Radio frequency optical components and corresponding modules, and wireless transmission systems

Abstract

This disclosure provides, in the field of communications technology, an RF optical component, and corresponding modules and wireless transmission systems. The RF optical component includes a first filtering assembly, a second filtering assembly, an optical transmission assembly, and an optical detection assembly. Both the first and second filtering assemblies transmit light. The first filtering assembly further receives a first optical signal, reflects the first optical signal to a second port, and combines the transmitted light and the first optical signal for output. The first filtering assembly further receives a second optical signal, reflects the transmitted light signal in the second optical signal for output, and transmits the received light in the second optical signal. The second filtering assembly refracts the received light to the optical detection assembly. This disclosure provides an RF optical component, and by using this RF optical component in a HUB or RRU, it reduces the cost and complexity of the network architecture and solves the problem of reduced terminal pRRU rates.

Description

Cross-reference to Related Applications

[0001] This disclosure claims the priority of the following patent applications. (1) A Chinese patent application with application number 202310803054.0, titled "A Radio Frequency Optical Component, Corresponding Module, and Wireless Transmission System", filed with the Chinese Patent Office on June 3, 2023.

Technical Field

[0002] This disclosure relates to the field of communication technologies, and particularly to radio frequency (RF) optical components, corresponding modules, and wireless transmission systems.

Background Art

[0003] Among various communication methods, wireless communication is favored by people due to its advantages such as flexible deployment, convenient use, and wide coverage. The wide spread of mobile communication networks has brought great convenience to people's daily lives and strongly promoted the development of human society. As various new applications such as smart driving, smart transportation, smart healthcare, and industrial Internet gradually penetrate into people's lives, people's demands for wireless communication services continue to increase rapidly. In order to meet the needs of actual applications, wireless communication networks need to have higher bandwidth, lower latency, and larger capacity. Therefore, various wireless communication standards are solving the above problems by increasing the operating frequency band and expanding the spectrum width. For example, currently, the upper limit of the operating frequency band of 5G and WiFi6 / 7 has been raised to 7.5 GHz, and the real-time operating bandwidth has been expanded to 200 MHz, and may be further expanded to 500 MHz or even 1 GHz in the future.

[0004] With the full-scale commercialization of 5G, 5G pRRUs will be more widely deployed and applied to further expand coverage and improve the experience for wireless access users. A network architecture exists in existing technology as shown in Figure 1. The HUB and pRRU (Pico Remote Radio Unit) are connected using a digital optical module. Since the digital optical module transmits digital baseband signals, the pRRU needs to integrate a high-speed AD / DA converter to perform digital-to-analog conversion and an ASIC (Application Specific Integrated Circuit) module to complete the encoding and decoding of the baseband signal (shown in the black dashed box in Figure 1). The pRRU converts the digital signal transmitted from the HUB side into an analog signal by D / A conversion according to the 5G air interface protocol standard, further converts it into an RF signal by an RF processing unit, and finally transmits it via an antenna. Similarly, the pRRU connects the HUB and the pRRU by converting the analog signal received by the antenna into a digital signal via A / D conversion, encoding the digital signal into a baseband signal according to the relevant protocol, and finally modulating it to a digital optical module for transmission to the HUB. Based on a baseband bandwidth of 200 MHz, 4096 IFFT points, and a subcarrier spacing of 60 kHz, the sampling bit rate of the baseband I / Q sampling rate is 245.76 MHz. Based on a sampling bit rate of 15 bits, and adding control bits and encoding overhead, one 10 Gbps optical module is required for one pair of antennas. Currently, if a typical pRRU configuration is one or two pairs of transmit and receive antennas, one 10 Gbps or 25 Gbps optical module is required.

[0005] However, as 5G is widely applied in fields such as smart driving, smart transportation, smart healthcare, and industrial internet, the number of terminal accesses in various scenarios will increase significantly. Furthermore, with the development of 5G mobile communications, user rate demands are also gradually increasing. For example, when user experience rates reach 1 Gbps, peak rates reach 10 Gbps, the number of access terminals within a square kilometer reaches 1 million, traffic density reaches tens of Tbps / square kilometer, and end-to-end latency is required to be at the millisecond level, an upgrade of the application scenario is necessary. That is, the pRRU needs to provide greater terminal access capacity and uplink / downlink rates, in which case the number of transmit / receive antennas in the pRRU increases to 4, 8, or even 128 antennas. This necessitates the use of FPGAs / ASICs with more powerful processing capabilities and more AD / DA converters in the pRRU. The network architecture shown in Figure 1 can no longer be supported. In the case of multiple antennas, in order to ensure the uplink / downlink rate for each terminal, the baseband signal rate after processing by the AD / DA and ASIC needs to be changed from the original 10G to 20G, 40G, or even 80G. Therefore, it is necessary to select and match optical modules with the corresponding transmission rate according to the change in uplink / downlink rate, thereby forming the pRRU side architecture shown in Figure 2 or Figure 3. In other words, the transmission rate between the pRRU and the HUB can be improved by adding one or more optical modules to the pRRU or by replacing existing low-rate optical modules with faster single-channel rate optical modules. As the number of antennas in the pRRU increases, the number of required optical modules increases accordingly, and the rate also improves accordingly. However, since the connection between the HUB and the pRRU is made using digital optical modules, the pRRU will have a large number of baseband signal processing units integrated into it.As application scenarios change, the uplink / downlink rates of pRRUs improve significantly, necessitating the use of more FPGAs / ASICs, AD / DA chips, high-speed optical modules, etc., with greater processing power and number in pRRUs. This not only leads to a significant increase in equipment costs but also a substantial increase in the power consumption of a single device, resulting in a clear rise in late-stage operation and maintenance costs. Based on the pRRU architecture shown in Figure 2 or Figure 3, a star network topology can be adopted between the HUB and the pRRUs. As shown in Figure 4, if the connection between the HUB and the pRRUs is completed using the same wavelength set λ1 / λ2, one optical fiber must be used between the HUB and each pRRU, which leads to a significant increase in optical fiber usage. If there are many pRRUs in a particular direction or region, there is an architecture shown in Figure 5 that can further reduce optical fiber usage. That is, wavelength division multiplexing is used, with pairs of CWDM wavelength digital optical modules used in the HUB and pRRUs, distinguishing different pRRUs in this region by wavelength difference and achieving complete coverage of the wireless signal in that region. In this method, a wavelength division multiplexer (MUX) must be added to the HUB side to combine the wavelengths of multiple optical modules, and a demultiplexer (DeMUX) must be added in the deployment area close to the pRRU to complete wavelength demultiplexing before transmission to each pRRU. The architectures in Figures 4 and 5 require either a huge amount of optical fiber usage or the addition of multiplexing and demultiplexing devices. Such methods not only increase the cost of network deployment but also further increase the complexity of the network, making later maintenance and assurance work extremely difficult. Furthermore, when a tree topology structure is adopted, the only way to achieve connections between pRRUs is to use a cascading method of electrical domains, and the uplink / downlink rate of each class of pRRU on the link is limited by the uplink / downlink rate of the first class pRRU. The uplink / downlink rate decreases as the pRRU is of a lower class, and the rate drops significantly at the terminal pRRU.

