KR20010044649A - Apparatus and method for automatic control of receiver gain of optic repeater - Google Patents

Abstract

PURPOSE: An apparatus and a method for automatically controlling a receiving gain of an optical repeater are provided to remotely monitor and control a gain of a receiving part of an optical repeater to improve a performance an optical repeater system by automatically measuring the gain of the receiving part of the optical repeater according to an instruction of a base station and adjusting a variable attenuator to automatically controlling the gain of the receiving part to a suitable level. CONSTITUTION: A remote unit and a doner unit communicate to each other through a modem communication(S10). A reference frequency generator of the remote unit is driven by a control signal transmitted to a base station during the modem communication, to generate a reference frequency(S20). The reference frequency generated from the reference frequency generator is coupled with a receiving signal and a diversity signal by the second and the third coupler and transmitted to the doner unit(S30,S40). The reference frequency is separated by the second and the third separators at the terminal of a receiving part of the doner unit(S50). The level of the separated reference frequency is detected by the first and the second level detectors(S60). The level of the reference frequency detected by the first and the second level detectors is compared with the level of the reference frequency generated from the remote unit to measure the whole gain of the receiving path of the receiving signal and the receiving path of the diversity signal(S70). After the whole gain of the receiving path is measured, the first and the second variable attenuators of the doner unit are controlled to constantly maintain a receiving gain of the overall receiving signal and the diversity signal of the optical repeater(S80).

Description

Apparatus and method for automatic control of receiver gain of optic repeater}

The present invention relates to an automatic gain control device and a method of receiving an optical repeater, and more particularly, by receiving a reference frequency generated by the remote part of the optical repeater at the donor part along the receiving path and measuring the magnitude of the reference frequency. An apparatus and method for automatically adjusting a reception gain of an optical repeater to measure the reception gain of the entire receiver based on the optical repeater and automatically adjust the gain of the entire receiver appropriately according to a control signal of the base station.

With the development of mobile communication, the number of users is increasing rapidly, and the base station has the greatest impact on the economics and service quality of the system due to its large number and high cost in order to meet the usage patterns and various demands.

In building a mobile communication network, it is preferable to cover all service areas with general base stations, but in actual network configuration, base stations are arranged in consideration of economic efficiency, so underground spaces and apartment complexes, which are blind spots of radio waves among mountain walls, remote islands, and urban areas In large buildings, hills, underground, etc., there are many unserviceable areas where radio waves cannot reach.

In particular, in terms of communication traffic, about 85% of the communication traffic is concentrated in 5% of the total area for providing a mobile communication service, and only about 15% of traffic is generated in the remaining 95% of the area. Therefore, in order to provide high quality telecommunication services at low cost for major areas such as highways, national highways and open areas where traffic is low but coverage is important, it is more efficient to use repeaters instead of base stations, which are expensive to install and maintain. to be.

1 is an exemplary view of using an optical repeater of a general mobile communication system.

As shown here, by installing the optical repeater 20 between the service area and the non-service area by the base station 10 to transmit the RF radio waves through the optical path 30, the service area by the base station 10 Serviced, the out of service area is serviced by the optical repeater 20.

The donor unit 21 is connected to the base station 10 and transmits the signal of the terminal 25 transmitted in the service area and the information about the remote unit 22 transmitted by the modem of the remote unit 22 to the base station 10. The base station 10 transmits a signal transmitted from the base station 10 to the terminal 25 and a signal controlling the remote unit 22 from the base station 10.

The remote unit 22 transmits the signal of the terminal 25 in the service area and the status information of the remote unit 22 to the donor unit 21, and transmits the signal transmitted from the donor unit 21 to the service area. The control unit 25 transmits the control signals transmitted from the donor unit 21 to the terminal 25 and controls the remote unit 22 itself.

Such an optical repeater can measure the magnitude of the output at the final stage of the transmitter and adjust the internal attenuator to adjust the gain of the entire system to output the desired output signal. This is possible because the magnitude of the input signal and the magnitude of the output signal are known.

