Access device, processing device, method, device and computer readable medium

Abstract

The embodiment of the invention relates to access equipment, processing equipment, a related method, a related device and a medium. In an aspect, an access device receives at least one carrier signal and control information from a processing device. And the access device processes a target carrier signal in the at least one carrier signal based on the control information. The access device modulates the target carrier signal based on the control information to generate a modulated signal, wherein the modulated signal is combined with a further modulated signal of a further one or more access devices at the processing device to form a digital subcarrier modulated (DSCM) signal. The access device then transmits the modulated signal to the processing device. According to the embodiment of the invention, the carrier signals are uniformly issued through the processing equipment, so that aliasing of modulated signals from different access equipment in a frequency domain is reduced, the quality of the DSCM signals is improved, and the implementation of a flexible high-speed optical network is facilitated.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of communication technology, and more particularly to an access device, a processing device, a related method, a related apparatus, and a computer-readable medium. Background Art

[0002] With the explosive growth of Internet data services, the transmission capacity required for core networks, metropolitan area networks and access networks has grown rapidly over time. Higher baud rates, higher-order modulation formats, advanced digital signal processing (DSP) and forward error correction coding (FEC), as well as other advanced digital communication technologies, have recently been adopted by the industry, further pushing the network throughput to its limits.

[0003] In order to cope with the current rapid business evolution, efficient use of the already deployed fiber infrastructure is an important way to postpone the expensive deployment of new fiber. In this strategy, the flexible slicing capability of the transmission signal is the primary factor to achieve more efficient network resource management. However, traditional coherent schemes based on single carrier modulation lack this capability. Summary of the invention

[0004] In general, the example embodiments of the present disclosure relate to a technical solution in which a processing device uniformly sends carrier signals to multiple access devices, and the access devices process and / or modulate the target carrier signals, so as to optimize the performance of a point-to-multipoint (PtMP) coherent digital subcarrier modulation (DSCM) system.

[0005] In a first aspect of the disclosure, an access device is provided. The access device includes: at least one processor and at least one memory. The at least one memory stores instructions, and when the instructions are executed by the at least one processor, the access device at least: receives at least one carrier signal and control information from the processing device; processes a target carrier signal in the at least one carrier signal based on the control information; modulates the target carrier signal based on the control information to generate a modulated signal, wherein the modulated signal and another modulated signal of one or more other access devices will be combined at the processing device to form a digital subcarrier modulation (DSCM) signal; and sends the modulated signal to the processing device.

[0006] In a second aspect of the disclosure, a processing device is provided. The processing device includes: at least one processor and at least one memory. The at least one memory stores instructions, and when the instructions are executed by the at least one processor, the processing device at least: determines at least one carrier signal and control information for an access device; sends at least one carrier signal and control information to the access device; and receives a modulated signal from the access device, wherein the modulated signal is generated by modulating a target carrier signal in the at least one carrier signal based on the control information, and wherein the modulated signal is combined with another modulated signal of one or more other access devices at the processing device to form a digital subcarrier modulation (DSCM) signal.

[0007] In a third aspect of the disclosure, a method is provided. The method includes: receiving at least one carrier signal and control information from a processing device at an access device; processing a target carrier signal in the at least one carrier signal based on the control information; modulating the target carrier signal based on the control information to generate a modulated signal, wherein the modulated signal and another modulated signal of another one or more access devices are combined at the processing device to form a digital subcarrier modulation (DSCM) signal; and sending the modulated signal to the processing device.

[0008] In a fourth aspect of the disclosure, a method is provided. The method includes: determining at a processing device at least one carrier signal and control information for an access device; sending at least one carrier signal and control information to the access device; and receiving a modulated signal from the access device, wherein the modulated signal is generated by modulating a target carrier signal in the at least one carrier signal based on the control information, and wherein the modulated signal is combined with another modulated signal of one or more other access devices at the processing device to form a digital subcarrier modulation (DSCM) signal.

[0009] In a fifth aspect of the disclosure, an apparatus is provided. The apparatus includes: a component for receiving at least one carrier signal and control information from a processing device at an access device; a component for processing a target carrier signal in the at least one carrier signal based on the control information; a component for modulating the target carrier signal based on the control information to generate a modulated signal, wherein the modulated signal and another modulated signal of another one or more access devices will be combined at the processing device to form a digital subcarrier modulation (DSCM) signal; and a component for sending the modulated signal to the processing device.

[0010] In a sixth aspect of the disclosure, an apparatus is provided. The apparatus includes: a component for determining at least one carrier signal and control information for an access device at a processing device; a component for sending at least one carrier signal and control information to the access device; and a component for receiving a modulated signal from the access device, wherein the modulated signal is generated by modulating a target carrier signal in at least one carrier signal based on the control information, and wherein the modulated signal is combined with another modulated signal of one or more other access devices at the processing device to form a digital subcarrier modulation (DSCM) signal.

[0011] In a seventh aspect of the present disclosure, a non-transitory computer-readable medium is provided, comprising program instructions for causing an apparatus to execute at least any one of the methods of the third to fourth aspects.

[0012] In an eighth aspect of the present disclosure, a computer program is provided. When executed by a device, the computer program causes the device to perform at least any one of the methods of the third to fourth aspects.

[0013] In a ninth aspect of the present disclosure, an access device is provided. The access device comprises: a receiving circuit configured to receive at least one carrier signal and control information from a processing device; a processing circuit configured to process a target carrier signal in the at least one carrier signal based on the control information; a modulation circuit configured to modulate the target carrier signal based on the control information to generate a modulation signal, wherein the modulation signal and another modulation signal of one or more other access devices will be combined at the processing device to form a digital subcarrier modulation (DSCM) signal; and a transmitting circuit configured to transmit the modulation signal to the processing device.

[0014] In a tenth aspect of the present disclosure, a processing device is provided. The processing device includes: a determination circuit configured to determine at least one carrier signal and control information for an access device; a sending circuit configured to send at least one carrier signal and control information to the access device; and a receiving circuit configured to receive a modulated signal from the access device, wherein the modulated signal is generated by modulating a target carrier signal in at least one carrier signal based on the control information, and wherein the modulated signal is combined with another modulated signal of one or more other access devices at the processing device to form a digital subcarrier modulation (DSCM) signal.

[0015] It should be understood that the contents described in the Summary of the Invention are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without exceeding the scope of protection required by the present application.

[0017] Figure 1A A block diagram of an example communication system is shown in which embodiments of the present disclosure may be implemented.

[0018] Figure 1B The spectrum comparison of DSCM signal and single carrier signal is shown.

[0019] Figure 1C A block diagram of an example communication system is shown in which embodiments of the present disclosure may use DSCM techniques.

[0020] Figure 1D The figure shows the comparison between the ideal DSCM signal and the uplink DSCM signal in the actual system.

[0021] Figure 2 A schematic diagram of the interaction process between an access device and a processing device according to an embodiment of the present disclosure is shown.

[0022] Figure 3A A schematic diagram of a carrier selective repeater (CSR) according to an embodiment of the present disclosure is shown.

[0023] Figure 3B The heating frequency shift process of the microring resonator (MRR) according to the embodiment of the present disclosure is shown.

[0024] Figure 3C The process of selecting a signal by using the vernier effect in the MRR according to the embodiment of the present disclosure is shown.

[0025] Figure 3D A schematic diagram of the working process of the CSR according to an embodiment of the present disclosure is shown.

[0026] Figure 4 A block diagram of an example communication system and its internal components is shown in which embodiments of the present disclosure may be implemented.

[0027] Figure 5 A schematic diagram of a CSR module and its internal components according to an embodiment of the present disclosure is shown.

[0028] Figure 6 A schematic diagram showing the relationship between a carrier signal and a subcarrier modulation signal in a frequency spectrum according to an embodiment of the present disclosure is shown.

[0029] Figure 7A schematic diagram of the interaction process between an access device and a processing device according to an embodiment of the present disclosure is shown.

[0030] Fig. 8A A block diagram of an example communication system is shown in which embodiments of the present disclosure can upload and download signals and perform carrier allocation and modulation.

