space as the analysis object, and utilizes the conjugate relationship between the image signal and the main signal to obtain the image compensation coefficient through the conjugate correlation of the intermediate frequency signal, thereby reducing the complexity and hardware requirements of image compensation.

[0044] The method can be applied to user equipment or electronic devices that establish a communication connection with user equipment and have data processing capabilities. These electronic devices include, but are not limited to, computers, servers, mobile terminals, smart wearable devices, and industrial control machines. For ease of description, the user equipment is used as the execution subject in this embodiment. It should be understood that the method can also be applied to other types of execution subjects, which are not illustrated in this embodiment. Figure 2 As shown, the method includes: S101, Obtain the intermediate frequency signal.

[0045] Before performing image compensation, signal sampling is required, which involves sampling the received signal to obtain the intermediate frequency (IF) signal. This IF signal is a complex analytical signal constructed based on in-phase and quadrature baseband signals.

[0046] To achieve receiver image compensation without training sequences, free-space radiated signals can be used as the analysis object. The signal formed by the free-space radiated signal on the zero-IF receiving link can contain both IF signal and image signal. Therefore, the received signal of the receiver can be sampled to obtain the IF signal.

[0047] like Figure 3 As shown, the intermediate frequency (IF) signal can be obtained by sampling the IF IQ channel of the receiver. Since the IF IQ channel refers to the analog I and Q signal links between the mixer and the analog-to-digital converter (ADC), when acquiring the IF signal, the analog I and Q signal links between the mixer and the ADC can be sampled to obtain the IF signal.

[0048] In some embodiments, when acquiring an intermediate frequency (IF) signal, the received signal can be sampled according to a set sampling point to obtain the IF signal corresponding to different sampling points. For example, the IF signal can be represented as:

[0049] Where n represents the sampling point index; This represents the intermediate frequency signal at the nth sampling point; This represents the in-phase baseband signal at the nth sampling point; represents the orthogonal baseband signal at the nth sampling point; j represents the imaginary unit.

[0050] S102. Obtain the conjugate signal by finding the conjugate of the intermediate frequency signal.

[0051] When performing receiver image compensation without training sequences, correlation detection can be performed using the received intermediate frequency (IF) signal and its own conjugate signal. Therefore, after acquiring the IF signal, the conjugate signal can be obtained by finding the conjugate of the IF signal.

[0052] In some embodiments, when obtaining a conjugate signal by finding the conjugate of the intermediate frequency (IF) signal, the in-phase baseband signal and the quadrature baseband signal can be read from the IF signal first, and then the quadrature baseband signal can be inverted to obtain the conjugate imaginary part. Then, the conjugate signal is generated by combining the in-phase baseband signal as the conjugate real part with the conjugate imaginary part.

[0053] For example, in acquiring intermediate frequency signals Then, the in-phase baseband signal can be extracted from the intermediate frequency signal. I ( n and orthogonal baseband signal Q ( n ). Then, regarding the orthogonal baseband signal... Q ( n Inverting this gives the opposite signal of the quadrature baseband signal, i.e., "- Q ( n The conjugate imaginary part is obtained by taking the in-phase baseband signal as the conjugate real part. Then, the conjugate imaginary part and the conjugate real part are combined to form the conjugate signal, which can be represented as:

[0054] in, n Indicates the sampling point index; Indicates the first n The intermediate frequency signal at each sampling point; Indicates the first n The in-phase baseband signal at each sampling point; Indicates the first n Orthogonal baseband signals at each sampling point; j It represents the imaginary unit.

[0055] S103. Calculate the image coefficients based on the intermediate frequency signal and the conjugate signal.

[0056] After acquiring the intermediate frequency (IF) signal and its conjugate signal, correlation calculations can be performed on the IF signal and its conjugate signal to calculate the image coefficients. The image coefficients are obtained based on the correlation calculation between the IF signal and its conjugate signal.

[0057] For example, for intermediate frequency signals Its conjugate signal is Therefore, the coefficient of the mirror image coef The correlation can be obtained by calculating the correlation, where the correlation between the intermediate frequency signal and the conjugate signal can be expressed as: corr ( F ( n ), F' ( n )).

