Optical network communication methods, systems, related devices and vehicles

Abstract

This application relates to an optical network communication method, system, related apparatus, and vehicle, and pertains to the field of coherent optical communication technology. The method is applied to the transmitting end of a first node in an optical network communication system. The method includes: modulating data to be transmitted into multiple subcarrier signals; filtering the multiple subcarrier signals using multiple filters to obtain multiple filtered subcarrier signals, wherein the amplitude and phase of the multiple filtered subcarrier signals are different; generating corresponding optical signals based on the multiple filtered subcarrier signals; and sending the optical signals to the receiving end of a second node in the optical network communication system. This method achieves efficient modulation and transmission of uplink signals through carrierless amplitude-phase modulation technology, while also helping to simplify the number of components in an optical network unit.

Description

Technical Field

[0001] This application relates to the field of coherent optical communication technology, and in particular to an optical network communication method, system, related device and vehicle. Background Technology

[0002] With the rapid development of intelligent vehicles and autonomous driving technologies, in-vehicle networks are placing higher demands on data transmission rates, reliability, and cost-effectiveness. While traditional modulation and demodulation technologies used in optical line terminals (OLTs) / optical network units (ONUs) of passive optical networks (PONs), such as orthogonal frequency division multiplexing (OFDM), meet the requirements for high-speed data transmission to some extent, they suffer from complex signal processing procedures and high hardware costs, thus limiting their development and application in in-vehicle environments. Summary of the Invention

[0003] This application provides an optical network communication method, system, related device, and vehicle to solve the problem that passive optical network communication systems in vehicles are complex and costly.

[0004] To achieve the above objectives, according to a first aspect of this application, an optical network communication method is provided, the method being applied to the transmitting end of a first node in an optical network communication system, the method comprising:

[0005] The data to be transmitted is modulated into multiple subcarrier signals;

[0006] The multiple subcarrier signals are filtered by multiple filters to obtain multiple filtered subcarrier signals, wherein the amplitude and phase of the multiple filtered subcarrier signals are different.

[0007] Based on the multiple filtered subcarrier signals, a corresponding optical signal is generated and the optical signal is sent to the receiving end of the second node in the optical network communication system.

[0008] Optionally, modulating the data to be transmitted into multiple subcarrier signals includes:

[0009] The data to be transmitted is processed by pulse amplitude modulation to obtain multiple subcarrier signals of the data to be transmitted.

[0010] Optionally, the subcarrier signal includes a first component signal and a second component signal.

[0011] Optionally, the step of filtering the multiple component signals using multiple filters to obtain multiple filtered subcarrier signals includes:

[0012] The first component signal is filtered based on the first filter to obtain the filtered first component signal;

[0013] The second component signal is filtered based on the second filter to obtain the filtered second component signal;

[0014] The filtered subcarrier signal is obtained based on the filtered first component signal and the filtered second component signal.

[0015] Optionally, if the data to be transmitted is uplink data, the first filter and the second filter are orthogonal to each other.

[0016] Optionally, when the data to be transmitted is downlink data, obtaining the filtered subcarrier signal based on the filtered first component signal and the filtered second component signal includes:

[0017] The filtered first component signal and the filtered second component signal are quadrature modulated respectively to obtain the modulated first component signal and the modulated second component signal;

[0018] The filtered subcarrier signal is obtained based on the modulated first component signal and the modulated second component signal.

[0019] Optionally, the step of performing quadrature modulation on the filtered first component signal and the filtered second component signal to obtain the modulated first component signal and the modulated second component signal includes:

[0020] The first reference signal is modulated based on the filtered first component signal to obtain the modulated first component signal;

[0021] The second reference signal is modulated based on the filtered second component signal to obtain the modulated second component signal, wherein the first reference signal and the second reference signal are orthogonal.

[0022] Optionally, generating the corresponding optical signal based on the plurality of filtered component signals includes:

[0023] The multiple filtered subcarrier signals are superimposed to obtain a bandpass pulse signal;

[0024] The optical signal is the optical signal corresponding to the bandpass pulse signal.

[0025] Optionally, modulating the data to be transmitted into multiple subcarrier signals includes:

[0026] The multiple data segments of the data to be transmitted are mapped respectively to obtain the real part and the imaginary part corresponding to each data segment;

[0027] The plurality of subcarrier signals are determined based on the real component and the imaginary component corresponding to each data segment.

[0028] Optionally, generating the corresponding optical signal based on the plurality of filtered subcarrier signals includes:

[0029] Based on preset time-division multiplexing rules, the transmission time period of the optical signal is determined;

[0030] A corresponding optical signal is generated during the transmission time period.

[0031] Optionally, generating the corresponding optical signal based on the plurality of filtered subcarrier signals includes:

[0032] The target code sequence is determined based on the preset code division multiplexing rules;

[0033] Based on the target code sequence, the multiple filtered subcarrier signals are spread to obtain the spread signal;

[0034] A corresponding optical signal is generated based on the spread spectrum signal.

[0035] Optionally, generating a corresponding optical signal based on the plurality of filtered subcarrier signals includes:

[0036] The target wavelength is determined based on the preset wavelength division multiplexing rules;

[0037] The optical signal of the target wavelength is generated based on the multiple filtered subcarrier signals.

[0038] Optionally, the step of filtering the multiple subcarrier signals using multiple filters to obtain multiple filtered subcarrier signals includes:

[0039] Filter the target signal and blank signal from multiple preset signals;

[0040] Different subcarrier signals are modulated onto the corresponding target signal to obtain the multiple filtered subcarrier signals.

[0041] Optionally, the method further includes:

[0042] The blank signal and the bandpass pulse signal corresponding to the data to be transmitted are combined;

[0043] An optical signal is generated and transmitted based on the synthesized signal.

[0044] According to a second aspect of this application, embodiments of this application also provide an optical network communication method, the method being applied to the receiving end of a second node in an optical network communication system, the method comprising:

[0045] Based on the optical signal received from the transmitter of the first node, the data to be demodulated is obtained;

[0046] The data to be demodulated is filtered by multiple matched filters to obtain multiple subcarriers to be demodulated;

[0047] The plurality of subcarriers to be demodulated are demodulated into data to be transmitted.

[0048] Optionally, the step of filtering the data to be demodulated using multiple matched filters to obtain multiple subcarriers to be demodulated includes:

[0049] The data to be demodulated is filtered using a third-wave filter to obtain the first component signal of the subcarrier to be demodulated.

[0050] The data to be demodulated is filtered using a fourth-wave filter to obtain the second component signal of the subcarrier to be demodulated.

[0051] The subcarrier to be demodulated is obtained based on the first component signal and the second component signal of the subcarrier to be demodulated.

[0052] Optionally, when the data to be transmitted is downlink data, the third filter and the fourth filter are orthogonal to each other.

[0053] Optionally, when the data to be transmitted is uplink data, the filtering of the data to be demodulated based on the third filter to obtain the first component signal of the subcarrier to be demodulated; and the filtering of the data to be demodulated based on the fourth filter to obtain the second component signal of the subcarrier to be demodulated, includes:

[0054] The data to be demodulated is quadrature demodulated to obtain the first demodulated signal and the second demodulated signal of the subcarrier to be demodulated;

[0055] The first demodulated signal is filtered by the third filter to obtain the first component signal of the subcarrier to be demodulated.

[0056] The second demodulated signal is filtered by the fourth filter to obtain the second component signal of the subcarrier to be demodulated.

[0057] Optionally, the step of performing orthogonal demodulation on the data to be demodulated to obtain the first demodulated signal and the second demodulated signal of the subcarrier to be demodulated includes:

[0058] Based on the first reference signal, the data to be demodulated is coherently demodulated to obtain the first demodulated signal of the subcarrier to be demodulated;

[0059] The data to be demodulated is coherently demodulated based on the second reference signal to obtain the second demodulated signal of the subcarrier to be demodulated, wherein the first reference signal and the second reference signal are orthogonal.

[0060] Optionally, demodulating the plurality of subcarriers to be demodulated into data to be transmitted includes:

[0061] The first component signal and the second component signal of each of the subcarriers to be demodulated are respectively used as the real part and the imaginary part of the data segment corresponding to the data to be transmitted;

[0062] The real and imaginary components of each data segment are mapped to obtain the data segment of the data to be transmitted, thereby determining the data to be transmitted.

[0063] Optionally, the method further includes:

[0064] Based on preset time-division multiplexing rules, the reception time period of the optical signal is determined;

[0065] During the receiving time period, the corresponding optical signal is received from the transmitter of the first node.

[0066] Optionally, the method further includes:

[0067] Based on preset code decomposition and multiplexing rules, the target code sequence corresponding to the transmitter of the first node is determined;

[0068] The digital signal corresponding to the optical signal is despread based on the target code sequence to obtain the despread signal, which is used as the data to be demodulated.

[0069] Optionally, the method further includes:

[0070] Based on the preset wave decomposition and multiplexing rules, the target wavelength corresponding to the transmitting end of the first node is determined;

[0071] The optical signal is separated to obtain the optical signal of the target wavelength.

