Method, device and apparatus for compensating carrier phase and IQ imbalance of communication receiver

Abstract

The present disclosure provides a method, apparatus, and device for compensating for carrier phase and IQ imbalance of a communication receiver, which can be applied to the field of communication signal processing technology. The method includes: sampling a received signal of a communication receiver to obtain a received signal sequence, wherein the communication receiver includes a transmitter and a receiver, and the receiver processes the transmitted signal from the transmitter to obtain a received signal; calculating the expectation and covariance matrices of the received signal sequence, and constructing a likelihood function corresponding to the received signal sequence based on the expectation and covariance matrices; derivatizing the logarithmic function of the likelihood function to obtain a set of estimation equations corresponding to multiple parameters to be estimated; iteratively solving the set of estimation equations according to a predetermined number of iterations to obtain multiple target estimation parameters corresponding to the multiple parameters to be estimated; and compensating the received signal sequence based on the target estimation parameters to obtain a target signal sequence.

Description

Technical Field

[0001] The present disclosure relates to the technical field of communication signal processing, and more particularly, to a method, apparatus, and device for compensating for carrier phase and IQ imbalance of a communication receiver. Background Art

[0002] Zero-IF receivers have a simple architecture and are currently widely used in the field of communication signal processing. However, due to imperfect hardware, I (in-phase) Q (quadrature) imbalance exists. That is, the gain and phase of the I and Q branch signals are not completely matched. IQ imbalance will cause deviations in the Q signal, thereby affecting the deviation of the signal and causing image interference, reducing the signal-to-noise ratio.

[0003] In the process of implementing the concept of the present disclosure, the inventors discovered that it is difficult to take into account the influence of carrier phase in the compensation of IQ imbalance in related technologies and the estimation accuracy is low. Summary of the Invention

[0004] In view of this, the present disclosure provides a method, apparatus, and device for compensating for carrier phase and IQ imbalance of a communication receiver.

[0005] One aspect of the present disclosure provides a method for compensating carrier phase and IQ imbalance of a communication receiver, comprising:

[0006] A received signal of a communication receiver is sampled to obtain a received signal sequence, wherein the communication receiver includes a transmitter and a receiver, the receiver processes the transmitted signal from the transmitter to obtain a received signal, the received signal includes an I-branch received signal and a Q-branch received signal, and the transmitted signal includes an I-branch transmitted signal and a Q-branch transmitted signal; the expectation and covariance matrices of the received signal sequence are calculated, and a likelihood function corresponding to the received signal sequence is constructed based on the expectation and covariance matrices; the logarithmic function of the likelihood function is differentiated to obtain a group of estimation equations corresponding to multiple parameters to be estimated, wherein the multiple parameters to be estimated include a carrier phase parameter, a receiving end gain imbalance parameter, a receiving end phase imbalance parameter, a transmitting end gain imbalance parameter, and a transmitting end phase imbalance parameter; the estimation equation group is iteratively solved according to a predetermined number of iterations to obtain multiple target estimation parameters corresponding to the multiple parameters to be estimated; the received signal sequence is compensated based on the target estimation parameters to obtain a target signal sequence.

[0007] According to an embodiment of the present disclosure, the estimation equation group is iteratively solved according to a predetermined number of iterations to obtain target estimation parameters, including: performing partial derivative processing on each equation in the estimation equation group to obtain a Jacobian matrix; and performing Newton iteration processing on the estimation equation group corresponding to the predetermined number of iterations according to the Jacobian matrix to obtain target estimation parameters.

[0008] According to an embodiment of the present disclosure, the predetermined number of iterations includes 3 or 4.

[0009] According to an embodiment of the present disclosure, the expression of the likelihood function is:

[0010]

[0011] in, represents the likelihood function, k represents the sampling point, represents the covariance matrix, Indicates receiving signal, Express expectations.

[0012] According to an embodiment of the present disclosure, the expression of the received signal sequence is:

[0013]

[0014] in, To receive the signal, I branch receives the signal, The Q branch receives the signal. is the transmission matrix, is the carrier phase parameter, is the gain imbalance parameter at the receiving end, is the phase imbalance parameter at the receiving end, is the transmitter gain imbalance parameter, is the phase imbalance parameter at the transmitter, I is the branch transmission signal, For Q split transmission signal, is the noise signal of the I branch, is the noise signal of the Q branch.

[0015] According to an embodiment of the present disclosure, the expression of the transmission matrix is:

[0016] .

[0017] According to an embodiment of the present disclosure, the target estimation parameters include a carrier phase estimation parameter, a receiving end gain imbalance estimation parameter, a receiving end phase imbalance estimation parameter, a transmitting end gain imbalance estimation parameter, and a transmitting end phase imbalance estimation parameter. The target signal sequence is expressed as:

[0018]

[0019] in, represents the target signal sequence, represents the I branch compensation signal corresponding to the I branch receiving signal, represents the Q branch compensation signal corresponding to the Q branch receiving signal, represents the inverse transmission matrix, represents the carrier phase estimation parameter, represents the receiver gain imbalance estimation parameter, represents the receiver phase imbalance estimation parameter, represents the transmitter gain imbalance estimation parameter, represents the transmitter phase imbalance estimation parameter, I branch receives the signal, Splits the received signal for Q.