[0058] In some embodiments, when calculating the image coefficient based on the intermediate frequency (IF) signal and the conjugate signal, an imbalance coefficient can first be calculated based on the IF signal and the conjugate signal. This imbalance coefficient is used to estimate the imbalance state by statistically averaging the IF signal and the conjugate signal. That is, the imbalance coefficient can quantify the degree of amplitude and phase imbalance between the I-path and the Q-path.

[0059] To calculate the imbalance coefficient, when calculating the imbalance coefficient based on the intermediate frequency (IF) signal and its conjugate signal, the autocorrelation result can be calculated first from the IF signal, and then the cross-correlation result can be calculated from the IF signal and its conjugate signal. The autocorrelation result is the sum of squares of the IF signals corresponding to multiple sampling points; the cross-correlation result is twice the sum of the products of the IF signals and their conjugate signals corresponding to multiple sampling points. The imbalance coefficient is then obtained by calculating the ratio of the autocorrelation result to the cross-correlation result.

[0060] For example, the imbalance coefficient is calculated using the following formula:

[0061] in, Indicates the imbalance coefficient; Indicates the sampling point index; Indicates the first The in-phase baseband signal at each sampling point; Indicates the first Orthogonal baseband signals at each sampling point; It represents the imaginary unit.

[0062] After calculating the imbalance coefficient, the mirror coefficient is then calculated based on the imbalance coefficient. The mirror coefficient is the product of the imbalance coefficient and the corresponding second-order correction term, where the second-order correction term is the square of the absolute value of the imbalance coefficient plus 1.

[0063] For example, the mirror coefficient is calculated using the following formula:

[0064] in, Indicates the mirror coefficient; This represents the imbalance coefficient.

[0065] Based on the mirror coefficient calculation method described in the above embodiments, the user equipment can estimate the imbalance error of the I / Q channels, i.e., the imbalance coefficient, during communication by using the intermediate frequency signal and conjugate signal corresponding to multiple sampling points over a period of time. cc Then estimate cc Converted to actual compensation coefficient coef It is used to correct subsequent received signals.

[0066] S104. Synthesize the mirror compensation matrix according to the mirror coefficients.

[0067] After calculating the mirror coefficients, a mirror compensation matrix can be synthesized according to the mirror coefficients. The mirror compensation matrix includes multiple compensation elements, and the compensation elements are obtained by selecting the real part and / or imaginary part of the mirror coefficients.

[0068] For example, a mirror compensation matrix can be a 2×2 compensation matrix M used to correct unbalanced I / Q signals. This mirror compensation matrix can include four compensation elements, which can form a 2×2 compensation matrix with two rows and two columns, i.e.:

[0069] Where M represents the mirror compensation matrix; M11 represents the compensation element in the first row and first column, and is called the first element; M12 represents the compensation element in the first row and second column, and is called the second element; M21 represents the compensation element in the second row and first column, and is called the third element; M22 represents the compensation element in the second row and second column, and is called the fourth element.

[0070] To synthesize the mirror compensation matrix, in some embodiments, when synthesizing the mirror compensation matrix according to the mirror coefficients, the real and imaginary parts of the mirror coefficients can be selected, and compensation elements can be calculated based on the real and imaginary parts. The compensation elements include a first element, a second element, a third element, and a fourth element. The first element is 1 minus the real part; the second and third elements are the opposites of the imaginary parts; and the fourth element is 1 plus the real part. Then, the mirror compensation matrix is ​​synthesized based on the compensation elements. In the mirror compensation matrix, the diagonal elements are the second and third elements, and the front diagonal elements are the first and fourth elements.

[0071] For example, the real part of the mirrored coefficients can be selected using the real() function, i.e., the real part of the mirrored coefficients is real(coef). Similarly, the imaginary part of the mirrored coefficients can be selected using the imaginary() function, i.e., the imaginary part of the mirrored coefficients is imagin(coef).

[0072] Then, the compensation elements are calculated based on the real part *real(coef)* and the imaginary part *imag(coef)*. For the first element, it can be obtained by calculating the difference between 1 and the real part, i.e., M11 = 1 - real(coef). Similarly, for the second element, it can be obtained by calculating the negative of the imaginary part, i.e., M12 = -imag(coef). The third element is the same as the second element, also obtained by calculating the negative of the imaginary part, i.e., M21 = -imag(coef). The fourth element can be obtained by calculating the sum of 1 and the real part, i.e., M22 = 1 + real(coef).

