Baseband Units and Access Network Devices

Abstract

The embodiment of the present application discloses a baseband unit BBU and an access network device. The BBU includes M lasers, M switches SW, M photodetectors PD, an arrayed waveguide grating AWG, M transmit ports, and M receive ports, where M is an integer equal to or greater than 2. The i-th laser is coupled to the input end of the i-th SW, the upper output end of the i-th SW is coupled to the i-th transmit port, and the AWG is separately coupled to the lower output ends of the M switches SW, M PDs, and M receive ports, where i=1, 2, ..., or M. In the embodiment of the present application, the BBU is compatible with gray dual fiber networking and CWDM networking. When the networking mode used by the BBU needs to be changed, the optical module or components in the BBU do not need to be replaced, and thus the applicability, universality, and flexibility of the BBU can be improved.

Description

[Technical field]

[0001] TECHNICAL FIELD Embodiments of the present application relate to the field of optical communication technology, and in particular to baseband units and access network devices. [Background technology]

[0002] With the development of the fifth generation mobile communication technology (5G), the amount of access network devices increases. There are multiple networking modes for transmission between a baseband unit (BBU) and an active antenna unit (AAU). When optical fiber resources are sufficient, gray dual fiber networking may be used for transmission between the BBU and the AAU. When optical fiber resources are insufficient, bidirectional (BiDi) single fiber networking may be used for transmission between the BBU and the AAU. When high optical fiber resource utilization is required, coarse wavelength-division multiplexing (CWDM) networking may be used for transmission between the BBU and the AAU. There are multiple networking modes for transmission between the BBU and the AAU, and it can be known that different networking modes require different optical modules for the BBU. As a result, when the networking mode used by the BBU needs to be changed, the optical module in the BBU needs to be replaced. As a result, the applicability of the BBU is poor. Summary of the Invention

[0003] The embodiments of the present application disclose a baseband unit and an access network device to improve the applicability of the BBU.

[0004] According to a first aspect, the present application discloses a BBU. The BBU may include M lasers, M switches (SWs), M photon detectors (PDs), arrayed waveguide gratings (AWGs), M transmit ports, and M receive ports, where M is an integer equal to or greater than 2. The i-th laser is coupled to an input end of the i-th SW, an upper output end of the i-th SW is coupled to the i-th transmit port, and the AWG is separately coupled to lower output ends of the M switches SWs, the M PDs, and the M receive ports, where i=1, 2, ..., or M.

[0005] In this embodiment of the present application, the BBU can be compatible with gray dual-fiber networking and CWDM networking. When the networking mode used by the BBU is changed from gray dual-fiber networking to CWDM networking or from CWDM networking to gray dual-fiber networking, the components or chips in the BBU do not need to be replaced, and thus the applicability, universality and flexibility of the BBU can be improved.

[0006] In a possible implementation, the BBU may further include M-1 multiplexers (MUXs), where the j-th MUX is separately coupled to the upper output end of the j-th SW, the j-th transmit port, and the AWG, where j=1, 2, ..., or M-1.

[0007] In this embodiment of the present application, the BBU can be compatible with gray dual-fiber networking, CWDM networking, and BiDi single-fiber bidirectional networking. When the networking mode used by the BBU is changed from gray dual-fiber networking to CWDM networking, from CWDM networking to gray dual-fiber networking, from BiDi single-fiber bidirectional networking to gray dual-fiber networking, from BiDi single-fiber bidirectional networking to CWDM networking, from CWDM networking to BiDi single-fiber bidirectional networking, or from BiDi single-fiber bidirectional networking to gray dual-fiber networking, the components or chips in the BBU do not need to be replaced, and thus the applicability, universality, and flexibility of the BBU can be improved.

[0008] In a possible implementation, the BBU may further include M modulators (MODs), where the i-th MOD is separately coupled to the input ends of the i-th laser and the i-th SW.

[0009] In this embodiment of the present application, the bandwidth of the MOD is high, and therefore high-rate transmission of optical signals can be implemented.

[0010] In a possible implementation, when the BBU is used for gray dual-fiber networking, the M transmit ports and the M receive ports are each coupled to one optical fiber. The M lasers are configured to send optical signals to the corresponding optical fibers through the corresponding SWs and the corresponding transmit ports. The M PDs are configured to receive optical signals from the corresponding optical fibers through the AWGs and the corresponding receive ports.

[0011] In a possible implementation, when the BBU is used for gray dual-fiber networking, the M transmit ports and the M receive ports are each coupled to one optical fiber. The jth laser is configured to send an optical signal to the corresponding optical fiber through the corresponding SW, the corresponding MUX, and the corresponding transmit port. The Mth laser is configured to send an optical signal to the corresponding optical fiber through the corresponding SW and the corresponding transmit port. The M PDs are configured to receive the optical signals from the corresponding optical fiber through the AWG and the corresponding receive port.