[0031] Figure 8B A schematic diagram showing the process of selecting a target carrier signal and modulating a subcarrier signal by an access device according to an embodiment of the present disclosure.

[0032] Fig. 9 A schematic diagram of a process executed by an access device according to some embodiments of the present disclosure is shown.

[0033] Fig.10 A schematic diagram of a flow chart executed by a processing device according to some embodiments of the present disclosure is shown.

[0034] Fig.11 A simplified block diagram of an electronic device suitable for implementing embodiments of the present disclosure is shown.

[0035] Fig.12 A schematic diagram of a computer-readable medium suitable for implementing an embodiment of the present disclosure is shown.

[0036] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0037] The principles and spirit of the present disclosure will be described below with reference to several exemplary embodiments shown in the accompanying drawings. It should be understood that these specific embodiments are described only to enable those skilled in the art to better understand and implement the present disclosure, and are not intended to limit the scope of the present disclosure in any way.

[0038] As used herein, the term "including" and similar terms should be understood as open inclusion, i.e., "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0039] As used herein, the term "determine" covers a variety of actions. For example, "determine" may include operation, calculation, processing, export, investigation, search (e.g., search in a table, a database or another data structure), ascertain, etc. In addition, "determine" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. In addition, "determine" may include parsing, selecting, selecting, establishing, etc. As used herein, "at least one of the following: " and "at least one of " and similar expressions, wherein a list of two or more elements is connected by "and" or "or", means at least any one of these elements, or at least any two or more of these elements, or at least all of them.

[0040] As used herein, the term "circuitry" refers to one or more of: (a) hardware circuit implementations only (such as implementations of analog and / or digital circuits only); and (b) combinations of hardware circuits and software, such as (where applicable): (i) a combination of analog and / or digital hardware circuits and software / firmware, and (ii) any portion of a hardware processor with software (including a digital signal processor, software, and memory that work together to enable an apparatus such as a radio frequency device or other computing device to perform various functions); and (c) hardware circuits and / or processors, such as a microprocessor or portion of a microprocessor, that require software (e.g., firmware) for operation, but may be without software when software is not required for operation.

[0041] The definition of circuitry applies to all uses of this term in this application, including in any claims. As another example, the term "circuitry" as used herein also covers an implementation of a hardware circuit or processor (or multiple processors), or a portion of a hardware circuit or processor, or accompanying software or firmware. For example, the term "circuitry" also covers a baseband integrated circuit or a processor integrated circuit or similar integrated circuit in other computing devices if applicable to the particular claim notation.

[0042] Digital Sub-Carrier Multiplexing (DSCM) is a modulation technology in the field of optical fiber communication. It multiplexes multiple low-rate optical signals into a high-speed signal in the frequency domain to achieve higher bandwidth utilization in optical fiber transmission. DSCM technology uses digital signal processing technology to subdivide the transmission spectrum into multiple digital sub-carriers (SC), modulate different signals on different sub-carrier frequencies for transmission, and the receiving end separates these optical signals through demodulation.

[0043] The embodiments of the present disclosure propose a technical solution in which a processing device sends down a carrier signal and control information, and an access device processes and modulates the carrier signal based on the control information and sends it to the processing device. This solution optimizes the quality of the uplink DSCM signal of the point-to-multipoint system and improves the efficiency and rate of signal transmission.

[0044] Figure 1A 1 shows a block diagram of an example communication system in which embodiments of the present disclosure may be implemented. Figure 1A As shown, the communication system 100 includes at least one access device 110, such as access devices 110-1, 110-2...110-8, and a processing device 120. The access device 110 includes a transmitting device of an optical network unit (ONU) in a passive optical network (PON), a transmitting device of an access point (AP) in a wireless backhaul network, and a device for converting a wired network into a wireless network to connect wireless terminal devices such as computers, mobile phones, and tablets to the network, such as a wireless router, a wireless access point, and a wireless gateway. The processing device 120 includes, for example, an optical line terminal (OLT) in a passive optical network, a central processing unit (CPU) in a wireless backhaul network, etc., which includes components such as a digital subcarrier input interface, a coherent demodulator, a digital signal processor, a DSCM signal output interface, a controller, and a memory to achieve reception and demodulation of DSCM signals. At least one access device 110 sends a digital subcarrier signal modulated with valid information to the processing device 120, and the processing device 120 synthesizes a DSCM signal.

[0045] Figure 1B Figure 2 shows the frequency domain waveform comparison between DSCM signal and single carrier signal. Figure 1B As shown, compared with single-carrier signals, DSCM signals have many advantages. The coherent DSCM system can flexibly allocate different modulation formats, subcarrier numbers and bandwidths, signal powers, etc. to different access devices, thereby being able to solve the problem of flexible slicing of transmission signals. Figure 1BThe digital carrier signal (single carrier signal) has a baud rate of 1*50GBaud / s, while the DSCM digital subcarrier signal has a baud rate of 8*6.25GBaud / s. Compared with the single carrier signal, the DSCM digital subcarrier signal has the advantages of high bandwidth utilization, strong multiple access capability, high tolerance to linear and nonlinear damage, and low enhanced equalization phase noise (EEPN). However, it also has the problems of high complexity and low peak power to average power ratio (PAPR).

[0046] DSCM technology flexibly aggregates multiple low-speed signals at different endpoints in different locations into a high-speed DSCM signal. Figure 1C A block diagram of an example communication system in which embodiments of the present disclosure may use DSCM techniques is shown. Figure 1C As shown in the figure, three different Spoke devices upload subcarrier signals 10, 20 and 80 to the Hub device respectively, which brings about the problem that subcarrier signals from different endpoints are aliased. Different endpoints use their own transmitting devices Tx, such as directly modulated laser (DML), electro-absorption modulated laser (EML), edge emitting laser (EEL), vertical cavity surface emitting laser (VECSEL), etc. to transmit subcarrier signals, and it is common for laser wavelength to drift. Although the degree of wavelength drift of lasers of different qualities will be different, they will definitely cause different degrees of signal errors. Data carriers from different endpoints will collide in the frequency domain, that is, subcarrier signals will be aliased.

[0047] Figure 1D The figure shows the comparison between the ideal DSCM signal and the uplink DSCM signal in the existing actual system. Figure 1DAs shown, ideally, the spectrum of the aggregated signal in the Hub device is similar to the spectrum on the left, the digital subcarrier signals are continuous and separated from each other in the spectrum, and each subcarrier signal occupies a part of the bandwidth. However, due to the drift of the laser wavelength in the laser, the data subcarriers from the 8 endpoints will collide in the frequency domain as shown in the right figure, where subcarrier signal 10 and subcarrier signal 20 are aliased in the frequency domain. The bandwidth of currently commercial high-speed data carrier devices is in the range of 25-50GHz. If 4 to 16 subcarrier SCs are used to implement DSCM technology, the bandwidth of each subcarrier SC is about several GHz. As we know, 1GHz corresponds to a laser with a wavelength of 1550nm and a resolution of 8pm. Due to the limited wavelength accuracy of the laser, collisions are easy to occur, resulting in a decrease in the performance of the DSCM signal in transmitting valid data or even data transmission failure.

[0048] In some embodiments, Figure 1A The access device 110 in the example can be called an access point (AP), an optical network unit (ONU), or an endpoint, and the processing device 120 is called a processing unit (CPU), an optical line terminal (OLT), or a relay point based on its function. According to the connection relationship and topological structure between the access device 110 and the processing device 120, in some embodiments, the access device 110 is also called a spoke device, and the processing device 120 is also called a hub device. The access device and the processing device upload and download optical signals via optical transmission media such as optical fibers. An optical transmitting device Tx is arranged at the access device 110, and an optical receiving device Rx is arranged at the processing device 120. Therefore, in some embodiments, the access device 110 is also called Tx, and the processing device 120 is also called Rx. In addition, Figure 1A The connection structure between the access device 110 and the processing device 120 is only schematically shown, wherein data from eight access devices 110 are aggregated in one processing device 120. It should be noted that the number of the access devices 110 and the processing devices 120 in the embodiment of the present disclosure is not limited to the above example.

