A power automatic calibration method for frequency hopping scattering communication

Abstract

The application relates to the technical field of frequency hopping scattering communication, and provides a power automatic calibration method for frequency hopping scattering communication, which is suitable for a scattering communication equipment, and the scattering communication equipment comprises a baseband processing unit, a main control unit and a power amplifier unit. The main process of the power automatic calibration method is as follows: the main control unit inquires the forward voltage value corresponding to the rated power of the current temperature and frequency table from the power amplifier unit, calculates the target forward voltage value of the current setting power of each frequency point, and delivers the target forward voltage value to the baseband processing unit; the baseband processing unit detects the real-time forward voltage value of each frequency point, compares the real-time forward voltage value with the target voltage value, adjusts the digital attenuation amount of the baseband processing unit, changes the input signal power of the power amplifier unit, and realizes power automatic calibration. The power automatic calibration method has the advantages of good real-time performance, high accuracy, and adaptability to the temperature and frequency changes of the power amplifier unit without human intervention.

Description

Technical Field

[0001] This invention relates to the field of frequency hopping scattering communication technology, and provides an automatic power calibration method for frequency hopping scattering communication. Background Technology

[0002] Tropospheric scattering communication is a typical beyond-line-of-sight communication method. Due to the long propagation distance and high link loss, it requires very high power amplifier power. Furthermore, with the development of frequency hopping scattering communication in recent years, the signal bandwidth has been significantly improved, which places higher demands on the power flatness of the power amplifier throughout the entire communication frequency band.

[0003] Since different power amplifiers have different transmit power at the factory, it is difficult to guarantee that the transmit power of each device is within the specified range. Furthermore, for broadband frequency hopping scatter communication systems, the actual transmit power at each frequency point also varies. Traditional power calibration methods require manual calibration of each power amplifier after it leaves the factory by measuring it with a power meter. When there are a large number of devices, the workload is enormous and the efficiency is extremely low.

[0004] Therefore, there is an urgent need to invent an automatic power calibration method for frequency hopping scattering communication that can automatically adjust the power of each frequency point during equipment operation without human intervention, simplifying the manual calibration steps, reducing unnecessary time waste, and improving work efficiency. Summary of the Invention

[0005] In view of this, the present invention provides an automatic power calibration method for frequency hopping scattering communication, which uses a baseband processing unit to detect the positive voltage value fed back by the power amplifier unit and the target voltage value in real time, and adjusts the power of the input excitation signal of the power amplifier unit to achieve automatic power calibration.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An automatic power calibration method for frequency-hopping scatter communication is provided, applicable to scatter communication equipment, which includes a baseband processing unit, a main control unit, and a power amplifier unit. The method specifically includes the following steps:

[0008] Step S1: The main control unit queries the power amplifier unit for the forward voltage value V0 corresponding to the current rated power Pr based on the current temperature and frequency, and calculates the forward voltage value V1 corresponding to the current set transmit power Ps at each frequency point, and sends V1 as the target forward voltage to the baseband processing unit.

[0009] Step S2: The baseband processing unit detects the instantaneous positive voltage value fed back by the power amplifier unit, and calculates the real-time positive voltage value V2 for each frequency point according to the frequency hopping point and frequency hopping time.

[0010] Step S3: The baseband processing unit calculates the difference ΔV between the real-time forward voltage value V2 at each frequency point and the target forward voltage value V1 sent by the main control unit, and compares it with the preset threshold ΔV. th In comparison, if -ΔV th <ΔV<ΔV th If the current transmit power is within a reasonable range, no power adjustment is required; otherwise, calculate the digital attenuation adjustment ΔF for each frequency point based on ΔV, and update the digital attenuation F(n).

[0011] Step S4: At the beginning of each hop, the baseband processing unit reads the pre-stored lookup table according to the frequency point number and the corresponding digital attenuation F(n) to obtain the baseband signal scaling factor Z, and multiplies it with the baseband signal to realize the adjustment of the baseband signal output power.

[0012] Step S5: The main control unit determines whether the temperature and frequency meters have changed. If the temperature or frequency meters have changed, steps S1 to S4 are repeated; otherwise, steps S2 to S4 are repeated.

[0013] Furthermore, the power amplifier unit pre-stores the forward voltage values ​​corresponding to the rated power at different temperatures and frequencies.

[0014] Furthermore, the formula for calculating the forward voltage value V1 in step S1 is: V1=V0–X·(Pr-Ps), where V0 is the forward voltage value corresponding to the rated power, Pr is the rated power value, Ps is the set transmission power value, and X is the power-voltage ratio coefficient.

[0015] Furthermore, in step S2, the baseband processing unit takes the voltage sample value at the midpoint of each hop and performs a statistical average to obtain the real-time positive voltage value V2.

