A method for calibrating front-end scattering parameters and its user equipment

Abstract

This invention provides a method for calibrating front-end scattering parameters and a user equipment using the method. The method for calibrating front-end scattering parameters includes the following steps: measuring at least three coupler reflection coefficients under at least three different tuner measurement control words; obtaining multiple tuner scattering parameters corresponding to these tuner measurement control words; and calibrating the front-end scattering parameters based on the at least three coupler reflection coefficients and these tuner scattering parameters. This method utilizes the tuner for calibration, eliminating the need for additional calibration kits and setting the tuner to a low-isolation mode. Therefore, this method enables signal transmission during calibration, allowing front-end calibration to occur simultaneously with the normal operation of the mobile device.

Description

Technical Field

[0001] This invention relates to the field of antenna parameter measurement technology, and in particular to a method for calibrating front-end scattering parameters and its user equipment. Background Technology

[0002] Precise scene detection capabilities play a crucial role in improving antenna performance. The accuracy of scene detection is closely related to various mobile device technologies, including antenna tuning and transmit power control. Impedance measurement is an effective method for antenna-related technologies, in which front-end (FE) calibration is a key component.

[0003] Traditionally, calibrating front-end scattering parameters (S2P) requires either a built-in or external calibration kit. In transmitter (Tx) systems, calibrating the scattering parameters of the components requires removing the antenna or setting the output to high isolation mode to avoid measurement errors caused by the current antenna state. This can either prevent the transmitter from transmitting signals correctly or require PCB rework. Summary of the Invention

[0004] In view of this, the present invention provides a method for calibrating front-end scattering parameters and a user equipment thereof, which can calibrate front-end scattering parameters more accurately without the need for calibration kits. Furthermore, the present invention does not require the removal of the antenna or setting the output to high isolation mode when calibrating front-end scattering parameters, and the antenna and related systems can function normally.

[0005] This invention relates to a method for calibrating front-end scattering parameters and a user equipment using the method. The calibration of the front-end scattering parameters utilizes forward and reverse radio frequency signals. A novel calibration algorithm and procedure enable accurate calibration of front-end scattering parameter values ​​in environments with arbitrary unknown antenna reflectivity, without requiring the transmitter to be set to high isolation mode. The method utilizes a tuner for calibration, eliminating the need for additional calibration kits and setting the tuner to low isolation mode. Therefore, the method allows signal transmission during calibration, enabling simultaneous front-end calibration and normal operation of the mobile device. This calibration process allows real-time measurement of front-end scattering parameters in network-allocated frequency scenarios, reducing the impact of factors such as component differences and temperature variations. The method involves switching between at least three tuner states without affecting signal transmission, thereby ensuring accurate S-parameter (scattering parameter) calibration without using the antenna reflectivity.

[0006] According to one embodiment, a method for calibrating front-end scattering parameters is provided. The method includes the following steps: measuring at least three coupler reflection coefficients under at least three different tuner measurement control words; obtaining multiple tuner scattering parameters corresponding to the tuner measurement control words; and calibrating the front-end scattering parameters based on the at least three coupler reflection coefficients and the tuner scattering parameters.

[0007] Furthermore, the reflection coefficients of at least three couplers are measured offline, in real-time, or in a hybrid mode to ensure accurate measurements.

[0008] Furthermore, the switching between the tuner's measurement control words is controlled by multiple single-instruction control signals, or by multiple-instruction control signals, to ensure accurate measurements.

[0009] Furthermore, both the single instruction control signal and the multiple instruction control signal are Mobile Industrial Processor Interface (MIPI) signals to enable accurate measurement.

[0010] Furthermore, the reflection coefficients of the at least three couplers are measured via a feedback path, and the RF signal transmission paths in both the RF front-end circuitry (RFFE) and the transmit (Tx) modem remain fixed during the measurement of the at least three coupler reflection coefficients to ensure accurate measurement.

[0011] Furthermore, when measuring the reflection coefficients of the at least three couplers in real time, the measurement time for the reflection coefficients of the at least three couplers is within 0.1 seconds, in order to perform accurate measurements.

[0012] Furthermore, the reflection coefficients of at least three couplers are measured under the condition that the antenna reflection coefficient is constant, in order to make accurate measurements.

[0013] Furthermore, when the input port of the RF front-end circuit (RFFE) is connected to the coupler and the output port of the RFFE is connected to the tuner, the reflection coefficients of each of the at least three couplers are measured to ensure accurate measurement.

[0014] Furthermore, this also includes: calibrating the antenna reflection coefficient based on the calibrated front-end scattering parameters to ensure accurate measurements, and calibrating the antenna reflection coefficient using the accurately calibrated front-end scattering parameters.

[0015] Furthermore, in the step of calibrating the front-end scattering parameters, the front-end scattering parameters are calibrated in the following way: ; , and The reflection coefficients of the three couplers were measured under three different tuner measurement control words; ; ; ; It is the reflection coefficient of the RFFE input port, which represents the proportion of signal waves entering the RFFE input port that are reflected back to the RFFE input port; It is the transmission coefficient from the RFFE input port to the RFFE output port, representing the proportion of the signal wave entering the RFFE input port that is transmitted to the RFFE output port; It is the transmission coefficient from the RFFE output port to the RFFE input port, representing the proportion of the signal wave entering the RFFE output port that is transmitted to the RFFE input port; It is the reflection coefficient of the RFFE output port, which represents the proportion of the signal wave entering the RFFE output port that is reflected back to the RFFE output port; , , , , , , , , , , and These are the tuner scattering parameters corresponding to different tuner measurement control words.

