Transmitting device, receiving device, and control method

Abstract

A transmission device according to one aspect of the present invention is provided with: a first modulation unit for performing intensity modulation on a control signal for use in communication management control; a second modulation unit for performing frequency modulation or phase modulation on the control signal; a reception modulation method acquisition unit for acquiring a modulation method with which a reception device for receiving the control signal can receive the control signal; and a modulation control unit for performing modulation on the control signal by the first modulation unit or the second modulation unit in accordance with the modulation method acquired by the reception modulation method acquisition unit.

Description

[Technical field]

[0001] The present invention relates to a transmitting device, a receiving device, and a control method. [Background technology]

[0002] There is an IOWN (Innovative Optical and Wireless Network) that eliminates photoelectric conversion and electrical routing processing as much as possible. Figure 30 is a configuration diagram of this IOWN. User devices in the APN (All-Photonics Network) of the IOWN shown in Figure 30 communicate using wavelengths and routes assigned to an APN controller connected to a Ph-GW.

[0003] Wavelengths and route information are exchanged using a control signal channel called an auxiliary management and control channel (AMCC) when communication with the user equipment begins. At the start of communication, the AMCC transceiver located in the user equipment and the Ph-GW communicates and connects to any communication destination.

[0004] AMCC may be used not only for communication with the nearest Ph-GW but also for control signal exchange between AMCC-compatible user equipment. AMCC between AMCC-compatible user equipment may be used to transmit and receive control signals such as network control information and communication wavelength configuration. AMCC may also be used to transmit and receive control information between devices that provide services to user equipment.

[0005] In currently envisioned user equipment, as shown in Fig. 31, a configuration is considered in which light emitted from a light source is modulated using a signal in which a user signal DATA and an AMCC signal DATA_AMCC are superimposed by an intensity modulator such as an EA modulator (see Non-Patent Document 1). At this time, the frequency of the AMCC signal is superimposed on a frequency band that has little effect on the user signal.

[0006] For example, as shown in Fig. 32, the AMCC signal is superimposed on the low frequency side. In the configuration shown in Fig. 31, the AMCC signal is superimposed by intensity modulation, so that the AMCC signal can be demodulated using a simple optical receiver on the receiver side of the Ph-GW or user equipment. On the other hand, because it uses intensity modulation, the AMCC signal flowing on the communication path can be easily acquired by inserting a simple receiver on the path.

[0007] Figures 33 and 34 are diagrams showing configuration examples in which a coherent transceiver using phase modulation is used for a user device. In this configuration, as shown in Figure 33, a user signal is treated as a phase-modulated signal, and an AMCC signal is applied using an external intensity modulator, and a receiver for intensity modulation is used on the receiving side (see Non-Patent Document 2). In this case, it is assumed that the external intensity modulator will be, for example, an SOA (Semiconductor Optical Amplifier).

[0008] Alternatively, as shown in Fig. 34, a configuration may be considered in which the phase and intensity are modulated simultaneously by an IQ modulator, and the user signal is transmitted as a phase-modulated signal and the AMCC signal is transmitted as an intensity-modulated signal, as described above. In this case, a configuration may be considered in which the user signal and the AMCC signal are demodulated by a digital signal processing circuit section of a coherent receiver.

[0009] Furthermore, as shown in Fig. 35, a configuration is conceivable in which frequency modulation is applied by utilizing the frequency chirp associated with the bias current modulation of a direct modulation diode (Non-Patent Document 3). In this case, the AMCC signal is superimposed not only on the frequency modulation component but also on the intensity modulation component associated with the bias current modulation. Therefore, the AMCC signal component can be demodulated by both the coherent receiver and the intensity modulation optical receiver. [Prior art documents] [Non-patent literature]

[0010] [Non-Patent Document 1] Y. Tanaka, T. Kanai, K. Hara, M. Chen, K. Honda, T. Shindo, Y. Senoo, S. Kaneko, H. Nakamura, J. Kani, K. Sano, and T. Yoshida, "High-power-budget End-to-end Optical Connection with AMCC Superposition of SOA-integrated EA-DFB Transmitter in All-Photonics Network," in 26th Optoelectronics and Communications Conference, P. Alexander Wai, H. Tam, and C. Yu, eds., OSA Technical Digest (Optical Society of America, 2021), paper M4A.7. [Non-Patent Document 2] R. Igarashi, R. Koma, K. Hara, K. Honda, J. -i. Kani and T. Yoshida, “Simultaneous Reception of ASK-based AMCC Signals and QPSK Signals with Single Coherent Receiver,” 2021 Optical Fiber Communications Conference and Exhibition (OFC), 2021, pp. 1-3. [Non-Patent Document 3] M. Fujiwara et al., “Performance Evaluation of CPFSK Transmitters for TDM-Based Digital Coherent PON Upstream,” in Proc. OFC2017, Th1K.5, Los Angeles, USA, 2017. Summary of the Invention [Problem to be solved by the invention]

[0011] Thus, there are various modulation methods for AMCC signals.

[0012] In view of the above circumstances, an object of the present invention is to provide a technique that is compatible with the modulation method of the AMCC signal of the communication destination. [Means for solving the problem]

[0013] One aspect of the present invention is a transmitting device comprising a first modulation unit that intensity-modulates a control signal for managing and controlling communications, a second modulation unit that phase-modulates or frequency-modulates the control signal, a receiving modulation scheme acquisition unit that acquires a modulation scheme receivable by a receiving device that receives the control signal, and a modulation control unit that modulates the control signal by the first modulation unit or the second modulation unit depending on the modulation scheme acquired by the receiving modulation scheme acquisition unit.

