CN107800656B - Method and equipment for compensating IQ imbalance - Google Patents
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Abstract
The invention discloses a method and equipment for compensating IQ imbalance, which are used for directly carrying out IQ compensation on a signal in a time domain. The methodThe method comprises the following steps: obtaining the mean value of the conjugate of the data of the nth sampling point and the data of the (n + m) th sampling point in the L sampling points included in the digital signal x (n) for carrying out the autocorrelation operation to obtain the conjugate autocorrelation mean value Rxx(n; m); wherein m is more than or equal to 1 and less than or equal to L, and n is more than or equal to 1 and less than or equal to L-m; obtaining the average value of the data of the nth sampling point and the data of the (n + m) th sampling point in the L sampling points for the autocorrelation operation to obtain an autocorrelation average value Cxx(n; m); according to the mean value R of the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation coefficient w, which is a coefficient related to an IQ imbalance value of the digital signal x (n); compensating the IQ imbalance value of the digital signal x (n) according to the compensation coefficient w to obtain a compensated signal
Description
Technical Field
The present invention relates to the field of communications technologies, and in particular, to a method and an apparatus for compensating for IQ imbalance.
Background
Currently, the receiver mainly includes a zero intermediate frequency receiver and a superheterodyne receiver. Wherein, zero intermediate frequency receiver can be after receiving radio frequency signal with the direct down conversion of radio frequency signal to baseband signal, and at this in-process, does not need processing parts such as image rejection filter and intermediate frequency filter, therefore zero intermediate frequency receiver is than super heterodyne receiver, and the structure is simpler, changes in the integration, and is more extensive in current communication system's application.
In a zero-if receiver, when down-converting a radio frequency or intermediate frequency signal into a baseband signal, the baseband signal is separated into an In-phase (In-phase) vector and a Quadrature (Quadrature) vector, and the down-conversion process can be implemented by two sine waves with the same amplitude and 90 degrees phase difference. Since the conversion process is performed in the analog operation domain, i.e., the received analog signal is processed, a certain error is introduced. Furthermore, the two sine waves with the same amplitude and the phase difference of 90 degrees have gain and phase errors, and the influence of the errors on the performance of the receiver is called IQ imbalance. Generally, the gain error is in the range of 1 to 5%, and the phase error is in the range of about 1 to 5 degrees. IQ imbalance causes the gain and phase of the signals of the two IQ paths to be unbalanced relative to each other, which can cause significant degradation in receiver performance when the imbalance exceeds a certain threshold.
The following 3 methods are mainly used to compensate for IQ imbalance.
First, the analog signal at the analog end is compensated by adding a compensation circuit at the analog end. However, this method requires an additional circuit at the analog end, which not only increases the cost, but also cannot ensure the compensation accuracy because the analog signal is directly compensated.
Second, the IQ imbalance is estimated by using a known signal structure, and then the next signal is compensated. However, this method can only estimate IQ imbalance for a specific signal, for example, for a preamble structure in a signal of a WIreless Fidelity (WIFI) network, and then compensate for the IQ imbalance, so that it can only be effective for a signal including a known structure, and the requirement of this method for delay is high.
Thirdly, by using a data-aided off-line estimation method, in which a known signal such as a sine wave is input into a receiver, and the signal processed by the receiver is compared with the original signal to estimate the IQ imbalance of the receiver, but the IQ imbalance estimated by this method is a fixed value, that is, the IQ imbalance compensated for the subsequently received signal is a fixed value, and obviously, the result of such compensation can only be roughly compensated for the signal, that is, the compensation precision is not high.
Disclosure of Invention
The embodiment of the invention provides a method and equipment for compensating IQ imbalance, which are used for directly carrying out IQ compensation on a signal in a time domain.