[0016] According to another embodiment, a user equipment is provided. The user equipment includes an antenna, a tuner, an RF front-end circuit (RFFE), a coupler, a transmitting (Tx) modem, and a feedback path unit. The tuner is connected to the antenna. The tuner is used to switch at least three different tuner measurement control words. The RFFE is connected to the tuner. The coupler is connected to the RFFE. The transmitting (Tx) modem is connected to the coupler. The feedback path unit is connected to the RFFE. The feedback path unit is used to measure at least three coupler reflection coefficients under at least three different tuner measurement control words, obtain multiple tuner scattering parameters corresponding to the tuner measurement control words, and calibrate front-end scattering parameters based on the at least three coupler reflection coefficients and the tuner scattering parameters.

[0017] Furthermore, the user equipment is used to perform any of the steps described above.

[0018] The innovative method and user equipment of this invention enable precise calibration of front-end scattering parameters in environments with arbitrary unknown antenna reflectivity, without requiring the transmitter to be set to high isolation mode. This method utilizes a tuner for calibration, eliminating the need for additional calibration kits and setting the tuner to low isolation mode. Therefore, the method allows signal transmission during calibration, enabling simultaneous front-end calibration and normal operation of the mobile device. This calibration process can measure front-end scattering parameters in real-time within network-allocated frequency scenarios, thereby reducing the impact of factors such as component differences and temperature variations. The method involves switching between at least three tuner states without affecting signal transmission, ensuring accurate scattering parameter calibration without using the antenna reflectivity. Attached Figure Description

[0019] Figure 1 A schematic diagram of a user equipment according to an embodiment of the present invention is shown.

[0020] Figure 2 Several tuner scattering parameters according to an embodiment of the present invention are shown.

[0021] Figure 3 Several front-end scattering parameters according to an embodiment of the present invention are shown.

[0022] Figure 4 A method for measuring tuner scattering parameters according to an embodiment of the present invention is shown.

[0023] Figure 5 A method for selecting a tuner measurement control word according to an embodiment of the present invention is shown.

[0024] Figure 6 A flowchart of a front-end scattering parameter calibration method according to an embodiment of the present invention is shown.

[0025] Figure 7 It shows Figure 6 The steps in the process.

[0026] Figure 8 A flowchart of a front-end scattering parameter calibration method according to another embodiment of the present invention is shown. Figure 9 illustrates the steps in Figure 8.

[0027] Figure 10 illustrates the hardware features for performing automatic tuner measurement control word switching according to an embodiment of the present invention.

[0028] Figure 11 illustrates clock calibration for automatic tuner measurement control word switching according to an embodiment of the present invention. Detailed Implementation

[0029] The following description is intended to illustrate the general principles of the invention and should not be considered as a limiting description. The scope of the invention is best determined by referring to the appended claims.

[0030] The following description is for illustrative purposes only and should not be construed as limiting. The scope of the invention is best determined by reference to the appended claims. In embodiments of the invention, when a component or layer is referred to as being “located,” “connected to,” or “coupled to” another component or layer, it may be directly located, connected to, or coupled to that other component or layer, or there may be intermediate components or layers. Conversely, when a component is referred to as being “directly located,” “directly connected to,” or “directly coupled to” another component or layer, there are no intermediate components or layers. The same numbers always refer to the same component. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. “Directly above” or “directly below” may indicate that the projections of two or more of them at least partially overlap, while “not directly above” or “directly below” may indicate that the projections of two or more of them do not overlap at all. The same numbers refer to the same component throughout the document. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0031] Please see Figure 1 The figure illustrates a schematic diagram of a user equipment (or user device) 100 according to an embodiment of the present invention. The user equipment 100 may be, for example, a mobile phone, a laptop computer, a modem (modulator-demodulator) chip, or a communication chip embedded in a mobile device, robot, and / or vehicle.

[0032] User equipment 100 includes, for example, an antenna 110, a tuner 120, an RF front-end circuit (RFFE) 130, a coupler 140, a transmitting (Tx) modem 150, and a feedback path unit 160. In user equipment 100, antenna 110 serves as an interface between electromagnetic waves in the air and electrical signals in the circuit. Antenna 110 can be, for example, but not limited to, a dipole antenna, a monopole antenna, a patch antenna, a helical antenna, a Yagi antenna, and / or a phased array antenna. A dipole antenna consists of two metal rods. A monopole antenna has a single conductor and is typically mounted on a ground plane. A patch antenna is flat and used in mobile devices and / or IoT devices. A helical antenna is coil-shaped and suitable for circular polarization. A Yagi antenna is directional and used for television and point-to-point links. A phased array antenna has beam control capabilities and is used in radar and 5G systems.

[0033] Tuner 120 may be coupled to antenna 110. Tuner 120 may be the first stage after antenna 110. Tuner 120 is used to select a specific frequency or channel from the received broadband radio frequency signal. It adjusts the receiving circuitry to match the desired signal frequency, typically including filtering and amplification functions. Tuner 120 may be an analog tuner, a digital tuner, a broadband tuner, and / or a closed-loop tuner, but is not limited to these. Analog tuners use variable capacitors or inductors for manual tuning. Digital tuners are electronically controlled and use a phase-locked loop (PLL) for precise tuning. Broadband tuners can cover a large frequency range without switching components. Closed-loop tuners can be adjusted in real time or continuously based on feedback from a signal quality indicator.