[0049] Figure 2 A schematic diagram of the interaction process between an access device and a processing device according to some embodiments of the present disclosure is shown. Figure 1A , taking the access device 110 as the access device in process 200 and the processing device 120 as the processing device in process 200 as an example. Figure 2In the example process 200, first, the access device 110 receives (230) at least one carrier signal 205 and control information 215 from the processing device 120. The at least one carrier signal 205 may be a frequency comb signal, which includes one or more optical signals with approximately equal frequency intervals. The control information 215 is used to instruct the access device 110 how to process and / or modulate the at least one received carrier signal 205. The control information 215 includes, for example, the position information of the target carrier signal on the spectrum, the number and bandwidth of the signal modulation subcarriers, the modulation mode of the subcarriers, the signal power, etc. The at least one carrier signal 205 and the control information 215 are determined (210) by the processing device 120 for the access device 110, and then sent (220) to the access device 110 through an optical transmission medium such as an optical fiber. By uniformly sending down the carrier signal through the processing device 120, rather than generating the carrier signal by the transmitting device Tx at the access device 110, the collision of the subcarrier signal in the frequency domain caused by the wavelength drift of the laser is avoided or reduced.

[0050] After receiving at least one carrier signal 205 and control information 215 sent by the processing device 120, the access device 110 processes (240) the target carrier signal in the at least one carrier signal 205 based on the control information 215. In some embodiments, the at least one carrier signal 205 includes, for example, multiple frequency comb signals. The access device 110 first selects a target carrier signal from the multiple frequency comb signals based on the position of the target carrier signal on the spectrum indicated in the control information 215. The target carrier signal is a carrier signal to be used that is allocated to the access device 110 by the processing device 120. After obtaining the target carrier signal through frequency selection, the access device 110 processes (240) the target carrier signal. For example, the processing (240) of the target carrier signal by the access device 110 may include amplifying the selected target carrier signal to compensate for the signal attenuation caused by the transmission and distribution process from the processing device 120. For another example, the processing (240) of the target carrier signal by the access device 110 may also include filtering the amplified target carrier signal to reduce the noise on the spectrum introduced by the amplification.

[0051] In some other embodiments, at least one carrier signal 205 includes, for example, a single optical carrier signal, and the single carrier signal is a target carrier signal to be used that is allocated to the access device 110 by the processing device 120. In such an embodiment, the processing (240) of the target carrier signal by the access device 110 may include amplifying the target carrier signal, and filtering the amplified target carrier signal based on the position of the target carrier signal on the spectrum indicated in the control information 215. It is easy for a person skilled in the art to understand that the above-mentioned processing (220) of the target carrier signal may include the above-mentioned general operations of amplifying and filtering the target carrier signal, and may also include other processing processes for the target carrier signal. Any processing process that processes the target carrier signal in the at least one carrier signal 205 uniformly sent by the processing device 120 into a signal that can be used by the access device 110 (can be used for modulation or sending effective information) is applicable to this embodiment.

[0052] After obtaining the processed target carrier signal, the access device 110 may modulate (250) the target carrier signal based on the control information 215 to generate a modulated signal 225. In some embodiments, the access device 110 modulates the target carrier signal based on the number and position of subcarriers, the modulation format of the subcarriers, etc. indicated in the control information 215 to generate the modulated signal 225. The modulated signal 225 will be used by the access device 110 to send valid information to the processing device 120, and will be combined with another modulated signal 225 of one or more other access devices 110 at the processing device 120 to form a digital subcarrier modulation (DSCM) signal.

[0053] Then, the access device 110 may send (260) the modulated signal 225 to the processing device 120. The processing device 120 receives (270) the modulated signal 225 from the access device 110, and combines multiple modulated signals 225 uploaded by multiple access devices 110 into a DSCM signal, and transmits it through a channel. The corresponding signal receiving end Rx may use a coherent demodulator to demodulate and obtain the data sent to the receiving end.

[0054] Also refer to Figure 1A , Figure 1AThe subcarrier signals (i.e., modulated signals 225) uploaded by the eight endpoints (i.e., access devices 110) shown in the figure may be generated based on the same target carrier signal or may be generated based on different target carrier signals. The processing device 120 may combine multiple subcarrier signals generated based on the same target carrier signal or may separately combine multiple subcarrier signals generated based on different target carrier signals. For example, the subcarrier signals uploaded by access devices 110-1, 110-2, 110-3 and 110-4 are generated based on the same target carrier signal, and the processing device 120 combines the subcarrier signals from access devices 110-1, 110-2, 110-3 and 110-4 into a complete DSCM signal and transmits it; the subcarrier signals uploaded by access devices 110-5, 110-6, 110-7 and 110-8 are generated based on the same target carrier signal, and the processing device 120 combines the subcarrier signals from access devices 110-5, 110-6, 110-7 and 110-8 into a complete DSCM signal and transmits it.

[0055] The embodiments of the present disclosure propose a solution for uniformly sending down carrier signals through a processing device, thereby reducing the aliasing of modulated signals from different access devices in the frequency domain, improving the quality of DSCM signals, and facilitating the realization of a flexible high-speed optical network.

[0056] In some embodiments of the present disclosure, the processing of the target carrier signal in the at least one carrier signal 205 in the interaction process 200 is completed by a carrier selecting repeater (CSR) deployed at the access device 110 .

[0057] In some embodiments, at least one carrier signal 205 comprises, for example, a frequency comb signal. Figure 3A A schematic diagram of the CSR in these embodiments is shown, Figure 3A As shown, the CSR includes a first micro ring resonator (Micro Ring Resonator) MRR1, which receives at least one carrier signal 205 sent by the processing device 120. By heating the waveguide of MRR1, the resonant wavelength of MRR1 is adjusted to move the passband of multiple passbands of MRR1 to the frequency position of the target carrier signal, thereby selecting the target carrier signal from the at least one carrier signal 205.

[0058] The working principle of the first microring resonator is described exemplarily below. The resonant wavelength of MRR1 is moved by heating the microheater deposited on the first microring resonator MRR1, thereby selecting the desired carrier. In this process, the vernier effect is applied to the alignment of the resonant wavelength of MRR1 with the selected carrier, reducing the frequency shift of the transmission spectrum of MRR1, thereby reducing the delay. By moving the resonant wavelength of MRR1, the carrier signal that needs to be selected in the multiple frequency comb signals sent down is aligned, that is, the target carrier signal is screened out from at least one carrier signal.

[0059] Figure 3B The heating frequency shift process of the microring resonator is shown. Figure 3B As shown, the optical transmission spectrum of MRR1 is Figure 3B As shown in the left figure. Due to the resonance effect, it exhibits multiple bandpass filter effects. For example, the free spectral range (FSR) of MRR1 is compatible with the frequency interval of the transmitted frequency comb. The microheater deposited on the arm of MRR1 can move the transmission spectrum of MRR1 by heating with electric current, such as Figure 3B As shown in the right figure.

[0060] Figure 3C The figure shows the process of MRR using the cursor effect to select the signal. Figure 3C As shown, for an ordinary bandpass filter with only one passband, if you want to pick out another carrier signal instead of the previously used carrier signal, you need to shift the frequency by a frequency interval equal to the frequency interval between two successive carrier signals (assuming that the frequency interval between adjacent carrier signals is 45 GHz). However, by using the carrier selection repeater CSR provided by some embodiments of the present disclosure, by using a microring resonator MRR1 with multiple passbands, it is only necessary to shift a smaller frequency interval difference (the difference between adjacent passbands of the microring resonator) of 5 GHz, thereby reducing the delay and energy of the heating process in the microring resonator MRR.

