KR20060129913A - Method and apparatus for testing state of repeater in an ofdma/tdd - Google Patents

Abstract

A repeater state testing device of an OFDMA/TDD(Orthogonal Frequency Division Multiple Access/Time Division Duplex) system and a method thereof are provided to extract spectrum information by using an FFT(Fast Fourier Transformer) from synchronous signal extraction blocks of an NMS(Network Monitoring System) module within a repeater, and to remotely service the extracted information to a network manager, so that the manager can remotely confirm spectrum information of an OFDMA/TDD signal. An NMS module frequency down-modulates an RF(Radio Frequency) signal into an IF(Intermediate Frequency) signal(201), and frequency down-modulates the IF signal into a baseband signal to output digital I(In-phase) and Q(Quadrature) signals(203). The NMS module detects symbol synchronous signals from link side input signals, and performs an FFT process for service side digital I and Q signals(205), then performs an index shifting process on the basis of a central frequency of the service side signals(207). The NMS module converts the index shifting results into an idle state to generate and store basic spectrum data(209). If a repeater state tester request is received(211), the NMS module perceives total output power of the current service side wireless signal(213), and downs basic spectrum data power as much as the perceived total power to generate substantial service side wireless signal spectrum data, then sends the generated spectrum data(215).

Description

Repeater state test apparatus and method of OPDFMA / TDD system TECHNICAL AND APPARATUS FOR TESTING STATE OF REPEATER IN AN

1 is a diagram showing the configuration of an OFDMA / TDD system to which the present invention is applied;

2 is a diagram illustrating a conventional OFDMA / TDD repeater configuration;

3 is a diagram showing the configuration of an OFDMA / TDD wireless repeater according to an embodiment of the present invention;

4 is a view showing the configuration of an NMS module according to an embodiment of the present invention;

5 is a view showing an operation flow of an NMS module according to an embodiment of the present invention;

6 illustrates a QPSK modulated signal for an OFDMA / TDD signal according to an embodiment of the present invention;

7 illustrates a fast Fourier transform result of a QPSK modulated signal for an OFDMA / TDD signal according to an embodiment of the present invention;

8 is a diagram illustrating a result of index shifting a fast Fourier transform result of a QPSK modulated signal with respect to an OFDMA / TDD signal according to an embodiment of the present invention;

9 is a diagram showing a repeater status test result screen provided to a remote manager or a field manager according to an embodiment of the present invention.

The present invention relates to an Orthogonal Frequency Division Multiple Access / Time Division Duplex (OFDMA / TDD) system, and more particularly, to an apparatus and method for monitoring a state of a wireless repeater in an OFDMA / TDD system.

1 is a diagram illustrating a general configuration of an OFDMA / TDD system including a wireless repeater. Referring to FIG. 1, an OFDMA / TDD system includes an OFDMA / TDD base station 200, an OFDMA / TDD wireless repeater (hereinafter referred to as a "relay") 100, an OFDMA / TDD terminal (hereinafter referred to as a "terminal"). (300) is made. The OFDMA / TDD base station 200 transmits a downlink signal to the repeater 100 using a radio interface. The repeater 100 receiving the base station downlink signal transmits the downlink signal to the terminal 300 using the air interface in accordance with the detected TDD synchronization signal after detecting the TDD synchronization signal. After receiving the required downlink frame, the terminal 300 transmits an uplink signal to the repeater 300. The repeater 300 receiving the uplink frame transmits the uplink signal to the OFDMA / TDD base station 200 using the air interface.

The general configuration of the repeater 100 is shown in FIG. 2 is a view showing the configuration of a conventional repeater 100. Referring to Fig. 2, the repeater 100 includes a link side antenna, a link band-pass filter (BPF) block 10, a download up / down converter 20, a switching unit 30, and a service side BPF. (Band-Pass Filter) block 40, service side antenna, reference frequency generator 50, upload up / down converter 60, NMS module 70 and a plurality of amplifiers.

The link side antenna and the link BPF block 10 transmit and receive radio signals to and from the base station 200, and the service side antenna and service side BPF block 40 transmit and receive radio signals to and from the terminal 300. do. The switching unit 30 processes the up and down signals by extracting the synchronization. The NMS module 70 includes a sync signal detector 70 and a processor 73 to manage the state of the repeater 100 in addition to extracting the sync signal, and includes an automatic gain controller (AGC) and an ALC. (Analog Sine Circuit), monitors whether the repeater module has failed. The NMS module 70 transmits NMS data indicating the status of the relay to the service provider NMS server through the TCP / IP port, or directly connects to the relay 100 through a console, USB (Universal Serial Bus), Ethernet, or the like. Is transmitted to the field test PC (80). The NMS module 70 may extract the synchronization signal in the same manner as the method of obtaining the synchronization signal from the signal received from the terminal 300.