[0006] In light of this, overcoming the shortcomings of the existing technology is a problem that urgently needs to be resolved in this field. [Overview of the Initiative]

[0007] The technical challenges that this disclosure aims to address are the high complexity of existing wireless network architectures, the inconvenience and high cost of late-stage maintenance, and the significant decrease in the rate of end-user pRRUs.

[0008] This disclosure employs the following technical solutions.

[0009] In a first embodiment, the Disclosure provides an RF optical component comprising a first filtering assembly 1, a second filtering assembly 2, an optical transmission assembly 3, and an optical detection assembly 4. The second filtering assembly 2, the first filtering assembly 1, and the optical transmission assembly 3 are coupled in this order. The optical transmission assembly 3 is used to generate transmitted light based on an electrical signal transmitted from the control port, and both the first filtering assembly 1 and the second filtering assembly 2 are used to transmit the transmitted light. The first filtering assembly 1 is further used to receive a first optical signal from the first port, reflect the first optical signal to the second port, and combine the transmitted light and the first optical signal together and output them to the second port. The first filtering assembly 1 is further used to receive the second optical signal from the second port, reflect the transfer optical signal in the second optical signal back to the first port and output it, and transmit the received optical signal in the second optical signal to the second filtering assembly 2. The second filtering assembly 2 is used to refract the received light to the photodetection assembly 4, and the photodetection assembly 4 is used to convert the received light into a received electrical signal output to the control port.

[0010] Preferably, the RF optical component further includes a first collimating assembly 5 and a second collimating assembly 6. The first collimating assembly 5 is located on the side of the first filtering assembly 1 away from the optical transmitting assembly 3 and is used to collimate the first optical signal and the second optical signal. The second collimating assembly 6 is provided between the second filtering assembly 2 and the optical transmitting assembly 3 and is used to collimate the transmitted light.

[0011] Preferably, the RF optical component further includes a first optical fiber 7, a second optical fiber 8, and a fixing sleeve 9. One end of the first optical fiber 7 is provided within the fixed sleeve 9 and used to form the first port of the RF optical component. One end of the second optical fiber 8 is provided within the fixed sleeve 9 and used to form the second port of the RF optical component.

[0012] Preferably, the RF optical component supports transmission and reception of wavelengths from 1270 nm to 1610 nm.

[0013] In a second embodiment, the Disclosure provides an optical transceiver module comprising a plurality of RF optical components described in the first embodiment. Multiple RF optical components are cascaded together. Here, the second port of the upper RF optical component is connected to the first port of the lower RF optical component. The lower-level RF optical component receives a first optical signal from the higher-level RF optical component, combines the first optical signal with its own transmitted light and outputs it to a second port, and is used to combine the transmitted light of each RF optical component via a plurality of RF optical components and output it as a total transmitted light. The higher-level RF optical component is used to receive a second optical signal from the lower-level RF optical component, receive the received light in the second optical signal, and output the transferred light signal in the second optical signal to the first port. Here, the first port of the terminal RF optical component is used to receive the total received light, and the total received light is decoupled and received via multiple RF optical components. Here, the total transmitted light is output from the first port of the terminal RF optical component, and the total received light is received by the second port of the terminal RF optical component.

[0014] Preferably, the wavelengths of the transmitted light from each RF optical component are different, and the wavelengths of the received light from each RF optical component are different.

[0015] In a third aspect, the Disclosure provides a multiport forwarding module comprising an uplink forwarding module, a plurality of ADC / DAC modules, and an optical transceiver module as described in the second aspect. Each port of the uplink transfer module is connected to the corresponding control port of the optical transceiver module via the corresponding ADC / DAC module. The uplink transfer module is used to receive the downlink baseband signal from the baseband processing module and convert the downlink baseband signal into each downlink digital signal. The corresponding ADC / DAC module is used to convert the corresponding downlink digital signal into a transmit electrical signal. The optical transceiver module is used to output the total transmit light based on each transmit electrical signal. The optical transceiver module is further used to receive total received light and convert the total received light into individual received electrical signals. The corresponding ADC / DAC module is used to convert the received electrical signals into corresponding uplink digital signals. The uplink transfer module is used to convert the uplink digital signals into uplink baseband signals and transfer the uplink baseband signals to the baseband processing module.