[0061] Continue to refer Figure 3A In some embodiments of the present disclosure, the CSR further comprises a semiconductor optical amplifier (Semiconductor Optical Amplifier) ​​SOA and a second microring resonator MRR2, the input end of the semiconductor optical amplifier SOA is coupled to the output end of MRR1, and the output end of SOA is coupled to the input end of MRR2, wherein:

[0062] Based on the signal power information indicated in the control information 215, the SOA amplifies the target carrier signal. Figure 3AThe example in which the CSR includes a single semiconductor optical amplifier SOA is only schematically shown. It is easy for a person skilled in the art to understand that in this example, a plurality of cascaded semiconductor optical amplifiers may also be used to amplify the target carrier signal.

[0063] MRR2 receives the amplified target carrier signal and filters the amplified target carrier signal by adjusting the resonant wavelength of MRR2 to filter out amplified spontaneous emission (ASE) noise introduced by the SOA.

[0064] In some embodiments of the present disclosure, MRR1, MRR2 and the SOA connected in series therebetween constitute a carrier selection repeater CSR. In some embodiments, the desired carrier can be selected by moving the resonant wavelength of MRR1. The vernier effect is used for alignment to reduce the frequency shift of the transmission spectrum of MRR1.

[0065] The SOA connected in series between the MRRs amplifies the selected target carrier signal to compensate for the optical power loss caused by optical fiber transmission and power distribution between multiple access devices. In some embodiments, the signal power of the target carrier signal can be adjusted by adjusting the input current of the SOA so that the power of the subcarrier signal uploaded by each access device meets the requirement of power balance of each subcarrier in the coherent DSCM signal. In some embodiments of the present disclosure, the optical loss of the carrier signal during transmission and power distribution is very large, which can be compensated by using a cascaded SOA.

[0066] MRR2 is used to filter out the ASE noise caused by the SOA. MRR2 is a replica of MRR1 with the same layout area and FSR. In addition, the same or similar (within a preset range) temperature control is applied in the two MRRs to ensure the same frequency shift of the resonant wavelength.

[0067] In some embodiments of the present disclosure, MRR1, MRR2 and SOA can be manufactured using photonic integrated circuit (PIC) technology, making the CSR module compact, energy-efficient and cost-effective. This is very beneficial to the application of CSR in the field of optical access, which requires small size, high power efficiency and low cost.

[0068] The CSR process of optical signal is as follows: Figure 3D As shown, at least one carrier signal 215 includes multiple frequency comb signals with the same frequency interval. Through the tuning of MRR1, the target carrier signal is selected, and the target carrier signal is amplified by SOA. The background noise of spontaneous radiation is generated during the amplification process. The amplified target carrier signal is then filtered by MRR2. Through the tuning of MRR2, the signal frequency is aligned and the noise of other frequencies on the spectrum is filtered out.

[0069] In some embodiments, at least one carrier signal 205 includes, for example, a single optical carrier signal, and the CSR includes a semiconductor optical amplifier SOA and a second microring resonator MRR2. In a single wavelength system, the target carrier signal is amplified by the SOA through coupling with the MRR2 based on the signal power information indicated in the control information 215. MRR2 receives the amplified target carrier signal, and based on the position information of the target carrier signal on the spectrum indicated in the control information 215, the amplified target carrier signal is filtered by adjusting the resonant wavelength of MRR2 to filter out the amplified spontaneous emission (ASE) noise introduced by the SOA.

[0070] In some embodiments of the present disclosure, the access device 110 further includes at least one modulator, which is coupled to the output terminal of the MRR2, and modulates the filtered target carrier signal through the modulator to generate a modulated signal. Based on the number and bandwidth of subcarriers indicated in the control information 215, the signal modulation format and other information, the at least one modulator modulates the target carrier signal to generate a modulated signal 225.

[0071] In some embodiments of the present disclosure, at least one modulator is integrated with MRR1, MRR2 and SOA in the same module through photonic integrated circuit technology.

[0072] Small-sized, high-speed modulators compatible with silicon photonics technology developed using a hybrid integration route, such as hybrid silicon-organic modulators and plasma modulators, are suitable for the embodiments of the present disclosure. Therefore, the CSR module can be integrated with such modulators based on advanced PIC technology to construct a DSCM transmitter Tx integrated system.

[0073] Figure 4 1 shows a block diagram of an example communication system and its internal components in which embodiments of the present disclosure may be implemented. Figure 4 As shown, the Spoke device receives the frequency comb signal generated by the frequency comb generating device sent by the Hub device, and the Spoke device integrates the CSR module and the transmitter Tx of the modulator, processes and modulates the frequency comb signal based on the control information 215 to generate a modulated signal 225. The Spoke device sends the modulated signal to the Hub device, and the coherent receiver Rx on the Hub device receives the modulated signals uploaded by each Spoke device and combines them to form a DSCM signal.

[0074] Figure 5 FIG. 1 is a schematic diagram showing a CSR module and its internal components according to an embodiment of the present disclosure. Figure 5As shown, micro heaters H1 and H2 are respectively provided on MRR1 and MRR2, and photo detectors PD1 and PD2 are coupled to the output ports of MRR1 and MRR2. A part of the output optical signal of MRR1 and MRR2 is received by PD1 and PD2 respectively, and the input current of the micro heaters H1 and H2 on MRR1 and MRR2 is adjusted based on the signal strength of the part of the output signal to adjust the resonant wavelength of MRR1 and MRR2.

[0075] Two photodetectors PD1 and PD2 are coupled to the output ports of the first microring resonator and the second microring resonator. PD1 and PD2 are used to check the alignment of the transmit spectrum of MRR1 and MRR2 and the receive frequency comb. In the implementation, a very small part of the optical signal power output by MRR1 and MRR2 is injected into PD1 and PD2. By measuring the maximum power value after PD1 and PD2 when adjusting the temperature of microheaters H1 and H2, the desired target carrier signal can be accurately selected from the frequency comb signal.

[0076] In some embodiments of the present disclosure, Figure 5 As shown, Ic is the input current of the SOA, which is used to adjust the signal power (amplification factor) during the signal amplification process so that when the modulated signals 225 uploaded by each access device 110 are synthesized into a DSCM signal at the processing device 120, the power balance requirement between the modulated signals 225 is met.

[0077] The processing device 120 sends at least one carrier signal 205 through an optical fiber channel, for example. Due to the different transmission fiber lengths, it is necessary to control the output power of optical signals from different access devices 110 to maintain the power balance within the DSCM signal. This can be achieved by adjusting the input current of the SOA.

[0078] In some embodiments, the power of the target carrier signal is determined based on the transmission distance between the receiving device 110 and the processing device 120. For example, the processing device 120 performs ranging in the early stage of establishing a connection and records the signal transmission distance between the access device 110. Based on the transmission distance, the processing device 120 determines the power of the target carrier signal and writes it into the control information 215. The access device 110 amplifies the power of the target carrier signal 115 based on the control information 215.

[0079] In some embodiments of the present disclosure, the modulated signal obtained by modulating the target carrier signal by the modulator is located on one or both sides of the target carrier signal in the spectrum, that is, the target carrier signal is modulated so that the target carrier signal is at the edge of the subcarrier bandwidth of the DSCM signal.

[0080] Modulation is another important aspect of the DSCM scheme provided by the present disclosure. The bandwidth and number of subcarrier signals, as well as the modulation format of the subcarrier signals should be designed to balance spectrum efficiency and system performance. Figure 6 FIG. 1 is a schematic diagram showing the relationship between the carrier signal and the subcarrier signal in the frequency spectrum of an embodiment of the present disclosure. Figure 6 As shown, the subcarrier signal is placed at the edge of the target carrier signal (left figure) instead of at the center of the target carrier signal (right figure) to reduce the impact of residual amplifier noise generated by the downlink frequency comb, such as SOA noise and reflection noise.

[0081] In some embodiments of the present disclosure, before receiving at least one carrier signal 205 and control information 215, the access device 110 sends service requirement information of the access device 110 to the processing device 120, wherein the at least one carrier signal 205 and the control information 215 are determined based on the service requirement information.