However, since the receiver does not know the magnitude of the input signal accurately, it is inevitable to measure the receiver input with a measuring instrument to know the receiver gain during the installation and operation of the optical repeater.

At this time, the received signal input to the optical repeater is combined with the signal of the base station through the receiving path of the optical repeater, initially set to be somewhat lower than the received signal of the base station so that the signal of the repeater does not affect the base station.

However, if the receiver gain of the entire optical repeater increases due to changes in the optical line, transmission line, or elements of the optical repeater during operation, the call quality of the optical repeater itself is degraded if the receiver gain decreases. Receiver gain is a very important parameter for operating an optical repeater.

2 is a block diagram schematically illustrating a receiver of a general optical repeater.

As shown here, the diversity signal RX1 received at the diversity antenna 40 of the remote unit 22 is the diversity oscillation frequency LO and the first mixer 50 transmitted from the donor unit 21. Mixed with the down-converted signal and then received by the receiving signal RX0 received from the receiving antenna 42 and the first combiner 60, are converted into an optical signal through the all-optical conversion module 70, and then via the optical path 30 Is sent to the donor section 21.

Then, the donor unit 21 converts the optical signal transmitted from the remote unit 22 into an electrical signal through the photoelectric conversion module 72 and then receives the received signal RX0 and the diversity signal through the first separator 90. Remove (RX1).

Then, the separated reception signal RX0 is transmitted to the base station 10 after band filtration and amplification, and the diversity signal RX1 is mixed at the diversity oscillation frequency LO and the second mixer 52 and thus the original signal. It is restored to and transmitted to the base station 10 after the band filtering and amplification.

In this case, when the first to second variable attenuators 100 and 102 of the donor unit 21 are adjusted, the gain of the receiver by adjusting the gains of the entire reception signal RX0 and the diversity signal RX1 of the optical repeater 20 is adjusted. It can be kept constant.

Then, the modem 80 transmits the status information of the remote unit 22 to the base station 10 and transmits a control signal CONTROL of the base station 10 so as to control itself.

However, since the input levels of the reception signal RX0 and the diversity signal RX1 received from the remote unit 22 are not known in the above path, the reception signal RX0 and the diversity signal of the donor unit 21 are not known. The reception gain for RX1) is unknown.

Therefore, in order to know the reception gain, not only when the optical repeater 20 is installed, but also when the optical repeater 20 is operated, a person directly measures the gain of the receiving end of the base station donor unit 21 by using a measuring instrument. The reception input level of the remote section 22 of the optical repeater 20 must be measured.

However, in general, since the remote unit 22 of the optical repeater 20 is installed on a pole or a steel tower, there is a problem that a human is involved in a dangerous operation to measure an input level of a receiver using a measuring instrument.

In addition, since a person must directly measure the input level of the receiver using a measuring instrument, there is a problem in that the receiver gain of the optical repeater cannot be automatically adjusted.

The present invention has been made to solve the above problems, an object of the present invention is to automatically measure the receiver gain of the optical repeater according to the instructions of the base station, by adjusting the variable attenuator to automatically adjust the receiver gain to an appropriate level An apparatus and method for automatically adjusting a reception gain of an optical repeater for enabling a base station to remotely monitor and control a receiver gain of an optical repeater.

1 is an exemplary view of using an optical repeater of a general mobile communication system.

2 is a block diagram schematically illustrating a receiver of a general optical repeater.

3 is a block diagram schematically illustrating a receiver of an optical repeater according to the present invention.

4 is a flowchart illustrating a method for automatically adjusting a reception gain of an optical repeater according to the present invention.

