KR20090116112A - Method for controlling transmitting/receiving operation of separated-type base station, and a digital unit and a separated-type base station for supporting the same - Google Patents

Abstract

PURPOSE: A transmission/reception operation control method, a digital unit supporting the same and a separated base station capable of controlling transmission/reception operation according to channel wideband applied a remote RF unit. CONSTITUTION: A DU(Digital Unit) periodically monitors a connection state with an RRU(Remote Radio Frequency Unit)(S502). If the digital unit receives channel bandwidth information, the channel bandwidth information is confirmed. Synchronization signal is generated by an oscillation frequency adjustment(S506). The clock based on the synchronizing signal is generated(S508). The transmission/reception operation is controlled in order to the modulation/demodulation process of IQ signal(S510).

Description

Method for controlling transmission and reception operations in a separate base station, and a digital unit and a separate base station supporting the same {Method for Controlling Transmitting / Receiving Operation of Separated-type Base Station, and a Digital Unit and a Separated-type Base Station for Supporting the Same}

The present invention relates to a method for controlling transmission and reception operations in a separate base station, and a digital unit and a separate base station supporting the same, and more particularly, according to a channel bandwidth applied to a remote RF unit of a separate base station. The present invention relates to a method for controlling a transmission / reception operation in a digital unit, a digital unit supporting the same, and a detachable base station.

In general, if a general base station is installed in an area of a relatively small number of subscribers compared to the number of subscribers covered by the base station, waste is generated. In such an area, a remote RF unit (RRU) is installed and wasteful. The factor will be removed beforehand.

The separate base station is composed of a remote RF unit (RRU) and a digital unit (DU). The RRU receives the baseband transmit IQ signal, performs IF signal processing and RF signal processing, and transmits a signal to the terminal through an antenna. The RRU receives the RF signal, performs RF signal processing and IF signal processing, and transmits a baseband IQ signal to the digital unit DU. The DU is responsible for the control and operation of the entire base station, and transmits and receives baseband digital I / Q signals by processing MAC and PHY signals of data frames.

However, SARU filters, BPFs, LPFs, and high-power amplifiers of RRUs have various limitations in terms of device design or satisfactory implementation in order to have frequency characteristics required for RF processing. Therefore, the RRU is not easy to operate to be compatible with various channel bandwidths of communication channels such as WiBro and WiMAX.

Therefore, in the case of a general detachable base station, the operator replaces the board of the DU or manually changes the configuration according to the channel bandwidth applied to the RRU and the frequency of the signal processed by the RRU.

For the above reasons, the operator of the DU has to recognize the channel bandwidth applied to the RRU before operating the system, and there is a problem in that the synchronization signal according to the channel bandwidth is changed or the board of the DU needs to be replaced.

In addition, there is a difficulty in changing the parameters related to the transmission and reception control of the signal by running software corresponding to the channel bandwidth before operating the system.

In addition, if the channel bandwidth applied to the prepared DU and RU is different, it is necessary to change the board and restart the operating software accordingly. There was a problem in that the efficiency and economical efficiency of the test configuration was reduced because of participation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and a method for controlling a transmission / reception operation without replacing or manually setting a board of a digital unit (DU) according to a channel bandwidth applied to a remote RF unit (RRU), a digital unit and It is a technical problem to provide a separate base station.

In addition, another object of the present invention is to clearly provide a method and procedure for operating a software and a synchronization signal required for controlling a transmission / reception operation according to a channel bandwidth.

In addition, it is another technical problem to provide a transmission and reception operation control method, a digital unit and a separate base station to improve the efficiency and economics of the test environment for various channel bandwidths.

According to an aspect of the present invention, there is provided a method for controlling transmission and reception signals in a separate base station in the digital unit of the separate base station including a separate digital unit and a remote RF unit. A method of controlling a transmission / reception operation, the method comprising: receiving channel bandwidth information being used in a remote RF unit among a plurality of channel bandwidths available in the remote RF unit performing RF (Radio Frequency) processing of the separate base station; Confirming the received channel bandwidth information and generating a synchronization signal by adjusting an oscillation frequency corresponding to the identified channel bandwidth information; And controlling the transmission / reception operation so that modulation / demodulation processing of the IQ signal of the separate base station is performed in the transmission / reception operation environment corresponding to the identified channel bandwidth information by using the synchronization signal.