[0034] The RF front-end circuit 130 can be connected to the tuner 120. The tuner 120 can be connected between the antenna 110 and the RF front-end circuit 130. The RF front-end circuit 130 processes the raw RF signal by filtering, amplifying, and converting the raw RF signal to intermediate frequency (IF) or baseband for demodulation. The RF front-end circuit 130 may include a low-noise amplifier (LNA), a bandpass filter, a mixer, and / or a switch / duplexer. The LNA is used to amplify weak signals and minimize noise. The bandpass filter is used to select the desired frequency band and suppress out-of-band noise. The mixer is used to convert the RF signal to a lower frequency (LF) by mixing it with the local oscillator signal. The switch / duplexer is used to separate the transmit (Tx) and receive (Rx) paths, especially in full-duplex systems.

[0035] The RF front-end circuit 130 can be, for example, but not limited to, a discrete RF front-end, an integrated front-end module (FEM), and / or a software-defined RF front-end. A discrete RF front-end consists of independent components and can be customized. An integrated front-end module is a compact module widely used in devices such as smartphones and Wi-Fi. A software-defined RF front-end supports dynamic reconfiguration for different frequency bands and standards.

[0036] Coupler 140 is a passive radio frequency component used to extract a small portion of the signal from the transmission path without interfering with the main signal flow. It is commonly used for power monitoring, signal sampling, and feedback loops. Coupler 140 is typically used to monitor transmit or reflected power, provide feedback to closed-loop systems (e.g., power control, beamforming), or protect components such as power amplifiers (PAs) by detecting mismatch / reflection. Coupler 140 can be a directional coupler, hybrid coupler, bidirectional coupler, or sampling coupler, but is not limited to these.

[0037] The transmit modem 150 is used to demodulate the input signal, extracting digital data from the analog waveform. It is also responsible for error correction, synchronization, and decoding. The Tx modem 150 includes, but is not limited to, ASK / FSK / PSK demodulators, QAM demodulators, OFDM demodulators, and / or software-defined modems. ASK / FSK / PSK demodulators are used in simple digital systems such as RFID or low-power IoT. QAM demodulators are common in high-speed data systems such as LTE and Wi-Fi. OFDM demodulators are used in modern broadband systems (4G / 5G, Wi-Fi). Software-defined modems are implemented using DSPs or FPGAs and support multiple modulation types.

[0038] Feedback path unit 160 is a circuit path used to send signal samples (typically from a coupler) back to the previous stage. Feedback path unit 160 is typically used for calibration, correction, gain control, impedance tuning, or beamforming adjustment. The hardware implementation of feedback path unit 160 can take many forms, including but not limited to a monitoring receiver (MRx). Feedback path unit 160 can be an analog feedback path unit, a digital feedback path unit, a closed-loop feedback path unit, or an open-loop feedback path unit, but is not limited to these.

[0039] As shown in Figure 1, there is an antenna reflection coefficient. Front reflection coefficient Tuner reflection coefficient and coupler reflection coefficient In the following text, these can also be written as antenna reflection coefficient Γ_Ant, front-end reflection coefficient Γ_FE, tuner reflection coefficient Γ_in, and coupler reflection coefficient Г_MRx.

[0040] The antenna reflection coefficient Γ_Ant measures the amount of incident signal reflected due to impedance mismatch between the antenna and the connecting circuitry (typically the RF front-end). It is a key indicator of the antenna's power transmission efficiency to the system. A lower reflection coefficient Γ_Ant indicates good impedance matching (minimal signal loss). A higher reflection coefficient Γ_Ant indicates poor matching (more signal is reflected).

[0041] The front-end reflection coefficient Γ_FE represents the amount of signal reflected at the input of the RF front-end circuit 130 due to impedance mismatch with antenna 110 or tuner 120. Even if antenna 110 is well designed, impedance mismatch in the RF front-end circuit 130 will still degrade system performance.

[0042] The tuner reflection coefficient Γ_in refers to the reflection coefficient at the second tuner port P2. The tuner reflection coefficient Γ_in represents the compensation effect of tuner 120 in the case of mismatch.

[0043] The coupler reflection coefficient Γ_MRx refers to the reflection coefficient at coupler 140. The coupler reflection coefficient Γ_MRx represents the impedance mismatch between coupler 140 and the listening receiver (MRx).

[0044] The receiving modem 140 includes a software (SW) control module 141. The SW control module 141 is a hardware implementation controlled by software and can be implemented in various ways, including but not limited to Mobile Industry Processor Interface Radio Frequency Front-End (MIPIRFFE).

[0045] The tuner 120 includes a state machine module 121. The state machine module 121 is a hardware implementation of the state machine, which can be implemented in various ways, including but not limited to microcontrollers, complex programmable logic devices (CPLDs) and field-programmable gate arrays (FPGAs).

[0046] In this invention, tuner 120 can be used to calibrate multiple front-end scattering parameters. , , , (As shown in Figure 3). This invention provides an algorithm for calibrating the front-end scattering parameters of the radio frequency front-end (RFFE) 130 using tuner 120 under arbitrary unknown antenna impedance. , , , .

