KR101909283B1 - Combiner and multi-band base station system using the combiner - Google Patents

Abstract

A multi-band base station system including a combiner and such a combiner is disclosed. The combiner according to the present invention is a combiner that is installed between a plurality of base stations and a plurality of antennas of a multi-band base station system to enable antenna beam tilt control, and is a filter unit for separating or merging RF signals of a plurality of frequency bands ; And a modem for modulating a digital control signal for antenna beam tilt control into an RF control signal or demodulating an RF control signal for antenna beam tilt control into a digital control signal.

Description

COMBINER AND MULTI-BAND BASE STATION SYSTEM USING THE COMBINER USING THE SAME

The present invention relates to a multi-band base station system, and more particularly to a combiner applied to a multi-band base station system and a multi-band base station system using such a combiner.

In the current mobile communication environment, the next generation 4G LTE (Long Term Evolution) system is being introduced as well as commercialization of 2G (Generation) and 3G, and a variety of mobile communication service frequency bands are mixed according to communication system, And the base station environment is diversified. In order to reduce the cost of operating the base station according to these issues, a base station sharing technology capable of operating various communication systems from a single base station is being commercialized.

1 is a block diagram of a conventional base station system.

1, a base station system 100 basically includes a plurality of base stations (for example, 2G BTS and 3G BTS) 110 and 120 having different communication standards and a plurality of antennas A plurality of antennas 160 and 170 and a plurality of base stations 110 and 120 are provided with a broadband combiner (Multi) antenna 160 and 170 for sharing a base station. band combiner 130 and a coaxial feeder cable 150 for transmitting and receiving an RF signal are formed between the broadband combiner 130 and the broadband combiner 140. [

The core of the base station sharing technology is the broadband combiners 130 and 140. The broadband combiner 130 and 140 have a multitude of L and C resonance cavities in accordance with the frequency characteristics, Or merging multiple signals. The most commonly used resonant cavity filter type is a bandpass filter, which acts to isolate and merge specific 2G, 3G or 4G system signals.

Accordingly, the broadband combiners 130 and 140 can simultaneously support service frequency signals of various communication systems, thereby allowing the coaxial feeder cable 150 to be shared with one another. This has the advantage that the length of the coaxial feeder cable 150 to be used can be reduced and the installation cost of the coaxial feeder cable 150 can be reduced in the tower.

As described above, in the recent base station system 100, a base station sharing technology capable of operating various communication systems in a single base station is being used.

In recent years, attempts have been made to apply a beam tilt control technique to the base station system 100 to minimize signal interference and maximize network capacity in various environments. The base station system 100, which is installed in accordance with the increase in demand for mobile communication services, can overlap the service coverage of each other. For the area where the coverage is overlapped, the beam angle of the base station antennas 160 and 170 Control.

The beam tilting control technique includes a mechanical tilting method in which an operator mechanically tilts the entire antenna and an electric tilting method in which an antenna beam is electrically changed by inserting a phase shifter into the antenna. In recent years, a remote electrical tilting (remote electrical tilting) method for controlling beams of a plurality of antennas at a remote site has been mainly applied in order to reduce the operation cost of the base station (no tower operation) and to manage the beam tilting of the antenna as a whole.

When such remote electric tilting antenna beam control technique is applied to the base station system 100 to which the base station sharing technology is applied, the base station system 100 becomes very complicated and increases installation and operation costs. In particular, as described above, the base station system 100 to which the base station sharing technology is applied is provided with a pair of broadband combiners 130 and 140 at upper and lower ends, and a pair of broadband combiners 130 and 140 A coaxial feeder cable 150 for transmitting and receiving an RF signal is installed in the feeder cable 150. The feeder cable 150 is a device for transmitting and receiving RF signals and a control signal for antenna beam control, (150).

Accordingly, various devices for transmitting a control signal for antenna beam control through the feeder cable 150 must be applied to the base station system 100. In this case, the base station system 100 becomes very complicated and causes an increase in installation and operation costs do.

