CN113676432B

CN113676432B - IQ signal calibration method, system and storage medium

Info

Publication number: CN113676432B
Application number: CN202111056599.7A
Authority: CN
Inventors: 颜海龙; 李相宏; 谭红军; 李峰; 肖乾友
Original assignee: Shenzhen MTC Co Ltd
Current assignee: Shenzhen MTC Co Ltd
Priority date: 2021-09-09
Filing date: 2021-09-09
Publication date: 2023-05-16
Anticipated expiration: 2041-09-09
Also published as: CN113676432A

Abstract

The invention discloses an IQ signal calibration method, a system and a storage medium, wherein the method comprises the following steps: step S10, initial IQ signal data is sent to a radio frequency link; step S20, judging whether an I channel is balanced or not according to the initial IQ signal data and a first preset mode; step S30, if the I path is balanced, jumping to step S40, and if the I path is unbalanced, calibrating the I path; step S40, judging whether the Q path is balanced or not in a second preset mode; and S50, if the Q paths are unbalanced, calibrating the Q paths so that the amplitude frequencies of the I paths and the Q paths are symmetrical. Compared with the prior art, the calibration method is simple, not only avoids influencing normal IQ data transmission, but also can achieve the purposes of solving the IQ signal imbalance problem and improving the calibration accuracy.

Description

IQ signal calibration method, system and storage medium

Technical Field

The present invention relates to the field of digital communications technologies, and in particular, to an IQ signal calibration method, system, and storage medium.

Background

In the linearization transmitter product adopting the quadrature modulation technique and the negative feedback technique, there is a problem that the modulated signals I, Q (the same amplitude, 90 degrees phase difference, hereinafter the same) are inconsistent in amplitude, and the signal quality is degraded after the mixing process of the modulator. In order to update and compensate the IQ gain imbalance of the modulator, the IQ two paths of the frequency spectrum are symmetrical, and the process is simply called calibration.

At present, mainly, modulation signal IQ data is sent to a radio frequency circuit, and then gain imbalance parameters of an IQ modulator are updated and compensated by mathematical calculation, so that the purpose of symmetrical two paths of IQ is achieved.

The method for updating the original calibration parameters by adopting the mathematical calculation mode has the problems of complex calculation and low accuracy.

Disclosure of Invention

The main objective of the present invention is to provide an IQ signal calibration method, system and storage medium, which aim to improve the accuracy of IQ signal calibration.

To achieve the above object, the present invention provides an IQ signal calibration method, comprising the steps of:

step S10, initial IQ signal data is sent to a radio frequency link;

step S20, judging whether an I channel is balanced or not according to the initial IQ signal data and a first preset mode;

step S30, if the I path is balanced, jumping to step S40; if the I path is unbalanced, calibrating the I path;

step S40, judging whether the Q path is balanced or not in a second preset mode;

and S50, if the Q paths are unbalanced, calibrating the Q paths so that the amplitude frequencies of the I paths and the Q paths are symmetrical.

The further technical scheme of the present invention is that the step S20 of judging whether the I-channel is balanced according to the initial IQ signal data and the first preset mode includes:

step S201, obtaining a bias voltage value IN of the I path;

step S202, switching circuit link;

step S203, obtaining a bias voltage value IP of the I path;

step S204, calculating a difference delta I between the bias voltage value IN and the bias voltage value IP according to the bias voltage value IN and the bias voltage value IP;

step S205, comparing the difference value delta I with a first preset threshold value;

step S206, if the difference value DeltaI is smaller than or equal to the first preset threshold value, the I path is balanced;

if the difference Δi is greater than the first preset threshold, the I-path is unbalanced.

The further technical scheme of the present invention is that if the I path is balanced, the step S50 of determining whether the Q path is balanced in a second preset manner includes:

step S501, obtaining a bias voltage value QN of the Q path;

step S502, switching circuit link;

step S503, obtaining a bias voltage value QP of the Q path;

step S504, calculating a difference delta Q between the bias voltage value QN and the bias voltage value QP according to the bias voltage value QN and the bias voltage value QP;

step S405, comparing the difference value DeltaQ with a second preset threshold value;

step S406, if the difference Δq is less than or equal to the second preset threshold, balancing the Q path;

in step S407, if the difference Δq is greater than the second preset threshold, the Q path is unbalanced.