[0082] Figure 7 A schematic diagram of the interaction process between the access device 110 and the processing device 120 of an embodiment of the present disclosure is shown. First, the access device 110 establishes a connection with the processing device 120. In some embodiments, the access device 110 and the processing device 120 establish a control channel of a preset frequency band. The access device 110 and the processing device 120 communicate using the control channel, and the access device 110 sends (720) information such as business requirements to the processing device 120, and the processing device 120 uses the control channel to query (730) business requests, synchronization information, and measurement of transmission distance. That is, before receiving at least one carrier signal 205 and control information 215, the access device 110 uses the control channel between the access device 110 and the processing device 120 to perform the activation (710) process of the access device 110.

[0083] After the connection is established, the processing device 120 sends at least one carrier signal 205 and control information 215 to the access device 110, and the at least one carrier signal 205 and the control information 215 are generated based on the service demand information. After receiving the service demand information, the processing device 120 allocates channels according to the service demand information of each access device 110, and determines (740) the target carrier signal position, the number and bandwidth of subcarrier signals, the modulation mode, the signal power, etc. corresponding to each access device 110. That is, the processing device 120 generates at least one carrier signal 205 and the control information 215 based on the service demand information. The processing device 120 can use a mode-locked laser to generate the required at least one carrier signal 205, for example, to generate a single optical carrier signal or a frequency comb signal, and send the one or more frequency comb signals and related allocation information (750) to the access device 110 to which it is connected.

[0084] The access device 110 adjusts (760) the CSR based on the control information 215, screens one or more carrier signals in the frequency comb, selects the frequency comb signal corresponding to the access device 110, and modulates (770) the corresponding carrier signal according to the allocated subcarrier bandwidth, modulation format and other information. The processing device 120 sends at least one carrier signal 205 and the control information 215 to the access device 110, wherein the control information 215 is sent through a control channel of a preset frequency band, and the control channel should be isolated from the frequency band of the allocated carrier signal in the spectrum. The control channel can be at least one digital subcarrier among multiple digital subcarriers in the communication spectrum between the access device 110 and the processing device 120, or the control channel can be at least one wavelength in the communication spectrum between the access device 110 and the processing device 120. After completing the modulation of the carrier signal, the access device 110 uses the subcarrier to send (780) a payload, and the processing device 120 receives (790) the payload and generates a DSCM signal.

[0085] Combine the following Fig. 8A , Figure 8B To describe several specific embodiments of the present disclosure. Fig. 8A FIG. 1 is a block diagram of an example communication system in which the embodiments of the present disclosure can upload and download signals and perform carrier allocation and modulation. Fig. 8A As shown, in the 5G ultra-high and 6G wireless communication backhaul (xhaul) system, the access point AP can be composed of different devices, such as a radio unit RU, or RU+distributed unit DU, or RU+DU+centralized unit CU. The corresponding data transmission between the AP and the central processing unit CPU is defined as fronthaul, midhaul, and backhaul, collectively referred to as xhaul. The CPU located in the central office CO receives and processes all data from different APs. The xhaul system in this embodiment consists of 4 APs (AP1, AP2, AP3, and AP4) and 1 CPU, which are connected by an optical fiber with a tree topology. In the downlink direction, the frequency comb generator (Freq.Comb Gen.) in the CPU generates two carriers with wavelengths of λ1 and λ2, with a frequency interval of 50 GHz. There are many ways to generate a frequency comb, one of which is to use a mode-locked laser. After transmission through the trunk optical fiber, the downlink carrier is coupled into 4 distributed optical fibers of different lengths.

[0086] In the AP, according to the service requirements and channel status information of the AP, the carrier selection repeater CSR and the modulation module described above are used to select and modulate the allocated carrier determined by the CPU. The structure of the CSR deployed in the AP is as described above. The free spectrum range FSR of the microring resonator MRR in the CSR is 45 GHz, which is compatible with the frequency interval of the downlink frequency comb. For an ordinary bandpass filter with only one passband, if you want to pick out another carrier instead of the previously used carrier (for example, select a carrier with a wavelength of λ2 instead of the previously used wavelength of λ1), a 50 GHz frequency shift should be performed. By using an MRR with multiple passbands, only 5 GHz of frequency shift is required to select a different carrier from CSR1 and CSR2 for CSR3 and CSR4, thereby reducing the delay and energy of the heating process in the MRR. When selecting a carrier in the CSR module, minimizing the difference between the FSR value and the frequency interval of the MRR is conducive to reducing the frequency shift.

[0087] However, on the other hand, widening the passband bandwidth of the MRR filter alleviates the difficulty of aligning the selected carrier with the MRR passband at the expense of greater insertion loss. Due to the different transmission fiber lengths, the output power of optical signals from different APs needs to be controlled to maintain the power balance within the DSCM signal. For example, AP1 is closer to the CPU (5km), while AP2 is farther away from the CPU (10km). The transmission distances of the carrier signals received by AP1 and AP2 are different, but AP1 and AP2 are assigned to the same carrier signal, and the subcarrier signals uploaded by them will be combined into the same DSCM signal for transmission. Therefore, the carrier signal needs to be processed at AP1 and / or AP2, and AP2 should amplify the carrier signal more to achieve balance with the carrier signal of AP1.

[0088] Figure 8B The schematic diagram shows the process of selecting the target carrier signal and modulating the subcarrier signal by the access device 110 according to the embodiment of the present disclosure. In this embodiment, the output power of AP2 and AP4 should be about 1 dB higher than the output power of AP1 and AP3. This can be achieved by adjusting the input current of the SOA. The AP modulates the screened target carrier signal to generate a subcarrier signal SC. The bandwidth, number, and position of the subcarrier signal SC on the spectrum are all determined by the CPU and included in the control information. Based on the control information, the AP modulates the allocated target carrier signal to generate a subcarrier signal SC. Figure 8B In this embodiment, AP1 and AP2 each occupy two subcarrier signals SC. And because AP3 and AP4 have different service requirements, they are allocated 1 and 3 subcarrier signals SC respectively.

[0089] In fact, the modulation format of AP1 and AP3 can be upgraded to a higher level of orthogonal amplitude modulation QAM, because their optical fiber transmission length is shorter, which improves the spectrum efficiency. That is, other modulation methods, or other combinations of the number of subcarrier signals, bandwidth, position of subcarrier signals on the spectrum, etc., can be used to implement the present disclosure. The output signals of the four APs are sent back to the CPU, where the signals from AP1 and AP2 are combined into a complete DSCM signal, and the signals from AP3 and AP4 are combined into another complete DSCM signal. In the CPU, coherent receivers (Coh.Rx) 1 and coherent receivers 2 are used to receive and process single DSCM signals of different wavelengths. In some other embodiments, one or more coherent receivers can be used to receive and process DSCM signals from APs.

[0090] The embodiments of the present disclosure propose a digital subcarrier multiplexing scheme based on the carrier signal sent by the Hub. Since the transmitting module in the AP only selects and amplifies the carrier in the frequency comb from the same Hub, the collision of signals from different APs in the frequency domain is avoided. The effective data transmission performance using DSCM is improved, and it can be used in multi-wavelength systems to meet the capacity requirements of the next generation optical metropolitan area / access network exceeding Tb / s. In addition, in some embodiments of the present disclosure, although a point-to-multipoint tree topology communication system is used for illustration, these communication systems are only schematic, and those skilled in the art can easily understand that any communication system applicable to multi-point uplink DSCM signals, such as a ring system, a star system, a grid system, etc., can be applicable to the embodiments of the present disclosure, and these embodiments are also within the scope of the present disclosure.

[0091] In some embodiments of the present disclosure, the access device 110 sends valid information to the processing device 120 using a subcarrier signal until the communication demand at the access device 110 changes, at which time the access device 110 resends the service demand information to the processing device 120 .

[0092] The access device 110 selects the target carrier signal according to the control information, modulates the modulated signal, uses the modulated signal to send valid information to the processing device 120, and starts normal communication between the access device 110 and the processing device 120 until the service demand of the access device 110 changes. The access device 110 resends the service demand information to the processing device 120, and the processing device 120 implements ranging, synchronization, querying service demand and other operations, and allocates the carrier signal and control information according to the channel situation and service demand information, and sends them to the access device 110.

