KR100490309B1 - Measurement apparatus of VSWR of receiving antenna in mobile communication system - Google Patents

Abstract

In the mobile communication system, in particular, the standing wave ratio of the receiving antenna among the duplex base station antennas can be measured more accurately. In the mobile communication system according to the present invention, the standing wave ratio measuring apparatus of the receiving antenna is a single frequency. A base station performance test board for embedding a single tone generator for generating and outputting a signal and for controlling forward and reverse paths; A transmit / receive antenna which simultaneously performs transmission and reception functions, and a reception antenna which performs reception only functions; A bidirectional coupler for connecting the receive-only and transmit / receive antennas to a base station performance test board and a base station system, respectively, to extract signals input in a forward path and a reverse path; Receiving field strength detecting means for calculating received signal strengths of the forward and reverse paths of the receiving antenna from the bidirectional coupler; And a base station processor for measuring the voltage standing wave ratio of the receiving antenna by using the difference between the forward received signal strength and the reverse received strength detected by the received field strength detecting means.

Description

Measurement apparatus of VSWR of receiving antenna in mobile communication system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base station performance test apparatus of a mobile communication system, and particularly, to accurately measure a standing voltage ratio (hereinafter, referred to as VSWR) of a duplex type reception antenna so as to be suitable for testing normal operation of a base station. The present invention relates to a receiving antenna standing wave ratio measuring apparatus in a mobile communication system.

In general, in a mobile communication system based on code division multiple access (CDMA), a base station includes two antennas. In this case, a type in which each antenna performs a transmission function and a reception function separately is called a simplex antenna, one antenna simultaneously performs a transmission and a reception function, and the other antenna performs a reception-only function. This form is referred to as a duplex antenna.

Currently, the mobile communication system measures the standing voltage ratio (VSWR) of the base station antenna by using a base station performance test measurement device which performs normal operation diagnosis and various tests of the base station.

By using the voltage standing wave ratio, the operator can know the current operation of a specific frequency (FA) of a base station and a specific antenna. Therefore, when the voltage standing wave ratio (VSWR) for a particular FA exceeds a predetermined range compared to a reference value that is already set, the operator malfunctions in the performance of the antenna and base station devices that are communicating with the mobile terminal through the FA. You can detect that you are doing.

A standing wave ratio measuring method of a conventional duplex type receiving antenna will be described below. 1 is a block diagram illustrating a base station test apparatus in a conventional mobile communication system.

1, a base station performance test board 100 having a test terminal 101 and measuring the standing wave ratio of the virtual call and the base station antenna to check whether the base station is in normal operation; A transmit / receive antenna 121 and a receive-only antenna 122; First and second bidirectional couplers 123 and 124 connected between the antennas 121 and 122 and the antenna connection terminals of the base station to extract signals transmitted and received; A first duplex (D / X) 125 for separating the signal input from the first bidirectional coupler 123 connected to the transmit / receive antenna 121 into a transmit signal and a receive signal, respectively; A reception filter (RxF) 128 for filtering a signal input from the second bidirectional coupler 124 connected to the reception-only antenna 122; Low noise amplifiers (LNAs) 126 and 129 coupled to the first duplex 125 and the receive filter 128, respectively; A power amplifier 127 for power amplifying the transmission signal and transferring it to the duplex 125; An up / down converter 130 for up / down converting a transmit / receive signal; A channel card (Ch card) 131 for comparing the noise ratio (Eb / No) of the signal transmitted from the terminal 101 through the up / down converter 130 with a reference noise ratio and indicating a result; A base station processor which controls the output signal strength of the terminal according to the message transmitted from the channel card 131 and reads the signal strength transmitted through the forward and reverse paths (FOR, REV) and calculates the standing wave ratio (VSWR) of the receiving antenna. A base station processor (BSP) 132; A base station module 133 connected to the base station processor 132 and providing a user interface; The alarm board 134 transfers the information transmitted from the base station processor 132 to the base station performance test board 100 and collects various alarm / data information.

 The base station performance test board 100 includes a test terminal 101 and a path selector 110 to select a path of a virtual call of the mobile communication terminal 101. The path selector 110 may include a second duplex 111 for separating the virtual call of the mobile communication terminal 101 into a transmission / reception signal, and first and second attenuators 112 and 113 for adjusting the magnitude of the transmission and reception signals. And third and fourth duplexes 114 and 115 for separating the signals input from the first and second attenuators 112 and 113 into transmit and receive signals, and the outputs of the third and fourth duplexes in a forward or reverse path. The first and second SPDTs 116 and 117 output to the first and second bidirectional couplers.