[0047] Furthermore, this invention also provides an algorithm for using front-end scattering parameters. , , , In this case, the antenna reflection coefficient Γ_Ant is calibrated using tuner 120.

[0048] Furthermore, this invention also provides hardware design guidelines for tuner 120. The proposed method is used to simultaneously calibrate front-end scattering parameters using the transmitted signal without affecting signal transmission. , , , .

[0049] To calibrate front-end scattering parameters in real time , , , The required data report includes at least three coupler reflection coefficients Γ_MRx and tuner scattering parameters. , , , (As shown in Figure 2), these parameters were measured at at least three different tuner measurement control words (CWx). Tuner scattering parameters , , , The superscript "x" indicates the tuner measurement control word CWx.

[0050] Under different tuner measurement control words CWx, the feedback path unit 160 measures at least three coupler reflection coefficients Γ_MRx. Under different tuner measurement control words CWx, the tuner scattering parameters... , , , The scattering parameters can be estimated through offline simulation or by measurement using a device such as a vector network analyzer (VNA). In one embodiment, referring to Figures 2 and 5, the tuner 120 can be measured before being coupled to the antenna 110 and the RF front-end circuitry 130 to obtain the scattering parameters. , , , In some embodiments, after the tuner 120 is coupled to the antenna 110 and the RF front-end circuitry 130, the feedback path unit 160 measures at least three coupler reflection coefficients Γ_MRx at different tuner measurement control words CWx.

[0051] To prevent changes in the internal channels, during reception, the RF signal transmission paths in the RF front-end circuit 130 and the transmit modem 150 should remain fixed for all tuner measurement control words CWx in the feedback path.

[0052] To prevent changes in the antenna reflection coefficient Γ_Ant, in real-time scenarios, the coupler reflection coefficient Γ_MRx, measured by the tuner measurement control word feedback path, should be measured within 0.1 seconds (e.g., , , and The coupler reflection coefficient Γ_MRx is measured by the feedback path unit 160 under different tuner measurement control words CWx.

[0053] Please see Figure 2 The figure shows tuner scattering parameters according to an embodiment of the present invention. , , , Tuner scattering parameters , , , The superscript "x" indicates the tuner measurement control word CWx. For example, tuner scattering parameters. , , , These are the reflection coefficient and transmission coefficient of tuner 120 when tuner input port P21 and tuner output port P22 are connected to a 50Ω (Z_0) and tuner 120 is set to the tuner measurement control word CW1; and the tuner scattering parameters. , , , These are the reflection coefficient and transmission coefficient of tuner 120 when tuner input port P21 and tuner output port P22 are connected to 50Ω (Z_0) and tuner 120 is set to tuner measurement control word CW2. Tuner scattering parameters. , , , These are the reflection coefficient and transmission coefficient of tuner 120 when tuner input port P21 and tuner output port P22 are connected to 50Ω (Z_0) resistors, and tuner 120 is configured to measure the tuner measurement control word CW3. In some embodiments, the value of Z_0 is 50Ω for illustrative purposes only. Z_0 can be any resistance value, not limited to 50Ω. Z_0 can be other predetermined values.

[0054] Tuner scattering parameters ( , or ) is the reflection coefficient at tuner input port P21, representing the proportion of the wave entering tuner input port P21 that is reflected back to tuner input port P21.

[0055] Tuner scattering parameters ( , or ) is the transmission coefficient from tuner input port P21 to tuner output port P22, representing the proportion of the signal entering tuner input port P21 that is transmitted to tuner output port P22.

[0056] Tuner scattering parameters ( , or ) is the transmission coefficient from tuner output port P22 to tuner input port P21, representing the proportion of the signal entering tuner output port P22 that is transmitted to port P21.

[0057] Tuner scattering parameters ( , or ) is the reflection coefficient at tuner output port P22, representing the proportion of the wave entering tuner output port P22 that is reflected back to tuner output port P22.

[0058] Please refer to Figure 3, which shows the front-end scattering parameters according to an embodiment of the present invention. , , , Front-end scattering parameters , , , These are the reflection coefficient and transmission coefficient of RFFE 130 when its input port P30 and output port P31 are connected to 50 Ω (Z_0).

[0059] The front-end scattering parameter e_00 is the reflection coefficient at the RFFE input port P30 of the RFFE 130, representing the proportion of waves entering the RFFE 130 input port P30 that are reflected back to the RFFE 130 input port P30.

[0060] Front-end scattering parameters It is the transmission coefficient from RFFE input port P30 to RFFE output port P31 of RFFE 130, representing the proportion of the wave entering RFFE 130 input port P30 that is transmitted to RFFE 130 output port P31.

[0061] Front-end scattering parameters This is the transmission coefficient from the output port P31 of RFFE 130 to the input port P30 of RFFE 130. It represents the proportion of the wave entering the output port P31 of RFFE 130 that is transmitted to the output port P31 of RFFE 130. The signal transmitted to the input port P30 of RFFE 130 is the input port P30 of RFFE 130.

[0062] Front-end scattering parameters It is the reflection coefficient at RFFE 130 output port P31, representing the proportion of the signal entering RFFE 130 output port P31 that is reflected back to RFFE 130 output port P31.

[0063] Front-end scattering parameters Equivalent to the front-end scattering parameter e_10, the front-end scattering parameters e_00, e_10, e_01, and e_11 can be considered as three variables.

