Transmitter local oscillator leakage calibration method and device
By acquiring DC vector values and calculating DC variable values in different gain modes, the additional local oscillator leakage signal is adjusted to offset the initial local oscillator leakage signal, thus solving the calibration error problem caused by transmitter local oscillator leakage signal and improving calibration accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-07
- Publication Date
- 2026-03-13
AI Technical Summary
In the prior art, the local oscillator leakage signal of the transmitter causes calibration calculation errors through the calibration path, affecting the calibration accuracy.
By acquiring DC vector values in different gain modes, calculating DC variable values, and adjusting the additional local oscillator leakage signal to offset the initial local oscillator leakage signal based on the ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal, calibration compensation is achieved.
It improves the accuracy of transmitter local oscillator leakage calibration and avoids the impact of interference paths on calibration.
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Figure CN121664324A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of wireless communication technology, and in particular to a transmitter local oscillator leakage calibration method and apparatus. Background Technology
[0002] In wireless communication, the transmitter is generally composed of a baseband amplifier, a mixer, and a radio frequency amplifier. Offset of the baseband amplifier, mismatch of the mixer, coupling of the local oscillator signal, etc., can all cause unwanted local oscillator signals to leak out from the transmitter, thereby interfering with demodulation and spectrum sensing on the receiving side.
[0003] Currently, the attenuated transmitted signal is typically received through a calibration path, and then down-converted to the receiving baseband using a mixer. Since the local oscillator frequencies for both transmission and reception are the same, the local oscillator leakage signal after down-conversion will be reflected in the DC of the receiving baseband. Calibration is completed by adjusting the DC offset in the transmitter baseband, observing the changes in DC in the calibration path, and then using algorithms such as vector calculation, traversal scanning, or successive approximation to compensate for the transmitted local oscillator leakage. However, the calibration path receives not only the attenuated transmitted signal but also many interference signals, leading to errors in the calibration calculations. Summary of the Invention
[0004] To address the aforementioned technical problems, this application provides a transmitter local oscillator leakage calibration method, comprising: The first DC vector value is obtained when the transmitter transmits the initial local oscillator leakage signal and in the first gain mode; The first gain mode is adjusted to the second gain mode to obtain the second DC vector value, and the first DC variable value is obtained based on the first DC vector value and the second DC vector value. The second DC variable value is obtained by superimposing the additional local oscillator leakage signal and the initial local oscillator leakage signal; Based on the first DC variable value and the second DC variable value, obtain the first ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal; The value of the additional local oscillator leakage signal is adjusted based on the first ratio so that the additional local oscillator leakage signal cancels out the initial local oscillator leakage signal.
[0005] In one embodiment, the first DC vector value and the second DC vector value include a local oscillator leakage signal component, a first type of interference component that is related to both local oscillator leakage and gain mode, a second type of interference component that is related to local oscillator leakage and independent of gain mode, and a third type of interference component that is independent of both local oscillator leakage and gain mode.
[0006] In one embodiment, obtaining the first DC variable value based on the first DC vector value and the second DC vector value includes: obtaining the difference between the first DC vector value and the second DC vector value as the first DC variable value.
[0007] In one embodiment, the first DC variable value and the second DC variable value include the difference between the local oscillator leakage signal components and the difference between the first type of interference components.
[0008] In one embodiment, obtaining the first ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal based on the first DC variable value and the second DC variable value includes: obtaining the difference between the second DC variable value and the first DC variable value as an intermediate value; the ratio of the intermediate value to the first DC variable value is equal to the first ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal.
[0009] In one embodiment, the intermediate value is related to the additional local oscillator leakage signal but not to the initial local oscillator leakage signal.