[0016] In a fourth embodiment, the Disclosure provides a remote RF module including a downlink forwarding module and an optical transceiver module as described in the second embodiment. Each port of the downlink transfer module is connected to each control port of the optical transceiver module. The optical transceiver module is used to receive the total transmitted light from the multiport transfer module and to convert the total transmitted light into a downlink RF signal. The downlink transfer module is used to transmit each downlink RF signal to the corresponding terminal. The downlink transfer module is further used to receive the uplink RF signal from the terminal. The optical transceiver module is used to convert the uplink RF signal into total transmit light and transmit the total transmit light to the multiport transfer module.

[0017] In a fifth embodiment, the Disclosure provides a wireless transmission system including a baseband processing module, a multiport forwarding module, and a remote RF module. Here, the multiport forwarding module is the multiport forwarding module described in the third embodiment, and / or the remote RF module is the remote RF module described in the fourth embodiment. The multiport forwarding module and the remote RF module are connected using a single optical fiber.

[0018] Preferably, the wavelength of each received light from the multiport transfer module matches the wavelength of each transmitted light from the remote RF module, and the wavelength of each transmitted light from the multiport transfer module matches the wavelength of each received light from the remote RF module.

[0019] Compared with the existing technologies, the beneficial effects of the embodiments of the present disclosure are as follows: providing an RF optical component that realizes self - contained multiplexing and demultiplexing, and by using the RF optical component in a corresponding multi - port transfer module or remote RF module, input and output at the same port for multiple wavelengths are realized, thereby eliminating the need to use a wavelength - division multiplexer, reducing the cost of the network architecture, and enabling the connection between multi - port transfer modules or remote RF modules with only a single optical fiber, thereby reducing the complexity of the network architecture. For each RRU, only the corresponding demultiplexing and multiplexing are performed inside, and the rate of the transmitted optical signal is not changed, so the rate consistency of each level of RRU can be guaranteed, and the problem of the rate reduction of the terminal pRRU is solved.

Brief Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present disclosure or the existing technologies, the drawings necessary for use in the following description of the embodiments or the existing technologies will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and those skilled in the art can also obtain other drawings based on these drawings without creative labor.

[0021] [Figure 1] It is a schematic diagram of the architecture of a wireless transmission system in the existing technology provided by the embodiments of the present disclosure. [Figure 2] It is a schematic diagram of the architecture of an RRU in a wireless transmission system in the existing technology provided by the embodiments of the present disclosure. [Figure 3] It is a schematic diagram of the architecture of an RRU in another wireless transmission system in the existing technology provided by the embodiments of the present disclosure. [Figure 4] It is a schematic diagram of the connection between a HUB and an RRU in a wireless transmission system in the existing technology provided by the embodiments of the present disclosure. [Figure 5]This is a schematic diagram of the connection between a HUB and an RRU in a wireless transmission system in another existing technology provided by an embodiment of this disclosure. [Figure 6] This is a schematic diagram of an RF optical component provided by an embodiment of the disclosure. [Figure 7] This is a schematic diagram of yet another RF optical component provided by embodiments of the present disclosure. [Figure 8] This is a schematic diagram of yet another RF optical component provided by embodiments of the present disclosure. [Figure 9] This is a schematic diagram of another RF optical component provided by an embodiment of the disclosure. [Figure 10] This is a schematic diagram of a functional circuit in an RF optical component provided by an embodiment of this disclosure. [Figure 11] This is a schematic diagram of an optical transceiver module provided by an embodiment of the disclosure. [Figure 12] This is a schematic diagram of a multiport forwarding module provided by the embodiments of this disclosure. [Figure 13] This is a schematic diagram of a remote RF module provided by the embodiments of this disclosure. [Figure 14] This is a schematic diagram of a wireless transmission system provided by an embodiment of the disclosure. [Figure 15] This is a schematic diagram showing the connection between a HUB and an RRU in a wireless transmission system provided by an embodiment of this disclosure.

[0022] In all drawings, the same reference numeral is used to indicate the same element or structure. [Modes for carrying out the invention]

[0023] To further clarify the purpose, technical solutions, and advantages of this disclosure, the disclosure will be described in more detail below, in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and do not limit the disclosure.

[0024] In the description of this disclosure, the orientations or positional relationships indicated by terms such as “inside,” “outside,” “vertical,” “horizontal,” “up,” “down,” “top,” and “bottom” are based on the orientations or positional relationships shown in the drawings and are merely for the convenience of describing this disclosure. They do not require that this disclosure be constructed and operated in a particular orientation, and therefore should not be understood as limitations on this disclosure.

[0025] In this disclosure, terms such as “First,” “Second,” etc., are used solely for illustrative purposes and should not be understood as suggesting or implying relative importance or implicitly specifying the number of technical features being referred to. Therefore, features limited by “First,” “Second,” etc., may explicitly or implicitly include one or more such features. In this description, unless otherwise specified, “multiple” means two or more.

[0026] In this disclosure, unless otherwise expressly provided and limited, the term “connection” should be understood broadly, for example, “connection” may be a fixed connection, a detachable connection, or an integral part of a connection; it may be a direct connection or an indirect connection via an intermediate medium; and the term “coupling” may be an electrical connection method that enables signal transmission.