According to another aspect of the present invention, there is provided a method of controlling a transmission / reception signal in a separate base station in a method of controlling a transmission / reception operation in the remote RF unit of a separate base station including a separate digital unit and a remote RF unit. Receiving, from the digital unit, a request for providing channel bandwidth information being used in the remote RF unit among a plurality of channel bandwidths available in the remote RF unit performing RF processing of the detached base station; And transmitting the channel bandwidth information to the digital unit so that the IQ signal of the split base station is modulated and demodulated in a transmission / reception operation environment corresponding to the channel bandwidth information according to the request.

A digital unit according to an aspect of the present invention for achieving the above object is in the digital unit of a separate base station comprising a separate digital unit and a remote RF unit, the remote RF unit for performing RF processing of the separate base station A main control unit for checking the channel bandwidth information being used in the remote RF unit among the plurality of channel bandwidths available in the remote RF unit, and generating a synchronization signal by adjusting an oscillation frequency corresponding to the checked channel bandwidth information; A digital processor for controlling a transmission / reception operation such that modulation and demodulation processing of the IQ signal of the separate base station is performed in the transmission / reception operation environment corresponding to the identified channel bandwidth information by using the synchronization signal; And an interface unit configured to control the transmission / reception operation on the interface of the IQ signal with the remote RF unit using the identified channel bandwidth information and the synchronization signal.

A separate base station according to an aspect of the present invention for achieving the above object is a separate base station comprising a digital unit and a remote RF unit, a plurality of channels available in the remote RF unit performing the RF processing of the separate base station A remote RF unit which provides channel digital channel information being used in the remote RF unit of the bandwidth to the digital unit; And confirming the received channel bandwidth information, generating a synchronization signal by adjusting an oscillation frequency corresponding to the identified channel bandwidth information, and using the synchronization signal in a transmission / reception operation environment corresponding to the identified channel bandwidth information. And a digital unit for controlling a transmission / reception operation so that modulation and demodulation processing of the IQ signal of the separate base station is performed.

As described above, according to the present invention, the digital unit (DU) automatically recognizes the channel bandwidth applied to the remote RF unit (RRU) and automatically sets parameters necessary for the control of the transmission / reception signal, thereby operating convenience of the separate base station. There is an effect to increase.

In addition, according to the present invention, there is an effect of clearly providing a software and synchronization signal varying procedure corresponding to the channel bandwidth applied to the RRU to drive the base station system.

In addition, according to the present invention, it is possible to interwork with RUs using different channel bandwidths in the same DU and to minimize the adaptation process to the channel bandwidth of the DU to increase the efficiency and economic efficiency of the base station test environment for various channel bandwidths have.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram schematically illustrating a detachable base station according to an embodiment of the present invention, which includes a digital unit 102 and a remote radio frequency unit 116. Hereinafter, in one embodiment, the detachable base station will be described as a detachable base station of a WiBro network.

The digital unit (DU: 102), the DU 102 is the main control unit 104, digital processing unit 106, serial-to-parallel conversion unit 108, interface unit 110, L3 switch unit 112 and GPS antenna 114 It is in charge of the digital processing of the signal transmitted and received between the separate base station and the terminal (not shown) and transmits and receives a baseband digital IQ signal with a remote RF unit (RRU) (116). In addition, the entire base station is responsible for the control and operation.

The main controller 104 is responsible for generating and distributing a synchronization signal of the separate base station based on the signal received from the GPS antenna 114 to each internal component, and controlling and operating the entire separated base station system.

When receiving the channel bandwidth information being used by the RRU 116 of the plurality of channel bandwidths available from the RRU 116 from the RRU 116, the received channel bandwidth information is checked and corresponding to the checked channel bandwidth information. A synchronization signal is generated by oscillation frequency adjustment, and the channel bandwidth information is notified to the digital processing unit 106 and the interface unit 110 via the L3 switch unit 112.

In one embodiment, the main control unit 104 is a base unit controller (not shown) and the clock unit (not shown) is a combination of control, resource allocation, call processing, base station management (RAS Management) for the internal components of the base station Or a main control and clock unit (MCCU) including an RMP (RAS Management Processor), which is a processor that controls the overall operation of the base station such as control station interfacing.

Hereinafter, the main control unit 104 will be described in detail with reference to FIG. 2.

FIG. 2 is a block diagram schematically illustrating a main controller 104 according to an embodiment of the present invention, wherein the main controller 104 includes a main processor 202, a frequency controlled crystal oscillator (FCXO), and a TDD synchronization generator. The unit 210 and the GPS receiver 212.

The main processor 202 includes a channel bandwidth notification unit 204 and a synchronization signal control unit 206, requests and notifies channel bandwidth information applied to the RRU 116, and controls the synchronization signal of the separate base station.

