Compensation method, device and equipment for carrier phase and IQ imbalance of communication receiver

Abstract

The invention provides a carrier phase and IQ imbalance compensation method, device and equipment for a communication receiver, which can be applied to the technical field of communication signal processing. The method comprises the steps that received signals of a communication receiver are sampled to obtain a received signal sequence, the communication receiver comprises a transmitting end and a receiving end, and the receiving end processes the transmitted signals from the transmitting end to obtain the received signals; calculating an expectation and covariance matrix of the received signal sequence, and constructing a likelihood function corresponding to the received signal sequence according to the expectation and covariance matrix; deriving a logarithmic function of the likelihood function to obtain an estimation equation set corresponding to the plurality of to-be-estimated parameters; performing iterative solution on the estimation equation set according to a predetermined number of iterations to obtain a plurality of target estimation parameters corresponding to the plurality of to-be-estimated parameters; and compensating the received signal sequence according to the target estimation parameter to obtain a target signal sequence.

Description

Technical Field

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

[0002] The zero-IF receiver has a simple architecture and is currently widely used in the field of communication signal processing. However, due to the imperfection of the hardware, the I (in-phase) Q (quadrature) imbalance phenomenon exists, that is, the gain and phase of the I branch and Q branch signals are not completely matched. The IQ imbalance will cause the Q branch signal to deviate, thereby affecting the deviation of the signal, and will cause image interference, reducing the signal-to-noise ratio of the signal.

[0003] In the process of implementing the concept of the present disclosure, the inventors found that it is difficult to take into account the influence of the carrier phase in the compensation for IQ imbalance in the related art 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 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] The received signal of the 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 according to the expectation and covariance matrices; the logarithmic function of the likelihood function is derived to obtain an estimation equation group 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 according to 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; based on the Jacobian matrix, performing Newton iteration processing on the estimation equation group corresponding to the predetermined number of iterations to obtain the 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 is the receiving signal of the branch, 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 transmission signal of the branch, The Q branch transmits the 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, and 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 estimated parameter of gain imbalance at the receiving end, represents the receiving end phase imbalance estimation parameter, represents the transmitter gain imbalance estimation parameter, represents the estimated parameter of the phase imbalance at the transmitter, I is the receiving signal of the branch, The received signal is split into two parts:

[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 the 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 gain imbalance parameter of the receiving end to obtain the second equation corresponding to the gain imbalance parameter of the receiving end; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the phase imbalance parameter of the receiving end to obtain the third equation corresponding to the phase imbalance parameter of the receiving end; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the gain imbalance parameter of the transmitting end to obtain the fourth equation corresponding to the gain imbalance parameter of the transmitting end; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the phase imbalance parameter of the transmitting end to obtain the fifth equation corresponding to the phase imbalance parameter of the transmitting end.

[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 is used 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 receiving signal and a Q branch receiving signal, and the transmitted signal includes an I branch transmitting signal and a Q branch transmitting signal;

[0023] A construction module is used 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;

[0024] A derivation module, used for derivation of the logarithmic function of the likelihood function to obtain a group 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 iteration module, used for 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;

[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 using the expectation and covariance matrix of the received signal sequence, the likelihood function is differentiated to obtain a group of estimation equations, the group of estimation equations is iteratively solved to obtain estimated values ​​of carrier phase parameters, receiving end gain imbalance parameters, receiving end phase imbalance parameters, transmitting end gain imbalance parameters and transmitting end phase imbalance parameters, i.e., 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 the carrier phase and IQ imbalance of a communication receiver according to an embodiment of the present disclosure is schematically shown.

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

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

[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 shows the influence of the change of the phase 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.

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

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

[0040] Figure 7 A curve diagram schematically illustrates the influence of a change in a gain imbalance parameter at a receiving end on a mean square error and a 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] Fig. 9 A block diagram of a carrier phase and IQ imbalance compensation device for a communication receiver according to an embodiment of the present disclosure is schematically shown.

[0043] Fig.10 A block diagram of 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 is schematically shown. 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 exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, 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 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 existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0046] All terms (including technical and scientific terms) used herein 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 using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression 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] In the related art, the compensation methods for IQ imbalance 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 apply 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 a carrier phase and IQ imbalance of a communication receiver, comprising:

[0050] The received signal of the 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 according to the expectation and covariance matrices; the logarithmic function of the likelihood function is derived to obtain an estimation equation group 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 according to the target estimation parameters to obtain a target signal sequence.

[0051] Figure 1 The flowchart of the method for compensating the 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 matrix of the received signal sequence is calculated, and a likelihood function corresponding to the received signal sequence is constructed according to the expectation and covariance matrix.

[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 equation group is 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 is composed of L sampling points, k∈L.

