JP2007104294A - Modulation signal analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a modulation signal analyzer, capable of automatically implementing normality/abnormality determination for the analysis result of an analysis item specified by an operator, and automatically investigating the cause of abnormality as well. <P>SOLUTION: The analyzer comprises a signal analyzer 6, an abnormality determination portion 11, a cause investigation sequence memory 9, an abnormality cause investigator 8, and a display control unit 12. The signal analyzer 6 performs analysis for a modulated signal on a specified analysis item or a specified measurement item. The abnormality determination portion 11 determines the normality/abnormality for the analysis result from the signal analyzer. The cause investigation sequence memory 9 stores a plurality of measurement items to be performed for the modulated signal for each analysis item, if the analysis item is determined as abnormal, and the memory 9 stores a cause investigation sequence indicative of an implementation order of normality/abnormality determination for the analysis result. The abnormality cause investigator 8 implements analysis on the measurement items, according to the cause investigation sequence of the analysis item, in response to the result of abnormality determination for the analysis item, and investigates the cause of abnormality for the analysis item. The display control unit 12 displays and outputs each analysis result, determination result, and the cause of abnormality on a display section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a modulation signal analysis apparatus that performs signal analysis of an input modulation signal, and in particular, analyzes one or a plurality of specified analysis items with respect to the modulation signal, and the analysis result is abnormal. If it occurs, the present invention relates to a modulation signal analyzing apparatus for investigating the cause of the abnormality.

  For example, in a mobile communication system including a base station and a plurality of mobile terminals that can communicate with the base station, signals transmitted from the base station to each mobile terminal are transmitted data of each channel for each mobile terminal. This is a modulated signal obtained by phase modulation.

In such a modulation signal analysis device that performs various signal analysis for obtaining various signal qualities such as modulation accuracy, frequency accuracy, and signal level in the modulation signal, for example, the digital modulation analysis device exemplified in Patent Document 1 is used. As described above, the analog modulation signal to be analyzed is converted into a digital modulation signal by an A / D converter, and a signal for a certain period in the modulation signal is stored and held in a memory. Then, signal analysis of each measurement item such as the modulation accuracy measurement, the frequency measurement, and the signal level measurement described above is performed on the modulation signal for a predetermined period stored in the memory. The analysis result of the signal analysis performed for each measurement item is stored and held in the storage unit and is displayed and output on the display unit.
Japanese Patent No. 3055085 (Japanese Patent Laid-Open No. 7-297859)

  However, the signal analysis performed for each measurement item in the above-described modulation signal analysis apparatus, for example, in the modulation accuracy (EVM) measurement, the difference between the measurement point on the measured constellation and the ideal point without error is calculated. It is what is to be obtained, and does not determine whether the obtained modulation accuracy is in a normal range or abnormal. Furthermore, it does not investigate the cause of the abnormality in the case of abnormality determination.

  Further, in the above-described modulation signal analysis apparatus, for example, in the modulation accuracy (EVM) measurement, the analysis result is displayed as a numerical value such as [%], so that information on the cause of the significant deterioration of the modulation accuracy (EVM) is obtained. When the operator of this modulation signal analysis device investigates the cause of the modulation accuracy (EVM) deterioration, for example, signal analysis of another measurement item such as constellation measurement and phase error measurement is performed. It was necessary to carry out.

  Thus, in the above-described modulation signal analyzing apparatus, when the measurement item specified by the operator is defined as the analysis item, the presence or absence of an abnormality in the analysis result for the analysis item specified by the operator is displayed on the display unit. The operator needs to judge from the analysis result. Even if it is determined that there is an abnormality, the operator who has little experience cannot easily investigate the cause of the abnormality.

  In new developments and periodic inspections of mobile terminals and base stations, it is necessary to perform signal analysis on modulated signals and investigation of the cause when an abnormality occurs in a short time. There's a problem.

  The present invention has been made in view of such circumstances, and normal / abnormal determination is automatically performed on the analysis result of the analysis item designated by the operator.At the time of abnormality determination, the cause of the abnormality is automatically investigated. Accordingly, it is an object of the present invention to provide a modulation signal analyzing apparatus that can investigate the cause of an abnormality in a short time, even for an unskilled person with little experience, and can further improve operability.

