KR102847905B1 - A dual band repeater module for a local 5g network - Google Patents

Abstract

A dual-band relay module for a 5G specialized network according to an embodiment of the present invention comprises: a master unit that receives a radio signal in a 4.7 GHz band and a radio signal in a 28 GHz band from a donor antenna and converts them into optical signals; a plurality of remote units that are connected to the master unit via an optical path and receive signals from the master unit via the optical path and transmit and receive radio waves in a service area; wherein the master unit comprises: an antenna for transmitting and receiving a signal transmitted from the donor antenna; a circulator connected to the antenna; a switch connected to a port of the circulator through which the antenna signal is output and arranged in a downlink path; a first amplifier connected to the switch and amplifying a downlink signal; a second amplifier that amplifies an uplink signal and inputs the amplified signal to the circulator, thereby supplying the uplink signal to the antenna via the circulator; The control unit controls the above switch to be turned on and off depending on whether it is an uplink slot or a downlink slot; separates the uplink path and the downlink path, and can activate the uplink path or the downlink path in a time-division manner.

Description

A dual-band repeater module for a local 5G network.

The present invention relates to a dual-band relay module for a 5G specialized network, and more specifically, to a relay module that can relay radio waves without a shadow area in a private network or specialized network using 5G, and transmits uplink signals and downlink signals in a time-division manner in a TDD manner.

A 5G specialized network is a customized network that can implement cutting-edge services desired by demand companies in specific spaces (buildings, facilities, locations, etc.) through dedicated frequencies rather than existing mobile communication commercial networks.

A relay module is being developed to ensure call and data quality in shadow areas that arise during the construction of a 5G service network.

Korean Patent No. 2013336 discloses a distributed antenna system and a remote unit device thereof for transmitting service signals and management control signals in a 5G mobile communication system.

This distributed antenna system connects multiple remote unit devices in a cascade manner to a master unit device by having a remote unit device deployed in a service area distribute an input downward optical signal into first and second downward electrical signals, output the first downward electrical signal to an antenna, transmit the second downward electrical signal to a remote unit device at a subsequent location, and convert the first upward electrical signal received by the antenna and the second upward electrical signal converted from the input upward optical signal into the upward optical signal and outputting the combined signal.

The present invention was created to provide a dual-band relay module for a 5G specialized network that can stably separate the uplink path and downlink path of a TDD network.

A dual-band relay module for a 5G specialized network according to an embodiment of the present invention comprises: a master unit that receives a radio signal in a 4.7 GHz band and a radio signal in a 28 GHz band from a donor antenna and converts them into optical signals; a plurality of remote units that are connected to the master unit via an optical path and receive signals from the master unit via the optical path and transmit and receive radio waves in a service area; wherein the master unit comprises: an antenna for transmitting and receiving a signal transmitted from the donor antenna; a circulator connected to the antenna; a switch connected to a port of the circulator through which the antenna signal is output and arranged in a downlink path; a first amplifier connected to the switch and amplifying a downlink signal; a second amplifier that amplifies an uplink signal and inputs the amplified signal to the circulator, thereby supplying the uplink signal to the antenna via the circulator; The control unit controls the above switch to be turned on and off depending on whether it is an uplink slot or a downlink slot; separates the uplink path and the downlink path, and can activate the uplink path or the downlink path in a time-division manner.

The above remote unit may include a second antenna for transmitting and receiving signals transmitted from devices in a service area; a second circulator connected to the second antenna; a second switch connected to a port of the second circulator through which the second antenna signal is output and arranged in an uplink path; a third amplifier connected to the second switch and amplifying an uplink signal; a fourth amplifier amplifying a downlink signal and inputting the amplified signal to the second circulator, thereby supplying the downlink signal to the second antenna through the second circulator; and a control unit for controlling the second switch to be turned on and off depending on whether it is an uplink slot or a downlink slot.

It may further include a TDD synchronization detection unit that extracts a TDD synchronization detection signal from a signal received by the antenna and transmits it to the control unit.