The method further comprises the step of calibrating the Q path if the Q path is unbalanced, wherein the step of calibrating the Q path comprises the following steps:

compensating the second step value into the initial signal data of the Q path to obtain a first Q path calibration data value;

transmitting the first Q-path calibration data value and the I-path initial signal data value to the radio frequency circuit;

and repeating the steps S401 to S405 until the difference Δq between the bias voltage value QN and the bias voltage value QP of the Q path is less than or equal to the second preset threshold value.

The further technical scheme of the invention is that if the I path is unbalanced, the step of calibrating the I path comprises the following steps:

compensating the first step value into the initial signal data of the I path to obtain an I path calibration data value;

transmitting the I path calibration data value and the initial signal data value of the Q path to the radio frequency circuit;

and repeating the steps S201 to S205 until the difference delta I between the bias voltage value IN and the bias voltage value IP of the I path is smaller than or equal to the first preset threshold value.

In a further technical scheme of the present invention, if the I path is unbalanced, the step S50 of determining whether the Q path is balanced in a second preset manner includes:

step S4001, transmitting the initial signal data value of the Q path and the I path calibration data value to a radio frequency circuit;

step S4002, obtaining a bias voltage value QN' of the Q path;

step S4003, switching circuit link;

step S4004, obtaining a bias voltage value QP' of the Q path;

step S4005, calculating a difference Δq ' between the bias voltage value QN ' and the bias voltage value QP ' according to the bias voltage value QN ' and the bias voltage value QP ';

step S4006, comparing the difference Δq' with a third preset threshold;

step S4007, if the difference Δq' is less than or equal to the third preset threshold, balancing the Q path;

in step S4008, if the difference Δq' is greater than the third preset threshold, the Q path is unbalanced.

compensating the third stepping value into the initial signal data of the Q path to obtain a second Q path calibration data value;

transmitting the second Q-path calibration data value and the I-path calibration data value to the radio frequency circuit;

and repeating the steps S4002 to S4006 until the difference Δq ' between the bias voltage value QN ' and the bias voltage value QP ' of the Q path is less than or equal to the third preset threshold value.

To achieve the above object, the present invention also proposes an IQ signal calibration system comprising a memory, a processor, and an IQ signal calibration program stored on the processor, which when executed by the processor performs the steps of:

step S10, initial IQ signal data is sent to a radio frequency link;

The further technical scheme of the invention is that the IQ signal calibration program when run by the processor also executes the following steps:

step S201, obtaining a bias voltage value IN of the I path;

step S202, switching circuit link;

step S203, obtaining a bias voltage value IP of the I path;

To achieve the above object, the present invention also proposes a computer readable storage medium having stored thereon an IQ signal calibration program which, when executed by a processor, performs the steps of the method as described above.

The IQ signal calibration method, the IQ signal calibration system and the storage medium have the beneficial effects that: the technical scheme includes that the method comprises the following steps that S10, initial IQ signal data are sent to a radio frequency link; step S20, judging whether an I channel is balanced or not according to the initial IQ signal data and a first preset mode; step S30, if the I path is balanced, jumping to step S40, and if the I path is unbalanced, calibrating the I path; step S40, judging whether the Q path is balanced or not in a second preset mode; and S50, if the Q path is unbalanced, calibrating the Q path so that the amplitude frequencies of the I path and the Q path are symmetrical, and before normal IQ data are sent, firstly sending a group of initial data to judge whether the paths are balanced, and if the paths are unbalanced, starting a calibration flow to obtain a calibration value to compensate the IQ signal, thereby achieving the purpose of solving the imbalance of the IQ signal. The calibration method is simple, and can not only avoid influencing normal IQ data transmission, but also improve accuracy.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of a IQ signal calibration method according to a preferred embodiment of the present invention;

fig. 2 is a schematic diagram of the refinement flow of step S20;

FIG. 3 is a schematic diagram of circuit links;

FIG. 4 is a schematic diagram of a switching circuit;

FIG. 5 is a flow diagram of an adopted calibration scheme for the I-path;

fig. 6 is a flow diagram of an employed calibration scheme for the Q-path.

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the linearization transmitter product adopting the quadrature modulation technology and the negative feedback technology, the problem that the amplitude of the modulation signal I, Q is inconsistent and the signal quality is poor after the frequency mixing treatment of the modulator exists, the invention provides a solution for judging whether the IQ signal is balanced and calibrated.

