KR20230092080A - In-building Distributed Repeater System - Google Patents

Abstract

An in-building distributed repeater technology that distributes wireless mobile communication signals inside a building is disclosed. In communication between devices in an in-building distributed repeater system, mobile communication signals of service providers are converted into intermediate frequency signals with adjacent frequency bands and transmitted and received as analog signals with compressed bandwidth through frequency division multiplexing. Bandwidth spacings between services of transmitting downstream analog intermediate frequency signals transmitted by a headend unit to a remote service unit are configured to be wider than those of receiving downstream analog intermediate frequency signals received from an active service unit. Accordingly, the price of the system can be reduced.

Description

In-building Distributed Repeater System}

Disclosed is a mobile communication technology, particularly an in-building distributed repeater technology for distributing wireless mobile communication signals inside a building.

[0002] A digital type distribution repeater is known that receives a wireless mobile communication signal transmitted from a mobile communication base station through an antenna and retransmits it to the inside of a building. The distribution repeater demodulates the signal received by the antenna unit, converts it into digital data, and transmits it to the remote service unit, which modulates the signal again and transmits it. As the headend unit and the remote service unit are connected with an Ethernet cable, there is convenience in construction, but as the baseband signal is demodulated, the price increases as the remote service unit installed in large numbers includes a modulation/demodulation circuit.

An object of the proposed invention is to provide a distribution relay system that can be connected with an Ethernet cable while reducing the price by simplifying the configuration of a remote service unit.

Furthermore, the proposed invention aims to propose a new structure of a distribution relay system that can be manufactured using inexpensive parts.

Furthermore, the proposed invention aims to provide a distribution relay system that is easy to construct and economical.

According to one aspect of the proposed invention, mobile communication signals of mobile communication service providers are converted into analog intermediate frequency signals with frequency down and transmitted/received in communication between devices of a distribution relay system within a building.

According to another aspect, the head end unit and the remote service unit may transmit and receive a plurality of analog intermediate frequency signals for each service band through a plurality of signal line pairs of an Ethernet cable.

According to another aspect, the headend unit and the active antenna unit may transmit and receive one analog intermediate frequency signal generated by performing frequency division multiplexing of analog intermediate frequency signals for each service band.

According to another aspect, in the communication between the active antenna unit and the headend unit in the distribution relay system within a building, mobile communication signals of mobile communication service providers are converted into intermediate frequency signals having adjacent frequency bands and compressed through frequency division multiplexing. It can be transmitted and received as an analog signal having a bandwidth.

According to an additional aspect, the inter-band gap of the plurality of analog intermediate frequency signals transmitted from the head end unit to the remote service unit is the same as the inter-band gap of the intermediate frequency signals for each service band of the received downlink analog intermediate frequency signal received from the active antenna unit. It can be configured to be wider than that.

Furthermore, the band gap of intermediate frequency signals for each service band of the transmission upstream analog intermediate frequency signal transmitted from the head end unit to the active antenna unit is wider than the band gap of a plurality of analog intermediate frequency signals received from the remote service unit. It can be configured as a list.

According to an additional aspect, the headend unit may perform frequency division multiplexing of some of the output downlink intermediate frequency signals and transmit the signals through one signal line pair of the Ethernet port.

According to an additional aspect, the remote service unit can receive power from the headend unit through an Ethernet cable without a separate power cable.

Additionally, the active antenna unit can receive power from the headend unit through a communication cable without a separate power cable.

According to a further aspect, the headend unit can manage a plurality of remote service units connected through Ethernet cables through a standard terminal management protocol.

According to the proposed invention, as low-frequency intermediate frequency signals are transmitted and received between the active antenna unit and the headend unit, components of the active antenna unit or headend unit can be used as inexpensive low-frequency ones, thereby reducing the cost of the system. Furthermore, according to the proposed invention, low-frequency intermediate frequency signals are divided for each service band between the remote service unit and the headend unit, divided into a plurality of signal line pairs, and transmitted/received, thereby making parts of the remote service unit or headend unit narrowband It can be used inexpensively, which can lower the cost of the system.

Furthermore, the head-end unit with a built-in digital signal processing circuit can perform high-level signal processing, and the active antenna unit, especially the remote service unit, which occupies a large number in the system, can be implemented simply with analog circuits, thereby lowering the cost of the system. can The head-end unit with a built-in digital signal processing circuit processes the gap between the service bands of the multiplexed intermediate frequency signals to be transmitted to be wider than that of the received one. It is easy to perform analog filtering of one signal, thereby reducing the burden on the specifications of the receiving circuit and enabling implementation at a lower cost.

1 shows the configuration of a distribution repeater system in a building according to an embodiment.
2 is a block diagram showing the configuration of a headend unit according to an embodiment.
3 is a table summarizing frequency bands for each mobile communication service provider in North America.
4 shows examples of analog signals compressed through frequency division multiplexing.
FIG. 5 is a block diagram showing the configuration of an embodiment of a downlink digital repeater in the embodiment of FIG. 2 .
FIG. 6 is a block diagram showing the configuration of an embodiment of an uplink digital relay unit in the embodiment of FIG. 2 .