[0073] Then, based on the compensation elements, a mirror compensation matrix is ​​synthesized, that is:

[0074] Where M represents the mirror compensation matrix; M11 represents the compensation element in the first row and first column; M12 represents the compensation element in the first row and second column; M21 represents the compensation element in the second row and first column; M22 represents the compensation element in the second row and second column; real(coef) represents the real part of the mirror; and imag(coef) represents the imaginary part of the mirror.

[0075] The synthesized image compensation matrix can be stored in the user equipment's storage medium for image compensation of subsequent received signals. That is, when image compensation is needed, the compensation algorithm program can call the image compensation matrix from the storage medium and perform signal processing on the subsequent received signals based on the image compensation matrix to compensate for possible image effects in the signal.

[0076] In some embodiments, the mirror compensation matrix can be updated in real time during signal transmission. Specifically, the user equipment can set multiple sampling points according to a preset sampling frequency, and sample the intermediate frequency signal based on these sampling points. Then, when the number of signal samples reaches a preset threshold, the mirror coefficients are calculated according to the mirror coefficient calculation method provided in the above embodiments. A new mirror compensation matrix is ​​then synthesized using the calculated mirror coefficients, and the new mirror compensation matrix replaces the mirror compensation matrix stored in the storage medium, so that the user equipment can use the newly synthesized mirror compensation matrix for mirror compensation calculations in subsequent signal processing.

[0077] S105. Use a mirror compensation matrix to compensate for in-phase baseband signals and quadrature baseband signals.

[0078] After synthesizing the mirror compensation matrix, mirror compensation can be performed based on the mirror compensation matrix, that is, the mirror compensation matrix can be used to compensate for in-phase baseband signals and quadrature baseband signals.

[0079] During image compensation, the user equipment can use the received signal from the receiver as the signal to be compensated. The signal to be compensated is also a complex analytical signal constructed based on the in-phase baseband signal and the quadrature baseband signal, that is, the signal to be compensated includes the in-phase baseband signal (I) and the quadrature baseband signal (Q). Then, the image compensation matrix is ​​used to perform compensation operations on the in-phase baseband signal and the quadrature baseband signal in the signal to be compensated to generate the compensated in-phase baseband signal and the quadrature baseband signal.

[0080] In some embodiments, mirror compensation can be performed using matrix multiplication. When compensating in-phase and quadrature baseband signals using a mirror compensation matrix, the in-phase and quadrature baseband signals can first be read from the received signal at the receiver. Then, a compensation matrix is ​​constructed based on the in-phase and quadrature baseband signals. Finally, the product of the mirror compensation matrix and the compensation matrix is ​​calculated to obtain the compensation result matrix. The compensation result matrix includes the compensated in-phase and quadrature baseband signals.

[0081] For example, after synthesizing the image compensation matrix M, the user equipment can acquire the received signal from the receiver. F in This serves as the signal to be compensated. And from the received signal... F in Read the in-phase baseband signal to be compensated and the orthogonal baseband signal to be compensated This is used to form the compensation matrix. The compensation matrix is ​​a matrix composed of the row vectors of the timing of the in-phase baseband signal to be compensated and the row vectors of the timing of the orthogonal baseband signal to be compensated when the real-time wireless data stream flows through the current module. For example, the operational dimension of the compensation matrix is ​​2×L, where L represents the number of elements contained in the row vectors.

[0082] Then, the product of the mirror compensation matrix and the matrix to be compensated is calculated to obtain the compensation result matrix, which is then compared with the baseband signal of the phase to be compensated. and the orthogonal baseband signal to be compensated Correspondingly, the compensated in-phase baseband signal With the compensated orthogonal baseband signal Since it is also a row vector, the compensation result matrix is ​​composed of the compensated in-phase baseband signal. With the compensated orthogonal baseband signal A matrix composed of row vectors. Therefore, the compensated in-phase baseband signal and orthogonal baseband signal as follows:

[0083] in, This represents the compensated in-phase baseband signal; M11 represents the compensated quadrature baseband signal; M12 represents the compensated element in the first row and first column; M21 represents the compensated element in the second row and first column; M22 represents the compensated element in the second row and second column. Indicates the baseband signal of the phase to be compensated; This represents the orthogonal baseband signal to be compensated.