[0010] In one embodiment, obtaining the first DC vector value during transmitter transmission of the initial local oscillator leakage signal and in the first gain mode includes:
[0011] Where B1 represents the first DC vector value, L represents the initial local oscillator leakage signal, I represents the inherent interference signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, k2 represents the second type of interference coefficient, and k3 represents the third type of interference coefficient; Adjusting the first gain mode to the second gain mode and obtaining the second DC vector value includes:
[0012] Where B2 represents the second DC vector value, L represents the initial local oscillator leakage signal, I represents the inherent interference signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, k2 represents the second type of interference coefficient, k3 represents the third type of interference coefficient; a and a1 represent the mode influence coefficients.
[0013] In one embodiment, obtaining the first DC variable value based on the first DC vector value and the second DC vector value includes:
[0014] Where D1 represents the first DC variable value, B1 represents the first DC vector value, B2 represents the second DC vector value, L represents the initial local oscillator leakage signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, and a and a1 represent the mode influence coefficients. The second DC variable value is obtained by superimposing the additional local oscillator leakage signal with the initial local oscillator leakage signal, including:
[0015] Where D2 represents the second DC variable value, L represents the initial local oscillator leakage signal, O represents the additional local oscillator leakage signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, and a and a1 represent the mode influence coefficients.
[0016] In one embodiment, obtaining a first ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal based on a first DC variable value and a second DC variable value includes:
[0017] Where D1 represents the first DC variable value, D2 represents the second DC variable value, L represents the initial local oscillator leakage signal, O represents the additional local oscillator leakage signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, and a and a1 represent the mode influence coefficients.
[0018] This application also provides a transmitter local oscillator leakage calibration device, including a memory and a processor. The memory stores computer instructions that can be executed on the processor. When the processor executes the computer instructions, it performs the steps of the transmitter local oscillator leakage calibration method of any of the above embodiments.
[0019] According to the transmitter local oscillator leakage calibration method and apparatus provided by the present invention, by switching different modes, the corresponding DC vector values are read, and then the DC variable values are calculated using the DC vector values. Then, an additional local oscillator leakage signal is introduced to obtain the ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal, and the local oscillator leakage is calibrated and compensated. This avoids the influence of interference paths on calibration and improves calibration accuracy. Attached Figure Description
[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0021] Figure 1 This is a schematic diagram of interference caused by local oscillator leakage in the transmitter of this application; Figure 2 This is a flowchart of the transmitter local oscillator leakage calibration method of this application; Figure 3 This is a schematic diagram of the transmitter local oscillator leakage calibration method of this application. Detailed Implementation
[0022] To better understand the above-mentioned objectives, features, and advantages of this application, embodiments of this application will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.
[0023] Numerous specific details are set forth in the following description to provide a thorough understanding of this application, but this application may also be implemented in other ways than those described herein. Clearly, the embodiments described in the specification are only a portion of, and not all, of the embodiments of this application.
[0024] Reference Figure 1 As shown, in the calibration path between transmitter 110 and receiver 120, interference path ① represents leakage of the transmitter's local oscillator signal to the receiver, interference path ② represents leakage of the transmitter's local oscillator signal to the receiver's local oscillator, and interference paths ③ and ④ represent leakage of the transmitter's intermediate stage signal to the receiver. The existence of these interference paths leads to errors in calibration calculations and affects calibration accuracy.
[0025] To address the aforementioned problems, this application provides a transmitter local oscillator leakage calibration method, such as... Figure 2 As shown, it includes: Step S210: Obtain the first DC vector value while the transmitter is transmitting the initial local oscillator leakage signal and in the first gain mode; Step S220: Adjust the first gain mode to the second gain mode, obtain the second DC vector value, and obtain the first DC variable value based on the first DC vector value and the second DC vector value; Step S230: Obtain the second DC variable value by superimposing the additional local oscillator leakage signal and the initial local oscillator leakage signal; Step S240: Obtain the first ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal based on the first DC variable value and the second DC variable value; Step S250: Adjust the value of the additional local oscillator leakage signal based on the first ratio so that the additional local oscillator leakage signal cancels out the initial local oscillator leakage signal.