[0072] Optionally, the method further includes:

[0073] Identify multiple target signals corresponding to the transmitter of the first node;

[0074] The demodulated data is demodulated based on each target signal to obtain the demodulated signal of the corresponding demodulated subcarrier.

[0075] According to a third aspect of this application, embodiments of this application also provide a transmitting end, the transmitting end comprising at least one digital-to-analog converter and at least one optical modulator, the at least one digital-to-analog converter and the at least one optical modulator being electrically connected; wherein,

[0076] The digital-to-analog converter is used to perform digital-to-analog conversion based on multiple filtered subcarriers to obtain the corresponding analog signal, and then send it to the optical modulator;

[0077] The optical modulator is used to modulate the optical carrier based on the analog signal and output an optical signal corresponding to the data to be transmitted.

[0078] Optionally, the number of digital-to-analog converters is one.

[0079] Optionally, the optical modulator is a Mach-Zehnder modulator.

[0080] Optionally, the bias voltage of the phase of one arm of the Mach-Zehnder modulator is zero, and the phase of the other arm is controlled by the analog signal corresponding to the plurality of filtered subcarrier signals.

[0081] According to a fourth aspect of this application, embodiments of this application also provide a receiving end, the receiving end comprising at least one photodetector and at least one analog-to-digital converter, the at least one photodetector and the at least one analog-to-digital converter being electrically connected; wherein,

[0082] The photodetector is used to perform photoelectric conversion on the optical signal corresponding to the data to be transmitted, to obtain the electrical signal corresponding to the data to be transmitted, and send it to the analog-to-digital converter;

[0083] The analog-to-digital converter is used to perform analog-to-digital conversion based on the electrical signal corresponding to the data to be transmitted, to obtain the data to be demodulated, so as to determine the data to be transmitted.

[0084] Optionally, the number of photodetectors is one, and the number of analog-to-digital converters is one.

[0085] Optionally, the receiver may further include a local oscillator for generating the target signal.

[0086] Optionally, the receiving end further includes a phase rotator, which is used to cause a phase shift in the target signal to obtain a first reference signal and a second reference signal.

[0087] Optionally, the system includes at least one node, which includes any of the transmitters and receivers provided in the embodiments of this application.

[0088] Optionally, the at least one node is an optical network unit or an optical line terminal, and at least one of the optical network units and the optical line terminal are connected via an optical fiber medium.

[0089] Optionally,

[0090] The transmitter of the optical network unit is connected to the receiver of the optical line terminal via an optical fiber medium.

[0091] The receiver of the optical network unit is connected to the transmitter of the optical line terminal via an optical fiber medium.

[0092] According to a fifth aspect of this application, embodiments of this application also provide a computer-readable storage medium having a computer program stored thereon, the computer-readable storage medium storing instructions that, when executed by a computer, cause the computer to implement any of the optical network communication methods provided in the embodiments of this application.

[0093] According to a sixth aspect of this application, embodiments of this application also provide a computer program product storing instructions that, when executed by a computer, cause the computer to implement any of the optical network communication methods described in the embodiments of this application.

[0094] According to a seventh aspect of this application, embodiments of this application also provide an electronic device, comprising:

[0095] A memory on which computer programs are stored;

[0096] A processor is configured to execute the computer program in the memory to implement any of the optical network communication methods provided in the embodiments of this application.

[0097] According to the eighth aspect of this application, embodiments of this application also provide a vehicle, including any of the optical network communication systems provided in embodiments of this application, or the electronic devices described herein, or performing any of the optical network communication methods provided in embodiments of this application.

[0098] Some embodiments of this specification include at least the following beneficial effects: at the transmitting end of the ONU, by performing carrier-free amplitude and phase modulation on the data to be transmitted, it is converted into amplitude and phase information, and a corresponding modulated signal is generated. This eliminates the need for a carrier signal, thereby simplifying the signal modulation process, helping to reduce the complexity of the ONU structure, and thus facilitating its deployment in an in-vehicle environment.

[0099] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0100] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0101] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0102] Figure 1 This is a schematic diagram of the structure of an optical network communication system according to some embodiments of this specification;

[0103] Figure 2 This is an exemplary flowchart of an optical network communication method according to some embodiments of this specification;

[0104] Figure 3 This is an exemplary flowchart of demodulated data according to some embodiments of this specification;

[0105] Figure 4 These are exemplary schematic diagrams of modulation and demodulation in an optical network unit according to some embodiments of this specification;

[0106] Figure 5 This is an exemplary schematic diagram of modulation and demodulation in an optical line terminal according to some embodiments of this specification;

[0107] Figure 6 These are exemplary schematic diagrams illustrating time-frequency resource transmission according to some embodiments of this specification;

[0108] Figure 7 These are exemplary schematic diagrams of uplink and downlink transmission spectrum according to some embodiments of this specification;

[0109] Figure 8 This is an exemplary schematic diagram of a transmitter according to some embodiments of this specification;

[0110] Figure 9 This is an exemplary schematic diagram of a receiver according to some embodiments of this specification;

[0111] Figure 10 This is a schematic diagram of the structure of an electronic device according to some embodiments of this specification. Detailed Implementation

[0112] 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0113] To facilitate understanding of the implementation schemes provided in this application, the relevant application background of the optical network communication system provided in this application will be explained first.

[0114] With the development of intelligent vehicles and autonomous driving technologies, vehicular networks are placing higher demands on data transmission rates, reliability, and cost-effectiveness. Coherent Passive Optical Networks (PONs) are passive optical networks utilizing coherent detection technology. They consist of an Optical Line Terminal (OLT) and an Optical Network Unit (ONU). By using in-vehicle coherent optical network communication technology, higher data transmission rates and longer transmission distances can be achieved. However, traditional PON systems are struggling to meet future demands in terms of bandwidth capacity, signal processing complexity, and ease of maintenance. The high cost and complexity of coherent PON systems limit their application in automotive environments.

[0115] In related technologies, there is a wavelength division multiplexing coherent passive optical network system. This system does not optimize the coherent receiver structure, and its receiver requires four analog-to-digital converters and four balanced photodetectors, resulting in high costs.

[0116] An ONU and its signal receiving method for a coherent PON system based on a directly modulated laser are disclosed. This scheme uses a directly modulated laser to achieve coherent reception, but still requires four analog-to-digital converters to recover four signals. Although it uses a directly modulated laser, it does not significantly reduce the system complexity and cost.

[0117] A system and method for coherent optical backhaul is provided, which integrates coherent and direct modulation receivers. However, this approach is not suitable for automotive electrical and electronic architectures because the automotive environment has special requirements for cost, reliability, and maintainability.

[0118] A wavelength division multiplexing passive optical network system with single-sideband carrierless amplitude-phase modulation (CAP) is proposed. This scheme designs a direct modulation and direct detection PON system using single-sideband carrierless amplitude-phase modulation (CAP). However, this scheme includes Nyquist filtering, Hilbert transform and other steps, which increases the complexity of the system.

[0119] In view of this, some embodiments of this specification provide an optical network communication method and system that simplifies the design of the ONU, eliminating the need for multiple sets of digital-to-analog converters (DACs), Mach-Zehnder modulators (MZMs), balanced photodetectors (BPDs), and analog-to-digital converters (ADCs) required in traditional PON systems. The converter (ADC) components are integrated into a single unit, reducing hardware costs and power consumption. CAP modulation technology is used to compensate for potential signal distortion caused by hardware simplification, maintaining high-performance signal processing capabilities. Through a simplified ONU, combined with carrier-free amplitude-phase modulation (CAP) technology, efficient uplink signal modulation and transmission are achieved. The use of carrier-free amplitude-phase modulation for uplink signals, combined with coherent demodulation of downlink signals, optimizes the modulation and demodulation process, reduces signal processing complexity, and improves signal transmission efficiency. A coherent PON system built on this simplified ONU can achieve data transmission rates exceeding 100Gbps, significantly increasing the bandwidth capacity of the vehicle-mounted PON system and meeting future high-speed data transmission requirements. Traditional coherent ONUs typically contain multiple DAC, MZM, BPD, and ADC components; by simplifying these components into a single unit, the architecture deployment cost is significantly reduced while maintaining high-performance signal processing capabilities. Furthermore, the simplified ONU design reduces the number of components, lowers the failure rate, and improves system reliability and ease of maintenance.

[0120] Figure 1 This is a schematic diagram of the structure of an optical network communication system according to some embodiments of this specification.

[0121] like Figure 1 As shown, the optical network communication system 100 may include at least one node.

[0122] A node refers to a physical or logical entity in an optical network communication system. Nodes are interconnected through optical fiber media and are responsible for sending, receiving, and processing optical signals.

[0123] In some embodiments, the node may be a domain controller in the vehicle (such as a body domain, cockpit domain, driving domain, etc.), the vehicle control unit (VCU), etc.

[0124] In some embodiments, a node includes a transmitter and a receiver.

[0125] In some embodiments, at least one node includes at least one optical network unit and an optical line terminal, and the at least one optical network unit and the optical line terminal are connected via an optical fiber medium.

[0126] In some embodiments, the transmitter of the optical network unit is connected to the receiver of the optical line terminal via an optical fiber medium; the receiver of the optical network unit is connected to the transmitter of the optical line terminal via an optical fiber medium.