[0027] Furthermore, the technical features of each embodiment of the present disclosure described below can be combined with each other, insofar as they do not conflict with each other.

[0028] Embodiment 1:

[0029] Embodiment 1 of the present disclosure provides an RF optical component comprising a first filtering assembly 1, a second filtering assembly 2, an optical transmission assembly 3, and an optical detection assembly 4, as shown in Figures 6 and 7. The second filtering assembly 2, the first filtering assembly 1, and the optical transmission assembly 3 are coupled in this order. The optical transmission assembly 3 is used to generate transmit light based on a transmit electrical signal from a control port. Both the first filtering assembly 1 and the second filtering assembly 2 are used to transmit the transmit light. The first filtering assembly 1 is further used to receive a first optical signal from a first port, reflect the first optical signal to a second port, and combine the transmit light and the first optical signal together and output them to the second port. The first filtering assembly 1 is further used to receive a second optical signal from a second port, reflect the transfer light signal in the second optical signal to the first port and output it, and transmit the received light in the second optical signal to the second filtering assembly 2. The second filtering assembly 2 is used to refract the received light to the optical detection assembly 4. The light detection assembly 4 is used to convert the received light into a received electrical signal that is output to the control port.

[0030] Here, the input ports λ1 and λ2 shown in Figure 6 are referred to as the first ports, and the output ports λ1, λ2, and λ3 shown in Figure 6 are referred to as the second ports. Assuming that the transmitted light is the first wavelength (λ3 in Figure 6) and the detected light is the second wavelength (λ6 in Figure 7), the first optical signal (λ1 and λ2 in Figure 6) does not contain light of the first wavelength (λ3) and the second wavelength (λ6), and the second optical signal (λ4, λ5, and λ6 in Figure 7) contains the second wavelength (λ6) but does not contain the first wavelength (λ3). The optical transmission assembly 3 is used to transmit light of the first wavelength. The optical detection assembly 4 is used to receive light of the second wavelength. The first filtering assembly 1 is used to transmit light of the first and second wavelengths and reflect light of other wavelengths. The second filtering assembly 2 is used to transmit light of the first wavelength and refract light of the second wavelength to the optical detection assembly 4.

[0031] The first filtering assembly 1 and the second filtering assembly 2 may be corresponding filters in terms of their product form, and transmission, refraction, or reflection of corresponding wavelengths is achieved by coating the filter surface with a corresponding film layer. The light transmission assembly 3 may be a laser in terms of its product form, and the light detection assembly 4 may be a photodetector in terms of its product form.

[0032] This embodiment enables the RF optical component itself to perform corresponding multiplexing and demultiplexing by integrating a filtering assembly within the RF optical component, thereby partially replacing the wavelength division multiplexer and enabling the realization of a multi-wavelength optical transceiver module by cascading each RF optical component. The optical transceiver module will be described in detail in Embodiment 2, so no further explanation is needed here. This eliminates the need for a wavelength division multiplexer or multiple transmission optical fibers, thereby reducing architectural costs.

[0033] In actual use, as shown in Figure 8, the RF optical component further includes a first collimating assembly 5 and a second collimating assembly 6. The first collimating assembly 5 is located on the side of the first filtering assembly 1 away from the optical transmitting assembly 3 and is used to collimate the first optical signal and the second optical signal. The second collimating assembly 6 is located between the second filtering assembly 2 and the optical transmitting assembly 3 and is used to collimate the transmitted light. The first collimating assembly 5 and the second collimating assembly 6 may, by embodiment, be lenses. The second collimating assembly 6 adjusts the focused light emitted from the optical transmitting assembly 3 to parallel light. The first collimating assembly 5 is used to adjust the first optical signal or the second optical signal from diffuse light to parallel light. The first collimating assembly 5 and the second collimating assembly 6 may, by embodiment, be collimating lenses.

[0034] In a schematic diagram showing a configuration closer to the corresponding component configuration in a specific application scenario, as shown in Figure 9, the RF optical component may further include a ceramic ferrule 10 for fixing the first collimating assembly 5 and the optical transmitting assembly 3. The RF optical component further includes a first optical fiber 7, a second optical fiber 8, and a fixing sleeve 9. One end of the first optical fiber 7 is provided within the fixing sleeve 9 and used to form a first port of the RF optical component. One end of the second optical fiber 8 is provided within the fixing sleeve 9 and used to form a second port of the RF optical component.

[0035] In a selective embodiment, the RF optical component supports transmission and reception of wavelengths from 1270 nm to 1610 nm.

[0036] In actual use, the RF optical component further includes corresponding functional circuits, as shown in Figure 10, including sample-and-hold and constant-current drive circuits consisting of a microcontroller, operational amplifier, field-effect transistor, and Miller current source, as well as an RF amplification circuit consisting of a broadband bias, RF amplifier, RF attenuator, RF detector, etc.

[0037] Here, the microcontroller is used to control each functional circuit of the RF optical component, and includes the following:

[0038] Backlight current sampling and automatic power control circuit: The backlight current of the laser is sampled from the output voltage of the mirror current source, compared with a preset reference voltage 1, and then the control voltage 1 output to the operational amplifier is adjusted, which in turn adjusts the gate voltage of the field-effect transistor to change the operating current of the laser and realize automatic control of the laser's emission power.

