Digital program control dispatcher with hierarchical impedance self-healing function and control method

Abstract

The invention discloses a digital program control dispatcher with a hierarchical impedance self-healing function and a control method, and the dispatcher comprises a business board which is provided with a mixed impedance self-adaptive matching circuit which is connected in series between a port driving chip and an external physical interface. The circuit is formed by connecting a passive self-adaptive matching unit close to an interface side and a digital control matching unit close to a driving side in series. The passive unit is used for performing nanosecond instantaneous passive matching on load impedance abrupt change based on a nonlinear transmission line principle; the digital unit carries out injection detection, analysis modeling and control of a programmable passive network, and carries out precise matching on slow-changing impedance. And through cooperation of the two, full-time-domain and high-precision impedance self-adaption from instant to long term is realized. According to the invention, the problem that the response speed, the matching precision, the reliability and the cost are difficult to consider at the same time in the prior art is solved, and the signal integrity, the equipment reliability and the economical efficiency of the communication port in a complex environment are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of communication network equipment technology, and more specifically, to impedance matching and signal integrity protection technology for the physical layer interfaces of devices such as digital program-controlled dispatchers and base station radio frequency units. Background Technology

[0002] These devices connect to remote equipment via various cables. Their core objective is to ensure efficient and distortion-free signal transmission between the port and the external line. This requires the port's output impedance to match the line's characteristic impedance as closely as possible to minimize signal reflection. To achieve this goal, existing technologies generally employ two approaches. The first is a fixed matching network approach, where a fixed network of resistors, capacitors, and inductors is used for factory pre-matching at the port. While this approach is simple and inexpensive, its matching effect is optimal only under specific loads and frequencies. It cannot adapt to the slow, time-varying load impedance caused by cable aging, connector oxidation, environmental changes, etc., making it a static, open-loop, passive approach lacking self-healing capabilities. The second approach is an active impedance tuning system approach, which integrates impedance sensors, adjustable matching networks (such as those based on varactor diodes or RFMEMS), and control algorithms to form a closed loop for real-time detection and adjustment. Although this solution can adapt dynamically, it has inherent defects: its response speed is limited by the signal detection, processing and driving delay, which is usually at the millisecond level or above, and it cannot effectively suppress impedance changes at the nanosecond / microsecond level such as insertion and removal transients and lightning strike induction; at the same time, the system is highly complex and expensive, and its long-term reliability is limited by software stability and the lifespan of movable components.

[0003] Therefore, within the existing technological framework, communication equipment port impedance management faces a binary dilemma: simple but rigid, and intelligent but complex and slow. A comprehensive solution that can balance instantaneous rapid response with long-term accurate matching, while also possessing high reliability and reasonable cost, is lacking. This technological bottleneck restricts the long-term stable operation of equipment in complex real-world environments. Improving this bottleneck and designing an innovative hybrid impedance adaptive architecture has become a pressing technical problem to be solved in this field. Summary of the Invention

[0004] To address the problems existing in the port impedance matching technology of digital programmable schedulers, this invention provides a digital programmable scheduler and control method with graded impedance self-healing function, which simultaneously achieves high-performance matching to resist transient disturbances and slow drift, significantly improving system reliability and signal quality while effectively controlling hardware cost and power consumption.

[0005] The solution to the technical problem of this invention is as follows: A digital programmable scheduling machine with graded impedance self-healing function is employed, comprising a scheduling machine body, at least one service board, wherein the service board is provided with a port driver chip, an external physical interface, and a hybrid impedance adaptive matching circuit connected in series between the port driver chip and the external physical interface; the hybrid impedance adaptive matching circuit includes: a passive adaptive matching unit, which is composed of a nonlinear transmission line loaded with a nonlinear element, used to passively adjust its equivalent characteristic impedance through nonlinear effects in response to signal voltage changes caused by changes in port load impedance, so as to perform instantaneous coarse matching for impedance changes; and a digital control matching unit. It includes a detection module, a control module, and a programmable passive compensation network. The detection module is used to inject detection signals into the external lines connected to the external physical interface and obtain feedback signals. The control module is used to establish an impedance model based on the feedback signals and generate control commands. The programmable passive compensation network is used to switch its internal impedance branches according to the control commands to accurately match the port impedance. The passive adaptive matching unit is connected in series with the digital control matching unit. The passive adaptive matching unit is located closer to the external physical interface, and the digital control matching unit is located closer to the port driver chip. The two work together to achieve hierarchical impedance matching.