[0127] Figure 8 This is an exemplary schematic diagram of a transmitter according to some embodiments of this specification.

[0128] In some embodiments, such as Figure 8 As shown, the nodes of the optical network communication system 100 include a transmitter, which includes at least one digital-to-analog converter and at least one optical modulator, and the digital-to-analog converter and the optical modulator are electrically connected.

[0129] The transmitter is used to convert electrical signals into optical signals and send them out through the optical fiber medium.

[0130] A digital-to-analog converter (DAC) is an electronic device used to convert digital signals into analog signals. For example, a DAC can convert discrete digital values ​​into continuous analog voltages or currents.

[0131] Optical modulators are used to modulate continuous light emitted by a laser to carry data information. For example, an optical modulator can change the characteristics of an optical signal (such as intensity, phase, frequency, or polarization) based on an electrical signal to transmit information corresponding to the electrical signal.

[0132] In some embodiments, the number of digital-to-analog converters is 1.

[0133] In some embodiments, the optical modulator is a Mach-Zehnder modulator (MZM). A Mach-Zehnder modulator can modulate an optical signal by changing the phase difference of light in two paths to achieve amplitude and phase modulation.

[0134] In some embodiments, the Mach-Zehnder modulator consists of two arms, each containing an electro-optic modulator. By loading an analog signal onto one arm of the Mach-Zehnder modulator, and changing the voltage of the electro-optic modulator to change the optical carrier from the laser in the electro-optic modulator, the phase difference of the light in the two arms is changed; the optical signals from the two arms interfere at the output to form a modulated optical signal.

[0135] In some embodiments, the bias voltage of the phase of one arm of the Mach-Zehnder modulator is zero, while the phase of the other arm is controlled by analog signals corresponding to multiple filtered subcarrier signals.

[0136] In some embodiments, the digital-to-analog converter is used to perform digital-to-analog conversion based on multiple filtered subcarrier signals to obtain a corresponding analog signal, which is then sent to the optical modulator; the optical modulator is used to modulate the optical carrier based on the analog signal and output an optical signal corresponding to the data to be transmitted.

[0137] Figure 9 This is an exemplary schematic diagram of a receiver according to some embodiments of this specification.

[0138] In some embodiments, such as Figure 9 As shown, the nodes of the optical network communication system 100 include a receiver, which includes at least one photodetector and at least one analog-to-digital converter, and the photodetector and the analog-to-digital converter are electrically connected.

[0139] The receiver is used to convert the received optical signals into electrical signals for subsequent processing.

[0140] A photodetector is a device that converts optical signals into electrical signals.

[0141] In some embodiments, the photodetector is a balanced photodetector (BPD). The photodetector consists of two photodiodes and can convert optical signals into electrical signals using differential detection technology.

[0142] An analog-to-digital converter (ADC) is an electronic device used to convert analog signals into digital signals. For example, an ADC can convert continuous analog voltage or current into discrete digital values.

[0143] In some embodiments, the photodetector is used to perform photoelectric conversion on the optical signal corresponding to the data to be transmitted, to obtain the electrical signal corresponding to the data to be transmitted, and send it to the analog-to-digital converter; the analog-to-digital converter is used to perform analog-to-digital conversion based on the electrical signal corresponding to the data to be transmitted, to obtain the data to be demodulated, so as to determine the data to be transmitted.

[0144] In some embodiments, the number of photodetectors is 1, and the number of analog-to-digital converters is 1.

[0145] In some embodiments, the nodes of an optical network communication system are optical network units.

[0146] The simplified ONU design reduces the number of components, which helps to lower the failure rate and improve system reliability and ease of maintenance.

[0147] In some embodiments, the nodes of the optical network communication system are optical line terminals.

[0148] In some embodiments, the receiver of the optical line terminal further includes a local oscillator for generating the target signal.

[0149] A local oscillator (LO) is used to generate a stable high-frequency oscillation signal (such as a target signal).

[0150] In some embodiments, the receiver of the optical line terminal further includes a phase rotator, which is used to cause a phase shift in the target signal to obtain a first reference signal and a second reference signal. The phase rotator can adjust the phase of the signal without changing the signal amplitude.

[0151] In some embodiments, the optical network unit and the optical line terminal are physically connected via single-mode or multimode optical fiber.

[0152] In some embodiments, one or more passive optical splitters (also called splitters) are deployed between the optical network unit and the optical line terminal. The passive optical splitter can split an optical signal emitted from the optical line terminal into multiple signals, which are then sent to different optical network units; at the same time, it can also combine signals from multiple optical network units into a single signal and send it to the optical line terminal.

[0153] In some embodiments, the optical line terminal may be integrated or installed in the vehicle central processing unit (VCU), and the optical network unit may be integrated or installed in various domain controllers of the vehicle (such as the body domain, cockpit domain, driver domain, etc.).

[0154] It should be noted that the above description of the optical network communication system 100 and its components is for convenience only and should not be construed as limiting this specification to the scope of the illustrated embodiments. It is understood that those skilled in the art, after understanding the principles of the system, may arbitrarily combine the various modules or construct subsystems connected to other modules without departing from these principles. In some embodiments, Figure 1The components disclosed herein can be different modules within a system, or a single module can implement the functions of two or more modules described above. For example, modules can share a single storage module, or each module can have its own separate storage module. Such variations are all within the scope of this specification.

[0155] Figure 2 This is an exemplary flowchart of an optical network communication method according to some embodiments of this specification. In some embodiments, process 200 may be executed from the transmitting end of a first node in the optical network communication system. Figure 2 As shown, process 200 includes the following steps.

[0156] Step S210: Modulate the data to be transmitted into multiple subcarrier signals.

[0157] The data to be transmitted is the raw digital data stream. For example, the data to be transmitted could be sensor data, status information, and control commands sent by various domain controllers in the vehicle (such as the body domain, cockpit domain, driver domain, etc.) to the vehicle's central processing unit (VCU). Alternatively, the VCU receives data from various domain controllers and makes centralized decisions and controls based on this data. The VCU not only processes input information from each domain but also sends control commands, status updates, and other relevant information back to the respective domain controllers and other devices as data to be transmitted.

[0158] For example, the data to be transmitted may include, but is not limited to, door status, air conditioning system status, and sensor data of the interior and exterior environment in the vehicle body domain; the data to be transmitted may also include, but is not limited to, driver information, navigation system data, and voice assistant commands in the cockpit domain; and the data to be transmitted may also include, but is not limited to, vehicle dynamic data, engine status, braking system status data, and camera data in the driving domain.

[0159] For example, the data to be transmitted may include, but is not limited to, door control commands and window control commands sent to the body domain; the data to be transmitted may include, but is not limited to, navigation system commands and entertainment system control commands sent to the cockpit domain; the data to be transmitted may include, but is not limited to, engine control commands and braking system control commands sent to the driving domain.

[0160] Subcarrier signals refer to the result of modulating or mapping independent sub-signals extracted from the data to be transmitted. Each subcarrier signal carries a portion of the data information.

[0161] In some embodiments, the data to be transmitted can be converted from serial to parallel to obtain multiple data segments, and each data segment can be modulated into different symbols to obtain multiple subcarrier signals.

[0162] In some embodiments, modulating the data to be transmitted into multiple subcarrier signals includes: processing the data to be transmitted by pulse amplitude modulation to obtain multiple subcarrier signals of the data to be transmitted.

[0163] In some embodiments, the data to be transmitted is divided into a data segment according to a preset number of bits, and each data segment is pulse amplitude modulated to obtain a corresponding subcarrier signal.

[0164] The preset number of bits is related to the order of the pulse amplitude modulation (PAM). Different orders correspond to different amplitude levels. For example, if the PAM order is 4, the preset number of bits is 2. Or, if the PAM order is 8, the preset number of bits is 3.

[0165] In some embodiments, pulse amplitude modulation of different orders can be used depending on the service type.

[0166] In some embodiments, the optical network unit can determine modulation parameters or receive modulation parameters sent by the optical new path terminal according to the network design requirements and performance requirements. The modulation parameters include, but are not limited to, baud rate, modulation order (e.g., 4th order, 8th order, etc.), modulation type, etc. Based on the modulation parameters, the data to be transmitted is modulated to obtain a first modulation signal.

[0167] Baud rate refers to the number of symbols (or modulation symbols) transmitted per second. Each symbol can carry a preset number of information bits, which depends on the modulation order. For example, in Binary Phase Shift Keying (BPSK), each symbol carries 1 bit of information; in Quadrature Phase Shift Keying (QPSK), each symbol carries 2 bits of information; and in Quadrature Amplitude Modulation (QAM), each symbol carries 4 bits of information.

[0168] In some embodiments, each subcarrier signal consists of two PAM (Pulse Amplitude Modulation) signals. During the transmission of uplink data from the optical network unit to the optical line terminal (OLT), the subcarrier signal is a segment of data to be transmitted encoded using CAP (Capacitive Modulation). During the transmission of downlink data from the OLT to the optical network unit, the subcarrier signal is a segment of data to be transmitted encoded using QAM (Quick Amplitude Modulation). QAM modulation or CAP modulation includes modulation of different orders; for example, QAM modulation includes 4QAM, 16QAM, 64QAM, ..., 4QAM. 4QAM can also be called QPSK.

