Receiving end test device of OLT optical module

Abstract

The invention relates to the technical field of signal testing, in particular to a receiving end testing device of an OLT optical module. Comprising at least four independent error code test units capable of working in parallel, and is used for generating a high-speed test signal and analyzing the error rate of a receiving end; a burst signal control module which is connected with the multi-channel continuous error code test module and is used for dynamically generating a burst control signal, a reset signal and a trigger signal corresponding to each channel and realizing synchronous calibration of the multi-channel error code test through sequential control; and the protocol adaptive module is embedded in the burst signal control module and automatically configures a burst period, an optical power threshold value and a reset time sequence according to a GPON / XGPON / XGSPON protocol. The receiving end test equipment of the OLT optical module can realize efficient test and is relatively low in test cost.

Description

Technical Field

[0001] The present invention relates to the technical field of signal testing, and in particular to a receiving end testing device for an OLT optical module. Background Art

[0002] With the rapid development of fiber-optic access network technology, OLT optical modules, as core components, have a significant impact on network transmission quality due to their receiver performance. Traditional testing solutions primarily rely on single-channel continuous bit error testers (BERTs) combined with manual calibration equipment. This approach suffers from the following drawbacks: existing equipment only supports sequential testing of single channels, failing to meet the mass production requirements of multi-channel OLT optical modules. OLT optical modules must respond to burst signals from ONUs within microseconds, but traditional equipment uses fixed delay parameters, resulting in insufficient calibration accuracy and an inability to accurately simulate real-world OLT operating scenarios. Different PON protocols, such as GPON and XGSPON, have significantly different requirements for burst period and optical power dynamic range. Existing technologies rely on specialized hardware, requiring expensive equipment upgrades to adapt to different protocols. Furthermore, existing solutions require the combination of multiple devices, including a continuous bit error tester, a burst bit error tester, and an optical power meter. This results in high system complexity, a large footprint, and hardware costs exceeding $200,000, severely hindering technology upgrades for small and medium-sized manufacturers.

[0003] Based on the above problems, there is an urgent need for a receiving end test device for OLT optical modules that can achieve efficient testing and low testing costs. Summary of the Invention In view of the current need to use a combination of multiple devices such as a continuous bit error tester, a burst bit error tester and an optical power meter, which leads to high system complexity and large footprint, the present application provides an OLT optical module receiving end test device to solve the above problems.

[0004] An OLT optical module receiving end test device, comprising: Multi-channel continuous error rate test module: Contains at least four independent error rate test units that can operate in parallel, used to generate high-speed test signals and analyze the bit error rate at the receiving end; Burst signal control module: connected to the multi-channel continuous error code test module, used to dynamically generate burst control signals, reset signals and trigger signals corresponding to each channel, and realize synchronous calibration of multi-channel error code test through timing control; The protocol adaptation module is embedded in the burst signal control module and automatically configures the burst period, optical power threshold, and reset timing according to the GPON / XGPON / XGSPON protocol.

[0005] Adopting the above technical solution: This patent can solve the problems of low efficiency of traditional single-channel test equipment and inability to support multi-channel parallel testing; different PON protocols require hardware replacement, resulting in high costs and poor flexibility. The multi-channel parallel error test unit can achieve 4-channel parallel testing to improve test efficiency, and the protocol adaptation module is compatible with GPON / XGPON / XGSPON, without the need for hardware replacement, and the equipment reuse rate is increased by 100%.

[0006] Preferably, the multi-channel continuous bit error test module includes: Pattern generator unit, used to generate programmable PRBS test patterns; Clock and data recovery unit, used to extract clock and data from the receiving end signal of the OLT optical module; The error statistics unit calculates the bit error rate by comparing the transmitted pattern with the received data.

[0007] Adopting the above technical solution: the above solution refines the multi-channel continuous error test module, and can realize testing of at least four independent error test units that can work in parallel at a time.

[0008] Further preferably, the burst signal control module includes: Four independent BEN signal output ports, used to control the on / off status of the ONU light source; Four-way LOS / SD signal acquisition ports for monitoring the loss of signal and signal detection status of optical modules; Four-way Triger signal output port, used to trigger burst optical power sampling; Four reset signal output ports, used to reset the optical module receiving end logic.

[0009] Adopting the above technical solution: the above solution refines the burst signal control module into multiple signal output ports and the corresponding functions of each port.

[0010] Further preferably, the burst signal control module adopts a two-stage delay compensation mechanism, including: The first-level fixed delay compensation circuit is used to eliminate the transmission delay of the physical link; The second-level dynamically adjustable delay module dynamically corrects the synchronization deviation between the burst control signal and the trigger signal based on the correction formula; The correction formula is: , in, is the channel characteristic coefficient, is the reference offset, is the rising edge time of the BEN signal, is the measured Triger signal arrival time.

