KR20040032684A - Base station test unit - Google Patents

Abstract

PURPOSE: A BTU(Base-station Test Unit) is provided to remotely diagnose a transmission path of a mobile communication base station and a power state of each signal channel. CONSTITUTION: A mixer(300) receives a sample signal with a plurality of channels, and mixes the received sample signal with a local oscillation signal of a local oscillator(390). An ADC(Analog to Digital Converter)(310) converts an analog signal of the mixer(300) into a digital signal. A mixer(320) mixes the digital signal with inter-different phases, and outputs the mixed signals for down-converting the digital signal into a baseband signal. A filter unit(330) detects only the baseband signal outputted from the mixer(320), and generates an I(In-phase) signal and a Q(Quadrature-phase) signal. A power measuring unit(370) measures an FA(Frequency Assignment) power and a single tone power through the Q signal. An AGC(Automatic Gain Controller)(340) receives the I signal and the Q signal, and uniformly adjusts its output. A DLL(Delay Lock Loop)(350) detects a frame boundary from the signal uniformly adjusted in the AGC(340). A DSP(Digital Signal Processor)(360) stores and analyzes data of one frame obtained through the detected frame boundary. A controller(380) manages the power setup of respective channels through the output of the DSP(360) and the output of the power measuring unit(370).

Description

Base Station Diagnostic System {BASE STATION TEST UNIT}

The present invention relates to a base station diagnostic system (BTU) for diagnosing a mobile communication base station. In particular, the present invention relates to a base station diagnostic system (BTU) for remotely diagnosing a power state of each signal channel including a transmission path of a mobile communication base station. A base station diagnostic system.

As the use of mobile terminals has exploded, the demand for base stations to support the communication of mobile terminals has also increased. However, in order to optimize the performance of these base stations, it is necessary to diagnose the transmission paths of the base stations and the status of the base station antennas. Therefore, in order to diagnose the status of the base stations, a base station diagnostic system (BTU) having a terminal therein is installed remotely. Manage the base station by manual operation.

1 is a block diagram schematically illustrating a conventional base station transmission path diagnosis structure.

As shown, the base station includes a modem 100 for modulating a signal, a transceiver 110 for up-converting a signal modulated by the modem 100 to a radio frequency (RF), and a corresponding low-level RF signal. A linear power amplifier (LPA) 120 for amplifying a signal to a high level that a terminal can receive, and a front end 130 for transmitting the amplified signals connected to the antenna 140. The modem 100 and the transceiver 110 are connected to the computers 160 and 170, respectively, and are controlled remotely.

Observe the characteristics of the radio frequency (RF) of the base station having the configuration as described above to the base end diagnostic system (BTU) to the front end 130 to diagnose the path from the modem 100 to the antenna 140 Connect. For other diagnosis, a vector signal analyzer (VSA) 190 is used, which will be described later.

The basic structure of the asynchronous wireless channel access includes a dedicated physical channel for transmitting data limited to a specific mobile terminal and a common channel commonly used for the mobile terminal, and each channel is the modem. In (100), the channel is divided by the orthogonal code and the scramble process is performed by the PN code. Then, the digital signal subjected to the modulation and mapping process is upwardly adjusted to radio frequency (RF) through the transceiver 110 and then amplified by the LPA 120 and radiated through the front end 130 and the antenna 140.

The BTU 180 connected to the front end 130 includes a terminal 190 formed of a transceiver device similarly to a conventional mobile phone. After measuring the radio frequency (RF) transmission strength of the base station using the terminal 190 transmits an appropriate signal, when the base station receives the signal transmitted by the terminal 190, the signal strength is read out. The characteristics of the radio frequency can be observed and analyzed to enable the path diagnosis from the modem 100 of the base station to the antenna 140. In addition, the state of the antenna 140 may also be known by measuring the voltage standing wave ratio of the antenna 140.

That is, the BTU 180 acquires an abnormality of the configuration blocks of the base station through the path diagnosis and transmits it to the remote computers 160 and 170 connected to the base station so that the administrator can manage the path state of the base station at a remote location. do. Therefore, currently used BTU 180 was only able to diagnose the signal transmission and reception path of the base station.

If you want to check the power ratio setting for the separated channels as described above and test the base station performance while adjusting the power ratio of each channel at any base station, the vector signal analyzer (VSA) 150 as described above for the base station. To the front end 130 to measure the transmit power of the base station and the code power of each channel.

For example, when the base station manager detects an error on a path of a base station remotely through the BTU 180, the base station manager carries the VSA 150 to the base station, and connects the VSA to the front end of the base station. Check the channel power directly and adjust the channel powers to eliminate the error.