[0006] Preferably, the nonlinear element in the nonlinear transmission line is a varactor diode, and at least some of the varactor diodes are connected between the signal path and ground in anti-parallel pairs; the nonlinear transmission line also includes a bias network for providing a DC bias voltage to the varactor diodes.

[0007] Preferably, the control module is also connected to the bias network for dynamically adjusting the magnitude of the DC bias voltage according to the impedance model or signal quality index, so as to optimize the nonlinear operating point of the passive adaptive matching unit.

[0008] Preferably, the programmable passive compensation network includes an impedance matrix composed of resistors and capacitors and a gating circuit controlled by a switch array, wherein the switch array is controlled by the control module and reconstructs the compensation impedance by gating different combinations of components.

[0009] Preferably, the control module executes a hysteresis control algorithm. When the slow-changing component of the external line impedance is detected to exceed a first threshold, the digital control matching unit is activated for precise matching. When the fast-changing component of the impedance is detected to exceed a second threshold, the passive adaptive matching unit responds instantaneously. The first threshold is greater than the second threshold.

[0010] Preferably, when injecting a detection signal, the detection module uses a short-time pulse or orthogonal pseudo-random code sequence with a frequency higher than the voice frequency band, and couples it to an external line through an isolation unit to isolate the DC power supply signal and the high-voltage ringing signal.

[0011] Preferably, it also includes a ringing monitoring unit for monitoring the ringing signal on the user interface circuit; when a high-voltage ringing signal is detected, the control module controls the detection module to stop working and locks the current state of the programmable passive compensation network, while keeping the passive adaptive matching unit working normally.

[0012] A hierarchical impedance adaptive matching method for a digital programmable scheduling machine is provided. The method includes: using a passive adaptive matching unit to instantaneously respond to signal voltage changes caused by load impedance variations, passively adjusting the equivalent characteristic impedance to achieve a first-level coarse matching; periodically or triggerfully injecting probe signals through a digitally controlled matching unit to obtain the impedance characteristics of the external line, and then driving a programmable passive compensation network to reconstruct the impedance after analysis by a control module, achieving a second-level precise matching; wherein the first-level coarse matching and the second-level precise matching work together to continuously maintain the reflection coefficient seen from the port driver chip within a preset range.

[0013] Preferably, during the second-stage precise matching process, the control module simultaneously adjusts the DC bias voltage of the passive adaptive matching unit based on the impedance modeling results to optimize its nonlinear operating range.

[0014] Preferably, the method further includes: monitoring the impedance change rate of the external line; when the change rate exceeds a set value, preferentially relying on the passive adaptive matching unit for matching; when the impedance value deviates from the set range by more than a threshold, activating the digital control matching unit for matching.

[0015] The beneficial effects of this invention are as follows: 1. By combining passive transient response at the physical layer with precise calibration in the digital domain, full-time domain coverage of impedance disturbances is achieved. This nanosecond-level buffering and high-precision calibration capability ensures that the port reflection coefficient (such as VSWR) remains at an excellent level under various dynamic conditions, fundamentally improving signal transmission quality.

[0016] 2. This architecture delivers structural reliability gains and cost reductions. The passive unit, acting as the first line of defense, is composed of highly reliable passive components, absorbing most transient shocks and protecting subsequent circuits, significantly improving the overall system MTBF. Simultaneously, this hybrid approach avoids the use of expensive high-frequency continuously adjustable devices and complex analog front-ends, relying primarily on standard passive components and digital control. This results in a projected 50%-70% reduction in single-port hardware cost compared to a performance-equivalent fully active analog solution. Furthermore, intelligent cooperative strategies (such as dynamic biasing and predictive matching) reduce the operating frequency of the digital unit, optimizing the system's average power consumption by over 30%.

