KR100548425B1 - Method for diagnosing transmitting and receiving path of base station - Google Patents

Abstract

The present invention measures the code power of the forward signal radiated from the front-end of the base station to the antenna and the reverse signal reflected back from the antenna, and measures the temporal position of the frame boundary of the corresponding channel. The present invention relates to a transmission and reception path measuring apparatus and method of a base station capable of remotely diagnosing a transmission / reception path between antennas.

Path diagnosis, BTU, frame boundary, code power

Description

Device and method for diagnosing transmit and receive path of base station {METHOD FOR DIAGNOSING TRANSMITTING AND RECEIVING PATH OF BASE STATION}

1 is a view showing the structure of a conventional transmission path diagnostic apparatus of a base station.

2 is a view showing the structure of a conventional reception path diagnosis apparatus of a base station.

3 is a diagram showing the structure of a transmission path diagnosis apparatus of a base station according to the present invention;

4 is a time difference between frame boundaries of forward and reverse signals.

5 is a diagram showing the structure of a reception path diagnosis apparatus of a base station according to the present invention;

******* Explanation of symbols for the main parts of the drawing ********

13,22: Front-end 14,23: Lightning arrester

13a, 22a: Cable 100, 200: BTU

47: ULTD

The present invention relates to a path diagnosis of a base station, and more particularly, to an apparatus and method for diagnosing a transmission and reception path of a base station capable of remotely diagnosing an antenna matching condition and an antenna transmission / reception path.

In general, the diagnosis of the transmission paths generated from the various high frequency (RF) blocks in the base station enables the base station's modem operating environment to be operated more efficiently.

1 is a structure of a transmission path diagnosis apparatus of a base station.

As shown in FIG. 1, a conventional transmission path diagnosis apparatus includes a modem 10, a transceiver 11, a linear power amplifier (LPA) 12 and a front-end 13, and a cable 13a. , Arrester 14, and Base-station Test Unit (BTU 15).

First, the digital signal output from the modem 10 is up converted into an RF signal by the transceiver 11. The RF signal output from the transceiver 11 is amplified to a level high enough for the terminal to be received by the LPA 12 and then radiated to the antenna through the front-end 13, the cable 13a and the arrester 14. do.

At this time, the BTU 15 determines the failure of the transmission path by measuring the power of the RF signal transmitted from the base station. The voltage standing wave ratio (VSWR) of the antenna is determined based on the front-end 13. Measure the state of the antenna.

That is, the BTU 15 monitors the characteristics of the RF signal to diagnose the path from the modem 10 to the front-end 13, and measures the power of the forward and reverse paths based on the front-end 13. The state of the antenna is determined by measuring the voltage standing wave ratio VSWR of the antenna.

2 is a structure of a reception path diagnosis apparatus of a base station.

Referring to FIG. 2, the reception path diagnosis apparatus of the conventional base station includes an up / down converter 20, a power divider 21, a front-end 22, an arrester 23, and a BTU 24. It is composed.

The power divider 21 includes a 2-way device that separates the RF signal output from the front-end 22 into two paths, and a 6-way device that outputs one side output of the 2-way device to the up / down converter 20.

The front-end 22 includes a directional coupler, a duplexer and a low noise amplifier (LNA).

The BTU 24 is a single-tone generator 24a for generating a single tone signal, and forwards the single-tone signal under the control of a CPU (not shown). RF signal of the RF matrix 24b switching to the port and reverse port and the forward path through the forward port of the front-end 22 and the signal reflected from the antenna through the reverse port are measured. The power measurement unit 24c obtains a return loss of the antenna stage and a voltage standing wave ratio VSWR.

The single-tone signal output from the single-tone generator 24a of the BTU 24 is switched in the RF matrix 24b and input to the forward and reverse ports of the front-end 22.

The power measuring unit 24c of the BTU 24 measures the VSWR of the base station receiving antenna using the RF power of the signals passing through the LNA. In addition, the power measuring unit 24c diagnoses a reception path from the front-end 22 to the LNA using RSSI (Received Signal Strength Indication) of the signal output from the LNA, and the front-end 22 and the power divider. It is possible to diagnose a reception path from the LNA to the up / down converter 20 by using the RSSI of the signal reaching the up / hot converter 20 through 21.