[0011] Adopting the above technical solution: The above solution can solve the problem that traditional equipment adopts fixed delay compensation and cannot eliminate dynamic deviation in signal transmission. The first-level delay compensation can eliminate physical link delay, and the second-level dynamic adjustment formula compensates for dynamic deviation. It can achieve precise compensation through quantization parameters (α, β) and adapt to different channel characteristics.

[0012] Further preferably, the steps of calculating the channel characteristic coefficient and the reference offset are: Inject a standard burst signal into the optical module to be tested and measure the actual response time of the Triger signal ; Target time according to the agreement , calculate the combination of the optimal channel characteristic coefficient and the reference offset according to the iterative formula; The iterative formula is: .

[0013] Adopting the above technical solution: The above solution can solve the problem that manual calibration of burst timing parameters is inefficient and relies on operator experience. The above solution ensures the global optimal solution of compensation parameters α and β through mathematical optimization, ensuring that the calibration accuracy error is less than 0.1 ns.

[0014] Further preferably, the error statistics unit adopts a double-window comparison algorithm: The first statistical window calculates the original bit error rate according to a fixed period ; The second statistical window dynamically adjusts the window length according to the valid data segment of the burst signal to calculate the effective bit error rate , and discard invalid data segments; The final bit error rate output is .

[0015] Adopting the above technical solution: The above solution can solve the problem that the fixed statistical window cannot distinguish between valid / invalid data segments in the burst signal, resulting in a long low bit error rate test time. This solution adopts a dual-window comparison algorithm to effectively shorten the bit error rate statistics time by 60%.

[0016] Further preferably, the burst signal control module introduces random jitter interference into the reset signal and verifies the anti-interference capability of the optical module, and the steps of verifying the anti-interference capability of the optical module are: The reset signal falls on the edge of the superposition of the normal distribution The time jitter of It is an adjustable parameter of 1-50ns; Statistical bit error rate change ΔBER, if ΔBER>10-3 The optical module is judged to be unqualified for anti-interference.

[0017] The above technical solution can solve the problem of optical module anti-interference capability lacking quantitative testing standards and relying on engineers' experience and judgment. The normally distributed random jitter interference used in this solution simulates real-world interference and can improve the anti-interference test coverage. The calculation of the statistical bit error rate change can also clarify the quantitative standard.

[0018] Further preferably, the multi-channel continuous error code test module adopts a channel cross-validation mechanism: Channel A sends the standard PRBS pattern, and channel B receives it and calculates the bit error rate. Switch the channel roles and repeat the test. If the difference in the two bit error rates exceeds 10%, the hardware self-test procedure is triggered.

[0019] Adopting the above technical solution: The above solution can solve the problem that single-channel testing cannot identify hardware errors; and the channel cross-validation mechanism can improve the hardware fault detection rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a block diagram of the receiving end test equipment for the OLT optical module of this application; Figure 2 This is the block diagram of the multi-channel continuous bit error test module for this application. DETAILED DESCRIPTION

[0022] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0023] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0024] See also Figure 1-Figure 2 Conventional optical module receiver test equipment, for example, uses a combination of continuous bit error testers, burst bit error testers, and optical power meters to perform bit error testing. This approach increases system complexity, floor space, and hardware costs, as well as low test efficiency. To address these issues, the present application provides an OLT optical module receiver test device, comprising: Multi-channel continuous error rate test module: Contains at least four independent error rate test units that can operate in parallel, used to generate high-speed test signals and analyze the bit error rate at the receiving end; Burst signal control module: connected to the multi-channel continuous error code test module, used to dynamically generate burst control signals, reset signals and trigger signals corresponding to each channel, and realize synchronous calibration of multi-channel error code test through timing control.

[0025] The protocol adaptation module is embedded in the burst signal control module and automatically configures the burst period, optical power threshold, and reset timing according to the GPON / XGPON / XGSPON protocol.

[0026] The test equipment described in the present invention consists of four continuous error test units and a burst signal controller. The continuous error test units and the burst signal controller are connected by a cable. The four continuous error test units are independent and unrelated to each other, allowing them to operate independently. The burst signal controller's interface includes four independently controllable burst control signals (BEN), four independently collected LOS / SD signals, four independently controllable burst optical power collection control signals (Triger), and four independently controllable reset signals (Reset).

[0027] The BEN signal described in the present invention is generated by the main chip of the burst signal controller (usually an MCU or FPGA) and is used to control the ONU light source to emit light or turn it off.