[0017] 3. The deep optimization features revealed in the implementation (such as dynamic bias adjustment, adaptive filtering, and predictive matching based on historical data) enable the system to transcend the basic reactive operating mode. The system can adaptively optimize its parameters based on line conditions and historical patterns, and predict and smoothly adjust in advance, thereby avoiding signal disturbances that may be introduced by the matching action itself, exhibiting stronger robustness in complex electromagnetic noise environments. This lays a solid foundation for applying this technology to high-end communication and measurement scenarios with extremely stringent requirements for signal continuity and purity. Attached Figure Description

[0018] Figure 1 It is a block diagram that illustrates the overall system architecture and signal flow of the invention.

[0019] Figure 2 It discloses the schematic diagram of the specific circuit of the passive adaptive matching unit.

[0020] Figure 3 It discloses the schematic diagram of the specific circuit of the programmable compensation network in the digital control matching unit.

[0021] Figure 4 This is a flowchart illustrating the hierarchical matching control method. Detailed Implementation

[0022] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of protection of the present invention.

[0023] As a core node in the communication network, the digital program-controlled dispatching machine's various interfaces (such as E1, FXO, and FXS) deployed in high density on its service boards need to be connected to remote devices via long-distance cables. In actual deployment environments, factors such as cable aging, connector oxidation, temperature and humidity changes, and replacement of connected equipment can cause the ports to exhibit time-varying and complex load impedance characteristics. This impedance mismatch can cause severe signal reflection, leading to waveform distortion, increased bit error rate (BER), and potentially causing overstress in the drive circuit, ultimately affecting call quality and system reliability. This invention is an innovative solution proposed to address this technical bottleneck.

[0024] Example 1: A hardware architecture for a digital programmable scheduling machine with hierarchical impedance self-healing function, referring to... Figure 1This diagram illustrates the overall architecture and position of a hybrid impedance adaptive matching circuit 100 for a single service port in the digital programmable scheduling machine of the present invention, along with its location in the signal link. The circuit 100 is connected in series between the port driver chip 101 and the external physical interface 102 (e.g., RJ48c). The core feature of the hybrid impedance adaptive matching circuit 100 is its two-stage structure connected in series. The sequence is as follows: starting from the port driver chip 101 side, the circuit consists of a digital control matching unit 110 and a passive adaptive matching unit 120, ultimately connecting to the external physical interface 102. This series sequence (digital control unit first, passive unit second) is the key topology for achieving efficient hierarchical matching in this embodiment. The digital control matching unit 110 specifically includes a detection module 111, a control module 112, and a programmable passive compensation network 113. The core of the detection module 111 is a high-precision, low-power digital-to-analog / analog-to-digital converter and coupling circuit. Preferably, this module employs a detection method based on orthogonal pseudo-random codes such as m-sequences. The DAC generates an m-sequence signal with a frequency higher than the voice band, such as 100kHz to 2MHz, which is injected into the main signal path through a highly directional miniature directional coupler 114. The same coupler 114 collects reflected signals from external lines, samples them with an ADC, and sends them to the control module 112. The introduction of the coupler 114 isolates the probe signal from the service signal and DC power (if any). The control module 112 is implemented by a microcontroller (MCU) with a built-in digital signal processor (DSP) core. It receives the reflected signal sampled by the ADC and extracts the complex impedance information (amplitude and phase) of the line through correlation operations. Based on this, the MCU runs an impedance modeling algorithm (e.g., establishing a simplified model equivalent to a resistor and capacitor in parallel) and calculates the compensation required to pull the total port impedance back to the nominal value (e.g., 120Ω). The programmable passive compensation network 113 is essentially an impedance matrix consisting of a precision resistor array R, a capacitor array C, and analog switches such as CMOS switches or relays. The switch array is controlled by the MCU's GPIO pins. Based on the calculated compensation amount, the MCU generates a set of control commands, i.e., combinations of on / off switches, to select specific R and C components to connect between the signal path and ground, thereby reconstructing a passive network with the required impedance value. For example, the network can provide series resistance compensation from 75Ω to 150Ω in 5Ω steps, and parallel capacitance compensation from -100pF to +100pF.