Referring to the accompanying drawings for the base station performance test apparatus of the conventional mobile communication system as described above are as follows.

First, the base station performance test board (BADA) 100 is a board that checks the normal operation of the base station by measuring the standing wave ratio of the virtual call and the base station antenna.

The base station performance test board 100 includes a test terminal (MS) 101 and a path selector 110 for transmitting / receiving path separation and signal attenuation and path switching.

As shown in FIG. 2, the first bidirectional coupler 123 is connected between the transmit / receive antenna 121 and the antenna body system via a transmit / receive antenna cable, so that the forward path from the system to the test terminal 101. (A_FOR) and the transmit / receive antenna reverse path (A_REV) from the system to the test terminal.

The second two-way coupler 124 is connected between the receiving antenna 122 and the antenna body system via a receiving antenna cable to receive the forward path B_FOR from the system to the test terminal 101 and the system to the test terminal. Configure the antenna reverse path (B_REV).

To this end, the path selector 110 is connected to the first and second bidirectional couplers 123 and 124 to separate the transmission and reception signals output from the test terminal 101 and to attenuate the separated signal to a predetermined magnitude. Transfer to the appropriate path.

The standing wave ratio measurement of the reception antenna Rx of the reception-only function and the reception function will be described below.

When the test terminal 101 outputs a call having a predetermined intensity, the second duplex 111 of the path selector 110 separates the received signal Rx from the input signal and causes the second attenuator ATT. An attenuator 113, and the second attenuator 113 adjusts the size of the received signal and outputs the received signal to the receiving terminals Rx of the third and fourth duplexes 114 and 115.

The third and fourth duplexes 114 and 115 separate the received signal from the input signal and output the received signal to the first and second SPDTs 116 and 117, respectively. The first and second SPDTs 116 and 117 send forward power to the first and second bidirectional couplers 123 and 124 on the forward paths A_FOR and B_FOR.

At this time, the forward power of the first and second bidirectional couplers 123 and 124 is transmitted to the antenna connection terminal of the system without passing through the antenna. Then, the forward power of the first bidirectional coupler 123 is transmitted to the channel card 131 through the first duplex 125, the low noise amplifier 126, the up / down converter 130, and the second bidirectional coupler ( Forward power of 124 is delivered to channel card 131 through receive filter 128, low noise amplifier 129, and up / down converter 130.

The channel card 131 analyzes the signal-to-noise ratio (Eb / No) of the call transmitted from the test terminal to the forward path, compares it with the reference signal-to-noise ratio set therein, and if it matches the reference value, it is normal to the test terminal 101. Send a message.

Then, the test terminal 101 transmits the call in the reverse path with the same signal strength as it receives the message from the base station is normal. At this time, the path selector is switched to the reverse path.

However, as shown in FIG. 2, when the reverse power delivered to the reverse path is compared with the forward power, the difference occurs as much as the return loss of the antenna, and to compensate for this, the channel card transmits the difference to the terminal. Send a message to raise the number.

Therefore, the test terminal 101 outputs reverse power by raising a signal until receiving a message of normal from the base station.

When the base station processor 160 receives the normal message from the channel card 150, the base station processor 160 reads the strength of the signal in the forward and reverse directions, and calculates the standing wave ratio VSWR of the receiving antenna Rx by using the read signal strength. The received message is transmitted to the base station module (BSM) 133 to inform the operator. Here, the alarm board 134 connects the base station processor 132 and the base station test board 100, and is responsible for collecting alarms / data generated from each board.

The standing wave ratio measurement method of the conventional base station receiving antenna measured through such a path uses a closed loop power control function between the base station and the test terminal. That is, in the closed loop power control, the transmission output of the test terminal 101 by the base station is adjusted.

Therefore, the standing wave ratio measurement of the base station receiving antenna is connected to the main signal path between the base station and the receiving antenna to make a port for the forward path and the reverse path by connecting the bidirectional coupler, and then the path where the forward path and the reverse path of the receiving antenna are connected. In the selection unit, the incidence path of the coupler is transferred to the forward path, and then a Markov arc is set. At this time, measure the transmit power of the test terminal.

Subsequently, the path selector 110 transfers the reception path to the reflection path and then measures the transmission power of the test terminal.

Equation 1 is a formula for measuring the standing wave ratio.