[0084] In some embodiments, for compensation results with mirror interference, a non-matrix method can also be used, that is, the mirror coefficients are calculated first. Then, the in-phase baseband signal and quadrature baseband signal can be read from the received signal of the receiver to obtain the phase baseband signal to be compensated. and the orthogonal baseband signal to be compensated Then, based on the baseband signal of the phase to be compensated... and the orthogonal baseband signal to be compensated Construct the complex analytic signal representation of the signal to be compensated, i.e. And the conjugate signal to be compensated is obtained by finding the conjugate, i.e. Then, based on the mirror coefficient... and conjugate signal to be compensated Calculate the compensation amount, and then subtract the calculated compensation amount from the complex analytic signal of the signal to be compensated to obtain the compensation result. The compensated signal can then be represented as follows:

[0085] in, This represents the compensated in-phase baseband signal; Represents the imaginary number symbol; This represents the compensated orthogonal baseband signal; Indicates the baseband signal of the phase to be compensated; This represents the orthogonal baseband signal to be compensated. The calculation process for the above compensation result can be built into the signal processing chip of the user equipment receiver, used to perform image compensation on the received signal within a specific period.

[0086] By applying the technical solutions of the above embodiments, the receiver image compensation method without training sequences described in the above embodiments can use free-space radiated signals as the analysis object, analyze image parameters without the need for professional training sequences, and directly synthesize compensation matrices using image parameters without complex calculations. Therefore, the method can achieve receiver image compensation without training sequences, reducing algorithm complexity, compensation algorithm process complexity, and hardware requirements, thereby solving the problems of high complexity and hardware requirements in image compensation.

[0087] In some embodiments, as a refinement and extension of the specific implementation of the above embodiments, and to fully illustrate the specific implementation process of this embodiment, some embodiments of this application also provide a receiver image compensation method without training sequences. The difference between this method and the above embodiments is that, according to the actual scenario requirements, the image parameter coef can be calculated within a certain time period, such as... Figure 4 As shown, the method includes: S201. Obtain the preset power stability range; S202, Intermediate frequency power of the signal received by the monitoring receiver; S203. If the intermediate frequency power is not within the power stability range, acquire the intermediate frequency signal within multiple sampling windows; S204. If the intermediate frequency power is within the power stability range, continue to monitor the intermediate frequency power.

[0088] When performing image compensation, the user equipment first obtains a preset power stability range based on the actual needs of the intermediate frequency power detection scenario. This power stability range is a power parameter range determined by preset minimum and maximum stable power, i.e., the power stability range is [P]. min P max ].

[0089] Then, the intermediate frequency (IF) power of the received signal is monitored. In some embodiments, the IF power can be calculated based on the digital power of I / Q sampling. Therefore, when monitoring the IF power of the received signal, the in-phase baseband signal and the quadrature baseband signal of the received signal can be sampled, and the instantaneous power at each sampling point in the digital domain can be calculated based on the in-phase and quadrature baseband signals. The instantaneous power is the sum of the squares of the in-phase and quadrature baseband signals. Then, the IF power is calculated based on the instantaneous power and the number of sampling points within the sampling window; that is, the IF power is the average power of the instantaneous power within the sampling window.

[0090] For example, when monitoring intermediate frequency power, in the digital domain, the instantaneous power P at each sampling point can be calculated by sampling the in-phase baseband signal and the quadrature baseband signal, i.e.:

[0091] in, This represents the instantaneous power at the nth sampling point; This represents the in-phase baseband signal at the nth sampling point; This represents the orthogonal baseband signal at the nth sampling point.

[0092] Then, the number of sampling points contained in the sampling window is obtained, and based on the number of sampling points and the instantaneous power, the average power within the corresponding time period of the sampling window is calculated, i.e.:

[0093] in, This represents the average power, i.e., the intermediate frequency power; N represents the number of sampling points included in the sampling window; This represents the in-phase baseband signal at the nth sampling point; This represents the orthogonal baseband signal at the nth sampling point.

