Method and system for automatically eliminating self-excitation of coverage system of micro-distributed repeater

Abstract

The invention provides a method and a system for automatically eliminating self-excitation of a coverage system of a micro-distributed repeater to solve the self-excitation problem of the system during engineering deployment, and the method comprises the following steps: under a predetermined self-excitation detection triggering condition, a main control unit performs self-excitation detection; the main control unit sends an instruction to a target coverage unit in the plurality of coverage units, and controls the target coverage unit to emit a preset test signal; the main control unit receives a test signal propagated through the space path; the main control unit calculates the space path loss between the target coverage unit and the main control unit according to the received test signal strength; the main control unit compares the calculated space path loss with a system gain threshold value, and judges whether the target coverage unit is a self-excitation source coverage unit causing system self-excitation or not; and if the target coverage unit is judged as the self-excitation source coverage unit, sending a gain adjustment instruction to the target coverage unit, and reducing the gain of the target coverage unit to eliminate self-excitation.

Description

Technical Field

[0001] This invention relates to the field of mobile communication signal coverage technology, specifically to a method for automatically eliminating self-excitation in a micro-distributed repeater coverage system and the micro-distributed repeater coverage system. Background Technology

[0002] Micro-distributed repeater coverage systems are an effective solution for addressing weak signal coverage areas both indoors and outdoors. They typically consist of a three-tiered architecture: a main control unit, an extension unit, and multiple coverage units. The main control unit couples the base station signal, which is then distributed to multiple coverage units via the extension units for amplified coverage. During deployment, if the isolation between the transmitting antenna of a coverage unit and the receiving antenna of the main control unit is insufficient (i.e., the spatial path loss is less than the total system gain), a closed positive feedback loop will form, leading to system self-oscillation.

[0003] Self-oscillation can have serious consequences: self-oscillation signals can cause excessive input signals to the main control unit, which may lead to amplifier saturation or even damage; even if the amplifier is not damaged, it will operate in the nonlinear region, which will cause the system gain to decrease and the performance indicators such as error vector amplitude to deteriorate, seriously affecting the communication quality.

[0004] Current solutions mostly rely on self-oscillation detection within a single device, which cannot address system-level self-oscillation issues across devices in micro-distributed systems. In engineering practice, self-oscillation is often avoided by manually and roughly lowering the gain of the entire system, but this sacrifices the signal strength of distant coverage units, failing to achieve optimal coverage. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method and system for automatically eliminating self-oscillation in a micro-distributed repeater coverage system, thereby solving the self-oscillation problem during engineering deployment and improving the signal quality of the coverage area of ​​the micro-distributed repeater coverage system.

[0006] The technical solution is as follows: A method for automatically eliminating self-excitation in a micro-distributed repeater coverage system, based on a distributed repeater coverage system including a main control unit, an extension unit, and a coverage unit, characterized in that the method includes the following steps: Step 1: Under the predetermined self-excitation detection trigger conditions, the main control unit performs self-excitation detection; Step 2: The main control unit sends a command to one of the target coverage units among the multiple coverage units, controlling the target coverage unit to transmit a preset test signal; Step 3: The main control unit receives the test signal propagated through the spatial path; Step 4: The main control unit calculates the spatial path loss between the target coverage unit and the main control unit based on the received test signal strength; Step 5: The main control unit compares the calculated spatial path loss with the system gain threshold to determine whether the target coverage unit is a self-excitation source coverage unit that causes system self-excitation; Step 6: If the target coverage unit is determined to be a self-oscillating source coverage unit, the main control unit sends a gain adjustment command to the target coverage unit to reduce the gain of the target coverage unit to eliminate self-oscillation.

[0007] Furthermore, the predetermined self-oscillation detection triggering conditions include: the self-oscillation detection function of the micro-distributed repeater coverage system being activated or the micro-distributed repeater coverage system restarting from a power-off state.

[0008] Furthermore, the main control unit selects a coverage unit that has not yet been detected as a new target coverage unit according to a preset order, and repeats steps 2 to 5 until all coverage units are traversed or all coverage units are located.

