KR100537472B1 - System for monitoring base station using code domain analysis and methode thereof - Google Patents

Abstract

The present invention relates to a system and method for remotely monitoring the status of a base station.

The base station monitoring system according to the present invention includes a base station status meter connected to a transmission antenna of a base station and a base station monitoring server connected through a network with the base station status meter. The base station condition meter includes a code domain analyzer to transmit a code domain signal to the base station monitoring server. The base station monitoring server restores the transmitted code domain signal and determines whether there is an abnormal state of the base station.

According to the configuration of the present invention, quantitative analysis of the base station transmission power is possible regardless of the call volume and the wireless environment.

Description

System for monitoring base station using code domain analysis and methode}

The present invention relates to a system and method for monitoring a CDMA mobile communication base station status and communication environment. More specifically, the present invention relates to a monitoring system and method capable of quantitatively analyzing base station status and communication environment for each frequency.

1 is a schematic diagram showing a prior art CDMA base station transmission output measurement system.

In the prior art, in order to monitor the state of the base station 10, the spectrum analyzer 20 is connected to the coupler 15 of the transmission antenna 14 to monitor the transmission output. The spectrum analyzer 20 is connected to the transmitting end of the base station to convert the output signal into the frequency domain to represent.

The spectrum analyzer 20 reconstructs the shape of the energy spectrum for each frequency channel FA. The spectrum analyzer 20 may include a transmission power meter to display the magnitude of power together with the spectral form of the transmission output of the base station.

2 illustrates a remote monitoring system of a base station in the prior art.

The base station state measuring instruments installed in the plurality of base stations 10a, 10b, and 10c are connected to the monitoring server 40 via a mobile communication switching center (BSC) 30. The base station state measuring instrument is equipped with the above-described spectrum analyzer to configure the spectrum for each FA to transmit to the monitoring server 40 using the E1 transmission path.

The monitoring server 40 periodically receives a graphic of the spectrum for each FA and determines the abnormal state of the base station based on the shape. However, if the state of the base station is monitored using the graphic of the spectrum, excessive traffic is imposed on the E1 transmission path. This is because a spectral graphic can realize a more detailed spectral shape only when its resolution is higher, so that the amount of data increases as the frequency corresponding to the energy value is subdivided. That is, in order to observe the spectrum of one FA, corresponding values for each frequency are transmitted as data, and when the spectrums of a plurality of FAs and a plurality of base stations are simultaneously transmitted to the monitoring server 40, the traffic increases and the E1 transmission path May become saturated. The saturation of these transmission paths can interfere with real-time base station monitoring.

In addition, base station monitoring using such spectrum analysis has a fatal problem in quantitative analysis.

3A and 3B show output signals for each FA output from the spectrum analyzer.

The output signal for each FA is concentrated at a specific frequency to form a spectral graphic in a trapezoidal shape as shown in FIG. 3A.

On the other hand, in the case of transmitting a continuous FA spectrum such as FA1 and FA2, a portion where the spectrum overlaps, such as a hatched portion (a) occurs. This overlap (a) occupies about 3% of the entire spectrum.

However, as illustrated in FIG. 3B, waveform distortion may occur in the overlapped portion (a) of the spectrum of FA1 and the spectrum of FA2. In this case, since the monitoring server 40 cannot observe the distortion of such a waveform, there is a problem in that the abnormal state of the base station cannot be accurately monitored.

In addition, when the distortion of the spectrum of FA4 shown in FIG. 3B is observed by the monitoring server 40, the operator judges that there is an abnormality of the base station state. However, the distortion of the waveform alone cannot quantitatively determine the abnormal state of the base station. This is because the distortion of the waveform may be caused by any of the baseband processor, the intermediate frequency processor, and the RF processor.

Moreover, since the distortion of the spectrum is not only caused by the base station, but also depends on the call state, the monitoring server 40 only determines that there is an error in the transmission output, and there is no way to know what is causing it. .

FIG. 4 is a diagram for describing an intermodulation distortion (IMD) phenomenon of a transmission signal caused by a nonlinear device.

IMD is a phenomenon caused by nonlinear devices such as high power amplifiers in a base station. As such, a signal in which a new frequency signal, which is not present at the input, appears at the output due to the nonlinear characteristic of the device is called an IMD signal. This IMD phenomenon is particularly serious when the input signal is composed of several frequency components.