The foregoing and additional aspects are embodied through embodiments described with reference to the accompanying drawings. It is understood that the components of each embodiment are possible in various combinations within an embodiment unless otherwise stated or contradictory to each other. Each block in the block diagram may represent a physical component in some cases, but in another case, it may be a logical representation of a function of one physical component or a function spanning multiple physical components. Sometimes the object of a block or part thereof may be a set of program instructions. All or part of these blocks may be implemented by hardware, software, or a combination thereof.

<Description of the invention in Fig. 1>

1 shows the configuration of an in-building distribution relay system according to an embodiment. As shown, the in-building distribution relay system includes an antenna 11, an active antenna unit 13, a head end unit 30, and a plurality of remote service units 51, 53, and 55. An antenna 11 is fastened to one side of the active antenna unit. For example, the active antenna unit may be fixed to a wall surface by means of an anchor, or may be installed to a pole through a bracket. The headend unit 30 is manufactured in the form of an enclosure in which a heat dissipation fan is formed outside, and is installed inside a protection cabinet when installed outdoors. A plurality of remote service units 51, 53, and 55 are installed in a space where subscribers using mobile communication terminals are active. Remote service units 51 , 54 , and 56 may be additionally connected to the head end unit 30 through the hub unit 70 .

In the illustrated embodiment, the active antenna unit 13 and the headend unit 30 are connected by a coaxial cable. Also, the plurality of service units 51 , 53 , and 55 and the head end unit 30 may be connected with an Ethernet cable, for example, a CAT6a cable. The hub unit 70 and the head end unit 30 may be connected with an optical cable.

For example, the antenna 11 and the active antenna unit 13 may be installed on a roof of a building, and the headend unit 30 may be installed in a basement. A plurality of remote service units 51, 53, and 55 may be installed in each floor and each room of the underground space. As another example, the antenna 11, the active antenna unit 13, and the headend unit 30 may all be installed on the roof of a building. A plurality of remote service units 51, 53, and 55 may be installed in each floor and each room in the building.

The active antenna unit 13 transmits and receives a wireless mobile communication signal transmitted from the mobile communication base station through the antenna 11. Since different carriers use different bands through different systems, the active antenna unit 13 transmits and receives wireless mobile communication signals of a plurality of bands of a plurality of carriers.

According to one aspect, the active antenna unit 13 performs intermediate frequency demodulation and multiplexing of the radio signal received from the antenna 11 for each service band of the service provider, and transmits the multiplexed signal to the headend unit 30 . The active antenna unit 13 filters and conditions signals for each service band for each band, multiplexes them, amplifies them, and transmits the signals. Accordingly, the active antenna unit 13 and the head end unit 30 can use low-cost thin coaxial cables that have attenuation but are convenient to install instead of 1/2 inch coaxial cables that are generally used in repeaters and are inconvenient to install.

The head end unit 30 converts analog intermediate frequency signals transmitted and received between the active antenna unit 13 and the plurality of remote service units 51, 53, and 55 into digital ones, processes the digital signals, and relays the signals. In the illustrated embodiment, the headend unit 30 has an additional active antenna unit 14 connected thereto. For example, the active antenna unit 13 may be installed on the right side of a building roof facing the base station on the right side, and the active antenna unit 14 may be installed on the left side of the building roof facing the base station on the left side. The head end unit 30 internally checks the quality of radio signals received from the two active antenna units 13 and 14 for each carrier, and selects and relays a good signal among them.

Each of the remote service units 51, 53, and 55 modulates the analog intermediate frequency signal received from the head end unit 30, converts it into a wireless mobile communication signal that can be received by mobile communication terminals, and transmits the signal through an antenna. , Intermediate frequency demodulation of the wireless mobile communication signal received from the antenna is transmitted to the headend unit 30 in the form of an analog intermediate frequency.

Meanwhile, one or a plurality of small cell units 15 may be additionally connected to the headend unit 30 . Service providers can install small cells when base stations of service providers are not nearby or service quality is poor. The head end unit 30 may add the small cell unit 14 to support such changes in operating conditions or environmental limitations. The head end unit 30 internally checks the wireless signals for each carrier received from the two active antenna units 13 and 14 and the quality of the service supported by the small cell unit 14, and among them, the good signal You can relay by selecting .

<Description of Claim 1 Invention>

2 is a block diagram showing the configuration of a headend unit according to an embodiment. The headend unit according to an embodiment includes a downlink digital relay unit 100, an adder 500, and an uplink digital relay unit 300. The headend unit includes a plurality of Ethernet ports 710 and 730 to connect with a plurality of remote service units. Although only two Ethernet ports are shown for convenience of illustration, the actual designed embodiment includes eight ports. Although it is named Ethernet port here, the analog signal transmitted and received does not have to be in the form of an Ethernet packet, but the Ethernet port and cable are physically used, and the present invention is not limited thereto.