[0169] In some embodiments, the higher the order of QAM, the higher the signal transmission rate. It can be selected according to the service type. High-order QAM, such as 16QAM or 64QAM, can be used for high-speed and high-bandwidth audio and video signals, while QPSK can be used for low-speed and low-bandwidth automotive control signals.

[0170] In some embodiments, the optical line terminal can determine the modulation parameters of the carrierless amplitude and phase modulation method according to the network design requirements and performance requirements, and send them to the optical network unit.

[0171] In some embodiments, in PAM modulation, the amplitude and phase of each data segment are converted into a pulse signal, and the amplitude of the pulse signal is different to represent different information. The duration of each pulse signal is the modulation symbol period time.

[0172] For example, the data to be transmitted is an 8-bit binary sequence: 10011100. The data to be transmitted is divided into two data segments, each of which includes 4 bits. The amplitude and phase of each data segment are mapped to specific amplitude levels to obtain the corresponding two PAM signals.

[0173] In some embodiments of this specification, carrierless amplitude-phase modulation (CAP) technology is implemented using PAM signals, which helps to efficiently modulate and transmit uplink signals.

[0174] In some embodiments, modulating the data to be transmitted into multiple subcarrier signals includes: mapping multiple data segments of the data to be transmitted to obtain the real and imaginary components corresponding to each data segment; and determining multiple subcarrier signals based on the real and imaginary components corresponding to each data segment.

[0175] Furthermore, to achieve flexible bus rate adaptation from 100 Gbit / s to 200 Gbit / s, probabilistic constellation shaping technology using high-order QAM can be employed. This involves adjusting the signal modulation scheme according to different transmission requirements, thereby optimizing transmission efficiency. Simultaneously, before modulating the data to be transmitted, Alamouti encoding can be applied to obtain the encoded data. This allows for a system capacity comparable to a dual-polarization system based on single-polarization detection, not only improving signal transmission efficiency but also simplifying the receiver's hardware design, making the entire communication system more efficient and economical.

[0176] In some embodiments, each data segment in the data to be transmitted can be mapped to a different modulation symbol based on appropriate modulation parameters (such as 16QAM, 64QAM, etc.). Each modulation symbol may carry multiple bits of information simultaneously.

[0177] In some embodiments, the data to be transmitted can be divided into multiple data segments according to the requirements of the modulation scheme. For example, in 16QAM, every 4 bits constitute a data segment; based on the constellation diagram, the data segments are mapped to obtain a corresponding modulation symbol.

[0178] A constellation diagram is a two-dimensional graphic used to represent the position of modulation symbols in the complex plane. Each point on the constellation diagram represents a specific modulation symbol. A modulation symbol consists of amplitude and phase, used to carry data information. In the constellation diagram, each possible binary combination corresponds to a specific constellation point. For example, in 16QAM, there are 16 points on the constellation diagram, each point corresponding to 4 bits of data.

[0179] Mapping refers to the process of mapping a data segment to a specific point (i.e., a modulation symbol) on a constellation diagram. The mapping process converts a digital signal into a complex value that can be modulated.

[0180] In some embodiments, each modulation symbol consists of a real component and an imaginary component.

[0181] In some embodiments of this specification, probabilistic constellation shaping technology with QAM of different orders is used, which can adjust the modulation method of the signal according to different transmission requirements, thereby optimizing the transmission efficiency.

[0182] In some embodiments, the subcarrier signal includes a first component signal and a second component signal.

[0183] In some embodiments, the first component signal may be a signal component that is in phase with the reference carrier. For example, the first component signal is an in-phase component.

[0184] In some embodiments, the second component signal may be a signal component with a 90-degree phase offset relative to the reference carrier. For example, the second component signal may be an orthogonal component.

[0185] Step S220: Multiple subcarrier signals are filtered by multiple filters to obtain multiple filtered subcarrier signals, wherein the amplitude and phase of the multiple filtered subcarrier signals are different.

[0186] A filter is a device used to process different subcarrier signals of data to be transmitted. Filters can be used to alter the shape and frequency of subcarrier signals to ensure they meet specific spectral requirements. For example, filters can include root-raised cosine (RRC) filters and Gaussian filters.

[0187] In some embodiments, multiple subcarrier signals are filtered by multiple filters to obtain multiple filtered subcarrier signals, including: filtering a first component signal based on a first filter to obtain a filtered first component signal; filtering a second component signal based on a second filter to obtain a filtered second component signal; and obtaining a filtered subcarrier signal based on the filtered first component signal and the filtered second component signal.

[0188] The first filter is used to process the first component signal.

[0189] The second filter is a rectifier used to process the second component signal.

[0190] The first component signal after filtering refers to the first component signal after being processed by the first filter.

[0191] The filtered second component signal refers to the second component signal after being processed by the second filter.

[0192] In some embodiments, the filtered first component signal and the second component signal are combined to form a filtered subcarrier signal.

[0193] In some embodiments of this specification, filtering the two component signals can effectively reduce interference, improve spectral efficiency, and simplify signal processing at the receiver.

[0194] In some embodiments, when the data to be transmitted is uplink data, the first filter and the second filter are orthogonal to each other.

[0195] Uplink data refers to data sent from an optical network unit to an optical line terminal.

[0196] In some embodiments, when the data to be transmitted is uplink data, the first node is an optical network unit and the second node is an optical line terminal.

[0197] In some embodiments, the first filter can be obtained by multiplying a shaped filter by a cosine function, and the second filter can be obtained by multiplying a shaped filter by a sinine function. The shaped filter can include root-raised cosine filters and Gaussian filters, etc.

[0198] In some embodiments, different data segments can modulate signals at different carrier frequencies, resulting in different frequency bands for the modulated subcarrier signals. Each frequency band is isolated by a certain spectral interval, and each frequency band contains two filters.

[0199] The carrier frequency refers to the center frequency of the reference signal used to modulate the data. The frequency band refers to the range of frequencies occupied by the reference signal.

[0200] In some embodiments, the optical network unit can map multiple data segments in the data to be transmitted to obtain the real component and the imaginary component of each data segment; filter the real component signal based on the real component signal of each data segment using a first filter in the corresponding frequency band to obtain a filtered first component signal; filter the imaginary component signal based on a second filter in the corresponding frequency band to obtain a filtered second component signal; and obtain a filtered subcarrier signal based on the filtered first component signal and the filtered second component signal, wherein the first filter and the second filter are orthogonal to each other.

[0201] In some embodiments, multiple subcarrier signals of the data to be transmitted can be obtained in the manner described above.

[0202] In some embodiments, in an uplink communication system, each optical network unit (ONU) is responsible for transmitting a carrierless amplitude and phase modulated (CAP) signal. To achieve precise signal modulation, a Mach-Zehnder modulator (MZM) is biased to zero, ensuring the signal has steep rise and fall edges, thereby improving transmission efficiency. Burst patterns of the signal are generated by controlling the switching of the digital-to-analog converter (DAC). This control method allows for precise control of signal transmission timing to adapt to different communication requirements. To reduce DC leakage of laser power when the DAC is off, a guard band is specifically included in the system design. This design effectively suppresses unwanted signal interference, ensuring signal purity and transmission quality.

[0203] In some embodiments of this specification, CAP modulation is implemented in the ONU using two mutually orthogonal filters, which can filter out interference between signals, reducing computational complexity and system structure.

[0204] In some embodiments, when the data to be transmitted is downlink data, the filtered first component signal and the filtered second component signal are quadrature modulated to obtain the modulated first component signal and the modulated second component signal; based on the modulated first component signal and the modulated second component signal, the filtered subcarrier signal is obtained.

[0205] Downlink data refers to the data to be transmitted from the optical line terminal to the optical network unit.

[0206] In some embodiments, when the data to be transmitted is downlink data, the first node is an optical line terminal and the second node is an optical network unit.

[0207] In some embodiments, the target signal can be modulated based on the filtered first component signal and the filtered second component signal to obtain the modulated first component signal and the modulated second component signal.

[0208] A target signal refers to a high-energy or high-frequency signal that possesses characteristics such as amplitude, frequency, and phase, but does not contain any useful information. The frequency of the target signal is the center frequency within the corresponding frequency band.

[0209] In some embodiments, the target signal may include two or more mutually orthogonal carrier signals (e.g., quadrature carriers, in-phase carriers, etc.).

[0210] Quadrature modulation is the process of simultaneously modulating multiple filtered component signals.

[0211] In some embodiments, different target signals can be modulated based on multiple filtered subcarrier signals to obtain modulated subcarrier signals, thereby generating corresponding optical signals.

[0212] In some embodiments, orthogonal modulation is performed on the filtered first component signal and the filtered second component signal to obtain the modulated first component signal and the modulated second component signal, including: modulating a first reference signal based on the filtered first component signal to obtain the modulated first component signal; and modulating a second reference signal based on the filtered second component signal to obtain the modulated second component signal, wherein the first reference signal and the second reference signal are orthogonal.

