KR100697209B1 - Synchronizing of the tdd wireless repeater - Google Patents

Abstract

The present invention relates to a synchronous control apparatus for a time division wireless repeater, and more particularly, to a synchronous control apparatus of the present invention, an RF repeater for transmitting or receiving an RF signal, a first switch switched to transmit and receive an RF signal in the RF repeater, and Detects the downlink or uplink signal with the second switches and calculates the guard signal of the Transmit Transition Gap (TGT) or the Receive Transition Gap (RTG) to the downlink or uplink direction depending on the downlink or uplink end point. And a synchronization control unit for generating a switch control signal for synchronously switching the first and second switches to transmit the RF signal. Therefore, the present invention implements a synchronous control device that detects downlink or uplink signals through detectors and comparators, calculates TTG / RTG guard signals, and generates switch control signals for wireless repeaters, so that the downlink or uplink even with low-cost components. The motivation can be secured accurately.

Time Division Wireless Repeater, Synchronous Control, Switch, Uplink, Downlink

Description

Synchronous control device of time division wireless repeater {SYNCHRONIZING OF THE TDD WIRELESS REPEATER}

1A and 1B are views illustrating an RF repeater and an optical repeater, respectively, of a typical wireless repeater;

2 is a circuit diagram illustrating a time division RF repeater according to the prior art;

3 is a circuit diagram showing a time-division optical repeater according to the prior art;

4 is a diagram illustrating a synchronization control device used in a time division wireless repeater according to the prior art;

5 is a circuit diagram illustrating a time division RF repeater having a synchronous control device according to an embodiment of the present invention;

6 is a diagram illustrating a frame structure of a time division signal;

7 illustrates a synchronization control device used for a time division wireless repeater according to the present invention;

8 is a circuit diagram illustrating a time division optical repeater having a synchronous control device according to another embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

140: synchronization control unit 140a: down / uplink signal detection circuit

140b: MICOM 140c: FPGA

1400: Amplifier 1402: Detector

1404: comparator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless repeater, and more particularly, to synchronous control in a time division wireless repeater capable of securing synchronization of an uplink or downlink signal transmitted between a base station and a terminal in a time division duplex (TDD) type wireless repeater. Relates to a device.

At present, the service users are gradually increasing with the development of wireless communication systems such as mobile phones. Since the wireless base station is expensive, a repeater for amplifying and transmitting a signal between the wireless base station and the wireless terminal is mainly installed in a low traffic area.

The repeater used in such a wireless communication system uses the same frequency channel for uplink (uplink) toward the wireless base station in the wireless terminal and downlink channel signals for the wireless terminal in the wireless base station, and time-divisions them. The downlink channel signal and the uplink channel signal are transmitted in a (TDD) manner. That is, in this time division (TDD) wireless repeater, the downlink and uplink channel signals have the same frequency, whereas the transmission time is separated. Such a time division wireless repeater is largely classified into an RF repeater and an optical repeater.

1A and 1B are diagrams illustrating an RF repeater and an optical repeater, respectively, of a general wireless repeater. Referring to FIG. 1A, the RF repeater 20 receives an RF signal sent from a wireless base station (BTS) 10 during downlink and amplifies the RF signal, for example, a wireless terminal (eg, a mobile communication terminal, a wireless notebook, etc.) 30. In the uplink, an RF signal transmitted from the wireless terminal 30 is received and amplified and transmitted to the wireless base station (BTS) 10. In this case, reference numerals 12, 22, and 24 described herein refer to antennas.

Referring to FIG. 1B, the optical repeater 50 is divided into a master repeater 52 and a slave repeater 56, and the master repeater 52 is located in the wireless base station (BTS) 40 and the slave repeater 56. Is located in the service area and these master repeaters 52 and slave repeaters 56 are connected by an optical fiber 54. The optical repeater 50 receives the optical signal of the wireless base station (BTS) 40 from the master repeater 52 in the downlink, amplifies it, and then transmits the optical signal to the slave repeater 56 through the optical fiber 54. The slave repeater 56 amplifies the optical signal transmitted to the wireless terminal 60 and transmits it to the wireless terminal 60 as an optical signal. In the uplink, the slave repeater 56 receives the optical signal of the wireless terminal 60, amplifies it, transmits the optical signal to the master repeater 52 through the optical fiber 54, and transmits the corresponding optical signal from the master repeater 52. Transmit to wireless base station (BTS) 40. In this case, reference numerals 42, 58, and 24 denote antennas.