[0039] RF power sampling and automatic level control circuit: The RF detector samples the voltage it detects, compares it with a preset reference voltage 2, adjusts the control voltage 2 of the operational amplifier, and consequently adjusts the bias voltage of the RF attenuator, thereby changing the operating current of the RF attenuator and achieving automatic control of the output level of the RF receiver amplifier circuit.

[0040] Operational amplifier 1 is used to adjust the operating current of the laser by amplifying the output control voltage of the microcontroller by a constant ratio, then adjusting the gate voltage of the field-effect transistor, and thereby changing the current between the source and drain of the field-effect transistor. Operational amplifier 2 is used to adjust the output level by amplifying the output control voltage of the microcontroller by a constant ratio, then adjusting the control voltage of the RF attenuator, and thereby changing the attenuation amount of the attenuator.

[0041] Field-effect transistors are used as constant current source drive circuits for lasers, providing the laser with an operating current circuit and controlling the operating current flowing through the laser by the output voltage of an operational amplifier, thereby enabling adjustment of the transmitted optical power.

[0042] A Miller current source is used to sample the backlight current of a laser. The circuit consists of two identical transistors and their peripheral circuitry. One transistor is used to provide a reverse bias to the backlight diode. When the backlight diode generates a photocurrent under the backlight of the laser, the other transistor generates the same current as the current in the bias current path of the backlight diode. This current is converted to a voltage via a resistor, sampled by the A / D converter of a microcontroller, and used as a reference for monitoring and automatic power control of the laser's output optical power.

[0043] Low-noise amplifiers are used to amplify the weak RF signal received by the detector of an RF optical component into a large signal with low noise and relatively strong interference immunity. RF attenuators are used to adjust the output level of the low-noise amplifier and ensure output level stability. Power amplifiers are used to amplify the RF signal output by the RF attenuator to a certain power level, providing the capability to drive the terminal amplifier on the pRRU.

[0044] A directional coupler is used to couple a portion of the power amplifier's output signal to an RF detector. The RF detector converts the RF signal coupled via the power coupler into a DC voltage, which is then sampled by the microcontroller's A / D converter, compared to a predetermined reference voltage, and then adjusts the output voltage of the operational amplifier 2. By using this optical module in the pRRU, it is possible to save on ASICs and high-speed D / A-A / D conversion chips while still ensuring good signal indexing and relatively long transmission distances.

[0045] Embodiment 2:

[0046] Based on Embodiment 1, this embodiment further provides an optical transceiver module. As shown in Figure 11, the optical transceiver module includes a plurality of RF optical components described in Embodiment 1. The plurality of RF optical components are cascaded to one another. Here, the second port of the upper RF optical component is connected to the first port of the lower RF optical component. The lower RF optical component receives a first optical signal from the upper RF optical component, combines the first optical signal with its own transmitted light and outputs it to the second port, and is used to combine the transmitted light of each RF optical component via the plurality of RF optical components and output it as total transmitted light. The upper RF optical component receives a second optical signal from the lower RF optical component, receives the received light in the second optical signal, and is used to output the transferred light signal in the second optical signal to the first port. Here, the first port of the terminal RF optical component is used to receive the total received light, and the total received light is decoupled and received via the plurality of RF optical components. Here, the total transmitted light is output from the first port of the terminal RF optical component, and the total received light is received by the second port of the terminal RF optical component.

[0047] Here, the wavelength of the transmitted light from each RF optical component is different, and the wavelength of the received light from each RF optical component is also different. In Figure 11, port1 represents the first port of the corresponding RF optical component, and port2 represents the second port of the corresponding RF optical component. The terms "upper RF optical component" and "lower RF optical component" both refer to two interconnected RF optical components. Taking the optical transceiver module shown in Figure 11 as an example, the second port of RF optical component 1 is connected to the first port of RF optical component 2. Therefore, for RF optical component 1 and RF optical component 2, RF optical component 1 is the upper RF optical component, and RF optical component 2 is the lower RF optical component. On the other hand, the second port of RF optical component 2 is further connected to the first port of RF optical component 3. Therefore, for RF optical component 2 and RF optical component 3, RF optical component 2 is the upper RF optical component, and RF optical component 3 is the lower RF optical component.

[0048] The following describes the process of combining transmitted light between multiple interconnected RF optical components, using the optical transceiver module shown in Figure 11 as an example. Here, the transmitted light of RF optical component 1 is λ1, and λ1 is transmitted to the lower-level RF optical component, i.e., RF optical component 2. RF optical component 2 combines λ1 with its own transmitted light λ2 to obtain λ1~λ2. λ1~λ2 is input to RF optical component 3, which combines λ1~λ2 with its own transmitted light λ3 and outputs λ1~λ3, ... and so on. RF optical component n combines λ1~λn-1 with its own transmitted light λn and outputs λ1~λn, thereby realizing multi-wavelength transmission via the cascaded connection of multiple RF optical components.

[0049] Contrary to the multi-wavelength transmission direction, the multi-wavelength received light λn+1 to λ2n is input from the second port of RF optical component n. The received light of the RF optical component is λ2n, and the RF optical component demultiplexes λn+1 to λ2n, receives λ2n, and transmits λn+1 to λ2n-1 to the higher-level RF optical component, i.e., RF optical component n-1. The light received by RF optical component n-1 is λ2n-1. That is, RF optical component n-1 demultiplexes the light from λn+1 to λ2n-1, receives λ2n-1, and transmits λn+1 to λ2n-2 to RF optical component n-2, ... and so on. The light ultimately transmitted to RF optical component 2 is λn+1 to λn+2. Of these, λn+2 is received by RF optical component 2, and the light that finally reaches RF optical component 1 and is received by it is λn+1. Thus, multi-wavelength reception is achieved through the cascading connection of multiple RF optical components.