Since the repeater 100 configured as described above aims at smooth transmission and reception of signals between the base station 200 and the terminal 300, an accurate synchronization signal must be extracted from the signal received from the base station 200 and the terminal 300. do. Therefore, a fast Fourier transformer (FFT) must be provided to correct the synchronization signal, thereby correcting the timing and frequency offset. In addition, channel estimation may be required to counteract phase changes such as reflection / scattering. Therefore, the FFT is essential for preamble and pilot signal demodulation.

Meanwhile, the OFDMA / TDD service provider must monitor the state of the plurality of repeaters 100 in the network management dimension. In the case of the repeater 100, the wireless signal is observed in a spectral form in order to find out the quality characteristics of the wireless signal. Moreover, the instrument is connected directly to the repeater 100 in the field, and the signal is coupled to analyze the network manager is not able to check the spectral information of the OFDMA / TDD signal.

It is an object of the present invention to provide a repeater state test apparatus and method of an OFDMA / TDD system that allows a network manager to remotely observe the quality of a specific repeater.

In addition, an object of the present invention is to provide an apparatus and method for testing a repeater state of an OFDMA / TDD system that can extract spectrum information from a synchronization signal extraction block of an NMS module in a repeater and provide the network manager to a network manager remotely. .

In addition, it is an object of the present invention to provide a repeater state test apparatus and method that can determine whether there is an abnormality in the wireless environment or repeater using the OFDMA / TDD spectrum without measuring the repeater in the field.

In order to achieve the above object, the present invention provides a repeater output signal state of an Orthogonal Frequency Division Multiple Access / Time Division Duplex (OFDMA / TDD) system, and in the test apparatus mounted to the repeater, the repeater may be And a radio frequency processing of the service-side radio signal to be transmitted to the OFDMA / TDD terminal and the link-side radio signal received from the OFDMA base station, and outputs a radio frequency integrated circuit (121) corresponding to each signal. In response to the first RF IC and the second RF IC, the signals output from the first RF IC and the second RF IC are in-phase (Q) and Q (Quadrature) signals for the service-side radio signal, and the A first A / D (Analog / Digital) converter, a second A / D converter, which is converted into an I, Q signal for a link-side radio signal and outputs the signal, and is connected to the second A / D converter, I, Q signal for A preamble detector for detecting and outputting a symbol synchronization signal, a first fast Fourier transformer for fast Fourier transforming and outputting an I, Q signal for the service-side radio signal according to the input symbol synchronization signal, and the fast Fourier transform Index-shifts the received service-side radio signal with respect to the center frequency, and if the fast Fourier-transformed service-side radio signal is an integer state declared as an integer, converts it to an idle state based on 0 dB and sets the basic value for the service-side radio signal. Generate and store the spectral data, and if there is a request for the repeater status test from the outside, currently measuring the output power of the service-side radio signal, down the output power of the basic spectrum data by the measured output power to the actual service side Generate wireless signal spectrum data to It characterized in that it comprises a processor for transmission to the instrument test conditions required destination.

The present invention relates to a repeater test method for an orthogonal frequency division multiple access / time division duplex (OFDMA / TDD) system, wherein the repeater receives a link-side radio signal received from an OFDMA base station and a service-side radio to be transmitted to an arbitrary OFDMA / TDD terminal. According to a first process of clipping and wirelessly processing a signal and outputting it as a digital in-phase (Q) or quadrature (Q) signal, the service is performed according to a symbol synchronization signal detected from I and Q signals for the link-side wireless signal. A second step of performing fast Fourier transform on the I / Q signal with respect to the side radio signal, a third step of indexing the fast Fourier transformed service-side radio signal based on a center frequency, and the fast Fourier transformed service-side radio Basic specifications for the service-side radio signal by converting the signal into an idle state based on 0 dB if the signal is an integer state declared as an integer. A fourth process of generating and storing rum data, and if the repeater state test request is received from the outside, the output power of the service-side radio signal is currently measured, and the output power of the basic spectrum data is reduced by the measured output power. And a fifth process of generating an actual service side wireless signal spectrum data and transmitting the same to the repeater state test request target.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the same components in the drawings are represented by the same reference numerals and symbols as much as possible even if shown in different drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

First, referring to FIG. 3, a configuration of an orthogonal frequency division multiple access / time division duplex (OFDMA / TDD) wireless repeater (hereinafter referred to as a "relayer") according to an embodiment of the present invention will be described. 3 is a diagram illustrating a configuration of an OFDMA / TDD wireless repeater according to an embodiment of the present invention. As shown in Fig. 3, the repeater includes a link side antenna, a link band-pass filter (BPF) block 10, a download up / down converter 20, a switching unit 30, and a service side BPF ( Band-Pass Filter block 40, the service antenna, the reference frequency generator 50, upload up / down converter 60, NMS module 110 and a plurality of amplifiers.