[0012] In a possible implementation, when the BBU is used for gray dual-fiber networking, the M transmit ports and the M receive ports are each coupled to one optical fiber. The jth laser is configured to send an optical signal to the corresponding optical fiber through the corresponding MOD, the corresponding SW, the corresponding MUX, and the corresponding transmit port. The Mth laser is configured to send an optical signal to the corresponding optical fiber through the corresponding MOD, the corresponding SW, and the corresponding transmit port. The M PDs are configured to receive optical signals from the corresponding optical fibers through the AWG and the corresponding receive ports.

[0013] In a possible implementation, when the BBU is used for CWDM networking, the first receive port is coupled to one optical fiber. The M lasers are configured to send optical signals to the optical fiber through corresponding SWs, AWGs, and the first receive ports. The M PDs are configured to receive optical signals from the optical fiber through the AWGs and the first receive ports.

[0014] In a possible implementation, when the BBU is used for CWDM networking, the first receive port is coupled to an optical fiber. The M lasers are configured to send optical signals to the optical fiber through corresponding MODs, corresponding SWs, AWGs, and the first receive port. The M PDs are configured to receive optical signals from the optical fiber through the AWGs and the first receive port.

[0015] In a possible implementation, when the BBU is used for bidirectional BiDi single-fiber bidirectional networking, the jth transmit port and the first receive port are each coupled to one optical fiber. The jth laser is configured to send an optical signal to the corresponding optical fiber through the corresponding SW, the corresponding MUX, and the corresponding transmit port. The Mth laser is configured to send an optical signal to the corresponding optical fiber through the corresponding SW, the AWG, and the first receive port. The jth PD is configured to receive an optical signal from the corresponding optical fiber through the AWG, the MUX, and the jth transmit port. The Mth PD is configured to receive an optical signal from the corresponding optical fiber through the AWG and the first receive port.

[0016] In a possible implementation, when the BBU is used for bidirectional BiDi single-fiber bidirectional networking, the jth transmit port and the first receive port are each coupled to an optical fiber. The jth laser is configured to send an optical signal to the corresponding optical fiber through the corresponding MOD, the corresponding SW, the corresponding MUX, and the corresponding transmit port. The Mth laser is configured to send an optical signal to the corresponding optical fiber through the corresponding MOD, the corresponding SW, the AWG, and the first receive port. The jth PD is configured to receive an optical signal from the corresponding optical fiber through the AWG, the MUX, and the jth transmit port. The Mth PD is configured to receive an optical signal from the corresponding optical fiber through the AWG and the first receive port.

[0017] In this embodiment of the present application, the BBU is compatible with gray dual-fiber networking, CWDM networking, and BiDi single-fiber bidirectional networking. When the networking mode used by the BBU is changed from gray dual-fiber networking to CWDM networking, from CWDM networking to gray dual-fiber networking, from BiDi single-fiber bidirectional networking to gray dual-fiber networking, from BiDi single-fiber bidirectional networking to CWDM networking, from CWDM networking to BiDi single-fiber bidirectional networking, or from BiDi single-fiber bidirectional networking to gray dual-fiber networking, the components or chips in the BBU do not need to be replaced, and the networking change can be implemented only by using different optical fiber connection methods, and thus the applicability, universality, and flexibility of the BBU can be improved.

[0018] In a possible implementation, the laser may be a directly modulated laser (DML).

[0019] In this embodiment of the present application, the DML may implement the functions of a laser and a modulator, and no additional modulator is required, and the amount of components can be reduced, thereby reducing the area of ​​the BBU.

[0020] In a possible implementation, the laser may be a semiconductor laser.

[0021] In this embodiment of the present application, the area of ​​the semiconductor laser is small, therefore the area of ​​the BBU can be reduced.

[0022] According to a second aspect, the present application discloses an access network device. The access network device may include an AAU and a BBU as disclosed in the first aspect. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2 is a diagram of the structure of an access network device according to an embodiment of the present application. [Diagram 2] FIG. 2 is a diagram of gray dual fiber networking used between a BBU and an AAU according to an embodiment of the present application. [Diagram 3] FIG. 2 is a diagram of BiDi single-fiber bidirectional networking used between a BBU and an AAU according to an embodiment of the present application. [Figure 4] FIG. 2 is a diagram of CWDM networking used between a BBU and an AAU according to an embodiment of the present application. [Diagram 5] FIG. 2 is a diagram of a structure of a BBU according to an embodiment of the present application. [Figure 6] FIG. 13 is a diagram of a structure of another BBU according to an embodiment of the present application. [Figure 7] FIG. 13 is a diagram of a structure of yet another BBU according to an embodiment of the present application. [Figure 8] FIG. 13 is a diagram of a structure of yet another BBU according to an embodiment of the present application. [Figure 9] FIG. 13 is a diagram of a structure of yet another BBU according to an embodiment of the present application. [Figure 10] FIG. 2 is a diagram of a BBU used for gray dual fiber networking according to an embodiment of the present application. [Figure 11] FIG. 2 illustrates a route mapping table of an AWG according to an embodiment of the present application; [Figure 12] FIG. 2 is a diagram of a BBU used for CWDM networking according to an embodiment of the present application. [Figure 13] FIG. 13 illustrates another route mapping table of an AWG according to an embodiment of the present application; [Figure 14]FIG. 2 is a diagram of a BBU used for BiDi single-fiber bidirectional networking according to an embodiment of the present application. [Figure 15] FIG. 13 illustrates yet another route mapping table of an AWG according to an embodiment of the present application; [Figure 16] FIG. 13 is a diagram of a structure of yet another BBU according to an embodiment of the present application. [Figure 17] FIG. 13 is a diagram of a structure of yet another BBU according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The embodiments of the present application disclose a baseband unit and an access network device for improving the applicability of the BBU, the details of which are described separately below.