  In order to solve the above problems, the present invention provides a modulation signal analyzing apparatus for analyzing an input modulation signal, a waveform memory for storing the input modulation signal, and a designation for the modulation signal stored in the waveform memory. Each analysis item that analyzes the specified analysis item or specified measurement item and outputs an analysis result, an abnormality determination unit that determines whether the analysis result output from the signal analysis unit is normal or abnormal, and outputs the determination result, and each analysis For each item, investigate the cause that indicates the order in which multiple measurement items for the modulation signal to be implemented to determine the cause of the abnormality when the analysis result of the analysis item is determined to be abnormal, and the normal / abnormal determination of the analysis result The cause investigation sequence memory that stores the sequence and the cause investigation sequence memory upon receipt of the judgment result indicating the abnormality of the analysis item output from the abnormality judgment unit According to the stored cause investigation sequence of the corresponding analysis item, the signal analysis unit is designated for each measurement item, the analysis of the measurement item is performed, and an abnormality cause investigation unit that investigates the cause of abnormality of the corresponding analysis item, and a signal A display control unit for displaying on the display unit each analysis result output from the analysis unit, a determination result output from the abnormality determination unit, and an abnormality cause of the analysis item investigated by the abnormality cause investigation unit;

  In the modulation signal analyzing apparatus configured as described above, the cause investigation sequence memory includes a plurality of measurement items to be performed to investigate the cause of abnormality when the analysis result of the analysis item is determined to be abnormal, and the analysis thereof. The execution order of the normality / abnormality determination as a result is stored.

  Then, when the operator designates, for example, one or a plurality of measurement items that can be analyzed by the signal analysis unit of the modulation signal analysis device as the analysis item, the signal analysis unit performs the corresponding analysis on each analysis item. Analysis is performed. A normal / abnormal determination of the analysis result for the analysis item is performed by the abnormality determination unit, and the determination result is sent to the abnormality cause investigation unit. When receiving the determination result indicating the abnormality of the analysis item, the abnormality cause investigation unit investigates the cause of abnormality of the corresponding analysis item according to the cause investigation sequence of the analysis item stored in the cause investigation sequence memory. In this case, each measurement item specified in the cause investigation sequence memory is performed by the signal analysis unit.

  Therefore, normal / abnormal determination is automatically performed on the analysis result for the analysis item designated by the operator, and the cause of the abnormality is automatically determined when the abnormality is determined.

  Further, according to another invention, the abnormality determination unit in the modulation signal analyzing apparatus according to the above-described invention is configured such that when the analysis result of the analysis item output from the signal analysis unit indicates abnormality, the abnormality of the analysis item is indicated to the display control unit. Instructs the display to prompt execution of the cause investigation execution instruction, and outputs the judgment result indicating that the analysis result of the analysis item for the abnormality cause investigation section indicates an abnormality only when the instruction to execute the cause investigation execution of the analysis item is input. To do.

  In the modulation signal analyzing apparatus configured as described above, when an abnormality occurs in the analysis result of the specified analysis item, a word or an icon prompting execution of instruction input for the abnormality determination result and abnormality cause investigation execution is displayed on the display unit. Is displayed. Only when the operator inputs an instruction to perform abnormality cause investigation, investigation of the cause of abnormality of the analysis item is performed.

  Therefore, even if an abnormality occurs in the analysis result, it is not necessary for the operator to investigate the cause of the abnormality when the cause of the abnormality is clear. Is possible.

  Furthermore, in another invention, each cause investigation sequence in the modulation signal analysis apparatus of the above-described invention has two or more measurement items with priorities, and causes the signal analysis unit to execute each measurement item, The abnormality determination unit sequentially executes the normal / abnormal determination of the analysis result of each measurement item according to the priority order, and when the first determination is made abnormal, the analysis result of each measurement item of the priority order lower than that measurement item The normal / abnormal determination is stopped, and the abnormality of the measurement item first determined to be abnormal is set as the cause of the analysis item abnormality.