[0014] One aspect of the present invention is a receiving device comprising: a receiving unit that receives a control signal for performing management control of communications; a first demodulation unit that demodulates an intensity-modulated signal; a second demodulation unit that demodulates a phase-modulated or frequency-modulated signal; a duplication unit that copies the control signal received by the receiving unit and outputs it to the first demodulation unit and the second demodulation unit; a transmission modulation scheme acquisition unit that acquires a modulation scheme by which the control signal is modulated by a transmitting device that transmits the control signal; and a demodulation control unit that demodulates the control signal in the first demodulation unit or the second demodulation unit depending on the modulation scheme acquired by the transmission modulation scheme acquisition unit.

[0015] One aspect of the present invention is a receiving device comprising a receiving unit that receives a control signal for performing management control of communications, a first demodulation unit that demodulates an intensity-modulated signal, a second demodulation unit that demodulates a phase-modulated or frequency-modulated signal, and a signal detection unit that detects the modulation method of the control signal received by the receiving unit and demodulates the control signal by the first demodulation unit or the second demodulation unit depending on the detected modulation method.

[0016] One aspect of the present invention is a control method for a transmitting device that transmits a control signal for managing and controlling communications, the control method comprising: a receiving modulation method acquisition step of acquiring a modulation method receivable by a receiving device that receives the control signal; and a modulation control step of intensity modulating, phase modulating, or frequency modulating the control signal according to the modulation method acquired by the receiving modulation method acquisition step.

[0017] One aspect of the present invention is a control method for a receiving device that receives a control signal for managing and controlling communications, the control method comprising: a transmission modulation method acquisition step of acquiring a modulation method by which the control signal is modulated by a transmitting device that transmits the control signal; and a modulation control step of demodulating the control signal as an intensity-modulated signal or as a phase-modulated or frequency-modulated signal, depending on the modulation method acquired in the transmission modulation method acquisition step. Effect of the Invention

[0018] The present invention makes it possible to accommodate the AMCC signal modulation method of the communication destination. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a configuration diagram showing a communication system using CPFSK. [Diagram 2] FIG. 1 illustrates a first example of a configuration of a transmitting device. [Diagram 3] FIG. 13 is a diagram illustrating an embodiment in modulation method A. [Figure 4] FIG. 13 is a diagram illustrating an embodiment in modulation method A. [Diagram 5] FIG. 13 is a diagram showing an embodiment in modulation scheme AB. [Figure 6] FIG. 13 is a diagram showing an embodiment in modulation scheme AB. [Figure 7] FIG. 13 is a diagram illustrating an embodiment in modulation method B. [Figure 8] FIG. 13 is a diagram illustrating an embodiment in modulation method B. [Figure 9] 11 is a flowchart showing a process flow in the first configuration example of the transmitting device. [Figure 10] FIG. 1 is a diagram showing an embodiment of point-to-multipoint communication. [Figure 11] FIG. 11 illustrates a second configuration example of a transmitting device. [Figure 12] FIG. 13 is a diagram illustrating an embodiment in modulation method A. [Figure 13] FIG. 13 is a diagram showing an embodiment in modulation scheme AB. [Figure 14] FIG. 13 is a diagram illustrating an embodiment in modulation method B. [Figure 15] FIG. 2 is a diagram showing an example of an amplification band of an SOA. [Figure 16] FIG. 13 is a diagram illustrating an embodiment in modulation method A. [Figure 17] FIG. 13 is a diagram showing an embodiment in modulation scheme AB. [Figure 18] FIG. 13 is a diagram illustrating an embodiment in modulation method B. [Figure 19] FIG. 1 is a diagram showing an embodiment of point-to-multipoint communication. [Figure 20] FIG. 1 is a diagram illustrating an example of the configuration of a user device including a transmitting device. [Figure 21] FIG. 1 is a diagram illustrating an example of the configuration of a user device including a transmitting device. [Figure 22] FIG. 2 is a diagram illustrating an example of the configuration of a receiving device. [Diagram 23] FIG. 2 is a diagram illustrating an example of the configuration of a receiving side DSP. [Figure 24] FIG. 2 is a diagram illustrating an example of the configuration of a receiving side DSP. [Diagram 25] 13 is a flowchart showing a process flow in configuration example 2 of the receiving DSP. [Figure 26] FIG. 2 is a diagram illustrating an example of the configuration of a receiving side DSP. [Figure 27] 13 is a flowchart showing a process flow in configuration example 3 of a receiving DSP. [Figure 28] FIG. 11 is a configuration diagram for explaining a process at the time of initial connection. [Figure 29] FIG. 13 is a sequence diagram showing an initial connection. [Diagram 30] This is a diagram of the IOWN configuration. [Diagram 31] 11 is a diagram for explaining the use of a signal in which a user signal DATA and an AMCC signal DATA_AMCC are superimposed. FIG. [Diagram 32] FIG. 13 is a diagram showing an AMCC signal being superimposed on the low frequency side. [Diagram 33] FIG. 11 is a diagram illustrating a configuration example in which a phase-modulated coherent transceiver is used in a user device. [Diagram 34] FIG. 11 is a diagram illustrating a configuration example in which a phase-modulated coherent transceiver is used in a user device. [Diagram 35] FIG. 1 is a diagram showing a configuration for applying frequency modulation using frequency chirp. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings. 1 is a configuration diagram showing a communication system 1 using continuous phase FSK (CPFSK). The communication system 1 is composed of an APN (All-Photonics Network) controller 10, AMCC receivers 20-1, 20-2, Ph-GWs 30-1, 30-2, and a user device 100. When there is no particular distinction between the AMCC receivers 20-1, 20-2, they are expressed as an AMCC receiver 20. When there is no particular distinction between the Ph-GWs 30-1, 30-2, they are expressed as a Ph-GW 30. Ph-GW is an abbreviation of Photonic GW.