The above control unit may include a TDD-Sync module that receives a TDD synchronization detection signal and generates a switch control signal; and a switch control unit that controls the switch on and off according to the control signal of the TDD-Sync module.

The above antenna includes a 4.7 GHz antenna and a 28 GHz antenna, which are installed separately, and the 4.7 GHz antenna receives an Hmain signal and a Vmimo signal, respectively, and the 28 GHz antenna receives an Hmain signal and a Vmimo signal, respectively, and a configuration for separating an uplink path and a downlink path, including the circulator, the switch, the first amplifier, and the second amplifier, may be installed in multiple numbers corresponding to the Hmain path of the 4.7 GHz antenna, the Vmimo path of the 4.7 GHz antenna, the Hmain path of the 28 GHz antenna, and the Vmimo path of the 28 GHz antenna, respectively.

According to an embodiment of the present invention, an uplink path and a downlink path can be reliably separated in TDD communication using a simple and stable configuration.

Figures 1 and 2 are block diagrams of the entire dual-band relay module system according to an embodiment of the present invention.
Figure 3 is a block diagram showing the internal configuration of a master unit of a dual-band relay module according to an embodiment of the present invention.
Figures 4 and 5 are block diagrams showing the internal configuration of a remote unit of a dual-band relay module according to an embodiment of the present invention.
Figures 6 and 7 are drawings explaining uplink and downlink path switching of a dual-band relay module according to an embodiment of the present invention.

The technical objectives achieved by the present invention and its implementation will become clearer with the help of the preferred embodiments of the present invention described below. The following examples are provided merely to illustrate the present invention and are not intended to limit the scope of the present invention.

Figures 1 and 2 are block diagrams of the entire dual-band relay module system according to an embodiment of the present invention.

Dual-band relay modules can be used to build specialized 5G networks. These networks are customized networks that enable companies to implement cutting-edge services in specific spaces (buildings, facilities, locations, etc.) using dedicated frequencies, rather than existing mobile telecommunications commercial networks.

While existing 5G mobile communication networks provide services to the entire nation by building large-scale nationwide networks using frequencies allocated to a small number of operators, 5G specialized networks differ from 5G mobile communication networks in that they allow companies or operators to build customized wireless networks to apply 5G services within limited areas such as buildings, facilities, and land.

A dual-band relay module for a 5G specialized network according to an embodiment of the present invention may include a master unit (1) and remote units (2, 3). The remote units (2, 3) may include a remote unit (2) for 4.7 GHz and a remote unit (3) for 28 GHz.

Communications using the 4.7 GHz band are relatively slower than those using the 28 GHz band, but they are more stable and require less installation and maintenance costs. While 28 GHz bands offer ultra-high speeds and ultra-low latency, their relatively narrow radio range means higher installation and maintenance costs.

To ensure adequate 5G performance throughout the entire business site while requiring ultra-high-speed, ultra-low-latency services in select areas (e.g., for high-definition video-based product quality assessment), the 4.7 GHz band can be used as a base for wireless coverage, while the 28 GHz band can be deployed as a hotspot. This approach could involve providing 4.7 GHz 5G service with a certain level of performance while simultaneously offering 28 GHz service in select areas that require higher performance. Of course, providing 4.7 GHz and 28 GHz services to all areas is also feasible.

As illustrated in Figures 1 and 2, the master unit (1) receives a signal from an external donor such as a base station, converts it into an optical signal, and transmits it to a remote unit (2, 3) via an optical path. The remote unit (2, 3) that receives the optical signal converts it back into a radio wave and transmits it to the service area.

An optical signal transmitted from a master unit (1) to a 4.7 GHz remote unit (2) can be transmitted to other 4.7 GHz remote units in a cascade manner. Similarly, an optical signal transmitted to a 28 GHz remote unit (3) can be transmitted to other 28 GHz remote units (3) in a cascade manner.

The master unit (1) accommodates both 4.7 GHz and 28 GHz, but the remote units (2, 3) can independently operate 4.7 GHz and 28 GHz, allowing flexible service operation.