In a first aspect, a method for compensating for IQ imbalance is provided, the method comprising:
obtaining the mean value of the conjugate of the data of the nth sampling point and the data of the (n + m) th sampling point in the L sampling points included in the digital signal x (n) for carrying out the autocorrelation operation to obtain the conjugate autocorrelation mean value Rxx(n; m); wherein m is more than or equal to 1 and less than or equal to L, and n is more than or equal to 1 and less than or equal to L-m;
obtaining the nth sampling point in the L sampling pointsCarrying out the mean value of the autocorrelation operation on the data of the sampling points and the data of the n + m sampling points to obtain an autocorrelation mean value Cxx(n；m)；
According to the mean value R of the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation coefficient w, which is a coefficient related to an IQ imbalance value of the digital signal x (n);
compensating the IQ imbalance value of the digital signal x (n) according to the compensation coefficient w to obtain a compensated signal
In a possible implementation, the mean value R is calculated from the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation factor w, comprising:
according to the mean value R of the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n, m), calculating by using a compensation coefficient calculation formula to obtain the compensation coefficient w, wherein the compensation coefficient calculation formula is as follows:
in a possible embodiment, the IQ imbalance of the digital signal x (n) is compensated according to the compensation coefficient w to obtain a compensated signal
The method comprises the following steps:
calculating by using an IQ compensation formula according to the compensation coefficient w to obtain a compensated signal
The IQ compensation formula is as follows:
wherein x is*(n) is the conjugate of the digital signal x (n).
In a possible embodiment, the number L of sampling points of the digital signal x (n) is set according to a delay requirement and/or a computational complexity requirement for compensating the IQ imbalance value of the digital signal x (n).
In a second aspect, an apparatus for compensating for IQ imbalance is provided, the apparatus comprising:
a calculating unit, configured to obtain an average value of the conjugate of the data of the nth sampling point and the data of the (n + m) th sampling point in the L sampling points included in the digital signal x (n) and perform autocorrelation operation to obtain a conjugate autocorrelation average value Rxx(n; m); wherein m is more than or equal to 1 and less than or equal to L, and n is more than or equal to 1 and less than or equal to L-m; and acquiring the mean value of the data of the nth sampling point and the data of the (n + m) th sampling point in the L sampling points for carrying out autocorrelation operation to obtain an autocorrelation mean value Cxx(n；m)；
A determining unit for determining the mean value R according to the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation coefficient w, which is a coefficient related to an IQ imbalance value of the digital signal x (n);
a compensation unit, configured to compensate the IQ imbalance of the digital signal x (n) according to the compensation coefficient w to obtain a compensated signal
In a possible implementation, the determining unit is configured to determine the mean value R based on the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation factor w, comprising:
the determining unit is used for determining the mean value R according to the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n, m), calculating by using a compensation coefficient calculation formula to obtain the compensation coefficient w, wherein the compensation coefficient calculation formula is as follows:
in a possible embodiment, the compensation unit compensates the IQ imbalance of the digital signal x (n) according to the compensation coefficient w to obtain a compensated signal
The method comprises the following steps:
the compensation unit calculates by using IQ compensation formula according to the compensation coefficient w to obtain the compensated signal
The IQ compensation formula is as follows:
wherein x is*(n) is the conjugate of the digital signal x (n).
In a possible embodiment, the number L of sampling points of the digital signal x (n) is set according to a delay requirement and/or a computational complexity requirement for compensating the IQ imbalance value of the digital signal x (n).
In a third aspect, a computer arrangement is provided, characterized in that the arrangement comprises a processor for implementing the steps of the method for compensating for IQ-imbalance as provided in the first aspect when executing a computer program stored in a memory.
In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored, which computer program, when being executed by a processor, realizes the steps of the method for compensating for IQ-imbalance as provided in the first aspect.
In the embodiment of the present invention, in the method, after the digital signal x (n) is collected, the mean value R of the conjugate autocorrelation of L sampling points in the signal is calculatedxx(n; m), and the autocorrelation mean Cxx(n; m) and further based on the conjugate autocorrelation meanRxx(n; m), and the autocorrelation mean Cxx(n; m) determining a compensation coefficient w to perform IQ compensation on the current L sampling points. The method provided by the embodiment of the invention can compensate the currently acquired signal in real time in the time domain, and a feedback module is not required to be added, so that the time delay is shorter.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a flowchart illustrating a method for compensating IQ imbalance according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of an apparatus for compensating for IQ mismatch according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a computer device according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.
The technical background of the embodiments of the present invention is described below.
Currently, in a zero-if receiver, a down-conversion process is performed in an analog operation domain, that is, a received analog signal is processed, so that a certain error is caused. Furthermore, the two sine waves with the same amplitude and the phase difference of 90 degrees have amplitude and phase errors, and the influence of the errors on the performance of the receiver is called IQ imbalance. IQ imbalance causes the gain and phase of the signals of the two IQ paths to be unbalanced relative to each other, which can cause significant degradation in receiver performance when the imbalance exceeds a certain threshold.