[0021] The user equipment 100 is connected to the Ph-GW 30. The Ph-GW 30 is connected to the AMCC receiver 20. The AMCC receiver 20 is connected to the APN controller 10. In the configuration shown in Fig. 1, when starting communication, the user equipment 100 exchanges control signals for managing and controlling communication with the APN controller 10 using an auxiliary management and control channel (AMCC), thereby setting wavelengths to be used in communication, etc. At this time, the Ph-GW 30 sets a route to the APN controller 10 so that the user equipment 100 can communicate.

[0022] The APN controller 10 and the Ph-GW 30 have five main functions. The first is a wavelength control and monitoring function that specifies and controls which wavelength the user device 100 uses and monitors the wavelength of the signal. The second is a pass and stop function that passes signals according to the opening of a path and stops unnecessary signals. The third is a function that concentrates optical signals of the wavelength set in each user device and transfers them to the trunk network, and a concentrating and distributing function that distributes optical signals transferred from the trunk network according to each wavelength. The fourth is a turn-back function that enables traffic that requires the shortest route to be turned back at the Ph-GW 30 where the optical signal was input, without going through the optical switch of the Ph-GW 30. The fifth is a drop and insert function that enables processing at the Ph-GW 30 position to perform regeneration, relaying, and electrical processing.

[0023] In such a communication system 1, the user equipment 100 can transmit and receive control signals using AMCC not only to the APN controller 10 described above, but also between the user equipment 100. Hereinafter, regarding the user equipment 100, a configuration example of the user equipment 100 as a transmitting device and a configuration example of the user equipment 100 as a receiving device will be described. In the following description, a control signal for performing management control of communication using AMCC may be referred to as an AMCC signal.

[0024] (Example 1 of the transmitter configuration) 2 is a diagram showing a first configuration example of a transmission device. A transmission device 200 in the first configuration example is composed of a digital signal processing unit 210, a DA conversion unit 220, a light source 230, and an intensity modulation unit 240. The digital signal processing unit 210 is composed of an acquisition unit 211 and a modulation control unit 212.

[0025] The light source 230 generates a frequency modulated signal by a bias applied by the DA conversion unit 220. The light source 230 is, for example, a distributed feedback (DFB) laser. The frequency modulated signal is generated by modulating the bias of the light source 230 to cause a phase transition or an oscillation frequency of the laser called chirp. Thus, the light source 230 is capable of performing phase modulation or frequency modulation. In the following description, the phase modulation or frequency modulation is expressed as "phase / frequency modulation".

[0026] In addition, in accordance with the modulation of the bias of the light source 230, not only frequency modulation but also intensity modulation components are applied. Therefore, the output signal of the light source 230 undergoes phase and frequency transitions and output intensity changes according to the modulation of the bias. The light source 230 is an example of a second modulation section.

[0027] The intensity modulation section 240 is provided after the light source 230. The intensity modulation section 240 performs intensity modulation on the optical signal output from the light source 230 by a bias applied by the DA conversion section 220. The intensity modulation section 240 is, for example, an electroabsorption modulator (EA modulator) or a Mach-Zehnder type modulator. The intensity modulation section 240 is an example of a first modulation section.

[0028] The digital signal processing unit 210 performs signal processing of the information to be transmitted. The information to be transmitted includes user data and data to be transmitted as an AMCC signal. The acquisition unit 211 acquires a modulation method receivable by a receiving device that receives an AMCC signal. In this embodiment, the modulation methods receivable by the receiving device are an intensity modulation method, a modulation method that uses both intensity modulation and phase / frequency modulation, and a phase / frequency modulation method. In the following description, the intensity modulation method may be expressed as "method A". The phase / frequency modulation method may be expressed as "method B". The modulation method that uses both intensity modulation and phase / frequency modulation may be expressed as "method AB".

[0029] The acquisition method by the acquisition unit 211 includes a method of storing the modulation scheme receivable by the receiving device in a storage unit provided in advance in the transmitting device 200 and acquiring the modulation scheme from the storage unit. Another acquisition method includes a method of acquiring the modulation scheme based on information acquired from an external communication path different from the communication system 1. The acquisition unit 211 is an example of a receiving modulation scheme acquisition unit.

[0030] The modulation control unit 212 controls the DA conversion unit 220 in accordance with the modulation method acquired by the acquisition unit 211, thereby modulating the AMCC signal by the light source 230 or the intensity modulation unit 240. In the following description, application of a bias for transmitting a main signal may be simply expressed as "applying a main signal". Also, application of a bias for transmitting an AMCC signal may be simply expressed as "applying an AMCC signal".

[0031] An embodiment for each modulation method will be described below. (Example of modulation method A in configuration example 1 of the transmitting device) This shows an embodiment in the case where the acquisition unit 211 has acquired that the modulation method that the receiving device can receive is modulation method A. Fig. 3 and Fig. 4 are diagrams showing an embodiment in modulation method A. In Fig. 3, "DATA" indicates the main signal, and "AMCC" indicates the AMCC signal. Note that in the diagrams to be described below, "DATA" indicates the main signal, and "AMCC" indicates the AMCC signal.

[0032] 3, the modulation control unit 212 applies the main signal DATA to the light source 230, thereby modulating the main signal DATA by the light source 230. The modulation control unit 212 also applies an AMCC signal to the intensity modulation unit 240, thereby modulating the AMCC signal by the intensity modulation unit 240. As a result, the signal output by the light source 230 does not cause a frequency transition corresponding to the AMCC signal, so that only a receiving device capable of receiving the AMCC signal for intensity modulation can receive the AMCC signal.

[0033] Fig. 4 is a diagram showing an embodiment in which a pattern is applied to cancel the modulation component by the light source 230. In Fig. 4, "data" represents a signal that cancels the main signal DATA. In the diagrams to be described below, "data" also represents a signal that cancels the main signal DATA.