[0020] According to an embodiment of the present disclosure, the estimation equation group includes equations corresponding to multiple parameters to be estimated, and the logarithmic function of the likelihood function is differentiated to obtain the estimation equation group corresponding to the multiple parameters to be estimated, including: calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the carrier phase parameter to obtain a first equation corresponding to the carrier phase parameter; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the receiving end gain imbalance parameter to obtain a second equation corresponding to the receiving end gain imbalance parameter; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the receiving end phase imbalance parameter to obtain a third equation corresponding to the receiving end phase imbalance parameter; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the transmitting end gain imbalance parameter to obtain a fourth equation corresponding to the transmitting end gain imbalance parameter; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the transmitting end phase imbalance parameter to obtain a fifth equation corresponding to the transmitting end phase imbalance parameter.

[0021] Another aspect of the present disclosure provides a compensation apparatus for carrier phase and IQ imbalance of a communication receiver, comprising:

[0022] a sampling module, configured to sample a received signal of a communication receiver to obtain a received signal sequence, wherein the communication receiver includes a transmitting end and a receiving end, the receiving end processes a transmitted signal from the transmitting end to obtain a received signal, the received signal includes an I-branch received signal and a Q-branch received signal, and the transmitted signal includes an I-branch transmitted signal and a Q-branch transmitted signal;

[0023] A construction module is used to calculate the expectation and covariance matrix of the received signal sequence, and to construct a likelihood function corresponding to the received signal sequence based on the expectation and covariance matrix;

[0024] a derivation module, configured to derive a logarithmic function of the likelihood function to obtain a set of estimation equations corresponding to a plurality of parameters to be estimated, wherein the plurality of parameters to be estimated include a carrier phase parameter, a receiving end gain imbalance parameter, a receiving end phase imbalance parameter, a transmitting end gain imbalance parameter, and a transmitting end phase imbalance parameter;

[0025] An iterative module, configured to iteratively solve the estimation equations according to a predetermined number of iterations to obtain a plurality of target estimation parameters corresponding to the plurality of parameters to be estimated;

[0026] The compensation module is used to compensate the received signal sequence according to the target estimation parameter to obtain the target signal sequence.

[0027] Another aspect of the present disclosure provides an electronic device, comprising:

[0028] one or more processors;

[0029] a memory for storing one or more programs,

[0030] When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described above.

[0031] According to an embodiment of the present disclosure, a likelihood function corresponding to the received signal sequence is constructed by the expectation and covariance matrix of the received signal sequence, the likelihood function is differentiated to obtain a group of estimation equations, and the group of estimation equations is iteratively solved to obtain estimated values ​​of the carrier phase parameters, the receiving end gain imbalance parameters, the receiving end phase imbalance parameters, the transmitting end gain imbalance parameters and the transmitting end phase imbalance parameters, namely the target estimation parameters, and then the received signal sequence is compensated according to the target estimation parameters. Since the likelihood function is used to accurately estimate the parameters to be estimated, the influence of the carrier phase and the imbalance of the transmitting end can be considered at the same time, and multiple parameters to be estimated can be separately estimated and compensated according to actual needs, which effectively improves the accuracy of the estimation and thus improves the signal quality after compensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0033] Figure 1 The flowchart of the method for compensating for carrier phase and IQ imbalance of a communication receiver according to an embodiment of the present disclosure is schematically shown.

[0034] Figure 2 The figure schematically shows an architecture diagram of a signal transmission model according to an embodiment of the present disclosure.

[0035] Figure 3a The figure schematically shows a constellation simulation diagram of a received signal sequence before compensation according to an embodiment of the present disclosure.

[0036] Figure 3bThe constellation simulation diagram of the compensated received signal sequence according to an embodiment of the present disclosure is schematically shown.

[0037] Figure 4 A curve diagram schematically illustrates the impact of a change in a phase imbalance parameter at a receiving end on the mean square error and the Cramer-Rao lower bound according to an embodiment of the present disclosure.

[0038] Figure 5 A curve diagram schematically illustrates the effect of a change in the length of a received signal sequence on the mean square error and the Cramer-Rao lower bound according to an embodiment of the present disclosure.

[0039] Figure 6 A curve diagram schematically illustrates the impact of carrier phase changes on mean square error and Cramer-Rao lower bound according to an embodiment of the present disclosure.

[0040] Figure 7 A curve diagram schematically illustrates the impact of a change in a gain imbalance parameter at the receiving end on the mean square error and the Cramer-Rao lower bound according to an embodiment of the present disclosure.

[0041] Figure 8 A curve diagram schematically illustrates the effect of a change in the signal-to-noise ratio on the mean square error and the Cramer-Rao lower bound according to an embodiment of the present disclosure.

[0042] Figure 9 The figure schematically shows a block diagram of a device for compensating for carrier phase and IQ imbalance of a communication receiver according to an embodiment of the present disclosure.

[0043] Figure 10 The block diagram schematically shows an electronic device suitable for implementing a method for compensating a carrier phase and IQ imbalance for a communication receiver according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0044] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0045] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0046] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0047] When expressions such as "at least one of A, B, and C, etc." are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0048] The compensation methods for IQ imbalance in related technologies can be divided into blind signal compensation and pilot sequence compensation. Among them, blind signal compensation requires the use of the first-order or second-order statistical characteristics of the signal, which makes the compensation algorithm more complex and dependent on more data. Compared with the compensation method based on the pilot sequence, the estimation accuracy is usually lower. Pilot sequence compensation is usually more practical in fields such as satellite communications. However, the related technology does not consider the influence of carrier phase, which will cause the rotation of the constellation diagram and make the signal unable to be demodulated. It is difficult to handle some cases of carrier phase mismatch. In addition, some algorithms often ignore the IQ imbalance phenomenon at the transmitter and are difficult to be applied to both the receiver and the transmitter. Therefore, the signal quality is low.