[0093] In some embodiments of the present disclosure, the processing device 120 and the access device 110 can communicate through a control channel, and the frequency band of the control channel may be different from the frequency band of the carrier signal. More specifically, the access device 110 may send communication demand information via the control channel, the access device 110 may receive control information sent by the processing device 120 via the control channel, and / or the processing device 120 may measure the signal transmission distance via the control channel. In some examples, the access device 110 may connect to the processing device 120 using the control channel. After the connection is established, the processing device 120 implements general operations such as ranging, synchronization, and querying service requirements. During the activation of the control channel, communication between the access device 110 and the processing device 120 may be difficult, so in some embodiments, a specific subcarrier frequency band or wavelength is reserved as a control channel.

[0094] Fig. 9 FIG. 1 is a schematic diagram of a process flow executed by the access device 110 according to some embodiments of the present disclosure. Figure 1A To describe Fig. 9 900. In block 910, the access device 110 receives at least one carrier signal and control information from the processing device 120. In block 920, based on the control information, the access device 110 processes a target carrier signal in the at least one carrier signal. In block 930, based on the control information, the access device 110 modulates the target carrier signal to generate a modulated signal, wherein the modulated signal and another modulated signal of one or more other access devices will be combined at the processing device 120 to form a digital subcarrier modulation (DSCM) signal. In block 940, the access device 110 sends the modulated signal to the processing device 120.

[0095] In some embodiments, the access device 110 processes the target carrier signal in the following manner: based on the signal power information indicated in the control information, using at least one semiconductor optical amplifier (SOA) to amplify the target carrier signal; and using a microring resonator (MRR) to filter out amplified spontaneous emission (ASE) noise introduced by at least one SOA.

[0096] In some embodiments, where at least one carrier signal includes multiple carrier signals and the MRR is a second MRR, the access device 110 also uses the first MRR to select a target carrier signal from the multiple carrier signals based on the frequency position of the target carrier signal indicated in the control information.

[0097] In some embodiments, the access device 110 uses the first MRR by heating a waveguide of the first MRR to move a passband of a plurality of passbands of the first MRR to a frequency position of a target carrier signal.

[0098] In some embodiments, the access device 110 uses the at least one SOA in the following manner: adjusting an input current of the at least one SOA based on the signal power information indicated in the control information.

[0099] In some embodiments, the second MRR is a replica of the first MRR, and the second MRR is subjected to temperature control similar to that of the first MRR so as to move a passband of the plurality of passbands of the second MRR to a frequency position of a target carrier signal.

[0100] In some embodiments, a micro heater is disposed on the first MRR and the second MRR; or a photodetector (PD) is coupled to the output ports of the first MRR and the second MRR.

[0101] In some embodiments, the first MRR, the SOA, and the second MRR are integrated in a single module based on photonic integrated circuit (PIC) technology.

[0102] In some embodiments, at least one of the modulators is integrated into the single module based on PIC technology.

[0103] In some embodiments, the target carrier signal is modulated so that the target carrier signal is at the edge of the sub-carrier bandwidth of the DSCM signal.

[0104] In some embodiments, before receiving at least one carrier signal and control information, the access device 110 sends service requirement information of the access device 110 to the processing device 120, wherein the at least one carrier signal and the control information are determined based on the service requirement information.

[0105] In some embodiments, the access device 110 performs an activation process of the access device 110 using a control channel between the access device 110 and the processing device 120 before receiving the at least one carrier signal and the control information.

[0106] In some embodiments, at least one of the following is configured as a control channel: at least one digital subcarrier among a plurality of digital subcarriers in a communication spectrum between the access device 110 and the processing device 120; or at least one wavelength in the communication spectrum.

[0107] In some embodiments, at least one carrier signal includes a frequency comb signal, and the control information includes one or more of the following: the position of the target carrier on the spectrum, the number of subcarriers used for access device 110, the bandwidth of the subcarriers, the signal modulation format used for access device 110, or the subcarrier signal power used for access device 110.

[0108] In some embodiments, a free spectral range (FSR) of the first MRR is determined based on a frequency spacing of the frequency comb signal.

[0109] In some embodiments, the number of subcarriers, the bandwidth of the subcarriers, and the modulation format are determined based on spectral efficiency and system performance.

[0110] Fig.10 FIG. 1 is a flow chart showing a process executed by the processing device 120 according to some embodiments of the present disclosure. Figure 1A To describe Fig.10 1000. In block 1010, the processing device 120 determines at least one carrier signal and control information for the access device 110. In block 1020, the processing device 120 sends the at least one carrier signal and the control information to the access device 110. In block 1030, a modulated signal is received from the access device 110, wherein the modulated signal is generated by modulating a target carrier signal in the at least one carrier signal based on the control information, and wherein the modulated signal is combined with another modulated signal of one or more other access devices 110 at the processing device 120 to form a digital subcarrier modulation (DSCM) signal.

[0111] In some embodiments, the processing device 120 determines at least one carrier signal and control information by: receiving service demand information of the access device 110 from the access device 110; and determining at least one carrier signal and control information based on the received service demand information and channel state information associated with the access device 110.

[0112] In some embodiments, the processing device 120 performs an activation process of the access device 110 using a control channel between the processing device 120 and the access device 110 before determining the at least one carrier signal and the control information.

[0113] In some embodiments, at least one of the following is configured as a control channel: at least one digital subcarrier among a plurality of digital subcarriers in a communication spectrum between the processing device 120 and the access device 110; or at least one wavelength in the communication spectrum.

[0114] In some embodiments, the processing device 120 receives a plurality of DSCM signals from a plurality of access devices 110 using one or more coherent receivers; and processes the plurality of DSCM signals using the one or more coherent receivers.

[0115] In some embodiments, the target carrier signal is at the edge of the sub-carrier bandwidth of the DSCM signal.

[0116] In some embodiments, at least one carrier signal includes a frequency comb signal, and the control information includes one or more of the following: the position of the target carrier on the spectrum, the number of subcarriers used for access device 110, the bandwidth of the subcarriers, the signal modulation format used for access device 110, or the subcarrier signal power used for access device 110.

[0117] In some embodiments, the number of subcarriers, the bandwidth of the subcarriers, and the modulation format are determined based on spectral efficiency and system performance.

[0118] In some example embodiments, an apparatus capable of executing method 900 (e.g., access device 110) may include a component for executing each step of method 900. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit or a software module.

[0119] The apparatus includes: a component for receiving at least one carrier signal and control information from a processing device at an access device; a component for processing a target carrier signal in at least one carrier signal based on the control information; a component for modulating the target carrier signal based on the control information to generate a modulated signal, wherein the modulated signal and another modulated signal of another one or more access devices will be combined at the processing device to form a digital subcarrier modulation (DSCM) signal; and a component for sending the modulated signal to the processing device.

[0120] In some embodiments, the components for processing the target carrier signal include: components for amplifying the target carrier signal using at least one semiconductor optical amplifier (SOA) based on signal power information indicated in the control information; and components for filtering out amplified spontaneous emission (ASE) noise introduced by at least one SOA using a microring resonator (MRR).

[0121] In some embodiments, wherein at least one carrier signal includes multiple carrier signals, the MRR is a second MRR, and the apparatus further comprises: a component for selecting a target carrier signal from the multiple carrier signals using the first MRR based on the frequency position of the target carrier signal indicated in the control information.

[0122] In some embodiments, the means for using the first MRR includes means for heating a waveguide of the first MRR to move a passband of the plurality of passbands of the first MRR to a frequency position of a target carrier signal.

[0123] In some embodiments, means for using at least one SOA includes means for adjusting an input current of the at least one SOA based on the signal power information indicated in the control information.

[0124] In some embodiments, the second MRR is a replica of the first MRR, and the second MRR is subjected to temperature control similar to that of the first MRR so as to move a passband of the plurality of passbands of the second MRR to a frequency position of a target carrier signal.