[0034] 4, the modulation control unit 212 applies the main signal DATA to the light source 230, thereby modulating the main signal DATA by the light source 230. The modulation control unit 212 also applies the AMCC signal and the cancellation signal data to the intensity modulation unit 240, thereby modulating the AMCC signal and the cancellation signal data by the intensity modulation unit 240. In this way, the intensity modulation component of the main signal DATA may be removed.

[0035] (Example of modulation method AB in configuration example 1 of the transmitting device) This shows an embodiment in the case where the acquisition unit 211 acquires that the modulation method receivable by the receiving device is modulation method AB. Fig. 5 and Fig. 6 are diagrams showing an embodiment in modulation method AB. In Fig. 5, the modulation control unit 212 applies a main signal DATA and an AMCC signal to the light source 230, thereby modulating the main signal DATA and the AMCC signal by the light source 230. The modulation control unit 212 also applies a cancellation signal data to the intensity modulation unit 240, thereby modulating the cancellation signal data by the intensity modulation unit 240. In this way, the intensity modulation component of the main signal DATA may be removed.

[0036] 6 is a diagram showing an embodiment for improving the modulation depth of the intensity modulation of the AMCC signal. When applying CPFSK modulation, the amplitude of the signal applied to the light source 230 is very small in order to keep the frequency shift to a minimum. Therefore, there may be cases where the amplitude of the intensity modulation component of the AMCC signal is not sufficient for reception.

[0037] 6, the modulation control unit 212 applies a main signal DATA and an AMCC signal to the light source 230, thereby modulating the main signal DATA and the AMCC signal by the light source 230. The modulation control unit 212 also applies a cancellation signal DATA and an AMCC signal to the intensity modulation unit 240, thereby modulating the cancellation signal DATA and the AMCC signal by the intensity modulation unit 240. In this way, the intensity modulation unit 240 can modulate the AMCC signal modulated by the light source 230 in the same pattern as the AMCC signal modulated by the light source 230, thereby achieving a desired modulation degree.

[0038] (Example of modulation method B in configuration example 1 of the transmitting device) This shows an embodiment in the case where the acquisition unit 211 has acquired that the modulation method receivable by the receiving device is modulation method B. Fig. 7 and Fig. 8 are diagrams showing an embodiment in modulation method B. In Fig. 7, "amcc" indicates a signal that cancels out an AMCC signal. In the figures to be described below, "amcc" also indicates a signal that cancels out an AMCC signal.

[0039] 7, the modulation control unit 212 applies a main signal DATA and an AMCC signal to the light source 230, thereby modulating the main signal DATA and the AMCC signal by the light source 230. The modulation control unit 212 also applies a cancellation signal amcc to the intensity modulation unit 240, thereby modulating the cancellation signal amcc by the intensity modulation unit 240. In this way, the intensity modulation component of the AMCC signal may be removed.

[0040] Fig. 8 is a diagram showing an embodiment for improving the reception sensitivity of the main signal DATA in a receiving device. In Fig. 8, the modulation control unit 212 applies the main signal DATA and the AMCC signal to the light source 230, thereby modulating the main signal DATA and the AMCC signal by the light source 230. The modulation control unit 212 also applies the cancellation signal data and the cancellation signal amcc to the intensity modulation unit 240, thereby modulating the cancellation signal data and the cancellation signal amcc by the intensity modulation unit 240. In this way, the intensity modulation component of the main signal DATA may be removed.

[0041] The flow of processing in the configuration example 1 of the transmitting device described above will be described. FIG. 9 is a flowchart showing the flow of processing in the configuration example 1 of the transmitting device. In FIG. 9, the acquisition unit 211 acquires a receivable modulation method (step S101). The acquired modulation method is notified to the modulation control unit 212. The modulation control unit 212 determines whether the acquired modulation method is modulation method A or not (step S102). If the acquired modulation method is modulation method A, the modulation control unit 212 applies an AMCC signal to the intensity modulation unit 240 by controlling the DA conversion unit 220 (step S103). On the other hand, if the acquired modulation method is not modulation method A, the acquired modulation method is modulation method AB or modulation method B. Therefore, the modulation control unit 212 applies an AMCC signal to the light source 230 by controlling the DA conversion unit 220 (step S104).

[0042] (An embodiment corresponding to modulation method A and modulation method B in configuration example 1 of the transmitting device) In the configuration example 1 of the transmitting device, an embodiment at the time of point-to-multipoint communication is shown. The transmitting device communicates with receiving device a and receiving device b. Receiving device a is capable of receiving with modulation method A, and receiving device b is capable of receiving with modulation method B.

[0043] Fig. 10 is a diagram showing an embodiment during point-to-multipoint communication. In Fig. 7, "AMCCa" indicates an AMCC signal for receiving device a. "AMCCb" indicates an AMCC signal for receiving device b. "amccb" indicates a signal that cancels "AMCCb."

[0044] In Fig. 10, the modulation control unit 212 applies a main signal DATA and an AMCCb signal to the light source 230, thereby modulating the main signal DATA and the AMCCb signal by the light source 230. The modulation control unit 212 also applies a cancellation signal data and a cancellation signal amcc to the intensity modulation unit 240, thereby modulating the cancellation signal data, the cancellation signal amccb, and the AMCCa signal by the intensity modulation unit 240. This removes the intensity component caused by the direct modulation of the light source 230. The transmission of the AMCC signal to a plurality of receiving devices may be exchanged according to time slots using a time division multiplexing method. Also, communication using subcarriers may be performed in the configuration example 1 of the transmitting device.

[0045] As described above, in the configuration example 1, it is possible to provide a technique that is compatible with the modulation method of the AMCC signal of the communication destination.