The downlink digital relay unit 100 transmits at least one transmitted downlink analog intermediate frequency signal generated by digital signal processing for each service band to the received downstream analog signal input from the active antenna unit to the remote service units. distribute According to one aspect, the headend unit and the plurality of remote service units may transmit and receive signals in a full-duplex manner through one pair of signal lines of an Ethernet cable. In one embodiment, the active antenna unit and the headend unit are connected by a coaxial cable. The headend unit and the plurality of remote service units are each connected with Cat6a UTP cables. Cat6a cable includes 4 pair 8 wire signal lines. In one embodiment, the head end unit and the plurality of remote service units transmit and receive analog intermediate frequency signals through 3 signal line pairs among the 4 pairs of 8 signal lines. In the illustrated embodiment, the head end unit transmits and receives analog intermediate frequency signals through signal line pairs No. 1, 2, and 3 of the CAT6a cable.

The downlink digital repeater 100 samples the received downlink analog intermediate frequency signal received from the active antenna unit through the coaxial cable 210, converts it into a digital signal, processes the digital signal for each service band, and generates the transmitted downlink analog intermediate frequency signal. It is distributed to remote service units through a plurality of Ethernet ports 710 and 730. In one embodiment, digital signal processing is implemented with a field programmable gate array (FPGA), and improves signal relay quality through digital filtering and an interference cancellation system (ICS). Some or all of the signals for each band processed for each service band may be frequency division multiplexed and then converted into an analog signal and distributed through one signal line pair of each of a plurality of Ethernet ports. As another example, signals for each band processed for each service band may be converted into analog intermediate frequency signals and distributed through different signal line pairs of each of a plurality of Ethernet ports. In any case, the same transmitted downlink analog intermediate frequency signal is transmitted to all remote service units through one or more pairs of signal lines.

An adder 500 adds upstream analog intermediate frequency signals received from a plurality of remote service units. Unlike the transmission signal, the signals transmitted by the remote service units, that is, the received upstream analog intermediate frequency signals received by the head end unit, are different for each remote service unit. In one embodiment, the analog intermediate frequency signals transmitted by the remote service units may be signals in which intermediate frequency signals of a plurality of service bands are frequency division multiplexed. As another example, remote service units may transmit analog intermediate frequency signals for each service band by dividing them into a plurality of signal line pairs of an Ethernet cable.

In the illustrated embodiment, the adder 500 transmits the analog intermediate frequency signal received through the first signal line pair of the CAT6a cable of the Ethernet port 710 and the first signal line pair of the CAT6a cable of the Ethernet port 730. The received analog intermediate frequency signal is added. In addition, the adder 500 receives the analog intermediate frequency signal received through the second signal line pair of the CAT6a cable of the Ethernet port 710 and the analog intermediate frequency signal received through the second signal line pair of the CAT6a cable of the Ethernet port 730 add up In addition, the adder 500 is an analog intermediate frequency signal received through the third signal line pair of the CAT6a cable of the Ethernet port 710 and the analog intermediate frequency signal received through the third signal line pair of the CAT6a cable of the Ethernet port 730 add up As is known in the distribution repeater field, mobile communication signals received at each remote service unit can be differentiated at the base station even if they are added together by simple addition.

The uplink digital repeater 300 outputs one transmitted uplink analog intermediate frequency signal generated by digital signal processing for each service band to the active antenna unit.

3 is a table summarizing frequency bands for each mobile communication service provider in North America. The proposed invention will be described by taking the service for the three bands shown in FIG. 3 as an example. Here, the service bandwidth (BW) of the 800 MHz band operator is 32 MHz, the service bandwidth of the 1.9G band operator is 65 MHz, and the service bandwidth of the 2.1G band operator is 70 MHz. The service bands (RF FREQ) of these operators are all sufficiently spaced apart. According to one aspect of the proposed invention, mobile communication signals of service providers are converted into intermediate frequency signals having adjacent frequency bands in communication between devices of an in-building distribution relay system and converted into analog signals having a bandwidth compressed through frequency division multiplexing. can be transmitted and received.

4 shows examples of analog signals converted into intermediate frequency signals having adjacent frequency bands and compressed through frequency division multiplexing. For example, in FIG. 3, the 800M band and the 1.9G band are actually signals separated by a frequency difference of more than two times, but in the proposed invention, when the active antenna unit transmits to the headend unit, the frequency axis as shown in (b) of FIG. It can be frequency-shifted so that it is arranged adjacently in . Meanwhile, the frequency division multiplexed intermediate frequency signals may use signals of a lower frequency band, for example, a 100 MHz band than original mobile communication signals for each service provider. In FIG. 3, IF FREQ@AAU illustrates the frequency (MHz) for each service band of analog intermediate frequency signals transmitted and received between the head end unit and the active antenna unit. In addition, IF FREQ@SU exemplifies the frequency (MHz) for each service band of analog intermediate frequency signals transmitted and received between the head end unit and the remote service unit. Analog intermediate frequency signals that the head end unit transmits and receives through the active antenna unit and the coaxial cable have a bandwidth of less than 600 MHz. Analog intermediate frequency signals that the head end unit transmits and receives to and from the remote service unit are signals in the range of 0-200 MHz for each service band.