[0213] The first reference signal and the second reference signal are the quadrature carrier and in-phase carrier corresponding to the target signal, respectively.

[0214] In some embodiments, the modulated first component signal is obtained based on the product of the first reference signal and the filtered first component signal; the modulated second component signal is obtained based on the product of the second reference signal and the filtered second component signal.

[0215] In some embodiments, the optical line terminal can map multiple data segments of the data to be transmitted to obtain the real and imaginary components corresponding to each data segment; use the real and imaginary components corresponding to each data segment as the first and second component signals corresponding to each data segment; filter the first component signal based on a first filter within the corresponding frequency band to obtain the filtered first component signal; filter the second component signal based on a second filter within the corresponding frequency band to obtain the filtered second component signal; obtain the modulated first component signal based on the product of the first reference signal and the filtered first component signal; and obtain the modulated second component signal based on the product of the second reference signal and the filtered second component signal.

[0216] In some embodiments, the filtered first component signal can be updated based on the modulated first component signal, and the filtered second component signal can be updated based on the modulated second component signal.

[0217] In some embodiments of this specification, QAM modulation is achieved through filtering and quadrature modulation, which can make fuller use of the bandwidth and has better noise immunity.

[0218] Step S230: Generate a corresponding optical signal based on multiple filtered subcarrier signals, and send the optical signal to the receiving end of the second node in the optical network communication system.

[0219] In some embodiments, multiple filtered subcarrier signals can be combined to obtain a combined signal, which is then converted into an analog signal by a digital-to-analog converter (DAC). The analog signal is then loaded onto an optical carrier by an optical modulator to generate an optical signal suitable for transmission over optical fiber. For example, the optical modulator can change the intensity, phase, or polarization state of the optical carrier according to the input analog signal.

[0220] In some embodiments, the transmitter of the optical network unit can send the optical signal corresponding to the data to be transmitted to the receiver of the optical line terminal via an optical fiber, or the transmitter of the optical line terminal can send the optical signal corresponding to the data to be transmitted to the receiver of the optical network unit via an optical fiber.

[0221] In some embodiments, multiple filtered subcarrier signals can be superimposed to obtain a bandpass pulse signal; the optical signal is the optical signal corresponding to the bandpass pulse signal.

[0222] In some embodiments, the two filtered component signals corresponding to a certain data segment can be superimposed to obtain the superimposed signal of the data segment. The superimposed signals of all data segments of the data to be transmitted are then synthesized to obtain a bandpass pulse signal.

[0223] Figure 4 This is an exemplary schematic diagram of modulation and demodulation in an optical network unit according to some embodiments of this specification.

[0224] In some embodiments, such as Figure 4 As shown, the optical network unit divides each data segment of the data to be transmitted into two paths and maps them into PAM signals. The two PAM signals are then passed through two mutually orthogonal shaping filters to obtain the filtered subcarrier signals of the data segment. Based on the multiple filtered subcarrier signals, an optical signal is generated and transmitted.

[0225] In some embodiments, such as Figure 4As shown, the bit stream of data to be transmitted can be modulated into subcarrier signals with multiple symbol periods. Each subcarrier signal is divided into two data paths. Pulse amplitude modulation is performed on the two data paths based on the subcarrier to obtain the first component signal and the second component signal. The first component signal and the second component signal are respectively passed through two mutually orthogonal shaping filters. The filtered first component signal and the filtered second component signal corresponding to each subcarrier are combined to generate a bandpass pulse signal s(t), as shown in formula (1):

[0226]

[0227] Where, ω kc =2πf kc A k,i B k,i Let f represent the component signal passing through the shaping filter in the k-th frequency band during the i-th symbol period. g(t-iT) is the response function of the shaping filter. T is the symbol period. kc It is the center frequency of the kth subcarrier.

[0228] In some embodiments, generating a corresponding optical signal based on multiple filtered subcarrier signals includes: determining the transmission time period of the optical signal based on a preset time-division multiplexing rule; and generating the corresponding optical signal during the transmission time period.

[0229] Time Division Multiplexing (TDM) is a data multiplexing method that divides time into fixed-length time slots and then allocates a specific time slot to each node to send data.

[0230] In some embodiments, the transmission time period is pre-allocated to each optical network unit by the optical line terminal, and each optical network unit can transmit optical signals in its respective transmission time period in chronological order, thereby avoiding signal conflicts between different optical network units.

[0231] In some embodiments, the optical network unit can activate the laser and transmit the corresponding optical signal during the transmission time slot, while remaining silent during other time slots.

[0232] In some embodiments, generating a corresponding optical signal based on multiple filtered subcarrier signals includes: determining a target code sequence based on a preset code division multiplexing rule; spreading multiple filtered subcarrier signals based on the target code sequence to obtain a spread signal; and generating a corresponding optical signal based on the spread signal.

[0233] Code Division Multiplexing (CDM) uses different orthogonal code sequences to distinguish different signal multiplexing methods.

[0234] In some embodiments, multiple optical network units (ONUs) share the same frequency and time resources, but each ONU's bandpass pulse signal is multiplied by a unique pseudo-random code (PN code). The different orthogonal code sequences exhibit good autocorrelation and cross-correlation, allowing the signals from different ONUs to be correctly separated at the receiver through a decoding process.

[0235] In some embodiments, the data to be transmitted in each optical network element is modulated (e.g., CAP, QPSK, etc.) to generate a bandpass pulse signal; a unique pseudo-random code (PN code) is assigned to each optical network element. The pseudo-random code is pre-assigned to each optical network element by the optical line terminal, and the pseudo-random codes among all optical network elements are orthogonal (i.e., the cross-correlation is close to zero).

[0236] In some embodiments, the bandpass pulse signal of each optical network unit can be multiplied bit by bit with the corresponding pseudo-random code to obtain the spread bandpass pulse signal; the corresponding optical signal is generated based on the spread bandpass pulse signal.

[0237] In some embodiments, the optical signals corresponding to the spread bandpass pulse signals of all optical network units can be superimposed together based on a passive optical splitter to form a composite optical signal, which can be transmitted in the same frequency band and at the same time.

[0238] In some embodiments, generating a corresponding optical signal based on multiple filtered subcarrier signals includes: determining a target wavelength based on a preset wavelength division multiplexing rule; and generating an optical signal of the target wavelength based on multiple filtered subcarrier signals.

[0239] Wavelength Division Multiplexing (WDM) is a multiplexing method that transmits multiple optical signals of different wavelengths simultaneously on the same optical fiber.

[0240] In some embodiments, the data to be transmitted in each optical network unit is modulated (e.g., CAP, QPSK, etc.) to generate a bandpass pulse signal; the optical network unit can modulate the corresponding bandpass pulse signal onto an optical carrier of the target wavelength to generate optical signals of different wavelengths.

[0241] In some embodiments, a multiplexer (MUX) can be used to multiplex optical signals of different wavelengths into the same optical fiber to form a composite optical signal. The composite optical signal contains optical signals from all optical network units, but each optical network unit uses a different wavelength for its optical signal.

[0242] Composite optical signals are transmitted over long distances via optical fibers.

[0243] Figure 6 This is an exemplary schematic diagram of time-frequency resource transmission according to some embodiments of this specification.

[0244] like Figure 6 As shown in (a), the same ONU can utilize one or more different modulation schemes, such as MQAM, probabilistic shaping (PS) MQAM, etc., to reuse the same spectrum resources; such as Figure 6 As shown in (b), different ONUs can use different spectrum resources for transmission at the same time; Figure 6 As shown in (c), the ONU can reduce the bandwidth requirements of the transceiver by mixing different time and spectrum resources for time-domain and frequency-domain transmission.

[0245] In some embodiments, multiple subcarrier signals are filtered by multiple filters to obtain multiple filtered subcarrier signals, including: selecting target signals and blank signals from multiple preset signals; and modulating different subcarrier signals onto the corresponding target signals to obtain multiple filtered subcarrier signals.

[0246] The preset signal is the carrier signal to be selected as the target signal.

[0247] The target signal refers to the carrier signal used to carry information in the preset signal.

[0248] Different target signals have different center frequencies and frequency bands. In some embodiments, the target signal may include a first reference signal and a second reference signal, which are orthogonal to each other.

[0249] Each subcarrier signal can modulate different target signals separately.

[0250] Blank signal refers to the idle carrier signal in the preset signal.

[0251] For example, an optical network unit can modulate a subcarrier signal onto a target signal by passing it through two mutually orthogonal filters within the frequency band corresponding to the target signal.

[0252] For example, the optical line terminal can modulate the first reference signal based on the filtered first component signal to obtain the modulated first component signal; and modulate the second reference signal based on the filtered second component signal to obtain the modulated second component signal, thereby realizing the modulation of the subcarrier signal onto the corresponding target signal.

[0253] It should be noted that in carrierless amplitude and phase modulation (CAP) technology, due to its unique "carrierless" design, the optical line terminal lacks a carrier with the same frequency and phase as the optical network unit to eliminate signal components on different transmission paths, which may lead to in-band interference (ICI). To reduce this interference, guard intervals need to be introduced into the signal design to ensure signal clarity and transmission quality.