[0049] In view of this, an embodiment of the present disclosure provides a method for compensating carrier phase and IQ imbalance of a communication receiver, including:

[0050] A received signal of a communication receiver is sampled to obtain a received signal sequence, wherein the communication receiver includes a transmitter and a receiver, the receiver processes the transmitted signal from the transmitter to obtain a received signal, the received signal includes an I-branch received signal and a Q-branch received signal, and the transmitted signal includes an I-branch transmitted signal and a Q-branch transmitted signal; the expectation and covariance matrices of the received signal sequence are calculated, and a likelihood function corresponding to the received signal sequence is constructed based on the expectation and covariance matrices; the logarithmic function of the likelihood function is differentiated to obtain a group of estimation equations corresponding to multiple parameters to be estimated, wherein the multiple parameters to be estimated include a carrier phase parameter, a receiving end gain imbalance parameter, a receiving end phase imbalance parameter, a transmitting end gain imbalance parameter, and a transmitting end phase imbalance parameter; the estimation equation group is iteratively solved according to a predetermined number of iterations to obtain multiple target estimation parameters corresponding to the multiple parameters to be estimated; the received signal sequence is compensated based on the target estimation parameters to obtain a target signal sequence.

[0051] Figure 1 The flowchart of the method for compensating for carrier phase and IQ imbalance of a communication receiver according to an embodiment of the present disclosure is schematically shown.

[0052] like Figure 1 As shown, the method 100 includes operations S110 to S150.

[0053] In operation S110, a received signal of a communication receiver is sampled to obtain a received signal sequence.

[0054] In operation S120, the expectation and covariance matrices of the received signal sequence are calculated, and a likelihood function corresponding to the received signal sequence is constructed according to the expectation and covariance matrices.

[0055] In operation S130 , a logarithmic function of the likelihood function is derived to obtain a set of estimation equations corresponding to a plurality of parameters to be estimated.

[0056] In operation S140 , the estimation equations are iteratively solved according to a predetermined number of iterations to obtain a plurality of target estimation parameters corresponding to the plurality of parameters to be estimated.

[0057] In operation S150, the received signal sequence is compensated according to the target estimation parameter to obtain a target signal sequence.

[0058] According to an embodiment of the present disclosure, the received signal sequence consists of L sampling points, k∈L.

[0059] According to an embodiment of the present disclosure, the communication receiver includes a transmitting end and a receiving end. The receiving end processes the transmitting signal from the transmitting end to obtain a receiving signal. The receiving signal includes an I-branch receiving signal and a Q-branch receiving signal. The transmitting signal includes an I-branch transmitting signal and a Q-branch transmitting signal.

[0060] In order to better understand the signal transmission process in the communication receiver, the following will be Figure 1 Simulate the signal transmission process. In practical applications, the digital processing system of the communication receiver can be based on Figure 1 The signal transmission model shown processes the signal.

[0061] Figure 2 The figure schematically shows an architecture diagram of a signal transmission model according to an embodiment of the present disclosure.

[0062] like Figure 2 As shown, after the signal is input into the transmission model, it is divided into I branch transmission signals at the transmitting end ( ) and Q split transmission signal ( ), the two transmission signals are multiplied by different carrier signals and then added together to convert the zero intermediate frequency input signal to a radio frequency signal, which is then transmitted to the receiving end after the noise signal is introduced. At the receiving end, the two received signals are multiplied by different carrier signals and then added together, and the radio frequency signal is down-converted to a zero intermediate frequency output signal through a low-pass filter. = ±1, =±1.

[0063] Among them, for , the carrier signal multiplied in the multiplier is , is the carrier frequency; for , the carrier signal multiplied in the multiplier is , is the phase imbalance parameter at the transmitter, is the transmitter gain imbalance parameter; for the I branch receiving signal, the carrier signal multiplied in the multiplier is , is the carrier phase; for the Q branch receiving signal, the carrier signal multiplied in the multiplier is , is the gain imbalance parameter at the receiving end, is the phase imbalance parameter at the receiving end.

[0064] According to an embodiment of the present disclosure, it is expected to reflect the average state of the received signal, and the covariance matrix is ​​used to reflect the correlation of each component in the received signal sequence.

[0065] According to an embodiment of the present disclosure, the multiple parameters to be estimated include a carrier phase parameter, a receiving end gain imbalance parameter, a receiving end phase imbalance parameter, a transmitting end gain imbalance parameter, and a transmitting end phase imbalance parameter. The parameter to be estimated u can be expressed as the following formula (1).

[0066] (1)

[0067] in, is the carrier phase parameter, =40°. is the gain imbalance parameter at the receiving end, is the phase imbalance parameter at the receiving end, is the transmitter gain imbalance parameter, is the phase imbalance parameter at the transmitter, = =0.9, = =5°.

[0068] According to embodiments of the present disclosure, an iterative algorithm, such as the Newton-Raphson method, can be used to solve the likelihood function. Starting from initial estimates of multiple parameters to be estimated, the target estimated parameters are gradually approximated to their true values ​​through iteration. The predetermined number of iterations is a pre-set convergence condition.

[0069] According to an embodiment of the present disclosure, the received signal sequence is compensated according to the target estimation parameters to adjust the carrier phase parameters, the receiving end gain imbalance parameters, the receiving end phase imbalance parameters, the transmitting end gain imbalance parameters and the transmitting end phase imbalance parameters to restore to the target signal sequence.