As illustrated in Fig. 2, the master unit (1) may include a 4.7 GHz transceiver (11) and a 28 GHz transceiver (13). A 28 GHz radio wave received by the 28 GHz transceiver (13) may be converted to 5 GHz by a frequency converter (15) and then combined with a 4.7 GHz radio wave by a frequency combiner (17). This combined radio wave may be converted into an optical signal by an optical converter (19), and this optical signal may be transmitted to remote units (2, 3).

An optical path can be connected between a master unit (1) and a 4.7 GHz remote unit (2). The 4.7 GHz remote unit (2) can have an optical distribution unit (21). The optical distribution unit (21) can distribute an optical signal received from the master unit (1) to a 28 GHz remote unit (3).

An optical switch unit (23, 31) may be installed in each of the 4.7 GHz remote unit (2) and the 28 GHz remote unit (3). The optical switch unit (23, 31) may switch so that the remote unit (2, 3) can selectively receive the optical signal transmitted from the master unit (1). In the event of a failure in the remote unit (2, 3), the optical signal is directly transmitted to the next remote unit connected in a cascade manner from the optical switch unit (23, 31), thereby maintaining wireless coverage.

The 4.7 GHz remote unit (2) may have an optical conversion unit (25). The optical conversion unit (25) converts an optical signal received from the master unit (1) into an electrical signal. This radio signal includes both radio waves in the 4.7 GHz band and radio waves in the 5 GHz band. The 4.7 GHz remote unit (2) is equipped with a frequency separator (27) to remove radio waves in the 5 GHz band.

A 4.7 GHz remote unit (2) may be equipped with a 4.7 GHz transceiver (29). By providing signals in the 4.7 GHz band to the final service area, signals transmitted from the master unit (1) can be transmitted to devices in the service area. Conversely, signals transmitted by devices can also be transmitted to the master unit (1) via the uplink path.

The 28GHz remote unit (3) may also be equipped with a light conversion unit (33), a frequency separation unit (35), and a 28GHz transceiver unit (39). In addition, it may include a frequency conversion unit (37). The frequency conversion unit (37) converts 5GHz radio waves into 28GHz band radio waves.

In this way, the master unit (1) of the dual-band relay module receives radio waves in the 4.7 GHz and 28 GHz bands, converts the radio waves in the 28 GHz band into 5 GHz, combines the converted 5 GHz band radio waves and the 4.7 GHz band radio waves, converts them into optical signals, and transmits them to the remote units (2, 3). The 28 GHz remote unit (3) converts radio waves in the 5 GHz band into radio waves in the 28 GHz band and transmits them.

Radio waves in the 28 GHz band are specifically converted into radio waves in the 5 to 5.6 GHz band range, and radio waves in the 4.7 GHz band have a specific band range of 4.72 to 4.82 GHz. Therefore, a guard band of 0.18 GHz can be formed between the two radio bands. If this guard band is too narrow, there is a high possibility that the two signals will interfere with each other. On the other hand, if it is too wide, the hardware used to transmit the signal must be configured with high specifications, which can cause an increase in cost. This is because the wider the guard band, the wider the bandwidth, and the wider the bandwidth, the higher the hardware and software specifications to process it must be configured with. For this reason, radio waves in the 28 GHz band are converted into radio waves in the 5 to 5.6 GHz band range and combined with radio waves in the 4.7 GHz band for transmission.

As illustrated in Fig. 3, the 4.7 GHz transceiver (11) of the master unit (1) receives radio waves through a 4.7 GHz antenna (111). The 4.7 GHz antenna (111) divides the radio waves into two signals, Hmain and Vmimo, and receives them. The radio waves pass through a circulator (112), a switch (113), an amplifier (114), a bandpass filter (117), an attenuator (118), etc., and are then transmitted to a frequency coupling unit (17).

The circulator (112) and switch (113) separate the uplink and downlink paths and transmit radio waves. Since 5G communication is performed in TDD mode, transmission and reception are performed alternately through the uplink and downlink paths at specific times. The downlink path transmits radio waves in the direction from left to right in FIG. 3, and the uplink path transmits radio waves in the direction from right to left in FIG. 3.