Hereinafter, the operation will be described in more detail.

As shown in FIG. 1, the single-tone signal generated in the BTU 24 is used when receiving path diagnosis and measuring the voltage standing wave ratio (VSWR) of the receiving antenna.

First, during the reception VSWR measurement, the single-tone signal is switched in the RF matrix 24b of the BTU 24 and sequentially inputs to the forward port and the reverse port of the directional coupler of the front-end 22. The forward signal passes through the duplexer and the LNA, and then is input to the power measuring unit 24c of the BTU 24 through the 2-way device of the power divider 21, and the reverse signal is reflected from the antenna stage and then the power is passed through the duplexer and the LNA. It is input to the measuring part 24c.

Accordingly, the power measurement unit 24c of the BTU 24 measures RF power of the two signals (Forward / Reverse) to calculate the return loss and the voltage standing wave ratio (VSWR) of the receiving antenna. Judging whether the antenna is abnormal based on the value.

 In addition, the CPU (not shown) of the BTU 24 uses the RSSI value of the single-tone signal generated by the BTU 24 and output to the LNA of the front-end 22 to the front-end 22 and the LNA. Diagnose the receiving path of the signal, and measure the RSSI value of the single-tone signal input to the up / down converter 20 through the front-end 22 and the power divider 21, and then the up / down converter 20 after the LNA. Receive path up to) can be diagnosed.

However, the conventional transmission path diagnosis apparatus diagnoses the transmission path based on the front-end and measures the VSWR of the antenna. Therefore, since the cable, the arrester and the antenna are all included in the path diagnosis, the state of each of the cable, the arrester, and the antenna cannot be diagnosed. In addition, in the conventional transmission path diagnosis apparatus, when the cable length between the front-end and the antenna is long, there is a problem that the measurement is performed in a normal state even when the antenna is open. In particular, the voltage standing wave ratio based on the antenna (VSWR) Value could not be used to determine the state of the antenna.

In addition, the reception path diagnosis apparatus of the conventional base station can diagnose the reception path through the reverse path of the front-end (antenna → duplexer → LNA → up / down converter) using a single-tone signal generated inside the BTU. In addition, the VSWR of the antenna is measured by measuring the power of the forward and reverse paths based on the front-end.

However, the conventional reception path diagnosis apparatus of the base station also diagnoses the reception path based on the antenna port of the front-end and measures the VSWR of the antenna. Therefore, the cable, the arrester and the antenna are all included so that the reception path is diagnosed. Therefore, the states of the cable, the arrester and the antenna cannot be diagnosed, and in particular, the state of the pure antenna except the cable and the arrester cannot be determined.

Accordingly, an object of the present invention is to provide an apparatus and method capable of diagnosing a transmission / reception path between a base station and an antenna by measuring a transmission code power of the base station.

Another object of the present invention is to provide an apparatus and method for more accurately diagnosing the matching state of an antenna.

In order to achieve the above object, a transmission and reception path diagnosis apparatus of a base station according to the present invention includes: a base station transmitting a signal of a predetermined channel through an antenna; It includes a base station tester for diagnosing the transmission and reception path between the antenna at the front-end by measuring the time difference between the forward signal radiated from the front-end of the base station and the reverse signal reflected from the antenna and the frame boundary of the channel. .

Preferably, the forward signal is characterized in that the signal generated in the modem of the base station and transmitted to the front-end.

Preferably, the forward signal is characterized in that the test signal provided to the front-end in the base station test unit.

Preferably, the base station test unit diagnoses a short circuit position between the antennas in the base station by using the time difference between the frame boundary of the forward signal radiated to the antenna by the cell search and the reverse signal reflected from the antenna.

Preferably, the base station test unit measures the voltage standing wave ratio of the antenna using the code power of the forward signal radiated to the antenna and the reverse channel signal reflected from the antenna.