[0026] Execute step S210, refer to Figure 2 and Figure 3 As shown, the first DC vector value is obtained when the transmitter transmits the initial local oscillator leakage signal and in the first gain mode. Here, the initial local oscillator leakage signal L represents the unknown leakage signal that needs to be eliminated. The first gain mode is also called the default mode, in which the first DC vector value B1 is read.
[0027] In one embodiment, in Figure 1 In the calibration path shown, the local oscillator leakage signal of transmitter 110 and some interference signals are represented as a DC vector on the baseband of receiver 120. The first DC vector value B1 includes the local oscillator leakage signal component and various interference components. The interference components include first-type interference components related to both local oscillator leakage and gain mode, such as... Figure 1 The interference path ③ is shown in the image; the second type of interference component, which is related to local oscillator leakage and is independent of the gain mode, is as follows: Figure 1 The interference path ④ is shown in the image; and the third type of interference component, which is independent of both local oscillator leakage and gain mode, is shown in the image. Figure 1 The interference path ① is shown in the diagram. Therefore, the first DC vector B1 is represented as: (Equation 1) Where B1 represents the first DC vector value, L represents the initial local oscillator leakage signal, I represents the inherent interference signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, k2 represents the second type of interference coefficient, and k3 represents the third type of interference coefficient.
[0028] Next, proceed to step S220, referring to... Figure 2 and Figure 3 As shown, the first gain mode is adjusted to the second gain mode to obtain the second DC vector value, and the first DC variable value is obtained based on the first and second DC vector values. The initial local oscillator leakage signal L remains unchanged. The second gain mode is also called the low gain mode or special mode. In this case, the second DC vector value B2 is read.
[0029] In one embodiment, the second DC vector value B2 includes the same component types as the first DC vector value B1. The second DC vector value B2 also includes a local oscillator leakage signal component, a first type of interference component related to both local oscillator leakage and gain mode, a second type of interference component related to local oscillator leakage and independent of gain mode, and a third type of interference component independent of both local oscillator leakage and gain mode. Therefore, the second DC vector B2 is expressed as: (Equation 2) Where B2 represents the second DC vector value, L represents the initial local oscillator leakage signal, I represents the inherent interference signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, k2 represents the second type of interference coefficient, k3 represents the third type of interference coefficient; a and a1 represent the mode influence coefficients.
[0030] In one embodiment, obtaining the first DC variable value D1 based on the first DC vector value B1 and the second DC vector value B2 includes: obtaining the difference between the first DC vector value B1 and the second DC vector value B2 as the first DC variable value D1, also known as the DC increment value. Since the second and third type interference components are independent of the gain mode, the difference between the first DC vector value B1 and the second DC vector value B2 no longer includes the second and third type interference components (the differences are both 0). The first DC variable value D1 only includes the difference in the local oscillator leakage signal components and the difference in the first type interference components. Therefore, the first DC variable value D1 is expressed as: (Equation 3) Where D1 represents the first DC variable value, B1 represents the first DC vector value, B2 represents the second DC vector value, L represents the initial local oscillator leakage signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, and a and a1 represent the mode influence coefficients.
[0031] Next, proceed to step S230, referring to... Figure 2 and Figure 3 As shown, the second DC variable value D2 is obtained by superimposing the additional local oscillator leakage signal and the initial local oscillator leakage signal. The additional local oscillator leakage signal is represented by 0, and the superimposed local oscillator leakage signal is represented as (L+O). Therefore, when the local oscillator leakage signal is (L+O), the corresponding second DC variable value D2 is represented as: (Equation 4) Where D2 represents the second DC variable value, L represents the initial local oscillator leakage signal, O represents the additional local oscillator leakage signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, and a and a1 represent the mode influence coefficients.
[0032] It should be noted that since the second DC variable value D2 cannot be read directly, the third DC vector value B3 can be read when the local oscillator leakage signal is (L+O) and in the first gain mode, and the fourth DC vector value B4 can be read when the local oscillator leakage signal is (L+O) and in the second gain mode. The difference between the third DC vector value B3 and the fourth DC vector value B4 (B3-B4) is the second DC variable value D2.