The 28GHz transceiver (13) also transmits and receives radio waves through a 28GHz antenna (131). Like the 4.7GHz transceiver (11), it has a configuration including a circulator (139) and a switch (138), and transmits and receives Hmain and Vmimo signals separately.

The master unit (1) has 4.7 GHz and 28 GHz antennas (111, 131) installed independently. Accordingly, the separate antennas can be tilted individually. Even if the 4.7 GHz base station and the 28 GHz base station are located in different locations, the 4.7 GHz antenna (111) can be tilted to face the 4.7 GHz base station (donor antenna), and the 28 GHz antenna (131) can be angle-adjusted to face the 28 GHz base station (donor antenna) independently of the 4.7 GHz antenna (111).

Radio waves in the 28 GHz band are converted into radio waves in the 5 to 5.6 GHz band range in the frequency conversion unit (15). For this purpose, the frequency conversion unit (15) may include an oscillator (152), mixers (153, 154), and a low-pass filter (156). The frequency of radio waves in the 28 GHz band is converted by synthesizing the radio waves generated by the oscillator (152) with the mixers (153, 154). High-frequency noise may be generated during the frequency conversion process, and the low-pass filter (156) removes such noise.

The frequency conversion unit (15) also includes a splitter (159). The splitter (159) divides the radio waves generated by the oscillator (152) into two and supplies them to a mixer (153) of the uplink path and a mixer (154) of the downlink path. Therefore, frequency conversion of the uplink path and the downlink path is possible with a single oscillator (152).

Radio waves of the 4.7 GHz band (specifically, 4.72 to 4.82 GHz) and the 5 GHz band (specifically, 5 to 5.6 GHz) are combined in a frequency combining unit (17). The frequency combining unit (17) includes combiners (171, 172). The combiners (171, 172) may include a first combiner (171) that combines a 4.7 GHz Hmain downlink signal and a 5 GHz (28 GHz before conversion) Hmain downlink signal, and a second combiner (172) that combines a 4.7 GHz Vmimo downlink signal and a 5 GHz (28 GHz before conversion) Vmimo downlink signal.

The optical conversion unit (19) may include an optical-electronic converter (194). The Hmain signals of 4.7 GHz and 5 GHz (28 GHz) and the Vmimo signals of 4.7 GHz and 5 GHz (28 GHz) are each converted into optical signals of different wavelengths by the optical-electronic converter (194). These can be combined in a CWDM manner by a multiplexer (196) and transmitted externally through an optical path (9).

The remote unit (2) for 4.7 GHz illustrated in FIG. 4 receives an optical signal and separates it by wavelength. Accordingly, the Hmain optical signal and the Vmimo optical signal can be separated. In addition, the optical signal is converted into a radio signal by the optical-electronic converter (251). Only the signal in the 4.7 GHz band is extracted from the radio signal by the bandpass filter (271). The signal in the 4.7 GHz band is divided by the distributor (278), and some of the signal can be transmitted through the 4.7 GHz transceiver (29), and some of the signal can be converted into an optical signal again by the optical-electronic converter (281) and combined by the multiplexer (282). As illustrated in FIG. 1, the remote unit (2) for 4.7 GHz can be connected in a cascade manner with multiple remote units (2, 3). This optical signal can be transmitted to another 4.7 GHz remote unit (2) via an optical path. Since the signal is converted from photoelectric to electrical and then converted back to optical before being transmitted to another remote unit, signal reliability is high. Furthermore, signals from multiple remote units can be sequentially synthesized.

As illustrated in Fig. 5, the remote unit (3) for 28 GHz has a similar configuration to the remote unit (2) for 4.7 GHz. That is, the remote unit (3) for 28 GHz may include a photoelectric converter (331), a bandpass filter (351), and a splitter (378). In addition, it may include a beamforming chip (391) and an array antenna (392) to transmit radio waves by beamforming in a MIMO manner. Since radio waves in the 28 GHz band have a high frequency and the radio wave reach distance may be too short, beamforming is performed to increase the radio wave reach distance while allowing radio waves to reach a specific location.