In order to achieve the above object, a transmission and reception path diagnosis method of a base station according to the present invention comprises the steps of: receiving a forward signal radiated to the antenna from the front-end of the base station; Receiving a reverse signal reflected back from the antenna; Remotely diagnosing the state of the antenna and the presence or absence of transmission and reception paths between the front-end and the antenna by measuring the code power of the forward and reverse signals and the temporal position of the frame boundary.

Preferably, the forward signal is generated by the modem of the base station, characterized in that the signal transmitted to the front-end.

Preferably, the forward signal is characterized in that the test signal provided to the front-end in the base station test unit.

Preferably, the diagnosing may include downconverting the signal radiated to the antenna and the signal reflected from the antenna; Converting the down-converted signal into a digital signal; Converting the digital signal into a baseband signal; Obtaining the code power of the signal converted into the baseband signal, measuring the temporal position of the frame boundary by cell color, and diagnosing the state of the antenna and the short-circuit position of the transmission / reception path between the front-end and the antenna. .

Hereinafter, preferred embodiments of the present invention will be described in detail.

3 is a block diagram of an apparatus for diagnosing a transmission path of a base station according to the present invention.

As shown in FIG. 3, the apparatus for diagnosing a transmission path according to the present invention is the same as that of FIG. 1 except for a detailed configuration of the BTU 100.

The BTU 100 includes an RF matrix 31 for receiving forward and backward RF signals from the front-end 13, a radio processor 32 for down-converting and filtering and amplifying the received RF signal, and a radio processor ( 32, an analog-to-digital converter (ADC) 33 for converting the output of the digital signal to a digital signal, an FPGA 35 for separating the output signal of the ADC 33 into I and Q signals, and a synchronization signal output from the base station ( DSP 36 for measuring the transmission power by measuring the code domains of the I and Q signals output from the FPGA 35 based on Foward_sync).

The wireless processing unit 32 converts the RF signal down-converted according to the oscillation signal Fc, a band pass filter (BPF) for filtering the output of the mixer, and amplifies the filtered signal to convert the input signal of the ADC 33. It includes an MMIC amplifier (AMP) that keeps power constant.

The FPGA 35 includes a demodulator 35a for dividing the output of the ADC 33 and down converting the output of the ADC 33 into a baseband signal, a filtering unit 35b for filtering the output of the demodulator 35a and outputting I and Q signals; An AGC (Automatic Gain Control) unit 35c for receiving the I and Q signals and outputting a gain control signal, wherein the gain control signal of the AGC unit 35c is a digital to analog converter (DAC) 34; It is fed through the MMIC amplifier (AMP).

Hereinafter, the operation of the transmission path diagnosis apparatus of the base station is as follows.

The BTU 100 receives a sample signal of a forward signal radiated from the front-end 13 to the antenna and a reverse RF signal reflected from the antenna to diagnose a fault location on the transmission path.

RF signals (forward and reverse signals) input through the RF matrix 31 of the BTU 100 are sequentially input to the FPGA 35 through the mixer, the BPF, the AMP, and the ADC 33. The demodulator 35a of the FPGA 35 down-converts the output of the ADC 33 using a mixer, and the down-converted signal is separated into an I signal and a Q signal by the filtering unit 35b.

In order to measure the power of the forward signal, the CPU of the BTU 100 can know the transmission power of the current base station through the DSP 36 and the FPGA 35 interface and can also diagnose the transmission path. In addition, the CPU uses the time difference between the forward boundary signal radiated from the antenna and the reverse signal reflected from the antenna from the power and the frame boundary found from the cell search of the corresponding channel, and the antenna from the antenna and the front-end antenna. An antenna transmission path connected to the path, that is, the cable 13a and the arrester 14 may be analyzed and diagnosed remotely.

Hereinafter, the operation of the transmission path diagnosis apparatus of the base station will be described in more detail.

In order to diagnose the state of the transmission block on the transmission path and to diagnose the abnormal position of the transmission antenna path, the BTU 100 first transmits the power of the forward signal radiated from the front-end 13 to the antenna and the power of the reverse signal reflected from the antenna. The size and temporal position of the frame boundary for a particular channel must be measured.