[0125] In some embodiments, a micro heater is disposed on the first MRR and the second MRR; or a photodetector (PD) is coupled to the output ports of the first MRR and the second MRR.

[0126] In some embodiments, the first MRR, the SOA, and the second MRR are integrated in a single module based on photonic integrated circuit (PIC) technology.

[0127] In some embodiments, at least one modulator is integrated in the single module based on PIC technology.

[0128] In some embodiments, the target carrier signal is modulated so that the target carrier signal is at the edge of the sub-carrier bandwidth of the DSCM signal.

[0129] In some embodiments, the apparatus further comprises: a component for sending service requirement information of the access device to the processing device before receiving the at least one carrier signal and the control information, wherein the at least one carrier signal and the control information are determined based on the service requirement information.

[0130] In some embodiments, the apparatus further comprises: means for performing an activation procedure of the access device using a control channel between the access device and the processing device before receiving the at least one carrier signal and the control information.

[0131] In some embodiments, at least one of the following is configured as a control channel: at least one digital subcarrier among a plurality of digital subcarriers in a communication spectrum between the access device and the processing device; or at least one wavelength in the communication spectrum.

[0132] In some embodiments, at least one carrier signal includes a frequency comb signal, and the control information includes one or more of the following: the position of the target carrier on the spectrum, the number of subcarriers used for access devices, the bandwidth of the subcarriers, the signal modulation format used for access devices, or the subcarrier signal power used for access devices.

[0133] In some embodiments, a free spectral range (FSR) of the first MRR is determined based on a frequency spacing of the frequency comb signal.

[0134] In some embodiments, the number of subcarriers, the bandwidth of the subcarriers, and the modulation format are determined based on spectral efficiency and system performance.

[0135] In some example embodiments, an apparatus capable of performing method 1000 (e.g., computing device 120) may include a component for performing the various steps of method 1000. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit or a software module.

[0136] The apparatus includes: a component for determining at least one carrier signal and control information for an access device at a processing device; a component for sending at least one carrier signal and control information to the access device; and a component for receiving a modulated signal from the access device, wherein the modulated signal is generated by modulating a target carrier signal in at least one carrier signal based on the control information, and wherein the modulated signal is combined with another modulated signal of one or more other access devices at the processing device to form a digital subcarrier modulation (DSCM) signal.

[0137] In some embodiments, the component for determining at least one carrier signal and control information includes: a component for receiving access device service demand information from an access device; and a component for determining at least one carrier signal and control information based on the received service demand information and channel state information associated with the access device.

[0138] In some embodiments, the apparatus further comprises: means for performing an activation procedure of the access device using a control channel between the processing device and the access device before determining the at least one carrier signal and the control information.

[0139] In some embodiments, at least one of the following is configured as a control channel: at least one digital subcarrier among a plurality of digital subcarriers in a communication spectrum between the processing device and the access device; or at least one wavelength in the communication spectrum.

[0140] In some embodiments, the apparatus further comprises: means for receiving a plurality of DSCM signals from a plurality of access devices using one or more coherent receivers; and means for processing the plurality of DSCM signals using the one or more coherent receivers.

[0141] In some embodiments, the target carrier signal is at the edge of the sub-carrier bandwidth of the DSCM signal.

[0142] In some embodiments, at least one carrier signal includes a frequency comb signal, and the control information includes one or more of the following: the position of the target carrier on the spectrum, the number of subcarriers used for access devices, the bandwidth of the subcarriers, the signal modulation format used for access devices, or the subcarrier signal power used for access devices.

[0143] In some embodiments, the number of subcarriers, the bandwidth of the subcarriers, and the modulation format are determined based on spectral efficiency and system performance.

[0144] Fig.11 1 is a simplified block diagram of an electronic device 1100 suitable for implementing an embodiment of the present disclosure. The device 1100 may be provided to implement an access device or a processing device, such as Figure 1A An access device 110 or a processing device 120 is shown. As shown, the device 1100 includes one or more processors 1110, one or more memories 1120 coupled to the processor 1110, and one or more communication modules 1140 coupled to the processor 1110.

[0145] The communication module 1140 is used for two-way communication. For example, the communication module 1140 may include a transmitter, a receiver, or a transceiver used in the embodiments of the present disclosure. The communication interface may represent any interface necessary for communicating with other network elements.

[0146] Processor 1110 may be of any type suitable for the local technology network and may include, but is not limited to, one or more of a general purpose computer, a special purpose computer, a microcontroller, a digital signal controller (DSP), and a controller-based multi-core controller architecture. Device 1100 may have multiple processors, such as application specific integrated circuit chips, which are time-slaved to a clock synchronized with a main processor.

[0147] The memory 1120 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 1124, erasable programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), and other magnetic storage and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 1122 and other volatile memories that do not persist over the duration of a power outage.

[0148] Computer program 1130 includes computer executable instructions executed by associated processor 1110. Program 1130 may be stored in ROM 1120. Processor 1110 may perform any suitable actions and processes by loading program 1130 into RAM 1122.

[0149] The embodiments of the present disclosure can be implemented with the help of program 1130, so that the device 1100 can execute the Figure 2 Any process of the present disclosure discussed. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0150] In some embodiments, the program 1130 may be tangibly embodied in a computer-readable medium that may be included in the device 1100 (such as in the memory 1120) or other storage device accessible by the device 1100. The program 730 may be loaded from the computer-readable medium to the RAM 1122 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc.

[0151] Fig.12 An example of a computer readable medium 1200 in the form of a CD or DVD is shown. The computer readable medium has a program 1130 stored thereon.

[0152] In general, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be performed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flow charts, or using some other graphical representation, it should be understood that the blocks, devices, systems, techniques, or methods described herein may be implemented as, by way of non-limiting example, hardware, software, firmware, dedicated circuits or logic, general purpose hardware or a controller or other computing device, or some combination thereof.

[0153] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer executable instructions, such as instructions included in a program module, which are executed in a device on a real or virtual processor of a target to perform the above-referenced Figures 9 and 10 Methods 900, 1000. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of program modules can be combined or divided between program modules as needed. Machine executable instructions for program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in local and remote storage media.

[0154] The computer program code for realizing the method of the present disclosure can be written in one or more programming languages. These computer program codes can be provided to the processor of general-purpose computer, special-purpose computer or other programmable data processing device, so that the program code, when being executed by computer or other programmable data processing device, causes the function / operation specified in flow chart and / or block diagram to be implemented. The program code can be executed completely on computer, partly on computer, as independent software package, partly on computer and partly on remote computer or completely on remote computer or server.

[0155] In the context of the present disclosure, computer program codes or related data may be carried by any appropriate carrier to enable a device, apparatus or processor to perform the various processes and operations described above. Examples of carriers include signals, computer readable media, and the like. Examples of signals may include electrical, optical, radio, acoustic or other forms of propagation signals, such as carrier waves, infrared signals, and the like.

[0156] A computer-readable medium may be any tangible medium containing or storing a program for or about an instruction execution system, device or equipment. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared or semiconductor system, device or equipment, or any suitable combination thereof. A more detailed example of a computer-readable storage medium includes an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical storage device, a magnetic storage device, or any suitable combination thereof. As used herein, the term "non-transient" or "non-transient" is a limitation on the medium itself (i.e., tangible, not a signal), rather than a limitation on the persistence of data storage (e.g., RAM and ROM).

[0157] In addition, although the operation of the method of the present disclosure is described in a particular order in the accompanying drawings, this does not require or imply that these operations must be performed in this particular order, or that all the operations shown must be performed to achieve the desired result. On the contrary, the steps depicted in the flow chart can change the order of execution. Additionally or alternatively, some steps can be omitted, multiple steps can be combined into one step for execution, and / or one step can be decomposed into multiple steps for execution. It should also be noted that the features and functions of two or more devices according to the present disclosure can be embodied in one device. Conversely, the features and functions of a device described above can be further divided into being embodied by multiple devices.