Here, P _dBRVS is the output power of a mobile terminal for a reflection path of the coupler, _dBFWD P is the output power of a mobile terminal to the incident path of the coupler. Also, tau is a reflectometer and P _d is the difference in output power of the test terminal when the call is set up through the reflection and the incident path of the coupler.

In this way, if both standing antennas (Rx) are measured and the standing wave ratio is measured, the standing antenna standing wave ratio of the base station is normally about 1: 1.43, but the standing wave of this antenna is opened when the antenna is opened apart from the base station transmission line. The ratio will increase to 1: 1.8 or higher. As a result, the operator can determine whether the antenna is abnormal based on the measured standing wave ratio.

However, in the conventional base station test apparatus, the reference noise ratio (Eb / No) possessed by the channel card changes every time according to the base station operating environment. In other words, due to the influence of other terminals, external noise, power control error due to time delay occurs, the accuracy is much lowered. In addition, in order to compensate for the measurement error, the measurement time is delayed by repeatedly performing the measurement several times.

An aspect of the present invention provides a device for measuring the standing wave ratio of a receiving antenna in a mobile communication system capable of measuring the standing wave ratio of a receiving antenna using a single tone generator instead of using a test terminal embedded in a base station performance test board. Has its purpose.

Another feature of the present invention is to measure the single tone strength in the RSSI circuit and transmit it to the base station processor, so that the difference in the signal strength input to the forward path and the reverse path of the receiving antenna to calculate the standing wave ratio of the receiving antenna An object of the present invention is to provide an apparatus for measuring standing wave ratio of a receiving antenna in a mobile communication system.

Another feature of the present invention is that since the test terminal is not used as in the prior art, since the power control function and the closed loop power control of the base station are not used, the measurement error is reduced without being affected by the commercial terminal being connected. An object of the present invention is to provide a standing wave ratio measuring device of a receiving antenna in a mobile communication system capable of shortening and reducing an error range.

In the mobile communication system according to the present invention, the standing wave ratio measuring apparatus of the receiving antenna,

A base station performance test board for embedding a single tone generator for generating and outputting a single frequency signal and for controlling forward and reverse paths;

A transmit / receive antenna which simultaneously performs transmission and reception functions, and a reception antenna which performs reception only functions;

A bidirectional coupler for connecting the receive-only and transmit / receive antennas to a base station performance test board and a base station system, respectively, to extract signals input in a forward path and a reverse path;

Receiving field strength detecting means for calculating received signal strengths of the forward and reverse paths of the receiving antenna from the bidirectional coupler;

And a base station processor for measuring the voltage standing wave ratio of the receiving antenna by using the difference between the forward received signal strength and the reverse received strength detected by the received field strength detecting means.

Preferably, the base station processor calculates the standing wave ratio of the receiving antenna by using the received signal strength in the forward path and the received signal strength in the reverse path only once.

Preferably, the receiving field strength detecting means detects the signal strength inputted in the forward and reverse paths from the bidirectional coupler connected to the receiving antenna, converts it into a hexa code, and transmits the signal to the base station processor.

Preferably, the receiving field strength detecting means is provided in the up / down converter.

Hereinafter, with reference to the accompanying drawings as follows.

3 is a block diagram illustrating an apparatus for measuring standing wave ratios of a receiving antenna according to the present invention.

Referring to FIG. 3, a test terminal 201, a single tone generator 202, and a path selector 210 for path switching are performed to measure the standing wave ratios of the single tone and the base station antenna to check whether the base station operates normally. A base station performance test board 200 having; A transmit / receive antenna 221 and a receive-only antenna 222; First and second bidirectional couplers 223 and 224 connected between the antennas 221 and 222 and the antenna connection terminals of the base station to extract signals transmitted and received; Low noise amplifiers (LNAs) 225 and 226 connected to the first and second bidirectional couplers 223 and 224; A power amplifier 227 for power amplifying the transmission signal; An up / down converter 230 having an RSSI circuit 231 for up / down converting a transmit / receive signal and detecting signal strengths in a forward path and a reverse path of a receiving antenna; A channel card (Ch card) 232 for transmitting the received signal strength transmitted from the RSSI circuit 231; A base station processor (BSP) 233 that calculates standing wave ratios of the receiving antennas using difference in signal strengths of the forward and reverse paths of the receiving antennas transmitted from the channel card 232; A base station module 234 connected to the base station processor 233 to provide a user interface; The alarm board 235 transfers the information transmitted from the base station processor 233 to the base station performance test board 200 and collects various alarm / data information.

Referring to the accompanying drawings, a base station test apparatus in a mobile communication system according to the present invention is as follows.