[0070] Figure 3a The figure schematically shows a constellation simulation diagram of a received signal sequence before compensation according to an embodiment of the present disclosure.

[0071] Figure 3b The constellation simulation diagram of the compensated received signal sequence according to an embodiment of the present disclosure is schematically shown.

[0072] like Figure 3a and Figure 3b As shown in the figure, the horizontal axis is the real part of the signal, that is, the signal received by the I branch, and the vertical axis is the imaginary part of the signal, that is, the signal received by the Q branch. A comparison shows that before compensation, the constellation diagram is rotated and stretched due to the influence of the carrier phase, making it difficult to correctly demodulate the signal. After compensation, the rotation and stretching are corrected.

[0073] According to an embodiment of the present disclosure, a likelihood function corresponding to the received signal sequence is constructed by the expectation and covariance matrix of the received signal sequence, the likelihood function is differentiated to obtain a group of estimation equations, and the group of estimation equations is iteratively solved to obtain estimated values ​​of the carrier phase parameters, the receiving end gain imbalance parameters, the receiving end phase imbalance parameters, the transmitting end gain imbalance parameters and the transmitting end phase imbalance parameters, namely the target estimation parameters, and then the received signal sequence is compensated according to the target estimation parameters. Since the likelihood function is used to accurately estimate the parameters to be estimated, the influence of the carrier phase and the imbalance of the transmitting end can be considered at the same time, and multiple parameters to be estimated can be separately estimated and compensated according to actual needs, which effectively improves the accuracy of the estimation and thus improves the signal quality after compensation.

[0074] According to an embodiment of the present disclosure, the expression of the received signal sequence is as follows: Formula (2).

[0075] (2)

[0076] in, To receive the signal, I branch receives the signal, The Q branch receives the signal. is the transmission matrix, I is the branch transmission signal, For Q split transmission signal, is the noise signal of the I branch, is the noise signal of the Q branch.

[0077] According to an embodiment of the present disclosure, the noise signal of the I branch It can be expressed as the following formula (3).

[0078] (3)

[0079] in, The mean is 0 and the variance is Gaussian white noise.

[0080] According to an embodiment of the present disclosure, the noise signal of the Q branch It can be expressed as the following formula (4).

[0081] (4)

[0082] in, The mean is 0 and the variance is The other end is Gaussian white noise.

[0083] According to the embodiment of the present disclosure, by comparing formula (2) and formula (3), it can be seen that the noise signals received by the I branch and the Q branch are different, but correlated with each other, and the correlation coefficient is affected by the phase imbalance parameter of the receiving end. and receiver gain imbalance parameters Influence.

[0084] According to an embodiment of the present disclosure, the transmission matrix It can be expressed as the following formula (5).

[0085] (5)

[0086] According to an embodiment of the present disclosure, the expected value of the received signal sequence is It can be expressed as the following formula (6).

[0087] (6)

[0088] According to an embodiment of the present disclosure, based on the above formulas (2) and (6), the received signal sequence can also be expressed as the following formula (7).

[0089] (7)

[0090] in, are two-way noise signals, and .

[0091] According to an embodiment of the present disclosure, the covariance matrix of the received signal sequence can be expressed as the following formula (8).

[0092] (8)

[0093] According to an embodiment of the present disclosure, the likelihood function It can be expressed as the following formula (9).

[0094] (9)

[0095] Where T is the matrix transpose symbol.

[0096] According to an embodiment of the present disclosure, by substituting the above formula (6) and formula (8) into formula (9), the following formula (10) can be obtained.

[0097] (10)

[0098] in, Indicates continuous multiplication, Represents the relevant parameters. The above formula (10) is based on the assumption of Gaussian distribution.

[0099] According to the embodiment of the present disclosure, the relevant parameters It can be expressed as the following formula (11).

[0100] (11)

[0101] in, I branch receives the signal expectations, Split the received signal for Q expectations.

[0102] According to an embodiment of the present disclosure, the likelihood function provides the probability of a received signal sequence occurring under the parameters to be estimated, which is used to evaluate the performance of the entire communication receiver system, and can jointly estimate multiple parameters to be estimated related to IQ imbalance, with a certain degree of robustness.

[0103] According to an embodiment of the present disclosure, the estimation equation group includes equations corresponding to multiple parameters to be estimated, and the logarithmic function of the likelihood function is differentiated to obtain the estimation equation group corresponding to the multiple parameters to be estimated, including: calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the carrier phase parameter to obtain a first equation corresponding to the carrier phase parameter; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the receiving end gain imbalance parameter to obtain a second equation corresponding to the receiving end gain imbalance parameter; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the receiving end phase imbalance parameter to obtain a third equation corresponding to the receiving end phase imbalance parameter; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the transmitting end gain imbalance parameter to obtain a fourth equation corresponding to the transmitting end gain imbalance parameter; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the transmitting end phase imbalance parameter to obtain a fifth equation corresponding to the transmitting end phase imbalance parameter.

[0104] According to an embodiment of the present disclosure, the process of deriving the logarithmic function of the likelihood function can be expressed as the following formula (12).

[0105] (12)

[0106] in, represents the system of estimated equations, i = 1, 2, 3, 4, 5. When i = 1, it corresponds to the first equation; when i = 2, it corresponds to the second equation; when i = 3, it corresponds to the third equation; when i = 4, it corresponds to the fourth equation; and when i = 5, it corresponds to the fifth equation.