[0254] Figure 7 This is an exemplary schematic diagram of the uplink and downlink transmission spectrum according to some embodiments of this specification.

[0255] like Figure 7 As shown, the downlink transmission (i.e., the direction in which the optical line terminal sends data to the optical network) uses five 15 GBaud subcarrier signals. Of these, only four subcarrier signals are used to transmit data, while the other subcarrier signal is reserved as a blank subcarrier for mixing detection to improve the detection accuracy of the signal.

[0256] like Figure 7 As shown, compared to the downlink transmission spectrum, uplink transmission (i.e., the direction in which optical network units send data to optical line terminals) further subdivides each 15 GBaud subcarrier into 2 * 7.5 GBaud subcarriers. This subdivision strategy provides more frequency resources for uplink communication, enabling the system to allocate resources more flexibly to meet the needs of different users. In particular, the introduction of dedicated subcarriers allows high-priority users to escape the influence of rogue ONUs that may only exist in the uplink, thereby ensuring the security and reliability of communication. In this embodiment, uplink communication uses QPSK (Quad Phase Keying) modulation, which allows the peak line rate of each ONU to reach 25 Gbit / s, while the total peak line rate of the optical line terminal (OLT) is 100 Gbit / s. This high-speed transmission capability, combined with the advantages of CAP modulation technology, enables the entire uplink communication system to provide efficient and reliable data transmission services.

[0257] In some embodiments, the data to be transmitted can be divided into multiple data segments, and a subcarrier signal corresponding to each data segment is modulated onto a corresponding target signal.

[0258] In some embodiments, a blank signal and a bandpass pulse signal corresponding to the data to be transmitted are combined; an optical signal is generated based on the combined signal and transmitted.

[0259] In some embodiments, the optical network unit can improve signal detection accuracy by mixing the received signal with a blank subcarrier. Mixing detection helps eliminate noise and interference, improving signal quality.

[0260] In some embodiments, the transmitter can use Alamouti coding to preprocess the data to be transmitted, enabling dual-polarization signal detection with a single balanced detector and a single analog-to-digital converter. The total capacity of the system is equivalent to that of a dual-polarization system with the same spectral design.

[0261] In some embodiments of this specification, carrierless amplitude-phase modulation (CAP) technology is used to achieve efficient modulation and transmission of uplink signals, which helps to simplify the system structure, significantly reduce the architecture deployment cost, and maintain high-performance signal processing capabilities.

[0262] Figure 3 This is an exemplary flowchart illustrating demodulated data according to some embodiments of this specification. In some embodiments, process 300 may be executed at the receiving end of a second node in an optical network communication system. Figure 3 As shown, process 300 includes the following steps.

[0263] Step S310: Based on the optical signal received from the transmitter of the first node, obtain the corresponding demodulated data.

[0264] The data to be demodulated is the data corresponding to the data to be transmitted after being transmitted through an optical network.

[0265] The data to be transmitted is the data sent by the first node. For example, the data to be transmitted can be data sent from the optical line terminal to the optical network unit, or data sent from multiple optical network units to the optical line terminal.

[0266] The optical signal can be an optical signal sent from the optical line terminal to the optical network unit, or it can be a composite optical signal sent from multiple optical network units to the optical line terminal.

[0267] In some embodiments, an optical network unit or optical line terminal can convert the received optical signal into an electrical signal corresponding to the data to be transmitted based on a photodetector (such as a PIN diode or an avalanche photodiode), and perform analog-to-digital conversion on the electrical signal corresponding to the data to be transmitted based on an analog-to-digital converter to obtain the data to be demodulated.

[0268] Step S320: The data to be demodulated is filtered by multiple matched filters to obtain multiple subcarriers to be demodulated.

[0269] The subcarrier to be demodulated refers to the signal after a certain independent signal of the data to be transmitted has been modulated or mapped.

[0270] In some embodiments, the receiving end of a node can filter the data to be demodulated based on multiple matched filters to obtain multiple subcarriers to be demodulated.

[0271] The matched filter corresponds to the filter used by the transmitter of the first node in modulating the data to be transmitted. For example, if the initial filter used by the first node in modulating the data to be transmitted is a shaping filter, then the matched filter is the filter obtained by reversing the signal of the initial filter along the time axis (hereinafter referred to as the shaping filter).

[0272] The matched demodulation method corresponds to the modulation method used by the first node during the modulation of the data to be transmitted. For example, if the first node uses CAP modulation, then the matched demodulation method is CAP demodulation.

[0273] Step S330: Demodulate multiple subcarriers to be demodulated into data to be transmitted.

[0274] In some embodiments, the second node can demodulate multiple subcarriers to be demodulated into data to be transmitted using a matched demodulation method. For example, based on the first component signal and the second component signal of the subcarriers to be demodulated, a data segment of the subcarrier to be demodulated can be obtained through constellation mapping, and the data to be transmitted can be obtained based on the data segments of multiple subcarriers to be demodulated.

[0275] In some embodiments, multiple matched filters are used to filter the data to be demodulated to obtain multiple subcarriers to be demodulated, including: filtering the data to be demodulated based on a third filter to obtain a first component signal of the subcarrier to be demodulated; filtering the data to be demodulated based on a fourth filter to obtain a second component signal of the subcarrier to be demodulated; and obtaining the subcarrier to be demodulated based on the first component signal and the second component signal of the subcarrier to be demodulated.

[0276] The third filter is used to obtain the first component signal of a certain demodulated subcarrier.

[0277] The fourth filter is a rectifier used to obtain the second component signal of a certain demodulated subcarrier.

[0278] The third filter is a matched filter that is matched with the first filter; the fourth filter is a matched filter that is matched with the second filter.

[0279] Different subcarrier signals can modulate different target signals. Correspondingly, different subcarrier signals to be demodulated need to be demodulated based on their corresponding target signals.

[0280] In some embodiments, when the data to be transmitted is downlink data, the third filter and the fourth filter are orthogonal to each other.

[0281] In some embodiments, the third filter can be obtained by multiplying the shaping filter by the cosine function, and the fourth filter can be obtained by multiplying the shaping filter by the sinine function.

[0282] In some embodiments, if the subcarrier signal is a bandpass signal modulated from a target signal in a certain frequency band, the subcarrier to be demodulated can be filtered based on the third filter and the fourth filter in that frequency band to obtain the first component signal and the second component signal of the corresponding subcarrier signal.

[0283] In some embodiments, when the data to be transmitted is uplink data, the data to be demodulated is filtered based on a third filter to obtain a first component signal of the subcarrier to be demodulated; the data to be demodulated is filtered based on a fourth filter to obtain a second component signal of the subcarrier to be demodulated, including:

[0284] The data to be demodulated is quadrature demodulated to obtain the first demodulated signal and the second demodulated signal of the subcarrier to be demodulated; the first demodulated signal is filtered based on the third filter to obtain the first component signal of the subcarrier to be demodulated; the second demodulated signal is filtered based on the fourth filter to obtain the second component signal of the subcarrier to be demodulated.

[0285] In some embodiments, orthogonal demodulation can be performed on the data to be demodulated based on the target signal to obtain a first demodulated signal and a second demodulated signal of the subcarrier to be demodulated. For example, orthogonal demodulation can be performed on the data to be demodulated based on multiple target signals (e.g., a first reference signal and a second reference signal) to obtain a first demodulated signal and a second demodulated signal of multiple subcarriers to be demodulated.

[0286] The target signal at the receiver of the second node corresponds one-to-one with the target signal used by the transmitter of the first node during modulation. That is, the transmitter of the first node can divide the data to be transmitted into multiple data segments, and modulate the subcarrier signal of each data segment onto a corresponding target signal or pass it through a filter in the frequency band corresponding to the target signal. When demodulating the filtered subcarrier signal at the receiver, the same target signal needs to be used for demodulation or the same matched filter in the same frequency band needs to be passed through.

[0287] The first demodulated signal and the second demodulated signal refer to two mutually orthogonal signals separated from the data to be demodulated through orthogonal demodulation.

[0288] Figure 5 This is an exemplary schematic diagram of modulation and demodulation in an optical line terminal according to some embodiments of this specification.

[0289] In some embodiments, such as Figure 5As shown, the data segment to be transmitted by the optical line terminal is divided into two paths and mapped to PAM signals. Each PAM signal is passed through a square root raised cosine pulse filter, and the two filtered PAM signals are orthogonally modulated to obtain the filtered subcarrier signal of the data segment. An optical signal is generated based on the multiple filtered subcarrier signals and transmitted.

[0290] In some embodiments, such as Figure 5 As shown, the optical signal propagates through the optical fiber and is detected by a photodetector. The detected electrical signal is then processed in the OLT receiver. Each OLT receiver includes two mixers, two matched filters for the in-phase and positive-path channels respectively, a local oscillator (LO), and a phase rotator. The local oscillator frequency of the signal in the k-th frequency band is f. kc In the case of back-to-back electrical signals, the component signals of the in-phase channel and the component signals of the orthogonal channel recovered in the k-th frequency band are as shown in formula (2):

[0291]

[0292] Among them, (s kI (t)+s kQ (t) represents the data to be demodulated, and g(-t) represents the shaping filter. It is the LO phase that compensates for link delay, y kI (t) represents the component signal recovered in the k-th frequency band (e.g., the in-phase component), y kQ (t) represents the component signal recovered from the k-th frequency band (e.g., the orthogonal component).