[0050] In one selective embodiment, the number of RF optical components is eight. The transmitted optical wavelengths of the eight RF optical components are 1270 nm, 1290 nm, 1310 nm, 1330 nm, 1350 nm, 1370 nm, 1390 nm, and 1410 nm, respectively, and the received optical wavelengths of the eight RF optical components are 1470 nm, 1490 nm, 1510 nm, 1530 nm, 1550 nm, 1570 nm, 1590 nm, and 1610 nm, respectively. Alternatively, the transmitting wavelengths of the eight RF optical components are 1470nm, 1490nm, 1510nm, 1530nm, 1550nm, 1570nm, 1590nm, and 1610nm, respectively, and the receiving wavelengths of the eight RF optical components are 1270nm, 1290nm, 1310nm, 1330nm, 1350nm, 1370nm, 1390nm, and 1410nm, respectively.

[0051] Embodiment 3:

[0052] Based on Embodiment 2, this embodiment further provides a multiport forwarding module. As shown in Figure 12, it includes an uplink forwarding module, a plurality of ADC / DAC modules, and the optical transceiver module described in Embodiment 2. Here, the uplink forwarding module typically includes a digital optical module and an ASIC module in actual use. The multiport forwarding module may be represented as a HUB in form.

[0053] Each port of the uplink transfer module is connected to the corresponding control port of the optical transceiver module via the corresponding ADC / DAC module. The uplink transfer module is used to receive the downlink baseband signal from the baseband processing module and convert the downlink baseband signal into each downlink digital signal. The corresponding ADC / DAC module is used to convert the corresponding downlink digital signal into a transmit electrical signal. The optical transceiver module is used to output the total transmit light based on each transmit electrical signal. The optical transceiver module is further used to receive the total received light and convert the total received light into each received electrical signal. The corresponding ADC / DAC module is used to convert the received electrical signal into the corresponding uplink digital signal. The uplink transfer module is used to convert the uplink digital signal into an uplink baseband signal and transfer the uplink baseband signal to the baseband processing module.

[0054] In actual application scenarios, the uplink transfer module includes a digital optical module and an ASIC module. The ASIC module is used to convert the uplink digital signal into an uplink baseband signal. The digital optical module is used to transfer the uplink baseband signal to the baseband processing module.

[0055] According to the embodiment of this model, it is possible to achieve multiplexed optical transmission and reception without the need for wavelength division multiplexers and wavelength demultiplexers, thereby reducing manufacturing costs. Furthermore, it is possible to connect to remote RF modules via a single optical fiber, facilitating later network operation and maintenance and saving operation and maintenance costs. In addition, since wavelength division multiplexers and wavelength demultiplexers are unnecessary, a basis for miniaturization of multiport forwarding modules is provided.

[0056] Embodiment 4:

[0057] Based on Embodiment 2, this embodiment further provides a remote RF module, which includes a downlink forwarding module and an optical transceiver module as described in Embodiment 2, as shown in Figure 13. Here, the downlink forwarding module typically includes an antenna module and an RF processing module in actual use, and the antenna module includes one or more antennas. The remote RF module may be represented morphologically as an RRU.

[0058] Each port of the downlink transfer module is connected to each control port of the optical transceiver module. The optical transceiver module is used to receive the total transmitted light from the multiport transfer module and convert the total transmitted light into downlink RF signals. The downlink transfer module is used to transmit each downlink RF signal to the corresponding terminal. The downlink transfer module is further used to receive uplink RF signals from the terminal. The optical transceiver module is used to convert the uplink RF signals into total transmitted light and transmit the total transmitted light to the multiport transfer module.

[0059] In actual application scenarios, the downlink forwarding module includes an RF processing module and an antenna module. The RF processing module is used to convert the uplink RF signal into total transmitted light. The antenna module is used to transmit the total transmitted light to the multiport forwarding module.

[0060] According to the implementation of this embodiment, there is no need to use ADC / DAC modules and ASICs, thereby reducing manufacturing costs, providing a basis for miniaturization of remote RF modules, and enabling connection to multi-port forwarding modules via a single optical fiber, thereby facilitating later network operation and maintenance and saving operation and maintenance costs.

[0061] Embodiment 5:

[0062] Based on Embodiments 3 and 4, this embodiment further provides a wireless transmission system. As shown in Figure 14, it includes a baseband processing module, a multiport forwarding module, and a remote RF module. Here, the multiport forwarding module is the multiport forwarding module described in Embodiment 3, and / or the remote RF module is the remote RF module described in Embodiment 4. The multiport forwarding module and the remote RF module are connected using a single optical fiber.

[0063] Here, the wavelength of each received light of the multiport transfer module matches the wavelength of each transmitted light of the remote RF module, and the wavelength of each transmitted light of the multiport transfer module matches the wavelength of each received light of the remote RF module. For example, in one selective embodiment, the wavelengths of each received light of the multiport transfer module are 1470 nm, 1490 nm, 1510 nm, 1530 nm, 1550 nm, 1570 nm, 1590 nm, and 1610 nm, respectively. The wavelengths of each transmitted light of the multiport transfer module are 1270 nm, 1290 nm, 1310 nm, 1330 nm, 1350 nm, 1370 nm, 1390 nm, and 1410 nm, respectively.