2 is a circuit diagram illustrating a time-division RF repeater according to the prior art, in which a conventional RF repeater 20 includes antennas 22 and 24, filters 200 and 222, couplers 202 and 222, First switch 204, first low noise amplifier (LNA) 206, downlink control module 208, first high power amplifier (HPA) 210, second LNA 212, uplink control Module 214, a second HPA 216, and a second switch 218. In this case, the filters 200 and 22 are formed of a band pass filter (BPF).

The time-dividing RF repeater configured as described above transmits the RF signal received from the wireless base station through the antenna 22 to the coupler 202 through the bandpass filter 200 during the downlink, and switches in the downlink direction. The switch 204 transmits to the first LNA 206, the downlink control module 208, and the first HPA 210. The second switch 218, which is switched in the downlink direction, is transmitted to the antenna 24 through the coupler 220 and the band pass filter 222. The RF signal transmitted through the antenna 24 is transmitted to a wireless terminal (for example, a mobile communication terminal, a wireless notebook, etc.).

On the contrary, during the uplink, the RF signal received from the wireless terminal through the antenna 24 is transmitted to the coupler 220 through the bandpass filter 222 and through the second switch 218 switched in the uplink direction. It transfers to the second LNA 218, the uplink control module 214, and the second HPA 216. The RF signal transmitted through the antenna 24 is transmitted to the wireless base station through the first switch 204, the coupler 202, and the bandpass filter 200 which are switched in the uplink direction. do.

FIG. 3 is a circuit diagram showing a time-division optical repeater according to the prior art, and the conventional optical repeater includes antennas 42 and 58, optical transmitters 52 and 56, and an optical path 54. As shown in FIG. Here, the downlink-side optical transmitter 52 may include a band pass filter 230, a coupler 232, a first switch 234, a first LNA 236, and a first E / O for converting an electrical signal into an optical signal. Electrical / Optical conversion optical module 238, Wavelength Division Multiplexing (WDM) 240, first optical / electrical conversion optical module 242 for converting optical signals to electrical signals, first HPA 244 It consists of. The uplink side optical transmitter 56 includes a WDM 246, a second O / E conversion optical module 248, a coupler 250, a second HPA 252, a second LNA 254, and a second E / O conversion optical. Module 256, second switch 258, and bandpass filter 260.

The time division type optical repeater configured as described above also transmits optical signals in the downlink and uplink directions as described above.

The time-division RF repeater or optical repeater according to the prior art uses the same frequency for downlink and uplink, and thus repeatedly transmits (downlinks) and receives (uplinks) for a predetermined time based on time. At this time, the first and second switches in each repeater further include a synchronization controller 26 because synchronization is required for each other in a downlink or uplink direction.

4 is a diagram illustrating a synchronous control apparatus used for a time division wireless repeater according to the prior art, wherein the synchronization control unit 26 of the conventional time division wireless repeater includes a local oscillator 26a oscillating with a constant frequency signal, and When the RF signal of the link is transmitted through the coupler, the mixer 26b mixes the signal of the local oscillator 26a and down-converts the baseband, and converts the baseband signal of the mixer 26b into a digital signal. The first switch or the second switch which is switched in the down or uplink direction in the repeater by extracting the OFDM pilot symbols related to the synchronization from the time division frame information through the demodulation process of the ADC 26c and the digital signal converted by the ADC 26c. Field Programmable Gate Array (FPGA) 26e for generating a switch control signal for driving the switch. Here, the FPGA 26e controls the data DATA, the address ADDRESS, the read RD, the write WR, and the like from the MICOM 26d, and the unexplained OCXO represents a clock signal. .

Although not shown in detail in the figure, the FPGA 26e includes a block synchronization module such as an FFT block, demodulation blocks such as FFT blocks, QPSK, 16 QAM, and 64 QAM, and a frame protocol such as a demodulated SICH. It is composed of blocks that generate the switch control signal by analyzing the TTG and RTG timing. The FPGA 26e switches a first switch or a second switch by providing a wireless control switch with a switch control signal that is activated on in the TTG and RTG intervals to switch downlink or uplink.