For example, in (b) of FIG. 4, 100-132 MHz may be used as the intermediate frequency signal band of the 800 MHz band. Accordingly, devices of an in-building distribution relay system according to an aspect of the proposed invention can transmit and receive wireless communication signals of multiple operators through a cable having a very limited bandwidth such as a coaxial cable or a UTP cable in particular.

That is, the active antenna receives the wireless mobile communication signals transmitted by the base station of each service provider from the antenna, modulates the demodulated baseband signals for each service provider, and shifts the frequency to the frequency band shown in (a) of FIG. shift) to generate intermediate frequency signals for each service provider, add them up, perform frequency division multiplexing for each service band, and transmit them to the headend unit. Similarly, each remote service unit modulates the demodulated baseband signals for each service provider by receiving the wireless mobile communication signals received from the mobile communication terminals from the antenna and shifting the frequency to the frequency band shown in FIG. 4(a) ( frequency shift) to generate intermediate frequency signals for each service provider, add them up, perform frequency division multiplexing for each service band, and transmit them to the headend unit.

<Description of Claim 2 Invention>

According to the applicant's experiments, the amount of signal transmission attenuation of Cat6a cable increases rapidly as the bandwidth exceeds 200 MHz. Accordingly, as shown in FIG. 4(a), a signal having a bandwidth of 287 MHz is unsuitable for transmission and reception between the head end unit and the remote service unit through a single signal wire pair of Cat6a cable.

According to an additional aspect, the headend unit distributes the transmission downlink analog intermediate frequency signal to the remote service units, and divides and distributes the plurality of analog intermediate frequency signals processed for each service band through respective signal line pairs of the Ethernet cable. . In the downlink analog intermediate frequency signal shown in FIG. 4 (a), the divided downlink analog intermediate frequency signal of the 72 MHz band of the 800 MHz service provider is connected to the first signal line pair of the Ethernet port 710 and the Ethernet port 710 as shown in FIG. It is distributed to the No. 1 signal line pair of the port 730. In addition, the divided transmission downlink analog intermediate frequency signal of the 105 MHz band of the 1.9 GHz service provider is distributed to the second signal line pair of the Ethernet port 710 and the second signal line pair of the Ethernet port 730. In addition, the divided transmission downlink analog intermediate frequency signal of the 110 MHz band of the 2.1 GHz service provider is distributed to the third signal line pair of the Ethernet port 710 and the third signal line pair of the Ethernet port 730.

<Description of Claim 3 Invention>

According to an additional aspect, the inter-band gap of the plurality of analog intermediate frequency signals transmitted from the head end unit to the remote service unit is the same as the inter-band gap of the intermediate frequency signals for each service band of the received downlink analog intermediate frequency signal received from the active antenna unit. It can be configured to be wider than that. 4(a) shows an example of frequency band arrangement of a plurality of analog intermediate frequency signals transmitted from the head end unit to the remote service unit. Compared to the received downlink analog intermediate frequency signal received by the head end unit from the active antenna unit shown in FIG. 4(b), the gap between service bands is much wider. For example, the actual data bandwidth of the 800 MHz service band is 32 MHz, the same as that of FIG. 4(b), but an inter-band gap of 20 MHz is added to both sides. Accordingly, it is possible to reduce the burden of circuit specifications for processing the received signal of the remote service unit using the analog band pass filter.

<Description of Claim 4 Invention>

According to a further aspect, the headend unit adds a plurality of received upstream analog intermediate frequency signals received from remote service units, and divides them for each service band through a plurality of signal line pairs of each Ethernet cable. Frequency signals may be added and output for each signal line pair. The uplink digital repeater may frequency division multiplex the analog IF signals for each service band output by the adder to generate and output one transmission uplink analog IF signal.

In the embodiment shown in FIG. 2, the adder 500 is an analog intermediate frequency signal of the 800 MHz band received through the first signal line pair of the Ethernet port 710 and the 800 MHz band received through the first signal line pair of the Ethernet port 730. The analog intermediate frequency signal of is added and output, and the analog intermediate frequency signal of the 1.9 GHz band received through the second signal line pair of the Ethernet port 710 and the 1.9 GHz band received through the second signal line pair of the Ethernet port 730 The analog intermediate frequency signal is added and output, and the analog intermediate frequency signal of the 2.1 GHz band received through the third signal line pair of the Ethernet port 710 and the 2.1 GHz band analog received through the third signal line pair of the Ethernet port 730 The intermediate frequency signal is added and output. The uplink digital repeater 300 frequency-division-multiplexes the analog IF signals for each service band output from the adder to generate one transmit uplink analog IF signal and outputs it through the coaxial cable 210.