[0025] The passive adaptive matching unit 120 corresponds to the passive adaptive matching unit, the core of which is a nonlinear transmission line (NLTL) loaded with a varactor diode. The structure and connections are as follows: Figure 2As shown, four pairs of anti-parallel silicon varactor diodes 122 are periodically distributed and loaded on a microstrip line 121 with a characteristic impedance of Z0. The midpoint of each pair of diodes is connected to an adjustable DC bias network 124 via an RF choke (RFC) 123. The bias network 124 provides a DC voltage Vbias ranging from 0V to 10V. This unit is positioned closer to the external interface 102. The transient response principle is based on the fact that when a rapid change occurs in the external load (e.g., a microsecond-level insertion / removal transient), the signal voltage distribution on the transmission line changes drastically. This voltage acts directly on the varactor diodes 122, causing their junction capacitance to change instantaneously. This distributed capacitance change automatically fine-tunes the equivalent characteristic impedance of the entire structure within nanoseconds through the nonlinear effect of the transmission line, absorbing and initially suppressing the sudden change and preventing reflected waves from impacting the upstream circuitry (especially the digital control unit). This process is completely passive and requires no control commands.

[0026] Regarding the cooperative working mechanism, the digital control unit 110 is responsible for handling slow, continuous impedance drift, such as a slow increase in resistance due to oxidation. It periodically initiates detection, for example, once per second, or when a mismatch exceeds a threshold, to achieve precise matching in steady state through accurate calculation and reconstruction of the compensation network 113. Figure 3 As shown, the programmable passive compensation network 113 is an impedance matrix composed of a precision resistor R, a capacitor C array, and analog switches. In one example, the signal path is equipped with series compensation resistors R_comp (e.g., R1-R3) controlled by switches S1_R and S2_R, and parallel compensation capacitors C_comp (e.g., C1-C2) controlled by switch S_C. By driving different switch combinations through the control module 112, the required compensation impedance can be reconstructed. The passive unit 120 acts as a physical firewall, specifically to deal with transient disturbances that the digital control loop cannot respond to in time. The two-stage series connection first uses the passive unit 120 for rapid coarse adjustment and buffering, and then the digital unit 110 for precise fine adjustment, jointly ensuring that the reflection coefficient seen from the driver chip 101 can be maintained at a low level under various operating conditions, for example, the voltage standing wave ratio (VSWR) remains below 1.5. Figure 4 As shown in the flowchart, the digital control unit 110 and the passive adaptive unit 120 follow a set of cooperative control logic. The passive unit 120 operates continuously, performing instantaneous coarse adjustments for rapid mutations (corresponding to flowchart S41); the digital unit 110 is activated when trigger conditions are met (such as the cycle reaching its end or slow mismatch exceeding the threshold, corresponding to judgment block S42), performing detection, calculation, and precise fine adjustments (corresponding to flowchart blocks S43-S45). The two stages are connected in series, with buffering followed by calibration, to jointly ensure stable port matching.

[0027] Building upon the basic hierarchical architecture, the system performance and intelligence can be further enhanced by introducing more refined collaborative control strategies. For example, collaborative optimization of dynamic bias and adaptive filtering represents a deepening and expansion of this approach. Control module 112 not only controls compensation network 113 but also connects to and dynamically adjusts the voltage Vbias of the bias network 124 of passive unit 120. Specifically, the MCU runs an optimization algorithm based on its established real-time impedance model and signal quality indicators monitored from the service signals, such as eye diagram opening estimation and bit error rate (BER) trend. The goal of this algorithm is to find the Vbias value that optimizes the overall system performance. For example, when a large capacitive component of the line impedance is detected, the algorithm may appropriately reduce Vbias, causing the varactor diode to operate in a region with a large capacitance value to better compensate for capacitive mismatch.

[0028] Preferably, a digital bandpass filter controlled by an MCU is inserted after the ADC of the detection module 111 and before the impedance calculation. The center frequency and bandwidth of this filter can be adaptively adjusted according to the spectrum of the currently injected detection signal and the monitored line noise spectrum. When there is strong interference at a specific frequency in the line, the filter can automatically notch the signal, thereby significantly improving the signal-to-noise ratio and accuracy of the impedance measurement, ensuring that the precise matching capability of the digital control unit remains reliable even in harsh noise environments. This synergy of dynamic bias and adaptive filtering upgrades the passive unit 120 from a completely fixed buffer to a semi-active regulator whose performance can be optimized to a limited extent. It allows the system to pre-adjust the passive unit to a better operating point based on long-term impedance change trends, thereby reducing the compensation pressure on the subsequent digital unit 110, and even reducing the activation frequency of the digital unit in some slowly changing scenarios, thus reducing the overall power consumption of the system. The adaptive filter directly improves the robustness of the system in complex electromagnetic environments.