[0046] (Example 2 of the transmitter configuration) 11 is a diagram showing a second configuration example of a transmitting device. In the second configuration example, an optical amplifier is provided after the intensity modulation unit in the first configuration example. The optical amplifier is, for example, an SOA (Semiconductor Optical Amplifier). Since the modulation band of the SOA is limited to several GHz, the second configuration example can be implemented only when the main signal rate is equal to or lower than the SOA modulation band.

[0047] The transmitting device 300 in the second configuration example is composed of a digital signal processing unit 310, a DA conversion unit 320, a light source 330, an intensity modulation unit 340, and an optical amplification unit 350. The digital signal processing unit 310 is composed of an acquisition unit 311 and a modulation control unit 312.

[0048] The light source 330 generates a frequency modulated signal by a bias applied by the DA conversion unit 320. The light source 330 is, for example, a distributed feedback (DFB) laser. The frequency modulated signal is generated by modulating the bias of the light source 330 to cause a transition in the laser oscillation frequency and phase, called chirp. Thus, the light source 330 is capable of performing phase modulation or frequency modulation.

[0049] In addition, in accordance with the modulation of the bias of the light source 330, not only a frequency modulation component but also an intensity modulation component is applied. Therefore, the output signal of the light source 330 undergoes a phase and frequency transition according to the modulation of the bias, and a change in output intensity occurs. The light source 330 is an example of a second modulation section.

[0050] The intensity modulation section 340 is provided after the light source 330. The intensity modulation section 340 performs intensity modulation on the optical signal output from the light source 330 by a bias applied by the DA conversion section 320. The intensity modulation section 340 is, for example, an electroabsorption modulator (EA modulator) or a Mach-Zehnder type modulator. The intensity modulation section 340 is an example of a first modulation section.

[0051] The optical amplifier 360 amplifies the optical signal modulated by the intensity modulation unit 340. The optical amplifier 360 uses a bias applied by the DA conversion unit 320 to superimpose an AMCC signal on the intensity-modulated optical signal or cancel it.

[0052] The digital signal processing unit 310 performs signal processing of information to be transmitted. The information to be transmitted includes user data and data to be transmitted as an AMCC signal. The acquisition unit 311 acquires a modulation method that can be received by a receiving device that receives the AMCC signal.

[0053] The acquisition unit 311 may acquire modulation schemes receivable by the receiving device from a storage unit provided in advance in the transmitting device 300. Another acquisition method may be based on information acquired from an external communication path different from the communication system 1. The acquisition unit 311 is an example of a receiving modulation scheme acquisition unit.

[0054] The modulation control unit 312 controls the DA conversion unit 320 in accordance with the modulation method acquired by the acquisition unit 311 to modulate the AMCC signal by the light source 330 or the optical amplification unit 350 .

[0055] (Example of modulation method A in configuration example 2 of the transmitting device) 12 shows an embodiment in which the acquisition unit 211 acquires that the modulation scheme receivable by the receiving device is modulation scheme A. FIG.

[0056] 12, the modulation control unit 212 applies a main signal DATA to the light source 230, thereby modulating the main signal DATA by the light source 230. The modulation control unit 212 also applies a cancellation signal data to the intensity modulation unit 240, thereby modulating the cancellation signal data by the intensity modulation unit 240. The modulation control unit 212 also applies an AMCC signal to the optical amplification unit 350, thereby superimposing the AMCC signal on the optical signal output from the intensity modulation unit 340.

[0057] (Example of modulation method AB in configuration example 2 of the transmitting device) This shows an embodiment in which the acquisition unit 211 has acquired that the modulation method receivable by the receiving device is modulation method AB. Fig. 13 is a diagram showing an embodiment in the case of modulation method AB.

[0058] 13, the modulation control unit 212 applies a main signal DATA and an AMCC signal to the light source 230, thereby modulating the main signal DATA and the AMCC signal at the light source 230. The modulation control unit 212 also applies a cancellation signal data to the intensity modulation unit 240, thereby modulating the cancellation signal data at the intensity modulation unit 240. The modulation control unit 212 also applies an AMCC signal to the optical amplification unit 350, thereby superimposing the AMCC signal on the optical signal output from the intensity modulation unit 340.

[0059] (Example of modulation method B in configuration example 2 of the transmitting device) 14 shows an embodiment in which the acquisition unit 211 acquires that the modulation method receivable by the receiving device is modulation method B. FIG.

[0060] 14, the modulation control unit 212 applies a main signal DATA and an AMCC signal to the light source 230, thereby modulating the main signal DATA and the AMCC signal at the light source 230. The modulation control unit 212 also applies a cancellation signal data to the intensity modulation unit 240, thereby modulating the cancellation signal data at the intensity modulation unit 240. The modulation control unit 212 also applies a cancellation signal amcc to the optical amplification unit 350, thereby superimposing the cancellation signal amcc on the optical signal output from the intensity modulation unit 340.

[0061] As described above, in the second configuration example, it is possible to provide a technique that is compatible with the modulation method of the AMCC signal of the communication destination.

[0062] (Example using amplification band in configuration example 2 of the transmitting device) Next, an embodiment using the amplification band of an optical amplifier provided after the intensity modulation unit 340 will be described. Fig. 15 is a diagram showing an example of the amplification band of an SOA. In Fig. 15, frequency f0 is not included in the amplification band, and frequency f1 is included in the amplification band. The SOA has a characteristic of not transmitting intensity modulated signal components in a low frequency range such as frequency f1. Therefore, an embodiment assuming transmission of an AMCC signal superimposed on a subcarrier will be described.

[0063] (Example of modulation method A using the amplification band in the configuration example 2 of the transmitting device) 16 shows an embodiment in which the acquisition unit 211 acquires that the modulation scheme receivable by the receiving device is modulation scheme A. FIG.