When the spectra of the center frequencies f1 and f2 pass through the nonlinear amplifier 17, component signals of 2f1-f2 and 2f2-f1 are generated near the bandwidth. The two unwanted signals cause the bandwidth of the IMD signal to be twice that of the input signal.

Therefore, in the graphics implemented in the spectrum analyzer, a wide bandwidth IMD signal is generated, and the distortion of the spectrum becomes unobservable. In the case of a multi-FA, when a signal of a continuous spectrum is output, there is a problem that the IMD measurement is also impossible when the IMD signals overlap each other in the overlapped portion a shown in FIG. 3A.

Therefore, the base station monitoring system using the spectrum analyzer has a number of problems that can not be quantitative analysis of the state of the base station, and IMD measurement of the transmission signal is impossible.

The present invention provides a base station remote monitoring system and monitoring method capable of quantitative analysis of a base station transmission signal.

The present invention also provides a base station remote monitoring system and monitoring method capable of measuring the IMD of a transmission signal.

The present invention also provides a base station remote monitoring system and monitoring method capable of monitoring a base station regardless of traffic conditions.

In addition, the present invention provides a base station remote monitoring system and monitoring method for identifying and warning the cause of the abnormal state of the base station in conjunction with the software.

In order to achieve the above technical problem, a base station monitoring system according to an aspect of the present invention includes a base station state measuring instrument including a code domain analyzer mounted to the transmitting antenna of the base station; A base station monitoring server connected via a network with the base station instrument,

The base station monitoring server may include a code domain signal processor configured to process a code domain signal transmitted from the base station state meter; A display unit configured to recover the code domain signal and display a digital gain for a code corresponding to each channel; A UOCN monitoring unit for monitoring noise of an unoccupied channel from the code domain signal; And an abnormal state alarm for alarming an abnormal state of the base station according to the output of the UOCN monitoring unit.

Here, the UOCN monitoring unit monitors whether the digital gain of the noise of the non-occupied channel is greater than or equal to the threshold, and if the threshold is exceeded, alerts that there is an error in the transmission linearity of the base station.

In addition, the base station monitoring system according to another aspect of the present invention includes a base station state measuring instrument including a code domain analyzer mounted to the transmitting antenna of the base station; A base station monitoring server connected through the network with the base station status meter;

The base station monitoring server includes: a transmission signal power measurement unit for measuring the power of the transmission signal transmitted from the base station state measuring instrument; A code domain signal processor extracting a digital gain of a specific channel from the code domain signal transmitted from the known state meter; An absolute power value calculator for calculating an absolute value of the power of the specific channel from the power of the transmission signal output from the power measuring unit and the code domain signal processor and the digital gain of the specific channel; And an abnormal state monitoring unit that monitors an absolute value of a specific channel output from the power calculating unit and monitors an abnormal state of the specific channel.

The specific channel may be a pilot channel, and the base station monitoring server may further include a first abnormal state alarm unit that alerts an abnormal state when the absolute value of the pilot channel monitored by the abnormal state monitoring unit is not constant. can do.

The base station server may further include a wireless terminal for receiving an RF transmission signal of a predetermined base station; A first signal to noise ratio measuring unit for measuring a signal to noise ratio of a pilot channel from the wireless terminal; The apparatus may further include a second signal-to-noise ratio measurement unit configured to measure a signal-to-noise ratio of the pilot channel from the absolute value of the pilot channel power output from the absolute power value calculator and the power of the transmission signal.

The abnormal state monitoring unit may monitor the abnormal state of the base station wireless environment by comparing the first signal-to-noise ratio output from the first signal-to-noise ratio measurement unit with the second signal-to-noise ratio calculated by the second signal-to-noise ratio measurement unit. have.

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. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

Now according to an embodiment of the present invention will be described in detail with reference to the drawings.

5 is a block diagram showing a CDMA base station state measurement system according to an embodiment of the present invention.

As shown in FIG. 5, a code domain analyzer 100 is connected to the coupler 15 of the transmit antenna 14 of the base station. The code domain analyzer calculates and transmits the digital gain corresponding to each Walsh code in units of dB for each FA.

The code domain analyzer 100 may digitize power corresponding to 64 Walsh codes and display the bar graph. The code domain analyzer 100 may be connected to the E1 transmission path to transmit code domain analysis data to a remote monitoring server via a mobile communication switching center (BSC).

The remote monitoring server receiving the code domain analysis data from the plurality of base stations may classify the data by base stations and FAs and restore and monitor digital values of power corresponding to the respective codes.

