Distributed antenna system for 5G-specific networks

Abstract

We provide a distributed antenna system for 5G-specific networks, consisting of Access Units and Remote Units, which efficiently utilize specific frequency bands to provide high-quality communication services within buildings or specific locations. [Solution] The distributed antenna system for 5G-specific networks consists of an access unit 1 and a remote unit 5. The access unit 1 uses a frequency band of 4600 to 4900 MHz, and the remote unit 5 is divided into a first type of remote unit 5 that supports a frequency band of 4600 to 4800 MHz and a second type of remote unit 5 that supports a frequency band of 4700 to 4900 MHz. Either the first type or the second type of remote unit 5 is selected and installed depending on the location of the building.

Description

Technical Field

[0001] The present invention relates to a distributed antenna system for a 5G specialized network. More specifically, it relates to an access unit and a remote unit that efficiently utilize a specific frequency band to provide high-quality communication services within a building or a specific location, and which constitute a distributed antenna system for a 5G specialized network.

Background Art

[0002] 5G communication networks enable ultra-high-speed data transmission, ultra-low latency, and large-scale device connection, and are currently being utilized in various industrial fields. 5G specialized networks enhance security and stability by constructing customized communication networks tailored to enterprises or specific facilities. In such specialized networks, it is important to optimize communication quality within a building by utilizing a specific frequency band.

[0003] In conventional communication systems, when using a single frequency range, there is a risk of degradation in communication quality due to interference within that range. To address this problem, a method is required to effectively utilize various frequency bands, minimize interference, and achieve the best performance in each band. In particular, in a communication system based on a 5G specialized network, it is necessary for the access unit and the remote unit to cooperate and operate in a specific band to optimize the utilization of frequency resources and improve service quality.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In 5G-specific network communication systems, signal transmission across various frequency bands is crucial for providing high-speed data transmission and low latency. However, in conventional communication systems, mutual interference can occur and signal quality can degrade when multiple remote units operate using the same frequency band. This interference problem can become even more severe, especially when multiple remote units use the same frequency band within other buildings or structures.

[0005] Furthermore, the required frequency bands vary depending on the location and building, potentially posing a challenge to the effective utilization of frequency resources. Conventional systems have been unable to effectively address these diverse requirements, resulting in difficulties in efficient frequency resource management and the provision of optimized communication services. Therefore, the problem that this invention aims to solve is to provide a 5G-specific network communication system that minimizes interference by dividing the frequency band between access units and remote units, provides high-quality communication services, and optimizes frequency selection in particular to reduce interference between multiple buildings. Another problem that this invention aims to solve is to propose a system that enables flexible communication services tailored to user needs by selectively supporting various frequency bandwidths according to the characteristics of the building where the remote unit is installed and the needs of the company. [Means for solving the problem]

[0006] This invention provides a 5G-specific network communication system composed of an access unit and a remote unit. In this 5G-specific network communication system, the access unit has a frequency band of 4600-4900MHz, and the remote unit is divided into a first type of remote unit (Type A) that supports a frequency band of 4600-4800MHz and a second type of remote unit (Type B) that supports a frequency band of 4700-4900MHz. With this configuration, by selecting and installing the appropriate type of remote unit according to the location and requirements of the building, efficient utilization of frequency resources and minimization of interference become possible. The access unit also includes the function of transmitting and receiving RF signals with the base station, converting the RF signal to a digital signal, and further converting that signal to an optical signal. On the other hand, the remote unit has the function of converting the optical signal to a digital signal and converting the digital signal back to an RF signal, and includes a high-power amplifier and a bandpass filter to remove noise to ensure stable signal transmission. Furthermore, in response to the diverse frequency bandwidth requirements of companies, the remote unit can selectively lease bandwidth from 40MHz to 100MHz and provide services. Furthermore, when the remote unit is installed within a specific building, the bandwidth of the digital filter is set according to the frequency band. [Effects of the Invention]

[0007] According to embodiments of the present invention, by efficiently distributing the frequency band between the access unit and the remote unit, minimizing frequency interference, and selectively installing the type of remote unit (Type A, Type B) according to the location of each building, it is possible to provide optimized wireless services. Furthermore, when the remote unit is installed inside a building, it includes a function to automatically recognize the frequency band and perform frequency filtering, allowing for flexible use of various frequency bands according to the needs of the company. This enables the provision of high-quality communication services while preventing mutual interference, and by efficiently utilizing frequency resources, the stability and performance of the communication system can be significantly improved. In addition, by including a control device and a power supply device that effectively control the system between the access unit and the remote unit, the reliability and performance of the communication system can be further guaranteed. This system has the particular advantage of minimizing interference between buildings and providing stable services both inside and outside large buildings. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram illustrating a distributed antenna system for a 5G-specific network according to an embodiment of the present invention.