[0064] 16, the modulation control unit 212 applies the main signal DATA to the light source 230, thereby modulating the main signal DATA by the light source 230. The modulation control unit 212 also applies the cancellation signal data and the AMCC signal to the intensity modulation unit 240, thereby modulating the cancellation signal data and the AMCC signal by the intensity modulation unit 240. At this time, the intensity modulation unit 240 superimposes the AMCC signal at a frequency f1 within the SOA amplification band.

[0065] (Example of modulation method AB using the amplification band in the configuration example 2 of the transmitting device) This shows an embodiment in which the acquisition unit 211 has acquired that the modulation method receivable by the receiving device is modulation method AB. Fig. 17 is a diagram showing an embodiment in the case of modulation method AB.

[0066] 17, the modulation control unit 212 applies the main signal DATA and the AMCC signal to the light source 230, thereby modulating the main signal DATA and the AMCC signal at the light source 230. At this time, the light source 230 superimposes the AMCC signal at a frequency f1 within the SOA amplification band. The modulation control unit 212 also applies the cancellation signal data to the intensity modulation unit 240, thereby modulating the cancellation signal data at the intensity modulation unit 240.

[0067] (Example of modulation method B using the amplification band in the configuration example 2 of the transmitting device) 18 shows an embodiment in which the acquisition unit 211 has acquired that the modulation method receivable by the receiving device is modulation method B. FIG. 18 is a diagram showing an embodiment in which modulation method B is used.

[0068] 18, the modulation control unit 212 applies the main signal DATA and the AMCC signal to the light source 230, thereby modulating the main signal DATA and the AMCC signal with the light source 230. At this time, the light source 230 superimposes the AMCC signal at a frequency f0 outside the SOA amplification band. The modulation control unit 212 also applies the cancellation signal data to the intensity modulation unit 240, thereby modulating the cancellation signal data with the intensity modulation unit 240. As a result, the AMCC signal superimposed on the intensity modulation component is removed, but the AMCC signal superimposed on the wavelength transition caused by the frequency chirp remains, so that transmission can be performed using modulation method B.

[0069] Fig. 19 is a diagram showing an embodiment of point-to-multipoint communication. As shown in Fig. 19, the outside of the amplification band of the SOA is used as a subcarrier for modulation method B, and the modulation method within the amplification band of the SOA is used as a subcarrier for modulation method A. Note that subcarriers may be shared in combination with a time division multiplexing method.

[0070] As described above, in the configuration example 2, it is possible to provide a technique that is compatible with the modulation method of the AMCC signal of the communication destination by utilizing the amplification band.

[0071] (Example of user device configuration) 20 and 21 are diagrams showing examples of the configuration of a user device 100 including the above-mentioned transmitting devices 200 and 300. The user device 100 in FIG. 20 includes the transmitting device 200 or the transmitting device 300, a receiving device 700, and an uplink / downlink signal multiplexer / separator 600. The user device 100 in FIG. 21 includes the transmitting device 200 or the transmitting device 300, and a receiving device 700.

[0072] As shown in FIG. 20, the user device 100 of this embodiment may be a single-core bidirectional type having a multiplexing / separating section for uplink and downlink signals, or as shown in FIG. 21, it may be a two-core type in which transmitted and received signals are input and output at separate ports.

[0073] 22 is a diagram showing an example of the configuration of a receiving device 700 according to this embodiment. The receiving device 700 includes a receiving-side DSP 710, an AD conversion unit 720, and a polarization diversity receiving unit 730. The AD conversion unit 720 is provided in a stage subsequent to the polarization diversity receiving unit 730, and the receiving-side DSP 710 is provided in a stage subsequent to the AD conversion unit 720.

[0074] The polarization diversity receiver 730 performs intradyne detection. The signal photoelectrically converted by the polarization diversity receiver is converted into a digital signal by the AD converter 720. The receiver DSP demodulates the digital signal input from the AD converter 720 into the main signal and the AMCC signal.

[0075] (Example of receiving DSP configuration) Below, configuration examples of the three types of receiving DSPs 710 (710A, 710B, 710C) will be described.

[0076] (Example 1 of receiving DSP configuration) 23 is a diagram showing a configuration example of a receiving side DSP 710A. The receiving side DSP 710A is composed of a signal duplication unit 711A, a main signal processing unit 712A, an intensity modulation AMCC processing unit 713A, and a phase / frequency modulation AMCC processing unit 714A. The signal duplication unit 711A duplicates the signal input from the AD conversion unit 720, and outputs it to the main signal processing unit 712A, the intensity modulation AMCC processing unit 713A, and the phase / frequency modulation AMCC processing unit 714A.

[0077] The main signal processing unit 712A demodulates the main signal. The intensity modulation AMCC processing unit 713A demodulates the intensity modulated AMCC signal. The phase / frequency modulation AMCC processing unit 714A demodulates the phase / frequency modulated AMCC signal. Note that for the intensity modulated AMCC signal, a method of demodulating the signal after separating it from the main signal may be used, as described in Non-Patent Document 2, for example.

[0078] (Example 2 of receiving DSP configuration) 24 is a diagram showing a configuration example of a receiving side DSP 710B. The receiving side DSP 710B is composed of a signal duplication unit 711B, a main signal processing unit 712B, an intensity modulation AMCC processing unit 713B, a phase / frequency modulation AMCC processing unit 714B, a demodulation switching unit 715B, and an acquisition unit 716B. The signal duplication unit 711B duplicates the signal input from the AD conversion unit 720, and outputs it to the main signal processing unit 712B, the intensity modulation AMCC processing unit 713B, and the phase / frequency modulation AMCC processing unit 714B.

[0079] The main signal processing unit 712B demodulates the main signal. The intensity modulation AMCC processing unit 713B demodulates the intensity modulated AMCC signal. The phase / frequency modulation AMCC processing unit 714B demodulates the phase / frequency modulated AMCC signal.