The BTU 100 is down-converted by mixing the channel signal (RF signal) via the front-end 13 and the RF matrix 31 with the output frequency fc of the local oscillator (not shown). The down-converted channel signal sequentially passes through the BPF and the MMIC amplifier AMP and inputs the ADC 33. The output signal of the ADC 33 is divided into two paths, and is then provided to the demodulator 35a and the filtering unit 35b. Is converted into a baseband signal. At this time, the AGC 35c controls the gain of the MMIC amplifier AMP through the DAC 34 to make the input voltage levels of the FPGA 35 and the DSP 36 constant.

The code power meter 36a of the DSP 36 receives the I and Q signals from the FPGA 35 to measure the code power. The FPGA 35 and the DSP 36 measure the frame boundary of a specific channel (I, Q). Measure

Accordingly, the CPU of the BTU 100 measures the position (T_f, T_r) and the power of the frame boundary of the channel signal (forward and reverse signals) through the FPGA 35 and the DSP 36 interface, and the ratio of the measured power. By using the voltage standing wave ratio (VSWR) can be obtained to determine the state of the antenna. Also, as shown in FIG. 4, the CPU uses a time difference between the frame boundary between the forward path and the reverse path (del_T = T_r-T_f) to connect the cable 13a and the arrester to the antenna from the front end 13. Abnormality of (14) (paragraph position: L) can be analyzed and diagnosed remotely. That is, the failure position L is obtained by the following equation (1).

L = del_T / 2 * c -------------------- Equation (1)

In this case, c represents the propagation speed of the radio wave in the antenna connection feeder.

Therefore, if a problem occurs from the front-end of the base station to the antenna, it is possible not only to accurately check the position (short-circuit position: L), but also to accurately diagnose the matching state of the actual antenna even if the person does not go out. In addition, since the transmit channel power can be measured without a measuring instrument, it is possible to know how each channel is set in the current base station.

5 is a block diagram of an apparatus for diagnosing a reception path of a base station according to the present invention.

As shown in Figure 5, the receiving path diagnostic apparatus according to the present invention is the same as Figure 2 except for the detailed configuration of the BTU 200, the detailed configuration of the BTU 200 is ULTD (Up Link transmitter Daughter) ( 47 and the RF matrix 48 are the same as the BTU 100 of FIG. 3, and thus detailed descriptions thereof will be omitted.

The ULTD 47 of the BTU 200 generates a WCDMA signal (Up-Link Code), which is a test signal, for diagnosing a reception block and verifying a failure location of an antenna reception path.

The test signal is transferred from the RF matrix 41 and sequentially input to the forward and reverse ports of the front-end 22. The forward signal and the reverse signal reflected from the antenna terminal are input to the RF matrix 48 of the BTU 200 via the LNA and the power divider 21 in the front-end 22. At this time, the RF matrix 41, 48 is switched by the CPU of the BTU (200).

The RF signal input to the RF matrix 48 is input to the ADC 43 through the RF matrix 41 through the mixer, the BPF, and the MMIC AMP of the wireless processing unit 42, and the output signals of the ADC 43 are two The signal is separated into paths and input to the demodulator 45a of the FPGA 45. The demodulator 45a converts the output signal of the ADC 43 into a baseband signal using two mixers, and the filtering unit 45b filters the baseband signal using an FIR filter to output the I and Q signals. do.

The code power meter 46a of the DSP 46 receives the I and Q signals from the FPGA 45 to measure the code power. The FPGA 25 and the DSP 26 measure the frame boundary of a specific channel (I, Q). Measure

Therefore, the code power of each signal is measured in the CPU of the BTU 200 through the interface of the DSP 46 and the FPGA 45. That is, it measures the forward power transmitted to the antenna and the reverse power reflected from the antenna, and the antenna is connected from the time difference and the power of the frame boundary found from the cell search of a specific channel to the antenna's matching state and the front-end 22 to the antenna. It is possible to remotely analyze and diagnose the reception path of, i.e., the abnormality of the cable 22a and the arrester 23.