The link side antenna and the link BPF block 10 transmit and receive radio signals to and from the base station 200, and the service side antenna and service side BPF block 40 transmit and receive radio signals to and from the terminal 300. do. The switching unit 30 processes the up and down signals by extracting the synchronization.

The NMS (Network Monitoring System) module 110 manages the state of the repeater 100 in addition to the synchronization signal extraction, and monitors whether the AGC (Automatic Gain Controller), ALC (Analog Sine Circuit), or the repeater module has failed. The NMS module 110 includes a sync signal detector 111, a processor 113, a sync signal detector, and a fast Fourier transform 115 according to an embodiment of the present invention. The NMS module 100 detects a synchronization signal through the synchronization signal detector 111 by coupling a radio signal received through a link side antenna in the link BPF block 10. The NMS module 100 couples the wireless signal that is finally output through the service antenna at the service BPF block 40, and converts the signal into fast Fourier transforms to generate and store basic spectrum data of the wireless signal. The basic spectral data is a spectral form of the radio signal according to the present invention. The NMS module 100 converts the radio signal into an spectral form of an idle state regardless of the variable output power of the radio signal. . The NMS module 110 measures the output power of the radio signal output through the service antenna when requested by the field test computer 80 or the operator MNS server 90, and stores the basic spectrum data stored in advance. The output power is applied to the final spectral data to be transmitted to the field test computer 80 or the operator NMS server 90.

The configuration of the NMS module 110 as described above is shown in FIG. 4 is a diagram illustrating a configuration of an NMS module 110 according to an embodiment of the present invention. Referring to FIG. 4, the NMS module 110 includes a first RF IC 121, a first analog / digital converter 123, a second RF IC 125, A second A / D (Analog / Digital) converter 127, a first fast Fourier transformer 129, a second fast Fourier transformer 131, a preamble detector 133, a power detector 135, a processor 113, a counter 139, a timing signal generator 141, and a memory 137.

The link-side radio signal is input to the second RF IC 125 and frequency-modulated into the link-side IF signal, the link-side IF signal baseband frequency is down-modulated, and input to the second A / D converter 127 to be linked to the link-side I. It is modulated by the / Q signal and output. The link side I / Q signal output from the second A / D converter 127 is input to the second fast Fourier transformer 131, the preamble detector 133, and the power detector 135. The preamble detector 133 detects a symbol synchronization signal from an input link side I / Q signal and provides the symbol synchronization signal to the first fast Fourier transformer 129 and the second fast Fourier transformer 131. The second fast Fourier transformer 131 finds a fast Fourier transform start point of the link-side I / Q signal through the symbol synchronization signal and performs Fourier transform on the link-side I / Q signal to estimate frequency offset and estimate the channel in the processor 113. The timing offset and the frequency offset are corrected for accurate FFT calculation. The service-side radio signal is input to the first RF IC 121 and frequency-modulated into a link-side IF signal, and the base of the link-side IF signal is adjusted. The band frequency is down-modulated, and is modulated and output to the service side I / Q signal through the first A / D converter 123. In this case, the service side I / Q signal has a value of -1 to 1, but is converted into binary data in 6 to 14 bits according to the resolution of the first A / D converter 123. In an embodiment of the present invention, it is assumed that the first A / D converter 123 is 8 bits, the point of the first fast Fourier transformer 131 is 1024 points, and the modulation scheme is QPSK. Accordingly, FIG. 6 shows the service side QPSK I / Q signal of 1024 points. 6 illustrates a QPSK modulated signal for an OFDMA / TDD signal according to an embodiment of the present invention.

4, the first fast Fourier transformer 129 finds a fast Fourier transform start point of the service side I / Q signal according to a symbol synchronization signal provided from the preamble detector 133, and provides a service side I / Q signal. Fourier transform takes only a real value or an image value and outputs it to the processor 113. The service side fast Fourier transform signal output from the first fast Fourier transformer 129 is shown in FIG. 7 illustrates a fast Fourier transform result of a QPSK modulated signal for an OFDMA / TDD signal according to an embodiment of the present invention. The first fast Fourier transformer 129 inputs from the center frequency to take only a real value or an image value. FIG. 7A shows a fast Fourier transform result of an idle state by the first fast Fourier transformer 129, and FIG. 7B shows a transform result declared as an integer type of the first fast Fourier transformer 129. Indicates. In general, since a signal transmitted / received in an actual OFDMA / TDD system is integer data, a fast Fourier transform result is displayed as shown in FIG.