Referring to FIG. 3, the base station performance test board 200 includes a test terminal 201, a singleton generator 202, and a path selector (S / W) 210.

Referring to the measurement of the standing wave ratio of the receiving antenna, the single tone generator 202 outputs a sine wave in which only a single frequency exists, and the output signal of the single tone generator 202 is forward path and reverse path in the path selector 210. It is alternately outputted.

The signal output from the path selector 210 to the forward path is output to the low noise amplifiers 225 and 226 through the incidence paths of the first and second bidirectional couplers 223 and 224, and the low noise amplifiers 225 and 226 are up / down converters 230. RSSI circuit 231 detects the received signal electric field strength and converts it to a hexa code. The signal strength converted into the hexa code is transmitted to the base station processor 233 through the channel card 232.

Subsequently, when switched to the reverse path, the tone signal of the single tone generator 202 is transmitted to the first and second bidirectional couplers 223 and 224 through the reverse path of the path selector 210 and then returned to the receiving antenna Rx. And then back to the low noise amplifiers 225,226.

Then, the received signal strength indicator (RSSI) circuit 231 of the up / down converter 230 receiving the signal strength of the reverse path from the low noise amplifiers 225 and 226 detects the received signal field strength of the reverse path and then checks the hexa code. Convert it to and pass it to the channel card. The channel card 232 delivers the hexa code to the base station processor 233.

Then, the base station processor 233 calculates the difference between the signal strength of the forward path and the reverse path of the received antenna, and measures the standing wave ratio VSWR.

Therefore, since the power control function of the base station is not used, the standing wave of the receiving antenna is calculated by calculating the difference in signal strength by a single measurement using the RSSI circuit, that is, the receiving field strength detecting means, without being affected by the commercial terminal being connected. By measuring the ratio, the measurement time can be shortened and the error range can be reduced.

As described above, according to the method for measuring the performance of the reception antenna of the base station in the mobile communication system according to the present invention, the terminal built in the existing base station performance test board does not use the closed-loop power control of the base station, but rather a single tone. By using the generator and adding the RSSI circuit, the standing wave ratio of the receiving antenna can be measured only once.

In addition, the measurement time can be shortened and the error range can be reduced as in the case of using a measuring instrument, and the standing wave ratio of the receiving antenna can be measured more accurately.

1 is a block diagram showing a base station performance test apparatus in a conventional mobile communication system.

2 is a diagram illustrating a connection between a base station performance test apparatus and an antenna in a conventional mobile communication system.

3 is a block diagram illustrating an apparatus for measuring standing wave ratios of a receiving antenna in a mobile communication system according to an exemplary embodiment of the present invention.

<Brief description of symbols for the main parts of the drawings>

200 ... Base Station Performance Test Board 201 ... Test Terminal

202 ... Single tone generator 210 ... Path selection

221 ... transmit / receive antenna 222 ... receive-only antenna

223,224 Bidirectional coupler 225,226 Low noise amplifier

230 ... up / down converter 231 ... RSSI circuit

232 control board 233 base station processor

234 base station module

Claims (4)

A base station performance test board including a single tone generator for outputting a sine wave having only a single frequency, and a path selector for sequentially switching the output signal of the single tone generator into a forward path and a reverse path; A transmit / receive antenna which simultaneously performs transmission and reception functions and a reception antenna which performs reception only functions; A bidirectional coupler for connecting the receive-only and transmit / receive antennas to a base station performance test board and a base station system, respectively, to extract signals input in a forward path and a reverse path; Receiving field strength detecting means for calculating received signal strengths of the forward and reverse paths of the receiving antenna from the bidirectional coupler; And a base station processor for measuring the voltage standing wave ratio of the receiving antenna by using a difference between the forward received signal strength and the reverse receiving strength detected by the receiving field strength detecting means. Device. The method of claim 1, And the base station processor calculates the standing wave ratio of the receiving antenna using the received signal strength in the forward path and the received signal strength in the reverse path only once. The method of claim 1, The receiving field strength detecting means measures the standing wave ratio of the receiving antenna in the mobile communication system, which detects the signal strength inputted in the forward and reverse paths from the bidirectional coupler connected to the receiving antenna, converts it into a hexa code, and transmits the signal to the base station processor. Device. The method of claim 1, The receiving field strength detecting means is a standing wave ratio measuring apparatus of a receiving antenna in a mobile communication system, characterized in that the circuit is a received signal stability indicator (RSSI) provided in the up / down converter.