[0029] Furthermore, predictive matching based on impedance change history learning is a forward-looking intelligent feature. Control module 112 continuously records historical measurement data of the external line impedance (including values, rates of change, time stamps, etc.) and constructs a lightweight time-domain model. Specifically, the MCU uses the recorded data to identify certain patterns or periodicities in impedance changes (e.g., regular fluctuations related to diurnal temperature variations). Based on this, it can predict the possible future impedance trends in the near future. In application, before predicting that the impedance will drift in a certain direction and potentially trigger the matching action threshold, control module 112 can adjust the configuration of the programmable passive compensation network 113 and the bias voltage Vbias of the passive unit 120 in advance and smoothly, synchronizing the change in matching state with the predicted change in impedance. This achieves an evolution from reactive matching to predictive matching. Predictive matching completely avoids the instantaneous mismatch window caused by matching action lag, making the port matching state seamless and always optimal from the perspective of an external observer. This is particularly beneficial for services with extremely high requirements for signal continuity (such as high-precision clock transmission and lossless audio), further reducing the risk of jitter introduced by the impedance management process itself.

[0030] Through the above specific implementation, since the passive adaptive matching unit 120 operates based on physical effects, its response time to impedance changes is within 10 nanoseconds, successfully filling the gap in transient disturbance suppression that traditional digital active systems (response time > 1 millisecond) cannot cover. Meanwhile, the digital control matching unit 110 can correct slowly changing impedances with an accuracy better than 1%. The synergy of both enables the port to possess excellent impedance adaptability across the entire timescale (from nanosecond-level transients to long-term drifts of months to years). When a step change occurs in the analog load impedance, traditional pure digital solutions exhibit high-amplitude, long-lasting mismatch peaks; while pure passive NLTL solutions can quickly suppress these peaks, they have significant steady-state residual errors. The hybrid solution of this invention almost eliminates transient spikes and can quickly and accurately recover to the optimal matching state, demonstrating that the hybrid architecture achieves significant superiority in both response speed and steady-state accuracy. The passive unit 120, as the first line of defense, is composed of robust passive components and has no failure modes. It absorbs most transient shocks, protecting the relatively vulnerable digital detection and switching circuits downstream. The programmable network in digital unit 110 employs passive resistors, capacitors, and switches, making it more reliable than continuously adjustable analog devices (such as variable capacitors). This passive buffer + digital configuration architecture is expected to improve the overall system MTBF (Mean Time Between Failures) by more than three times compared to traditional fully active analog tuning solutions. Passive unit 120 has extremely low cost (primarily PCB and diodes). Digital unit 110 eliminates the need for expensive vector network analyzer-level RF front-ends, requiring only a medium-precision DAC / ADC and a low-cost MCU, resulting in a cost far lower than high-performance analog tuning solutions. It is estimated that the single-port hardware cost of this hybrid solution is approximately 50%-70% lower than that of a fully active analog solution achieving equivalent matching performance and response speed, while simultaneously achieving higher reliability. Through intelligent strategies such as dynamic biasing, adaptive filtering, and predictive matching, the system can dynamically allocate workload according to actual conditions. During periods of impedance stability, the digital unit can reduce the probe frequency or enter a low-power mode, with the optimized passive unit providing the primary matching function, thereby reducing the average system power consumption by more than 30%.

[0031] It should be noted that the above embodiments and accompanying drawings are merely illustrative examples of the core principles and key structures of the digital programmable scheduling machine and control method of the present invention. The accompanying drawings are simplified schematic diagrams, intended to clearly illustrate the structural, process, or data flow relationships related to the innovative points of the technical solution, and are not intended to limit the complete form of the actual product. This specification focuses on the innovative technical means necessary to achieve the invention's objectives and solve the technical problems. While auxiliary or commonly known details such as PCB layout of the business board, specific microcontroller model selection, power management circuits, software driver code framework, structural heat dissipation and shielding, which can be implemented by those skilled in the art without creative effort, are not described in detail, they should all be understood as naturally included in the specific implementation of the present invention and fall within the protection and implementation scope of this technical solution.