-Explanation of symbols for the main parts of the drawings-

10: base station 20: optical repeater

21: donor portion 22: remote portion

30: optical path 40: diversity antenna

42: reception antenna 50, 52: first to second mixer

60, 62, 64: first to third combiners

70: photoelectric conversion module 72: photoelectric conversion module

80: modem 90,92,94: first to third separator

100,102: first to second variable attenuator

110: reference frequency generator 120,122: first to second level detector

Receiving automatic control device of the optical repeater according to the present invention for realizing the above object is to combine the received signal and the diversity signal received from the antenna of the remote unit to convert the optical signal by the all-optical conversion module through the optical path An optical repeater configured to convert an optical signal transmitted to a donor part through a photoelectric conversion module to separate a received signal and a diversity signal, and to adjust a reception gain through a variable attenuator and transmit the received signal to a base station. A reference frequency generator for generating a reference signal for measuring reception gain by means of the first frequency generator, a first combiner for coupling the output signal of the reference frequency generator with the diversity signals received from the antennas, The output signal of the reference frequency generator and the received signal received from the antenna A second combiner to be combined, a first separator installed at the donor section to separate the reference frequency from the separated diversity signal, a first level measurer measuring the level of the reference frequency separated from the first separator, and a donor section And a second separator for separating the reference frequency from the separated received signal, a second level measuring device for measuring the level of the reference frequency separated from the second separator, and a base station according to the reception gain measured by the output value of the first level measuring device. A first variable attenuator in which the reception gain of the diversity signal is adjusted by a control signal of the second signal, and a second in which the reception gain of the reception signal is adjusted by a control signal of the base station according to the reception gain measured by the output value of the second level measuring instrument. It further comprises a variable attenuator.

The frequency generated by the reference frequency generator is characterized by using the frequency between the FA and FA so as not to interfere with the service of the base station reception band in use.

In addition, the method of automatically adjusting the reception gain of the optical repeater according to the present invention comprises the steps of performing modem communication between the remote unit and the donor unit, generating a reference frequency through the reference frequency generator of the remote unit by a control signal transmitted to the base station; And combining the generated reference frequency with the reception signal and the diversity signal to the donor unit, separating the reference frequency transmitted from the remote unit through a separator at the receiving end of the donor unit, and measuring the level of the separated reference frequency. And measuring the reception gain of the receiver using the measured reference frequency and the level of the reference frequency generated by the remote unit, and adjusting the variable attenuator according to the measured reception gain to automatically adjust the receiver gain of the repeater. Characterized in that the step consisting of adjusting.

The present invention made as described above generates a reference frequency for measuring the reception gain, the level of which can be known by the control signal of the base station in the remote unit, and receives the received signal from the donor unit by combining the reference frequency and the reception signal and the diversity signal. By measuring the level by separating the reference frequency, it is possible to measure the reception gain in the reception path, so that the reception gain can be automatically adjusted uniformly even if the remote unit does not directly measure the measurement.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the present embodiment is not intended to limit the scope of the present invention, but is presented by way of example only and the same parts as in the conventional configuration using the same reference numerals and names.

3 is a block diagram schematically illustrating a receiver of an optical repeater according to the present invention.

As shown here, the remote unit 22 of the optical repeater 20 is provided with a reference frequency generator 110 by a PLL element for generating a reference frequency for receiving gain measurement under the control of the base station 10.

In this case, the reference frequency generated by the reference frequency generator 110 uses a frequency between the FA and the FA so that service does not interfere with the base station reception band in use.

In addition, the remote unit 22 includes a second combiner 62 for coupling the output signal of the reference frequency generator 110 with the diversity signal RX1 received through the diversity antenna 40 and the reference frequency generator 110. A third combiner 64 is provided which couples the output signal of the < RTI ID = 0.0 >) < / RTI >

In addition, a first mixer 50 for down-converting by mixing the output signal of the second combiner 62 and the diversity oscillation frequency LO transmitted from the donor unit 21 is provided.

The first combiner 60 and the first combiner 60 which combine the diversity signal RX1 which is the output signal of the first mixer 50 and the reception signal RX0 which is the output signal of the third combiner 64. An all-optical conversion module 70 for converting an output signal of the optical signal into an optical signal is provided.

In addition, the donor part 21 is provided with a photoelectric conversion module 72 for converting the optical signal transmitted through the optical path 30 to an electrical signal, and diversity in the electrical signal converted by the photoelectric conversion module 72 A first separator 90 for separating the signal RX1 and the received signal RX0 is provided.