[0033] Next, proceed to step S240, referring to... Figure 2 and Figure 3 As shown, the first ratio of the additional local oscillator leakage signal O to the initial local oscillator leakage signal L is obtained based on the first DC variable value D1 and the second DC variable value D2.
[0034] In one embodiment, obtaining the first ratio of the additional local oscillator leakage signal O to the initial local oscillator leakage signal L based on the first DC variable value D1, the second DC variable value D2, and the additional local oscillator leakage signal O includes: obtaining the difference (D2-D1) between the second DC variable value D2 and the first DC variable value D1 as an intermediate value, wherein the intermediate value (D2-D1) is related to the additional local oscillator leakage signal O but not to the initial local oscillator leakage signal L. Further, the ratio of the intermediate value (D2-D1) to the first DC variable value D1 is equal to the first ratio of the additional local oscillator leakage signal O to the initial local oscillator leakage signal L. (Equation 5) Where D1 represents the first DC variable value, D2 represents the second DC variable value, L represents the initial local oscillator leakage signal, O represents the additional local oscillator leakage signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, and a and a1 represent the mode influence coefficients.
[0035] Next, proceed to step S250, referring to... Figure 2 and Figure 3 As shown, the value of the additional local oscillator leakage signal is adjusted based on the first ratio so that the additional local oscillator leakage signal cancels out the initial local oscillator leakage signal.
[0036] In one embodiment, the value of the additional local oscillator leakage signal is adjusted based on a first ratio so that the value of the additional local oscillator leakage signal is equal to and opposite in direction to the value of the initial local oscillator leakage signal, thereby canceling out the initial local oscillator leakage signal and completing the compensation.
[0037] Thus, the DC variable value is first obtained by reading the DC vector value. Then, the unknown initial local oscillator leakage signal L can be obtained by comparing the DC variable value with the input (i.e., the additional local oscillator leakage signal O introduced by the known control code), or only the ratio of the additional local oscillator leakage signal O to the initial local oscillator leakage signal L can be obtained. This ratio can be used to deduce the control code corresponding to the ideal compensation state, thereby calibrating and compensating for the transmitter's local oscillator leakage. (Refer to...) Figure 3 As shown, after applying the compensation value, the calibration path configuration can be further optimized and calibration can be performed again to improve calibration accuracy through iteration.
[0038] This application also provides a transmitter local oscillator leakage calibration device, including a memory and a processor. The memory stores computer instructions that can be executed on the processor. When the processor executes the computer instructions, it performs the steps of the transmitter local oscillator leakage calibration method as described above.
[0039] In one embodiment, the memory stores programs for implementing corresponding steps in the transmitter local oscillator leakage calibration method according to embodiments of the present application. The processor is configured to run the programs stored in the memory to perform the corresponding steps of the transmitter local oscillator leakage calibration method according to embodiments of the present application.
[0040] Furthermore, according to embodiments of this application, a storage medium is also provided, on which program instructions are stored. When executed by a computer or processor, these program instructions are used to perform corresponding steps of the transmitter local oscillator leakage calibration method of this application. The storage medium may, for example, include a memory card of a smartphone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.
[0041] According to the transmitter local oscillator leakage calibration method, apparatus and storage medium provided by the present invention, by switching different modes, the corresponding DC vector value is read, and then the DC variable value is calculated through the DC vector value. Then, an additional local oscillator leakage signal is introduced to obtain the ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal, and the local oscillator leakage is calibrated and compensated, thus avoiding the influence of interference path on calibration and improving calibration accuracy.