[0016] Furthermore, the preset threshold calculation formula in step S3 is: ΔV th =ΔP·X, where ΔP is the maximum allowable power error and X is the power-to-voltage ratio coefficient.

[0017] Furthermore, the formula for calculating the digital attenuation adjustment ΔF in step S3 is as follows:

[0018]

[0019] Where ΔV is the difference between the real-time forward voltage value V2 and the target forward voltage value V1, X is the power-to-voltage ratio coefficient, and ΔF max This is the upper limit for the digital attenuation adjustment.

[0020] Furthermore, the update formula for the digital attenuation amount F(n) in step S3 is: F(n) = F(n-1) + ΔF, where F(n) is the digital attenuation amount at the next moment, F(n-1) is the digital attenuation amount at the current moment, the initial value is set to 0, and ΔF is the digital attenuation adjustment amount.

[0021] Furthermore, the power-to-voltage ratio coefficient X is a power amplifier unit parameter, representing the change in positive voltage value for every 1dB change in transmit power.

[0022] Furthermore, the lookup table in step S4 pre-stores scaling factors corresponding to different digital attenuation amounts, with the digital attenuation amount having an accuracy of 0.1dB and the scaling factor quantized as a 16-bit signed number.

[0023] A communication device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described above.

[0024] The advantages of this invention compared to the prior art are:

[0025] This invention adjusts the digital attenuation based on the difference between the real-time forward voltage value fed back by the power amplifier unit and the target forward voltage value, thereby adjusting the input signal power of the power amplifier. It achieves automatic power calibration without human intervention, with good real-time performance and high accuracy. It can also adapt to changes in the temperature and frequency of the power amplifier unit, eliminating the drawbacks of manual calibration required in existing power calibration methods, saving power calibration time, and improving work efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the application of an automatic power calibration method provided in an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of an automatic power calibration method provided in an embodiment of the present invention. Detailed Implementation

[0028] In the following description, specific details such as particular device structures and techniques are set forth for illustrative purposes and not for limitation, so as to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0030] like Figure 1 As shown, this automatic power calibration method is applied to frequency hopping scattering communication equipment. The frequency hopping scattering communication equipment includes a baseband processing unit, a main control unit, and a power amplifier unit. In the real-time example of the automatic power calibration method of this invention, the main function of the baseband processing unit is to detect the real-time positive voltage value fed back by the power amplifier, adjust the digital attenuation, change the output signal power, and control the frequency hopping frequency and time. The main function of the power amplifier unit is to provide the positive voltage value corresponding to the rated power and to give the positive voltage value of the actual transmission power in real time. The main function of the main control unit is to query the positive voltage value corresponding to the rated power of the power amplifier unit, calculate the target positive voltage value according to the actual set power, and send it to the baseband processing unit.

[0031] In this embodiment of the invention, the power amplifier unit has the following characteristic: the forward voltage value and the transmission power value have a linear relationship.

[0032] The following is combined with Figure 2 The automatic power calibration method provided in this embodiment of the invention will be described in detail. The automatic power calibration includes the following steps:

[0033] In step S201, the main control unit queries the power amplifier unit for the forward voltage value V0 corresponding to the current rated power Pr based on the current temperature and frequency, and calculates the forward voltage value V1 corresponding to the current set transmit power Ps at each frequency point. V1 is then sent to the baseband processing unit as the target forward voltage.

[0034] The formula for calculating the target forward voltage value is: V1=V0-X·(Pr-Ps), where X is the power-to-voltage ratio coefficient, with the unit being mV / dB, which represents the change in forward voltage value for every 1dB change in transmit power.

[0035] In this embodiment of the invention, according to the characteristics of the power amplifier unit, the power gain corresponding to different temperatures and frequencies is different. Therefore, the power amplifier unit stores the positive voltage values ​​corresponding to the rated power at different temperatures and frequencies. The main control unit needs to query the corresponding positive voltage value from the power amplifier unit according to the current temperature and frequency table. The positive voltage value is actually a set of values, which corresponds one-to-one with the frequency hopping point used. For example, 8-frequency hopping corresponds to 8 positive voltage values.

[0036] In this embodiment of the invention, after the main control unit retrieves the forward voltage value corresponding to the rated power, it needs to calculate the forward voltage value of the currently set power. This value serves as the target forward voltage value and is a reference for power adjustment, corresponding one-to-one with the frequency hopping points. The calculation of the target forward voltage value requires the voltage-to-power ratio coefficient X, which is determined by the characteristics of the power amplifier itself. In this embodiment, this coefficient is 20mV / dB, indicating that a 1dB change in power corresponds to a 20mV change in forward voltage. For example, if the rated power of the power amplifier is 50dBm, and at 50°C, the rated power of frequency point f0 corresponds to a forward voltage value of 1600mV, and the actual set transmit power is 45dBm, then the target voltage value of f0 is 1600 - 20 × (50 - 45) = 1500mV.