[0080] The acquisition unit 716B acquires modulation methods (modulation methods A, B, AB) that can be transmitted by a transmitting device that transmits an AMCC signal. As an acquisition method by the acquisition unit 211, there is a method in which modulation methods that can be transmitted by the transmitting device are stored in advance in a storage unit provided in the receiving device 700 and acquired from the storage unit. As another acquisition method, there is a method in which acquisition is based on information acquired from an external communication path different from the communication system 1. The acquired modulation method is output to the demodulation switching unit 715B.

[0081] The demodulation switching unit 715B demodulates the AMCC signal by the intensity modulation AMCC processing unit 713B when the modulation method output from the acquisition unit 716B is method A. The demodulation switching unit 715B demodulates the AMCC signal by the phase / frequency modulation AMCC processing unit 714B when the modulation method output from the acquisition unit 716B is method B or method AB.

[0082] The flow of processing in the configuration example 2 of the receiving side DSP described above will be described. FIG. 25 is a flowchart showing the flow of processing in the configuration example 2 of the receiving side DSP. In FIG. 25, the acquisition unit 716B acquires a modulation method that can be transmitted (step S201). The acquired modulation method is notified to the demodulation switching unit 715B. The demodulation switching unit 715B judges whether the acquired modulation method is modulation method A or not (step S202). If the acquired modulation method is modulation method A, the demodulation switching unit 715B demodulates the AMCC signal in the intensity modulation AMCC processing unit 713B (step S203). On the other hand, if the acquired modulation method is not modulation method A, the acquired modulation method is modulation method AB or modulation method B. Therefore, the demodulation switching unit 715B demodulates the AMCC signal in the phase / frequency modulation AMCC processing unit 714B (step S204).

[0083] (Receiver DSP configuration example 3) 26 is a diagram showing an example of the configuration of a receiving DSP 710C. The receiving DSP 710C is composed of a signal duplication unit 711C, a main signal processing unit 712C, an intensity modulation AMCC processing unit 713C, a phase / frequency modulation AMCC processing unit 714C, and a signal detection unit 717C. The signal duplication unit 711C duplicates the signal input from the AD conversion unit 720, and outputs the duplicated signal to the main signal processing unit 712C and the signal detection unit 717C.

[0084] The main signal processing unit 712C demodulates the main signal. The intensity modulation AMCC processing unit 713C demodulates the intensity modulated AMCC signal. The phase / frequency modulation AMCC processing unit 714C demodulates the phase / frequency modulated AMCC signal. The signal detection unit 717C detects whether the AMCC signal is intensity modulated or phase / frequency modulated from the received signal pattern and signal strength. When the signal detection unit 717C detects that the AMCC signal is intensity modulated, it outputs a signal to the intensity modulation AMCC processing unit 713C. When the signal detection unit 717C detects that the AMCC signal is phase / frequency modulated, it outputs a signal to the phase / frequency modulation AMCC processing unit 714C. In this way, the signal detection unit 717C demodulates the AMCC signal by the intensity modulation AMCC processing unit 713C or the phase / frequency modulation AMCC processing unit 714C according to the detected modulation method.

[0085] The flow of processing in the configuration example 3 of the receiving side DSP described above will be described. FIG. 27 is a flowchart showing the flow of processing in the configuration example 3 of the receiving side DSP. In FIG. 27, the signal detection unit 717C detects whether the AMCC signal is intensity modulated or phase / frequency modulated (step S301). The signal detection unit 717C judges whether the detected modulation method is modulation method A or not (step S302). If the detected modulation method is modulation method A, the signal detection unit 717C outputs a signal to the intensity modulation AMCC processing unit 713C to demodulate the AMCC signal (step S303). On the other hand, if the detected modulation method is not modulation method A, the detected modulation method is modulation method AB or modulation method B. Therefore, the signal detection unit 717C outputs a signal to the phase / frequency modulation AMCC processing unit 714C to demodulate the AMCC signal (step S304).

[0086] As described above, by having a configuration for demodulating an intensity-modulated AMCC signal and a configuration for demodulating a phase / frequency-modulated AMCC signal, it is possible to provide technology that is compatible with the modulation method of the AMCC signal of the communication destination.

[0087] (Example of processing at initial connection) Next, an example of processing at the time of initial connection in the user equipment 100 including the above-mentioned transmission equipment will be described. Fig. 28 is a configuration diagram for explaining the processing at the time of initial connection. Fig. 28 shows user equipments 100-1 and 100-2, Ph-GW 30-1, and AMCC transceivers 800-1 and 800-2.

[0088] In Fig. 28, the user device 100-1 is the transmitting side, and the user device 100-2 is the receiving side. The AMCC transceiver 800-1 is the AMCC transceiver 800-1 to which the user device 100-1 connects at the time of initial connection. The AMCC transceiver 800-1 is equipped with a transceiver using intensity modulation-square detection. The AMCC transceiver 800-2 transmits and receives AMCC signals while the user devices 100-1 and 100-2 are communicating with each other.

[0089] Based on this configuration, the process at the time of initial connection will be described with reference to the sequence diagram at the time of initial connection in FIG.

[0090] In the initial state, the user equipment 100-1 is connected to an initial port of the Ph-GW 30-1, and is connected to the AMCC transceiver 800-1 via path X. The user equipment 100-1 communicates with the AMCC transceiver 800-1 by a jointly modulated AMCC signal, thereby performing initial authentication of the user equipment 100-1 (step S401) and securing a path to the user equipment 100-2 (switching to path Y: see FIG. 28). As a result, a communication path to the user equipment 100-2 is established.

[0091] When a communication path is established, the user device 100-1 transmits a continuity check signal using each modulation method. Each continuity check signal is transmitted to the AMCC transceiver 800-2 and the user device 100-2. For example, the user device 100-1 transmits a continuity check signal using modulation method A (step S402), transmits a continuity check signal using modulation method B (step S402), and transmits a continuity check signal using modulation method AB (step S403).