When the main processor 202 receives a notification from the interface unit 110 that the RRU 116 is connected to the DU 102, the RRU 116 via the L3 switch unit 112 and the interface unit 110. The RRU control / interface unit 118 requests configuration information of the RRU 116. As a result of the request, the main processor 202 receives the configuration information of the RRU 116 from the RRU control / interface 118, and the configuration information of the RRU 116 is applied to the RRU 116. Channel bandwidth information is included.

The channel bandwidth information includes a channel bandwidth defined in IEEE 802.16e and indicates a channel bandwidth that can be applied in a WiBro network. In one embodiment, the channel bandwidth information that can be applied to the RRU 116 according to an embodiment of the present invention is any one of 1.25MHz, 3.5MHz, 7MHz, 8.75MHz, 10MHz, 14MHz, 17.5MHz, 20MHz and 28MHz Can be.

Therefore, although the channel bandwidth applied to the RRU 116 may vary, hereinafter, the channel bandwidth information applied to the RRU 116 will be described as a first channel bandwidth. In addition, although the DU 102 may perform digital processing of a transmission / reception signal by varying according to the various channel bandwidths, the channel bandwidth information preset and applied to the DU 102 will be described as a second channel bandwidth.

The channel bandwidth notification unit 204 recognizes the channel bandwidth information from the environment setting information of the RRU 116 received from the RRU control / interface unit 118. That is, it is recognized that the channel bandwidth used by the RRU 116 is the first channel bandwidth. At this time, since the channel bandwidth currently applied to the DU 102 is the second channel bandwidth, it is necessary to change the channel bandwidth to be applied to the DU 102 later to the first bandwidth.

The channel bandwidth notification unit 204 uses the digital processing unit 106 and the interface via the L3 switch unit 112 to determine that the channel bandwidth applied to the RRU 116 is the first channel bandwidth for changing the above-described setting of the channel bandwidth. The unit 110 notifies.

The synchronization signal controller 206 controls generation of a synchronization signal that varies according to channel bandwidth information applied to the RRU 116. In one embodiment, the synchronization signal may be a system reference clock (SYSCLK) or a TDD synchronization signal that varies according to channel bandwidth information.

For example, when the first channel bandwidth is 8.75 MHz and the second channel bandwidth is 10 MHz, the frequency of the system reference clock of the DU 102 corresponding to the first channel bandwidth is 10 MHz. And, the frequency of the system reference clock of the DU 102 corresponding to the second channel bandwidth is 11.2 MHz. At this time, since the DU 102 should operate in accordance with the first channel bandwidth applied to the RRU 116, the synchronization signal controller 206 may adjust the oscillation frequency corresponding to the channel bandwidth information of which the FCXO 208 is confirmed. Control to generate a system reference clock of 10 MHz.

The FCXO 208 is a device for controlling stable frequency by using a built-in Voltage Controlled Crystal Oscillator (VCXO) circuit, and generates a system reference clock according to channel bandwidth control performed by the synchronization signal controller 206. The system reference clock generated by the FCXO 208 is distributed to the components of the separate base station including the digital processing unit 106 and the interface unit 110 to become a reference signal for base station synchronization.

The TDD sync generator 210 receives a system reference clock received from the FCXO 208 and a 1 pulse per second (PPS) signal received from the GPS receiver 212 to generate a TDD sync signal for reference of the base station.

The GPS receiver 212 generates a 1PPS signal using the signal received by the GPS antenna 114 under the control of the main processor 202.

Referring back to FIG. 1, the digital processor 106 performs modulation and demodulation processing of the IQ signal of the separate base station in a transmission / reception operation environment corresponding to the channel bandwidth information identified using the synchronization signal generated by the synchronization signal controller 206. Control transmission and reception operations to be performed.

That is, the digital processor 106 performs digital signal processing related to modulation and demodulation of the MAC and PHY layers of the WiBro system to generate a baseband digital IQ signal from the DU 102 to the RRU 116. The RRU 116 receives and processes the baseband digital IQ signal toward the DU 102. The digital processor 106 controls transmission and reception operations for digital signal processing related to modulation and demodulation by using channel bandwidth information applied to the RRU 116 and a corresponding synchronization signal.

Hereinafter, the digital processing unit 106 will be described in detail with reference to FIG. 3.

3 is a block diagram schematically illustrating a digital processing unit 106 according to an embodiment of the present invention. The digital processing unit 106 may include a digital processing processor unit 302, a first memory unit 308, and a first clock generation unit. The unit 310 and the modem unit 312 is included.