In the above, the components have been described with a focus on the downlink path. In the uplink path, the components are arranged symmetrically to the downlink path. That is, the radio waves transmitted from devices in the service area are received by the 4.7 GHz antenna (291) shown in Fig. 4 and converted into optical signals through the circulator (243), switch (245), combiner (277), and optical-to-electronic converter (259). The Hmain optical signal and the Vmimo optical signal are combined by the multiplexer, and combined with the optical signals transmitted from other remote units (2, 3) in the optical distribution unit (21) and transmitted to the master unit (1). The 28 GHz remote unit (3) also has an uplink path formed in a similar manner as above.

Referring to Fig. 3, an optical signal received by the master unit (1) is converted into an optical signal and distributed by a distributor (177, 178) and supplied to a 4.7 GHz antenna (111) and a 28 GHz antenna (131), respectively. The 4.7 GHz antenna (111) and the 28 GHz antenna (131) transmit signals to the donor antenna.

Accordingly, four paths are formed in the 4.7 GHz transceiver (11) of the master unit (1), including the Hmain uplink path, the Hmain downlink path, the Vmimo uplink path, and the Vmimo downlink path. Similarly, four paths are formed in the 28 GHz transceiver (13), so that a total of eight paths are formed in the master unit (1). By integrating these eight paths into one optical path (9), the master unit (1) and remote units (2, 3) are connected and can transmit and receive signals.

As mentioned above, the 5G network communicates in TDD mode. Therefore, when the downlink path is activated, the uplink path is deactivated, and when the uplink path is activated, the downlink path is deactivated. As illustrated in FIGS. 3 and 4, a circulator (112, 243) and a switch (113, 245) are installed immediately after the antenna (111, 131) of the master unit (1) and immediately after the antenna (291) of the remote unit (2, 3). The uplink path and the downlink path are separated by the circulator (112, 243) and the switch (113, 245), and uplink signal transmission and downlink signal transmission are performed alternately over time.

Accordingly, the switches (113, 245) must be operated according to the determined uplink time slot and downlink time slot. The master unit (1) has a TDD synchronization detection unit (5) as illustrated in Fig. 3. The TDD synchronization detection unit (5) extracts a TDD synchronization detection signal (Synchronization Signal Block) from a signal received from a donor antenna, and accordingly, the switches (113, 245) of the master unit (1) and remote units (2, 3) can be controlled so that an uplink path is connected to the uplink time slot and a downlink path is connected to the downlink time slot. The control unit and the switches (113, 245) and the control unit and the TDD synchronization detection unit (5) are electrically connected, respectively, so that a synchronization detection signal and a control signal can be transmitted through a line.

Figures 6 and 7 illustrate a portion of a 4.7 GHz transceiver (11) including an antenna (111), a circulator (112), and a switch (113) in the master unit (1) of Figure 3. Figure 6 shows the state and signal flow of the switch (113) when the uplink path is activated, and Figure 7 shows the state and signal flow of the switch (113) when the downlink path is activated.

The control unit may include a TDD-sync module (6) that receives a synchronization signal from a TDD synchronization detection unit (5) and a switch control unit (7). According to the control of these, the state of the switch (113) can be switched ON/OFF.

As shown in Fig. 6, in the uplink state, the switch is in the OFF state, i.e., a short-circuit state.

When the uplink path is activated, the amplified radio signal through the second amplifier (115) passes through the circulator (112) and is transmitted to the donor antenna through the antenna (111). The circulator (112) may have three ports (a, b, c).

Port A is connected to the second amplifier (115) by a line, port B is connected to the antenna (111) by a line, and port C is connected to the switch (113) by a line. The circulator (112) outputs a signal input to port A through port B, outputs a radio wave input through port B through port C, and outputs a signal input through port C through port A.