[0092] The AMCC signal is modulated by these continuity check signals in a modulation method that the user device 100-2 can receive. In FIG. 29, continuity check signals are transmitted by all of the modulation methods for ease of understanding. However, if it is found that the AMCC transceiver 800-2 and the user device 100-2 can communicate with each other by modulation method A, the subsequent continuity check signals (modulation method B, modulation method AB) do not need to be transmitted. The user device 100-2 may transmit the continuity check signal, or may perform the continuity check similarly after the communication path is established. The same is true for point-to-multipoint communication as shown in FIG. 10 and FIG. 19. When the time division multiplexing method is used, a delay time for time synchronization and collision avoidance may be given to the user device 100-1, as in the authentication phase of the PON system.

[0093] In addition, when the intensity modulation method is used, since the AMCC signal flowing on the communication path can be acquired relatively easily by inserting a simple receiver on the communication path, if a modulation method other than the intensity modulation method is available, communication may be performed using a modulation method other than the intensity modulation method. Compared to when the intensity modulation method is used, it is more difficult to acquire the AMCC signal, and it is possible to prevent eavesdropping by malicious third parties.

[0094] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included. [Industrial Applicability]

[0095] The present invention is applicable to communication systems that use AMCC signals. [Explanation of symbols]

[0096] 1 Communication system, 10 APN controller, 100 User device, 200 Transmitting device, 210 Digital signal processing unit, 211 Acquisition unit, 212 Modulation control unit, 220 Conversion unit, 230 Light source, 240 Intensity modulation unit, 300 Transmitting device, 310 Digital signal processing unit, 311 Acquisition unit, 312 Modulation control unit, 320 Conversion unit, 330 Light source, 330 Signal light source, 340 Intensity modulation unit, 350 Optical amplification unit, 360 Optical amplifier, 600 Splitter, 700 Receiving device, 711A Signal duplication unit, 711B Signal duplication unit, 711C Signal duplication unit, 712A Main signal processing unit, 712B Main signal processing unit, 712C Main signal processing unit, 713A Intensity modulation AMCC processing unit, 713B Intensity modulation AMCC processing unit, 713C Intensity modulation AMCC processing unit, 714A Phase / frequency modulation AMCC processing unit, 714B phase / frequency modulation AMCC processing unit, 714C phase / frequency modulation AMCC processing unit, 715B demodulation switching unit, 716B acquisition unit, 717C signal detection unit, 720 conversion unit, 730 polarization diversity receiving unit, 800-1 transceiver, 800-2 transceiver

Claims

1. a first modulation unit that intensity-modulates a control signal for performing management control of communication; A second modulation unit that phase-modulates or frequency-modulates the control signal; a reception modulation scheme acquisition unit that acquires a modulation scheme receivable by a receiving device that receives the control signal; a modulation control unit that modulates the control signal by the first modulation unit or the second modulation unit according to the modulation method acquired by the reception modulation method acquisition unit; A transmitting device comprising:

2. 2. The transmitting device according to claim 1, wherein, when the receiving device is capable of receiving a phase-modulated, frequency-modulated, and intensity-modulated signal, the second modulation unit modulates a main signal and the control signal, and the first modulation unit provided downstream of the second modulation unit modulates a signal that cancels out the main signal.

3. The transmitting device according to claim 2 , wherein the second modulation section modulates the control signal in addition to the signal that cancels the main signal modulated by the first modulation section.

4. 2. The transmitting device of claim 1, wherein, when transmitting the control signal to a first receiving device capable of receiving an intensity-modulated signal and transmitting the control signal to a second receiving device capable of receiving a phase-modulated or frequency-modulated signal, the second modulation unit modulates a main signal and the control signal for the second receiving device, and the first modulation unit provided downstream of the second modulation unit modulates a signal that cancels out the main signal, a signal that cancels out the control signal for the second receiving device, and the control signal for the first receiving device.

5. a receiving unit for receiving a control signal for performing management control of communications; a first demodulation unit that demodulates the intensity-modulated signal; a second demodulation unit for demodulating a phase-modulated or frequency-modulated signal; a duplicating unit that duplicates the control signal received by the receiving unit and outputs the duplicated control signal to the first demodulating unit and the second demodulating unit; a transmission modulation scheme acquisition unit that acquires a modulation scheme by which the control signal is modulated by a transmission device that transmits the control signal; a demodulation control unit that demodulates the control signal by the first demodulation unit or the second demodulation unit according to the modulation scheme acquired by the transmission modulation scheme acquisition unit; A receiving device comprising:

6. a receiving unit for receiving a control signal for performing management control of communications; a first demodulation unit that demodulates the intensity-modulated signal; a second demodulation unit for demodulating a phase-modulated or frequency-modulated signal; a signal detection unit that detects a modulation method of the control signal received by the receiving unit, and demodulates the control signal by the first demodulation unit or the second demodulation unit according to the detected modulation method; A receiving device comprising:

7. A method for controlling a transmission device that transmits a control signal for performing management control of communication, comprising the steps of: a reception modulation method acquisition step of acquiring a modulation method receivable by a receiving device that receives the control signal; a modulation control step of intensity-modulating, phase-modulating, or frequency-modulating the control signal in accordance with the modulation method acquired by the reception modulation method acquisition step; A control method comprising:

8. A method for controlling a receiving device that receives a control signal for performing management control of communication, comprising the steps of: a transmission modulation scheme acquisition step of acquiring a modulation scheme by which the control signal is modulated by a transmitting device that transmits the control signal; a modulation control step of demodulating the control signal as an intensity modulated signal or as a phase modulated or frequency modulated signal according to the modulation method acquired by the transmission modulation method acquisition step; A control method comprising:

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