[0025] In order to better understand the baseband unit and the access network device disclosed in the embodiment of the present application, the following will first describe the access network device used in the embodiment of the present application. Figure 1 is a diagram of a structure of an access network device according to the embodiment of the present application. As shown in Figure 1, the access network device may include a BBU and an AAU. The BBU is connected to the AAU through an optical fiber. The BBU is configured to send an optical signal to the AAU through the optical fiber. The AAU is configured to receive an optical signal from the BBU and send the optical signal to the BBU. The BBU is further configured to receive an optical signal from the AAU.

[0026] An access network device is a radio access network (RAN) node (or device) that connects terminal devices to a wireless network, and is also sometimes called a base station.

[0027] In order to better understand the baseband unit and access network device disclosed in the embodiments of the present application, the following first describes related technologies in the embodiments of the present application.

[0028] FIG. 2 is a diagram of the gray dual fiber networking used between the BBU and the AAU according to an embodiment of the present application. As shown in FIG. 2, the wavelengths of the optical signals generated by all the optical modules in the BBU are the same. For example, the wavelengths are all 1311 nanometers (nm). Each of the optical modules has two external ports, a transport (T) port and a receive (R) port.

[0029] 3 is a diagram of a BiDi single-fiber bidirectional network used between a BBU and an AAU according to an embodiment of the present application. As shown in FIG. 3, each of the optical modules in the BBU includes a filter. The filter can transmit an optical signal having a wavelength of 1331 nm and reflect an optical signal having a wavelength of 1271 nm. Each of the optical modules has an external port.

[0030] FIG. 4 is a diagram of CWDM networking used between a BBU and an AAU according to an embodiment of the present application. As shown in FIG. 4, the wavelengths of the optical signals generated by all the optical modules in the BBU are different. Each of the optical modules has two external ports, a T port and an R port. In addition, the BBU is coupled to the AAU through two MUXs. One MUX is separately coupled to the external ports of the optical modules in the BBU, and the other MUX is separately coupled to the external ports of the optical modules in the AAU.

[0031] The different wavelengths of the optical signals generated by the optical modules indicate that the lasers generating the optical signals in the optical modules are different, and therefore the optical modules can be determined to be different. When different networking modes are used between the BBU and the AAU, it can be known that different optical modules are used in the BBU. As a result, when the networking mode used by the BBU needs to be changed, the optical module in the BBU needs to be replaced. As a result, the applicability of the BBU is poor.

[0032] 5 is a diagram of a structure of a BBU according to an embodiment of the present application. As shown in FIG. 5, the BBU may include M lasers, M SWs, M PDs, AWGs, M T ports, and M R ports, where M is an integer equal to or greater than 2.

[0033] The i-th laser is coupled to the input end of the i-th SW, the upper output end of the i-th SW is coupled to the i-th T port, and the AWG is separately coupled to the lower output ends of the M SWs, the M PDs, and the M R ports, where i=1, 2, ..., or M.

[0034] It should be understood that the coupling between different components in this embodiment of the present application is an optical coupling. The optical coupling can be a fiber optic coupling or a waveguide coupling. For example, when two components are connected through an optical fiber, the optical coupling between the two components is a fiber optic coupling. For example, when two components are connected and integrated on the same chip, the optical coupling between the two components is a waveguide coupling.

[0035] Optionally, when the BBU is used for gray dual-fiber networking, specifically, when gray dual-fiber networking is used for transmission between the BBU and the AAU, the M T ports and the M R ports are each coupled to one optical fiber (wherein the optical fibers coupled to the T ports and the R ports are not shown in the figure).

[0036] The M lasers are configured to send optical signals to corresponding optical fibers through corresponding SWs and corresponding T-ports.

[0037] The M PDs are configured to receive optical signals from corresponding optical fibers through the AWG and corresponding R ports.

[0038] Optionally, when the BBU is used for CWDM networking, specifically, when CWDM networking is used for transmission between the BBU and the AAU, the first R port is coupled to one optical fiber (wherein the optical fiber coupled to the R port is not shown in the figure).

[0039] The M lasers are configured to send optical signals through the corresponding SW, AWG, and the first R port into the optical fiber.

[0040] The M PDs are configured to receive optical signals from the optical fiber through the AWG and the first R port.

[0041] When the BBU is used for gray dual-fiber networking, each of the M T ports and the M R ports is coupled to one optical fiber, i.e., the BBU needs to be coupled to 2M optical fibers. In other words, the BBU can be coupled to the AAU through 2M optical fibers.