[0028] The LOS / SD signal acquisition described in this invention is linked to the BEN signal. The burst signal controller's main chip collects the data and calculates the delay between the LOS / SD signal and the BEN signal, the number of LOS / SD signal pulses, and the delay between the SD signal and the Reset signal. These data are then provided to the host computer software to determine whether the LOS / SD signal meets requirements. This test is typically performed using an oscilloscope.

[0029] The Triger signal described in this invention is associated with the BEN signal. During the initial phase of the BEN signal controlling the ONU's light emission, the Triger signal is generated to trigger the OLT optical module to sample the burst optical power, further enabling burst optical power calibration. The Triger signal's delay and pulse width relative to the burst control signal are configurable.

[0030] The Reset signal described in the present invention is associated with the BEN signal. The Reset signal is generated when the BEN control signal is turned on and off to reset the receiving end of GPON / XGPON / XGSPON to ensure that the SD signal can be switched correctly.

[0031] The bit error test channel of the present invention can independently set different rates / code types, can work in parallel, and can test the bit error rate independently.

[0032] The test equipment of the present invention can support continuous bit error testing, can be used for debugging the APD voltage of the OLT optical module, debugging the LOS / SD signal, and calibrating the burst optical power, and realize all receiving end testing and debugging requirements of the OLT optical module.

[0033] This patent can solve the problems of low efficiency of traditional single-channel test equipment and inability to support multi-channel parallel testing; different PON protocols require hardware equipment replacement, resulting in high costs and poor flexibility. The multi-channel parallel error test unit can achieve 4-channel parallel testing to improve test efficiency, and the protocol adaptation module is compatible with GPON / XGPON / XGSPON, without the need to replace hardware, and the equipment multiplexing rate is increased by 100%. The provided multi-channel continuous error test module can realize testing with four independent and parallel error test units, greatly improving test efficiency.

[0034] The multi-channel continuous error code test module includes: Pattern generator unit, used to generate programmable PRBS test patterns; Clock and data recovery unit, used to extract clock and data from the receiving end signal of the OLT optical module; The error statistics unit calculates the bit error rate by comparing the transmitted pattern with the received data.

[0035] The above solution refines the multi-channel continuous error test module, and can implement testing of at least four independent error test units that can work in parallel at a time.

[0036] The burst signal control module includes: Four independent BEN signal output ports, used to control the on / off status of the ONU light source; Four-way LOS / SD signal acquisition ports for monitoring the loss of signal and signal detection status of optical modules; Four-way Triger signal output port, used to trigger burst optical power sampling; Four reset signal output ports, used to reset the optical module receiving end logic.

[0037] The above solution refines the burst signal control module into multiple signal output ports and the functions corresponding to each port.

[0038] The burst signal control module adopts a two-stage delay compensation mechanism, including: The first-level fixed delay compensation circuit is used to eliminate the transmission delay of the physical link; The second-level dynamically adjustable delay module dynamically corrects the synchronization deviation between the burst control signal and the trigger signal based on the correction formula; The correction formula is: , in, is the channel characteristic coefficient, is the reference offset, is the rising edge time of the BEN signal, is the measured Triger signal arrival time.

[0039] The above solution can solve the problem that traditional equipment uses fixed delay compensation and cannot eliminate dynamic deviations in signal transmission. The first-level delay compensation can eliminate physical link delays, and the second-level dynamic adjustment formula compensates for dynamic deviations. It can achieve precise compensation through quantized parameters (α, β) and adapt to different channel characteristics.

[0040] The calculation steps of the channel characteristic coefficient and the reference offset are: Inject a standard burst signal into the optical module to be tested and measure the actual response time of the Triger signal ; Target time according to the agreement , calculate the combination of the optimal channel characteristic coefficient and the reference offset according to the iterative formula; The iterative formula is: .

[0041] The above solution can solve the problem that manual calibration of burst timing parameters is inefficient and relies on operator experience. The above solution ensures the global optimal solution of compensation parameters α and β through mathematical optimization, ensuring that the calibration accuracy error is less than 0.1ns.

[0042] The error statistics unit adopts a double-window comparison algorithm: The first statistical window calculates the original bit error rate according to a fixed period ; The second statistical window dynamically adjusts the window length according to the valid data segment of the burst signal to calculate the effective bit error rate , and discard invalid data segments; The final bit error rate output is .

[0043] The above solution can solve the problem that the fixed statistical window cannot distinguish between valid and invalid data segments in the burst signal, resulting in excessively long low bit error rate testing time. This solution uses a dual-window comparison algorithm to effectively shorten the bit error rate statistics time by 60%.

[0044] The burst signal control module introduces random jitter interference into the reset signal and verifies the anti-interference capability of the optical module. The steps for verifying the anti-interference capability of the optical module are as follows: The reset signal falls on the edge of the superposition of the normal distribution The time jitter of It is an adjustable parameter of 1-50ns; Statistical bit error rate change ΔBER, if ΔBER>10 -3 The optical module is judged to be unqualified for anti-interference.