<Description of Claim 5 Invention>

According to a further aspect, the inter-band gap of frequency division multiplexed intermediate frequency signals for each service band of the transmitted upstream analog intermediate frequency signal transmitted from the headend unit to the active antenna unit is equal to that of the received upstream analog intermediate frequency signal received from the remote service unit. It may be configured to be wider than the inter-band gap of a plurality of analog intermediate frequency signals of different service bands. 4(a) may be an example of a frequency domain arrangement of a transmitted uplink analog intermediate frequency signal transmitted from the head end unit to the active antenna unit. Similarly, FIG. 4(b) may be an example of frequency domain arrangement of the received upstream analog intermediate frequency signal received by the head end unit from the remote service units. Here, the transmission upstream analog intermediate frequency signal transmitted by the head end unit to the active antenna unit has a much wider gap between service bands than the reception upstream analog intermediate frequency signal received by the head end unit from the remote service unit.

The size of the gap between service bands may be set differently for each service provider band and for a received upstream analog intermediate frequency signal and a transmitted upstream analog intermediate frequency signal. Accordingly, it is possible to reduce the burden of circuit specifications for processing the received signal of the active antenna unit using the analog band pass filter. The coaxial cable has a wider transmission bandwidth than that of the Cat6a Ethernet cable, so that, for example, signals in the 287 MHz band shown in FIG. 4 (a) can be transmitted and received through one cable.

<Description of Claim 6 Invention>

According to an additional aspect, the remote service unit can receive power from the headend unit through an Ethernet cable without a separate power cable. Again in FIG. 2 , the headend unit may further include a remote power transmitter 810 . The IEEE 802.3a standard is known as Power over Ethernet (PoE) and is a technology for transmitting both data and power through a standard Category 5 UTP cable (Cat5 cable). A Power Sending Entity (PSE) checks the specifications of a Powered Device (PD) and transmits appropriate power. One PSE module includes a power transmission circuit to which a standard is applied, and may be configured to transmit suitable power to a plurality of Ethernet terminals through a plurality of ports. A functional block marked as PSE 810 in the drawing may be implemented as a single PSE module having two outputs connected to respective Ethernet ports. In the illustrated example, the remote power transmission unit 810 transmits power through signal line pairs No. 1 through which transmission downlink analog intermediate frequency signals are transmitted.

<Description of Claim 7 Invention>

Additionally, the active antenna unit can receive power from the headend unit through a coaxial cable without a separate power cable. 2, the headend unit may further include an antenna power transmitter 850. PoC (Power over Coaxial) technology is a technology that transmits power by superimposing an analog signal through a coaxial cable, and several technologies are known for each company. The antenna power transmission unit 850 transmits power through an external conductor of a coaxial cable through which transmission uplink analog intermediate frequency signals are transmitted.

<Description of the invention of claim 8>

According to a further aspect, the headend unit can manage a plurality of remote service units connected via Ethernet cables through a standard terminal management protocol, for example Simple Network Management Protocol (SNMP). In the proposed invention, the remote service units and the head end unit transmit and receive analog intermediate frequency signals unrelated to Ethernet. In the embodiment shown in FIG. 2, the headend unit includes a remote unit management unit 830. The remote unit management unit 830 may communicate with each remote service unit through the number 4 signal line pair of the Ethernet ports 710 and 730 . In the illustrated embodiment, the remote unit manager 830 communicates with the remote service unit using a frequency-shift keying (FSK) modem. Through this, the remote unit management unit 830 can update the firmware of the remote service unit or monitor its status.

Additionally, the headend unit can manage one or a plurality of active antenna units connected via coaxial cables through a standard terminal management protocol, for example Simple Network Management Protocol (SNMP). In the embodiment shown in FIG. 2, the headend unit includes an antenna unit management unit 870. The antenna unit management unit 870 may communicate with the active antenna unit through a coaxial cable. In the illustrated embodiment, the antenna unit management unit 870 communicates with the active antenna unit using a frequency-shift keying (FSK) modem. Through this, the antenna unit management unit 870 can update the firmware of the active antenna unit or monitor its status.

<Description of the invention of claim 9>

FIG. 5 is a block diagram showing the configuration of an embodiment of a downlink digital repeater in the embodiment of FIG. 2 . A downlink digital repeater according to an embodiment will be described with reference to FIGS. 1, 2, and 5. As shown, the downlink digital relay unit 100 according to an embodiment includes an analog-to-digital conversion unit 110, a plurality of downlink digital bandpass filters 130-1 to 130-4, and a plurality of downlink intermediate It includes frequency shifting units 150-1 to 150-4 and a signal distribution unit 190. The analog-to-digital conversion unit 110 samples an analog reception downlink analog intermediate frequency signal received through the coaxial connector and converts it into a digital downlink signal. The sampling frequency may be determined according to the bandwidth of the received downlink analog intermediate frequency signal transmitted by the active antenna unit.

Each of the downlink digital bandpass filters 130-1 to 130-4 has filtering characteristics determined according to the service bandwidth of each operator of the received downlink analog intermediate frequency signal transmitted by the active antenna unit. For example, the downlink digital bandpass filter 130-4 may have a bandpass characteristic of passing only signals in the range of 150-220MHz, which is the downlink intermediate frequency signal in the 2.1GHz band in FIG. 3 . In addition, the downlink digital bandpass filter 130-3 may have a bandpass characteristic of passing only signals in the range of 230-300MHz, which is the downlink intermediate frequency signal in the 1.9GHz band in FIG.