Therefore, since only the digital data corresponding to the data and the code value transmitted through the E1 transmission path are transmitted, the traffic amount is significantly reduced compared to the spectrum analyzer described above. Therefore, the saturation problem of the transmission path hardly occurs.

6 is a block diagram showing the configuration of a code domain analyzer used in an embodiment of the present invention.

The code domain analyzer 100 generally includes a down converter unit 110 including an RF processor 111, an IF processor 112, and a baseband processor 113, and an analog-to-digital converter (ADC) 114. And a code domain power measurement unit 120, a central processor 130, and a data output unit 140.

The down converter 110 processes the RF transmission signal received from the coupler 15 of the transmission antenna 14 and down-converts the baseband signal. The down-converted signal is converted into a digital value through the ADC 114 and transmitted to the code domain power measurement unit 120. The central processor 122 calculates power level data corresponding to the code by calculating the digital value and the power measured by the code domain power measurement unit 120 and outputs the power level data corresponding to the code to the outside through the data output unit 140.

Data output through the data output unit 140 will be transmitted to the remote base station monitoring server via the E1 transmission path.

FIG. 7 is a block diagram illustrating a configuration of the code domain power measurement unit 120 illustrated in FIG. 6.

The code domain power measurement unit 120 used in the embodiment of the present invention includes an automatic gain control unit 121, a DC offset control unit 122, a CDMA synchronization unit 123, a power measurement unit 124, and a memory unit ( 125).

The digital value of the output signal transmitted to the ADC 114 controls the amplitude of the output signal received through the automatic gain control unit 121 to be a constant value. The automatic gain controller 121 adjusts the gain of the receiver to maintain the output of the ADC 114 at a desired level.

The DC offset controller 122 measures a DC level offset generated by the ADC 114 to generate a correction signal. The CDMA synchronization unit 123 synchronizes the CDMA signals, and the power measurement unit 124 measures the power of each channel with respect to the synchronized signals and stores them in the memory 125.

The central processor 130 controls the above-described power measurement operation and allows the power level corresponding to the code channel to be stored in the memory 125.

8 shows data output from an analyzer of the code domain.

The forward CDMA channel consists of a pilot channel, up to one sync channel, up to seven call channels, and a plurality of forward call channels. Each of these code channels is orthogonally spread by the Walsh function.

The 64 code channels allocated here consist of a pilot channel (Pi) which is always used, a synchronization channel (Sync), a paging channel (Pa), and a plurality of call channels (Tr1, Tr2). Corresponding. Here, the pilot channel, the synchronization channel, and the paging channel are called overhead channels, and perform a broadcasting operation regardless of the number of users.

The code domain analyzer displays, in dB, the digital gain of the code corresponding to the code number corresponding to each of these channels. Therefore, it is possible to accurately grasp the state of the overhead channel regardless of the increase or decrease of the call volume.

As shown in FIG. 8, noise generated in an unoccupied channel other than the currently used channels Pi, Pa, Tr1, and Tr2 is called unoccupied code noise (UOCN). All code gains present in this UOCN are noise components. The gain of the noise component of this UOCN is limited to not exceed a certain threshold (eg, 27 dB or 29 dB). As shown in FIG. 8, it can be seen that the code number Wx exceeds the threshold Gth, which indicates that an error has occurred in the base station state.

In the embodiment of the present invention, the data transmitted through the code domain analyzer may quantitatively analyze the IMD at the remote base station server and determine whether the overhead channel is damaged.

9 is a block diagram illustrating a configuration of a monitoring server that performs IMD analysis according to an embodiment of the present invention.

Base station monitoring server 200 according to an embodiment of the present invention is the transmission and reception interface 210, FA selection unit 220, code domain signal processing unit 230, digital gain display unit 240, memory unit 240, UOCN The monitoring unit 260 and the abnormal alarm unit 270 are included.

The information of the transmission output from the code domain analyzer 100 described above is transmitted to the base station monitoring server 210 via the E1 transmission path. Prior to the transmission, the monitoring server 200 may request a code domain signal of a desired FA from the base station using the FA selection unit 220.

The code domain signal processor 230 extracts data necessary for code domain analysis from the received transmission output information. The extracted data displays the digital gain corresponding to each channel in the digital gain display unit 240. The code domain analysis data is classified by time, base station and FA and stored in the memory unit 250.