If the VSA is fixedly installed at each base station, remote measurement may be possible by incorporating the communication function of the VSA into the BTU, but since the installation of a very expensive VSA for each base station is inefficient in terms of cost, it is directly transported by an administrator in the field. The administrator will correct the errors in the base station while measuring manually.

Therefore, in order to measure the code power of the channels and the influence of the call quality on the code power ratio, the base station manager must carry the VSA 150, and the measurement through the VSA 150 must be confirmed by the base station manager. The need for telemetry is reduced. That is, in order to realize an optimal communication environment while adjusting the power ratio according to the channel rather than a simple path problem, the base station manager must carry the VSA and go directly to the base station.

As described above, since the base station diagnostic system (BTU) can identify only the problem on the communication path of the base station, to check the setting state of the power ratio for each channel in order to increase the base station efficiency, and to diagnose the wireless communication state while adjusting the same. Since it is necessary to use a vector signal analyzer (VSA), the base station administrator has to carry out the diagnosis of the base station while carrying it, and the remote control is difficult because the administrator must check the measurement result through the VSA.

In view of the above problems, the present invention not only diagnoses the communication path of the base station, but also measures the power ratio setting of each channel, diagnoses the communication state by changing the power value of the channels, and performs the above-mentioned functions remotely. It is an object of the present invention to provide a base station diagnostic system.

1 is a block diagram of a base station to which a conventional base station diagnosis system is connected.

2 is a block diagram of a base station to which the present invention base station diagnostic system is connected.

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

200: modem 210: transceiver

220: linear power amplifier 230: front end

240: antenna 250, 260: computer

270: base station diagnostic system 300: mixer

310: analog to digital converter 320: mixer

330: filter 340: automatic gain controller

350: delay locked loop 360: digital signal processor

370: power measurement unit 380: controller

The present invention for achieving the above object is a base station diagnostic system capable of remote control and path diagnosis through observation of radio frequency characteristics, after receiving a sample signal having a plurality of channels and mixing it with a local oscillation signal A signal converter converting the digital signal; A mixer / filter unit which down-converts the signal to baseband and separates the signal into an I (real channel) signal and a Q (imaginary channel) signal according to a phase difference; A power measurement unit for measuring a base station transmit power through the Q signal; An automatic gain controller that receives the I and Q signals and adjusts the output constantly; A delay lock loop for detecting a frame boundary in a signal adjusted to a constant input condition through the gain controller; A digital signal processor configured to store and analyze data of one frame obtained through the detected frame boundary; And a controller capable of observing the power setting of each channel through the output of the digital signal processor and the output of the power measurement unit.

The power measuring unit may include a measuring unit measuring a frequency allocation power and a measuring unit measuring a single tone power.

The present invention intends to add a new function of measuring channel power (channel code power) to a conventional BTU capable of remote communication and diagnosing a transmission block of a base station. It will be shown that existing functions can be applied to the functions added to the present invention while describing the embodiments of the present invention. Note that the present invention relates to a BTU applied to an asynchronous communication scheme.

In order to describe the present invention as described above, reference is made to the embodiment of FIG. 2.

As shown, the configuration of the base station consisting of the modem 200, the transceiver 210, the linear power amplifier 220, the front end 230, and the antenna 240 is the same as the conventional. The remote computers 250 and 260 shown here may be connected to the modem 200 and the transceiver 210 to transmit and receive control signals and to change communication settings of the base station. That is, the transmit / receive power values may be changed, the power ratios of the designated channel and the common channel may be newly changed, and the state of the current base station may be observed from the BTU described later.

The BTU 270 connected to the front end 230 has all of the existing functions including the terminal 400 internally, and may transmit the internal state to the remote computers 250 and 260 through the base station connection unit. The recent BTU 270 may not include a terminal therein.

The BTU 270 measures a radio frequency (RF) transmission strength of a base station through the terminal 400 or another equivalent measuring unit (not shown), and then transmits an appropriate signal, and the terminal 400 transmits an appropriate signal. When receiving the signal transmitted by the), it is possible to diagnose the path from the modem 200 of the base station to the antenna 240 by reading the signal strength. In addition, the voltage standing wave ratio of the antenna 240 is detected to determine the state of the antenna. The path and antenna diagnostic parts are well known and thus will not be described in detail.

In the present invention, a newly proposed component is added to obtain the channel power ratio setting in addition to the basic BTU function.