[0042] When the BBU sends an optical signal to the AAU, the M lasers each send the optical signal to a corresponding optical fiber through a corresponding SW and a corresponding T-port. In particular, the i-th laser is configured to send an optical signal to the i-th SW. The i-th SW is configured to receive an optical signal from the i-th laser and send the received optical signal to the i-th T-port through an upper output end of the i-th SW. The i-th T-port is configured to receive an optical signal from the i-th SW and send the received optical signal to the AAU through a corresponding optical fiber.

[0043] When the AAU sends an optical signal to the BBU, the M PDs respectively receive the optical signal from the corresponding optical fiber through the AWG and the corresponding R port. In particular, the i-th R port is configured to receive the optical signal from the AAU through the corresponding optical fiber and send the received optical signal to the AWG. The AWG is configured to receive the optical signals from the M R ports and send the received M optical signals to the M PDs respectively based on the route mapping table. The i-th PD is configured to receive the corresponding optical signal from the AWG and convert the received optical signal into an electrical signal. The route mapping table specifies a mapping relationship between different ports in the AWG, and this mapping relationship further relates to the wavelength of the optical signal. For example, when the wavelength of the optical signal received by the AWG through port 1 is A1, the AWG may send the optical signal through port 2 based on the route mapping table, or when the wavelength of the optical signal received by the AWG through port 1 is A2, the AWG may send the optical signal through port 3 based on the route mapping table. It can be known that the port through which the AWG sends a received optical signal is determined by the port through which the AWG receives the optical signal and the wavelength of the optical signal.

[0044] When the BBU is used for CWDM networking, the first R port is coupled to one optical fiber. The BBU only needs to be coupled to an optical fiber, in other words, the BBU can be coupled to the AAU through only one optical fiber. When the BBU sends an optical signal to the AAU, the M lasers send the optical signal to the optical fiber through the corresponding SW, AWG, and first R port, respectively. In particular, the i-th laser is configured to send the optical signal to the i-th SW. The i-th SW is configured to receive the optical signal from the i-th laser and send the received optical signal to the AWG through the lower output end. The AWG is configured to receive the M optical signals from the M SWs, perform multiplexing processing on the M optical signals, and send the multiplexed optical signal to the first R port. The first R port is configured to receive the multiplexed optical signal from the AWG and send the multiplexed optical signal to the AAU through the optical fiber. The wavelengths of the M optical signals generated by the M lasers are different. A multiplexed optical signal is obtained by multiplexing M optical signals with different wavelengths.

[0045] When the AAU sends an optical signal to the BBU, the M PDs respectively receive the optical signals from the optical fiber through the AWG and the first R port. In particular, the first R port is configured to receive the M optical signals from the AAU through the optical fiber and send the M optical signals to the AWG. The AWG is further configured to receive the M optical signals from the first R port and send the M optical signals to the M PDs respectively based on the route mapping table. The i-th PD is configured to receive the corresponding optical signal from the AWG and convert the received optical signal into an electrical signal. For a detailed description of the route mapping table, please refer to the related content above.

[0046] It may be known that the BBU may be compatible with gray dual-fiber networking and CWDM networking. When the networking mode used by the BBU is changed from gray dual-fiber networking to CWDM networking or from CWDM networking to gray dual-fiber networking, the components or chips in the BBU do not need to be replaced, and the networking change can be implemented only by using a different optical fiber connection method, and thus the applicability, universality, and flexibility of the BBU may be improved.

[0047] Figure 6 is a diagram of the structure of another BBU according to an embodiment of the present application. The BBU shown in Figure 6 may be obtained based on the BBU shown in Figure 5. As shown in Figure 6, the BBU may further include M-1 MUXes.

[0048] The jth MUX is separately coupled to the upper output end of the jth SW, the jth T port, and the AWG, where j=1, 2, . . . , or M-1.

[0049] It should be understood that the MUX has a filtering function and can transmit optical signals with preset wavelengths and reflect optical signals different from the optical signals with preset wavelengths.

[0050] Optionally, when the BBU is used for gray dual-fiber networking, specifically when gray dual-fiber networking is used for transmission between the BBU and the AAU, the M T ports and the M R ports are each coupled to an optical fiber (wherein the optical fibers coupled to the T ports and the R ports are not shown in the figure).

[0051] The jth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding SW, a corresponding MUX, and a corresponding T port.

[0052] The Mth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding SW and a corresponding T port.

[0053] The M PDs are configured to receive optical signals from corresponding optical fibers through the AWG and corresponding R ports.

[0054] Optionally, when the BBU is used for BiDi single-fiber bidirectional networking, the jth T port and the first R port are each coupled to one optical fiber.

[0055] The jth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding SW, a corresponding MUX, and a corresponding T port.

[0056] The Mth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding SW, an AWG, and the first R port.

[0057] The jth PD is configured to receive an optical signal from a corresponding optical fiber through the AWG, the MUX, and the jth T port.

[0058] The Mth PD is configured to receive an optical signal from a corresponding optical fiber through the AWG and the first R port.