The UOCN monitoring unit 260 identifies an unoccupied channel among data transmitted from the code domain signal processing unit and monitors whether the gain of the UOCN exceeds a specific threshold value. According to the monitoring result of the UOCN monitoring unit 260, the abnormality alarm unit 270 notifies the operator when an abnormality of the base station state is detected.

10 is a flowchart illustrating a method of performing IMD analysis according to an embodiment of the present invention.

The base station monitoring server selects a specific FA of the base station to monitor the output state (S100). If the FA is selected, a code domain signal including digital gain information corresponding to each channel of the selected FA is received (S110). The received information is processed and displayed to display a digital gain corresponding to each channel in a bar graph (S150).

In addition, information about the UOCN of the non-occupied channel is extracted from the signal obtained by analyzing the code domain (S130). The non-occupied channel is determined in the baseband, and information about the non-occupied channel can be easily obtained from a base station through a transmission / reception interface.

The digital gain of the extracted UOCN is managed and monitored separately and compared with the threshold level (S130). The threshold level is different for each mobile communication system, but is limited to about 27 dB or 29 dB. If the gain value of the UOCN exceeds the threshold level, the monitoring server generates an abnormal alert to inform the abnormal state of the base station (S140).

In addition, the threshold level can be determined based on the specification of the IMD. The IMD standard corresponds to the size of the IMD component generated in FIG. 4. In other words, the IMD standard is a measure for determining the linearity of the elements of the base station. According to the conventional spectral analysis, the comparison with the IMD standard is impossible in the continuous signal, and the comparison with the IMD standard is very difficult because the instantaneous variation of the spectrum is too large. Moreover, the IMD component of the spectrum is not only affected by the linearity of the device but can be distorted when the call state worsens.

However, according to this embodiment, since code domain information for each FA can be observed, IMD analysis is not disturbed by output signals of other FAs. In addition, the code domain information is calculated as a digital value. Since the digital gain of the UOCN does not increase at all even when the call state is in the worst case (pole capacity), the abnormality of the base station hardware state can be accurately determined.

Therefore, as shown in FIG. 8, when the UOCN exceeds the threshold level Gth in the non-occupied channel Wx, it is possible to accurately observe that a problem with the linearity of the base station device has occurred, and thus it is immediately known. do. If the abnormality alarm occurs, it is possible to take action.

11 is an observation diagram showing a change in output of a CDMA base station.

In the city center, the output of the CDMA base station varies greatly even with a short unit time. As shown in the observation diagram shown in FIG. 11, a change in output up to 6 dB at 1.25 ms is observed. This change in output is caused by fluctuations in the call volume, fluctuations in the output of the talk channel in the voice activated state, fluctuations in output for each talk channel by forward power control, and the like.

Therefore, even if the output power of the base station is measured by such a change amount, it is difficult to determine whether the value is lower than the normal value. Since the output power of the base station is related to the call volume, an abnormality in output of an overhead channel such as a pilot channel is difficult to observe.

Fig. 12 shows components of the output of the CDMA base station at the time of no call and at the maximum call.

The output of the CDMA base station is composed of a pilot channel Pi, a sync channel, a paging channel Pa, and a traffic channel as described above. The pilot channel, sink channel, and paging channel are always output regardless of a call, and are collectively called an overhead channel.

If there is no call, only the overhead channel is output. If there is a call, the output of the traffic channel is added according to the call volume. The power of the traffic channel excluding the power of the overhead channel is about 5-6 dB, but may vary for each CDMA system.

FIG. 13 is a graph illustrating the output of a base station output and a pilot channel over time. FIG.

The graph shown in FIG. 13 shows the base station total output power Pt, the power Pp of the pilot signal appearing on the code domain, and the absolute value Ppm of the power of the pilot channel.

Base station total output power (Pt) has the highest value around 12 o'clock the highest call volume, it can be seen that the value decreases after 12 o'clock at night. On the contrary, the power Pp of the pilot signal is the highest after 12 pm when the call volume decreases, and the value decreases gradually in the afternoon. These observations may vary according to local factors, and the results shown in FIG. 13 are only examples.

On the other hand, since the pilot channel is substantially always a broadcasting channel, the absolute value of the power of the pilot signal is kept constant throughout the day.