That is, the mixer 300 for receiving a sample signal having a plurality of channels and mixing it with the local oscillation signal 390; An analog / digital converter (310) for converting the analog output of the mixer (300) to digital; A mixer 320 for mixing the signal with a different phase and outputting the signal according to the phase to down-convert the signal to a base band; A filter unit 330 for detecting only the baseband signal of the separated output of the mixer 320 into an I signal and a Q signal; A power measurement unit 370 for measuring frequency allocation (FA) power and singleton power through the Q signal; An automatic gain controller 340 which receives the I and Q signals and adjusts the output constantly; A delay lock loop (DLL) 350 for detecting a frame boundary in a signal adjusted to a constant input condition through the gain controller; A digital signal processor (DSP) 360 for storing and analyzing data of one frame obtained through the detected frame boundary; The BTU 270 further includes a controller 380 for observing the power setting of each channel through the output of the digital signal processor 360 and the output of the power measurement unit 370.

Here, the controller 380 may be part of an existing BTU controller, and the channel power setting obtained through this may be transmitted to the remote computers 250 and 260 through the existing BTU communication line.

Let's look at the configuration in more detail.

The mixer 300 receives the transmission frequency of the sample signal of the designated channel and the common channel through the front end 230, mixes it with the output frequency of the local oscillation signal 390, and switches down.

The analog-to-digital converter 310 converts the analog output of the down-converted mixer 300 into digital.

In order to down-convert the digitally converted signal to baseband, the mixer 320 separately mixes cos and -sin with the signal, and passes the separated signals through a separate filter 330 to extract only the baseband signal. . In this case, the mixed and filtered signal with cos becomes an I signal, and the mixed and filtered signal with -sin becomes a Q signal. The I signal is the real-side channel (In-phase) from the point of view of the signal, and the Q signal is the quadrature-phase channel.

The power measuring unit 370 is connected to the controller 380 and is controlled by the controller to process the Q signal provided by the appropriate internal operation to measure the frequency assignment (Frequency Assignment) power and single-tone power, and the connected controller Forward to 380. The power measuring unit 370 may be formed of an integrated circuit such as an FPGA, and is a well-known technique that is variously used for basic power measurement.

The I and Q signals are then supplied to AGC 340, which controls the voltage between mixer 300 and analog-to-digital converter 310 to delay delay loop (DLL). Create a predetermined input condition to provide to 350.

The DLL 350 is a known part of searching for a cell in asynchronous communication, and acquires a frame boundary of a signal. Data of one frame is extracted through the obtained frame boundary, stored in the memory of the digital signal processor (DSP) 360, and the stored contents are analyzed.

Since the DSP 360 and the power measuring unit 370 are connected to the controller 380, the controller can obtain the power of each channel, thereby knowing which power ratio the channels are set to. .

Since the controller 380 may be a part of the main controller of the BTU 270, the measurement content may be delivered to a remote location by using the remote control support function of the BUT 270.

Accordingly, the above-described power measurement for each channel is possible, and by applying the BTU 270 for each base station, which further includes a function of transmitting the corresponding measurement information to a remote location, the base station manager remotely diagnoses the transmission path of the base station and for each channel. As you adjust the power value, you can immediately determine its impact.

As described above, the present invention allows the base station manager to remotely control the transmission path of the base station by remotely storing the BTU in which the base station adds a component capable of measuring channel power and remotely controlling the channel. Since the influence can be immediately determined while adjusting the power value, the base station can be diagnosed quickly and easily. In addition, since the channel power ratio can be controlled while confirming the effect, the efficiency of the base station can be increased, and the possibility of solving the problem of the base station at a remote location increases, thereby ultimately increasing communication reliability.

Claims (3)

Signal converters 300 and 310 which receive a sample signal having a plurality of channels, mix it with a local oscillation signal, and convert the sample signal into a digital signal; A mixer / filter unit 320 or 330 which down-converts the signal to baseband and separates the signal into an I (real channel) signal and a Q (imaginary channel) signal according to a phase difference; A power measuring unit 370 for measuring base station transmission power through the Q signal; An automatic gain controller 340 which receives the I and Q signals and adjusts the output constantly; A delay lock loop (DLL) 350 for detecting a frame boundary in a signal adjusted to a constant input condition through the gain controller 340; A digital signal processor (DSP) 360 for storing and analyzing data of one frame obtained through the detected frame boundary; And a controller (380) for observing the power setting of each channel through the output of the digital signal processor (360) and the output of the power measurement unit. The base station diagnostic system of claim 1, wherein the power measuring unit comprises a measuring unit measuring a frequency allocation power and a measuring unit measuring a single tone power. 2. The base station diagnostic system of claim 1, wherein the controller is capable of remotely transmitting the power settings of each measured channel.