[0009] Furthermore, the feature is that, in step 5, the system gain threshold is determined based on the real-time gain of the system, and the main control unit calculates the real-time gain of the system using the following formula: System real-time gain = main control unit gain + coverage unit gain - (main control unit output power - coverage unit received power); When the spatial path loss is less than the system real-time gain, the target coverage unit is identified as a self-excited source coverage unit.

[0010] Furthermore, step 6 specifically includes the following steps: Based on the frequency of the test signal and the calculated spatial path loss, the spatial distance between the target coverage unit and the main control unit is inferred. Based on the calculated spatial distance and the frequency of the system's operating frequency band, the actual spatial path loss under each operating frequency band is calculated. Based on the actual spatial path loss and real-time system gain in each operating frequency band, the target gain attenuation value that needs to be set for the self-excited source coverage unit is calculated, and the gain adjustment command is generated.

[0011] Furthermore, in step 6, the target gain attenuation value is calculated using the following formula: Target gain attenuation value = System real-time gain - Spatial path loss.

[0012] Furthermore, when the spatial path loss is less than the system real-time gain minus a preset margin value, the target coverage unit is determined to be a self-excited source coverage unit.

[0013] Furthermore, in step 6, the method for reducing the gain of the target coverage cell also includes: Set the target coverage cell gain to the preset minimum gain value; The gain of the target coverage unit is gradually increased using a preset step value. After each rebound, a new self-excitation judgment is performed; Until a self-excited loop is detected, the gain of the target coverage unit is backed down by one step value.

[0014] A micro-distributed repeater coverage system for automatically eliminating self-oscillation includes: The main control unit is used for wireless or wired coupling of base station signals; An expansion unit is provided, at least one of which is connected to the main control unit; A coverage unit, connected to the expansion unit, is used to amplify and cover the signal; The main control unit is configured to execute the method described above.

[0015] Furthermore, the main control unit, the expansion unit, and the coverage unit each include a CPU unit and an FSK communication module; the preset test signal adopts an FSK waveform transmitted through the FSK communication module of the target coverage unit.

[0016] Furthermore, the main control unit also includes at least one of a Bluetooth communication module, a WiFi communication module, and an LTE communication module.

[0017] The method for automatically eliminating self-oscillation in a micro-distributed repeater coverage system of the present invention, through the linkage between the main control unit and each coverage unit, can systematically check and accurately locate the specific coverage unit causing the system self-oscillation, and perform targeted gain adjustments, avoiding the problem of reducing the total gain of the main control unit and affecting the overall system performance in traditional solutions; the entire detection and elimination process is completed automatically by the system without manual intervention, which can significantly reduce the difficulty and cost of deployment and subsequent maintenance; by automatically eliminating self-oscillation, the amplifier is ensured to operate in the linear region, which can effectively improve the signal strength and signal quality of the coverage area and protect the hardware equipment from damage. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the steps of a method for automatically eliminating self-excitation in a micro-distributed repeater coverage system, as described in this embodiment. Figure 2 This is a schematic diagram of the repeater coverage system in the embodiment; Figure 3 This is a schematic diagram of the main control unit of the repeater coverage system in the embodiment; Figure 4 This is a schematic diagram of the expansion unit of the repeater coverage system in the embodiment; Figure 5 This is a schematic diagram of the coverage unit of the repeater coverage system in the embodiment. Detailed Implementation

[0019] See Figure 1 The micro-distributed repeater coverage system provided by this invention includes a main control unit 100, an expansion unit 200, and multiple coverage units 300. In this embodiment, a one-to-four configuration is used as an example, meaning one main control unit 100 is connected to one expansion unit 200, and one expansion unit 200 is connected to four coverage units 300. It should be understood that the expansion unit 200 can also connect to eight coverage units, and multiple expansion units 200 can be configured; the system of this invention is equally applicable.