The processor 113 shifts an index as shown in Equation 1 based on a center frequency fc to represent a service-side Fourier transform signal input from the first fast Fourier transformer 129 in a spectral form according to the present invention. do.

That is, in the above-described embodiment of the present invention, since the point of the first fast Fourier transformer 129 is assumed to be 1024 points, the processor 113 according to Equation 1, f, that is, the fast Fourier transform point is 1; To 512, the index is shifted to 513 to 1024 by adding 512 to the fast Fourier transform point. In addition, when f, that is, the fast Fourier transform point belongs to 513 to 1024, the processor 113 subtracts 512 from the corresponding Fast Fourier transform point and index shifts from 1 to 512.

This index shift result is shown in FIG. FIG. 8 illustrates a result of index shifting a fast Fourier transform result of a QPSK modulated signal with respect to an OFDMA / TDD signal according to an embodiment of the present invention. FIG. 8 (a) shows the result of index shifting the fast Fourier transform result of the idle state by the above process, and FIG. 8 (b) shows the index shift of the fast Fourier transform result of the integer state in the same process as above. In spectral form as shown.

In general, since a signal transmitted / received in an actual OFDMA / TDD system is integer data, an index shift result of a service-side Fourier transform signal is shown in FIG. 8 (b). In other words, the fast Fourier transform result should be expressed in the dB region like the spectrum analyzer. As shown in FIG. 7 (b), the fast Fourier transform result value declared as an 8-bit integer is ambiguous on the y axis. This criterion should be displayed against the total output power of the service-side radio signal. The total output power is measured analoguely at the radio end, and the I and Q values range from -1 to 1. Therefore, the processor 113 dumps the result value into the 8-bit value in the processor 113 of the NMS module 110 and scales it to -1 to 1 value. When the scaled I and Q data are sequentially calculated by calculating Equation 2, they are expressed as shown in FIG.

y_dB = 10log10 (I (i) 2 + Q (i) 2)

At this time, the i value is the x axis, that is, the y axis, that is, the amplitude value in the graphs shown in FIGS. 6 (a) and 6 (b).

The processor 113 finally stores the service-side radio signal spectrum data of an idle state as shown in FIG. 8 (a) in the memory 137 as basic spectrum data.

Subsequently, the processor 113 measures the output power of the radio signal output through the service antenna when requested by the field test computer 80 or the operator MNS server 90, and stores the base spectrum in advance. The actual spectrum data of the final service-side radio signal to which the output power is applied to the data is transmitted to the field test computer 80 through the serial communication channel or to the operator NMS server 90 through TCP / IP.

An operation of the NMS module 110 is illustrated in FIG. 5. 5 is a diagram illustrating an operation flow of the NMS module 110 according to an embodiment of the present invention. Referring to FIG. 5, the NMS module 110 frequency-modulates an RF signal into an IF signal in step 201 and proceeds to step 203. In step 203, the NMS module 110 modulates the IF signal into baseband and outputs the digital I and Q signals, and proceeds to step 205. In step 205, the service-side digital I and Q signals are fast Fourier-converted according to the symbol synchronization signal detected from the link input signal and the detected symbol synchronization signal. In step 207, the index shift is performed as in Equation 1 on the basis of the center frequency fc of the fast Fourier-transformed signal on the service side. In step 209, the NMS module 110 converts the index shift result of the service-side fast Fourier transform signal in the integer state into an idle state using Equation 2 to generate and store basic spectrum data for the service-side radio signal.

Thereafter, in step 211, the NMS module 110 proceeds to step 213 if there is a request for a repeater condition tester from the outside. In step 213, the NMS module 110 determines the total output power of the current service side wireless signal and proceeds to step 215. In this case, the actual measurement of the total output power of the current service-side radio signal is made in the repeater 110. In step 215, the NMS module 110 downgrades the basic spectrum data power by the determined total power to generate the actual service side radio signal spectrum data of the repeater, and in step 211, the actual service side radio to the side of the repeater state tester request. Transmit signal spectrum data.

The field test computer 80 or the operator MNS server 90 having received the actual service side radio signal spectrum data displays the relay state spectrum data as shown in FIG. 9 is a diagram illustrating a repeater status test result screen provided to a remote manager or a field manager according to an embodiment of the present invention.