In one embodiment, the digital processing unit 106 is a block for processing a MAC / PHY modem, data randomization, convolution / convolution-turbo channel coding / decoding, interleaving (Interleaving), FUSC / PUSC It may be a DCCU (Digital Channel Card Unit) that performs a function such as subchannel allocation.

The digital processing processor unit 302 is in charge of the overall operation and control of the digital processing unit 106 and includes a first clock control unit 304 and a modem control unit 306.

When the digital processing processor 302 receives the channel bandwidth information applied to the RRU 116 from the main processor 202, the digital processing processor 302 performs corresponding clock and modem control.

The first clock controller 304 controls generation of a first reference clock based on a synchronization signal that is a system reference signal according to channel bandwidth information applied to the RRU 116.

For example, when the first channel bandwidth applied to the RRU 116 is 8.75 MHz, and a system reference clock of 10 MHz is generated in the main controller 104 accordingly, the first clock controller 304 may include a first clock generator. The control unit 310 controls the modem unit 312 to provide a 108 MHz clock generated based on the 10 MHz system reference clock. The 108 MHz clock is a clock required by the modem unit 312 for digital processing of a corresponding transmission / reception signal when the channel bandwidth is the first channel bandwidth.

The modem controller 306 controls the transmission / reception signal for digital signal processing related to modulation / demodulation by the transmission / reception operation environment setting determined by the received channel bandwidth information and the timing determined by the first reference clock. That is, the transmission / reception operation for the modulation / demodulation processing of the digital IQ signal is controlled by the transmission / reception operation environment setting determined by the confirmed channel bandwidth information and the timing determined by the first reference clock generated by the first clock control unit 304. do.

When the modem controller 306 receives the channel bandwidth information applied to the RRU 116 from the main controller 104, the modem controller 306 downloads source code related to the transmission / reception operation configuration corresponding thereto from the first memory unit 308. The modem unit 312 controls the transmission / reception operation environment according to the channel bandwidth information according to the source code.

In one embodiment, the transmission and reception operation configuration is a symbol period of the transmission and reception signal, the symbol ratio of the uplink and downlink frame, FFT size, the number of subcarriers, the number of sub-channels and over It may be a setting for a parameter including at least one of the sampling rates.

The modem controller 306 receives the first reference clock generated according to the channel bandwidth information and controls the modem unit 312 to perform an orthogonal frequency-division multiple access (OFDMA) modem function at a corresponding timing.

For example, when the first channel bandwidth applied to the RRU 116 is 8.75 MHz, the modem controller 306 causes the modem unit 312 to cause the symbol ratio of the downlink frame and the uplink frame to be "27:15". Control to use timing and related parameters.

Various parameters, such as the symbol ratio of the downlink frame and the uplink frame described above, depend on the channel bandwidth. In one embodiment of the present invention, the digital processing processor 302 automatically recognizes the required channel bandwidth through the channel bandwidth information received from the RRU 116, and performs corresponding first reference clock generation and modem control. Operation convenience of the separate base station is increased.

In addition, according to the present invention, the DU 102 can perform software and synchronization signal variation corresponding to the channel bandwidth applied to the RRU 116 by the above-described procedure.

The first memory unit 308 stores transmission and reception environment settings for each channel bandwidth used by the digital processor 106 for various channel bandwidths.

The first clock generator 310 generates a first reference clock based on a synchronization signal that is a system reference signal according to channel bandwidth information applied to the RRU 116 under the control of the first clock controller 304. In an exemplary embodiment, the first clock generator 310 may set the first reference clock using a phase locked loop (PLL) that inputs a system reference signal according to channel bandwidth control of the first clock controller 304. Can be generated.

The modem unit 312 performs digital signal processing related to modulation and demodulation processing of the IQ signal according to the first reference clock and the transmission / reception operation environment setting according to the channel bandwidth information applied to the RRU 116. In one embodiment, the modem unit 312 performs an OFDMA modem function for the MAC and PHY layer of the WiBro system.

Referring back to FIG. 1, the serial-to-parallel conversion unit 106 performs serial-to-parallel conversion (SERDES) on the transmission / reception IQ signal between the digital processing unit 106 and the interface unit 110.

The interface unit 110 is responsible for the interface between the RRU 116 and the DU 102 connected to the optical cable 128 by converting the transmission and reception IQ signal CPRI (Common Public Radio Interface). In addition, between the RRU 116 and the DU 102, the DU 102 transmits a message and a response, which are requested to know the channel bandwidth information and the configuration information of the RRU 116, using an Ethernet frame. . Here, the response includes channel bandwidth information applied to the RRU 116.