[0107] According to an embodiment of the present disclosure, the first equation It can be expressed as the following formula (13).

[0108] (13)

[0109] in, represents the first coefficient of the first equation, which can be expressed as the following formula (14); The second coefficient of the first equation can be expressed as follows (15): The third coefficient of the first equation can be expressed as follows (16): The fourth coefficient of the first equation can be expressed as the following formula (17).

[0110] (14)

[0111] (15)

[0112] (16)

[0113] (17)

[0114] According to an embodiment of the present disclosure, the second equation It can be expressed as the following formula (18).

[0115] (18)

[0116] in, is the first coefficient of the second equation, which can be expressed as the following formula (19); is the second coefficient of the second equation, which can be expressed as the following formula (20).

[0117] (19)

[0118] (20)

[0119] According to an embodiment of the present disclosure, the third program It can be expressed as the following formula (21).

[0120] (twenty one)

[0121] in, is the first coefficient of the third equation, which can be expressed as the following formula (22).

[0122] (twenty two)

[0123] According to an embodiment of the present disclosure, the fourth equation It can be expressed as the following formula (23).

[0124] (twenty three)

[0125] in, The first coefficient of the fourth equation can be expressed as follows (24): The second coefficient of the fourth equation can be expressed as the following formula (25).

[0126] (twenty four)

[0127] (25)

[0128] According to an embodiment of the present disclosure, the fifth equation It can be expressed as the following formula (26).

[0129] (26)

[0130] According to the embodiments of the present disclosure, solving the estimation equations by equalizing the estimation equations to zero can obtain estimated values ​​of the parameters to be estimated, but there is no closed-form solution for nonlinear equations, so other methods are needed to solve the nonlinear estimation equations.

[0131] According to an embodiment of the present disclosure, by calculating the first-order derivative of the logarithmic function of the likelihood function, a group of estimation equations related to the carrier phase parameter, the receiving end gain imbalance parameter, the receiving end phase imbalance parameter, the transmitting end gain imbalance parameter and the transmitting end phase imbalance parameter can be obtained to achieve maximum likelihood estimation of the above parameters.

[0132] According to an embodiment of the present disclosure, iteratively solving a system of estimation equations according to a predetermined number of iterations to obtain target estimated parameters includes: performing partial derivative processing on each equation in the system of estimation equations to obtain a Jacobian matrix; and performing Newton iteration processing on the system of estimation equations according to the Jacobian matrix corresponding to the predetermined number of iterations to obtain the target estimated parameters. The predetermined number of iterations may be 3 or 4.

[0133] According to an embodiment of the present disclosure, the Jacobian matrix It can be expressed as the following formula (27)

[0134] (27)

[0135] According to an embodiment of the present disclosure, the Newton iteration process can be expressed as the following formula (28):

[0136] (28)

[0137] Wherein, n is the predetermined number of iterations.

[0138] According to an embodiment of the present disclosure, the target estimation parameters include carrier phase estimation parameters, receiving end gain imbalance estimation parameters, receiving end phase imbalance estimation parameters, transmitting end gain imbalance estimation parameters and transmitting end phase imbalance estimation parameters, and the target signal sequence can be expressed as the following formula (29).

[0139] (29)

[0140] in, represents the target signal sequence, represents the I branch compensation signal corresponding to the I branch receiving signal, represents the Q branch compensation signal corresponding to the Q branch receiving signal, represents the inverse transmission matrix, represents the carrier phase estimation parameter, represents the receiver gain imbalance estimation parameter, represents the receiver phase imbalance estimation parameter, represents the transmitter gain imbalance estimation parameter, represents the transmitter phase imbalance estimation parameter, I branch receives the signal, Splits the received signal for Q.

[0141] According to an embodiment of the present disclosure, the target signal sequence of the above formula (29) ignores the noise signal.

[0142] According to an embodiment of the present disclosure, the target estimation parameter It can be expressed as the following formula (30)

[0143] (30)

[0144] According to an embodiment of the present disclosure, in order to better reflect the accuracy of the above compensation method, each target estimation parameter can be measured by calculating the Cramer-Rao lower bound. The specific implementation is as follows.

[0145] According to an embodiment of the present disclosure, by calculating the second-order partial derivative of the logarithmic function of the likelihood function, the information matrix of the received signal sequence shown in the following formula (31) can be obtained: , the information matrix consists of d row vectors, h column vectors, and d, h∈{1 2 3 4 5}.

[0146] (31)

[0147] in, is the information matrix vector of the dth row and hth column, which can be expressed as the following formula (32).

[0148] (32)

[0149] in, , tr represents the trace of the matrix.

[0150] According to an embodiment of the present disclosure, for each vector I in the information matrix 11 ~I 55 Solving it, we can get the following formula (33).

[0151] (33)

[0152] According to an embodiment of the present disclosure, the Cramer-Rao lower bound corresponding to each parameter to be estimated can be obtained by the above formula (33), which can be expressed as the following formula (34).

[0153] (34)

[0154] According to an embodiment of the present disclosure, represents the Cramer-Rao lower bound, The Cramer-Rao lower bound expressed in formula (34) above indicates the minimum variance that the target estimated parameter can achieve given the parameters to be estimated.

[0155] According to an embodiment of the present disclosure, the mean square error (MSE) of the parameter to be estimated can be expressed as the following formula (35).