In view of this, the present invention provides a method for compensating IQ imbalance, in which a digital signal x (n) is collected and then a conjugate autocorrelation mean R of L samples in the signal is calculatedxx(n; m), and the autocorrelation mean Cxx(n; m) and further based on the conjugate autocorrelation mean Rxx(n; m), and the autocorrelation mean Cxx(n; m) determining a compensation coefficient w to perform IQ compensation on the current L sampling points. The method provided by the embodiment of the invention can compensate the currently acquired signal in real time in the time domain, and a feedback module is not required to be added, so that the time delay is shorter.
The technical scheme provided by the embodiment of the invention is described below by combining the accompanying drawings.
Referring to fig. 1, an embodiment of the present invention provides a method for compensating IQ imbalance, which can be implemented by providing an apparatus for compensating IQ imbalance according to an embodiment of the present invention, which can be implemented by a zero intermediate frequency receiver, for example. The method comprises the following steps:
step 101: obtaining the mean value of the conjugate of the data of the nth sampling point and the data of the (n + m) th sampling point in the L sampling points included in the digital signal x (n) for carrying out the autocorrelation operation to obtain the conjugate autocorrelation mean value Rxx(n; m); wherein m is more than or equal to 1 and less than or equal to L, and n is more than or equal to 1 and less than or equal to L-m;
step 102: obtaining the average value of the data of the nth sampling point and the data of the (n + m) th sampling point in the L sampling points for the autocorrelation operation to obtain the autocorrelation average value Cxx(n；m)；
Step 103: from the mean value of the conjugate autocorrelation Rxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation coefficient w, which is a coefficient related to the IQ imbalance value of the digital signal x (n);
step 104: compensating IQ imbalance of the digital signal x (n) according to the compensation coefficient w to obtainTo the compensated signal
First, a compensation principle for implementing the method according to the embodiment of the present invention is described below, which may specifically be:
in a zero-if receiver, the final result of IQ imbalance consists mainly of gain and phase distortion. Assuming that the signal received by the receiver is x (n), the baseband signal of the signal is z (n), where the signals x (n) and z (n) are both digital signals, i.e. time domain expressions of the signals, the signal x (n) received by the receiver can be represented as:
x(n)＝K1(Θ)z(n)+K2(Θ)z*(n) formula (1)
Wherein, K1(theta) and K2(Θ) is used to characterize the coefficients, z, related to gain and phase errors in IQ imbalance*(n) is the conjugate of the baseband signal z (n). Specifically, K1(theta) and K2(Θ) can be expressed as:
wherein,
g represents the distortion of the gain and the gain,
indicating phase distortion.
In the examples of the present invention, it can be seen from formula (1) that if K is2If (Θ) is 0, the finally obtained signal has only a simple multiplicative relationship with the baseband signal, that is, the finally obtained signal also has only a multiplicative relationship with the sum of I and Q, that is, the finally obtained signal is only K of the baseband signal1(Θ) times, and the relationship between I and QAnd also keeps consistent with the baseband signal, the IQ imbalance problem does not exist, so that the IQ imbalance problem can be solved by only eliminating the conjugate signal in the formula (1). Wherein, since the range of IQ imbalance is usually small, the coefficient K causing IQ imbalance2(Θ) will also be generally small, that is, K can be considered to be2The value of (Θ) is much less than K1(Θ). Therefore, in the embodiment of the present invention, a compensation coefficient w for eliminating the conjugate signal is introduced, and the value of w is:
in the embodiment of the invention, the compensated signal is assumed to be
Then it is possible to obtain:
wherein, according to the value of w in the formula (2), the following can be obtained:
wherein, the formula (4) is substituted into the formula (3) to obtain:
in the embodiment of the present invention, it can be seen from the above process that, as long as the compensation coefficient w is calculated, the conjugate signal can be eliminated, and a signal obtained by compensating for IQ imbalance can be obtained. In order to calculate the compensation coefficient w, a conjugate autocorrelation mean estimation and an autocorrelation mean estimation may be performed on the received signal x (n). Wherein, the received signal x (n) is a digital signal, i.e. an Analog-to-digital converter (Analog-to-digital-Dig)ital Converter, ADC) samples an analog signal to obtain a digital signal. The conjugate autocorrelation mean value estimation refers to performing autocorrelation operation on the data of the nth sampling point and the data of the (n + m) th sampling point in the received signal x (n), and then calculating the mean value of the values obtained by the conjugate autocorrelation operation, so as to obtain a conjugate autocorrelation mean value Rxx(n; m); the autocorrelation mean value estimation refers to performing autocorrelation operation on the data of the nth sampling point and the data of the (n + m) th sampling point in the received signal x (n), and then calculating the mean value of the values obtained by the autocorrelation operation, so as to obtain the autocorrelation mean value Cxx(n; m). In particular, Rxx(n; m) and CxxThe calculation formula of (n; m) is:
wherein E { x (n) x*The (n + m) operation means that after the self-correlation operation is performed on the conjugate of the data of the nth sampling point and the data of the n + m sampling points, the mean value of the values obtained by the conjugate self-correlation operation is obtained;
e { x (n) x (n + m) } operation means that after the autocorrelation operation is performed on the data of the nth sampling point and the data of the n + m sampling points, the average value of the values obtained by the autocorrelation operation is obtained;
Rzz(n; m) and R* zz(n; m) respectively represent the mean value of the conjugate autocorrelation operation and the conjugate of the mean value of the conjugate autocorrelation operation of the baseband signal z (n);
K1and K2Are each independently of K1(theta) and K2(Θ) corresponds to the formula (6) and (7), and therefore, K is the same as K1(theta) and K2(Θ) is simplified, but the meaning expressed is the same.
In order to simplify the calculation process, in the embodiment of the invention, R under special conditionsxx(n(ii) a m) and Cxx(n; m) is calculated, for example, when m is 0. The following description will be given by taking m as 0:
when m is 0, then
Rzz(n；0)＝E{z(n)z*(n)}＝R* zz(n; 0) formula (8)
Then equation (6) can be expressed as:
Rxx(n；0)＝(|K1|2+|K2|2)Rzz(n; 0) formula (9)
Accordingly, equation (7) can be expressed as:
Cxx(n；0)＝2K1K2Rzz(n; 0) formula (10)
In the embodiment of the present invention, the period of the baseband signal z (n) may be P, then Rzz(n；0)、Rxx(n; 0) and CxxThe periods of (n; 0) are also both P, and after Fourier transformation of equations (9) and (10), we can obtain:
wherein, FRxx(k; 0) and FCxx(k; 0) are Fourier transformed expressions of Rxx (n; 0) and Cxx (n; 0), respectively.
In the embodiment of the invention, K is2Is much less than K1And thus can be represented by | K1|2＞＞|K2|2I.e. | K1|2Far greater than | K2|2Then | K can be obtained1|2Can be approximately equal to | K1|2+|K2|2Then further, then:
in order to make the following derivation process more concise, FC may be madexx(k；0)＝cx，FRxx(k；0)＝rxTherefore, equation (13) can be simplified as:
rx＝(|K1|2+|K2|2) Formula (14)
cx＝2K1K2Formula (15)
By the formula (15), can be obtained
This result is substituted into equation (14) to obtain:
will | K1|2As a variable, r isxAnd cxWhen considered as a constant, a one-dimensional quadratic equation can be obtained by equation (16):
solving the equation of equation (17) yields:
further, by substituting the result obtained by the above solution into equation (13), it is possible to obtain:
that is, it is possible to finally obtain:
since the signal is converted from the time domain to the frequency domain by fourier transform and analyzed, in order to directly compensate the signal in the time domain, equation (20) may be subjected to inverse fourier transform and further converted to the time domain and analyzed, and thus:
since the above process is analyzed in the special case where m is 0, but the formula (21) can be easily extended to other cases, and it is possible to obtain:
in the embodiment of the present invention, as can be seen from equation (22), the compensation coefficient w for IQ imbalance is ultimately only related to the conjugate autocorrelation mean and the autocorrelation mean of the signal, and it is not necessary to estimate the gain and phase errors of IQ imbalance, thereby greatly simplifying the calculation process.