[0094] It should be noted that intermediate frequency (IF) power can be obtained not only through digital power calculation based on I / Q sampling, but also through analog domain power detection and measurement using a spectrum analyzer. When obtaining IF power through analog domain power detection, a dedicated power detection circuit can be used before the ADC to measure the analog baseband signal and calculate the IF power based on the analog baseband signal. When measuring IF power using a spectrum analyzer, hardware measurement devices such as a spectrum analyzer can be used to measure the power of the IF signal.

[0095] After monitoring and obtaining the intermediate frequency (IF) power of the received signal, the IF power can be compared with the power stability range. If the IF power is within the power stability range, it indicates that the current IF signal transmission is normal and there will be no image problem affecting the signal transmission quality. At this time, image compensation can be performed according to the currently set image compensation method, or image compensation can be left unperformed, and the IF power can be continuously monitored.

[0096] If the intermediate frequency (IF) power is not within the stable power range, it indicates that the IF power is either too high or too low. Continued sampling is needed to increase the cumulative length of the imbalance coefficient, thereby obtaining a more stable and ideal image coefficient (coef). Therefore, when the IF power is not within the stable power range, IF signals within multiple sampling windows can be acquired, where each sampling window covers at least one sampling point. Then, following the image compensation method described in the above embodiment, conjugate signals are obtained from the IF signals within the multiple sampling windows, and image coefficients are calculated based on the IF signals and conjugate signals. Finally, an image compensation matrix is ​​synthesized based on the image coefficients, and signal compensation is performed using the image compensation matrix.

[0097] In some embodiments, when determining that the intermediate frequency power is in the power stable range, it can also be determined whether to update the coefficient based on the image coefficient. That is, after the power reaches the standard, it is determined whether the calculated image coefficient coef is less than the preset coefficient threshold. If the image coefficient coef is less than or equal to the preset coefficient threshold, there is no need to update the image coefficient coef; if the image coefficient coef is greater than the preset coefficient threshold, a new image coefficient coef is updated and calculated.

[0098] For example, if the modulus of the mirror coefficient *coef* ranges from [0, 1], then to achieve a mirror compensation of -40 dBc, the corresponding coefficient threshold is approximately 0.01, meaning the modulus of the mirror coefficient *coef* must be 0.01. When the mirror coefficient *coef* is less than or equal to 0.01, no update is needed. However, when the mirror coefficient *coef* is greater than 0.01, a new mirror coefficient *coef* is calculated.

[0099] By applying the technical solutions of the above embodiments, the receiver image compensation method without training sequences described in the above embodiments can, after obtaining a preset power stability range, monitor the intermediate frequency power of the received signal and determine whether the intermediate frequency power is within the power stability range. When the intermediate frequency power is not within the power stability range, it can acquire intermediate frequency signals within multiple sampling windows, thereby calculating a more stable and ideal image coefficient (coef) when the intermediate frequency power is large or small. This allows the received signal processing process to calculate the image coefficient within a certain time period according to the actual scenario requirements, improving the accuracy of obtaining the image coefficient and reducing the data update frequency, further reducing the complexity and hardware requirements of the image compensation algorithm.

[0100] In some embodiments, as a specific implementation of the receiver image compensation method without training sequences described in the above embodiments, some embodiments of this application also provide a receiver image compensation system without training sequences, such as... Figure 5 As shown, the system includes: The signal sampling module is used to acquire the intermediate frequency (IF) signal, which is obtained by sampling the signal received by the receiver; the IF signal is a complex analytical signal constructed based on the in-phase baseband signal and the quadrature baseband signal. A conjugate signal generation module is used to obtain a conjugate signal by taking the conjugate of the intermediate frequency signal; The coefficient calculation module is used to calculate the image coefficients based on the intermediate frequency signal and the conjugate signal, wherein the image coefficients are calculated based on the correlation between the intermediate frequency signal and the conjugate signal. A matrix synthesis module is used to synthesize a mirror compensation matrix according to the mirror coefficients. The mirror compensation matrix includes multiple compensation elements, which are obtained by selecting the real part and / or imaginary part of the mirror coefficients. The mirror compensation module is used to compensate the in-phase baseband signal and the quadrature baseband signal using the mirror compensation matrix.