  In the modulation signal analyzing apparatus configured as described above, the normal / abnormal determination of each measurement item is performed in the descending order of the possibility that the analysis result of the measurement item specified in the cause investigation sequence is the cause of abnormality of the analysis item. Therefore, the cause of the abnormality of the analysis item is determined at a relatively early stage, so that the cause of the abnormality can be determined in a shorter time.

  In the present invention, the normal / abnormal determination of the analysis result for the analysis item designated by the operator is performed, and when the abnormality is determined, the cause of abnormality of the corresponding analysis item is determined according to the cause investigation sequence.

  Therefore, the normal / abnormal judgment of the analysis results for the analysis items and the investigation of the cause of the abnormality at the time of abnormality are automatically performed, so that even an unskilled person with little experience can make an abnormality in a short time just like an expert. The cause can be investigated and the operability can be further improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a modulation signal analyzing apparatus according to the first embodiment of the present invention.

  The modulation signal a to be analyzed input to the modulation signal analyzing apparatus of the first embodiment is obtained by phase-modulating transmission data of each channel for each mobile terminal transmitted from the base station to each mobile terminal as described above. This is a modulation signal of the W-CDMA standard.

  The modulated signal a has a transmission format shown in FIG. For example, one frame 1 having a time width of 10 ms is composed of 15 slots 2. In each slot 2, the transmission data 3 that is phase-modulated and code-spreaded to the full length of the slot 2, and an SCH (Synchronization Channel) 4 that is added to the transmission data 3 at the head position of the slot 2, Is provided. This SCH 4 is a physical downlink channel used for cell search (time search), and is provided to synchronize each slot 2.

  In FIG. 1, a signal of at least one frame and one minute (10 ms) in the input modulation signal a is stored in the waveform memory 5. The signal analysis unit 6 performs signal analysis of the analysis item designated by the operator on the operation unit 7 such as a keyboard with respect to the modulation signal a stored in the waveform memory 5 and an abnormality cause investigation unit The signal analysis of a plurality of measurement items designated by the cause investigation sequence of the analysis items stored in the cause investigation sequence memory 9 from 8 is performed. The analysis item indicates a measurement item designated by the operator among all measurement items that can be analyzed (measured) by the signal analysis unit 6 of the modulation signal analyzing apparatus.

  The signal analysis unit 6 writes the analysis items and analysis results of each measurement item to the signal analysis result memory 10 and sends them to the abnormality determination unit 11. The display control unit 12 displays and outputs the analysis items written in the signal analysis result memory 10 and the analysis results of each measurement item on the display unit 13.

  A specified value memory 14 is provided inside the abnormality determination unit 11. In the specified value memory 14, an allowable range for analysis results of all measurement items including analysis items that can be analyzed by the signal analysis unit 6 is stored. In this embodiment, as measurement items, modulation accuracy (EVM) calculation, phase error calculation, constellation calculation, code domain power measurement, SCH detection, transmission power (input level) measurement, RACH (random access channel) power measurement, Frequency (carrier frequency) measurement, adjacent channel leakage power measurement, spurious component measurement, I and Q level measurement, modulation method determination, and the like can be performed.

  The abnormality determination unit 11 is normal when the analysis item input from the signal analysis unit 6 and the analysis result of each measurement item are within the allowable range of the corresponding measurement item (analysis item) stored in the specified value memory 14. If the measurement item (analysis item) is outside the allowable range, it is determined as abnormal. The abnormality determination unit 11 sends the normal / abnormal determination result to the display control unit 12 and to the abnormality cause investigation unit 8. Further, the abnormality determination unit 11 writes a normal / abnormal determination result in the signal analysis result memory 10.

  The cause investigation sequence memory 9 stores a plurality of cause investigation sequences corresponding to each analysis item for investigating the cause of abnormality when the analysis result of each analysis item is determined to be abnormal. Each cause investigation sequence has two or more measurement items with priorities, causes the signal analysis unit 6 to execute each measurement item, and causes the abnormality determination unit 11 to normalize the analysis result of each measurement item. Abnormality determination is executed sequentially according to the priority order. When it is first determined as abnormal, the normal / abnormal determination of the analysis result of each measurement item with a priority lower than the measurement item is stopped, and this abnormality is determined first. This is a program format describing the procedure for causing an abnormality in a measurement item to cause an abnormality in an analysis item.