[0064] Please refer to Figure 4, which shows the tuner scattering parameters according to an embodiment of the present invention. , , , , , , , , , , , The measurement results. Tuner scattering parameters. , , , , , , , , , , , Estimation can be performed through offline simulation or by using devices such as, but not limited to, the Vector Network Analyzer (VNA) 920.

[0065] Measuring tuner scattering parameters , , , , , , , , , , , One example involves disconnecting the tuner 120 from the RF front-end circuitry 130. Cables CB1 and CB2 of the antenna 110 are soldered to the tuner input port P21 and output port P22 of the VNA 920, respectively; and the tuner's scattering parameters are measured. , , , , , , , , , , , In some embodiments (see Figures 2 and 5), tuner 120 can be configured to perform measurements. Tuner 120 can perform measurements in different states (e.g., using tuner measurement control words CW1, CW2, and CW3) to obtain corresponding scattering parameters. For example, tuner 120 can perform measurements to obtain scattering parameters before coupling to antenna 110 and RF front-end circuitry 130. In some embodiments, tuner 120 is first set to a first state via tuner measurement control word CW1 to measure and obtain scattering parameters. , , , Then, the scattering parameters are measured and obtained by setting the tuner measurement control word CW2 to the second state. , , , Then, the tuner 120 is set to the third state via the tuner measurement control word CW3 to measure and obtain the scattering parameters. , , , After completing these steps, tuner 120 is coupled to antenna 110 and RF front-end circuitry 130. Subsequently, tuner 120 is set to a first state via tuner measurement control word CW1, modem 150 transmits signals, and coupler reflection coefficient is measured (and / or calculated) as follows. Next, the tuner 120 is set to the second state via the tuner measurement control word CW2, the transmitting modem 150 transmits a signal, and the coupler reflection coefficient is measured (and / or calculated) as follows. Next, the tuner 120 is set to the third state via the tuner measurement control word CW3, the transmitting modem 150 transmits a signal, and the coupler reflection coefficient is measured (and / or calculated) using the following method. In some embodiments, the three signals transmitted by the transmitting modem 150 are known signals.

[0066] To measure tuner scattering parameters , , The known signal is sent to the tuner 120 via cable CB1, and the reflected signal is measured via cable CB1.

[0067] To measure tuner scattering parameters , , The known signal is sent to tuner 120 via cable CB1, and the reflected signal is measured via cable CB2.

[0068] To measure tuner scattering parameters , , The known signal is sent to the tuner 120 via cable CB2, and the reflected signal is measured via cable CB1.

[0069] To measure tuner scattering parameters , , The known signal is sent to the tuner 120 via cable CB2, and the reflected signal is measured via cable CB2.

[0070] Based on the above methods, tuner scattering can be measured offline. , , , , , , , , , , , .

[0071] As shown in Figure 1, the coupler reflection coefficient Γ_MRx is estimated as follows. The coupler reflection coefficient Γ_MRx represents the ratio of the forward RF signal to the reverse RF signal measured by the feedback path unit 160. The impedance of the feedback path unit 160 is 50 Ω. For example, the coupler reflection coefficient Γ_MRx can be obtained by the following formula (1).

[0072] (1); Coupler 140 separates the forward radio frequency signal RFf (or incident signal) and the reverse radio frequency signal RFr (or reflected signal). The forward radio frequency signal RFf propagates to the radio frequency front end (RFFE) 130, while the reflected forward radio frequency signal RFf from RFFE 130 is coupled to the coupling port P43.

[0073] The feedback path unit 160, connected to the coupling port P43, measures the amplitude and phase of the reflected positive radio frequency signal RFf.

[0074] The following describes the front-end scattering parameters. , , , The calibration algorithm. Based on hardware capabilities and user requirements, the front-end scattering parameters... , , , The calibration algorithm can be executed offline, in real time, or in a hybrid mode (e.g., a hybrid mode of offline and real time).

[0075] During calibration, the antenna reflection coefficient Γ_Ant is constant. Under the tuner measurement control word CWa, the antenna reflection coefficient... It can be expressed by the following formulas (2) to (5), where the coupler reflection coefficient Under the tuner measurement control word CWa, the tuner scattering parameters are... The result is obtained by de-embedding.

[0076] (2); (3); (4); (5); x is the determinant of the RFFE scattering parameters ( Alternatively, x can represent the determinant of the scattering parameter matrix E, as shown in equation (6).

[0077] (6); y is the front-end scattering parameter at the RFFE input port P30 of the RFFE 130. .

[0078] z is the negative front-end scattering parameter at the RFFE output port P31 of the RFFE 130. .

[0079] The total number of calibration settings can be any value greater than 2. Based on the fact that the antenna reflection coefficient Γ_Ant remains constant during calibration, the antenna reflection coefficient is measured under the tuner control word CWa (e.g., CW1, CW2, CW3, etc.). Antenna reflection coefficient under tuner measurement control word CWb It satisfies the following formula (7).

[0080] (7); Equation (7) is equivalent to the following equation (8).

[0081] (8); To improve calibration accuracy, the coupler reflection coefficient Γ_MRx can be measured under different tuner measurement control words, and the front-end scattering parameters can be calibrated using a set of equations. , , , For example, the following equation (9) can be represented using three different tuner measurement control words CW1, CW2, and CW3.

[0082] (9); By solving the simultaneous equations (9), x, y, and z can be obtained, and then the front-end scattering parameters can be obtained through equations (3) to (5). , , , .