On the other hand, in the prior art, in order to check the abnormal state of the pilot channel, the power of the pilot channel is observed only at dawn time, and how far apart from the average value for several days as a criterion of the ideal state, but this is the call state at all There was a problem with the accuracy because it is not an excluded observation. Therefore, it was difficult to clearly monitor whether the pilot channel defect occurred because the change in the pilot power was caused by the call state defect or whether the problem occurred in the pilot channel processor. In addition, it is difficult to accurately measure the power of the pilot signal as the instantaneous change in power as shown in FIG.

Meanwhile, in the related art, when the reception strength of a pilot channel of a terminal is referred to as Ec, and the total noise including both the neighbor base station noise and the traffic channel noise is referred to as Io, the Ec / Io is measured using a terminal to measure the base station. Check for abnormal transmission conditions. However, although Ec / Io is a kind of signal-to-noise ratio factor, it can also be degraded by the call volume and the adjacent cell, and thus cannot be an accurate measure for determining the degradation of the transmitter of the base station.

14 is a block diagram showing the configuration of a base station remote monitoring server according to a second embodiment of the present invention.

Transmission power calculation unit 320, code domain signal processing unit 330, pilot power for receiving and processing code domain information from the base station through the base station monitoring server 300, the transmission and reception interface 310, the E1 transmission path of the present invention The calculator 340 is included. In addition, the wireless terminal 360 and a first Ec / Io measuring unit 370 for measuring the Ec / Io for the base station signal received from the wireless terminal 360.

The monitoring server 300 may further include a second Ec / Io measurement unit, an abnormal state monitoring unit 380, and first to third abnormal states that mathematically calculate Ec / Io based on information from a pilot power calculation unit. It further includes a report unit (390, 391, 392).

The operation of the monitoring server will be described below.

First, the wireless terminal 360 receives a transmission signal of a specific base station and measures the Ec / Io of the pilot channel in the first Ec / Io measurement unit. Assuming that the pilot signal is about 20% of the total output and the Ec / Io has a value of -7 dB at a maximum of -1 dB without considering the influence of adjacent cells. That is, during a non-call, it has a value of about -1 dB, and the Ec / Io value changes between 0 and -6 dB according to the change in the call volume. However, the measured first Ec / Io may have a lower value due to various noise components such as adjacent cells.

Meanwhile, the code domain information of the base station transmitted through the interface 310 is transmitted to the transmission power calculator 320 and the code domain signal processor 330, respectively. The transmission power calculating unit 320 calculates the total transmission power Pt. On the other hand, the code domain signal processor analyzes the transmitted code domain signal to calculate the digital gain value Pi of the power of the pilot channel. The calculated dB values of the total transmit power Pt and the pilot channel power Pp are transmitted to the pilot power calculator 340 to calculate an absolute value Ppm of the pilot power.

The absolute value of the pilot power is calculated by Equation 1 below.

The absolute value of the pilot power calculated by the pilot power calculator 340 by Equation 1 is transmitted to the abnormal state monitoring unit 380 and the second Ec / Io measuring unit 350, respectively.

As can be seen in Figure 13, since the absolute value of the pilot power should maintain a constant value when there is no abnormality, the abnormal state monitoring unit 340 monitors whether the absolute value of the pilot power is constant, and if it is not constant, the pilot of the base station It can be detected that there is an abnormality in the processing stage of the channel.

In addition, the second Ec / Io measurement unit calculates Ec / Io mathematically in consideration of the measured pilot power, the absolute value, and the transmission output. The value calculated by the second Ec / Io calculator is transmitted to the abnormal state monitoring unit 380 and compared with the value calculated by the first Ec / Io calculator.

The abnormal state monitoring unit 380 transmits the first Ec / Io calculated value, the second Ec / Io calculated value, and the absolute value of the pilot power to the display 400 to display. In addition, the abnormal state monitoring unit 380 detects an abnormal state of the base station based on the output values and transmits the abnormal state to the first to third abnormal state report units 390, 391, and 392 to notify the abnormal state.

In the present exemplary embodiment, the abnormal state report units 390, 391, and 392 are illustrated as three, but may be implemented in fewer or larger numbers as necessary.

15 is a flowchart illustrating a method for monitoring base station status according to another embodiment of the present invention.

The base station monitoring server receives and processes the code domain signal transmitted from the code domain analyzer installed in the base station (S200). In step S200, the dB value of the digital gain corresponding to the code of the transmission output power and the pilot channel is extracted from the received code domain signal.