[0059] According to an embodiment of the present disclosure, a communication receiver includes a transmitting end and a receiving end. The receiving end processes a 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 transmission process of the signal 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 schematic diagram 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 transmit signal ( ), the two transmission signals are multiplied by different carrier signals and then added to convert the zero intermediate frequency input signal to a radio frequency signal, and then the noise signal is introduced and transmitted to the receiving end. At the receiving end, the two receiving signals are multiplied by different carrier signals and then added, and the radio frequency signal is down-converted to a zero intermediate frequency output signal through a low-pass filter. Among them, = ±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 gain imbalance parameter at the transmitting end; 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 be used 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 an embodiment of the present disclosure, an iterative algorithm such as the Newton-Raphson method can be used to solve the likelihood function, starting from the initial estimated values ​​of multiple parameters to be estimated, and gradually approaching the true parameter values ​​through iteration to obtain the target estimated parameters. 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 constellation simulation diagram of the received signal sequence before compensation according to an embodiment of the present disclosure is schematically shown.

[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 I branch receiving signal, and the vertical axis is the imaginary part of the signal, that is, the Q branch receiving signal. By comparison, it can be seen that before compensation, due to the influence of the carrier phase, the constellation diagram is rotated and stretched, which makes it difficult to demodulate the signal correctly. 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 using the expectation and covariance matrix of the received signal sequence, the likelihood function is differentiated to obtain a group of estimation equations, the group of estimation equations is iteratively solved to obtain estimated values ​​of carrier phase parameters, receiving end gain imbalance parameters, receiving end phase imbalance parameters, transmitting end gain imbalance parameters and transmitting end phase imbalance parameters, i.e., 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 is the receiving signal of the branch, The Q branch receives the signal, is the transmission matrix, I is the transmission signal of the branch, The Q branch transmits the 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 the 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 gain imbalance parameter of the receiving end to obtain the second equation corresponding to the gain imbalance parameter of the receiving end; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the phase imbalance parameter of the receiving end to obtain the third equation corresponding to the phase imbalance parameter of the receiving end; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the gain imbalance parameter of the transmitting end to obtain the fourth equation corresponding to the gain imbalance parameter of the transmitting end; calculating the first-order derivative of the logarithmic function of the likelihood function with respect to the phase imbalance parameter of the transmitting end to obtain the fifth equation corresponding to the phase imbalance parameter of the transmitting end.

[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 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; 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, The first coefficient of the first equation can be expressed as follows (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 party 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 the estimated values ​​of the parameters to be estimated, but there is no closed solution for the 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, 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 corresponding to the predetermined number of iterations on the estimation equation group according to the Jacobian matrix to obtain the target estimation parameters. The predetermined number of iterations includes 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 estimated parameter of gain imbalance at the receiving end, represents the receiving end phase imbalance estimation parameter, represents the transmitter gain imbalance estimation parameter, represents the estimated parameter of the phase imbalance at the transmitter, I is the receiving signal of the branch, The received signal is split into two parts:

[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 d-th row and the h-th 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 the above formula (34) 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 shows the influence of the change of the phase 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.

[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 The mean square error changes with the change, but it always remains close to the Cramer-Rao lower bound, which reflects that the estimation of the compensation method mentioned above is close to the effective theoretical value and has a higher estimation accuracy.

[0159] Figure 5 A curve diagram schematically illustrates the effect of a change in the length of a received signal sequence on a mean square error and a 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 sequence length, but the mean square error and Cramer-Rao lower bound always remain relatively close, and when the above parameters to be estimated remain unchanged and the signal-to-noise ratio is constant, the estimation accuracy increases with the increase of sequence length.

[0161] Figure 6 A curve diagram schematically illustrates the effect of a change in carrier phase on a mean square error and a 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 is always 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 higher estimation accuracy.

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

[0164] like Figure 7 As shown, , , , . The mean square error and Cramer-Rao lower bound of each parameter to be estimated will change with , but the mean square error is always 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 higher 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 1 dB to 20 dB. The mean square error and Cramer-Rao lower bound of each parameter to be estimated will change with the change of SNR, but the mean square error and Cramer-Rao lower bound always remain relatively close, which reflects that the estimation of the above compensation method is close to the effective theoretical value and has a high estimation accuracy.

[0167] Fig. 9 A block diagram of a carrier phase and IQ imbalance compensation device for a communication receiver according to an embodiment of the present disclosure is schematically shown.

[0168] like Fig. 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 used 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] The derivation module 930 is used to derive the 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 used to compensate the received signal sequence according to the target estimation parameter to obtain the target signal sequence.

[0174] According to the embodiments of the present invention, any one or more of the modules, submodules, units, and subunits, or at least part of the functions of any one of them can be implemented in one module. According to the embodiments of the present invention, any one or more of the modules, submodules, units, and subunits can be split into multiple modules for implementation. According to the embodiments of the present invention, any one or more of the modules, submodules, units, and subunits can be at least partially implemented as hardware circuits, such as field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), systems on chips, systems on substrates, systems on packages, application specific integrated circuits (ASICs), or can be implemented by hardware or firmware in any other reasonable way of integrating or packaging circuits, 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, submodules, units, and subunits can be at least partially implemented as computer program modules, and when the computer program modules are run, the corresponding functions can be performed.