[0037] After the main control unit calculates the target positive voltage value, it sends it to the baseband processing unit.

[0038] In step S202, the baseband processing unit detects the instantaneous positive voltage value fed back by the power amplifier unit, and calculates the real-time positive voltage value V2 for each frequency point according to the frequency hopping point and frequency hopping time.

[0039] In this embodiment of the invention, the power amplifier unit feeds back the real-time positive voltage value to the baseband processing unit through a differential interface. This positive voltage value has high real-time performance and can indicate the real-time power of the power amplifier unit. The baseband processing unit completes instantaneous voltage acquisition through the XADC module of the FPGA chip. The baseband processing unit is also responsible for frequency hopping point and frequency hopping time control, and can distinguish the specific frequency point corresponding to the acquired voltage value. Since frequency hopping switching requires a short settling time, in order to ensure the validity of the acquired voltage, the voltage sample value at the midpoint of each hop is taken. The number of sampling points per hop can be set to 32. The average value of the 32 voltages is taken as the positive voltage value of the current hop. Then, the voltage values ​​of each frequency point within 1 second are counted as the final real-time positive voltage value.

[0040] Step S203: The baseband processing unit calculates the difference ΔV between the real-time forward voltage value V2 at each frequency point and the target forward voltage value V1 sent by the main control unit, and compares it with a preset threshold ΔV. th In comparison, if -ΔV th <ΔV<ΔV th If the current transmit power is within a reasonable range, no power adjustment is required; otherwise, the digital attenuation adjustment ΔF for each frequency point needs to be calculated based on ΔV, and the digital attenuation F(n) needs to be updated.

[0041] The preset threshold calculation formula is: ΔV th = ΔP·X, where ΔP is the maximum allowable power error. In this embodiment of the invention, ΔP is set to 0.5dB, and X = 20mV / dB, then ΔV th =10mv.

[0042] The magnitude and direction of power adjustment need to be determined based on the difference ΔV between the real-time forward voltage value V2 and the target forward voltage value V1: ΔV > 0 indicates that the actual transmission power is greater than the preset power, requiring an increase in digital attenuation and a decrease in transmission power; ΔV < 0 indicates that the actual transmission power is less than the preset power, requiring a decrease in digital attenuation and an increase in transmission power. The formula for calculating the digital attenuation adjustment ΔF is as follows:

[0043]

[0044] Where ΔV is the difference between the real-time forward voltage value V2 and the target forward voltage value V1, X is the power-to-voltage ratio coefficient, and ΔF max This is the upper limit of the digital attenuation adjustment, the purpose of which is to avoid affecting communication quality by adjusting too much at once. In the embodiments of this invention, ΔF max Set to 1dB.

[0045] The update formula for the digital decay F(n) is: F(n) = F(n-1) + ΔF, where F(n) is the digital decay at the next time step, F(n-1) is the digital decay at the current time step, and the initial value is set to 0.

[0046] For example: If the target forward voltage V1 at a certain frequency is 1500mV and the real-time forward voltage V2 is 1550mV, then ΔV = 50mV > ΔV th =10mV, the digital attenuation needs to be increased. The digital attenuation adjustment ΔF = ΔV / X = 50 / 20 = 2.5dB, which is greater than the preset upper limit (1dB). Therefore, the actual digital attenuation adjustment should be 1dB. If the current digital attenuation F(n-1) = 5dB, then the updated digital attenuation should be F(n) = 5 + 1 = 6dB. Conversely, if the target forward voltage V1 at a certain frequency is 1500mV and the real-time forward voltage V2 is 1490mV, then ΔV = -10mV ≤ -ΔV th = -10mV, the digital attenuation needs to be reduced. The digital attenuation adjustment ΔF = ΔV / X = -10 / 20 = -0.5dB, which is less than the preset upper limit (1dB). Therefore, if the current digital attenuation F(n-1) = 3dB, the updated digital attenuation is F(n) = 3 - 0.5 = 2.5dB.

[0047] In step S204, at the beginning of each hop, the processing unit reads the pre-stored lookup table according to the frequency point number and the corresponding digital attenuation F(n) to obtain the baseband signal scaling factor Z, and multiplies it with the baseband signal to realize the adjustment of the baseband signal output power.

[0048] In this embodiment of the invention, the scaling factor is quantized as 16-bit data and pre-stored in ROM. The digital attenuation accuracy is 0.1dB. Using the digital attenuation F(n) as the read address, the corresponding scaling factor can be read. For example, a digital attenuation of 0dB corresponds to a scaling factor of 32767 at ROM address 0; a digital attenuation of 1dB corresponds to a scaling factor of 29203 at ROM address 10, and so on. To ensure that the scaling factor applies correctly to the corresponding frequency point, the ROM read address value needs to be updated at the start of frequency hopping. The scaling factor is multiplied by the baseband signal, directly affecting the amplitude of the digital signal, and further affecting the output signal power of the baseband processing unit.