Therefore, the conventional synchronization control device in a time division wireless repeater (RF / optical repeater) couples the signal input to the repeater to convert it into a baseband and performs an OFDM pilot related to synchronization among time division frame information demodulated through the ADC and the FPGA. The symbol is extracted to generate a switch control signal of the first switch or the second switch which is switched in the down or uplink direction in the repeater.

However, the conventional synchronous control apparatus uses expensive components of a local oscillator, a mixer, and an ADC, and has a disadvantage in that it is incompatible with a time division wireless communication service having a different frame structure such as another time division repeater, for example, CDMA.

Therefore, unlike the base station equipment, there was a limit in using an expensive synchronization control device in a wireless repeater with a large quantity and a relatively low price.

An object of the present invention is to detect the downlink or uplink signal to calculate the guard signal of the Transmit Transition Gap (RTG) or Receive Transition Gap (RTG) in order to solve the above problems of the prior art switch control signal of the wireless repeater The present invention provides a synchronization control device in a time division wireless repeater capable of accurately securing downlink or uplink even by inexpensive components by implementing a synchronization control device for generating a C.

In order to achieve the above object, the present invention provides a time-division wireless repeater comprising: an RF repeater for transmitting or receiving an RF signal, first and second switches switched for transmitting and receiving an RF signal in the RF repeater, and receiving To detect the downlink or uplink signal of the detected RF signal, calculate the guard signal of the TTG or RTG in the detected signal, and transmit the RF signal in the downlink or uplink direction according to the downlink or uplink end point. A synchronous controller for generating a switch control signal for synchronously switching the first and second switches, the synchronous controller comprising a down / uplink signal detection circuit for detecting a downlink or uplink signal of a received RF signal; Calculates the guard signal of the TTG or RTG in the detected signal according to the output level of the uplink signal detection circuit and drives the first and second switches synchronously And a FPGA for generating a switch control signal group.

In order to achieve the above object, another apparatus of the present invention is a time division wireless repeater comprising: an optical repeater for transmitting or receiving an optical signal, and first and second switches switched to transmit and receive an optical signal in the optical repeater; Detects the downlink or uplink signal in the received optical signal, calculates the guard signal of the TTG or RTG in the detected signal, and transmits the optical signal in the downlink or uplink direction according to the downlink or uplink end point; And a synchronization controller for generating a switch control signal for synchronously switching the first and second switches, wherein the synchronization controller detects a downlink or uplink signal of the received optical signal. And a first and second switch by calculating a guard signal of TTG or RTG in the detected signal according to the output level of the down / uplink signal detection circuit. Synchronously it includes FPGA for generating a switch control signal for the driving.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

5 is a circuit diagram illustrating a time division RF repeater having a synchronous control device according to an embodiment of the present invention.

Referring to FIG. 5, the time division RF repeater 100 according to an embodiment of the present invention includes antennas 130 and 132, band pass filters 102 and 124, couplers 104 and 122, and a first switch. 106, the first LNA 108, the downlink control module 110, the first HPA 112, the second LNA 114, the uplink control module 116, the second HPA 118, The second switch 120 and the synchronization controller 140 are included.

The time-dividing RF repeater configured as described above transmits the RF signal received from the wireless base station through the antenna 130 to the coupler 102 through the bandpass filter 102 in the downlink, and the synchronization controller 140 of the present invention. It is transmitted to the first LNA 108, the downlink control module 110, and the first HPA 112 through the first switch 106 is switched in the downlink direction by the switch control signal of. The second switch 120, the coupler 122, and the band pass filter 124, which are switched in the uplink direction by the switch control signal of the synchronization controller 140, are transferred to the antenna 132. The RF signal transmitted through the antenna 132 is transmitted to a wireless terminal (for example, a mobile communication terminal, a wireless notebook, etc.).