[0020] The main control unit 100 couples the base station signal through its receiving antenna or through a wired interface. The main control unit 100 is connected to the expansion unit 200 through an RF cable. The expansion unit 200 distributes the power of the received signal and connects it to four coverage units 300 through RF cables. Each coverage unit 300 transmits the amplified signal through a coverage antenna to achieve signal coverage of the target area.

[0021] In certain deployment scenarios, the signal transmitted by the coverage antenna of the coverage unit 300 may be received by the receiving antenna of the main control unit 100, forming a closed signal loop. When the spatial path loss of this loop is less than the total system gain, self-oscillation occurs.

[0022] See Figure 2 To achieve automatic elimination of self-oscillation, this invention provides a method for automatically eliminating self-oscillation in a micro-distributed repeater coverage system, comprising the following steps: Step 1: Under the predetermined self-excitation detection trigger conditions, the main control unit performs self-excitation detection; Step 2: The main control unit sends a command to one of the target coverage units among the multiple coverage units, controlling the target coverage unit to transmit a preset test signal; Step 3: The main control unit receives the test signal propagated through the spatial path; Step 4: The main control unit calculates the spatial path loss between the target coverage unit and the main control unit based on the received test signal strength; Step 5: The main control unit compares the calculated spatial path loss with the system gain threshold to determine whether the target coverage unit is a self-excitation source coverage unit that causes system self-excitation; Step 6: If the target coverage unit is determined to be a self-oscillating source coverage unit, the main control unit sends a gain adjustment command to the target coverage unit to reduce the gain of the target coverage unit to eliminate self-oscillation.

[0023] In one embodiment, in step 1, the main control unit 100 is activated when any of the following predetermined trigger conditions are met: When the system's self-oscillation detection function is activated, for example, by turning the self-oscillation detection switch on through the network management system or local configuration interface, if the system is running, the main control unit will immediately start the self-oscillation detection. When the system is powered on again from a power-off state, after the main control unit 100, the expansion unit 200 and all coverage units 300 have completed initialization and are running stably, the main control unit 100 automatically starts self-oscillation detection to check whether self-oscillation exists in the current deployment environment.

[0024] In this embodiment, in step 2, the main control unit 100 sends a command to the coverage unit 300 via FSK communication, causing its FSK module to transmit a preset test signal waveform through the amplification link and the coverage antenna. For example, in this embodiment, it is an FSK signal with a frequency of 400MHz. At this time, other coverage units do not transmit test signals.

[0025] In this embodiment, in step 3, the FSK module of the main control unit 100 attempts to receive the test signal on its receiving path. In step 4, if a test signal is received, the spatial path loss between the two will be calculated based on the power of the received signal and the known test signal transmission power of the coverage unit 300. In the embodiment, in step 5, the main control unit compares the calculated spatial path loss with the system gain threshold to determine whether the target coverage unit is a self-excitation source coverage unit that causes system self-excitation. The physical condition for self-excitation is that the loop gain is greater than 1, that is, the total system gain is greater than the total loop loss. In this embodiment, the loop loss is mainly composed of spatial path loss, and the system gain threshold is determined based on the real-time gain of the system. The main control unit calculates the system's real-time gain using the following formula: System real-time gain = main control unit gain + coverage unit gain - (main control unit output power - coverage unit received power). The calculated real-time system gain is highly accurate, reflecting the true end-to-end gain under all current system parameter settings. In this embodiment, when the spatial path loss is less than the real-time system gain, the target coverage unit is identified as a self-excited source coverage unit. The identification condition is as follows: ;in, For spatial path loss, To improve the real-time gain of the system, in this embodiment, the real-time gain of the system is dynamically calculated by measuring the output power of the main control unit and the received power of the coverage unit in real time, so as to make the self-oscillation judgment more accurate and adapt to different cable losses and deployment environments.

[0026] In another embodiment, to improve robustness, a preset margin value, such as 10dB, is introduced, and the judgment condition becomes: ;in, For spatial path loss, This represents the system's real-time gain.