9, the repeater state test result screen displays the spectrum of the service-side radio signal in the idle state as a dotted line and down the spectrum of the idle state by the output power of the current service-side radio signal measured on average in a normal environment. A substantial service-side radio signal spectrum is displayed in solid lines. The full spectrum is then displayed by the center frequency and the frequency interval.

As described above, the present invention enables the network manager to check the spectrum of the radio signal transmitted from the repeater at a long distance without additional measurement equipment.

In the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

As described above, in the present invention, the NMS module of the repeater couples the radio signal that is finally output through the service antenna in the service BPF block, and generates and stores basic spectrum data of the idle state by performing fast Fourier transform of the service radio signal. When the repeater status tester requests from the field test computer or the operator's MNS server, the output power of the radio signal output through the service antenna is measured on demand, and the basic spectrum data stored in advance is lowered by the output power. By transmitting to the field test computer or operator NMS server, the network manager can check the spectral mask, which is an important radio characteristic of the OFDMA / TDD system, to find out the repeater quality, and can immediately cope with the deterioration of quality. Higher quality to users Can provide services. In addition, repeater manufacturers or after-sales service providers can easily observe the spectrum without measuring instruments, which is useful for network management.

Claims (4)

In the test apparatus for providing a repeater output signal state of an Orthogonal Frequency Division Multiple Access / Time Division Duplex (OFDMA / TDD) system, The repeater wirelessly processes and outputs a service side radio signal to be transmitted to an arbitrary OFDMA / TDD terminal and a link side radio signal received from an OFDMA base station, and outputs a first RF IC (Radio Frequency Integrated Circuit) 121 corresponding to each signal. With a second RF IC, Each signal output from the first RF IC and the second RF IC is connected in correspondence with the first RF IC and the second RF IC, and an in-phase (Q) and quadrature (Q) signal for the service-side radio signal is connected to the link. A first A / D (Analog / Digital) converter and a second A / D converter for converting and outputting an I, Q signal for a side radio signal; A preamble detector connected to the second A / D converter and detecting and outputting a symbol synchronization signal from I and Q signals for the link-side wireless signal; A first fast Fourier transformer for fast Fourier transforming and outputting an I, Q signal for the service-side radio signal according to the input symbol synchronization signal; Index-shift the fast Fourier transformed service-side radio signal based on a center frequency, and convert the fast Fourier transformed service-side radio signal to an idle state based on 0 dB if the integer is declared as an integer. Generate and store the basic spectrum data for the signal, and if there is a request for the repeater status test from the outside, the output power of the service-side radio signal is currently measured, and the output power of the basic spectrum data is reduced by the measured output power. And a processor configured to generate actual service side wireless signal spectrum data and transmit the same to the repeater state test request target. The method of claim 1, wherein the processor performs the index shift according to Equation 3 below, and if the fast Fourier transformed service-side radio signal is an integer state declared as an integer, the processor performs the index shift based on 0 dB. And converting to an idle state, wherein i is an amplitude corresponding to frequency values of I and Q signals for the service-side radio signal.

y_dB = 10log10 (I (i) 2 + Q (i) 2) The method of claim 1, wherein the relay state test request target terminal receives the actual service-side radio signal spectrum data, and measures the spectrum of the service-side radio signal in the idle state and the spectrum of the idle state in the normal environment on average. And displaying the spectrum of the actual service-side radio signal down to the output power of the current service-side radio signal, the center frequency, and the entire spectrum by the frequency interval. In the repeater test method of Orthogonal Frequency Division Multiple Access / Time Division Duplex (OFDMA / TDD) system, The repeater performs a radio processing by clipping the link-side radio signal received from the OFDMA base station and the service-side radio signal to be transmitted to an arbitrary OFDMA / TDD terminal and outputting it as a digital I (In-phase), Q (Quadrature) signal. Process, A second step of performing fast Fourier transform of the I and Q signals for the service-side radio signal according to the symbol synchronization signal detected from the I and Q signals for the link-side radio signal; A third process of index shifting the fast Fourier transformed service-side radio signal based on a center frequency; A fourth process of generating and storing basic spectrum data for the service-side radio signal by converting the fast Fourier transformed service-side radio signal to an idle state based on 0 dB if the integer state is declared as an integer; When the repeater state test request is received from the outside, current output power of the service-side radio signal is measured, and the output power of the basic spectrum data is lowered by the measured output power to generate actual service-side radio signal spectrum data. And a fifth process of transmitting to the relay state test request target.

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