[0101] By applying the technical solutions of the above embodiments, the receiver image compensation system without training sequences described in the above embodiments can obtain the intermediate frequency (IF) signal through the signal sampling module, and obtain the conjugate signal of the IF signal through the conjugate signal generation module. This allows the coefficient calculation module to calculate the image coefficients based on the correlation between the IF signal and the conjugate signal. The matrix synthesis module then synthesizes the image compensation matrix according to the image coefficients, and the image compensation module uses the image compensation matrix to perform image compensation. The system can take the random spatial radiation signal received by the receiver in free space as the analysis object, and obtain the image compensation coefficients through the conjugate correlation of the IF signal by utilizing the conjugate relationship between the image signal and the main signal. The system can analyze the image coefficients without a dedicated training sequence, reducing the complexity and hardware requirements of image compensation.

[0102] It should be noted that other corresponding descriptions of the functional units involved in the receiver image compensation system without training sequence provided in the embodiments of this application can be found in the corresponding descriptions in the receiver image compensation method without training sequence provided in the above embodiments, and will not be repeated here.

[0103] This application also provides a computer device, specifically a personal computer, server, network device, etc. The computer device includes a bus, processor, memory, and communication interface, and may also include input / output interfaces and a display device. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database of the computer device stores location information. The network interface of the computer device is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements the steps in the various method embodiments.

[0104] Those skilled in the art will understand that the structure of the computer device described above is only a partial structure related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. A specific computer device may include more or fewer components, or combine certain components, or have different component arrangements.

[0105] In one embodiment, a computer-readable storage medium is also provided, which may be non-volatile or volatile, and a computer program is stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0106] In one embodiment, a computer program product is also provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0107] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0108] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods.

[0109] Any references to memory, database, or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc.

[0110] Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can take many forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0111] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchain. The processors involved in the embodiments provided in this application may be, but are not limited to, general-purpose processors, graphics processors, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc.

[0112] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0113] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A receiver image compensation method without training sequences, characterized in that, The method includes: An intermediate frequency (IF) signal is acquired by sampling the signal received by the receiver; the IF signal is a complex analytical signal constructed based on in-phase baseband signals and quadrature baseband signals. The conjugate signal is obtained by finding the conjugate of the intermediate frequency signal; The image coefficients are calculated based on the intermediate frequency signal and the conjugate signal, and the image coefficients are obtained by calculating the correlation between the intermediate frequency signal and the conjugate signal. A mirror compensation matrix is ​​synthesized according to the mirror coefficients. The mirror compensation matrix includes multiple compensation elements, which are obtained by selecting the real and / or imaginary parts of the mirror coefficients. The mirror compensation matrix is ​​used to compensate the in-phase baseband signal and the quadrature baseband signal.

2. The receiver image compensation method without training sequences according to claim 1, characterized in that, Acquiring intermediate frequency signals, including: Obtain the preset power stability range; Monitor the intermediate frequency power of the signal received by the receiver; If the intermediate frequency power is not within the power stability range, acquire the intermediate frequency signal within multiple sampling windows, wherein the sampling window covers at least one sampling point; If the intermediate frequency power is within the power stability range, the intermediate frequency power is continuously monitored.

3. The receiver image compensation method without training sequences according to claim 2, characterized in that, Monitoring the intermediate frequency power of the signal received by the receiver includes: The in-phase baseband signal and the quadrature baseband signal of the received signal are sampled by the receiver; Based on the in-phase baseband signal and the quadrature baseband signal, the instantaneous power of each sampling point in the digital domain is calculated, where the instantaneous power is the sum of the squares of the in-phase baseband signal and the quadrature baseband signal; The intermediate frequency power is calculated based on the instantaneous power and the number of sampling points within the sampling window. The intermediate frequency power is the average power of the instantaneous power within the sampling window.

4. The receiver image compensation method without training sequences according to claim 1, characterized in that, Calculating the image coefficients based on the intermediate frequency signal and the conjugate signal includes: An imbalance coefficient is calculated based on the intermediate frequency signal and the conjugate signal. The imbalance coefficient is used to estimate the imbalance state by statistical averaging of the intermediate frequency signal and the conjugate signal. The mirror coefficient is calculated based on the imbalance coefficient. The mirror coefficient is the product of the imbalance coefficient and the second-order correction term corresponding to the imbalance coefficient. The second-order correction term is the square of the absolute value of the imbalance coefficient plus 1.