Hereinafter, the interface unit 110 will be described in detail with reference to FIG. 4.

4 is a block diagram schematically illustrating an interface unit 110 according to an embodiment of the present invention. The interface unit 110 includes an interface processor unit 402, a second memory unit 408, and a second clock generator. 410, a CPRI converter 412, and an E / O converter 414.

The interface processor unit 402 periodically monitors the connection state between the RRU 116 and the DU 102, and notifies the main controller 104 of the monitoring result when the RRU 116 is connected. At this time, the main controller 104 requests the RRU 116 to provide channel bandwidth information according to the notification. In addition, the request for providing the channel bandwidth information is included in the request for configuration information of the RRU 116.

The interface processor unit 402 is in charge of the overall operation and control of the interface unit 110 and includes a second clock control unit 404 and a CPRI conversion control unit 406.

When the interface processor unit 402 receives channel bandwidth information applied to the RRU 116 received from the main processor unit 202, the interface processor unit 402 controls the interface between the corresponding DU 102 and the RRU 116. The channel bandwidth information is received via the L3 switch unit 112 via Ethernet.

The second clock controller 404 controls generation of a second reference clock based on a synchronization signal that is a system reference signal according to channel bandwidth information applied to the RRU 116.

For example, when the first channel bandwidth applied to the RRU 116 is 8.75 MHz, and a system reference clock of 10 MHz is generated in the main controller 104 accordingly, the second clock controller 404 may include the second clock generator. The control unit 410 controls the CPRI converter 412 to provide the 61.44 MHz second reference clock generated based on the 10 MHz system reference clock. Here, the 61.44 MHz clock is a clock required for the CPRI converter 412 to perform the corresponding interface regardless of the frequency or channel bandwidth of the system reference clock.

That is, the second clock controller 404 controls the second clock generator 410 to generate the second reference clock of a constant frequency regardless of the system reference clock that varies according to the channel bandwidth applied to the RRU 116. .

The CPRI conversion controller 406 controls the transmission / reception signal with respect to the interface with the RRU 116 according to the transmission / reception operation environment setting determined by the received channel bandwidth information and the timing determined by the second reference clock.

When the CPRI conversion control unit 406 receives the channel bandwidth information applied to the RRU 116 from the main control unit 104, the CPRI conversion control unit 406 receives the source code related to the transmission / reception operation environment setting of the interface unit 110 corresponding thereto. 408). The CPRI converter 412 controls the transmission / reception operation environment according to the channel bandwidth information according to the source code.

The CPRI conversion control unit 406 controls the CPRI conversion unit 412 to receive the second reference clock generated according to the channel bandwidth information and perform CPRI conversion according to the corresponding timing.

For example, when the first channel bandwidth applied to the RRU 116 is 8.75 MHz, the CPRI conversion controller 406 controls the CPRI converter 412 to generate a CRPI frame corresponding to the 8.75 MHz channel bandwidth.

CPRI conversion control unit 406 according to an embodiment of the present invention controls the CRPI conversion using the CPRI standard. Here, the CPRI standard is proposed by various companies with respect to a main interface inside a wireless base station for portable communication, and is widely used in an industry related to an interface, and provides a general standard for a main interface inside a base station.

The second memory unit 408 stores a transmission / reception operation environment for each channel bandwidth used by the interface unit 110 for various channel bandwidths.

The second clock generator 410 generates a second reference clock based on a synchronization signal that is a system reference signal according to channel bandwidth information applied to the RRU 116 under the control of the second clock controller 404. According to an exemplary embodiment, the second clock generator 410 may generate a second reference clock using a PLL that inputs a system reference signal according to voltage control for each channel bandwidth of the second clock controller 404. .

The CPRI converter 412 may perform CPRI on a signal between the digital processor 106 and the RRU control / interface unit 118 according to a second reference clock and transmit / receive operation configuration according to channel bandwidth information applied to the RRU 116. Perform the conversion. Here, the transmission and reception operation environment setting is obtained by the CPRI conversion control unit 406 from the second memory unit 408 according to the channel bandwidth information for the interface between the DU 102 and the RRU 116.

The E / O converter 414 converts the CRPI-converted signal into an electrical to optical signal so that it can be transmitted through the optical cable 128.

