A high-speed direct-modulation and direct-detection passive optical network receiver control method and system

Abstract

This invention discloses a high-speed direct-modulation direct-detection passive optical network (SOA) receiver control method and system, relating to the field of optical access network technology. The high-speed direct-modulation direct-detection SOA receiver control method includes the following steps: amplifying the received optical signal and calculating the corresponding received power and bit error rate; using the received power and bit error rate as control parameters, performing closed-loop control to determine the optimal optical signal amplification amplitude. This invention enables the SOA output signal to be at the optimal received amplitude at the receiver, thereby increasing the receiver's power budget.

Description

Technical Field

[0001] This invention relates to the field of optical access network technology, specifically to a high-speed direct-modulation and direct-detection passive optical network receiver control method and system. Background Technology

[0002] To adapt to the rapid growth of emerging applications such as high-definition video streaming, online games, and cloud services, the transmission capacity of optical access networks needs to be significantly enhanced. In the past few years, the data rate per wavelength has been upgraded from approximately 1Gb / s to 10Gb / s and 25Gb / s.

[0003] Currently, several organizations are dedicated to promoting the development of high-speed passive optical network (PON) technology. IEEE 802.3ca has proposed researching next-generation 100Gb / s PONs. While coherent detection offers high receiver sensitivity and is an effective way to improve signal capacity, it requires expensive components and consumes significant power, making it unsuitable for cost-sensitive PON (Passive Optical Network) systems at the ONU (Optical Network Unit) end. Direct detection (DD) is often preferred for PON systems due to its cost-effectiveness and simple structure. To achieve a 1:64 splitting ratio over a 20km transmission distance, the power budget needs to meet the 29dB requirement of IEEE PR-30. However, fiber dispersion, nonlinearity, and bandwidth limitations are major problems in high-speed DD systems, resulting in lower receiver sensitivity. Simultaneously, the high input power at the transmitter introduces significant nonlinearity, limiting the transmit power and posing a challenge to achieving a high power budget for PON systems.

[0004] To improve the power budget of a high-speed direct-detection PON system, using a semiconductor optical amplifier at the receiver is an effective solution. Furthermore, since photodetectors (PDs) can be easily integrated with SOAs (semiconductor optical amplifiers), the additional cost to the system is relatively small. The amplification of an SOA is related to its input current; excessively large input current can cause SOA output saturation, leading to significant nonlinearity and ultimately reducing system performance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the first aspect of this invention provides a high-speed direct-modulation and direct-detection passive optical network receiver control method, which enables the SOA output signal to be at the optimal receiving amplitude of the receiver, thereby increasing the power budget of the receiver.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A high-speed direct-modulation and direct-detection passive optical network receiver control method, the method comprising the following steps:

[0008] Amplify the received optical signal and calculate the corresponding received power and bit error rate;

[0009] Closed-loop control is performed using received power and bit error rate as control parameters to determine the optimal optical signal amplification amplitude.

[0010] In some embodiments, the closed-loop control using received power and bit error rate as control parameters to determine the optimal optical signal amplification includes:

[0011] The received power is continuously adjusted in the same direction.

[0012] If the bit error rate continues to decrease, adjust the receiving power to the maximum adjustment range, or stop adjusting when the bit error rate decreases to the minimum value;

[0013] If the bit error rate increases, the receiving power is continuously adjusted in the opposite direction until the receiving power is adjusted to the maximum adjustment range or the bit error rate is reduced to the minimum value and then the adjustment is stopped.

[0014] The optimal optical signal amplification amplitude is determined by the amplification amplitude at which adjustment stops.

[0015] In some embodiments, the received optical signal is amplified by a semiconductor optical amplifier (SOA).

[0016] In some embodiments, the magnitude of the SOA input current is adjusted to regulate its amplification, thereby adjusting the received power.

[0017] In some embodiments, after amplifying the received optical signal and before calculating the corresponding received power and bit error rate, the method further includes:

[0018] The amplified optical signal undergoes photoelectric conversion and analog-to-digital conversion in sequence.