[0156] (35)

[0157] Figure 4 A curve diagram schematically illustrates the impact of a change in a phase imbalance parameter at a receiving end on the mean square error and the Cramer-Rao lower bound according to an embodiment of the present disclosure.

[0158] like Figure 4 As shown, , , , , . From -20° to 20°. The mean square error and Cramer-Rao lower bound of each parameter to be estimated will change with However, the mean square error is always close to the Cramer-Rao lower bound, which reflects that the estimation of the compensation method is close to the effective theoretical value and has a high estimation accuracy.

[0159] Figure 5 A curve diagram schematically illustrates the effect of a change in the length of a received signal sequence on the mean square error and the Cramer-Rao lower bound according to an embodiment of the present disclosure.

[0160] like Figure 5 As shown, , , , L varies from 500 to 10000. The mean square error and Cramer-Rao lower bound of each parameter to be estimated will change with the length of the sequence, but the mean square error and Cramer-Rao lower bound always remain relatively close. In addition, when the above parameters to be estimated remain unchanged and the signal-to-noise ratio is constant, the estimation accuracy improves with the increase of sequence length.

[0161] Figure 6 A curve diagram schematically illustrates the impact of carrier phase changes on mean square error and Cramer-Rao lower bound according to an embodiment of the present disclosure.

[0162] like Figure 6 As shown, , , , . From -180° to 180°. The mean square error and Cramer-Rao lower bound of each parameter to be estimated will change with , but the mean square error always remains relatively close to the Cramer-Rao lower bound, which reflects that the estimation of the compensation method is close to the effective theoretical value and has a high estimation accuracy.

[0163] Figure 7 A curve diagram schematically illustrates the impact of a change in a gain imbalance parameter at the receiving end on the mean square error and the Cramer-Rao lower bound according to an embodiment of the present disclosure.

[0164] like Figure 7 As shown, , , , . From 0.6 to 1.4. The mean square error and Cramer-Rao lower bound of each parameter to be estimated will change with , but the mean square error always remains relatively close to the Cramer-Rao lower bound, which reflects that the estimation of the compensation method is close to the effective theoretical value and has a high estimation accuracy.

[0165] Figure 8 A curve diagram schematically illustrates the effect of a change in the signal-to-noise ratio on the mean square error and the Cramer-Rao lower bound according to an embodiment of the present disclosure.

[0166] like Figure 8 As shown, , , , The signal-to-noise ratio (SNR) varies from 1dB to 20dB. The mean square error (MSE) and Cramer-Rao lower bound of each estimated parameter change with the SNR, but the MSE and Cramer-Rao lower bound always remain relatively close, indicating that the compensation method's estimates are close to the effective theoretical values ​​and have high estimation accuracy.

[0167] Figure 9 The figure schematically shows a block diagram of a device for compensating for carrier phase and IQ imbalance of a communication receiver according to an embodiment of the present disclosure.

[0168] like Figure 9 As shown, the compensation device 900 includes a sampling module 910 , a construction module 920 , a derivation module 930 , an iteration module 940 and a compensation module 950 .

[0169] The sampling module 910 is used to discretely sample the received signal of the communication receiver to obtain a received signal sequence, wherein the communication receiver includes a transmitting end and a receiving end, the receiving end processes the transmitted signal from the transmitting end to obtain a received signal, the received signal includes an I branch received signal and a Q branch received signal, and the transmitted signal includes an I branch transmitted signal and a Q branch transmitted signal.

[0170] The construction module 920 is configured to calculate the expectation and covariance matrix of the received signal sequence, and construct a likelihood function corresponding to the received signal sequence according to the expectation and covariance matrix.

[0171] A derivation module 930 is used to derive a logarithmic function of the likelihood function to obtain a set of estimation equations corresponding to multiple parameters to be estimated, wherein the multiple parameters to be estimated include a carrier phase parameter, a receiving end gain imbalance parameter, a receiving end phase imbalance parameter, a transmitting end gain imbalance parameter, and a transmitting end phase imbalance parameter.

[0172] The iteration module 940 is used to iteratively solve the estimation equation group according to a predetermined number of iterations to obtain multiple target estimation parameters corresponding to the multiple parameters to be estimated.

[0173] The compensation module 950 is configured to compensate the received signal sequence according to the target estimation parameter to obtain a target signal sequence.

[0174] According to the embodiments of the present invention, any number of modules, sub-modules, units, and sub-units, or at least part of the functions of any number of them, can be implemented in one module. According to the embodiments of the present invention, any one or more of the modules, sub-modules, units, and sub-units can be split into multiple modules for implementation. According to the embodiments of the present invention, any one or more of the modules, sub-modules, units, and sub-units can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application-specific integrated circuit (ASIC), or can be implemented by hardware or firmware in any other reasonable way of integrating or packaging the circuit, or can be implemented in any one of the three implementation methods of software, hardware, and firmware, or in any appropriate combination of any of them. Alternatively, according to the embodiments of the present invention, one or more of the modules, sub-modules, units, and sub-units can be at least partially implemented as a computer program module, which can perform the corresponding functions when the computer program module is executed.