[0009] [Figure 2] This is a block diagram illustrating the access unit of a distributed antenna system for a 5G-specific network according to an embodiment of the present invention.

[0010] [Figure 3] This is a block diagram illustrating a remote unit of a distributed antenna system for a 5G-specific network according to an embodiment of the present invention.

[0011] [Figure 4] This is a block diagram illustrating the amplification unit of a remote unit according to an embodiment of the present invention. [Modes for carrying out the invention]

[0012] The present invention and the technical problems to be solved by implementing it will become clearer from the preferred embodiments of the invention described below. The following embodiments are merely illustrative to illustrate the present invention and are not intended to limit the scope of the invention.

[0013] An embodiment of the present invention provides a distributed antenna system for a 5G-dedicated network, comprising an access unit 1 and a remote unit 5 for servicing a 5G-dedicated network. The access unit 1 has a frequency band of 4600 to 4900 MHz, and the remote unit 5, which communicates with the access unit 1, constitutes a dedicated network communication system divided into a first type of remote unit (Type A) that supports a frequency band of 4600 to 4800 MHz and a second type of remote unit (Type B) that supports a frequency band of 4700 to 4900 MHz. This configuration provides the present invention with the flexibility to select and install the type of remote unit 5 according to the building's location and environmental conditions.

[0014] As illustrated in Figure 1, access unit 1, which receives an RF signal from base station (B), converts it into an optical signal and transmits it to remote unit 5 via an optical cable. Access unit 1 receives radio waves with a bandwidth of 4600MHz to 4900MHz and converts them into an optical signal. Remote unit 5 receives the optical signal from access unit 1 via an optical cable. There are two types of remote unit 5: type A, which communicates using radio waves in the 4600MHz to 4800MHz bandwidth, and type B, which generates radio waves in the 4700MHz to 4900MHz bandwidth.

[0015] One building can be equipped with only Type A remote unit 5, while another nearby building can be equipped with only Type B remote unit 5. This reduces the overlap in frequency bands, making it less likely that radio waves generated in one building will affect another and cause interference. In the 300MHz band, excluding the central overlapping 100MHz (4700MHz~4800MHz), the remaining 100MHz (4600MHz~4700MHz, 4800MHz~4900MHz) can be used exclusively by each building. In this way, by having both shared and exclusive bands, it is possible to secure a certain amount of bandwidth while keeping the possibility of interference low. More important and high-performance signals can be transmitted using the exclusive band, and the remaining portion can be used in the overlapping band.

[0016] Multiple remote units 5 can be connected to one access unit 1. One remote unit 5 is connected to the access unit 1 via one optical cable, and by installing multiple remote units 5, multiple remote units 5 can be connected to the access unit 1 via multiple optical cables. Remote units 5 may also be connected in a cascaded manner. In addition to remote units 5 that are directly connected to the access unit 1 via optical cable, some remote units 5 may be connected to other remote units 5 and indirectly connected to the access unit 1.

[0017] The RF signal received by access unit 1 from base station (B) is transmitted to each remote unit 5 via optical cable, and the remote unit 5 converts it back into an RF signal and transmits it to the user device, thereby facilitating smooth communication between base station (B) and user devices. The distributed antenna system for a 5G-specific network according to an embodiment of the present invention can deliver the signal from base station (B) even to shaded areas within a building.

[0018] As shown in Figure 2, the access unit 1 of the distributed antenna system for a 5G-specific network according to an embodiment of the present invention may include an RF module 13, a first photon-optical conversion unit 15, a control unit 10, and a first power supply unit 19.