The technical scheme adopted by the invention is mainly that before normal IQ data is sent, a group of initial data is sent to judge whether the paths are balanced or not, if the paths are unbalanced, a calibration flow is started to obtain calibration values to compensate the IQ signals, and the purpose of solving the imbalance of the IQ signals is achieved. The invention adaptively solves the problem that the method for updating the original calibration parameters by adopting mathematical calculation needs time processing, and the normal IQ data transmission and the calibration accuracy are affected as a result. The calibration method of the scheme is simple, and can not only avoid influencing normal IQ data transmission, but also improve accuracy.

Specifically, the present invention proposes an IQ signal calibration method, as shown in fig. 1, a preferred embodiment of the IQ signal calibration method of the present invention includes the following steps:

step S10, the initial IQ signal data is sent to the radio frequency link.

It should be noted that, in this embodiment, the initial data is sent before normal IQ data is sent, so as to determine whether the I path and the Q path are balanced, and if not, start a calibration procedure to obtain a calibration value to compensate to the IQ signal, so as to achieve the purpose of solving the problem of IQ signal imbalance.

Step S20, judging whether the I channel is balanced according to the initial IQ signal data and a first preset mode.

Step S30, if the I path is balanced, the step S40 is skipped, and if the I path is unbalanced, the I path is calibrated.

Step S40, judging whether the Q path is balanced or not in a second preset mode.

Through the technical scheme, normal IQ data transmission can be prevented from being influenced, and the accuracy of I path and Q path calibration can be improved, so that the I path and the Q path have symmetrical amplitude frequency.

Further, referring to fig. 2, fig. 2 is a schematic diagram of a refinement process of step S20 in fig. 1.

As shown in fig. 2, the step S20 of determining whether the I path is balanced according to the initial IQ signal data and the first preset manner specifically includes:

step S201, obtaining a bias voltage value IN of the I-channel.

In step S202, the switching circuit is linked.

The circuit links are shown in the circuit link schematic diagram in fig. 3, and the circuit when switching the circuit is shown in the circuit switch schematic diagram in fig. 4.

Step S203, acquiring the bias voltage value IP of the I-path.

Step S204, calculating a difference Δi between the bias voltage value IN and the bias voltage value IP according to the bias voltage value IN and the bias voltage value IP.

In step S205, the difference Δi is compared with a first preset threshold value.

The first preset threshold value can be set or adjusted according to actual conditions or experience.

In step S206, if the difference Δi is less than or equal to the first preset threshold, the I-path is balanced.

Further, in this embodiment, if the I path is balanced, the step S40 of determining whether the Q path is balanced in a second predetermined manner includes:

step S401, acquiring a bias voltage value QN of the Q path.

In step S402, the switching circuit is linked.

Step S403, acquiring a bias voltage value QP of the Q path.

Step S404, calculating a difference Δq between the bias voltage value QN and the bias voltage value QP according to the bias voltage value QN and the bias voltage value QP.

Step 405 compares the difference Δq with a second preset threshold value.

The second preset threshold value can be set or adjusted according to actual conditions or experience.

In step S406, if the difference Δq is less than or equal to the second preset threshold, the Q paths are balanced.

Wherein if the Q path is unbalanced, the step of calibrating the Q path includes:

and compensating the second stepping value into the initial signal data of the Q path to obtain a first Q path calibration data value.

Wherein, the second step value can be set or adjusted according to actual conditions or experience.

And transmitting the first Q-path calibration data value and the initial signal data value of the I path to the radio frequency circuit.

In this embodiment, the step of calibrating the I-path if the I-path is unbalanced includes:

and compensating the first stepping value into the initial signal data of the I path to obtain an I path calibration data value.

The first step value may be set or adjusted according to actual conditions or experience.

And transmitting the I path calibration data value and the initial signal data value of the Q path to the radio frequency circuit.

Further, if the I path is unbalanced, the step S40 of determining whether the Q path is balanced in a second preset manner includes:

step S4001, transmitting the initial signal data value of the Q path and the I path calibration data value to a radio frequency circuit.

Step S4002, obtaining a bias voltage value QN' of the Q path.

In step S4003, the switching circuits are linked.

Step S4004 obtains a bias voltage value QP' of the Q path.

Step S4005, calculating a difference Δq ' between the bias voltage value QN ' and the bias voltage value QP ' according to the bias voltage value QN ' and the bias voltage value QP '.