On the contrary, during the uplink, the RF signal received from the wireless terminal through the antenna 132 is transmitted to the coupler 122 through the band pass filter 124, and the uplink direction is controlled by the switch control signal of the synchronization controller 140. The second switch 120 is switched to the second LNA 114, the uplink control module 116, and the second HPA 118. The first switch 106 and the coupler 1042 and the band pass filter 102 which are switched in the uplink direction by the switch control signal of the synchronization control unit 140 are transmitted to the antenna 130 and the antenna 130. The RF signal transmitted through is transmitted to the wireless base station.

FIG. 6 illustrates a frame structure of a time division signal, in which one frame of the time division (TDD) signal is divided into a downlink and an uplink, and a guard signal called a transmit transition gap (TGT) exists between the downlink and the uplink. After the uplink signal, there is a guard signal called a receive transition gap (RTG).

7 is a diagram illustrating a synchronization control device used for a time division wireless repeater according to the present invention. Referring to FIG. 7, the synchronization controller 140 in the time division wireless repeater (RF / optical repeater) according to the present invention includes a down / uplink signal detection circuit 140a, a MICOM 140b, and an FPGA 140c. ).

Here, the down / uplink signal detection circuit 140a is coupled to the amplifier 1400 through a coupler to amplify the input signal, and a detector 1402 to detect a downlink or uplink signal level from the amplified signal. And a comparator 1404 for amplifying the difference between the detected level and the reference signal.

The microcomputer 140b transmits data DATA, address ADDRESS, read RD, write WR, ALE, etc. of the FPGA 140c and controls the operation of the FPGA 140c.

The FPGA 140c of the present invention calculates the guard signal of the TTG or RTG in the detected signal according to the output level of the down / uplink signal detection circuit 140a to determine the downlink or uplink end point and determines the downlink or uplink. A switch control signal for synchronously driving the first or second switch of the wireless repeater is generated according to the link direction. Unexplained OCXO represents a reference clock signal.

More specifically, the synchronization control unit 140, which is a synchronization control device applied to a time division RF repeater according to an embodiment of the present invention, operates as follows.

A parameter (period, TTG, or RTG) of one time-division frame is set through the microcomputer 140b and provided to the FPGA 140c.

The FPGA 140c counts down the clock signal, OCXO, when the signal output from the down / uplink signal detection circuit 140a is at the set level (for example, 1) of the downlink, and then the down / uplink signal detection circuit 140a. It is determined whether the signal output from the second level is a different level (for example, 2). If the signal output from the down / uplink signal detection circuit 140a is a signal of a different level (for example, 2), the counted OCXO clock signal is compared with the value of the downlink, and if these values are the same, the preset TTG Time is calculated and a switch control signal is generated for synchronizing and switching the first and second switches 106, 120 in the downlink direction until the TTG guard time.

In addition, when the signal output from the down / uplink signal detection circuit 140a is a set level (for example, 3) of the uplink, the FPGA 140c counts a clock signal, which is an OCXO, and then the down / uplink signal detection circuit. It is determined whether the signal output at 140a is another level (for example, 4). If the signal output from the down / uplink signal detection circuit 140a is a signal of a different level (for example, 4), the counted OCXO clock signal is compared with the value of the uplink, and if these values are the same, the preset RTG Compute information and generate a switch control signal for driving the first and second switches 106, 120 in the uplink direction until RTG guard time.

8 is a circuit diagram illustrating a time division optical repeater having a synchronous control device according to another embodiment of the present invention. The time division optical repeater 300 according to another embodiment of the present invention includes antennas 340 and 342, The transmitters 310 and 330, the optical path 320, and the synchronization controller 350 are included.

Here, the downlink side optical transmitter 310 includes a band pass filter 311, a coupler 312, a first switch 314, a first LNA 315, a first E / O conversion optical module 316, and a WDM ( 317, a first O / E conversion optical module 318, and a first HPA 319.

The uplink side optical transmitter 330 may include a WDM 331, a second O / E conversion optical module 332, a coupler 333, a second HPA 338, a second LNA 334, and a second E / O conversion light. Module 335, second switch 336, and bandpass filter 337.

The synchronization controller 350, which is a synchronization control device applied to a time division optical repeater according to another embodiment of the present invention configured as described above, has the same configuration as the synchronization controller described above with reference to FIG. 7 and operates as follows.

First, a parameter (period, TTG, or RTG) of one time-division frame is set through the microcomputer 140b and provided to the FPGA 140c.