In step S210, the absolute value of the pilot power is calculated using the value extracted in step S200. The absolute value of the calculated pilot power is used to calculate the Ec / Io of the pilot channel in step S220.

On the other hand, at the same time step (S300) receives the RF signal of the base station using a wireless terminal. The Ec / Io of the pilot channel is calculated based on the received RF signal (S310). The noise calculated for the neighboring cell or the wireless environment calculated in step S310 is considered as Ec / Io and is distinguished from the value calculated in step S230.

In step S230, the Ec / Io based on the mathematically calculated absolute value of the pilot power is compared with the threshold α. On the other hand, step 320 compares whether the Ec / Io actually measured from the wireless terminal is greater than the threshold value α. Hereinafter, a method of analyzing an abnormal state of the base station according to the result values of steps 230 and 320 will be described in detail.

First, when Ec / Io is greater than the threshold α, for example, −7 dB in step S230, it is determined whether Ec / Io measured in step 320 is greater than the threshold. Here, when the magnitude of the Ec / Io measured in steps S230 and S320 is greater than a predetermined threshold value, it is determined that there is no abnormality in the base station or call state, and the monitoring is performed after recording the measured value. End (S330).

However, when the measurement result in step S230 is different from the result of step S320, which is smaller than the threshold value α, an abnormality report of the call state is performed (S340). Because the result of step S230 is not affected by the wireless environment, when only Ec / Io measured in step S320 is smaller than the threshold value, the components of the base station are not abnormal, but due to the wireless environment such as a call state. This is because Ec / Io is degraded in the element.

Meanwhile, in step S230, when Ec / Io is smaller than the threshold α, the abnormal state monitoring unit determines whether the absolute value of the calculated pilot channel power is constant (S240). If the absolute value of the power of the pilot channel is constant in step S240, since the baseband processor of the base station is intact, it may be inferred that the degradation of Ec / Io occurred in the RF terminal of the base station. Therefore, in this case, the abnormality of the RF stage is reported in step S250.

On the other hand, if the absolute value of the pilot power is not constant in step S250, since there is an abnormality in the base band unit processing the pilot signal, the base band abnormality is reported in step S260.

On the other hand, the steps (S200, 210, 220, 230, 240, 260) may be performed independently to determine the abnormality of the pilot channel processing unit of the base station. This pilot channel can be monitored intensively at specific times or periodically monitored.

In the above-described embodiment of the present invention, in case of a problem in the transmission path for transmitting the code domain signal, the server, the switching center, the base station, and the instrument can be divided into sections and check for more. In the inspection method, it is preferable to check whether the desired data arrives correctly through a loop test in which the transmission address and the source address are identically set for each section.

In addition, in the embodiment of the present invention, the base station monitoring server is preferably installed integrally to monitor the transmission output, standing wave ratio (VSWR), reception sensitivity (RSSI) and the like together with the analysis using the code domain signal. .

Meanwhile, although the first and second embodiments of the present invention have been described separately, the common point is that the base station is monitored by analyzing the code domain signal. Therefore, the first and second embodiments of the present invention may be integrated and implemented in one monitoring server.

The base station monitoring server according to an embodiment of the present invention preferably implements a GUI system capable of displaying code domain analysis of the base station status, and may be provided in a computer-readable recording medium or implemented as a module to be integrated with the monitoring server. Can be.

According to the embodiment of the present invention described above, unlike the base station monitoring through spectrum analysis, it is possible to quantitatively analyze the transmission signal of the base station, and can accurately identify the cause of the base station abnormal state regardless of the traffic state.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

According to the configuration of the present invention described above, it is possible to quantitatively analyze the base station state for each FA regardless of the continuous transmission signal. In addition, it is possible to accurately monitor the non-linearity of the base station by accurately determining the IMD component regardless of the call volume.

In addition, according to the configuration of the present invention, it is possible to accurately determine whether the pilot channel is damaged, and by remarkably correcting the Ec / Io value measured in the wireless terminal can clearly determine where the cause of the base station abnormality occurred It is provided.

1 is a schematic diagram showing a prior art CDMA base station transmission output measurement system.

2 illustrates a remote monitoring system of a base station in the prior art.

3A and 3B show output signals for each FA output from the spectrum analyzer.

FIG. 4 is a diagram for describing an intermodulation distortion (IMD) phenomenon of a transmission signal caused by a nonlinear device.

5 is a block diagram showing a CDMA base station monitoring system according to a first embodiment of the present invention.