5. The receiver image compensation method without training sequences according to claim 4, characterized in that, The imbalance coefficient is calculated based on the intermediate frequency signal and the conjugate signal, including: The autocorrelation result is calculated based on the intermediate frequency signal, and the autocorrelation result is the sum of squares of the intermediate frequency signal corresponding to multiple sampling points; The cross-correlation result is calculated based on the intermediate frequency signal and the conjugate signal, and the cross-correlation result is twice the sum of the products of the intermediate frequency signal and the conjugate signal corresponding to multiple sampling points; The imbalance coefficient is obtained by calculating the ratio of the autocorrelation result to the cross-correlation result.

6. The receiver image compensation method without training sequences according to claim 5, characterized in that, The imbalance coefficient is calculated according to the following formula: in, Indicates the imbalance coefficient; Indicates the sampling point index; Indicates the first The in-phase baseband signal at each sampling point; Indicates the first Orthogonal baseband signals at each sampling point; Represents the imaginary unit; The mirror coefficient is calculated according to the following formula: in, Indicates the mirror coefficient; This represents the imbalance coefficient.

7. The receiver image compensation method without training sequences according to claim 1, characterized in that, After calculating the image coefficients based on the intermediate frequency signal and the conjugate signal, the method further includes: Obtain the signal to be compensated, wherein the signal to be compensated is a complex analytical signal constructed from the baseband signal of the phase to be compensated and the orthogonal baseband signal to be compensated; The conjugate signal to be compensated is obtained by finding the conjugate of the signal to be compensated. The compensation amount is calculated based on the mirror coefficient and the conjugate signal to be compensated, wherein the compensation amount is the product of the conjugate signal to be compensated and the mirror coefficient; The compensation amount is subtracted from the signal to be compensated to obtain the compensation result.

8. The receiver image compensation method without training sequences according to claim 1, characterized in that, The mirror compensation matrix is ​​synthesized according to the aforementioned mirror coefficients, including: Select the real and imaginary parts of the mirror coefficients; The compensation element is calculated based on the real and imaginary parts of the mirror image; wherein the compensation element includes a first element, a second element, a third element, and a fourth element; the first element is 1 minus the real part of the mirror image; the second and third elements are the opposites of the imaginary part of the mirror image; the fourth element is 1 plus the real part of the mirror image. The mirror compensation matrix is ​​synthesized based on the compensation elements, and the diagonal elements of the mirror compensation matrix are the second element and the third element.

9. The receiver image compensation method without training sequences according to claim 1, characterized in that, Compensating the in-phase baseband signal and the quadrature baseband signal using the mirror compensation matrix includes: Read the in-phase baseband signal and the quadrature baseband signal from the received signal of the receiver; A compensation matrix is ​​constructed based on the in-phase baseband signal and the quadrature baseband signal; The product of the mirror compensation matrix and the matrix to be compensated is calculated to obtain the compensation result matrix, which includes the compensated in-phase baseband signal and the quadrature baseband signal.

10. A receiver image compensation system without training sequences, characterized in that, The system includes: The signal sampling module is used to acquire the intermediate frequency (IF) signal, which is obtained by sampling the signal received by the receiver; the IF signal is a complex analytical signal constructed based on the in-phase baseband signal and the quadrature baseband signal. A conjugate signal generation module is used to obtain a conjugate signal by taking the conjugate of the intermediate frequency signal; The coefficient calculation module is used to calculate the image coefficients based on the intermediate frequency signal and the conjugate signal, wherein the image coefficients are calculated based on the correlation between the intermediate frequency signal and the conjugate signal. A matrix synthesis module is used to synthesize a mirror compensation matrix according to the mirror coefficients. The mirror compensation matrix includes multiple compensation elements, which are obtained by selecting the real part and / or imaginary part of the mirror coefficients. The mirror compensation module is used to compensate the in-phase baseband signal and the quadrature baseband signal using the mirror compensation matrix.

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