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above-mentioned problems, and it is an object of the present invention to provide an antenna beam tilting control technique for a multi-band base station system that improves the complexity of a base station system, Band base station system including a base station and a combiner.

Other objects and advantages of the present invention will become apparent from the following description, and it will be understood by those skilled in the art that the present invention is not limited thereto. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to an aspect of the present invention, there is provided a combiner that is provided between a plurality of base stations of a multi-band base station system and a plurality of antennas to enable antenna beam tilt control, A filter unit for separating or merging; And a modem for modulating a digital control signal for antenna beam tilt control into an RF control signal or demodulating an RF control signal for antenna beam tilt control into a digital control signal.

The modulation / demodulation unit may bypass the DC power supplied to the beam controller for antenna beam tilt control.

The filter unit may include a plurality of band-pass filters having different passbands, and capacitors for blocking the DC signals may be connected to both ends of the band-pass filters.

The modulation / demodulation unit may include filtering means for blocking an RF signal of the filter unit from being inputted.

According to another aspect of the present invention, there is provided a multi-band base station system including: a plurality of base stations having different communication standards; A remote controller for outputting a digital control signal for beam tilt control of the base station antenna; A first combiner for merging RF signals output from the plurality of base stations and modulating the digital control signal into an RF control signal; A transmission medium for transmitting the RF signals and the RF control signals of the merged base stations; A second combiner for separating the RF signals of the merged plurality of base stations received from the transmission medium and demodulating the RF control signal into a digital control signal; A beam controller for receiving the demodulated digital control signal from the second combiner and controlling the beam tilt of the base station antenna; And a plurality of base station antennas for transmitting RF signals separated from the second combiner.

The first combiner and the second combiner can bypass DC power supplied from the remote controller and deliver the DC power to the beam controller.

The first combiner and the second combiner include a plurality of band-pass filters having different passbands, and a capacitor for blocking a DC signal is connected to both ends of the band-pass filters .

The present invention is configured to share only one feeder cable and not to include two bias tees separately so as to perform beam tilt control. Therefore, the number of products constituting the base station system can be reduced, thereby simplifying the system and reducing the installation / operation cost.

1 is a block diagram of a conventional base station system.
2 is a block diagram of a base station system according to an embodiment of the present invention.
3 is a diagram illustrating a configuration of a base station system according to another embodiment of the present invention.
4 is a diagram showing an overall signal flow in the base station system of FIG.
5 is a view showing a configuration of the combiner shown in Fig.

The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, in which: There will be. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a base station system according to an embodiment of the present invention, which illustrates a base station system to which a base station sharing technology and a beam tilt control technique are applied.

Referring to FIG. 2, the base station system 200 according to the present embodiment basically includes a plurality of base stations (for example, 2G BTS and 3G BTS) 210 and 220 having different communication standards, And a plurality of antennas 260 and 270 and a plurality of base stations 210 and 220 at the upper end of the plurality of antennas 260 and 270 for sharing a base station. A multi-band combiner 230 and a coaxial feeder cable 250 for transmitting and receiving an RF signal are installed between the broadband combiner 230 and the broadband combiner 230. The coaxial feeder cable is also connected between the broadband combiner 230, 240 and the base stations 210, 220 and between the broadband combiner 230, 240 and the antennas 260, 270.

The core of the base station sharing technology is the broadband combiners 230 and 240. The wide band combiners 230 and 240 have L and C resonance cavities arranged in multiple stages according to the frequency characteristics, It has the ability to separate or merge several signals. The most commonly used resonant cavity filter type is a bandpass filter, which acts to isolate and merge specific 2G, 3G or 4G system signals. Therefore, the broadband combiners 230 and 240 can simultaneously support service frequency signals of various communication systems, thereby sharing the coaxial feeder cable 250 with one another. This has the advantage that the length of the coaxial feeder cable 250 to be used can be reduced and the installation cost of the coaxial feeder cable 250 can be reduced in the tower.

Also. 2, the base station system 200 according to the present embodiment includes a user terminal 310 (e.g., a PC) that provides a graphical user interface (GUI) to provide an operation of a user as an element for beam tilt control, A remote controller 320 connected to the user terminal 310 to generate a control signal (e.g., RS485), and a beam controller (not shown) including a step motor for varying the phase of the beams of the antennas 260 and 270 330, and 340, respectively.