[0083] Furthermore, by solving the front-end scattering parameters , , , The antenna reflection coefficient Γ_Ant can be derived using the following set of equations (10).

[0084] (10); Please refer to Figure 5, which illustrates a method for selecting tuner measurement control words CW1, CW2, and CW3 according to an embodiment of the present invention. The selection of tuner measurement control words CW1, CW2, and CW3 is highly dependent on the design of the tuner RF hardware. To prevent degradation of received signal quality, it is recommended (but not limited to) selecting tuner measurement control words CW1, CW2, and CW3 with insertion loss below 1 dB.

[0085] To ensure the linear independence of the tuner measurement control words CW1, CW2 and CW3, firstly, the selected tuner measurement control words CW1, CW2 and CW3 should satisfy that the determinant Δ of the tuner scattering parameter is not equal to 0, as shown in equation (11) below.

[0086] (11); Secondly, the selected tuner measurement control words CW1, CW2, and CW3 should satisfy that the tuner reflection coefficient difference d under the supported antenna reflection coefficient Γ_Ant is not equal to 0, as shown in the following formula (12).

[0087] (12); For example, tuner 120 can consist of switch S1 and three variable capacitors D1, D2, and D3. When switch S1 is on and variable capacitors D1, D2, and D3 are off or deactivated (or remain low), tuner 120 is controlled by tuner measurement control word CW1. When switch S1 is off, variable capacitor D1 is on or activated (or remains high), and variable capacitors D2 and D3 are off or deactivated (or remain low), tuner 120 is controlled by tuner measurement control word CW2. When switch S1 is off, variable capacitors D1 and D3 are off or deactivated (or remain low), and variable capacitor D2 is on or activated (or remains high), tuner 120 is controlled by tuner measurement control word CW3.

[0088] Please refer to Figures 6 and 7. Figure 6 illustrates the calibration of front-end scattering parameters according to an embodiment of the present invention. , , , The flowchart of the method is shown in Figure 7. Figure 7 illustrates the steps in Figure 6. Figure 6 shows the calibration of the front-end scattering parameters. , , , The method includes steps S110 to S150. Step S110 includes steps S111 to S116.

[0089] In step S110, as shown in Figure 7, the feedback path unit 160 measures the reflection coefficients of at least three couplers. , , At least three couplers reflection coefficients , , Measurements are performed under different tuner measurement control words CW1, CW2, and CW3. In the embodiment shown in Figure 6, multiple single-instruction control signals S11, S12, and S13 (e.g., Mobile Industry Processor Interface (MIPI) signals) are sent to trigger different tuner measurement control words CW1, CW2, and CW3. Specifically, single-instruction control signal S11 triggers a switch to tuner measurement control word CW1; single-instruction control signal S12 triggers a switch to tuner measurement control word CW2; and single-instruction control signal S13 triggers a switch to tuner measurement control word CW3.

[0090] Step S110 includes steps S111 to S116. As shown in FIG7, in step S111, the software control module 151 of the transmitting modem 150 sends a single command control signal S11 (or S12, S13) to the tuner 120. That is, a single command control signal is sent.

[0091] Next, as shown in Figure 7, in step S112, the state machine module 121 of the tuner 120 writes the tuner measurement control word CW1 (or CW2, CW3) into the register.

[0092] Then, as shown in Figure 7, in step S113, tuner 120 switches to the standby state and waits for steps S114 and S115 to complete. That is, it switches to the next tuner measurement control word.

[0093] Meanwhile, as shown in Figure 7, in step S114, the transmitting modem 150 stops transmitting signals and waits for the tuner to stabilize for a period of time (e.g., Å microseconds). That is, it pauses signal transmission and waits for the tuner to stabilize.

[0094] Then, as shown in Figure 7, in step S115, the feedback path unit 160 measures the reverse RF signal RFr and the forward RF signal RFf, with a measurement period of B microseconds. That is, the reverse RF signal and the forward RF signal are measured within the measurement period.

[0095] Then, as shown in Figure 7, in step S116, the feedback path unit 160 determines whether the measurement of the reverse RF signal RFr and the forward RF signal RFf of all tuner measurement control words CW1, CW2, and CW3 has been completed. If the measurement of the reverse RF signal RFr and the forward RF signal RFf of all tuner measurement control words CW1, CW2, and CW3 has been completed, the process proceeds to step S130. That is, whether the measurement of the reverse RF signal and the forward RF signal of all tuner measurement control words has been completed. If the measurement of the reverse RF signal RFr and the forward RF signal RFf of all tuner measurement control words CW1, CW2, and CW3 has not been completed, the process proceeds to step S111.

[0096] As shown in Figure 7, changes to the tuner measurement control words CW1, CW2, and CW3 are performed during the transmit gaps between the uplink (UL) signal windows. As shown in Figure 7, there are Tx time slots or gaps between the UL windows.

[0097] Before proceeding to step S130, step S120 is executed. In step S120, the feedback path unit 160 acquires the tuner scattering parameters. , , , , , , , , , , , That is, to obtain the scattering parameters of the tuner.

[0098] Next, in step S130, the feedback path unit 160, based on the reflection coefficients of at least three couplers... , , and tuner scattering parameters , , , , , , , , , , , To calibrate front-end scattering parameters , , , That is, calibrating the front-end scattering parameters.