Referring back to FIG. 1, the L3 switch unit 112 forms an Ethernet connection path between the main control unit 104, the digital processing unit 106, and the interface unit 110 within the DU 102. In addition, it performs IP communication with a control station (ACR) (not shown), and serves as a transmission / reception path for traffic data and control information related to the separate base station and the control station.

The RRU 116 includes an RRU control / interface unit 118, a DUC / DDC unit 120, a DAC / ADC unit 122, and an RF processing unit 124, and transmits and receives signals between the DU 102 and the terminal. It is responsible for intermediate frequency conversion, digital to analog converting of transmission signal, analog to digital converting of received signal, and RF processing of transmission and reception signals. In addition, the channel bandwidth information of the RRU 116 is provided to the DU 102 so that the transmission and reception signals are controlled by the DU 102 by the channel bandwidth information.

The RRU control / interface unit 118 is responsible for the control and operation of the RRU 116, and communicates with the interface unit 110 of the DU 102 using CPRI standards through internal CRPI conversion means.

When the configuration information of the RRU 116 is requested from the DU 102, the configuration information including the channel bandwidth information of the RRU 116 is provided to the DU 102. That is, when delivering configuration information to the DU 102, it notifies whether the channel bandwidth information of the RRU 116 is the first channel bandwidth or the second channel bandwidth. Here, the configuration information refers to the general configuration information for the RRU 116 to communicate as an RF device according to IEEE 802.16e.

The RRU control / interface unit 118 transmits environment setting information including channel bandwidth information to the DU 102 using an Ethernet frame.

The DUC / DDC unit 120 uses a digital up converter (not shown) to increase the sampling frequency of the transmission IQ signal and perform frequency up-conversion. A sampling down is performed on the received IQ signal using a digital down converter (not shown), and frequency down conversion is performed. This is for the conversion between the baseband IQ signal and the intermediate frequency (IF) IQ signal.

The DAC / ADC unit 122 is responsible for the DA conversion of the transmission signal directed to the terminal and the AD conversion of the reception signal received from the terminal.

The RF processor 124 is in charge of RF processing for the transmitted and received signals, and amplifies a high power output signal and a low noise amplification signal received from the terminal through the RF antenna 126. In addition, a TDD switch means for performing temporal switching on the transmitted and received signals is provided. It also includes a SAW filter that can pick out only the desired frequency components of a specific bandwidth for the received signal.

5 is a flowchart illustrating a method for controlling transmission / reception in a digital unit of a detachable base station according to an embodiment of the present invention.

First, the digital unit DU periodically monitors the connection state with the remote RF unit RRU (S502).

Next, when the RRU is connected, the RRU requests to provide the channel bandwidth information that the RRU is using among the plurality of channel bandwidths available to the RRU (S504). Here, the request for providing the channel bandwidth information may be included in the request for configuration information of the RRU.

In one embodiment, the channel bandwidth information may include a channel bandwidth defined in IEEE 802.16e.

Next, when the request result DU is provided with the channel bandwidth information, confirm the channel bandwidth information received from the DU, and generates a synchronization signal by adjusting the oscillation frequency corresponding to the confirmed channel bandwidth information (S506).

In one embodiment, channel bandwidth information may be sent by an Ethernet frame from the RRU to the DU. Here, the channel bandwidth information is transmitted by the Ethernet frame not only between the DU and the RU, but also between components within the DU.

In one embodiment, the synchronization signal may be a system reference clock or a TDD synchronization signal that varies according to channel bandwidth information.

Next, a clock based on a synchronization signal is generated according to the channel bandwidth information checked in the DU (S508).

Next, the transmission and reception operation is controlled such that modulation and demodulation processing of the IQ signal of the separate base station is performed according to the transmission and reception operation environment setting determined by the channel bandwidth information and the timing determined by the clock (S510).

In one embodiment, the transmission and reception operation configuration is at least one of the symbol period of the transmission and reception signal, the symbol ratio of the uplink and downlink frame, the Fast Fourier Transform (FFT) size, the number of subcarriers, the number of sub-channels and the over sampling rate It may be a setting for a parameter including one.

In one embodiment, the transmission and reception operation environment setting may be set according to the source code associated with the channel bandwidth obtained from the memory.

In one embodiment, the transmission and reception operation may be controlled by performing the demodulation process by timing of the first clock generated based on the identified channel bandwidth information and the synchronization signal.

In one embodiment, the method further comprises generating a second clock based on the identified channel bandwidth information and the synchronization signal and interfacing the IQ signal with the RRU according to the timing determined by the confirmed channel bandwidth information and the second clock. can do. Here, the transmission / reception signal may be interfaced with the RRU using a common public radio interface (CPRI) standard.