Step S4006, comparing the difference Δq' with a third preset threshold value.

The third preset threshold value can be set or adjusted according to actual conditions or experience.

In step S4007, if the difference Δq' is less than or equal to the third preset threshold, the Q path is balanced.

In this embodiment, the step of calibrating the Q path if the Q path is unbalanced includes:

and compensating the third stepping value into the initial signal data of the Q path to obtain a second Q path calibration data value.

Wherein, the third step value can be set or adjusted according to actual conditions or experience.

And transmitting the second Q-path calibration data value and the I-path calibration data value to the radio frequency circuit.

The IQ signal calibration method according to the present invention is further described in detail below with reference to fig. 5 and 6.

The calibration scheme adopted by the I path in the IQ signal calibration method is similar to the calibration scheme adopted by the Q path, wherein the adopted calibration scheme of the I path is shown in fig. 5, and the adopted calibration scheme of the Q path is shown in fig. 6.

The working principle of the IQ signal calibration method is that the I path and the Q path are calibrated respectively, the digital end sends I, Q data to the radio frequency circuit, and then gain imbalance of the parameter value compensation modulator I, Q is calculated. Specifically, the IQ signal calibration method of the invention comprises the following steps:

1) Calibrating the I, Q paths at the digital end, and taking the I path as an example, firstly setting a threshold value and an IQ data value to be transmitted initially;

2) Transmitting default initial IQ data to a radio frequency link;

3) Reading an I-path bias voltage value IN;

4) The switching circuit is linked;

5) Reading an I-path bias voltage value IP;

6) Calculating the difference between IN and IP;

7) Comparing the difference value with a threshold value, and if the difference value is smaller than or equal to the threshold value, recognizing that the I path is balanced in comparison, and ending the detection and calibration process; if the current value is larger than the current value, the I path is considered to be unbalanced, and the detection and calibration flow needs to be continued;

8) The difference value is larger than the threshold value, and data with unchanged I change (initial value+step value) Q is sent;

9) Repeating the steps 3), 4), 5), 6), 7) and 8) until the difference value is within the threshold value range, wherein the I path unbalance calibration is considered to be completed, the obtained I path change value is compensated into I path signal data, and the problem of I path signal unbalance is solved; similarly, the Q paths are similar in operation steps:

10 Transmitting I (previously calibrated value) Q data to the radio frequency link;

11 Reading a Q path bias voltage value QN;

12 A switching circuit link;

13 Reading a Q-path bias voltage value QP;

14 Calculating the difference between QN and QP;

15 Comparing the difference value with a threshold value, and if the difference value is smaller than or equal to the threshold value, recognizing that the Q paths are balanced in comparison, and ending the detection and calibration process; if the number is greater than the threshold value, the Q path is considered to be unbalanced, and the detection and calibration flow needs to be continued;

16 And (3) transmitting data with unchanged Q change (initial value+step value) I, wherein the difference value is larger than the threshold value.

17 Repeating 11), 12), 13), 14), 15), 16) until the difference value is within the threshold value range, and recognizing that the Q-channel unbalance calibration is finished, compensating the obtained Q-channel variation value into the Q-channel signal data, thereby solving the Q-channel signal unbalance problem.

It should be noted that in actual debugging, the threshold value and the step value may be adjusted to achieve the effect of higher accuracy.

The IQ signal calibration method has the beneficial effects that: the technical scheme includes that the method comprises the following steps that S10, initial IQ signal data are sent to a radio frequency link; step S20, judging whether an I channel is balanced or not according to the initial IQ signal data and a first preset mode; step S30, if the I path is balanced, jumping to step S40, and if the I path is unbalanced, calibrating the I path; step S40, judging whether the Q path is balanced or not in a second preset mode; and S50, if the Q path is unbalanced, calibrating the Q path so that the amplitude frequencies of the I path and the Q path are symmetrical, and before normal IQ data are sent, firstly sending a group of initial data to judge whether the paths are balanced, and if the paths are unbalanced, starting a calibration flow to obtain a calibration value to compensate the IQ signal, thereby achieving the purpose of solving the imbalance of the IQ signal. The calibration method is simple, and can not only avoid influencing normal IQ data transmission, but also improve accuracy.

step S10, the initial IQ signal data is sent to the radio frequency link.

Further, the IQ signal calibration procedure, when executed by the processor, performs the following steps:

step S201, obtaining a bias voltage value IN of the I-channel.