[0175] For example, any number of the sampling module 910, the construction module 920, the derivation module 930, the iteration module 940, and the compensation module 950 can be combined into a single module / unit / sub-unit, or any one of these modules / units / sub-units can be split into multiple modules / units / sub-units. Alternatively, at least part of the functionality of one or more of these modules / units / sub-units can be combined with at least part of the functionality of other modules / units / sub-units and implemented in a single module / unit / sub-unit. According to an embodiment of the present disclosure, at least one of the sampling module 910, the construction module 920, the derivation module 930, the iteration module 940, and the compensation module 950 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented in hardware or firmware by any other reasonable means of circuit integration or packaging, or can be implemented in any one of the three implementation methods of software, hardware, and firmware, or any appropriate combination of any of these. Alternatively, at least one of the sampling module 910 , the construction module 920 , the derivation module 930 , the iteration module 940 , and the compensation module 950 may be at least partially implemented as a computer program module, which may perform corresponding functions when executed.

[0176] It should be noted that the compensation device part in the embodiment of the present disclosure corresponds to the compensation method part in the embodiment of the present disclosure. The description of the compensation device part specifically refers to the compensation method part and will not be repeated here.

[0177] Figure 10 The block diagram schematically shows an electronic device suitable for implementing a method for compensating a carrier phase and IQ imbalance for a communication receiver according to an embodiment of the present disclosure. Figure 10 The electronic device shown is only an example and should not limit the functions and scope of use of the embodiments of the present disclosure.

[0178] like Figure 10As shown, the electronic device 1000 according to an embodiment of the present disclosure includes a processor 1001, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage portion 1008 into a random access memory (RAM) 1003. The processor 1001 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 1001 may also include onboard memory for caching purposes. The processor 1001 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present disclosure.

[0179] Various programs and data required for the operation of the electronic device 1000 are stored in the RAM 1003. The processor 1001, the ROM 1002, and the RAM 1003 are connected to each other via a bus 1004. The processor 1001 performs various operations of the method flow according to the embodiment of the present disclosure by executing the programs in the ROM 1002 and / or the RAM 1003. It should be noted that the programs may also be stored in one or more memories other than the ROM 1002 and the RAM 1003. The processor 1001 may also perform various operations of the method flow according to the embodiment of the present disclosure by executing the programs stored in the one or more memories.

[0180] According to an embodiment of the present disclosure, electronic device 1000 may further include an input / output (I / O) interface 1005, which is also connected to bus 1004. Electronic device 1000 may also include one or more of the following components connected to I / O interface 1005: an input section 1006 including a keyboard, mouse, etc.; an output section 1007 including devices such as a cathode ray tube (CRT), liquid crystal display (LCD), and speakers; a storage section 1008 including a hard disk; and a communication section 1009 including a network interface card such as a LAN card or modem. Communication section 1009 performs communication processing via a network such as the Internet. A drive 1010 is also connected to I / O interface 1005 as needed. Removable media 1011, such as a magnetic disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed in drive 1010 as needed, so that computer programs read from the removable media can be installed into storage section 1008 as needed.

[0181] According to an embodiment of the present disclosure, the method flow according to an embodiment of the present disclosure can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program carried on a computer-readable storage medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 1009, and / or installed from the removable medium 1011. When the computer program is executed by the processor 1001, the above-mentioned functions defined in the system of the embodiment of the present disclosure are executed. According to an embodiment of the present disclosure, the system, equipment, device, module, unit, etc. described above can be implemented by a computer program module.

[0182] The present disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments, or may exist independently and not be incorporated into the device / apparatus / system. The computer-readable storage medium carries one or more programs, and when executed, implements the method according to the embodiments of the present disclosure.

[0183] According to embodiments of the present disclosure, a computer-readable storage medium may be a non-volatile computer-readable storage medium. Examples include, but are not limited to, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0184] For example, according to an embodiment of the present disclosure, the computer-readable storage medium may include the ROM 1002 and / or the RAM 1003 described above and / or one or more memories other than the ROM 1002 and the RAM 1003 .

[0185] An embodiment of the present disclosure also includes a computer program product, which includes a computer program containing program code for executing the method provided by the embodiment of the present disclosure. When the computer program product is run on an electronic device, the program code is used to enable the electronic device to implement the carrier phase and IQ imbalance compensation method for a communication receiver provided by the embodiment of the present disclosure.

[0186] When the computer program is executed by the processor 1001, the above functions defined in the system / device of the embodiment of the present disclosure are performed. According to the embodiment of the present disclosure, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0187] In one embodiment, the computer program may be stored on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may be transmitted and distributed in the form of a signal on a network medium, downloaded and installed via the communication portion 1009, and / or installed from the removable medium 1011. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0188] According to an embodiment of the present disclosure, the program code for executing the computer program provided by the embodiment of the present disclosure can be written in any combination of one or more programming languages. Specifically, these computer programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C" or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (for example, using an Internet service provider to connect via the Internet).

[0189] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or part of the code, which contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the boxes can also occur in an order different from that marked in the accompanying drawings. For example, two boxes shown in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, as well as the combination of boxes in the block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified functions or operations, or can be implemented using a combination of dedicated hardware and computer instructions. It will be understood by those skilled in the art that the features described in the various embodiments of the present disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments of the present disclosure may be combined and / or coupled in various ways, and all of these combinations and / or couplings fall within the scope of the present disclosure.