6 is a flowchart illustrating a method for controlling transmission / reception in a remote RF unit of a detachable base station according to an embodiment of the present invention.

First, a request for providing channel bandwidth information being used in an RRU from among a plurality of channel bandwidths available in an RRU performing RF processing of the detached base station is received from a DU (S602).

Next, the channel bandwidth information being used in the RRU is transmitted to the DU so that the IQ signal of the separate base station is modulated and demodulated in the transmission / reception operation environment corresponding to the channel bandwidth information (S604).

In one embodiment, the channel bandwidth information may be sent to the DU by an Ethernet frame. In one embodiment, the channel bandwidth information may be included in the configuration information of the RRU and transmitted to the DU.

Those skilled in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features.

Therefore, it is to be understood that the embodiments described above are exemplary in all respects and not restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

1 is a block diagram schematically illustrating a separate base station according to an embodiment of the present invention.

Figure 2 is a block diagram schematically showing a main control portion according to an embodiment of the present invention.

3 is a block diagram schematically illustrating a digital processing unit according to an embodiment of the present invention.

Figure 4 is a block diagram schematically showing an interface unit according to an embodiment of the present invention.

5 is a flowchart illustrating a method for controlling transmission / reception in a digital unit of a detachable base station according to an embodiment of the present invention.

6 is a flowchart illustrating a transmission and reception operation control method in a remote RF unit of a detachable base station according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

102: digital unit 104: main controller

106: digital processing unit 108: serial-parallel conversion unit

110: interface unit 112: L3 switch unit

114: GPS antenna 116: remote RF unit

118: RRU control / interface unit 120: DUC / DDC unit

122: DAC / ADC unit 124: RF processing unit

Claims (23)