In theory, all signals input to port A should be output to port B, but due to the characteristics of actual analog devices, they are not perfectly output to port B, and some waves may be output to port C. In this case, if the switch (113) is in the ON state, the waves are transmitted to the first amplifier (114), and may be amplified by the first amplifier (114) and become noise that may circulate to other circuits. Therefore, rather than relying entirely on the circulator (112), the switch (113) is also controlled.

As illustrated in Fig. 7, when in a downlink state, the switch (13) is turned on in reverse. That is, the radio waves input to the b port of the circulator (112) through the antenna (111) are output to the c port and are transmitted to the switch (113) connected to the c port. Since the switch (113) is in the ON state, i.e., in a connected state, the radio waves passing through the switch (113) can be transmitted to the first amplifier (114).

Even in the downlink state, current leakage from the circulator (112) may naturally occur. That is, the radio waves input to port b may not be output only to port c, but some may leak to port a. However, the radio waves leaking from port a are connected to the output port of the second amplifier (115), but since the output side of the amplifier has high impedance, the radio waves will not proceed any further and will be dissipated.

In this way, it has a simple configuration including an antenna (111), a circulator (112), and a switch (113) connected to a port through which a signal from the antenna (111) is output, and by controlling only the switch (113), it is possible to separate the uplink and downlink paths in a time division transmission structure.

As illustrated in Fig. 3, a configuration in which an antenna (111) and a circulator (112) are connected, and a port from which a signal of a port connected to the antenna (111) is output is connected to a switch (113), thereby separating uplink and downlink paths, is formed in the master unit (1) with four paths. That is, two paths are formed with Hmain and Vmimo of the 4.7 GHz transceiver (11), and two paths are formed with Hmain and Vmimo of 28 GHz. As illustrated in Fig. 4, a configuration including an antenna (291), a circulator (243), and a switch (245) is formed for each of Hmain and Vmimo in the 4.7 GHz remote unit (2). A configuration like this can also be installed in the 28 GHz remote unit (3).

Although the present invention has been described above with reference to one embodiment shown in the drawings, those skilled in the art will understand that various modifications and equivalent other embodiments are possible.

1: Master unit 2: 4.7GHz remote unit
3: 28GHz remote unit 15: Frequency converter
17: Frequency coupling unit 19: Optical conversion unit
27: Frequency separation unit 111: Antenna
112: Circulator 113: Switch

Claims (5)

A master unit that receives radio signals in the 4.7 GHz band and radio signals in the 28 GHz band from a donor antenna and converts them into optical signals;
It includes a plurality of remote units that are connected to the master unit through an optical path and receive signals from the master unit through the optical path and transmit and receive radio waves to the service area;
The above master unit is,
An antenna for transmitting and receiving signals transmitted from a donor antenna;
A circulator connected to the above antenna;
A switch connected to a port of the circulator from which the antenna signal is output and placed in a downlink path;
A first amplifier connected to the above switch and amplifying a downlink signal;
A second amplifier that amplifies an uplink signal and inputs it to the circulator, thereby supplying the uplink signal to the antenna through the circulator;
Separating the uplink path and the downlink path, including a control unit that controls the above switch to be turned on and off depending on whether it is an uplink slot or a downlink slot;
Activates uplink path or downlink path in time division manner,
The above remote unit is,
A second antenna for transmitting and receiving signals transmitted from devices in the service area;
A second circulator connected to the second antenna;
A second switch connected to a port of the second circulator from which the second antenna signal is output and placed on an uplink path;
A third amplifier connected to the second switch and amplifying the uplink signal;
A fourth amplifier that amplifies a downlink signal and inputs it to the second circulator, thereby supplying the downlink signal to the second antenna through the second circulator;
It includes a control unit that controls the second switch to be turned on and off depending on whether it is an uplink slot or a downlink slot;
It further includes a TDD synchronization detection unit that extracts a TDD synchronization detection signal from a signal received by the antenna and transmits it to the control unit;
The above control unit,
TDD-Sync module that receives TDD synchronization detection signal and generates switch control signal;
A dual-band relay module for a 5G specialized network, comprising a switch control unit that controls the switch on and off according to a control signal of the TDD-Sync module.
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