Each of the downlink intermediate frequency shifting units 150-1 to 150-4 frequency-shifts the digital downlink signals for each service band output from the corresponding downlink digital bandpass filter into signals within the transmission frequency range of the Ethernet cable, and converts the digital downlink signals into signals within the transmission frequency range of the Ethernet cable. Outputs an intermediate frequency signal. For example, the downlink intermediate frequency shift unit 150-4 frequency shifts the input signal in the range of 150-220 MHz to a signal in the range of 100-170 MHz, which is the transmission downlink intermediate frequency signal range of the 2.1 GHz band in FIG. let it In addition, the downlink intermediate frequency shifting unit 150-3 frequency shifts the input signal in the range of 230-300MHz to a signal in the range of 95-160MHz, which is the range of the transmission downlink intermediate frequency signal in the 1.9GHz band in FIG. 3.

The signal distribution unit 190 converts the digital downlink intermediate frequency signals output from each of the plurality of downlink intermediate frequency modulators 150-1 to 150-4 into analog signals and distributes them to Ethernet ports.

According to an additional aspect, the headend unit may perform frequency division multiplexing of some of the output downlink intermediate frequency signals and transmit the signals through one signal line pair of the Ethernet port. In one embodiment, the signal distribution unit 190 includes a frequency division multiplexing unit 191. The frequency division multiplexing unit 191 frequency division multiplexes the two digital downlink intermediate frequency signals output from the downlink intermediate frequency shifting units 150-1 and 150-2. The digital-to-analog conversion unit 193-1 converts the multiplexed digital downlink intermediate frequency signal output from the frequency division multiplexing unit 191 into an analog signal and converts the first signal line pair (# 1) is distributed as Meanwhile, the digital-to-analog converter 193-3 converts the digital downlink intermediate frequency signal output from the downlink intermediate frequency shifter 150-3 into an analog signal, and converts the second signal line of each of the Ethernet ports 710 and 730. Distribute in pairs (#2). In addition, the digital-to-analog converter 193-4 converts the digital downlink intermediate frequency signal output from the downlink intermediate frequency shifter 150-4 into an analog signal, and converts the third signal line pair of each Ethernet port 710, 730. Divide by (#3).

<Description of Claim 10 Invention>

FIG. 6 is a block diagram showing the configuration of an embodiment of an uplink digital relay unit in the embodiment of FIG. 2 . An uplink digital relay unit according to an embodiment will be described with reference to FIGS. 1, 2 and 6. As shown, the uplink digital relay unit according to an embodiment includes an analog-to-digital converter 390, a plurality of uplink digital bandpass filters 330-1 to 330-4, and a plurality of uplink intermediate frequency transition units ( 350-1 to 350-4), a multiplexing unit 320 and a digital-to-analog conversion unit 310.

The analog-to-digital conversion unit 390 converts the received upstream analog intermediate frequency signal output from the adder 500 into a digital upstream signal. The sampling frequency may be determined according to the bandwidth of the received upstream analog intermediate frequency signal transmitted by the remote service unit.

The plurality of uplink digital bandpass filters 330-1 to 330-4 filter the digital uplink signal for each service band. Each uplink digital bandpass filter has filtering characteristics determined according to the service bandwidth of each operator of the received upstream analog intermediate frequency signal transmitted by the remote service unit. For example, the uplink digital bandpass filter 330-4 may have a bandpass characteristic of passing only signals in the range of 10-80MHz, which is the uplink intermediate frequency signal of the 2.1GHz band in FIG. 3 . In addition, the uplink digital bandpass filter 330-3 may have a bandpass characteristic of passing only a signal in the range of 10-75MHz, which is an upstream intermediate frequency signal in the 1.9GHz band in FIG.

Each upstream intermediate frequency shifting unit outputs a digital upstream intermediate frequency signal by frequency-shifting the digital upstream signals for each service band output from the corresponding upstream digital bandpass filter into signals within the transmission frequency range of the coaxial cable. For example, the uplink intermediate frequency shift unit 350-4 frequency shifts the input signal in the range of 10-80 MHz to a signal in the range of 430-500 MHz, which is the range of the transmission uplink intermediate frequency signal in the 2.1 GHz band in FIG. let it In addition, the upstream intermediate frequency shifting unit 350-3 frequency-shifts the input signal in the range of 10-75 MHz to a signal in the range of 230-300 MHz, which is the range of the transmission upstream intermediate frequency signal in the 1.9 GHz band shown in FIG.

The multiplexer 320 frequency division multiplexes the digital upstream intermediate frequency signals for each service band and outputs a single digital upstream intermediate frequency signal. Since the plurality of uplink intermediate frequency transition units 350-1 to 350-4 have already shifted to an appropriate frequency band, the multiplexer 320 can multiplex the input signals by simply adding them.

The digital-to-analog conversion unit 310 converts the frequency division multiplexed digital uplink intermediate frequency signal into an analog signal and outputs it through a coaxial cable.