The base station system 200 according to the present embodiment is configured to transmit a digital control signal (RS485 digital signal) generated by the remote controller 320 to an RF signal (OOK_RF_2.17 MHz) at the upper end of the lower broadband combiner 230, And a first Bias Tee 350 for transmitting the modulated signal to the upper broadband combiner 240 through the coaxial feeder cable 250.

The base station system 200 according to the present embodiment demodulates a control signal of an RF signal transmitted through a coaxial feeder cable 250 to a digital control signal at the lower end of the upper broadband combiner 240, 330, and 340, respectively.

2, the remote controller 320 and the first bias tee 350 are connected by an AISG cable as a medium for transmitting a digital control signal and are also connected to a second bias tee 360 and a beam controller 330, 340) is a medium for transmitting digital control signals in a daisy chain manner, and an AISG cable is connected thereto.

In the embodiment of FIG. 2, the base station system 200 applies a base station sharing technology and a beam tilt control technique while sharing only one feeder cable 250. 2, the base station system 200 includes two broadband combiners 230 and 240 and two bias tiers 350 and 360, thereby allowing the system 200 And the installation / operation cost may increase.

3 is a diagram illustrating a configuration of a base station system according to another embodiment of the present invention. In Fig. 3, the same reference numerals as in Fig. 2 include all the functions and operations of the elements in Fig.

3, the base station system 300 of the embodiment with reference to FIG. 3 does not include bias tees 350 and 360 and the combiners 410 and 420 are not shown in FIG. (230, 240) and bias tee (350, 360).

Specifically, the combiners 410 and 420 have a function of separating a signal of a specific band or a function of merging a plurality of signals by constructing L and C resonance cavities in a multistage manner in accordance with frequency characteristics.

The combiner 410 modulates the digital control signal (RS485 digital signal) generated by the remote controller 320 into an RF signal (OOK_RF_2.17 MHz) and outputs the modulated RF signal to the coaxial feeder cable 250 To the upper combiner 420. The combiner 420 demodulates the control signal of the RF signal transmitted through the coaxial feeder cable 250 into a digital control signal and outputs the demodulated digital control signal And the DC voltage to the beam controllers 330 and 340, respectively.

In the embodiment of FIG. 3, the base station system 300 is configured to share only one feeder cable 250 and not to separately include two bias ties, thereby performing beam tilt control. Therefore, compared to the base station system 200 described with reference to FIG. 2, the number of components is reduced, which simplifies the system and reduces the installation / operation cost.

As shown in FIG. 4, an RF signal from a plurality of base stations (BTS 2G / 3G) and a digital control signal (RS 485) transmitted from a remote controller are shown in FIG. 4, ) And DC power are received by the lower combiner. The lower combiner modulates the digital control signal RS485 with the OOK signal (RF signal), bypasses the DC power source, and transmits the modulated OOK signal, the DC power, and the RF signal 2G / 3G to the feeder cable .

The OOK signal, the DC power, and the RF signal (2G / 3G) transmitted through the feeder cable are received by the upper combiner, the upper combiner demodulates the OOK signal into a digital control signal (RS485) And transmits the RF signal (2G / 3G) to the antenna.

5, the combiners 410 and 420 include an RF filter unit 610 and a modem unit 630, as shown in FIG. 5. The combiner 410 and 420 shown in FIG. .

The RF filter unit 610 performs a function of separating RF signals of a specific band or a function of merging various RF signals. Specifically, the RF filter unit 610 includes a band-pass filter 510 for passing an RF signal in a 2G frequency band and a band-pass filter 530 for passing an RF signal in a 3G frequency band.

The RF signal from the 2G base station 210 is transmitted through the port 1 to the 2G antenna 260 through the bandpass filter 510 and the feeder cable and is received through the feeder cable The RF signal is transmitted to the 2G base station 210 through the band-pass filter 510 and port 1.