[0064] What needs to be explained here is that while Figure 14 is a schematic diagram of a wireless transmission system including a baseband processing module, a multiport transfer module described in Embodiment 3, and a remote RF module described in Embodiment 4, in actual use, it is equally feasible to configure a wireless transmission system using a multiport transfer module from existing technology and a remote RF module described in Embodiment 4 (as shown in Figure 13), or to configure a wireless transmission system using a multiport transfer module from Embodiment 3 and a remote RF module from existing technology (as shown in Figure 12).

[0065] According to the implementation of this embodiment, there is no need for the remote RF module to perform D / A conversion and encoding processing on the RF signal. Instead, the RF signal received by the antenna is transmitted to the multiport transfer module via the multitransceiver module. The multitransceiver optical module in the multiport transfer module demodulates the RF signal, converts it to a digital signal via an ADC / DAC (i.e., an ADC / DAC module), and then converts it to a baseband signal compliant with the 5G protocol through ASIC processing. Finally, it is transmitted back to the baseband processing module via the digital optical module of the uplink port in the multiport transfer module, and vice versa.

[0066] Here, the multiport forwarding module will be described using a HUB in subsequent embodiments, the remote RF module will be described using a pRRU in subsequent embodiments, and the baseband processing module will be described using a BBU (Building Baseband Unit) in subsequent embodiments.

[0067] Compared to existing technologies (Figures 5 and 3), this architecture saves multiplexers / demultiplexers on both the HUB and pRRU sides, and relocates functional components such as ASICs and high-speed AD / DA converters from the pRRU device to the HUB side. Each pRRU can share baseband processing units such as ASICs and high-speed AD / DA converters on the HUB side, significantly reducing the cost and power consumption of the pRRU and saving on later operating costs. As shown in Figure 14, the existing ASICs and ADC / DACs in the pRRU have already been removed.

[0068] At the same time, the HUB can improve the utilization efficiency of the uplink port by uniformly adjusting and allocating bandwidth resources to each pRRU based on the number of terminals accessed by different pRRUs and their bandwidth requirements. Based on the coverage range and the number of cascaded connections, the corresponding wavelengths and quantities of optical modules are selected, and the optical path cascading method enables longer-distance coverage and saves more optical fiber resources compared to a star configuration. Since each class of pRRU is distinguished by optical wavelength, the transmission bandwidth and power are basically the same, resolving the situation where the rate of later class pRRUs is lower than the rate of earlier class pRRUs in cascaded connection coverage.

[0069] In a selective embodiment, as shown in Figure 15, both the multiport forwarding module and the remote RF module may use an 8-transmit 8-receive optical transceiver module. Here, λ1 to λ8 are 1270nm, 1290nm, 1310nm, 1330nm, 1350nm, 1370nm, 1390nm, and 1410nm, respectively, and λ9 to λ16 are 1470nm, 1490nm, 1510nm, 1530nm, 1550nm, 1570nm, 1590nm, and 1610nm, respectively.

[0070] The foregoing describes only preferred embodiments of the Disclosure and does not limit it. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the Disclosure should all be within the scope of protection of the Disclosure. [Explanation of Symbols]

[0071] 1: First filtering assembly 2: Second filtering assembly 3: Optical transmission assembly 4: Photodetector assembly 5: First Collimated Assembly 6: Second Collimated Assembly 7: First optical fiber 8: Second optical fiber 9: Fixed sleeve 10: Ceramic ferrule

Claims

1. A radio frequency (RF) optical component comprising a first filtering assembly (1), a second filtering assembly (2), an optical transmission assembly (3), and an optical detection assembly (4), The second filtering assembly (2), the first filtering assembly (1), and the optical transmission assembly (3) are connected in this order. The optical transmission assembly (3) is used to generate transmitted light based on a transmitted electrical signal from the control port, and both the first filtering assembly (1) and the second filtering assembly (2) are used to transmit the transmitted light. The first filtering assembly (1) is further used to receive a first optical signal from the first port, reflect the first optical signal to the second port, and combine the transmitted light and the first optical signal together and output them to the second port. The first filtering assembly (1) further receives the second optical signal from the second port, reflects the transfer optical signal in the second optical signal back to the first port and outputs it, and transmits the received optical signal in the second optical signal to the second filtering assembly (2). The second filtering assembly (2) is used to refract the received light to the photodetector assembly (4), and the photodetector assembly (4) is used to convert the received light into a received electrical signal output to the control port. A radio frequency optical component characterized by the following features.

2. The RF optical component further includes a first collimating assembly (5) and a second collimating assembly (6), The first collimating assembly (5) is located on the side of the first filtering assembly (1) away from the optical transmitting assembly (3) and is used to collimate the first optical signal and the second optical signal. The second collimating assembly (6) is provided between the second filtering assembly (2) and the optical transmitting assembly (3) and is used to collimate the transmitted light. The radio frequency optical component according to feature 1.

3. The RF optical component further includes a ceramic ferrule (10), which is used to secure the optical transmitting assembly and the first collimating assembly (5). The radio frequency optical component according to feature 2.

4. The first collimating assembly (5) and / or the second collimating assembly (6) are lenses. The radio frequency optical component according to feature 2.

5. The RF optical component further includes a first optical fiber (7), a second optical fiber (8), and a fixing sleeve (9), One end of the first optical fiber (7) is provided within the fixed sleeve (9) and is used to form the first port of the RF optical component. One end of the second optical fiber (8) is provided within the fixed sleeve (9) and is used to form the second port of the RF optical component. The radio frequency optical component according to feature 1.