<Description of Claim 12 Invention>

According to an additional aspect, the adder 500 may add the analog intermediate frequency signals input by dividing the signal line pairs of the EtherCAT cable for each service band and output the sum for each service band. Two service bands whose frequency bands do not overlap and whose bandwidth is not wide, for example, a 700 MHz band and an 800 MHz band, are frequency division multiplexed so that they can be transmitted and received between the remote service unit and the headend unit. In the embodiment shown in FIG. 6 , the adder 500 includes a first adder 510 , a second adder 530 and a third adder 550 . The first adder 510 is input from the analog intermediate frequency signal input from the first signal line pair (#1) of the first Ethernet port 710 and the first signal line pair (#1) of the second Ethernet port 730 The analog intermediate frequency signal is added and output. The second adder 530 is input from the analog intermediate frequency signal input from the second signal line pair (#2) of the first Ethernet port 710 and the second signal line pair (#2) of the second Ethernet port 730 The analog intermediate frequency signal is added and output. The third adder 550 is input from the analog intermediate frequency signal input from the third signal line pair (#3) of the first Ethernet port 710 and the third signal line pair (#3) of the second Ethernet port 730 The analog intermediate frequency signal is added and output.

In FIG. 6, the first analog-to-digital converter 393-1 converts the output of the first adder 510 into a digital upstream signal. In addition, the second analog-to-digital converter 393-2 converts the output of the second adder 530 into a digital upstream signal, and the third analog-to-digital converter 393-3 converts the output of the third adder 550 Converts the output into a digital up signal.

In the illustrated embodiment, the output of the first analog-to-digital converter 393-1 may be commonly supplied to the first digital band-pass filter 330-1 and the second digital band-pass filter 330-2. there is. The first digital bandpass filter 330-1 filters the output of the first analog-to-digital converter into a first service band. The second digital bandpass filter 330-2 filters the output of the first analog-to-digital converter into a second service band.

In the above, the present invention has been described through embodiments with reference to the accompanying drawings, but is not limited thereto, and should be interpreted to cover various modifications that can be obviously derived by those skilled in the art. The claims are intended to cover these variations.

11: antenna 13: active antenna unit
15: small cell unit 30: head end unit
51, 52, 53, 54, 55, 56: remote service unit
70: hub unit
100: downlink digital relay unit
110: analog-to-digital converter 130: downlink digital band pass filter
150: downlink intermediate frequency transition unit 190: signal distribution unit
210: coaxial cable
300: upstream digital relay unit
500: adder
710, 730: Ethernet port
711-714, 731-734: pair of signal lines
810,: remote power transmission unit 830: remote unit management unit
850: antenna power transmission unit 870: antenna unit management unit

Claims (20)