[0099] After step S130 is executed, the process continues to steps S140 to S150 for subsequent applications.

[0100] In step S140, as shown in Figure 7, the feedback path unit 160 measures the antenna reflection coefficient Γ_Ant. For example, the antenna reflection coefficient Γ_Ant can be derived from formula (10).

[0101] Next, in step S150, as shown in Figure 7, the tuner 120 sets the optimal tuner measurement control word based on the antenna reflection coefficient Γ_Ant. That is, the optimal tuner measurement control word is set according to the antenna reflection coefficient.

[0102] Please refer to Figures 8 and 9. Figure 8 shows a flowchart of the front-end scattering parameter calibration method. According to another embodiment of the present invention, the parameters... , , , The calibration method is shown in Figure 9. Figure 9 illustrates the steps in Figure 8. Figure 8 shows the steps used to calibrate the front-end scattering parameters. , , , The method includes steps S110', S120 to S150. Step S110' includes steps S111' and S112 to S116. In the embodiment of FIG8, a multi-instruction control signal S2 (e.g., a Mobile Industrial Processor Interface (MIPI) signal) is sent to trigger an auto-tuner measurement control word switching. The tuner settings are switched multiple times via the multi-instruction control signal S2 to achieve an acceptable low software control resolution. Figure 9 As shown, a single-frame transmission subframe or uplink window is displayed, with symbols 1 to 14.

[0103] Please refer to Figures 8 through 10. Figure 10 illustrates the hardware features for performing automatic tuner measurement control word switching according to an embodiment of the present invention. As shown in Figure 10, the state machine module 121 of the tuner 120 may include a register 1211, a delay timer 1212, a counter 1213, a state machine 1214, a multiplexer 1215, and a register 1216.

[0104] In step S110', as shown in Figures 9 and 10, the feedback path unit 160 measures at least three coupler reflection coefficients Γ_MRx^1, Γ_MRx^2, and Γ_MRx^3. These at least three coupler reflection coefficients Γ_MRx^1, Γ_MRx^2, and Γ_MRx^3 are measured under different tuner measurement control words CW1, CW2, and CW3, respectively.

[0105] Step S110' includes steps S111' and S112 to S116. As shown in Figures 9 and 10, in step S111', the software control module 151 of the transmitting modem 150 sends a multi-command control signal S2 to the tuner 120.

[0106] Next, as shown in Figures 9 and 10, in step S112, the state machine module 121 of the tuner 120 writes the tuner measurement control words CW1, CW2 and CW3 into the register.

[0107] Then, as shown in Figures 9 and 10, in step S113, tuner 120 switches to the tuner measurement control word CW1 (or CW2, CW3) to be set, and waits for steps S114 and S115 to complete.

[0108] Meanwhile, in step S114, as shown in Figures 9 and 10, the transmitting modem 150 stops transmitting signals and waits for the tuner to stabilize for a period of time, such as A microseconds (any positive microsecond number).

[0109] Then, in step S115, as shown in Figures 9 and 10, the feedback path unit 160 measures the reverse radio frequency signal RFr and the forward radio frequency signal RFf, with a measurement period of B microseconds (any positive microsecond number).

[0110] Then, in step S116, as shown in Figures 9 and 10, the feedback path unit 160 determines whether the measurement of the reverse RF signal RFr and the forward RF signal RFf of all tuner measurement control words CW1, CW2, and CW3 has been completed. If the measurement of the reverse RF signal RFr and the forward RF signal RFf of all tuner measurement control words CW1, CW2, and CW3 has been completed, the process proceeds to step S130; if the measurement of the reverse RF signal RFr and the forward RF signal RFf of all tuner measurement control words CW1, CW2, and CW3 has not been completed, the process proceeds to steps S113 and S114.

[0111] As shown in Figure 9, changes to the tuner measurement control words CW1, CW2, and CW3 are performed on certain symbols within a single receive subframe or uplink window. A symbol is defined as the basic unit of data transmitted within a specific time interval, typically represented by the phase or amplitude of the modulated signal.

[0112] Before proceeding to step S130, step S120 is executed. In step S120, the feedback path unit 160 acquires the tuner scattering parameters. , , , , , , , , , , , .

[0113] Next, in step S130, the feedback path unit 160, based on the reflection coefficients of at least three couplers... , , and tuner scattering parameters , , , , , , , , , , , Calibrate front-end scattering parameters , , , .

[0114] After step S130 is executed, the process continues to steps S140 to S150 for subsequent applications.

[0115] In step S140, as shown in Figure 7, the feedback path unit 160 measures the antenna reflection coefficient Γ_Ant. For example, the antenna reflection coefficient Γ_Ant can be derived from formula (10).

[0116] Next, in step S150, as shown in Figure 7, tuner 120 sets the optimal tuner measurement control word based on the antenna reflection coefficient Γ_Ant.

[0117] Based on the above steps, performing automatic tuner measurement control word switching yields several advantages. For example, automatic tuner measurement control word switching provides an implementation example of the method proposed in this paper. The method proposed in this paper is enhanced by allowing calibration to be performed in a programmable manner and reducing control overhead. This is achieved by pre-programming the calibration sequence and triggering the calibration function.

[0118] This calibration requires sophisticated software calculations and can be performed in advance, with parameters set during periods of low flow control. Calibration can be initiated simply by triggering a low flow rate.