[0019] The RF module 13 is configured with a bandpass filter, amplifier, attenuator, etc., to appropriately adjust the magnitude of the signal received from base station B, remove noise, and allow only the necessary frequency band to pass through. The RF module 13 has two paths: an uplink and a downlink. Bandpass filters, amplifiers, attenuators, etc. may be installed along these paths. Multiple RF modules 13 can be installed, and one of the multiple RF modules 13 is connected to one of the multiple base stations B in a 1:1 correspondence. Since the access unit 1 supports the 4600-4900MHz frequency band, the bandpass filter of the RF module 13 is configured accordingly. Because 5G communication employs a time-division deadlock (TDD) method, the uplink and downlink paths are alternately enabled and disabled depending on the time.

[0020] The first electro-optical conversion unit 15 is configured to convert analog RF signals received from the RF module 13 into digital signals and perform electro-optical conversion in the downlink path. In the uplink path, it can convert optical signals received from the remote unit 5 into RF analog signals and transmit them to the RF module 13.

[0021] The plurality of RF modules 13 can be connected to the first electro-optical conversion unit 15. Signals input from the plurality of RF modules 13 to the first electro-optical conversion unit 15 are combined and converted into one optical signal. This optical signal is transmitted to the remote unit 5 connected to the access unit 1 via the optical cable 21. In the downlink path, signals from the plurality of base stations B are transmitted to the remote unit 5 through one optical cable 21. Similarly, in the uplink path, one optical signal is split into a plurality of RF signals by the first electro-optical conversion unit 15 and transmitted to the corresponding RF module 13. A plurality of optical cables 21 are connected to the first electro-optical conversion unit 15, and each optical cable 21 is connected to the corresponding remote unit 5.

[0022] The access unit 1 can include a control unit 10 and a first power supply unit 19. The control unit 10 monitors and controls the RF module 13 and the first electro-optical conversion unit 15 of the access unit 1, and the first power supply unit 19 can supply power to the RF module 13 and the first electro-optical conversion unit 15.

[0023] As shown in FIG. 3, the remote unit 5 of the distributed antenna system for a 5G specialized network according to an embodiment of the present invention is connected to the access unit 1 via the optical cable 21, and an optical switch 51 can be installed inside.

[0024] Four terminals are connected to the optical switch 51, and one of them is connected to the optical cable 21 connected to the access unit 1. Another one is connected to the optical cable 29 connected to another remote unit 5. Therefore, a remote unit not directly connected to the access unit 1 can also be indirectly connected to the access unit 1 via another directly connected remote unit's 5. The other terminals of the optical switch 51 can be connected to the second electro-optical conversion unit 55 via the optical multiplexer 53.

[0025] The distributed antenna system for a 5G-specific network according to an embodiment of the present invention is driven by a TDD (Temperature-Driven Deposition) method, so that the optical switch 51 can be switched to form uplink and downlink paths in accordance with time. A switching signal is generated by a control unit (not shown), and the optical switch 51 can be controlled according to the timing of switching between uplink and downlink.

[0026] During downlinking, the signal coming in from access unit 1 through optical cable 21 is supplied to second electro-to-optical conversion unit 55 via optical multiplexer 53. In the second electro-to-optical conversion unit 55, the optical signal is converted to an RF signal and supplied to amplification unit 60. The second electro-to-optical conversion unit 55 also outputs an optical signal, which is supplied to optical cable 29 connected to other remote units via optical multiplexer 53 and optical switch 51. In this way, the signal transmitted from access unit 1 can reach remote unit 5 directly connected to access unit 1 and other remote units connected to remote unit 5 by optical cable 29.

[0027] Similarly, during uplinking, an optical signal is transmitted from other remote units connected in a cascaded manner to remote unit 5, which is directly connected to access unit 1. This optical signal and the signal transmitted from remote unit 5, which is directly connected to access unit 1, are combined and transmitted to access unit 1 via optical switch 51 and optical cable 21.

[0028] The second electro-optical conversion unit 55 converts the optical signal that has come in through the optical cable 21, optical switch 51, and optical multiplexer 53 into an RF signal and supplies it to the amplification unit 60. The RF signal generated by the second electro-optical conversion unit 55 passes through the amplification unit 60, is amplified to an appropriate intensity, and is transmitted to the antenna 59 via the bandpass filter 58. The antenna 59 radiates the RF signal and transmits the signal to the user device. The downlink path is formed in the order of the second electro-optical conversion unit 55, amplification unit 60, bandpass filter 58, and antenna 59, and the uplink path is formed in the reverse order.