[0059] When the BBU is used for gray dual-fiber networking, the M T ports and the M R ports are each coupled to one optical fiber. When the BBU sends an optical signal to the AAU, the jth laser sends the optical signal to the corresponding optical fiber through the corresponding SW, the corresponding MUX, and the corresponding T port. In particular, the jth laser is configured to send the optical signal to the jth SW. The jth SW is configured to receive the optical signal from the jth laser and send the received optical signal to the jth MUX through the upper output end of the jth SW. The jth MUX is configured to receive the optical signal from the jth SW and send the received optical signal to the jth T port. The jth T port is configured to receive the optical signal from the jth MUX and send the received optical signal to the AAU through the corresponding optical fiber. The Mth laser sends the optical signal to the corresponding optical fiber through the corresponding SW and the corresponding T port, in particular, the Mth laser sends the optical signal to the corresponding optical fiber through the Mth SW and the Mth T port. In particular, the Mth laser is configured to send an optical signal to the Mth SW. The Mth SW is configured to receive the optical signal from the Mth laser and send the received optical signal through an upper output end of the Mth SW to the Mth T port. The Mth T port is configured to receive the optical signal from the Mth SW and send the received optical signal through a corresponding optical fiber to the AAU.

[0060] When the AAU sends the optical signal to the BBU, the M PDs respectively receive the optical signal from the corresponding optical fiber through the AWG and the corresponding R port. For detailed description, please refer to the corresponding description in Figure 5. The details will not be described again in this specification.

[0061] For a detailed description of the BBU used for CWDM networking, please refer to the corresponding description in Figure 5. The details will not be described again here.

[0062] When the BBU is used for BiDi single-fiber bidirectional networking, the jth T port and the first R port are each coupled to one optical fiber, i.e., the BBU needs to be coupled to M optical fibers. In other words, the BBU can be coupled to the AAU through M optical fibers. When the BBU sends an optical signal to the AAU, the jth laser sends the optical signal to the corresponding optical fiber through the corresponding SW, the corresponding MUX, and the corresponding T port. In particular, the jth laser is configured to send the optical signal to the jth SW. The jth SW is configured to receive the optical signal from the jth laser and send the received optical signal to the jth MUX through the upper output end of the jth SW. The jth MUX is configured to receive the optical signal from the jth SW and send the received optical signal to the jth T port. The jth T port is configured to receive the optical signal from the jth MUX and send the received optical signal to the AAU through the corresponding optical fiber. The Mth laser sends the optical signal to the corresponding optical fiber through the corresponding SW, the AWG, and the first R port. In particular, the Mth laser is configured to send the optical signal to the Mth SW. The Mth SW is configured to receive the optical signal from the Mth laser and send the received optical signal to the AWG through a lower output end of the Mth SW. The AWG is configured to receive the optical signal from the Mth SW and send the received optical signal to the first R port based on the route mapping table. The Mth R port is configured to receive the optical signal from the AWG and send the received optical signal to the AAU through the corresponding optical fiber.

[0063] When the AAU sends the optical signal to the BBU, the jth PD receives the optical signal from the corresponding optical fiber through the AWG and the jth T port. In particular, the jth T port is configured to receive the optical signal from the AAU through the corresponding optical fiber and send the received optical signal to the jth MUX. The jth MUX is configured to receive the optical signal from the jth T port and send the received optical signal to the AWG. The AWG is configured to receive the optical signal from the jth MUX and send the received optical signal to the jth PD based on the route mapping table. The jth PD is configured to receive the optical signal from the AWG and convert the received optical signal into an electrical signal. The Mth PD receives the optical signal from the corresponding optical fiber through the AWG and the first R port. In particular, the first R port is configured to receive the optical signal from the AAU through the corresponding optical fiber and send the received optical signal to the AWG. The AWG is further configured to receive the optical signal from the first R port and send the received optical signal to the Mth PD based on the route mapping table. The Mth PD is configured to receive the optical signal from the AWG and convert the received optical signal into an Mth electrical signal.

[0064] When the BBU includes M lasers and M PDs, 4M-1 ports are disposed on the AWG, and the M lasers and M PDs are respectively coupled to 2M ports of the 4M-1 ports of the AWG, in other words, the M lasers and M PDs are respectively coupled to one port on the AWG, and the M-1 MUXs and M R ports are respectively coupled to the remaining 2M-1 ports of the 4M-1 ports of the AWG.

[0065] It may be known that the BBU may be compatible with gray dual-fiber networking, CWDM networking, and BiDi single-fiber bidirectional networking. When the networking mode used by the BBU is changed from gray dual-fiber networking to CWDM networking, from CWDM networking to gray dual-fiber networking, from BiDi single-fiber bidirectional networking to gray dual-fiber networking, from BiDi single-fiber bidirectional networking to CWDM networking, from CWDM networking to BiDi single-fiber bidirectional networking, or from BiDi single-fiber bidirectional networking to gray dual-fiber networking, no components or chips in the BBU need to be replaced, and the networking change can be implemented only by using different optical fiber connection methods, and thus the applicability, universality, and flexibility of the BBU can be improved.

[0066] Fig. 7 is a diagram of the structure of yet another BBU according to an embodiment of the present application. The BBU shown in Fig. 7 may be obtained based on the BBU shown in Fig. 6. As shown in Fig. 7, the BBU may further include M MODs.