[0042] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to the process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0043] The above descriptions are merely embodiments of this application, which enable those skilled in the art to understand and implement this application. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
Claims
1. A transmitter local oscillator leakage calibration method, characterized in that, include: The first DC vector value is obtained when the transmitter transmits the initial local oscillator leakage signal and in the first gain mode; The first gain mode is adjusted to the second gain mode to obtain the second DC vector value, and the first DC variable value is obtained based on the first DC vector value and the second DC vector value. The second DC variable value is obtained by superimposing the additional local oscillator leakage signal with the local oscillator leakage signal; Based on the first DC variable value and the second DC variable value, obtain a first ratio between the additional local oscillator leakage signal and the initial local oscillator leakage signal; The value of the additional local oscillator leakage signal is adjusted based on the first ratio so that the additional local oscillator leakage signal cancels out the initial local oscillator leakage signal.
2. The transmitter local oscillator leakage calibration method according to claim 1, characterized in that, The first DC vector value and the second DC vector value include a local oscillator leakage signal component, a first type of interference component that is related to both local oscillator leakage and gain mode, a second type of interference component that is related to local oscillator leakage and is independent of gain mode, and a third type of interference component that is independent of both local oscillator leakage and gain mode.
3. The transmitter local oscillator leakage calibration method according to claim 2, characterized in that, Obtaining the first DC variable value based on the first DC vector value and the second DC vector value includes: The difference between the first DC vector value and the second DC vector value is obtained and used as the first DC variable value.
4. The transmitter local oscillator leakage calibration method according to claim 2, characterized in that, The first DC variable value and the second DC variable value include the difference in the local oscillator leakage signal component and the difference in the first type of interference component.
5. The transmitter local oscillator leakage calibration method according to claim 1, characterized in that, Obtaining the first ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal based on the first DC variable value and the second DC variable value includes: The difference between the second DC variable value and the first DC variable value is obtained as an intermediate value; The ratio of the intermediate value to the first DC variable value is equal to the first ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal.
6. The transmitter local oscillator leakage calibration method according to claim 5, characterized in that, The intermediate value is related to the additional local oscillator leakage signal but is not related to the initial local oscillator leakage signal.
7. The transmitter local oscillator leakage calibration method according to claim 1, characterized in that, Obtaining the first DC vector value during the transmitter's initial local oscillator leakage signal transmission and in the first gain mode includes: Where B1 represents the first DC vector value, L represents the initial local oscillator leakage signal, I represents the inherent interference signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, k2 represents the second type of interference coefficient, and k3 represents the third type of interference coefficient; Adjusting the first gain mode to the second gain mode and obtaining the second DC vector value includes: Where B2 represents the second DC vector value, L represents the initial local oscillator leakage signal, I represents the inherent interference signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, k2 represents the second type of interference coefficient, k3 represents the third type of interference coefficient; a and a1 represent the mode influence coefficients.
8. The transmitter local oscillator leakage calibration method according to claim 7, characterized in that, Obtaining the first DC variable value based on the first DC vector value and the second DC vector value includes: Where D1 represents the first DC variable value, B1 represents the first DC vector value, B2 represents the second DC vector value, L represents the initial local oscillator leakage signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, and a and a1 represent the mode influence coefficients. The second DC variable value is obtained by superimposing the additional local oscillator leakage signal with the initial local oscillator leakage signal, including: Where D2 represents the second DC variable value, L represents the initial local oscillator leakage signal, O represents the additional local oscillator leakage signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, and a and a1 represent the mode influence coefficients.
9. The transmitter local oscillator leakage calibration method according to claim 8, characterized in that, Obtaining the first ratio of the additional local oscillator leakage signal to the initial local oscillator leakage signal based on the first DC variable value and the second DC variable value includes: Where D1 represents the first DC variable value, D2 represents the second DC variable value, L represents the initial local oscillator leakage signal, O represents the additional local oscillator leakage signal, k represents the signal gain coefficient, k1 represents the first type of interference coefficient, and a and a1 represent the mode influence coefficients.
10. A transmitter local oscillator leakage calibration device, comprising a memory and a processor, wherein the memory stores computer instructions executable on the processor, characterized in that, When the processor executes the computer instructions, it performs the steps of the transmitter local oscillator leakage calibration method according to any one of claims 1-9.