[0029] The second photon-wave conversion unit 55 can be connected to multiple amplification units 60. A bandpass filter 58 can be installed between each amplification unit 60 and the antenna 59.

[0030] The second photon converter unit 55 can split and transmit RF signals of different frequency bands to multiple amplification units 60. This frequency band is limited to the range of 4600 to 4800 MHz for type A remote unit 5, and to 4700 to 4900 MHz for type B. The bandpass filter 58 must also be a filter with a passband that matches this band range.

[0031] In the uplink path, RF signals in the aforementioned frequency band are input to the second electro-optical converter 55 via the antenna 59, bandpass filter 58, and amplification unit 60. The second electro-optical converter 55 converts the multiple RF signals input from the multiple amplification units 60 into optical signals, combines them, and transmits them to the access unit 1 via the optical switch 51.

[0032] The remote unit 5 may include a second power supply unit 52 that supplies power to other components.

[0033] The amplification unit 60 adjusts the RF signal generated by the second photon converter unit 55 to an appropriate intensity and outputs it in the downlink path, and adjusts the radio wave signal input through the antenna 59 and bandpass filter 58 to an appropriate intensity and inputs it to the second photon converter unit 55 in the uplink path. As shown in Figure 4, the amplification unit 60 installed in the remote unit 5 may include an uplink amplifier 68, a downlink amplifier 62, a variable attenuator 69, a first switch 61, a second switch 65, a third switch 67, a circulator 63, a variable attenuator 69, and a coupling line 64.

[0034] The amplification unit 60 is equipped with an input terminal 24 for receiving signals from the second photon converter unit 55, and an output terminal 26 for outputting RF signals to the second photon converter unit 55. It also has an input / output terminal 25 for connecting to the antenna 59. During downlink operation, it receives RF signals through the input terminal 24 and outputs signals through the input / output terminal 25. During uplink operation, it receives signals through the input / output terminal 25 and outputs RF signals through the output terminal 26.

[0035] The downlink path connecting input terminal 24 to input / output terminal 25 includes a downlink amplifier 62, a first switch 61, and a circulator 63. The circulator 63 has three terminals: radio waves input to terminal 1 are output to terminal 2, radio waves input to terminal 2 are output to terminal 3, and radio waves input to terminal 3 are output to terminal 1. Terminal 1 is connected to input terminal 24, and terminal 2 is connected to input / output terminal 25. This allows the downlink path to be formed correctly.

[0036] The signal input to the second terminal from the antenna 59 and bandpass filter 58 through the input / output terminal 25 is output through a path connected to the third terminal and output terminal 26. This forms an uplink path. Similar to the downlink path, a second switch 65, an uplink amplifier 68, and a variable attenuator 69 can be installed in the uplink path.

[0037] On the other hand, a third switch 67 can be installed in the uplink path. This switch is connected to a coupling line 64 which is connected to the uplink line. The coupling line 64 is formed to extract the signal from the downlink line and send it back to the second photonic conversion unit 55. The coupling line 64 forms a feedback path.

[0038] One end of the third switch 67 is connected to the output terminal 26, and the other end is connected to the feedback path line and the uplink path line. The third switch 67 is switched so that either the signal from the feedback path or the signal from the uplink path can be selected and output to the output terminal 26.

[0039] In accordance with TDD switching, during downlink operation, the signal input to input terminal 24 passes through the second terminal of circulator 63 and is output to input / output terminal 25. Simultaneously, the downlink signal extracted by coupling line 64 passes through the feedback path and is output from output terminal 26 via third switch 67. This allows the extracted downlink signal to be fed back to second photon converter unit 55. During uplink operation, the signal input to input / output terminal 25 is input to the second terminal of circulator 63, passes through the third terminal, and is output to output terminal 26 via third switch 67 in the uplink path.