[0067] The i-th MOD is separately coupled to the input ends of the i-th laser and the i-th SW.

[0068] Optionally, when the BBU is used for gray dual-fiber networking, specifically when gray dual-fiber networking is used for transmission between the BBU and the AAU, the M T ports and the M R ports are each coupled to an optical fiber (wherein the optical fibers coupled to the T ports and the R ports are not shown in the figure).

[0069] The jth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding MOD, a corresponding SW, a corresponding MUX, and a corresponding T port.

[0070] The Mth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding MOD, a corresponding SW, and a corresponding T port.

[0071] The M PDs are configured to receive optical signals from corresponding optical fibers through the AWG and corresponding R ports.

[0072] Optionally, when the BBU is used for CWDM networking, specifically, when CWDM networking is used for transmission between the BBU and the AAU, the first R port is coupled to one optical fiber (wherein the optical fiber coupled to the R port is not shown in the figure).

[0073] The M lasers are configured to send optical signals through a corresponding MOD, a corresponding SW, an AWG, and the first R port into the optical fiber.

[0074] The M PDs are configured to receive optical signals from the optical fiber through the AWG and the first R port.

[0075] Optionally, when the BBU is used for BiDi single-fiber bidirectional networking, the jth T port and the first R port are each coupled to an optical fiber (wherein the optical fibers coupled to the T port and the R port are not shown in the figure).

[0076] The jth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding MOD, a corresponding SW, a corresponding MUX, and a corresponding T port.

[0077] The Mth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding MOD, a corresponding SW, an AWG, and the first R port.

[0078] The jth PD is configured to receive an optical signal from a corresponding optical fiber through the AWG, the MUX, and the jth T port.

[0079] The Mth PD is configured to receive an optical signal from a corresponding optical fiber through the AWG and the first R port.

[0080] The laser may first send an optical signal to the MOD. The MOD modulates the optical signal, and then sends the modulated optical signal to the MUX, the T-port, or the AWG. The subsequent optical signal processing method is the same as that described above. For detailed explanations, please refer to the related explanations above. Details will not be described again in this specification. After the MOD is added to the BBU, the bandwidth of the MOD is high, so that the transmission of the optical signal at a high rate can be implemented.

[0081] FIG. 8 is a diagram of the structure of yet another BBU according to an embodiment of the present application. The BBU shown in FIG. 8 may be obtained based on the BBU shown in FIG. 5 to FIG. 7. As shown in FIG. 8, the i-th laser in FIG. 5 or FIG. 6 may be replaced with the i-th directly modulated laser (DML). Since the DML has the functions of laser and MOD, it may also be understood that the i-th laser and the i-th MOD in FIG. 7 are replaced with the i-th DML in FIG. 8. The i-th DML is configured to send the modulated i-th optical signal to the i-th SW. The subsequent optical signal processing method is the same as that in the above embodiment. For detailed description, please refer to the related description above. Details will not be described again in this specification. After the DML is added to the BBU, since the DML can implement the functions of laser and modulator, no additional modulator is needed, and the amount of components in the BBU can be reduced, thereby reducing the area of ​​the BBU.

[0082] The laser in the above embodiment may be a semiconductor laser, a solid-state laser, a gas laser, or a dye laser. For example, the laser may be a laser diode (LD). The above examples are merely examples for describing the laser, and do not constitute limitations on the laser.

[0083] The MOD in the above embodiments may be a Mach-Zehnder modulator (MZM), an electro-absorption modulator, a micro-ring modulator, or another modulator, which is not limited herein.

[0084] The SW in the above embodiments may be a Mach-Zehnder interferometer (MZI) switch, a micro-electro-mechanical system (MEMS) switch, a liquid crystal on silicon (LCOS) switch, or another switch, which is not limited herein.

[0085] The MUX in the above embodiment may be a thin film filter (TFF), a MZI cascade, an AWG, or another MUX, which is not limited herein.

[0086] The above BBU is further explained below by using an example. M is assumed to be 3.

[0087] FIG. 9 is a diagram of the structure of yet another BBU according to an embodiment of the present application. As shown in FIG. 9, the BBU may include three lasers, three MODs, three PDs, one AWG, two MUXs, three transmit ports, and three receive ports. The wavelength of the optical signal generated by the first laser is 1371 nm, the wavelength of the optical signal generated by the second laser is 1351 nm, and the wavelength of the optical signal generated by the third laser is 1331 nm. Each of the lasers with wavelengths of 1331 nm, 1351 nm, and 1371 nm is coupled to a corresponding SW after being modulated by one MOD. The upper output ports of the first SW and the second SW are respectively coupled to a corresponding T port through a corresponding MUX. The upper output of the third SW is coupled to a corresponding T port. The AWG is separately coupled to the lower outputs of the three SWs, the R port of the 1371 nm channel, the R port of the 1351 nm channel, the R port of the 1331 nm channel, two MUXs, and three PDs.