[0175] For example, any multiple 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 in one module / unit / sub-unit for implementation, or any one of the modules / units / sub-units can be split into multiple modules / units / sub-units. Alternatively, at least part of the functions of one or more of these modules / units / sub-units can be combined with at least part of the functions of other modules / units / sub-units and implemented in one 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 by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation methods of software, hardware, and firmware, or in any appropriate combination of any of them. 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, and when the computer program module is executed, the corresponding function may be performed.

[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, which will not be repeated here.

[0177] Fig.10 A block diagram of 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 is schematically shown. Fig.10 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0178] like Fig.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 part 1008 to a random access memory (RAM) 1003. The processor 1001 may include, for example, a general-purpose microprocessor (such as a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (for example, an application-specific integrated circuit (ASIC)), etc. The processor 1001 may also include an 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] In RAM 1003, various programs and data required for the operation of electronic device 1000 are stored. Processor 1001, ROM 1002 and RAM 1003 are connected to each other via bus 1004. Processor 1001 performs various operations of the method flow according to the embodiment of the present disclosure by executing the program in ROM 1002 and / or RAM 1003. It should be noted that the program can also be stored in one or more memories other than ROM 1002 and RAM 1003. Processor 1001 can also perform various operations of the method flow according to the embodiment of the present disclosure by executing the program stored in the one or more memories.

[0180] According to an embodiment of the present disclosure, the electronic device 1000 may further include an input / output (I / O) interface 1005, which is also connected to the bus 1004. The electronic device 1000 may further include one or more of the following components connected to the input / output (I / O) interface 1005: an input portion 1006 including a keyboard, a mouse, etc.; an output portion 1007 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 1008 including a hard disk, etc.; and a communication portion 1009 including a network interface card such as a LAN card, a modem, etc. The communication portion 1009 performs communication processing via a network such as the Internet. A drive 1010 is also connected to the input / output (I / O) interface 1005 as needed. A removable medium 1011, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 1010 as needed, so that a computer program read therefrom is installed into the storage portion 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 contains 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 without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present disclosure is implemented.

[0183] According to an embodiment of the present disclosure, the computer-readable storage medium may be a non-volatile computer-readable storage medium. For example, it may include, but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an 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 may be used by or in combination 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, and the computer program contains a program code for executing the method provided by the embodiment of the present disclosure. When the computer program product runs 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 executed. 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 rely on tangible storage media such as optical storage devices, magnetic storage devices, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a network medium, and downloaded and installed through the communication part 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, etc., or any suitable combination of the above.

[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 computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of 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 through the Internet).

[0189] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, 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 may represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box may also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented 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, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions. It can be understood by those skilled in the art that the features recorded in the various embodiments of the present disclosure can be combined and / or combined in a variety of ways, even if such a combination or combination is not explicitly recorded in the present disclosure. In particular, without departing from the spirit and teaching of the present disclosure, the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0190] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of 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 transmitted 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 transmitted signal includes an I-branch transmitted signal and a Q-branch transmitted signal; Calculating the expectation and covariance matrix of the received signal sequence, and constructing a likelihood function corresponding to the received signal sequence according to the expectation and the covariance matrix; Deriving the logarithmic function of the likelihood function to obtain a group 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 equation group 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, the estimation equation group is subjected to Newton iteration processing corresponding to the predetermined number of iterations 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, characterized in that: 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 the stated expectation.

5. The method according to claim 1, characterized in that The expression of the received signal sequence is: in, For 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 transmitting end phase imbalance parameter, The I branch transmits a signal, for the Q branch to transmit a signal, is the noise signal of the I branch, is the noise signal of the Q branch.

6. The method according to claim 5, characterized in that The expression of the transmission matrix is: 。 7. 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, and 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 is the receiving signal of the branch, The received signal is split into two parts:

8. 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 logarithmic function of the likelihood function is derived to obtain the estimation equation group corresponding to the plurality of parameters to be estimated, including: 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 the 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.

9. A carrier phase and IQ imbalance compensation device for a communication receiver, characterized in that: include: A sampling module, used for 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 transmitted 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 transmitted signal includes an I-branch transmitted signal and a Q-branch transmitted signal; A construction module, used 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 the covariance matrix; A derivation module, used for derivation of the logarithmic function of the likelihood function to obtain a group 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 iteration module, used for 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 compensation module is used to compensate the received signal sequence according to the target estimation parameter to obtain a target signal sequence.

10. 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 implement the method according to any one of claims 1 to 8.

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