Therefore, in the embodiment of the present invention, after the receiver receives the signal x (n), an average value of the conjugate of the data of the nth sampling point and the data of the n + m sampling points in the L sampling points included in the signal x (n) may be calculated to obtain the conjugate autocorrelation average value Rxx(n; m); wherein m is more than or equal to 1 and less than or equal to L, n is more than or equal to 1 and less than or equal to L-m, and calculating the average value of the autocorrelation operation of the data of the nth sampling point and the data of the n + m sampling points in the L sampling points to obtain the autocorrelation average value Cxx(n; m). Here, the digital signal x (n) includes L samples that may be a part of a complete signal, that is, when calculating the conjugate autocorrelation mean and the autocorrelation mean, the conjugate autocorrelation mean and the autocorrelation mean of the L samples may be calculated once when the AD converter samples a part of the complete signal, for example, L samples, that is, calculated once every L samples, so as to reduce the complexity of each calculation and ensure the delay requirement of compensation. Specifically, the value of L can be calculated according to the actual time delay requirementThe computational complexity requirement is set, for example, L may be set to 16. Of course, the embodiment of the present invention may also perform calculation on data of all sampling points included in a complete signal. In addition, in order to ensure that all the data in the data of the L sampling points can be subjected to autocorrelation operation or conjugate autocorrelation operation, a subsequent compensation coefficient can be determined according to the data of the L sampling points to more accurately compensate the IQ imbalance value of the signal, and m can be set to a value not less than L/2.
Step 101 and step 102 do not have a substantial sequence in the actual application process, that is, the processes of step 101 and step 102 may be performed simultaneously or sequentially, for example, the process of step 101 is performed first, and then the process of step 102 is performed continuously; or the process of step 102 is executed first, and then the process of step 101 is executed continuously, which is not limited in this embodiment of the present invention.
In the embodiment of the invention, the conjugate autocorrelation mean value R is obtainedxx(n; m) and the autocorrelation mean CxxAfter (n; m), it is then possible to follow the mean value of the conjugate autocorrelation Rxx(n; m) and the autocorrelation mean Cxx(n; m) determining the compensation factor w. Specifically, the mean value R of the conjugate autocorrelation obtained by calculation is calculatedxx(n; m) and the autocorrelation mean Cxx(n; m) is substituted into a compensation coefficient calculation formula, i.e., formula (22), to calculate the compensation coefficient w, i.e., the compensation coefficient is calculated by:
in practical applications, m may be set to 0 in order to achieve higher accuracy of the calculation result, i.e. the calculation is performed according to the following formula:
it can be seen that when m is 0, then the conjugate autocorrelation mean Rxx(n; m) is carried out for each sample point data and the sample point data conjugateThe mean after autocorrelation and the autocorrelation mean CxxAnd (n; m) is the average value of each sampling point data and the sampling point data after the autocorrelation operation, so that the autocorrelation operation times are more when the autocorrelation operation is performed once every L sampling points, and the finally obtained compensation result is more accurate.
In the embodiment of the present invention, after obtaining the compensation coefficient w, the IQ imbalance of the digital signal x (n) may be compensated according to the compensation coefficient w to obtain a compensated signal
Specifically, the compensation coefficient w is substituted into the IQ compensation formula for calculation to obtain the compensated signal
The IQ compensation formula is also equation (3), i.e.:
in summary, in the embodiment of the present invention, the compensation coefficient w is obtained by calculating according to the data of the L sampling points, and during compensation, the data of the L sampling points may also be compensated according to the compensation coefficient w, that is, a feedback module does not need to be added, so that the time delay can be ensured to be lower. Meanwhile, from another aspect, in the method in the embodiment of the present invention, not only is there no need to add any hardware module, but also the compensated signal does not need to include a known data structure, and the compensation estimation can be performed for all signal structures, which is simple and effective, and has a wider application range.
The following describes the apparatus provided by the embodiment of the present invention with reference to the drawings.