[0040] When the downlink signal extracted to the second electro-photoconversion unit 55 is input through the feedback path, the second electro-photoconversion unit 55 analyzes this signal and converts the downlink output signal based on the analysis results. This is to apply digital pre-distortion (DPD) to the downlink output signal. DPD is a technique used to compensate for the nonlinear distortion of high-power amplifiers (HPAs), and it pre-distorts the input signal before transmitting it to the downlink amplifier 62 to compensate for the amplifier's nonlinear characteristics. In this process, distortion in the opposite direction is applied to the input signal so that the signal after passing through the amplifier is as similar as possible to the original linear signal. This reduces nonlinear distortion and improves the quality of the transmitted signal.

[0041] In the TDD downlink section, the first switch 61 closes, and signals are transmitted to the downlink path and the feedback path. At this time, the third switch 67 connects the output terminal 26 to the feedback path. The second switch 65 opens, blocking the transmission of radio waves to the uplink path. Conversely, in the TDD uplink section, the first switch 61 opens, the second switch 65 closes, and the third switch 67 connects the output terminal 26 to the uplink path. The switches are controlled according to the TDD synchronization signal, and the uplink and downlink are switched.

[0042] Theoretically, all signals input to the first terminal of the circulator 63 should be output to the second terminal, and all signals input to the second terminal should be output to the third terminal. However, due to the characteristics of actual analog components, the output is not completely complete, and some radio waves may leak out. In other words, not all signals input to the first terminal are output to the second terminal; some may be output to the third terminal. In this case, if the second switch 65 is ON, the radio waves are transmitted to the uplink amplifier 68, amplified as noise by the uplink amplifier 68, and may spread to other circuits. Therefore, it is necessary to control the first switch 61, the second switch 65, and the third switch 67, rather than relying entirely on the circulator 63. In this way, with a simple configuration including the circulator 63, the first switch 61, the second switch 65, and the third switch 67, the uplink and downlink paths can be completely separated in a time-division transmission structure, and DPD (Digital Pre-distortion) can also be realized.

[0043] The present invention has been described above with reference to one embodiment illustrated in the drawings, but those with ordinary skill in the art will understand that a variety of modifications and equivalent other embodiments are possible. [Explanation of symbols]

[0044] 1: Access Unit 5: Remote Unit 10: Control Unit 13: RF Module 15: First Electronic Light Conversion Unit 19: 1st power supply section 21: Fiber optic cable 51: Optical switch 52: 2nd power supply section 53: Optical Multiplexer 55: Second Electronic Light Conversion Unit 58: Bandpass filter 59: Antenna 60: Amplifier Unit

Claims

1. A distributed antenna system for a 5G-specific network, comprising an access unit and remote units, wherein the access unit uses a frequency band of 4600 to 4900 MHz, and the remote unit is divided into a first type of remote unit supporting a frequency band of 4600 to 4800 MHz and a second type of remote unit supporting a frequency band of 4700 to 4900 MHz, and the system is configured to select and install either the first type of remote unit or the second type of remote unit depending on the location of the building.

2. The distributed antenna system for a 5G specialized network according to claim 1, wherein the access unit includes an RF module and a first electro-optical conversion unit that transmit and receive RF (Radio Frequency) signals with a base station, convert the RF signals into digital signals, and further convert the digital signals into optical signals.

3. The distributed antenna system for a 5G specialized network according to claim 1, wherein the remote unit includes a second electro-optical conversion unit that converts an optical signal received from the access unit into a digital signal and further converts the digital signal into an RF signal, an amplification unit that adjusts the intensity of the RF signal, and a bandpass filter that removes out-of-band noise, and an antenna that radiates radio waves that have passed through the bandpass filter.

4. The distributed antenna system for a 5G specialized network according to claim 3, wherein the remote unit is connected to the access unit and configured to operate only in a specific frequency band in order to minimize interference and provide high-quality service.

5. The distributed antenna system for a 5G specialized network according to claim 3, wherein the remote unit includes an optical switch connected to the access unit by an optical cable, and in the downlink path, an optical signal received in the optical cable is transmitted to another remote unit via the second electro-optical conversion unit and another optical cable, and in the uplink path, an optical signal from another remote unit is transmitted to the access unit via the second electro-optical conversion unit, thereby connecting a plurality of remote units in a cascaded manner.

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