[0088] FIG. 10 is a diagram of a BBU used for gray dual-fiber networking according to an embodiment of the present application. As shown in FIG. 10, the optical signals generated by the first laser and the second laser are output by using the upper output port of the corresponding SW after being modulated by the corresponding MOD, and then are sent to the AAU through the corresponding T port after being combined through the corresponding MUX. The optical signal generated by the third laser is output by using the upper output port of the corresponding SW after being modulated by the corresponding MOD, and is sent to the AAU through the corresponding T port. The AAU receives the corresponding optical signal by using the wide spectrum of the corresponding optical module. The AAU sends the 1311 nm optical signals, specifically, 1311-1, 1311-2, and 1311-3, to the first R port, the second R port, and the third R port in the BBU, respectively. After receiving the optical signals from the AAU, the first R port, the second R port, and the third R port send the optical signals to the AWG. FIG. 11 shows a route mapping table of an AWG according to an embodiment of the present application. The AWG may send three optical signals to three PDs respectively based on the route mapping table of FIG. 11. For example, when the AWG receives an optical signal having a wavelength of 1311 nm through the right port 1, the AWG may send an optical signal through the left port 6. As shown in FIG. 10 and FIG. 11, optical signals having the same wavelength are input to different ports of the AWG and output to different ports of the AWG. For example, when the AWG receives an optical signal having a wavelength of 1311 nm through the right port 1, the AWG may send an optical signal through the left port 6. When the AWG receives an optical signal having a wavelength of 1311 nm through the right port 2, the AWG may send an optical signal through the left port 5. When the AWG receives an optical signal having a wavelength of 1311 nm through the right port 3, the AWG may send an optical signal through the left port 4.

[0089] FIG. 12 is a diagram of a BBU used for CWDM networking according to an embodiment of the present application. As shown in FIG. 12, the optical signals generated by the first laser, the second laser, and the third laser are output by using the lower output port of the corresponding SW after being modulated by the corresponding MOD, and are sent to the AAU through the AWG and the first R port. The AAU sends three optical signals to three optical modules respectively through the MUX. The 1271 nm, 1291 nm, and 1331 nm optical signals generated by the three optical modules in the AAU are combined into an optical fiber through the MUX and sent to the first R port through the optical fiber. After receiving the optical signals from the AAU, the first R port sends the optical signals to the AWG. FIG. 13 shows another route mapping table of the AWG according to an embodiment of the present application. The AWG may send three optical signals to three PDs respectively based on the route mapping table of FIG. 13. For example, when the AWG receives an optical signal having a wavelength of 1311 nm through its right port 3 , the AWG may send the optical signal through its left port 4 .

[0090] FIG. 14 is a diagram of a BBU used for BiDi single-fiber bidirectional networking according to an embodiment of the present application. As shown in FIG. 14, the optical signals generated by the first laser and the second laser are output by using the upper output port of the corresponding SW after being modulated by the corresponding MOD, and then are sent to the AAU through the corresponding T port after being combined through the corresponding MUX. The optical signal generated by the third laser is output through the lower output port of the corresponding SW after being modulated by the corresponding MOD, and is sent to the corresponding optical module in the AAU through the AWG and the first R port. The optical signal is received by using a wide spectrum after the optical signal is processed by a low-pass filter in the optical module included in the AAU. The AAU sends the 1271 nm optical signals, specifically 1271-1, 1271-2, and 1271-3, to the first T port, the first R port, and the second T port in the BBU, respectively. After receiving the optical signals from the AAU, the first R port sends the optical signals to the AWG. After receiving the optical signal from the AAU, the first T port and the second T port respectively send the optical signal to the AWG through the first MUX and the second MUX. Figure 15 shows yet another route mapping table of the AWG according to an embodiment of the present application. The AWG can respectively send three optical signals to three PDs based on the route mapping table of Figure 15. For example, when the AWG receives an optical signal with a wavelength of 1311 nm through the right port 3, the AWG can send an optical signal through the left port 4. For detailed descriptions of 1271-1, 1271-2, and 1271-3, please refer to the related descriptions of 1311-1, 1311-2, and 1311-3. Details will not be described again in this specification.

[0091] FIG. 16 is a diagram of yet another BBU structure according to an embodiment of the present application. As shown in FIG. 16, the lasers form a laser array and are integrated on a separate chip. The MOD, SW, and PD are integrated on a silicon photonic chip. The AWG and MUX are separate components. The optical coupling between the lasers and the MOD is a fiber optic coupling. The optical coupling between the MOD and the SW is a waveguide coupling. The optical coupling between the AWG and the SW, between the AWG and the PD, and between the AWG and the MUX is a fiber optic coupling.

[0092] FIG. 17 is a diagram of yet another structure of BBU according to an embodiment of the present application. As shown in FIG. 17, the lasers form a laser array and are integrated on a separate chip. The MOD, SW, PD, AWG, and MUX are all integrated on a chip, which can be a silicon on insulator (SOI) and silicon nitride (SiN) heterogeneous integrated chip. The laser array can couple the optical signal to the SOI and SiN heterogeneous integrated chip by using an end coupler. The MOD, SW, and PD can be integrated in the silicon (Si) layer in the SOI and SiN heterogeneous integrated chip. The AWG, MUX, and end coupler can be integrated in the SiN layer in the SOI and SiN heterogeneous integrated chip. The optical coupling between the laser and the MOD is an optical fiber coupling. The optical coupling between the MOD and the SW is a waveguide coupling. The optical coupling between the AWG and the SW, between the AWG and the PD, and between the AWG and the MUX is a waveguide coupling.