6 is a block diagram showing the configuration of a code domain analyzer used in the first embodiment of the present invention.

FIG. 7 is a block diagram illustrating a configuration of the code domain power measurement unit 120 illustrated in FIG. 6.

8 shows data output from an analyzer of the code domain.

9 is a block diagram showing the configuration of a monitoring server for performing IMD analysis according to the first embodiment of the present invention.

10 is a flowchart illustrating a method of performing IMD analysis according to an embodiment of the present invention.

11 is an observation diagram showing a change in output of a CDMA base station.

Fig. 12 shows components of the output of the CDMA base station at the time of no call and at the maximum call.

FIG. 13 is a graph illustrating the output of a base station output and a pilot channel over time. FIG.

14 is a block diagram showing the configuration of a base station remote monitoring server according to a second embodiment of the present invention.

15 is a flowchart illustrating a method for monitoring base station status according to a second embodiment of the present invention.

Claims (29)

In a system for monitoring a CDMA mobile communication base station, A base station state meter including a code domain analyzer mounted to a transmit antenna of the base station; A base station monitoring server connected via a network with the base station instrument, The base station monitoring server, A code domain signal processor configured to process a code domain signal providing a digital gain for each code transmitted from the base station state meter; A display unit configured to recover the code domain signal and display a digital gain for a code corresponding to each channel; A UOCN monitoring unit for monitoring noise of an unoccupied channel from the reconstructed code domain signal; Base station monitoring system including an abnormal state alarm unit for alarming the abnormal state of the base station in accordance with the output of the UOCN monitoring unit The method of claim 1, The base station monitoring server, A transmission / reception interface for receiving data transmitted from the base station instrument and performing a data transmission request to the base station instrument; A base station monitoring system further comprising a frequency selection unit for selecting a specific frequency to be monitored. The method of claim 1, And the UOCN monitoring unit monitors whether a digital gain of noise of an unoccupied channel is greater than or equal to a threshold. The method of claim 1, And the abnormal state alarm unit warns that there is an error in the transmission linearity when the digital gain of the noise of the non-occupied channel in the UOCN monitoring unit is greater than or equal to a threshold. The method of claim 1, The code domain analyzer is, A down converter for converting a transmission signal into a base band signal; An analog-digital converter for converting the converted transmission signal into a digital signal; A code domain power measurement unit measuring power for each channel of the digital-converted signal; And And a central processor to control the down converter, the analog-to-digital converter, and the code domain power measurement unit. The method of claim 5, The code domain power measurement unit, An automatic gain controller for controlling the amplitude of the digital-converted signal to be at a constant level; A DC level offset controller for adjusting a DC level offset of the digital conversion signal; A base station monitoring system comprising a CDMA synchronization unit for performing synchronization with a transmission CDMA signal. The method of claim 1, The network is a base station monitoring system implemented by E1 optical communication line. In a system for monitoring a CDMA mobile communication base station, A base station state meter including a code domain analyzer mounted to a transmit antenna of the base station; A base station monitoring server connected through the network with the base station status meter; The base station monitoring server, A transmission signal power measurement unit for measuring the power of the transmission signal transmitted from the base station state meter; A code domain signal processor for extracting a digital gain of a specific channel from a code domain signal that provides a digital gain for each code transmitted from the base station state meter; An absolute power value calculator for calculating an absolute value of the power of the specific channel from the power of the transmission signal output from the power measuring unit and the code domain signal processor and the digital gain of the specific channel; And an abnormal state monitor configured to monitor an absolute value of power of a specific channel output from the absolute power value calculator to monitor an abnormal state of the specific channel. The method of claim 8, The specific channel is a pilot channel. The method of claim 9, The base station monitoring server further includes a first abnormal state alarm unit that alerts an abnormal state when the absolute value of the power of the pilot channel monitored by the abnormal state monitoring unit is not constant. The method of claim 9, The base station monitoring server, A wireless terminal for receiving an RF transmission signal of a predetermined base station; And a first signal-to-noise ratio measurement unit for measuring a signal-to-noise ratio of a pilot channel from the wireless terminal. The method of claim 11, The base station monitoring server, And a second signal-to-noise ratio measurement unit for measuring the signal-to-noise ratio of the pilot channel from the absolute value of the pilot channel power output from the power calculator and the power of the transmission signal. The method of claim 12, And the abnormal state monitoring unit compares the first signal-to-noise ratio output from the