  6 and 7 show the cause investigation sequence of the analysis item for calculating the modulation accuracy (EVM). Transmission power (input level) measurement, frequency measurement, SCH detection, pilot detection, EVM time characteristic measurement, code domain power measurement to investigate the cause when the analysis result of modulation accuracy (EVM) calculation is determined to be abnormal A plurality of measurement items such as phase error calculation and constellation calculation are set. In S (step) 1 to S (step) 8, the order in which the abnormality determination unit 11 performs the normal / abnormal determination of the analysis result of each measurement item described above is described.

  In this example, when the modulation accuracy (EVM) is abnormal beyond the allowable range, the transmission power (input level) of the modulated signal a after frequency conversion and removal of frequency components other than the designated frequency band by a bandpass filter are performed. Therefore, first, in S1, the measurement value of the input level (transmission power measurement) is determined. When the input level is less than or equal to the allowable value, it is determined that the frequency specified by the standard and the frequency of the modulation signal a are different from each other, and that the modulation accuracy (EVM) exceeds the allowable range. As shown in FIG. 14B, the frequency domain display of the entire band (250 MHz) is performed. In this case, since the cause of the abnormality has been determined in S (step) 1, the normal / abnormal determination of the analysis result of each measurement item of the lower priority order after S (step) 2 is stopped.

  If the input level is normal in S1, the process proceeds to S2.

  As described above, from S1 to S8, the normal / abnormal determination of the analysis result of each measurement item is sequentially executed according to the priority order, and the first abnormality is set as the cause of abnormality of the analysis item. If no abnormality is detected in the last S8, it is determined in S9 that the cause of the abnormality of the analysis item is unknown and a message to that effect is displayed.

  FIG. 8 shows a cause investigation sequence of analysis items of RACH (random access channel) transmission power measurement. Transmission power (input level) measurement, frequency measurement, RACH transmission power time characteristic measurement, modulation accuracy (EVM) calculation, I and Q level time characteristic measurement to investigate the cause when the analysis result is determined to be abnormal A plurality of measurement items such as are set. In addition, Q (step) 1 to Q (step) 6 describe the order in which the abnormality determination unit 11 performs the normal / abnormal determination of the analysis result of each measurement item described above.

  Upon receiving the determination result indicating the abnormality of the analysis item output from the abnormality determination unit 11, the abnormality cause investigation unit 8 sends the signal analysis unit 6 the signal analysis unit 6 according to the cause investigation sequence of the analysis item stored in the cause investigation sequence memory 9. By specifying each measurement item and performing analysis of the measurement item, the abnormality determination unit 11 determines the normal / abnormality of the analysis result of each measurement item in order according to the priority order, thereby determining the cause of abnormality of the corresponding analysis item. Investigate. The abnormality cause investigation unit 8 writes the cause of abnormality in the analysis result of the analysis item in the cause investigation result memory 15 when an abnormality occurs.

  The display control unit 12 displays each analysis result stored in the signal analysis result memory 10, the determination result output from the abnormality determination unit 11, and the cause of abnormality of the analysis item stored in the cause investigation result memory 15 on the display unit 13. Output.

  FIG. 3 is a block diagram showing a specific configuration of the signal analyzing unit 6 in the modulation signal analyzing apparatus according to the first embodiment of FIG.

  The high-frequency modulation signal a having the transmission format shown in FIG. 2 input from the input terminal 16 of the modulation signal analyzer is frequency-converted to an intermediate frequency based on the frequency signal from the local oscillator (LOOSC) 18 by the frequency converter 17. After that, unnecessary frequency components are removed by a bandpass filter (not shown), converted into a digital modulation signal a by the A / D converter 19, and written into the waveform memory 5. As a result, as described above, a signal of at least one frame and one minute (10 ms) in the input modulation signal a is written in the waveform memory 5.

  The digital modulation signal a for one frame (10 ms) read from the waveform memory 5 is an I / Q separation unit 20, a frame detection unit 21, an SCH detection unit 22, a transmission power measurement unit 23, and a frequency measurement unit 24. , Input to the FFT conversion unit 25.