[0027] If the judgment result is If the target coverage unit fails to transmit the test signal, it is considered that the target coverage unit has not caused self-oscillation. The main control unit then instructs the target coverage unit to stop transmitting the test signal and continues to perform the same detection steps for the next coverage unit. In the embodiment, in step 6, if the spatial path loss is less than the system real-time gain, the system determines that the target coverage unit is a self-oscillation source coverage unit, and the main control unit immediately initiates self-oscillation cancellation: Calculate the required gain attenuation. To make the loop gain less than 1, additional attenuation needs to be introduced. The target gain attenuation value = system real-time gain - spatial path loss, expressed as: ; in, The target gain attenuation value to be applied is used to break the self-oscillation. For spatial path loss, The real-time gain of the system is given by: system real-time gain = main control unit gain + coverage unit gain - (main control unit output power - coverage unit received power).

[0028] The main control unit generates a gain adjustment command, which includes the calculated target gain attenuation value. The signal is then sent to the target coverage unit experiencing self-oscillation via an FSK signal. Upon receiving the gain adjustment command, the target coverage unit experiencing self-oscillation controls its internal adjustable attenuator to reduce the gain. dB.

[0029] In the embodiment, in step 6, the spatial distance between the target coverage unit and the main control unit is inferred based on the frequency of the test signal and the calculated spatial path loss. Based on the calculated spatial distance and the frequency of the system's operating frequency band, the actual spatial path loss under each operating frequency band is calculated. Based on the actual spatial path loss and real-time system gain in each operating frequency band, the target gain attenuation value that needs to be set for the self-excited source coverage unit is calculated, and a gain adjustment command is generated.

[0030] Based on the frequency of the test signal and the calculated spatial path loss, the spatial distance between the target coverage unit and the main control unit is inferred. Based on the calculated spatial distance and the frequency of the system's operating frequency band, the actual spatial path loss under each operating frequency band is calculated. Based on the actual spatial path loss and real-time system gain in each operating frequency band, the target gain attenuation value that needs to be set for the self-excited source coverage unit is calculated, and the gain adjustment command is generated. The target gain attenuation value is calculated by the following formula: Target gain attenuation value = Real-time system gain - Spatial path loss.

[0031] In this embodiment, in step 6, the spatial distance between the target coverage unit and the main control unit is calculated based on the frequency of the test signal and the calculated spatial path loss, using the following formula: Space path loss calculation formula: Space path loss = 32.5 + 20 * LOG (frequency band) + 20 * LOG (spatial distance); The formula for calculating spatial distance using spatial path loss and frequency band inverse calculation is as follows: Spatial distance (km) = 10^((spatial path loss - 32.5 - 20 * LOG(frequency band)) / 20); Where, ^ symbol represents power, LOG represents the logarithmic function with a base of 10; The main control unit will substitute the calculated spatial distance into the actual frequency bands in which the system operates, and calculate the actual spatial path loss corresponding to each frequency band. The main control unit sends the required attenuation values ​​for each frequency band to the target coverage unit, which then independently adjusts the gain of the amplification links for each frequency band.

[0032] Table 1 below shows examples of the calculated path loss and final ATT settings for each frequency band: Table 1 Taking the 700MHz band as an example: the measured main control output power is 17dBm, the coverage received power is -24dBm, the calculated real-time system gain is 60dB + 60dB - 41dB = 79dB, the measured spatial path loss is 55.24dB, and the calculated target gain attenuation value is: .

[0033] After the calculation is completed, the main control unit will send the corresponding The command is sent to the self-excited source coverage unit, which then adjusts its internal attenuator to reduce the gain.