Then, a second mixer 52 is installed, which is mixed with the diversity signal RX1 and the diversity oscillation frequency LO separated by the first separator 90 and restored to the original signal.

In addition, the second separator 92 that separates the reference frequency from the diversity signal RX1 restored in the second mixer 52 and the first level that measures the level of the reference frequency separated by the second separator 92 Meter 120 is installed.

In addition, the third separator 94 for separating the reference frequency from the received signal (RX0) separated in the first separator 90, and the second level meter for measuring the level of the reference frequency separated in the third separator 94 122 is installed.

Then, the first variable attenuator 100 whose reception gain of the diversity signal is adjusted by the control signal CONTROL of the base station according to the reception gain measured by the output value of the first level measuring unit 120 is the diversity signal RX1. A second variable attenuator (102) installed at a receiving end and adjusting the received gain of the received signal by a control signal (CONTROL) of the base station 10 according to the received gain measured by the output value of the second level measuring instrument 122. Is installed at the receiving end of the receiving signal RX0.

Optical repeater 20 according to the present invention made as described above generates a reference frequency for measuring the reception gain in the reference frequency generator 110 of the remote unit 22. The reference frequency, which is an output signal of the reference frequency generator 110, is applied to the reception paths of the reception signal RX0 and the diversity signal RX1 by the second combiner 62 and the third combiner 64 to be combined. And it is converted into an optical signal through the all-optical conversion module 70 is transmitted to the donor unit 21 through the optical path (30).

Then, the donor part 21 converts the output optical signal of the remote part 22 input through the optical path 30 through the photoelectric conversion module 72 into an electric signal and then receives the signal by the first separator 90. The signal RX0 and the diversity signal RX1 are separated.

Then, in the case of the received signal after performing the band filtering and amplification to pass a constant frequency, the received signal (RX0) and the reference frequency is separated through the third separator 94 in the final stage.

The diversity signal RX1 is mixed in the diversity oscillation frequency LO and the second mixer 52, restored to the original signal, and then subjected to band filtering and amplification through a predetermined frequency. The diversity signal RX1 and the reference frequency are separated through the second separator 92.

In this way, the reference frequency separated by the second separator 92 and the third separator 94 is measured at the first level detector 120 and the second level detector 122.

The reception of the optical repeater 20 by measuring the level of the reference frequency detected at the end of the receiving path of the donor unit 12 while the level of the reference frequency applied to the reception path is recognized by the remote unit 22 as described above. Receiving gain of the optical repeater 20 by the first to second variable attenuator 100) 102 operated by the base station 10 control signal CONTROL to keep the reception gain constant as the gain is measured. Will be adjusted automatically.

Then, the modem 80 transmits the state information of the remote unit 22 to the base station 10 and transmits a control signal CONTROL of the base station 10 to control itself.

Referring to the flowchart for explaining the automatic reception gain adjustment method of the optical repeater according to the present invention shown in Figure 4 the automatic reception gain adjustment method of the optical repeater operated as described above is as follows. .

First, the modem unit communicates with each other by using modem communication between the remote unit 22 and the donor unit 21.

As described above, the reference frequency generator 110 of the remote unit 22 is driven by the control signal CONTROL transmitted to the base station 10 during the modem communication to generate the reference frequency.

In this case, the reference frequency generated by the reference frequency generator 110 uses a frequency between the FA and the FA so that service does not interfere with the reception band of the base station 10 in use.

The reference frequency generated by the reference frequency generator 110 is coupled to the reception signal RX0 and the diversity signal RX1 by the second to third combiners 62 and 64 and transmitted to the donor part 21.

Then, the reference frequency is separated by the second to third separators 92 and 94 at the receiver end of the donor portion 21.

Then, the levels of the separated reference frequencies are detected by the first to second level detectors 120 and 122.