  The frame detection unit 21 detects the start position of the frame 1 in the modulation signal a, and sends a frame synchronization signal to the I / Q separation unit 20 and the SCH detection unit 22. The SCH detection unit 22 detects the SCH 4 added to the transmission data 3 at the head position of each slot 2 of the frame 1 using the frame synchronization signal, and writes it to the signal analysis result memory 10. The transmission power measuring unit 23 measures the transmission power (input signal level) of the input modulation signal a and writes it into the signal analysis result memory 10. The frequency measuring unit 24 measures the frequency (carrier frequency) of the input modulation signal a and writes it into the signal analysis result memory 10.

The FFT conversion unit 25 performs fast Fourier transform on the input modulation signal a and writes it as a modulation signal (frequency characteristic) a _{1 in} the frequency axis domain to the signal analysis result memory 10, as well as the adjacent channel leakage power measurement unit 26 and spurious. Send to measurement unit 27.

The adjacent channel leakage power measurement unit 26 calculates the adjacent channel leakage power of the modulation signal a from the modulation signal a ₁ that is the frequency characteristic of the modulation signal a, and writes it to the signal analysis result memory 10. Furthermore, the spurious measurement unit 27 calculates a spurious component of the modulation signal a from the modulation signal a ₁ that is the frequency characteristic of the modulation signal a, and writes the spurious component into the signal analysis result memory 10.

  Note that the SCH detection unit 22 detects SCH4 only once in the digital modulation signal a for 1 frame 1 minute (10 ms), but the transmission power, frequency, adjacent channel leakage power, and spurious components are 1 frame 1 minute ( 10 ms) for each time position (elapsed time from the start time of frame 1) of the modulation signal a.

  Based on the frame synchronization signal, the I and Q separation unit 20 separates the digital modulation signal a for one frame (10 ms) into I (in-phase component) symbol data and Q (quadrature component) symbol data for each symbol unit. Then, the data is sent to the despreading unit 28 and the I and Q level measuring unit 29. The I and Q level measuring unit 29 measures the level values of the I symbol data and the Q symbol data at each symbol position indicating each elapsed time from the start time of the frame 1 in the modulated signal a, and outputs the signal as the I and Q levels. Write to the analysis result memory 10.

  The despreading unit 28 despreads the input I and Q symbol data with each spreading code used at the time of transmission to obtain I and Q symbol data for each channel. The despreading unit 28 sends the despread I and Q symbol data for each channel to the demodulation unit 30, the constellation calculation unit 31, the RACH transmission power measurement unit 32, and the code domain power measurement unit 33.

  The RACH transmission power measurement unit 32 calculates the transmission power (signal level) for each channel from the input I and Q symbol data of each channel at each symbol position, and writes it to the signal analysis result memory 10.

  The code domain power measurement unit 33 calculates the power (code domain power) of I and Q symbol data (code domain power) of each channel at each input symbol position and writes it to the signal analysis result memory 10.

  For example, as shown in FIGS. 13A and 13B, the constellation calculation unit 31 displays the input I and Q symbol data of each channel at each symbol position as measurement points 35 on the IQ coordinates. The constellation 34 is calculated and written into the signal analysis result memory 10. Further, the constellation calculation unit 31 sends the calculated constellation 34 to the modulation scheme determination unit 36, the modulation accuracy (EVM) calculation unit 37, and the phase error calculation unit 38.

  The modulation scheme determination unit 36 determines the modulation scheme of the input modulation signal a from the pattern of the measurement points 35 of the constellation 34 at the plurality of input symbol positions. Specifically, the modulation scheme corresponding to the constellation 34 calculated from a plurality of predetermined modulation schemes such as BPSK, QPSK, and 16QAM is determined. The modulation method determination unit 36 writes the determined modulation method into the signal analysis result memory 10 and sends it to the demodulation unit 30, the modulation accuracy (EVM) calculation unit 37, and the phase error calculation unit 38.

  The demodulator 30 demodulates the input I and Q symbol data of each channel at each symbol position by a demodulation method corresponding to the determined modulation method, and obtains data corresponding to the transmission data for each channel. The signal analysis result memory 10 is written.