[0119] Please refer to Figure 11, which illustrates clock calibration for the measurement control word switching of an automatic tuner according to an embodiment of the present invention. To perform clock calibration, an internal digital controller 1217, a positive charge pump 1218, and a negative charge pump 1219 can be used. The internal digital controller 1217 includes a controller 12171 and a frequency calibration counter 12172. Clock calibration can improve timing control accuracy, which is particularly important for self-timing systems with high process variability. Figure 11 provides an example of a clock calibration implementation using an internal clock source. For example, the tuner 120 inherently integrates an oscillator in its design. The presence of the oscillator is essential for the operation of the charge pumps (positive charge pump 1218 or negative charge pump 1219). Therefore, no additional circuitry is required. This approach effectively reuses much of the existing architecture.

[0120] Furthermore, the extended write functionality supported by MIPI RFFE provides a continuous serial clock when continuously writing to virtual registers.

[0121] According to the above embodiments, the front-end scattering parameters , , , The calibration utilizes a forward RF signal RFf and a reverse RF signal RFr. A novel calibration algorithm and procedure enables accurate calibration of the front-end's scattering parameters in environments with arbitrary unknown antenna reflectivity without requiring the transmitter to be set to high isolation. The method utilizes tuner 120 for calibration, eliminating the need for additional calibration kits, and sets tuner 120 to low isolation mode. This allows signal transmission during calibration, enabling simultaneous front-end calibration and normal operation of the mobile device. This calibration process enables real-time measurement of front-end scattering parameters in network-allocated frequency scenarios. , , , This reduces the impact of factors such as component differences and temperature variations. The method involves switching at least three tuner states without affecting signal transmission, thus ensuring accurate S (scattering) parameter calibration without using the antenna reflection coefficient Γ_Ant.

[0122] In this embodiment of the invention, the receiver may include a storage medium containing computer (calculator) code executable by a computer (calculator) to implement the steps of the method described above, for example... Figure 6 and Figure 8 The methods and steps.

[0123] While the invention has been described by way of example and according to preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments. Rather, it is intended to cover various modifications and similar arrangements (as will be apparent to those skilled in the art). Therefore, the scope of the appended claims should be given the broadest interpretation to cover all such modifications and similar arrangements.

Claims

1. A method for calibrating front-end scattering parameters, characterized in that, include: Measure the reflection coefficients of at least three couplers under at least three different tuner measurement control words; Acquire multiple tuner scattering parameters corresponding to the at least three different tuner measurement control words; as well as The front-end scattering parameters are calibrated based on the reflection coefficients of at least three couplers and the scattering parameters of the tuner.

2. The method as described in claim 1, characterized in that, The reflection coefficients of at least three couplers are measured in offline, real-time, or hybrid modes.

3. The method as described in claim 2, characterized in that, The switching between the tuner measurement control words is controlled by multiple single-instruction control signals or by multiple-instruction control signals.

4. The method as described in claim 3, characterized in that, Both the single instruction control signal and the multiple instruction control signal are Mobile Industrial Processor Interface (MIPI) signals.

5. The method as described in claim 1, characterized in that, The reflection coefficients of the at least three couplers are measured via a feedback path, and the RF signal transmission paths in the RF front-end circuit (RFFE) and the transmit (Tx) modem remain fixed while the reflection coefficients of the at least three couplers are measured.

6. The method as described in claim 1, characterized in that, When the reflection coefficients of the at least three couplers are measured in real time, the measurement time of the reflection coefficients of the at least three couplers is within 0.1 seconds.

7. The method as described in claim 1, characterized in that, The reflection coefficients of at least three couplers were measured with the antenna reflection coefficients constant.

8. The method as described in claim 1, characterized in that, When the input port of the RF front-end circuit (RFFE) is connected to the coupler and the output port of the RF front-end circuit is connected to the tuner, measure the reflection coefficient of each of the at least three couplers.

9. The method according to claim 1, characterized in that, Also includes: The antenna reflection coefficient is calibrated based on the calibrated front-end scattering parameters.

10. The method as described in claim 1, characterized in that, In the step of calibrating the front-end scattering parameters, the front-end scattering parameters are calibrated in the following way: ; , and The reflection coefficients of the three couplers were measured under three different tuner measurement control words; ; ; ; It is the reflection coefficient of the RFFE input port, which represents the proportion of signal waves entering the RFFE input port that are reflected back to the RFFE input port; It is the transmission coefficient from the RFFE input port to the RFFE output port, representing the proportion of the signal wave entering the RFFE input port that is transmitted to the RFFE output port; It is the transmission coefficient from the RFFE output port to the RFFE input port, representing the proportion of the signal wave entering the RFFE output port that is transmitted to the RFFE input port; It is the reflection coefficient of the RFFE output port, which represents the proportion of the signal wave entering the RFFE output port that is reflected back to the RFFE output port; , , , , , , , , , , and These are the tuner scattering parameters corresponding to different tuner measurement control words.

11. A user equipment, characterized in that, include: antenna; A tuner, connected to the antenna, wherein the tuner is used to switch at least three different tuner measurement control words; The radio frequency front-end circuit (RFFE) is connected to the tuner; Coupler, connected to the RF front-end circuit; Transmit (Tx) modem, connected to the coupler; and A feedback path unit is connected to the RF front-end circuit, wherein the feedback path unit is used to perform the steps of the method as described in any one of claims 1 to 10.

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