The reception path and the diversity signal of the reception signal RX0 are compared with the level of the reference frequency generated by the remote unit 22 based on the level of the reference frequency detected by the first to second level detectors 120 and 122. The overall gain of the reception path of (RX1) is measured.

After measuring the overall gain of the reception path as described above, the first to second variable attenuators 100 and 102 of the donor part 21 are adjusted to receive the entire received signal RX0 and the diversity signal RX1 of the optical repeater 20. Keep the reception gain constant)

As described above, the present invention measures the gain of the entire receiver by measuring the magnitude of the reference frequency by receiving the reference frequency generated by the remote part of the optical repeater at the donor along the receiving path and measuring the magnitude of the reference frequency. By automatically adjusting the constant, the user can improve the performance of the optical repeater system by remotely monitoring and controlling the receiver gain of the optical repeater at the base station without measuring the input of the receiver with a measuring instrument on a pole or pylon equipped with the remote part directly. have.

In addition, since the receiver input can be automatically measured at the base station, there is an advantage that a human can reduce the risk and troublesome measurement.

Claims (7)

The reception signal and the diversity signal received from the antennas of the remote unit are combined and converted into an optical signal by the all-optical conversion module. The optical signal transmitted to the donor part through the optical path is converted by the photoelectric conversion module to convert the received signal and the diversity signal. In the receiving unit of the optical repeater configured to transmit to the base station by adjusting the reception gain through the variable attenuator, A reference frequency generator installed at the remote unit and generating a reference frequency for receiving gain measurement under control of a base station; A combiner installed at the remote unit to combine the output signals of the reference frequency generator with the signals received from the antennas; A separator installed at the donor to separate a reference frequency from a received signal; A level meter for measuring the level of the reference frequency separated by the separator; Variable attenuator whose reception gain is adjusted by a control signal of the base station according to the reception gain measured by the output value of the level meter Receiving automatic adjustment device of an optical repeater, characterized in that further comprises a. The apparatus of claim 1, wherein the reference frequency generated by the reference frequency generator is a frequency between FA and FA which does not interfere with service among base station reception bands in use. The method of claim 1, wherein the coupler A first combiner installed at the remote unit to couple an output signal of a reference frequency generator with diversity signals received from the antennas; A second combiner installed in the remote unit to combine an output signal of a reference frequency generator with a received signal received from the antennas; Receiving automatic control device of the optical repeater, characterized in that consisting of. The method of claim 1, wherein the separator A first separator installed at the donor to separate the reference frequency from the divided diversity signal; A second separator installed at the donor to separate the reference frequency from the separated received signal; Receiving automatic control device of the optical repeater, characterized in that consisting of. The method of claim 1, wherein the level meter A first level measuring device measuring a level of the reference frequency coupled with the diversity signal separated by the separator; A second level measuring device for measuring the level of the reference frequency combined with the received signal separated by the separator; Receiving automatic control device of the optical repeater, characterized in that consisting of. The method of claim 1, wherein the variable attenuator A first variable attenuator in which the reception gain of the reception signal is adjusted by a control signal of the base station according to the reception gain in the reception path of the diversity signal measured by the output value of the level meter; A second variable attenuator in which the reception gain of the reception signal is adjusted by the control signal of the base station according to the reception gain in the reception path of the reception signal measured by the output value of the level meter. Receiving automatic control device of the optical repeater, characterized in that consisting of. Performing modem communication between the remote unit and the donor unit; Generating a reference frequency through the reference frequency generator of the remote unit by a control signal transmitted to a base station; Transmitting the generated reference frequency to the donor unit by combining the received frequency and the diversity signal; Separating the reference frequency transmitted from the remote unit through a separator at the receiving end of the donor unit; Measuring the level of the separated reference frequency; Measuring the reception gain of the receiver based on the level of the reference frequency measured above and the level of the reference frequency generated by the remote unit; Automatically adjusting the gain of the receiver of the optical repeater by adjusting the variable attenuator according to the measured reception gain. Receiving gain automatic adjustment method of the optical repeater, characterized in that consisting of.