In the headend unit of a mobile communication relay system connected to an active antenna unit on one side and connected to a plurality of remote service units and an Ethernet cable on the other side,
A downstream digital repeater that distributes the transmit downlink IF signal generated by digital signal processing for each service band to the received downstream analog IF signal input from the active antenna unit to the remote service units. repeat unit) and;
an adder for adding upstream analog intermediate frequency signals received from a plurality of remote service units;
an upstream digital repeat unit that outputs one transmitted upstream analog intermediate frequency signal generated by processing the output of the adder into a digital signal for each service band to the active antenna unit;
Headend unit including a. The headend of claim 1, wherein the downlink digital repeater distributes the transmitted downlink analog intermediate frequency signals to the remote service units, and divides and distributes the plurality of analog intermediate frequency signals processed for each service band through respective signal line pairs of the Ethernet cable. unit. The method of claim 2,
The headend unit configured to widen the bandgap spacing of the plurality of analog intermediate frequency signals more than the bandgap spacing of the intermediate frequency signals for each service band of the received downlink analog intermediate frequency signal. The method of claim 2,
The adder adds the received uplink analog intermediate frequency signals, and adds up and outputs a plurality of analog intermediate frequency signals received by dividing them for each service band through a plurality of signal line pairs of each Ethernet cable for each signal line pair,
The uplink digital repeater is a headend unit that frequency division multiplexes analog IF signals for each service band output from the adder to generate one transmission uplink analog IF signal. The method according to claim 4, wherein the uplink digital repeater receives the interband gap of the intermediate frequency signals for each frequency division multiplexed service band of the transmitted upstream analog intermediate frequency signal and receives a band of a plurality of analog intermediate frequency signals of different service bands of the uplink analog intermediate frequency signal A headend unit configured to be wider than the inter-gap. The method of claim 1 , wherein the headend unit:
The headend unit further comprising a remote power sending unit for transmitting power to a remote service unit through the Ethernet cable. The method of claim 1 , wherein the headend unit:
A headend unit further comprising a power sending unit connected to the active antenna unit through a coaxial cable and transmitting power to the active antenna unit through the coaxial cable. The method of claim 1 , wherein the headend unit:
a remote unit management unit communicating with a plurality of remote service units connected through the Ethernet cables to perform a management function of the remote service units;
Headend unit further comprising a. The method according to claim 1, the downlink digital relay unit:
an analog-to-digital converter for receiving a downlink analog intermediate frequency signal in which a plurality of intermediate frequency signals of different service bands are frequency division multiplexed from the active antenna unit and converting the received downlink analog intermediate frequency signal into a digital downlink signal;
a plurality of downlink digital bandpass filters for outputting digital downlink signals for each of a plurality of service bands by filtering digital downlink signals for each service band;
a plurality of downlink intermediate frequency shifting units for frequency shifting digital downlink signals for each service band into signals within a transmission frequency range of the Ethernet cable and outputting digital downlink intermediate frequency signals;
A headend unit comprising a signal distribution unit that converts digital downlink intermediate frequency signals outputted from each of the plurality of intermediate frequency modulators into analog signals and distributes them to Ethernet ports. The method according to claim 1, the uplink digital relay:
an analog-to-digital converter for converting the received uplink analog intermediate frequency signal output from the adder into a digital uplink signal;
a plurality of uplink digital bandpass filters for filtering the digital uplink signal for each service band;
a plurality of uplink intermediate frequency transition units for frequency-shifting digital uplink signals for each service band into signals within a transmission frequency range of the coaxial cable and outputting digital uplink intermediate frequency signals;
a multiplexing unit that performs frequency division multiplexing of digital upstream intermediate frequency signals for each service band and outputs a single digital upstream intermediate frequency signal;
a digital-to-analog conversion unit for converting the frequency division multiplexed digital uplink intermediate frequency signal into an analog signal and outputting the converted analog signal to the active antenna unit;
Headend unit including a. The method according to claim 9, the signal distribution unit:
at least one frequency division multiplexing unit for frequency division multiplexing two of the digital downlink intermediate frequency signals output from the downlink intermediate frequency shift unit; a first digital-to-analog converter for distributing signal lines;
a second digital-to-analog conversion unit converting the digital downlink signal for each filtered service band into an analog signal and distributing it to a second signal line pair of each Ethernet port;
Headend unit including a. 10. The method of claim 9, wherein the adder:
a first adder for adding the analog intermediate frequency signal input from the first signal line pair of the first Ethernet port and the analog intermediate frequency signal input from the first signal line pair of the second Ethernet port;
a second adder for adding the received uplink analog intermediate frequency signal input from the second signal line pair of the first Ethernet port and the received uplink analog intermediate frequency signal input from the second signal line pair of the second Ethernet port;
Headend unit including a. The method according to claim 12, the uplink digital relay unit:
a first analog-to-digital conversion unit that converts the output of the first adder into a digital uplink signal;
a second analog-to-digital converter for converting the output of the second adder into a digital uplink signal;
A headend unit comprising a third analog-to-digital conversion unit that converts the output of the third adder into a digital upstream signal. The method according to claim 13, the uplink digital relay unit:
a first digital bandpass filter filtering an output of the first analog-to-digital conversion unit into a first service band;
a second digital bandpass filter filtering the output of the first analog-to-digital conversion unit into a second service band;
Headend unit including a. Analog intermediate frequency signals obtained by frequency-shifting wireless mobile communication signals of a plurality of service bands received from a plurality of mobile communication base stations are amplified and transmitted after frequency division multiplexing, and the received frequency division multiplexed analog intermediate frequency signals are transmitted in the service band. an active antenna unit that transmits a wireless mobile communication signal for each service band to a plurality of mobile communication base stations by performing frequency shift;
Transmitting analog intermediate frequency signals obtained by frequency shifting wireless mobile communication signals of a plurality of service bands received from a mobile communication terminal, and frequency shifting the received analog intermediate frequency signals for each service band to transmit wireless mobile communication signals for each service band a remote service unit;
It is connected to the active antenna unit and connected to the remote service unit through an Ethernet cable. The frequency division multiplexed analog intermediate frequency signal input from the active antenna unit is separated by service band, processed as a digital signal, and distributed to the remote service units. A digital repeater (downstream digital repeat unit), an adder for adding analog intermediate frequency signals received from a plurality of remote service units, and one transmission upstream analog intermediate frequency generated by digital signal processing of the output of the adder for each service band a headend unit including an upstream digital repeat unit outputting a signal to an active antenna unit;
In-building distribution relay system including a. The method according to claim 15, wherein the active antenna unit transmits an analog intermediate frequency signal having a compressed bandwidth through frequency division multiplexing by frequency-shifting the received wireless mobile communication signals of a plurality of service bands into intermediate frequency signals having adjacent frequency bands In-building distribution relay system. The in-building distribution relay system of claim 15, wherein the downlink digital repeater of the headend unit divides and distributes a plurality of analog intermediate frequency signals separated and processed for each service band through respective signal line pairs of Ethernet cables. 16. The method of claim 15, wherein the headend unit:
A distribution relay system in a building that transmits power to a remote service unit through the Ethernet cable. 16. The method of claim 15, wherein the headend unit:
An in-building distribution relay system that is connected to the active antenna unit through a coaxial cable and transmits power to the active antenna unit through the coaxial cable. 16. The method of claim 15, wherein the headend unit:
a remote unit management unit communicating with a plurality of remote service units connected through the Ethernet cables to perform a terminal management function;
In-building distribution relay system further comprising a.

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