Referring to fig. 2, an embodiment of the present invention provides an apparatus 20 for compensating IQ imbalance based on the same inventive concept, the apparatus comprising:
a calculating unit 201 for obtaining the nth sample point of the L sample points included in the digital signal x (n)The mean value of the self-correlation operation of the conjugation of the data and the data of the (n + m) th sampling point is obtained to obtain a conjugate self-correlation mean value Rxx(n; m); wherein m is more than or equal to 1 and less than or equal to L, and n is more than or equal to 1 and less than or equal to L-m; and acquiring the mean value of the data of the nth sampling point and the data of the (n + m) th sampling point in the L sampling points for carrying out autocorrelation operation to obtain an autocorrelation mean value Cxx(n；m)；
A determining unit 202 for determining a mean value R from the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation coefficient w, which is a coefficient related to the IQ imbalance value of the digital signal x (n);
a compensation unit 203 for compensating the IQ imbalance of the digital signal x (n) according to a compensation coefficient w to obtain a compensated signal
In a possible implementation, the determining unit 202 is configured to determine the mean value R based on the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation factor w, comprising:
the determining unit 202 determines the mean value R according to the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n; m), calculating by using a compensation coefficient calculation formula to obtain a compensation coefficient w, wherein the compensation coefficient calculation formula is as follows:
in a possible embodiment, the compensation unit 203 compensates the IQ imbalance of the digital signal x (n) according to the compensation coefficient w to obtain a compensated signal
The method comprises the following steps:
the compensation unit 203 calculates according to the compensation coefficient w by using an IQ compensation formula to obtain a compensated signal
The IQ compensation formula is:
wherein x is*(n) is the conjugate of the digital signal x (n).
In one possible embodiment, the number L of sampling points of the digital signal x (n) is set according to the delay requirement and/or the computational complexity requirement for compensating the IQ imbalance value of the digital signal x (n).
The apparatus may be used to perform the method provided by the embodiment shown in fig. 1, for example the apparatus is a zero intermediate frequency receiver as described above. Therefore, for functions and the like that can be realized by each functional module of the device, reference may be made to the description of the embodiment shown in fig. 1, which is not repeated.
Referring to fig. 3, an embodiment of the present invention further provides a computer apparatus, which includes a processor 301, and the processor 301 is configured to implement the steps of the method for compensating for IQ imbalance according to the embodiment of the present invention when executing the computer program stored in the memory.
Optionally, at least one processor 301 may specifically include a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), one or more integrated circuits for controlling program execution, a hardware circuit developed by using a Field Programmable Gate Array (FPGA), and a baseband processor.
Optionally, the at least one processor 301 may include at least one processing core.
Optionally, the computer apparatus further comprises a memory 302, and the memory 302 may include a Read Only Memory (ROM), a Random Access Memory (RAM), and a disk memory. The memory 302 is used for storing data required by the at least one processor 301 during operation. The number of the memories 302 is one or more. The memory 302 is also shown in fig. 3, but it should be understood that the memory 302 is not an optional functional module, and is therefore shown in fig. 3 by a dotted line.
In the embodiments of the present invention, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described embodiments of the apparatus are merely illustrative, and for example, the described unit or division of units is only one division of logical functions, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical or other form.
The functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be an independent physical module.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, all or part of the technical solutions of the embodiments of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device, such as a personal computer, a server, or a network device, or a processor (processor) to execute all or part of the steps of the methods according to the embodiments of the present invention. And the aforementioned storage medium includes: various media that can store program codes, such as a universal serial bus flash drive (usb flash drive), a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.
The above embodiments are only used to describe the technical solutions of the present application in detail, but the above embodiments are only used to help understanding the method of the embodiments of the present invention, and should not be construed as limiting the embodiments of the present invention. Variations or substitutions that may be readily apparent to one skilled in the art are intended to be included within the scope of the embodiments of the present invention.