[0049] In step S205, the main control unit determines whether the temperature and frequency meters have changed. If the temperature or frequency meters have changed, steps S201 to S204 are repeated; otherwise, steps S202 to S204 are repeated.

[0050] In this embodiment of the invention, since the power gain of the power amplifier unit varies at different temperatures and frequencies, the forward voltage value corresponding to the rated power of the power amplifier also varies. Therefore, when the temperature or frequency changes, the main control unit needs to re-query the forward voltage value corresponding to the rated power and recalculate and issue the target forward voltage value. Steps S203 and S204 need to be executed periodically. Setting the period too short may cause power oscillation. In this embodiment of the invention, the period is set to 3 seconds.

[0051] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An automatic power calibration method for frequency hopping scattering communication, characterized in that, This applies to scatter communication equipment, which includes a baseband processing unit, a main control unit, and a power amplifier unit, and specifically includes the following steps: Step S1: The main control unit queries the power amplifier unit for the forward voltage value V0 corresponding to the current rated power Pr based on the current temperature and frequency, and calculates the forward voltage value V1 corresponding to the current set transmit power Ps at each frequency point, and sends V1 as the target forward voltage to the baseband processing unit. Step S2: The baseband processing unit detects the instantaneous forward voltage value fed back by the power amplifier unit, and calculates the real-time forward voltage value V2 for each frequency point based on the frequency hopping point and frequency hopping time; Step S3: The baseband processing unit calculates the difference ΔV between the real-time forward voltage value V2 at each frequency point and the target forward voltage value V1 sent by the main control unit, and compares it with the preset threshold ΔV. th In comparison, if -ΔV th <ΔV<ΔV th If the current transmit power is within a reasonable range, no power adjustment is required; otherwise, calculate the digital attenuation adjustment ΔF for each frequency point based on ΔV, and update the digital attenuation F(n). Step S4: At the beginning of each hop, the baseband processing unit reads the pre-stored lookup table according to the frequency point number and the corresponding digital attenuation F(n) to obtain the baseband signal scaling factor Z, and multiplies it with the baseband signal to realize the adjustment of the baseband signal output power. Step S5: The main control unit determines whether the temperature and frequency meters have changed. If the temperature or frequency meters have changed, steps S1 to S4 are repeated; otherwise, steps S2 to S4 are repeated. The formula for calculating the digital attenuation adjustment ΔF in step S3 is as follows: ； Where ΔV is the difference between the real-time forward voltage value V2 and the target forward voltage value V1, X is the power-to-voltage ratio coefficient, and ΔF max This is the upper limit for the digital attenuation adjustment. In step S3, the update formula for the digital attenuation amount F(n) is: F(n) = F(n-1) + ΔF, where F(n) is the digital attenuation amount at the next moment, F(n-1) is the digital attenuation amount at the current moment, the initial value is set to 0, and ΔF is the digital attenuation adjustment amount.

2. The automatic power calibration method for frequency hopping scattering communication according to claim 1, characterized in that, The power amplifier unit has pre-stored the forward voltage values ​​corresponding to the rated power at different temperatures and frequencies.

3. The automatic power calibration method for frequency hopping scattering communication according to claim 1, characterized in that, The formula for calculating the forward voltage value V1 in step S1 is: V1 = V0 – X ∙ (Pr - Ps), where V0 is the forward voltage value corresponding to the rated power, Pr is the rated power value, Ps is the set transmission power value, and X is the power-voltage ratio coefficient.

4. The automatic power calibration method for frequency hopping scattering communication according to claim 1, characterized in that, In step S2, the baseband processing unit takes the voltage sample value at the midpoint of each hop and performs a statistical average to obtain the real-time positive voltage value V2.

5. The automatic power calibration method for frequency hopping scattering communication according to claim 1, characterized in that, The preset threshold calculation formula in step S3 is: ΔV th = ΔP ∙ X, where ΔP is the maximum allowable power error and X is the power-to-voltage ratio coefficient.

6. The automatic power calibration method for frequency hopping scattering communication according to claim 3 or 5, characterized in that, The power-to-voltage ratio coefficient X is a parameter of the power amplifier unit, representing the change in positive voltage value for every 1dB change in transmit power.

7. The automatic power calibration method for frequency hopping scattering communication according to claim 1, characterized in that, The lookup table in step S4 pre-stores scaling factors corresponding to different digital attenuation levels. The digital attenuation level has an accuracy of 0.1 dB, and the scaling factor is quantized as a 16-bit signed number.

8. A communication device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 7 above.

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