[0158] Although the present disclosure has been described with reference to several specific embodiments, it should be understood that the present disclosure is not limited to the specific embodiments disclosed. The present disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0159] In addition, although the operation of the method of the present disclosure is described in a particular order in the accompanying drawings, this does not require or imply that these operations must be performed in this particular order, or that all the operations shown must be performed to achieve the desired result. On the contrary, the steps depicted in the flow chart can change the order of execution. Additionally or alternatively, some steps can be omitted, multiple steps can be combined into one step for execution, and / or one step can be decomposed into multiple steps for execution. It should also be noted that the features and functions of two or more devices according to the present disclosure can be embodied in one device. Conversely, the features and functions of a device described above can be further divided into being embodied by multiple devices.

[0160] Although the present disclosure has been described with reference to several specific embodiments, it should be understood that the present disclosure is not limited to the specific embodiments disclosed. The present disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. An access device, comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the access device to at least: receiving at least one carrier signal and control information from a processing device; Based on the control information, processing a target carrier signal in the at least one carrier signal; modulating the target carrier signal based on the control information to generate a modulated signal, wherein the modulated signal and another modulated signal of one or more other access devices are combined at the processing device to form a digital subcarrier modulation (DSCM) signal; and The modulated signal is sent to the processing device.

2. The access device according to claim 1, wherein the access device is configured to process the target carrier signal by: amplifying the target carrier signal using at least one semiconductor optical amplifier (SOA) based on the signal power information indicated in the control information; and A microring resonator (MRR) is used to filter out amplified spontaneous emission (ASE) noise introduced by the at least one SOA.

3. The access device according to claim 2, wherein the at least one carrier signal comprises a plurality of carrier signals, the MRR is a second MRR, and the access device is further configured to: The target carrier signal is selected from the plurality of carrier signals using a first MRR based on a frequency position of the target carrier signal indicated in the control information.

4. The access device of claim 3, wherein the access device is caused to use the first MRR by: The waveguide of the first MRR is heated to shift a passband of a plurality of passbands of the first MRR to the frequency position of the target carrier signal.

5. The access device according to any one of claims 2 to 4, wherein the access device is caused to use the at least one SOA by: Based on the signal power information indicated in the control information, an input current of the at least one SOA is adjusted.

6. An access device according to any one of claims 2-5, wherein the second MRR is a replica device of the first MRR, and the second MRR is subjected to temperature control similar to that of the first MRR so as to move the passbands of multiple passbands of the second MRR to the frequency position of the target carrier signal.

7. The access device according to any one of claims 2 to 6, wherein at least one of the following items is provided: A micro heater is disposed on the first MRR and the second MRR; or Photodetectors (PDs) are coupled to output ports of the first MRR and the second MRR.

8. The access device according to any one of claims 3-6, wherein the first MRR, the SOA and the second MRR are integrated into a single module based on photonic integrated circuit (PIC) technology.

9. The access device according to claim 8, wherein at least one modulator is integrated in the single module based on the PIC technology.

10. The access device according to any one of claims 1-9, wherein the target carrier signal is modulated so that the target carrier signal is at the edge of the subcarrier bandwidth of the DSCM signal.

11. The access device according to any one of claims 1 to 10, wherein the access device is further configured to: Before receiving the at least one carrier signal and the control information, the service requirement information of the access device is sent to the processing device, wherein the at least one carrier signal and the control information are determined based on the service requirement information.

12. The access device according to any one of claims 1 to 11, wherein the access device is further configured to: Prior to receiving the at least one carrier signal and the control information, an activation procedure of the access device is performed using a control channel between the access device and the processing device.

13. The access device according to claim 12, wherein at least one of the following is configured as the control channel: At least one digital subcarrier among a plurality of digital subcarriers in a communication spectrum between the access device and the processing device; or At least one wavelength in the communications spectrum.

14. An access device according to any one of claims 1-13, wherein the at least one carrier signal includes a frequency comb signal, and the control information includes one or more of the following: the position of the target carrier on the spectrum, the number of subcarriers used for the access device, the bandwidth of the subcarriers, the signal modulation format used for the access device, or the subcarrier signal power used for the access device.

15. The access device of claim 14, wherein a free spectral range (FSR) of the first MRR is determined based on a frequency spacing of the frequency comb signal.

16. The access device according to claim 14 or 15, wherein the number of the subcarriers, the bandwidth of the subcarriers and the modulation format are determined based on spectrum efficiency and system performance.

17. A processing device comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the processing device to at least: Determining at least one carrier signal and control information for an access device; Sending the at least one carrier signal and the control information to the access device; as well as A modulated signal is received from the access device, wherein the modulated signal is generated by modulating a target carrier signal among the at least one carrier signal based on the control information, and wherein the modulated signal is combined with another modulated signal of one or more other access devices at the processing device to form a digital subcarrier modulation (DSCM) signal.

18. The processing device according to claim 17, wherein the processing device is caused to determine the at least one carrier signal and the control information by: receiving service demand information of the access device from the access device; and The at least one carrier signal and the control information are determined based on the received service demand information and channel state information associated with the access device.

19. The processing device according to claim 17 or 18, wherein the processing device is further caused to: Before determining the at least one carrier signal and the control information, an activation process of the access device is performed using a control channel between the processing device and the access device.

20. The processing device according to claim 19, wherein at least one of the following is configured as the control channel: At least one digital subcarrier among a plurality of digital subcarriers in a communication spectrum between the processing device and the access device; or At least one wavelength in the communications spectrum.

21. The processing device according to any one of claims 17 to 20, wherein the processing device is further caused to: receiving a plurality of DSCM signals from a plurality of access devices using one or more coherent receivers; and The plurality of DSCM signals are processed using the one or more coherent receivers.

22. The processing device according to any one of claims 17-21, wherein the target carrier signal is at the edge of the sub-carrier bandwidth of the DSCM signal.

23. A processing device according to any one of claims 17-22, wherein the at least one carrier signal includes a frequency comb signal, and the control information includes one or more of the following: the position of the target carrier on the spectrum, the number of subcarriers used for the access device, the bandwidth of the subcarriers, the signal modulation format used for the access device, or the subcarrier signal power used for the access device.

24. The processing device of claim 23, wherein the number of the subcarriers, the bandwidth of the subcarriers, and the modulation format are determined based on spectral efficiency and system performance.

25. A method comprising: At the access device, receiving at least one carrier signal and control information from a processing device; Based on the control information, processing a target carrier signal in the at least one carrier signal; modulating the target carrier signal based on the control information to generate a modulated signal, wherein the modulated signal and another modulated signal of one or more other access devices are combined at the processing device to form a digital subcarrier modulation (DSCM) signal; and The modulated signal is sent to the processing device.

26. A method comprising: At a processing device, determining at least one carrier signal and control information for an access device; Sending the at least one carrier signal and the control information to the access device; as well as A modulated signal is received from the access device, wherein the modulated signal is generated by modulating a target carrier signal among the at least one carrier signal based on the control information, and wherein the modulated signal is combined with another modulated signal of one or more other access devices at the processing device to form a digital subcarrier modulation (DSCM) signal.

27. An apparatus comprising: means for receiving, at the access device, at least one carrier signal and control information from the processing device; A component for processing a target carrier signal in the at least one carrier signal based on the control information; means for modulating the target carrier signal based on the control information to generate a modulated signal, wherein the modulated signal and further modulated signals of further one or more access devices are to be combined at the processing device to form a digital subcarrier modulation (DSCM) signal; and Means for sending said modulated signal to said processing device.

28. An apparatus comprising: means for determining, at a processing device, at least one carrier signal and control information for an access device; A component for sending the at least one carrier signal and the control information to the access device; as well as A component for receiving a modulated signal from the access device, wherein the modulated signal is generated by modulating a target carrier signal among the at least one carrier signal based on the control information, and wherein the modulated signal is combined with another modulated signal of one or more other access devices at the processing device to form a digital subcarrier modulation (DSCM) signal.

29. A computer-readable medium having instructions stored thereon, which, when executed by at least one processing unit, causes the at least one processing unit to be configured to perform the method according to claim 25 or 26.

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