[0190] The above describes the embodiments of the present disclosure. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be advantageously used in combination. Without departing from the scope of the present disclosure, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A method for compensating carrier phase and IQ imbalance in a communication receiver, characterized in that: include: Sampling a received signal of a communication receiver to obtain a received signal sequence, wherein the communication receiver includes a transmitting end and a receiving end, the receiving end processes a transmit signal from the transmitting end to obtain the received signal, the received signal includes an I-branch received signal and a Q-branch received signal, and the transmit signal includes an I-branch transmit signal and a Q-branch transmit signal; Calculating the expectation and covariance matrix of the received signal sequence, and constructing a likelihood function corresponding to the received signal sequence based on the expectation and the covariance matrix, wherein the expression of the likelihood function is: ； in, represents the likelihood function, k represents the sampling point, represents the covariance matrix, represents the received signal, express said expectations; Deriving a logarithmic function of the likelihood function to obtain a set of estimation equations corresponding to a plurality of parameters to be estimated, wherein the plurality of parameters to be estimated include a carrier phase parameter, a receiving end gain imbalance parameter, a receiving end phase imbalance parameter, a transmitting end gain imbalance parameter, and a transmitting end phase imbalance parameter; Iteratively solving the estimation equation group according to a predetermined number of iterations to obtain a plurality of target estimation parameters corresponding to the plurality of parameters to be estimated; The received signal sequence is compensated according to the target estimation parameter to obtain a target signal sequence.

2. The method according to claim 1, characterized in that The iteratively solving the estimation equations according to a predetermined number of iterations to obtain target estimation parameters includes: Performing partial derivative processing on each equation in the estimation equation group to obtain a Jacobian matrix; According to the Jacobian matrix, Newton iteration processing corresponding to the predetermined number of iterations is performed on the estimation equation group to obtain target estimation parameters.

3. The method according to claim 2, characterized in that The predetermined number of iterations includes 3 or 4.

4. The method according to claim 1, wherein The expression of the received signal sequence is: in, is the received signal, The I branch receives a signal, The Q branch receives the signal, is the transmission matrix, is the carrier phase parameter, is the receiving end gain imbalance parameter, is the receiving end phase imbalance parameter, is the transmitter gain imbalance parameter, is the transmitter phase imbalance parameter, The I branch transmits a signal, For the Q branch transmission signal, is the noise signal of the I branch, is the noise signal of the Q branch.

5. The method according to claim 4, characterized in that The expression of the transmission matrix is: 。 6. The method according to claim 1, characterized in that The target estimation parameters include carrier phase estimation parameters, receiving end gain imbalance estimation parameters, receiving end phase imbalance estimation parameters, transmitting end gain imbalance estimation parameters and transmitting end phase imbalance estimation parameters. The target signal sequence is expressed as: in, represents the target signal sequence, represents an I-branch compensation signal corresponding to the I-branch received signal, represents a Q branch compensation signal corresponding to the Q branch received signal, represents the inverse transmission matrix, represents the carrier phase estimation parameter, represents the receiving end gain imbalance estimation parameter, represents the receiving end phase imbalance estimation parameter, represents the transmitter gain imbalance estimation parameter, represents the transmitter phase imbalance estimation parameter, I branch receives the signal, Splits the received signal for Q.

7. The method according to claim 1, characterized in that The estimation equation group includes a plurality of equations corresponding to the plurality of parameters to be estimated, and the derivation of the logarithmic function of the likelihood function to obtain the estimation equation group corresponding to the plurality of parameters to be estimated includes: Calculating a first-order derivative of a logarithmic function of the likelihood function with respect to the carrier phase parameter to obtain a first equation corresponding to the carrier phase parameter; Calculating a first-order derivative of a logarithmic function of the likelihood function with respect to the receiving-end gain imbalance parameter to obtain a second equation corresponding to the receiving-end gain imbalance parameter; Calculating a first-order derivative of a logarithmic function of the likelihood function with respect to the receiving-end phase imbalance parameter to obtain a third equation corresponding to the receiving-end phase imbalance parameter; Calculating a first-order derivative of a logarithmic function of the likelihood function with respect to the transmitter gain imbalance parameter to obtain a fourth equation corresponding to the transmitter gain imbalance parameter; A first-order derivative of a logarithmic function of the likelihood function with respect to the transmit-end phase imbalance parameter is calculated to obtain a fifth equation corresponding to the transmit-end phase imbalance parameter.

8. A carrier phase and IQ imbalance compensation device for a communication receiver, characterized in that: include: a sampling module, configured to sample a received signal of a communication receiver to obtain a received signal sequence, wherein the communication receiver includes a transmitting end and a receiving end, the receiving end processes a transmit signal from the transmitting end to obtain the received signal, the received signal includes an I-branch received signal and a Q-branch received signal, and the transmit signal includes an I-branch transmit signal and a Q-branch transmit signal; A construction module is configured to calculate the expectation and covariance matrix of the received signal sequence, and construct a likelihood function corresponding to the received signal sequence based on the expectation and the covariance matrix, wherein the expression of the likelihood function is: ； in, represents the likelihood function, k represents the sampling point, represents the covariance matrix, represents the received signal, express said expectations; a derivation module, configured to derive a logarithmic function of the likelihood function to obtain a set of estimation equations corresponding to a plurality of parameters to be estimated, wherein the plurality of parameters to be estimated include a carrier phase parameter, a receiving end gain imbalance parameter, a receiving end phase imbalance parameter, a transmitting end gain imbalance parameter, and a transmitting end phase imbalance parameter; An iterative module, configured to iteratively solve the estimation equations according to a predetermined number of iterations to obtain a plurality of target estimation parameters corresponding to the plurality of parameters to be estimated; The compensation module is used to compensate the received signal sequence according to the target estimation parameter to obtain a target signal sequence.

9. An electronic device comprising: one or more processors; a memory for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors are enabled to implement the method according to any one of claims 1 to 7.

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