[0293] In some embodiments, orthogonal demodulation of the data to be demodulated to obtain a first demodulated signal and a second demodulated signal of the subcarrier to be demodulated includes: coherent demodulation of the data to be demodulated based on a first reference signal to obtain a first demodulated signal of the subcarrier to be demodulated; and coherent demodulation of the data to be demodulated based on a second reference signal to obtain a second demodulated signal of the subcarrier to be demodulated, wherein the first reference signal and the second reference signal are orthogonal.

[0294] In some embodiments, the target signal includes a first reference signal and a second reference signal, wherein the first reference signal and the second reference signal are a quadrature carrier and an in-phase carrier, respectively.

[0295] In some embodiments, a first demodulated signal of the subcarrier to be demodulated is obtained based on the product of a first reference signal and the data to be demodulated; and a second demodulated signal of the subcarrier to be demodulated is obtained based on the product of a second reference signal and the data to be demodulated.

[0296] In some embodiments of this specification, the modulation and demodulation process is optimized by demodulating the downlink coherent signal and modulating the uplink carrierless amplitude and phase, thereby reducing the complexity of signal processing and improving signal transmission efficiency.

[0297] In some embodiments, demodulating the plurality of subcarriers to be demodulated into data to be transmitted includes:

[0298] The first component signal and the second component signal of each of the subcarriers to be demodulated are respectively used as the real part and the imaginary part of the data segment corresponding to the data to be transmitted.

[0299] The real and imaginary components of each data segment are mapped to obtain the data segment of the data to be transmitted, thereby determining the data to be transmitted.

[0300] In some embodiments, at the receiving end of the second node, the received signal is processed by demodulation to recover the real and imaginary components of the subcarrier to be demodulated. Based on the real and imaginary components of the subcarrier to be demodulated, the closest constellation point is found on the constellation diagram to determine the data segment of the original data to be transmitted.

[0301] In some embodiments, the method further includes:

[0302] Based on preset time-division multiplexing rules, the reception time period of the optical signal is determined;

[0303] During the receiving time period, the corresponding optical signal is received from the transmitter of the first node.

[0304] In some embodiments, the optical line terminal can convert optical signals from different optical network units into electrical signals based on photodetectors at different time periods, and then convert them into multiple corresponding subcarriers to be demodulated via analog-to-digital converters. The multiple subcarriers to be demodulated are then demodulated (such as CAP demodulation, QPSK demodulation, etc.) to recover the original data to be transmitted.

[0305] In some embodiments, the method further includes:

[0306] Based on preset code decomposition and multiplexing rules, the target code sequence corresponding to the transmitter of the first node is determined;

[0307] The digital signal corresponding to the optical signal is despread based on the target code sequence to obtain the despread signal, which is used as the data to be demodulated.

[0308] In some embodiments, the optical network terminal can convert the composite optical signal into a corresponding electrical signal based on a photodetector, and then convert it into a corresponding digital signal through an analog-to-digital converter. By using the same pseudo-random code as the optical network unit to perform correlation operations on the corresponding digital signal, the despread signal (i.e., the data to be demodulated) of the optical network unit can be extracted. The despread signal is then demodulated (e.g., CAP demodulation, QPSK demodulation, etc.) to recover the original data to be transmitted.

[0309] In some embodiments, the method further includes:

[0310] Based on the preset wave decomposition and multiplexing rules, the target wavelength corresponding to the transmitting end of the first node is determined;

[0311] The optical signal is separated to obtain the optical signal of the target wavelength.

[0312] In some embodiments, the optical line terminal can receive composite optical signals; and separate optical signals of different wavelengths from the composite optical signals through a demultiplexer (DEMUX); each separated optical signal is converted into an electrical signal by a photodetector, and then converted into corresponding data to be demodulated by an analog-to-digital converter; the data to be transmitted is recovered by demodulating the data to be demodulated (such as CAP demodulation, QPSK demodulation, etc.).

[0313] In some embodiments, the method further includes:

[0314] Identify multiple target signals;

[0315] The demodulated data is demodulated based on each target signal to obtain the demodulated signal of the corresponding subcarrier.

[0316] For details on the implementation of each of the above operations, please refer to the previous examples, which will not be repeated here.

[0317] Figure 10 This is a schematic diagram of the structure of an electronic device according to some embodiments of this specification. For example... Figure 10 As shown, the electronic device 1000 may include a processor 1001 and a memory 1002. The electronic device 1000 may also include one or more of a multimedia component 1003, an input / output (I / O) component 1004, and a communication component 1005. In this embodiment, the electronic device 1000 may be a device that implements the optical network communication method provided in this embodiment.

[0318] In some embodiments, the electronic device 1000 may be implemented based on the Media Access Control (MAC) chip in the ONU and OLT.

[0319] The processor 1001 controls the overall operation of the electronic device 1000 to complete all or part of the steps in the aforementioned optical network communication method. The memory 1002 stores various types of data to support the operation of the auxiliary electronic device 1000. This data may include, for example, instructions for any application or method operating on the auxiliary electronic device 1000, and application-related data such as contact data, sent and received messages, pictures, audio, video, etc. The memory 1002 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Read Only Memory (PROM), Read Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The multimedia component 1003 may include a screen and audio components. The screen may be, for example, a touchscreen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signals may be further stored in memory 1002 or transmitted via communication component 1005. The audio component also includes at least one speaker for outputting audio signals. I / O component 1004 provides an interface between processor 1001 and other interface modules, such as a keyboard, mouse, buttons, etc. These buttons may be virtual or physical buttons. Communication component 1005 is used for wired or wireless communication between the electronic device 1000 and other devices. Wireless communication includes, for example, WiFi, Bluetooth, Near Field Communication (NFC), 2G, 3G, 4G, Narrow Band Internet of Things (NB-IoT), Enhanced Machine Type Communication (eMTC), or other 5G technologies, or combinations thereof, without limitation. Therefore, the corresponding communication component 1005 may include: a WiFi module, a Bluetooth module, an NFC module, etc.

[0320] In an exemplary embodiment, the electronic device 1000 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the optical network communication method described above.

[0321] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, which, when executed by a processor, implement the steps of the optical network communication method described above. For example, the computer-readable storage medium may be the memory 1002 including program instructions, which may be executed by the processor 1001 of the electronic device 1000 to implement or execute the methods, steps, and logic diagrams disclosed in the embodiments of this application.

[0322] Alternatively, when executed by a computer, the instructions are used to implement or perform the methods, steps, and logic diagrams disclosed in the embodiments of this application.

[0323] This application also provides a vehicle equipped with the electronic equipment provided in any of the above embodiments. The electronic equipment is used to execute the optical network communication method provided in any of the above embodiments. The vehicle may be a gasoline-powered vehicle, a plug-in hybrid electric vehicle, or a new energy vehicle, etc., and this specification does not specifically limit it.

[0324] In one embodiment, the vehicle can be configured for fully or partially autonomous driving. For example, the vehicle can control itself while in autonomous driving mode, and can determine the current state of the vehicle and its surrounding environment through human intervention, determine the possible behaviors of at least one other vehicle in the surrounding environment, and determine the confidence level corresponding to the probability of that other vehicle performing a possible behavior, and control the vehicle based on the determined information. When the vehicle is in autonomous driving mode, it can be configured to operate without human interaction.

[0325] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0326] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0327] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Although the descriptions of each embodiment in this application have different focuses, and the parts not described in detail in a certain embodiment can be referred to the relevant embodiments of other embodiments, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of this application without departing from the content of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A method of optical network communication, characterized by, The method is applied to the transmitter of the first node in an optical network communication system, and the method includes: The data to be transmitted is modulated into multiple subcarrier signals; The multiple subcarrier signals are filtered by multiple filters to obtain multiple filtered subcarrier signals, wherein the amplitude and phase of the multiple filtered subcarrier signals are different. Based on the multiple filtered subcarrier signals, a corresponding optical signal is generated and the optical signal is sent to the receiving end of the second node in the optical network communication system.

2. The method of claim 1, wherein, The process of modulating the data to be transmitted into multiple subcarrier signals includes: The data to be transmitted is processed by pulse amplitude modulation to obtain multiple subcarrier signals of the data to be transmitted.

3. The method of claim 1, wherein, The subcarrier signal includes a first component signal and a second component signal.

4. The method of claim 3, wherein, The step of filtering the multiple component signals using multiple filters to obtain multiple filtered subcarrier signals includes: The first component signal is filtered based on the first filter to obtain the filtered first component signal; The second component signal is filtered based on the second filter to obtain the filtered second component signal; The filtered subcarrier signal is obtained based on the filtered first component signal and the filtered second component signal.

5. The method of claim 4, wherein, When the data to be transmitted is uplink data, the first filter and the second filter are orthogonal to each other.