That is, the CPU of the BTU 200 determines the state of the antenna by obtaining the voltage standing wave ratio VSWR using the code power measured by the DSP 46, and as shown in FIG. The fault position L of the antenna cable (feed line) can be found by using the time difference between the frame boundary of the forward path and the reverse path. The fault position L is obtained by equation (1).

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, in the antenna transmission / reception path diagnosing device according to the present invention, when a problem occurs from the front-end terminal of the base station to the antenna, a short-circuit position (short-circuit position: L) in the base station manager (BSM) is not directly visited by a person. And it is possible to accurately determine the matching state of the actual antenna, it is possible to know how each channel is set up (set up) at the current base station by measuring the reception code power without a measuring instrument.

In addition, the present invention can reduce the maintenance cost because it can determine the location of the failure of the antenna feed line (cable) without using a measuring instrument or a site visit.

Claims (11)

A base station transmitting and receiving a signal of a predetermined channel through an antenna; Transmitting and receiving paths between the front-end and the antenna by measuring the power of the forward signal radiated from the front-end of the base station and the reverse signal reflected from the antenna, and the time difference between the frame boundary of the forward signal and the frame boundary of the reverse signal. Transmitting and receiving path diagnostic apparatus of the base station, characterized in that consisting of the base station test unit for diagnosing the abnormality. The method of claim 1, wherein the forward signal is Transmitting and receiving path diagnostic apparatus of the base station, characterized in that the signal generated in the modem of the base station and transmitted to the front-end. The method of claim 1, wherein the forward signal is Transmitting and receiving path diagnostic apparatus of the base station, characterized in that the test signal provided to the front-end from the base station test unit. The method of claim 1, wherein the base station test unit Transceiver path diagnosis apparatus of a base station, characterized in that for diagnosing the short-circuit position between the base station and the antenna using the time difference between the frame boundary. The method of claim 4, wherein the short circuit position is Transmission and reception path diagnostic apparatus of the base station, characterized in that determined by the following equation. Paragraph position = del_T / 2 * c Here, del_T is the frame boundary position of the reverse signal-the frame boundary position of the forward signal, and c is the propagation speed of the radio wave at the antenna feed line. The method of claim 1, wherein the base station test unit Transceiving path diagnostic apparatus of the base station characterized in that the voltage standing wave ratio of the antenna is measured using the code power of the forward signal radiated to the antenna and the reverse channel signal reflected from the antenna. Receiving a forward signal radiated to the antenna at the front-end of the base station; Receiving a reverse signal reflected back from the antenna; Transmitting and receiving the base station, comprising remotely diagnosing the state of the antenna and the abnormality of the transmission / reception path between the front-end and the antenna by measuring the code power of the forward signal and the reverse signal and the temporal positional difference between the frame boundaries. Path diagnosis method. The method of claim 7, wherein the forward signal is Transmitting and receiving path diagnostic method of a base station characterized in that the signal generated in the modem of the base station and transmitted to the front-end. The method of claim 7, wherein the forward signal is Transmitting and receiving path diagnostic method of a base station, characterized in that the test signal provided to the front-end from the base station test unit. The method of claim 7, wherein the diagnosing step Downconverting the signal radiated to the antenna and the signal reflected from the antenna; Converting the down-converted signal into a digital signal; Converting the digital signal into a baseband signal; The code power of the signal converted into the baseband signal is calculated, and the temporal position of the frame boundary is measured by cell color, and the state of the antenna and the short-circuit position of the transmission / reception path between the front-end and the antenna are diagnosed. Transmitting and receiving path diagnostic method of a base station. The method of claim 10, wherein the short circuit position is Transmitting and receiving path diagnostic method of a base station characterized in that determined by the following equation. Paragraph position = del_T / 2 * c Here, del_T is the frame boundary position of the reverse signal-the frame boundary position of the forward signal, and c is the propagation speed of the radio wave at the antenna feed line.

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