[0093] It should be understood that FIGS. 16 and 17 are illustrative examples of the structure of the BBU, and do not constitute limitations on the structure of the BBU.

[0094] The BBU may be used in an access network device, and the access network device may further include an AAU. For the structure of the BBU in the access network device, please refer to Figures 5 to 10, 12, and 14. The structure of the AAU is not limited in this application. In some implementations, the structure of the AAU may be shown in Figure 10, 12, or 14.

[0095] The objectives, technical solutions and beneficial effects of the present invention are further described in detail in the above specific implementations. It should be understood that the above description is only a specific implementation of the present invention, and is not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made based on the technical solutions of the present invention shall fall within the protection scope of the present invention.

Claims

1. A baseband unit (BBU) including M lasers, M switches (SW), M photodetectors (PD), an arrayed-waveguide grating (AWG), M transmit ports, and M receive ports, where M is an integer equal to or greater than 2; The i-th laser is coupled to the input end of the i-th SW, the upper output end of the i-th SW is coupled to the i-th transmit port, and the AWG is separately coupled to the lower output ends of the M switch SWs, the M PDs, and the M receive ports, where i=1, 2,..., or M. Baseband unit BBU.

2. The BBU further comprises M-1 multiplexers MUX; The jth MUX is separately coupled to the upper output end of the jth SW, the jth transmit port, and the AWG, where j=1, 2, . . . , or M−1; The BBU of claim 1.

3. The BBU further comprises M modulators MOD; The i-th MOD is separately coupled to the i-th laser and the input end of the i-th SW; 3. The BBU according to claim 1 or 2.

4. each of the M transmit ports and the M receive ports is coupled to an optical fiber; The M lasers are configured to transmit optical signals to corresponding optical fibers through corresponding SWs and corresponding transmit ports; The M PDs are configured to receive optical signals from corresponding optical fibers through the AWGs and corresponding receive ports. The BBU of claim 1.

5. each of the M transmit ports and the M receive ports is coupled to an optical fiber; The jth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding SW, a corresponding MUX, and a corresponding transmit port; The Mth laser is configured to transmit an optical signal to a corresponding optical fiber through a corresponding SW and a corresponding transmit port; The M PDs are configured to receive optical signals from corresponding optical fibers through the AWGs and corresponding receive ports. The BBU according to claim 2.

6. each of the M transmit ports and the M receive ports is coupled to an optical fiber; the jth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding MOD, a corresponding SW, a corresponding MUX, and a corresponding transmit port; The Mth laser is configured to transmit an optical signal to a corresponding optical fiber through a corresponding MOD, a corresponding SW, and a corresponding transmit port; The M PDs are configured to receive optical signals from corresponding optical fibers through the AWGs and corresponding receive ports. The BBU according to claim 3.

7. the first receive port is coupled to the optical fiber; the M lasers are configured to transmit optical signals through corresponding SWs, the AWGs, and the first receiving ports to the optical fibers; the M PDs are configured to receive optical signals from the optical fiber through the AWG and the first receive port; 3. The BBU according to claim 1 or 2.

8. the first receive port is coupled to the optical fiber; the M lasers are configured to transmit optical signals to the optical fiber through a corresponding MOD, a corresponding SW, the AWG, and the first receive port; the M PDs are configured to receive optical signals from the optical fiber through the AWG and the first receive port; The BBU according to claim 3.

9. the jth transmit port and the first receive port are each coupled to an optical fiber; The jth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding SW, a corresponding MUX, and a corresponding transmit port; an Mth laser is configured to transmit an optical signal to a corresponding optical fiber through a corresponding SW, the AWG, and the first receiving port; a jth PD is configured to receive an optical signal from the corresponding optical fiber through the AWG, the MUX, and the jth transmit port; an Mth PD is configured to receive an optical signal from the corresponding optical fiber through the AWG and the first receive port; The BBU according to claim 2.

10. the jth transmit port and the first receive port are each coupled to an optical fiber; the jth laser is configured to send an optical signal to a corresponding optical fiber through a corresponding MOD, a corresponding SW, a corresponding MUX, and a corresponding transmit port; an Mth laser is configured to transmit an optical signal to a corresponding optical fiber through a corresponding MOD, a corresponding SW, the AWG, and the first receiving port; a jth PD is configured to receive an optical signal from the corresponding optical fiber through the AWG, the MUX, and the jth transmit port; an Mth PD is configured to receive an optical signal from the corresponding optical fiber through the AWG and the first receive port; The BBU according to claim 3.

11. 10. The BBU of claim 1, 2, 4, 5, 7, or 9, wherein the laser is a directly modulated laser DML.

12. 12. The BBU of claim 1, wherein the laser is a semiconductor laser.

13. An access network device comprising an active antenna unit AAU and a BBU according to any one of claims 1 to 12.

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