A method of controlling a transmission / reception operation in the digital unit of a separate base station including a separate digital unit and a remote RF unit, the method comprising: Receiving channel bandwidth information being used in the remote RF unit among a plurality of channel bandwidths available in the remote RF unit performing RF (Radio Frequency) processing of the detached base station; Identifying the received channel bandwidth information and generating a synchronization signal by adjusting an oscillation frequency corresponding to the identified channel bandwidth information; And Controlling a transmission / reception operation so that modulation and demodulation processing of the IQ signal of the separate base station is performed in the transmission / reception operation environment corresponding to the identified channel bandwidth information using the synchronization signal; Transmitting and receiving operation control method in a separate base station comprising a. The method of claim 1, wherein receiving the channel bandwidth information comprises: Periodically monitoring a connection state with the remote RF unit; And As a result of the monitoring, when the remote RF unit is connected, requesting the remote RF unit to provide channel bandwidth information being used in the remote RF unit; Transmitting and receiving operation control method in a separate base station comprising a. The method of claim 1, wherein the controlling of the transmission / reception operation comprises: Generating a clock based on the synchronization signal according to the identified channel bandwidth information; And Controlling the transmission / reception operation so that modulation / demodulation processing of the IQ signal of the separate base station is performed according to a transmission / reception operation environment setting determined by the channel bandwidth information and a timing determined by the clock; Transmitting and receiving operation control method in a separate base station comprising a. The method of claim 3, wherein the transmission and reception operation environment setting, A setting for a transmission / reception parameter including at least one of a symbol period of the IQ signal, a symbol ratio of uplink and downlink frames, a fast fourier transform (FFT) size, a number of subcarriers, a number of subchannels, and an oversampling ratio; Transmitting and receiving operation control method in a separate base station, characterized in that. The method of claim 3, wherein the transmission and reception operation environment setting, Transmitting and receiving operation control method in a separate base station, characterized in that the set by the source code obtained from the memory corresponding to the confirmed channel bandwidth information. The method of claim 1, wherein the transmission and reception operation, And the modulation and demodulation process is controlled by the timing of the first clock generated based on the identified channel bandwidth information and the synchronization signal. The method of claim 1, And controlling a transmission / reception operation by performing an interface with the remote RF unit of the IQ signal by timing of a second clock generated based on the identified channel bandwidth information and the synchronization signal. Transmitting and receiving operation control method in a separate base station. The method of claim 7, wherein the interface, Transmitting and receiving operation control method in a separate base station, characterized by using the Common Public Radio Interface (CPRI) standard. The method of claim 1, wherein the synchronization signal, Transmitting and receiving operation control method in a separate base station, characterized in that the system reference clock or TDD synchronization signal that is variable according to the identified channel bandwidth information. A method of controlling a transmission / reception operation in the remote RF unit of a separate base station including a separate digital unit and a remote RF unit, the method comprising: Receiving from the digital unit a request for providing channel bandwidth information being used in the remote RF unit among a plurality of channel bandwidths available in the remote RF unit performing RF processing of the detached base station; In response to the request, transmitting the channel bandwidth information to the digital unit to modulate and demodulate the IQ signal of the separate base station in a transmission / reception operation environment corresponding to the channel bandwidth information; Transmitting and receiving operation control method in a separate base station comprising a. The method of claim 10, wherein the channel bandwidth information, Transmitting and receiving operation control method in a separate base station, characterized in that transmitted to the digital unit by the Ethernet frame. The method of claim 10, wherein the channel bandwidth information, According to the request, it is included in the configuration information of the remote RF unit and transmitted to the digital unit characterized in that the transmission and reception operation control method in a separate base station. In the digital unit of a separate base station comprising a separate digital unit and a remote RF unit, From the remote RF unit performing the RF processing of the detached base station, checking the channel bandwidth information being used in the remote RF unit among the plurality of channel bandwidths available in the remote RF unit, and oscillating corresponding to the confirmed channel bandwidth information. A main control unit for generating a synchronization signal by frequency adjustment; A digital processor for controlling a transmission / reception operation such that modulation and demodulation processing of the IQ signal of the separate base station is performed in the transmission / reception operation environment corresponding to the identified channel bandwidth information by using the synchronization signal; And An interface unit for controlling the transmission / reception operation on the interface of the IQ signal with the remote RF unit using the identified channel bandwidth information and the synchronization signal; Digital unit comprising a. The method of claim 13, wherein the interface unit, Periodically monitoring the connection state with the remote RF unit, and notifying the main control unit of the monitoring result when the remote RF unit is connected, And the main control unit requests the remote RF unit to provide channel bandwidth information being used in the remote RF unit according to the notification. The method of claim 13, wherein the main control unit, A synchronization signal controller for controlling generation of a synchronization signal that is varied by adjusting an oscillation frequency corresponding to the identified channel bandwidth information; And A channel bandwidth notification unit for notifying the digital channel processing unit and the interface unit of the checked channel bandwidth information; Digital unit comprising a. The method of claim 13, wherein the digital processing unit, A first clock controller configured to control generation of a first clock based on the synchronization signal according to the identified channel bandwidth information; And A modem controller for controlling a transmission / reception operation for the modulation / demodulation process based on a transmission / reception operation environment setting determined by the checked channel bandwidth information and a timing determined by the first clock; Digital unit comprising a. The method of claim 16, wherein the transmission and reception operation environment setting, For a parameter including at least one of a symbol period of the transmission / reception signal, a symbol ratio of uplink and downlink frames, an FFT size, a number of subcarriers, a number of subchannels, and an oversampling rate varying according to the channel bandwidth information Digital unit, characterized in that the setting. The method of claim 16, wherein the transmission and reception operation environment setting, And a source code obtained from a memory corresponding to the checked channel bandwidth information. The method of claim 13, wherein the interface unit, A second clock controller configured to control generation of a second clock based on the synchronization signal according to the channel bandwidth information; And An interface controller configured to control a transmission / reception operation for the interface according to a transmission / reception operation environment setting determined by the channel bandwidth information and a timing determined by the second clock; Digital unit comprising a. The method of claim 13, wherein the interface unit, A digital unit for controlling the transmission and reception of the interface using a CPRI standard. The method of claim 13, wherein the synchronization signal, And a system reference clock or a TDD synchronization signal that varies according to the channel bandwidth information. A separate base station comprising a digital unit and a remote RF unit, A remote RF unit for providing the digital unit with channel bandwidth information being used in the remote RF unit among a plurality of channel bandwidths available in the remote RF unit performing the RF processing of the detached base station; And Confirm the received channel bandwidth information, generate a synchronization signal by adjusting an oscillation frequency corresponding to the identified channel bandwidth information, and use the synchronization signal in a transmission / reception operation environment corresponding to the confirmed channel bandwidth information. A digital unit for controlling a transmission / reception operation so that modulation and demodulation processing of the IQ signal of the separate base station is performed; Detachable base station comprising a. The method of claim 22, wherein the digital unit, Generate a clock based on the synchronization signal according to the identified channel bandwidth information, and perform the modulation and demodulation process according to the transmission and reception operation environment setting determined by the confirmed channel bandwidth information and the timing determined by the clock. Separate base station, characterized in that for controlling the receiving operation.

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