[0045] This solution can address the lack of quantitative testing standards for optical module anti-interference capabilities, which relies heavily on engineers' experience and judgment. The solution uses normally distributed random jitter interference to simulate real-world interference, improving anti-interference test coverage. The calculation of the statistical bit error rate change also clarifies the quantitative standard.

[0046] The multi-channel continuous error test module adopts a channel cross-validation mechanism: Channel A sends the standard PRBS pattern, and channel B receives it and calculates the bit error rate. Switch the channel roles and repeat the test. If the difference in the two bit error rates exceeds 10%, the hardware self-test procedure is triggered.

[0047] The above solution can solve the problem that single-channel testing cannot identify hardware errors; and the channel cross-validation mechanism can improve the hardware fault detection rate.

[0048] Unless otherwise specified, the device components involved in the above embodiments are all conventional device components, and the connection methods and control methods involved are all conventional connection methods and control methods unless otherwise specified.

[0049] The present invention has been described in detail above with reference to the embodiments. However, those skilled in the art will appreciate that, without departing from the spirit of the present invention, the specific parameters in the above embodiments may be modified to form multiple specific embodiments, which are all within the common variation range of the present invention and will not be described in detail here.

Claims

1. An OLT optical module receiving end test device, characterized in that: include: Multi-channel continuous error rate test module: Contains at least four independent error rate test units that can operate in parallel, used to generate high-speed test signals and analyze the bit error rate at the receiving end; Burst signal control module: connected to the multi-channel continuous error code test module, used to dynamically generate burst control signals, reset signals and trigger signals corresponding to each channel, and realize synchronous calibration of multi-channel error code test through timing control; The protocol adaptation module is embedded in the burst signal control module and automatically configures the burst period, optical power threshold, and reset timing according to the GPON / XGPON / XGSPON protocol.

2. The OLT optical module receiving end test device according to claim 1, characterized in that: The multi-channel continuous error code test module includes: Pattern generator unit, used to generate programmable PRBS test patterns; Clock and data recovery unit, used to extract clock and data from the receiving end signal of the OLT optical module; The error statistics unit calculates the bit error rate by comparing the transmitted pattern with the received data.

3. The OLT optical module receiving end test device according to claim 1, characterized in that: The burst signal control module includes: Four independent BEN signal output ports, used to control the on / off status of the ONU light source; Four-way LOS / SD signal acquisition ports for monitoring the loss of signal and signal detection status of optical modules; Four-way Triger signal output port, used to trigger burst optical power sampling; Four reset signal output ports, used to reset the optical module's receiving logic.

4. The OLT optical module receiving end test equipment according to claim 1, characterized in that: The burst signal control module adopts a two-stage delay compensation mechanism, including: The first-level fixed delay compensation circuit is used to eliminate the transmission delay of the physical link; The second-level dynamically adjustable delay module dynamically corrects the synchronization deviation between the burst control signal and the trigger signal based on the correction formula; The correction formula is: , in, is the channel characteristic coefficient, is the reference offset, is the rising edge time of the BEN signal, is the measured Triger signal arrival time.

5. The OLT optical module receiving end test equipment according to claim 4, characterized in that: The calculation steps of the channel characteristic coefficient and the reference offset are: Inject a standard burst signal into the optical module to be tested and measure the actual response time of the Triger signal ; Target time according to the agreement , calculate the combination of the optimal channel characteristic coefficient and the reference offset according to the iterative formula; The iterative formula is: .

6. The OLT optical module receiving end test equipment according to claim 2, characterized in that: The error statistics unit adopts a double-window comparison algorithm: The first statistical window calculates the original bit error rate according to a fixed period ; The second statistical window dynamically adjusts the window length according to the valid data segment of the burst signal to calculate the effective bit error rate , and discard invalid data segments; The final bit error rate output is .

7. The OLT optical module receiving end test equipment according to claim 1, characterized in that: The burst signal control module introduces random jitter interference into the reset signal and verifies the anti-interference capability of the optical module. The steps for verifying the anti-interference capability of the optical module are as follows: The reset signal falls on the edge of the superposition of the normal distribution The time jitter of It is an adjustable parameter of 1-50ns; Statistical bit error rate change ΔBER, if ΔBER>10 -3 The optical module is judged to be unqualified for anti-interference.

8. The OLT optical module receiving end test equipment according to claim 1, characterized in that: The multi-channel continuous error test module adopts a channel cross-validation mechanism: Channel A sends the standard PRBS pattern, and channel B receives it and calculates the bit error rate. Switch the channel roles and repeat the test. If the difference in the two bit error rates exceeds 10%, the hardware self-test procedure is triggered.

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