first signal-to-noise ratio measuring unit with the second signal-to-noise ratio calculated by the second signal-to-noise ratio measuring unit. The method of claim 13, The base station monitoring server, And a second abnormal state alarm unit configured to compare the first signal to noise ratio and the second signal to noise ratio to alert an abnormal condition of a wireless environment. The method of claim 13, The base station monitoring server, And a third abnormal state alarm unit configured to alert a base station abnormal state based on the second signal to noise ratio and the value calculated by the power calculator. The method of claim 8, The code domain analyzer is, A down converter for converting a transmission signal into a base band signal; An analog-digital converter for converting the converted transmission signal into a digital signal; A code domain power measurement unit measuring power for each channel of the digital-converted signal; And The down converter, the analog-to-digital converter; And a central processor for controlling the code domain power measurement unit. The method of claim 16, The code domain power measurement unit, An automatic gain controller for controlling the amplitude of the digital-converted signal to be at a constant level; A DC level offset controller for adjusting a DC level offset of the digital conversion signal; A base station monitoring system comprising a CDMA synchronization unit for performing synchronization with a transmission CDMA signal. In the base station state measuring device for measuring the state of the CDMA mobile communication base station, A coupler connected to the transmit antenna of the base station; An interface for receiving a transmission signal of the base station from the coupler; And a code domain analyzer for calculating a digital gain for a code corresponding to a particular channel of the base station transmission signal. A method of remotely monitoring the state of a CDMA mobile communication base station, (a) selecting a specific frequency to be monitored among transmission signals of the base station; (b) receiving, via a network, a code domain signal providing a digital gain per code from an instrument connected to the base station; (c) restoring the code domain signal to indicate a digital gain for a code corresponding to a particular channel; (d) monitoring the digital gain of the unoccupied channel in the reconstructed code domain signal. The method of claim 19, The step (d), the base station monitoring method for monitoring whether the digital gain of the non-occupied channel exceeds a predetermined threshold. The method of claim 20, (e) if the digital gain of the non-occupied channel exceeds a predetermined threshold, alerting for an abnormality in transmit linearity. The method of claim 19, And displaying the reconstructed code domain signal. A method of remotely monitoring the state of a CDMA mobile communication base station, (a) selecting a specific frequency to be monitored among transmission signals of the base station; (b) receiving, via a network, code domain signals and transmit power information that provide digital gain per code from an instrument connected to the base station; (c) restoring the code domain signal to indicate a digital gain for a code corresponding to a particular channel; (d) calculating an absolute value of power of a specific channel from the transmission power information and the reconstructed code domain signal; (e) monitoring whether the calculated absolute value of power of the specific channel is constant. The method of claim 23, wherein (f) receiving an RF signal of the base station from a wireless terminal to calculate a first signal to noise ratio of the specific channel; (g) calculating a second signal-to-noise ratio of the specific channel using the calculated absolute value of the power of the specific channel; (h) monitoring the wireless environment of the base station by comparing the first signal to noise ratio with the second signal to noise ratio. The method of claim 24, (i) monitoring the state of the base station by comparing the second signal to noise ratio with a particular level. The method of claim 25, In step (i), When the second signal-to-noise ratio is smaller than a certain level and the absolute value of the power of the specific channel is constant, an alarm is detected that there is an abnormality in the RF stage of the base station And the second signal-to-noise point is less than a certain level and the absolute value of the power of the specific channel is not constant. The method according to any one of claims 23 to 26, And the specific channel is a pilot channel. In a computer-readable recording medium (a) selecting a specific frequency to be monitored among transmission signals of the CDMA mobile communication base station; (b) receiving, via a network, a code domain signal providing a digital gain for each code from an instrument connected to the base station; (c) recovering the code domain signal to indicate a digital gain for a code corresponding to a particular channel; (d) monitoring the digital gain of the unoccupied channel in the reconstructed code domain signal; The recording medium on which the containing program is recorded. In a computer-readable recording medium, (a) selecting a specific frequency to be monitored among transmission signals of the CDMA mobile communication base station; (b) receiving, via a network, code domain signals and transmit power information that provide digital gain per code from a meter connected to the base station; (c) recovering the code domain signal to indicate a digital gain for a code corresponding to a particular channel; (d) calculating an absolute value of power of a specific channel from the transmission power information and the reconstructed code domain signal; (e) comparing the calculated absolute value of a specific channel with a constant function; Record medium containing the containing program