[0019] The second aspect of the present invention provides a high-speed direct-modulation and direct-detection passive optical network receiver control system, which enables the SOA output signal to be the optimal receiving amplitude of the receiver, thereby increasing the power budget of the receiver.

[0020] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0021] A high-speed direct-modulation and direct-detection passive optical network receiver control system includes:

[0022] An optical amplifier, used to amplify received optical signals;

[0023] The digital signal processing module is used to calculate the received power and bit error rate of the amplified optical signal;

[0024] The control module is used for closed-loop control with received power and bit error rate as control parameters, and for feedback adjustment of the amplification amplitude of the optical amplifier.

[0025] In some embodiments, the control module performs closed-loop control using received power and bit error rate as control parameters, and adjusts the amplification amplitude of the optical amplifier based on feedback, including:

[0026] The received power is continuously adjusted in the same direction.

[0027] If the bit error rate continues to decrease, adjust the receiving power to the maximum adjustment range, or stop adjusting when the bit error rate decreases to the minimum value;

[0028] If the bit error rate increases, the receiving power is continuously adjusted in the opposite direction until the receiving power is adjusted to the maximum adjustment range or the bit error rate is reduced to the minimum value, at which point the adjustment stops.

[0029] In some embodiments, the optical amplifier is a semiconductor optical amplifier (SOA).

[0030] In some embodiments, the control module includes:

[0031] The current control unit adjusts the amplification of the SOA by regulating the input current of the SOA, thereby adjusting the received power.

[0032] In some embodiments, it also includes:

[0033] A photodetector is used to convert amplified optical signals into photoelectric signals;

[0034] The analog-to-digital conversion module is used to convert the photoelectric signal into an analog-to-digital signal and output it to the digital signal processing module.

[0035] Compared with the prior art, the advantages of the present invention are as follows:

[0036] The high-speed direct-modulation direct-detection passive optical network (SOA) receiver control method of this invention amplifies the received optical signal and calculates the corresponding received power and bit error rate (BER). Using the received power and BER as control parameters, closed-loop control is performed to determine the optimal optical signal amplification amplitude. This ensures that the SOA output signal is at the optimal received amplitude at the receiver, thereby increasing the receiver's power budget. Attached Figure Description

[0037] Figure 1 This is a flowchart of the high-speed direct-modulation and direct-detection passive optical network receiver control method in an embodiment of the present invention;

[0038] Figure 2This is a flowchart of step S2 in an embodiment of the present invention;

[0039] Figure 3 This is a structural block diagram of the high-speed direct-modulation and direct-detection passive optical network receiver control system in an embodiment of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] See Figure 1 As shown in the figure, this invention discloses a high-speed direct-modulation and direct-detection passive optical network receiver control method, which includes the following steps:

[0042] S1. Amplify the received optical signal and calculate the corresponding received power and bit error rate.

[0043] In this embodiment, a semiconductor optical amplifier (SOA) is used to amplify the received optical signal. It is understood that other amplification methods can also be chosen, and this embodiment of the invention does not impose any limitations.

[0044] Furthermore, it is worth noting that in this embodiment, after the received optical signal is amplified, it enters the photodetector for photoelectric conversion, then undergoes analog-to-digital conversion, and is then sent to the digital signal processing module for clock synchronization, average power calculation, data recovery, bit error rate calculation (for handshake packets), and other processing steps.

[0045] S2. Closed-loop control is performed using received power and bit error rate as control parameters to determine the optimal optical signal amplification amplitude.

[0046] Specifically, step S2 includes:

[0047] S21. Continuously adjust the received power in the same direction.

[0048] It is understandable that continuous adjustment in the same direction refers to continuous adjustment in one direction, such as continuously increasing the received power or continuously decreasing the received power.

[0049] In this embodiment of the invention, the input current of the SOA is adjusted to adjust its amplification and thus the received power. Of course, other methods can also be adopted, and this embodiment of the invention does not limit them.

[0050] S22. If the bit error rate continues to decrease, adjust the receiving power to the maximum adjustment range, or stop adjusting when the bit error rate decreases to the minimum value.