The FPGA 140c counts down the clock signal, OCXO, when the signal output from the down / uplink signal detection circuit 140a is at the set level (for example, 1) of the downlink, and then the down / uplink signal detection circuit 140a. It is determined whether the signal output from the second level is a different level (for example, 2). If the signal output from the down / uplink signal detection circuit 140a is a signal of a different level (for example, 2), the counted OCXO clock signal is compared with the value of the downlink, and if these values are the same, the preset TTG The switch calculates time and generates a switch control signal for synchronizing and switching the first and second switches 314 and 336 of the optical transmitters 310 and 330 in the downlink direction until the TTG guard time.

In addition, when the signal output from the down / uplink signal detection circuit 140a is a set level (for example, 3) of the uplink, the FPGA 140c counts a clock signal, which is an OCXO, and then the down / uplink signal detection circuit. It is determined whether the signal output at 140a is another level (for example, 4). If the signal output from the down / uplink signal detection circuit 140a is a signal of a different level (for example, 4), the counted OCXO clock signal is compared with the value of the uplink, and if these values are the same, the preset RTG The switch calculates information and generates a switch control signal for driving the first and second switches 314 and 336 of the optical transmitters 310 and 330 in the uplink direction until the RTG guard time.

As described above, the present invention provides a low-cost component by implementing a synchronous control device that detects the downlink or uplink through a detector and a comparator and calculates a TTG / RTG guard signal from the detected signal to generate a switch control signal of a wireless repeater. Also, accurate synchronization of downlink or uplink can be achieved.

In addition, the synchronous control apparatus in the time division wireless repeater (RF / optical repeater) of the present invention uses a downlink or uplink guard signal to synchronize the transmit / receive switch without extracting an OFDM pilot symbol. It is possible to be compatible with a wireless communication service such as a repeater, for example, CDMA.

On the other hand, the present invention is not limited to the above-described embodiment, various modifications are possible by those skilled in the art within the spirit and scope of the present invention described in the claims to be described later.

Claims (6)

delete In time division wireless repeater, An RF repeater for transmitting or receiving an RF signal, First and second switches switched to transmit and receive the RF signal in the RF repeater; Detecting a downlink or uplink signal of the received RF signal, and calculating a guard signal of a transmit transition gap (RTG) or a receive transition gap (RTG) in the detected signal, according to the downlink or uplink end point. A synchronous control unit for generating a switch control signal for synchronously switching the first and second switches to transmit the RF signal in a downlink or uplink direction Including; The synchronization control unit, A down / uplink signal detection circuit for detecting a downlink or uplink signal of the received RF signal and a guard signal of a TTG or RTG in the detected signal according to an output level of the down / uplink signal detecting circuit; An FPGA for generating a switch control signal for synchronously driving the first and second switches Synchronous control device of a time division wireless repeater comprising a. 3. The apparatus of claim 2, wherein the down / uplink signal detection circuit comprises: an amplifier for amplifying a coupled signal of the received RF signal, a detector for detecting a downlink or uplink signal level from the amplified signal, and And a comparator for amplifying the difference between the detected level and the reference signal. delete In time division wireless repeater, An optical repeater for transmitting or receiving an optical signal, First and second switches switched to transmit and receive the optical signal in the optical repeater; Detects a downlink or uplink signal in the received optical signal, calculates a guard signal of a transmit transition gap (RTG) or a receive transition gap (RTG) in the detected signal, according to the downlink or uplink termination point; A synchronous control section for generating a switch control signal for synchronously switching the first and second switches to transmit the optical signal in a downlink or uplink direction Including; The synchronization control unit, A down / uplink signal detection circuit for detecting a downlink or uplink signal of the received optical signal and a guard signal of a TTG or RTG in the detected signal according to an output level of the down / uplink signal detecting circuit; An FPGA for generating a switch control signal for synchronously driving the first and second switches Synchronous control device of a time division wireless repeater comprising a. 6. The apparatus of claim 5, wherein the down / uplink signal detection circuit comprises: an amplifier for amplifying a coupled signal of the received optical signal, a detector for detecting a downlink or uplink signal level from the amplified signal, And a comparator for amplifying the difference between the detected level and the reference signal.

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