Claims (10)
1. A method of compensating for IQ imbalance, comprising:
obtaining the mean value of the conjugate of the data x (n) of the nth sampling point and the data x (n + m) of the (n + m) th sampling point in the L sampling points included in the digital signal x for the autocorrelation operation to obtain the conjugate autocorrelation mean value Rxx(n; m); wherein m is more than or equal to 1 and less than L, and n is more than or equal to 1 and less than or equal to L-m;
obtaining the average value of the autocorrelation calculation of the data x (n) of the nth sampling point and the data x (n + m) of the (n + m) th sampling point in the L sampling points to obtain the autocorrelation average value Cxx(n；m)；
According to the mean value R of the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation coefficient w, which is a coefficient related to an IQ imbalance value of the digital signal x;
compensating the IQ imbalance value of the digital signal x according to the compensation coefficient w to obtain a compensated signal
2. The method of claim 1, wherein said deriving is based on said conjugate autocorrelation mean Rxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation factor w, comprising:
according to the mean value R of the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n, m), calculating by using a compensation coefficient calculation formula to obtain the compensation coefficient w, wherein the compensation coefficient calculation formula is as follows:
3. the method of claim 1, wherein the pairing of the numbers according to the compensation factor wCompensating IQ imbalance value of signal x to obtain compensated signal
The method comprises the following steps:
calculating by using an IQ compensation formula according to the compensation coefficient w to obtain a compensated signal
The IQ compensation formula is as follows:
wherein x is*(n) is the conjugate of said x (n).
4. A method according to any one of claims 1 to 3, wherein the number L of sampling points of the digital signal x is set according to a delay requirement and/or a computational complexity requirement for compensating the IQ imbalance value of the digital signal x.
5. An apparatus for compensating for IQ imbalance, comprising:
a calculating unit, configured to obtain an average value of a conjugate autocorrelation operation performed between data x (n) of an nth sampling point and data x (n + m) of an n + m sampling point in L sampling points included in the digital signal x, and obtain a conjugate autocorrelation average value Rxx(n; m); wherein m is more than or equal to 1 and less than L, and n is more than or equal to 1 and less than or equal to L-m; and acquiring the average value of the autocorrelation operation of the data x (n) of the nth sampling point and the data x (n + m) of the (n + m) th sampling point in the L sampling points to obtain an autocorrelation average value Cxx(n；m)；
A determining unit for determining the mean value R according to the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation coefficient w, which is a coefficient related to an IQ imbalance value of the digital signal x;
a compensation unit for compensating according to the compensationCompensating IQ imbalance value of the digital signal x by compensation coefficient w to obtain compensated signal
6. The apparatus of claim 5, wherein the determination unit is based on the conjugate autocorrelation mean Rxx(n; m) and the autocorrelation mean Cxx(n; m) determining a compensation factor w, comprising:
the determining unit is used for determining the mean value R according to the conjugate autocorrelationxx(n; m) and the autocorrelation mean Cxx(n, m), calculating by using a compensation coefficient calculation formula to obtain the compensation coefficient w, wherein the compensation coefficient calculation formula is as follows:
7. the apparatus according to claim 5, wherein the compensation unit compensates the IQ imbalance value of the digital signal x according to the compensation coefficient w to obtain a compensated signal
The method comprises the following steps:
the compensation unit calculates by using IQ compensation formula according to the compensation coefficient w to obtain the compensated signal
The IQ compensation formula is as follows:
wherein x is*(n) is the conjugate of said x (n).
8. The apparatus according to any of claims 5 to 7, wherein the number L of sampling points of the digital signal x is set according to a delay requirement and/or a computational complexity requirement for compensating IQ imbalance values of the digital signal x.
9. A computer arrangement, characterized in that the arrangement comprises a processor for implementing the steps of the method according to any of claims 1-4 when executing a computer program stored in a memory.
10. A computer-readable storage medium having stored thereon a computer program, characterized in that: the computer program realizing the steps of the method according to any one of claims 1-4 when executed by a processor.
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| CN101815056A (en) * | 2010-03-05 | 2010-08-25 | 华为技术有限公司 | IQ unbalanced calibration method and equipment of baseband signals in wireless communication receiving machine |
| CN102594381A (en) * | 2012-02-03 | 2012-07-18 | 京信通信系统（中国）有限公司 | Receiver and image suppression method thereof |
| CN103581078A (en) * | 2013-07-12 | 2014-02-12 | 电子科技大学 | IQ imbalance compensation method based on Golay complementary sequences |
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| CN101815056A (en) * | 2010-03-05 | 2010-08-25 | 华为技术有限公司 | IQ unbalanced calibration method and equipment of baseband signals in wireless communication receiving machine |
| CN102594381A (en) * | 2012-02-03 | 2012-07-18 | 京信通信系统（中国）有限公司 | Receiver and image suppression method thereof |
| CN103581078A (en) * | 2013-07-12 | 2014-02-12 | 电子科技大学 | IQ imbalance compensation method based on Golay complementary sequences |
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