[0051] If the bit error rate decreases, it indicates that the adjustment direction is correct. At this point, the adjustment will continue in the correct direction until the maximum adjustment range is reached, or the bit error rate is reduced to the minimum value.

[0052] S23. If the bit error rate increases, the receiving power is continuously adjusted in the reverse direction until the receiving power is adjusted to the maximum adjustment range or the bit error rate is reduced to the minimum value, at which point the adjustment stops.

[0053] If the bit error rate increases, it indicates that the adjustment direction is incorrect. In this case, it is necessary to adjust in the opposite direction. Generally speaking, the trend of the bit error rate can be changed after the reverse adjustment. Similarly, after the correct adjustment direction is determined, it will be maintained until the maximum adjustment range is reached or the bit error rate is reduced to the minimum value.

[0054] S24. The optimal optical signal amplification amplitude is determined by the amplification amplitude corresponding to the point where adjustment stops.

[0055] The following example will further illustrate the entire process:

[0056] The optical signal sent to the receiver is first amplified by the SOA (Optical Signal Amplifier), then converted to photoelectric signal by a photodetector, followed by analog-to-digital conversion. Finally, it is sent to the digital signal processing module for clock synchronization, average power calculation, data recovery, and bit error rate (BER) calculation (for handshake packets). The amplification amplitude of the SOA is controlled by a current control module. The output parameters of the current control module are controlled by the received power and BER results from the digital signal processing module. When the received data power is low, the SOA current amplitude is increased, thus increasing the received data power, while simultaneously monitoring the BER value until it reaches its minimum. When the received data power is too high, the SOA current amplitude is decreased, while still monitoring the BER value to minimize it. This ensures that the SOA output signal is at the optimal received amplitude for the receiver, thereby increasing the receiver's power budget.

[0057] The execution steps of this invention embodiment are as follows: First, during PON system initialization, the receiving end receives handshake data packets and sets the SOA current value. The setting process is as follows: After receiving the handshake data packets, the receiving end calculates the average power of the data packets in the digital signal processing module and records the BER value. When the average power is lower than the set standard average power, the current control module is notified to increase the SOA current to increase the amplification of the received signal. Simultaneously, the BER value continues to be monitored. If the BER value continues to decrease, the SOA current continues to increase. When the SOA current value increases to its maximum operating range or the BER value decreases to its minimum, the SOA reaches its optimal operating state, and the system reaches its optimal power budget (if the BER also increases while increasing the SOA current, it indicates that the SOA has reached saturation, causing nonlinear damage to the system). When the average power is higher than the set standard average power, the current control module is notified to decrease the SOA current to reduce the amplification of the received signal. Simultaneously, the BER value continues to be monitored. If the BER value continues to decrease, the SOA current continues to decrease. When the BER value decreases to its minimum, i.e., the BER increases due to the continued decrease in SOA current, the SOA also reaches its optimal operating state, and the system reaches its optimal power budget. Once the handshake packet is sent and the SOA parameters are set, the system begins to receive data normally.

[0058] In summary, the high-speed direct-modulation direct-detection passive optical network (SOA) receiver control method of this invention amplifies the received optical signal and calculates the corresponding received power and bit error rate (BER). Using the received power and BER as control parameters, closed-loop control is performed to determine the optimal optical signal amplification amplitude. This ensures that the SOA output signal is at the optimal received amplitude at the receiver, thereby increasing the receiver's power budget.

[0059] Meanwhile, see Figure 3 As shown in the figure, this embodiment of the invention also discloses a high-speed direct-modulation and direct-detection passive optical network receiver control system, including an optical amplifier, a digital signal processing module and a control module.

[0060] The optical amplifier is used to amplify the received optical signal; the digital signal processing module is used to calculate the received power and bit error rate of the amplified optical signal; and the control module is used to perform closed-loop control with the received power and bit error rate as control parameters, and to adjust the amplification amplitude of the optical amplifier based on feedback.