In step S202, the switching circuit is linked.

Step S203, acquiring the bias voltage value IP of the I-path.

The IQ signal calibration system has the beneficial effects that: the technical scheme includes that the method comprises the following steps that S10, initial IQ signal data are sent to a radio frequency link; step S20, judging whether an I channel is balanced or not according to the initial IQ signal data and a first preset mode; step S30, if the I path is balanced, jumping to step S40, and if the I path is unbalanced, calibrating the I path; step S40, judging whether the Q path is balanced or not in a second preset mode; and S50, if the Q path is unbalanced, calibrating the Q path so that the amplitude frequencies of the I path and the Q path are symmetrical, and before normal IQ data are sent, firstly sending a group of initial data to judge whether the paths are balanced, and if the paths are unbalanced, starting a calibration flow to obtain a calibration value to compensate the IQ signal, thereby achieving the purpose of solving the imbalance of the IQ signal. The calibration method is simple, and can not only avoid influencing normal IQ data transmission, but also improve accuracy.

To achieve the above objective, the present invention also provides a computer readable storage medium, on which an IQ signal calibration program is stored, which when executed by a processor performs the steps of the method described in the above embodiments, and will not be described in detail herein.

The foregoing description is only of the preferred embodiments of the present invention and is not intended to limit the scope of the invention, and all equivalent structural changes made by the specification and drawings of the present invention or direct/indirect application in other related technical fields are included in the scope of the present invention.

Claims

1. An IQ signal calibration method, comprising the steps of:

step S10, initial IQ signal data is sent to a radio frequency circuit;

step S30, if the I path is balanced, jumping to step S40, and if the I path is unbalanced, calibrating the I path;

step S50, if the Q path is unbalanced, calibrating the Q path so that the amplitude frequencies of the I path and the Q path are symmetrical;

the step S20 of determining whether the I-channel is balanced according to the initial IQ signal data and the first preset manner includes:

step S201, obtaining a bias voltage value IN of the I path;

step S202, switching circuit link;

step S203, obtaining a bias voltage value IP of the I path;

step S207, if the difference value DeltaI is larger than the first preset threshold value, the I path is unbalanced;

if the I paths are balanced, the step S40 of determining whether the Q paths are balanced in a second preset manner includes:

step S401, obtaining a bias voltage value QN of the Q path;

step S402, switching circuit link;

step S403, obtaining a bias voltage value QP of the Q path;

step S404, calculating a difference Δq between the bias voltage value QN and the bias voltage value QP according to the bias voltage value QN and the bias voltage value QP;

step S407, if the difference Δq is greater than the second preset threshold, the Q path is unbalanced;

the step of calibrating the Q path if the Q path is unbalanced includes:

repeatedly executing the steps S401 to S405 until the difference Δq between the bias voltage value QN and the bias voltage value QP of the Q path is less than or equal to the second preset threshold value;

the step of calibrating the I-path if the I-path is unbalanced includes:

2. The IQ signal calibration method according to claim 1 wherein if the I-path is unbalanced, step S40 of determining whether the Q-path is balanced in a second predetermined manner comprises:

step S4002, obtaining a bias voltage value QN' of the Q path;

step S4003, switching circuit link;

step S4004, obtaining a bias voltage value QP' of the Q path;

step S4006, comparing the difference Δq' with a third preset threshold;

3. The IQ signal calibration method according to claim 2 wherein the step of calibrating the Q path if the Q path is unbalanced comprises:

4. An IQ signal calibration system comprising a memory, a processor, and an IQ signal calibration program stored on the processor, which when executed by the processor performs the steps of:

step S10, initial IQ signal data is sent to a radio frequency circuit;

step S201, obtaining a bias voltage value IN of the I path;

step S202, switching circuit link;

step S203, obtaining a bias voltage value IP of the I path;

step S401, obtaining a bias voltage value QN of the Q path;

step S402, switching circuit link;

step S403, obtaining a bias voltage value QP of the Q path;

the step of calibrating the Q path if the Q path is unbalanced includes:

the step of calibrating the I-path if the I-path is unbalanced includes:

5. The IQ signal calibration system according to claim 4 wherein the IQ signal calibration program when executed by the processor further performs the steps of:

6. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon an IQ signal calibration program which, when run by a processor, performs the steps of the method according to any of claims 1 to 3.