6. The method of claim 4, wherein, When the data to be transmitted is downlink data, obtaining the filtered subcarrier signal based on the filtered first component signal and the filtered second component signal includes: The filtered first component signal and the filtered second component signal are quadrature modulated respectively to obtain the modulated first component signal and the modulated second component signal; The filtered subcarrier signal is obtained based on the modulated first component signal and the modulated second component signal.

7. The method of claim 6, wherein, The step of performing quadrature modulation on the filtered first component signal and the filtered second component signal to obtain modulated first component signal and modulated second component signal includes: The first reference signal is modulated based on the filtered first component signal to obtain the modulated first component signal; The second reference signal is modulated based on the filtered second component signal to obtain the modulated second component signal, wherein the first reference signal and the second reference signal are orthogonal.

8. The method of claim 1, wherein, The process of generating corresponding optical signals based on the multiple filtered component signals includes: The multiple filtered subcarrier signals are superimposed to obtain a bandpass pulse signal; The optical signal is the optical signal corresponding to the bandpass pulse signal.

9. The method according to claim 1, characterized in that, The process of modulating the data to be transmitted into multiple subcarrier signals includes: The multiple data segments of the data to be transmitted are mapped respectively to obtain the real part and the imaginary part corresponding to each data segment; The plurality of subcarrier signals are determined based on the real component and the imaginary component corresponding to each data segment.

10. The method according to claim 1, characterized in that, The generation of the corresponding optical signal based on the multiple filtered subcarrier signals includes: Based on preset time-division multiplexing rules, the transmission time period of the optical signal is determined; A corresponding optical signal is generated during the transmission time period.

11. The method according to claim 1, characterized in that, The generation of the corresponding optical signal based on the multiple filtered subcarrier signals includes: The target code sequence is determined based on the preset code division multiplexing rules; Based on the target code sequence, the multiple filtered subcarrier signals are spread to obtain the spread signal; A corresponding optical signal is generated based on the spread spectrum signal.

12. The method according to claim 1, characterized in that, Based on the multiple filtered subcarrier signals, a corresponding optical signal is generated, including: The target wavelength is determined based on the preset wavelength division multiplexing rules; The optical signal of the target wavelength is generated based on the multiple filtered subcarrier signals.

13. The method according to claim 1, characterized in that, The step of filtering the multiple subcarrier signals using multiple filters to obtain multiple filtered subcarrier signals includes: Filter the target signal and blank signal from multiple preset signals; Different subcarrier signals are modulated onto the corresponding target signal to obtain the multiple filtered subcarrier signals.

14. The method according to claim 13, characterized in that, The method further includes: The blank signal and the bandpass pulse signal corresponding to the data to be transmitted are combined; An optical signal is generated and transmitted based on the synthesized signal.

15. An optical network communication method, characterized in that, The method is applied to the receiving end of the second node in an optical network communication system, and the method includes: Based on the optical signal received from the transmitter of the first node, the data to be demodulated is obtained; The data to be demodulated is filtered by multiple matched filters to obtain multiple subcarriers to be demodulated; The plurality of subcarriers to be demodulated are demodulated into data to be transmitted.

16. The method according to claim 15, characterized in that, The step of filtering the data to be demodulated using multiple matched filters to obtain multiple subcarriers to be demodulated includes: The data to be demodulated is filtered using a third-wave filter to obtain the first component signal of the subcarrier to be demodulated. The data to be demodulated is filtered using a fourth-wave filter to obtain the second component signal of the subcarrier to be demodulated. The subcarrier to be demodulated is obtained based on the first component signal and the second component signal of the subcarrier to be demodulated.

17. The method according to claim 16, characterized in that, When the data to be transmitted is downlink data, the third filter and the fourth filter are orthogonal to each other.

18. The method according to claim 16, characterized in that, When the data to be transmitted is uplink data, the data to be demodulated is filtered based on the third wave filter to obtain the first component signal of the subcarrier to be demodulated. The data to be demodulated is filtered using a fourth-wave filter to obtain the second component signal of the subcarrier to be demodulated, including: The data to be demodulated is quadrature demodulated to obtain the first demodulated signal and the second demodulated signal of the subcarrier to be demodulated; The first demodulated signal is filtered by the third filter to obtain the first component signal of the subcarrier to be demodulated. The second demodulated signal is filtered by the fourth filter to obtain the second component signal of the subcarrier to be demodulated.

19. The method according to claim 18, characterized in that, The step of performing orthogonal demodulation on the data to be demodulated to obtain the first demodulated signal and the second demodulated signal of the subcarrier to be demodulated includes: Based on the first reference signal, the data to be demodulated is coherently demodulated to obtain the first demodulated signal of the subcarrier to be demodulated; The data to be demodulated is coherently demodulated based on the second reference signal to obtain the second demodulated signal of the subcarrier to be demodulated, wherein the first reference signal and the second reference signal are orthogonal.

20. The method according to claim 15, characterized in that, The step of demodulating the plurality of subcarriers to be demodulated into data to be transmitted includes: The first component signal and the second component signal of each of the subcarriers to be demodulated are respectively used as the real part and the imaginary part of the data segment corresponding to the data to be transmitted; The real and imaginary components of each data segment are mapped to obtain the data segment of the data to be transmitted, thereby determining the data to be transmitted.

21. The method according to claim 15, characterized in that, The method further includes: Based on preset time-division multiplexing rules, the reception time period of the optical signal is determined; During the receiving time period, the corresponding optical signal is received from the transmitter of the first node.

22. The method according to claim 15, characterized in that, The method further includes: Based on preset code decomposition and multiplexing rules, the target code sequence corresponding to the transmitter of the first node is determined; The digital signal corresponding to the optical signal is despread based on the target code sequence to obtain the despread signal, which is used as the data to be demodulated.

23. The method according to claim 15, characterized in that, The method further includes: Based on the preset wave decomposition and multiplexing rules, the target wavelength corresponding to the transmitting end of the first node is determined; The optical signal is separated to obtain the optical signal of the target wavelength.

24. The method according to claim 15, characterized in that, The method further includes: Identify multiple target signals corresponding to the transmitter of the first node; The demodulated data is demodulated based on each target signal to obtain the demodulated signal of the corresponding demodulated subcarrier.

25. A transmitting end, characterized in that, The transmitting end includes at least one digital-to-analog converter and at least one optical modulator, wherein the at least one digital-to-analog converter and the at least one optical modulator are electrically connected; wherein... The digital-to-analog converter is used to perform digital-to-analog conversion based on multiple filtered subcarriers to obtain the corresponding analog signal, and then send it to the optical modulator; The optical modulator is used to modulate the optical carrier based on the analog signal and output an optical signal corresponding to the data to be transmitted.

26. The transmitting end according to claim 25, characterized in that, The number of digital-to-analog converters is 1.

27. The transmitting end according to claim 25, characterized in that, The optical modulator is a Mach-Zehnder modulator.

28. The transmitting end according to claim 27, characterized in that, The phase bias voltage of one arm of the Mach-Zehnder modulator is zero, while the phase of the other arm is controlled by the analog signal corresponding to the plurality of filtered subcarrier signals.

29. A receiving end, characterized in that, The receiving end includes at least one photodetector and at least one analog-to-digital converter, wherein the at least one photodetector and the at least one analog-to-digital converter are electrically connected; wherein... The photodetector is used to perform photoelectric conversion on the optical signal corresponding to the data to be transmitted, to obtain the electrical signal corresponding to the data to be transmitted, and send it to the analog-to-digital converter; The analog-to-digital converter is used to perform analog-to-digital conversion based on the electrical signal corresponding to the data to be transmitted, to obtain the data to be demodulated, so as to determine the data to be transmitted.

30. The receiving end according to claim 29, characterized in that, The number of photodetectors is 1, and the number of analog-to-digital converters is 1.

31. The receiving end according to claim 29, characterized in that, The receiving end also includes a local oscillator, which is used to generate the target signal.

32. The receiving end according to claim 29, characterized in that, The receiving end also includes a phase rotator, which is used to cause a phase shift in the target signal to obtain a first reference signal and a second reference signal.

33. An optical network communication system, characterized in that, The system includes at least one node, the node comprising a transmitter as described in any one of claims 25-28 and a receiver as described in any one of claims 29-32.

34. The system according to claim 33, characterized in that, The at least one node is an optical network unit or an optical line terminal, and at least one of the optical network units and the optical line terminal are connected by an optical fiber medium.

35. The system according to claim 34, characterized in that, The transmitter of the optical network unit is connected to the receiver of the optical line terminal via an optical fiber medium. The receiver of the optical network unit is connected to the transmitter of the optical line terminal via an optical fiber medium.

36. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer-readable storage medium stores instructions that, when executed by a computer, cause the computer to perform the optical network communication method according to any one of claims 1 to 24.

37. A computer program product, characterized in that, The computer program product stores instructions that, when executed by a computer, cause the computer to perform the optical network communication method according to any one of claims 1 to 24.

38. An electronic device, characterized in that, include: A memory on which computer programs are stored; A processor for executing the computer program in the memory to implement the optical network communication method according to any one of claims 1 to 24.

39. A vehicle, characterized in that, Includes the optical network communication system according to any one of claims 33 to 35, or the electronic device according to claim 38, or the optical network communication method according to any one of claims 1 to 24.

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