The RF signal from the 3G base station 230 is transmitted through the port 2 through the bandpass filter 530 to the 2G antenna 270 via the feeder cable and the RF signal received through the feeder cable The RF signal is passed through the band-pass filter 530 and port 2 to the 3G base station 230.

Capacitors are connected to both ends of the band-pass filters 510 and 530 to block DC power or the like from passing through the band-pass filters 510 and 530.

The modem unit 630 includes a microprocessor unit (MPU) 550, a stabilizer 570, a regulator 590, and a coil 580 as control means.

The microprocessor unit 550 controls signal demodulation and demodulation of the modem unit 630 and bypass operation of the DC power supply.

The stabilizer 570 turns DC power coming from the AISG signal port into a specific DC power source. The DC power source through the stabilizer 570 is transmitted through the coil 580 and the feeder cable.

The modem 590 modulates the digital control signal RS485 input from the AISG signal port into an RF control signal (i.e., an OOK signal) and transmits the RF control signal (that is, OOK ) To a digital control signal (RS485) and transmits it to the AISG signal port.

The coil 580 passes only a frequency signal of 3 MHz or less as a filtering means for filtering a high frequency signal. That is, the RF control signal (i.e., the OOK signal) passes through the coil 580 as a 2.17 MHz signal and blocks the commercial communication RF signal such as 2G or 3G to protect the modulation / demodulation unit 630.

While the specification contains many features, such features should not be construed as limiting the scope of the invention or the scope of the claims. In addition, the features described in the individual embodiments herein may be combined and implemented in a single embodiment. Conversely, various features described herein in a single embodiment may be implemented in various embodiments individually or in a suitable subcombination.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings.

210, 230: base station 260, 270: base station antenna
410, 420: Combiner 250: Feeder cable
320: remote controller 340: beam controller
310: control terminal

Claims (7)

A combiner installed on a plurality of base stations of a multi-band base station system and provided on a plurality of antennas to be connected to one transmission medium to enable antenna beam tilt control,
A filter unit for separating or merging RF signals of a plurality of frequency bands; And
And a modem for modulating a digital control signal for antenna beam tilt control into an RF control signal or demodulating an RF control signal for antenna beam tilt control into a digital control signal,
Wherein the modulation /
A stabilizer for turning DC power supplied from a remote controller to a specific DC power source and supplying the DC power to a beam controller for antenna beam tilt control;
A modem for modulating the digital control signal into the RF control signal or demodulating the RF control signal into the digital control signal; And
And a coil for blocking the RF signal of the filter unit from passing therethrough and allowing the specific DC power source and the RF control signal to pass therethrough. delete The method according to claim 1,
The filter unit includes:
And a plurality of band-pass filters having different passbands, and capacitors for blocking the DC signals are connected to both ends of the band-pass filters. delete A plurality of base stations of different communication standards;
A remote controller for outputting a digital control signal for beam tilt control of the base station antenna;
A first combiner for merging RF signals output from the plurality of base stations and modulating the digital control signal into an RF control signal;
A transmission medium for transmitting the RF signals and the RF control signals of the merged base stations;
A second combiner for separating the RF signals of the merged plurality of base stations received from the transmission medium and demodulating the RF control signal into a digital control signal;
A beam controller for receiving the demodulated digital control signal from the second combiner and controlling the beam tilt of the base station antenna; And
And a plurality of base station antennas for transmitting RF signals separated from the second combiner,
The first and second combiners may include:
A filter unit for separating or merging the RF signal; And
Demodulating unit,
Wherein the modulation /
A stabilizer for converting a DC power input from the remote controller into a specific DC power source and supplying the DC power to the beam controller;
A modem for modulating the digital control signal into the RF control signal or demodulating the RF control signal into the digital control signal; And
And a coil for blocking the RF signal of the filter unit from passing therethrough but passing the specific DC power source and the RF control signal. delete 6. The method of claim 5,
Wherein the first combiner and the second combiner comprise:
And a plurality of band-pass filters having different passbands, and capacitors for blocking the DC signals are connected to both ends of the band-pass filters.

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