[0034] In another embodiment, after determining that the target coverage unit has caused self-oscillation, the main control unit sends an instruction to the target coverage unit to immediately set the gain of all its relevant frequency bands to the minimum gain value allowed by the system. The purpose is to break the self-oscillation loop in the shortest possible time and avoid damage to the amplifier due to continuous overload. After the target coverage unit confirms that the gain has been set to the minimum value, the main control unit initiates the following process: The system presets a gain recovery step value, such as 5dB. The main control unit sends a command to the target coverage unit, instructing it to increase its gain by one step value, that is, increase it by 5dB from the minimum gain. After the target coverage unit completes the gain adjustment, the main control unit immediately repeats the self-oscillation judgment process. If no self-oscillation is detected, it continues to increase the gain by another 5dB. If a weak self-oscillation signal is detected, it indicates that the current gain has reached or slightly exceeded the stability critical point. When self-oscillation is detected again at a certain gain level, the main control unit sends a command to the target coverage unit to back its gain by one step value, that is, subtract 5dB. The gain value at this time is the maximum gain value that the target coverage unit can stably operate under the current antenna deployment and space environment. The main control unit records this value and determines the gain of the target coverage unit.

[0035] If the main control unit detects that self-oscillation still exists after reducing the gain of the target coverage unit to its minimum, the system will determine that the antenna isolation is severely insufficient, indicating improper construction. In this case, the main control unit will stop adjusting the gain of the target coverage unit and generate an antenna isolation fault alarm, reporting it to maintenance personnel through the network management system, indicating that on-site physical adjustments are required.

[0036] This invention, through system linkage and polling detection, can accurately locate one or more coverage units that cause self-oscillation, achieving precise localization of the self-oscillation source. It then adjusts the gain of the self-oscillation source coverage unit only, avoiding a one-size-fits-all gain attenuation across the entire system and maximizing the overall coverage performance of the system. By effectively eliminating self-oscillation, it ensures that each stage of the system's amplifiers operates in the linear region, thereby ensuring the gain and quality of the signal within the coverage area and effectively improving the user's communication experience.

[0037] The entire self-oscillation detection and elimination process of the method of the present invention is completed automatically by the system without manual intervention, which can greatly reduce the debugging difficulty for on-site construction personnel and reduce the reliance on the professional skills of maintenance personnel.

[0038] In an embodiment of the present invention, a micro-distributed repeater coverage system is also provided, characterized in that it includes: Main control unit 100 is used for wireless or wired coupling of base station signals; An expansion unit 200 is provided, and at least one expansion unit 200 is provided. The expansion unit is connected to the main control unit via an RF cable. Coverage unit 300 is connected to extension unit 200 via radio frequency cable and is used to amplify and cover the signal; The main control unit is configured to execute the method in the above embodiments, including performing self-excitation detection when a predetermined self-excitation detection trigger condition occurs, sending an instruction to a target coverage unit in the coverage unit 300, and controlling the target coverage unit to transmit a preset test signal. Receive test signals transmitted by the target coverage unit and propagated to the main control unit 100 via a spatial path; Based on the strength of the received test signal, the spatial path loss between the transmitting antenna of the target coverage unit and the receiving antenna of the main control unit 100 is calculated. The spatial path loss is compared with the system gain threshold to determine whether the target coverage unit is a self-excitation source coverage unit that causes system self-excitation. When the target coverage unit is determined to be a self-excited source coverage unit, a gain adjustment command is sent to the corresponding coverage unit to reduce the gain and eliminate self-excitement.

[0039] Reference Figure 3 The main control unit 100 mainly includes multiple operating frequency band amplification links, a central processing unit, an FSK communication module, as well as Bluetooth, WiFi, and LTE communication modules for device monitoring and management. Reference Figure 4 The internal structure of the coverage unit 300 is similar to that of the main control unit 100, and it also includes amplification links for multiple frequency bands, a CPU, and an FSK communication module. Reference Figure 5 The expansion unit 200 contains a CPU, an FSK communication module, and a signal distribution link. The expansion unit can remotely power the main control unit and the coverage unit via RF cables. Each output port of the expansion unit can integrate a digitally controlled attenuator (ATT). The main control unit 100, the expansion unit 200, and the coverage unit 300 communicate with each other through the CPU and the FSK module in-band or out-of-band to enable command issuance and information reporting.