[0061] In some embodiments, the control module performs closed-loop control using received power and bit error rate as control parameters, and adjusts the amplification amplitude of the optical amplifier based on feedback, including:

[0062] The receiving power is continuously adjusted in the same direction. If the bit error rate continues to decrease, the receiving power is adjusted to the maximum adjustment range or the adjustment is stopped when the bit error rate is reduced to the minimum value. If the bit error rate increases, the receiving power is continuously adjusted in the opposite direction until the receiving power is adjusted to the maximum adjustment range or the adjustment is stopped when the bit error rate is reduced to the minimum value.

[0063] In some embodiments, the optical amplifier is a semiconductor optical amplifier (SOA).

[0064] In some embodiments, the control module includes:

[0065] The current control unit adjusts the amplification of the SOA by regulating the input current of the SOA, thereby adjusting the received power.

[0066] In some embodiments, the high-speed direct-modulation and direct-detection passive optical network receiver control system further includes:

[0067] A photodetector is used to convert amplified optical signals into photoelectric signals;

[0068] The analog-to-digital conversion module is used to convert the photoelectric signal into an analog-to-digital signal and output it to the digital signal processing module.

[0069] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A high-speed direct-modulation and direct-detection passive optical network receiver control method, characterized in that, The method includes the following steps: Amplify the received optical signal and calculate the corresponding received power and bit error rate; Closed-loop control is performed using received power and bit error rate as control parameters to determine the optimal optical signal amplification amplitude. The closed-loop control, using received power and bit error rate as control parameters, to determine the optimal optical signal amplification amplitude includes: The received power is continuously adjusted in the same direction. If the bit error rate continues to decrease, adjust the receiving power to the maximum adjustment range, or stop adjusting when the bit error rate decreases to the minimum value; If the bit error rate increases, the receiving power is continuously adjusted in the opposite direction until the receiving power is adjusted to the maximum adjustment range or the bit error rate is reduced to the minimum value and then the adjustment is stopped. The optimal optical signal amplification amplitude is determined by the amplification amplitude at which adjustment stops.

2. The high-speed direct-modulation and direct-detection passive optical network receiver control method according to claim 1, characterized in that: The received optical signal is amplified by a semiconductor optical amplifier (SOA).

3. The high-speed direct-modulation and direct-detection passive optical network receiver control method according to claim 2, characterized in that, The amplification of the SOA is adjusted by regulating the input current, thereby adjusting the received power.

4. The high-speed direct-modulation and direct-detection passive optical network receiver control method according to claim 1, characterized in that: After amplifying the received optical signal but before calculating the corresponding received power and bit error rate, the following steps are also included: The amplified optical signal undergoes photoelectric conversion and analog-to-digital conversion in sequence.

5. A high-speed direct-modulation and direct-detection passive optical network receiver control system, characterized in that, include: An optical amplifier, used to amplify received optical signals; The digital signal processing module is used to calculate the received power and bit error rate of the amplified optical signal; The control module is used for closed-loop control with received power and bit error rate as control parameters, and for feedback adjustment of the amplification amplitude of the optical amplifier. The control module performs closed-loop control using received power and bit error rate as control parameters, and provides feedback to adjust the amplification amplitude of the optical amplifier, including: The received power is continuously adjusted in the same direction. If the bit error rate continues to decrease, adjust the receiving power to the maximum adjustment range, or stop adjusting when the bit error rate decreases to the minimum value; If the bit error rate increases, the receiving power is continuously adjusted in the opposite direction until the receiving power is adjusted to the maximum adjustment range or the bit error rate is reduced to the minimum value, at which point the adjustment stops.

6. The high-speed direct-modulation and direct-detection passive optical network receiver control system according to claim 5, characterized in that: The optical amplifier is a semiconductor optical amplifier (SOA).

7. The high-speed direct-modulation and direct-detection passive optical network receiver control system according to claim 6, characterized in that, The control module includes: The current control unit adjusts the amplification of the SOA by regulating the input current of the SOA, thereby adjusting the received power.

8. The high-speed direct-modulation and direct-detection passive optical network receiver control system according to claim 5, characterized in that, Also includes: A photodetector is used to convert amplified optical signals into photoelectric signals; The analog-to-digital conversion module is used to convert the photoelectric signal into an analog-to-digital signal and output it to the digital signal processing module.

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