6. The RF optical component supports transmission and reception of wavelengths from 1270 nm to 1610 nm. The radio frequency optical component according to feature 1.

7. The first filtering assembly (1) and / or the second filtering assembly (2) are filters. The RF optical component according to any one of claims 1 to 6.

8. The optical transmission assembly (3) is a laser. A radio frequency optical component according to any one of claims 1 to 6.

9. The aforementioned light detection assembly (4) is a photodetector. A radio frequency optical component according to any one of claims 1 to 6.

10. An optical transceiver module comprising a plurality of RF optical components according to any one of claims 1 to 9, Multiple RF optical components are cascaded together, where the second port of the upper RF optical component is connected to the first port of the lower RF optical component. The lower RF optical component receives a first optical signal from the higher RF optical component, combines the first optical signal with its own transmitted light and outputs it to a second port, and is used to combine the transmitted light of each RF optical component via a plurality of RF optical components and output it as a total transmitted light. The upper RF optical component is used to receive a second optical signal from the lower RF optical component, receive the received light in the second optical signal, and output the transmitted light signal in the second optical signal to the first port, where the first port of the terminal RF optical component is used to receive the total received light, and the total received light is decoupled and received via a plurality of RF optical components, where the total transmitted light is output from the first port of the terminal RF optical component, and the total received light is received by the second port of the terminal RF optical component. An optical transceiver module characterized by the following features.

11. Each RF optical component transmits light at a different wavelength, and each RF optical component receives light at a different wavelength. The optical transceiver module according to feature 10.

12. The number of RF optical components is eight. The optical transceiver module according to feature 10.

13. The transmitting wavelengths of the eight RF optical components are 1270 nm, 1290 nm, 1310 nm, 1330 nm, 1350 nm, 1370 nm, 1390 nm, and 1410 nm, respectively, and the receiving wavelengths of the eight RF optical components are 1470 nm, 1490 nm, 1510 nm, 1530 nm, 1550 nm, 1570 nm, 1590 nm, and 1610 nm, respectively, and The transmission wavelengths of the eight RF optical components are 1470 nm, 1490 nm, 1510 nm, 1530 nm, 1550 nm, 1570 nm, 1590 nm, and 1610 nm, respectively, and the reception wavelengths of the eight RF optical components are 1270 nm, 1290 nm, 1310 nm, 1330 nm, 1350 nm, 1370 nm, 1390 nm, and 1410 nm, respectively. The optical transceiver module according to feature 12.

14. A multiport transfer module comprising an uplink transfer module, a plurality of ADC / DAC modules, and an optical transceiver module according to any one of claims 10 to 13, Each port of the uplink transfer module is connected to the corresponding control port of the optical transceiver module via the corresponding ADC / DAC module. The uplink transfer module is used to receive the downlink baseband signal from the baseband processing module and convert the downlink baseband signal into each downlink digital signal; the corresponding ADC / DAC module is used to convert the corresponding downlink digital signal into a transmit electrical signal; and the optical transceiver module is used to output the total transmit light based on each transmit electrical signal. The optical transceiver module is further used to receive total received light and convert the total received light into individual received electrical signals; the corresponding ADC / DAC module is used to convert the received electrical signals into corresponding uplink digital signals; and the uplink transfer module is used to convert the uplink digital signals into uplink baseband signals and transfer the uplink baseband signals to the baseband processing module. A multi-port forwarding module characterized by the following features.

15. The aforementioned uplink transfer module includes a digital optical module and an ASIC module. The ASIC module is used to convert the uplink digital signal into an uplink baseband signal. The digital optical module is used to transfer the uplink baseband signal to the baseband processing module. The multiport forwarding module according to feature 14.

16. A remote RF module comprising a downlink transfer module and an optical transceiver module according to any one of claims 10 to 13, Each port of the downlink transfer module is connected to each control port of the optical transceiver module. The optical transceiver module is used to receive the total transmitted light from the multiport transfer module and convert the total transmitted light into a downlink RF signal, and the downlink transfer module is used to transmit each downlink RF signal to the corresponding terminal. The downlink transfer module is further used to receive the uplink RF signal from the terminal, and the optical transceiver module is used to convert the uplink RF signal into total transmit light and transmit the total transmit light to the multiport transfer module. A remote RF module characterized by the following features.

17. The downlink transfer module includes an RF processing module and an antenna module. The RF processing module is used to convert the uplink RF signal into total transmitted light. The antenna module is used to transmit the total transmitted light to the multiport transfer module. The remote RF module according to feature 16.

18. A wireless transmission system including a baseband processing module, a multiport forwarding module, and a remote RF module, The multiport transfer module is the multiport transfer module described in claim 14 or claim 15, and / or the remote RF module is the remote RF module described in claim 16 or claim 17. The multi-port forwarding module and the remote RF module are connected using a single optical fiber. A wireless transmission system characterized by the following features.

19. The wavelength of each received light from the multiport transfer module matches the wavelength of each transmitted light from the remote RF module, and the wavelength of each transmitted light from the multiport transfer module matches the wavelength of each received light from the remote RF module. The wireless transmission system according to feature 18.

20. The receiving optical wavelengths of the multiport transfer module are 1470 nm, 1490 nm, 1510 nm, 1530 nm, 1550 nm, 1570 nm, 1590 nm, and 1610 nm, respectively, and the transmitting optical wavelengths of the multiport transfer module are 1270 nm, 1290 nm, 1310 nm, 1330 nm, 1350 nm, 1370 nm, 1390 nm, and 1410 nm, respectively. The wireless transmission system according to feature 18.

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