Claims

1. A digital programmable scheduling machine with graded impedance self-healing function, comprising a scheduling machine body, characterized in that, It also includes at least one service board, which is provided with a port driver chip, an external physical interface, and a hybrid impedance adaptive matching circuit connected in series between the port driver chip and the external physical interface. The hybrid impedance adaptive matching circuit includes: A passive adaptive matching unit consists of a nonlinear transmission line loaded with a nonlinear element. In response to changes in signal voltage caused by changes in port load impedance, the nonlinear element passively adjusts its equivalent characteristic impedance through nonlinear effects to perform instantaneous coarse matching of impedance changes. The digital control matching unit includes a detection module, a control module, and a programmable passive compensation network. The detection module is used to inject a detection signal into the external line connected to the external physical interface and obtain a feedback signal. The control module is used to establish an impedance model based on the feedback signal and generate control commands. The programmable passive compensation network is used to switch its internal impedance branches according to the control commands to accurately match the port impedance. The passive adaptive matching unit is connected in series with the digital control matching unit. The passive adaptive matching unit is located closer to the external physical interface, and the digital control matching unit is located closer to the port driver chip. The two work together to achieve graded impedance matching.

2. The digital programmable scheduling machine according to claim 1, characterized in that, The nonlinear element in the nonlinear transmission line is a varactor diode, and at least some of the varactor diodes are connected between the signal path and ground in anti-parallel pairs; the nonlinear transmission line also includes a bias network for providing a DC bias voltage to the varactor diodes.

3. The digital programmable scheduling machine according to claim 2, characterized in that, The control module is also connected to the bias network and is used to dynamically adjust the magnitude of the DC bias voltage according to the impedance model or signal quality index in order to optimize the nonlinear operating point of the passive adaptive matching unit.

4. The digital programmable scheduling machine according to claim 1, characterized in that, The programmable passive compensation network includes an impedance matrix composed of resistors and capacitors and a gating circuit controlled by a switch array. The switch array is controlled by the control module and reconstructs the compensation impedance by gating different combinations of components.

5. The digital programmable scheduling machine according to claim 1, characterized in that, The control module executes a hysteresis control algorithm. When the slow-changing component of the external line impedance is detected to exceed the first threshold, the digital control matching unit is activated for precise matching. When the fast-changing component of the impedance is detected to exceed the second threshold, the passive adaptive matching unit responds instantaneously. The first threshold is greater than the second threshold.

6. The digital programmable scheduling machine according to claim 1, characterized in that, When injecting a detection signal, the detection module uses a short-time pulse or orthogonal pseudo-random code sequence with a frequency higher than the voice frequency band, and is coupled to an external line through an isolation unit to isolate the DC power supply signal and the high-voltage ringing signal.

7. The digital programmable scheduling machine according to claim 1, characterized in that, It also includes a ringing monitoring unit for monitoring ringing signals on the user interface circuit; when a high-voltage ringing signal is detected, the control module controls the detection module to stop working and locks the current state of the programmable passive compensation network, while keeping the passive adaptive matching unit working normally.

8. A hierarchical impedance adaptive matching method for a digital programmable timer, characterized in that, Applied to the digital programmable scheduling machine as described in any one of claims 1 to 7, the method comprises: The passive adaptive matching unit provides an instantaneous response to signal voltage changes caused by load impedance variations, passively adjusting the equivalent characteristic impedance to achieve the first-stage coarse matching. By periodically or triggerably injecting detection signals through a digitally controlled matching unit, the impedance characteristics of the external line are obtained. After analysis by the control module, the programmable passive compensation network is driven to reconstruct the impedance, thereby achieving the second-stage precise matching. The first-level coarse matching and the second-level precise matching work together to keep the reflection coefficient seen from the port driver chip within a preset range.

9. The method according to claim 8, characterized in that, During the second-stage precise matching process, the control module simultaneously adjusts the DC bias voltage of the passive adaptive matching unit based on the impedance modeling results to optimize its nonlinear operating range.

10. The method according to claim 8, characterized in that, The method further includes: monitoring the impedance change rate of the external line; when the change rate exceeds a set value, preferentially relying on the passive adaptive matching unit for matching; when the impedance value deviates from the set range and exceeds a threshold, activating the digital control matching unit for matching.

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