[0040] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0041] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for automatically eliminating self-excitation in a micro-distributed repeater coverage system, based on a distributed repeater coverage system including a main control unit, an extension unit, and a coverage unit, characterized in that, The method includes the following steps: Step 1: Under the predetermined self-excitation detection trigger conditions, the main control unit performs self-excitation detection; Step 2: The main control unit sends a command to one of the target coverage units among the multiple coverage units, controlling the target coverage unit to transmit a preset test signal; Step 3: The main control unit receives the test signal propagated through the spatial path; Step 4: The main control unit calculates the spatial path loss between the target coverage unit and the main control unit based on the received test signal strength; Step 5: The main control unit compares the calculated spatial path loss with the system gain threshold to determine whether the target coverage unit is a self-excitation source coverage unit that causes system self-excitation; Step 6: If the target coverage unit is determined to be a self-oscillating source coverage unit, the main control unit sends a gain adjustment command to the target coverage unit to reduce the gain of the target coverage unit to eliminate self-oscillation.

2. The method for automatically eliminating self-excitation in a micro-distributed repeater coverage system according to claim 1, characterized in that, The predetermined self-oscillation detection trigger conditions include: the self-oscillation detection function of the micro-distributed repeater coverage system is activated or the micro-distributed repeater coverage system restarts from a power-off state.

3. The method for automatically eliminating self-excitation in a micro-distributed repeater coverage system according to claim 1, characterized in that, The main control unit selects a coverage unit that has not yet been detected as a new target coverage unit according to a preset order, and repeats steps 2 to 5 until all coverage units are traversed or all coverage units are located.

4. The method for automatically eliminating self-excitation in a micro-distributed repeater coverage system according to claim 1, characterized in that, In step 5, the system gain threshold is determined based on the system's real-time gain, and the main control unit calculates the system's real-time gain using the following formula: System real-time gain = main control unit gain + coverage unit gain - (main control unit output power - coverage unit received power); When the spatial path loss is less than the system real-time gain, the target coverage unit is identified as a self-excited source coverage unit.

5. The method for automatically eliminating self-excitation in a micro-distributed repeater coverage system according to claim 4, characterized in that, Step 6 specifically includes the following steps: Based on the frequency of the test signal and the calculated spatial path loss, the spatial distance between the target coverage unit and the main control unit is inferred. Based on the calculated spatial distance and the frequency of the system's operating frequency band, the actual spatial path loss under each operating frequency band is calculated. Based on the actual spatial path loss and real-time system gain in each operating frequency band, the target gain attenuation value that needs to be set for the self-excited source coverage unit is calculated, and the gain adjustment command is generated. The target gain attenuation value is calculated using the following formula: Target gain attenuation value = System real-time gain - Spatial path loss.

6. The method for automatically eliminating self-excitation in a micro-distributed repeater coverage system according to claim 4, characterized in that, When the spatial path loss is less than the system real-time gain minus a preset margin value, the target coverage unit is determined to be a self-excited source coverage unit.

7. The method for automatically eliminating self-excitation in a micro-distributed repeater coverage system according to claim 4, characterized in that, Step 6, the method for reducing the gain of the target coverage cell, further includes: Set the target coverage cell gain to the preset minimum gain value; The gain of the target coverage unit is gradually increased using a preset step value. After each rebound, a new self-excitation judgment is performed; Until a self-excited loop is detected, the gain of the target coverage unit is backed down by one step value.

8. A micro-distributed repeater coverage system for automatically eliminating self-oscillation, characterized in that, include: The main control unit is used for wireless or wired coupling of base station signals; An expansion unit is provided, at least one of which is connected to the main control unit; A coverage unit, connected to the expansion unit, is used to amplify and cover the signal; The main control unit is configured to perform the method as described in any one of claims 1 to 7.

9. The micro-distributed repeater coverage system for automatic self-oscillation elimination according to claim 8, characterized in that, The main control unit, expansion unit, and coverage unit each include a CPU unit and an FSK communication module; the preset test signal adopts the FSK waveform transmitted through the FSK communication module of the target coverage unit.

10. The micro-distributed repeater coverage system for automatic self-oscillation elimination according to claim 8, characterized in that, The main control unit also includes at least one of a Bluetooth communication module, a WiFi communication module, and an LTE communication module.

Images