  The modulation accuracy (EVM) calculation unit 37 is a magnitude (EVM) of an error vector from the ideal point in the determined modulation method of the measurement point 35 in the constellation 34 of each symbol position input from the constellation calculation unit 31. Is calculated and written to the signal analysis result memory 10.

  The phase error calculation unit 38 calculates the angular position on the IQ coordinate of the measurement point 35 in the constellation 34 at each symbol position input from the constellation calculation unit 31 from the angular position of the ideal point in the determined modulation method. A phase error φ indicating the angle error is calculated. Then, the calculated phase error φ at each symbol position is written into the signal analysis result memory 10.

In the signal analysis result memory 10, as shown in FIG. 4, ₁ of each channel CH ₁ , CH ₂ ,..., CH _n in the modulation signal a obtained by each measurement unit and each calculation unit of the signal analysis unit 6. An analysis result 39 for each measurement item at each time position (each symbol position) 1 to n in the frame and a normal / abnormal determination result 40 input from the abnormality determination unit 11 are written. When writing of the analysis result 39 and the determination result 40 at all time positions (each symbol position) 1 to n in one frame is completed, the average value 41 of the analysis result 39 and the determination result 40 for the average value 41 are written. It is.

  Note that SCH detection is performed only once in one frame (10 ms), and the transmission power measurement is a value before separation into each channel. Further, there is only one modulation method for the modulation signal a.

  The overall operation of the modulation signal analyzing apparatus of the first embodiment having such a configuration will be described with reference to the flowchart of FIG.

  When the modulation signal a to be analyzed is input to the input terminal 16 (R1), the modulation signal a is frequency-converted, unnecessary frequency components are removed by a BPS (band pass filter), and the A / D converter 19 performs digital conversion. The signal is converted into a modulation signal a and written in the waveform memory 5 (R2). When one or a plurality of analysis items are designated from the operation unit 7 (R3), the signals of the designated analysis items with respect to the modulation signal a for one frame (10 ms) written in the waveform memory 5 The analysis is executed (R4). Then, each analysis result for the modulation signal a for one frame (10 ms) is written into the signal analysis result memory 10 (R5). Then, the analysis result of each designated analysis item is displayed and output on the display unit 13. At the same time, the abnormality determination unit 11 also displays the determination result of normal / abnormal determination of each corresponding analysis result. In order to avoid complication, an error is displayed only in the case of abnormality determination (R6).

  For example, FIG. 9 shows an analysis result 41 and an abnormality determination error (error) 42 when the modulation accuracy (EVM) is designated as an analysis item and displayed on the display unit 13.

  FIG. 11 shows an I component characteristic 43a and a Q component characteristic 43b as analysis results when the code domain power is designated as an analysis item and displayed on the display unit 13. In the example of FIG. 11, the I component characteristic 43a and the Q component characteristic 43b are normal determination results. On the other hand, FIG. 12 shows the I component characteristic 43a and the Q component characteristic 43b determined to be abnormal.

  In R7 of FIG. 5, if there is no abnormality determination result in each analysis result of each analysis item, the signal analysis processing for the current modulation signal a is terminated. If there is an abnormality determination result in each analysis result of each analysis item, the abnormality cause investigating unit 8 reads a cause investigation sequence corresponding to one analysis item of one abnormality determination result from the cause investigation sequence memory 9 (R8). ).

  Then, based on the read cause investigation sequence, the cause investigation process of the analysis result abnormality of the analysis item is executed (R9). Specifically, for example, as described above, the analysis item is modulation accuracy (EVM) calculation, and the analysis result is shown in FIG. 9, and in the case of abnormality determination, the modulation shown in FIG. 6 and FIG. Perform the accuracy (EVM) abnormality cause investigation process. When the analysis item is RACH transmission power measurement and the analysis result is an abnormality determination, the RACH transmission power abnormality cause investigation process shown in FIG. 8 is performed.

The cause investigation result of the analysis result abnormality of the analysis item is written in the cause investigation result memory 15 (R10), and then the cause investigation result of the abnormality is displayed on the display unit 13 (R11). For example, as shown in FIG. 14A, when the analysis item is constellation calculation, the analysis result is an abnormality (error) 42, and the cause of the abnormality is “frequency shift”, FIG. As shown, the cause 44 of the abnormality is displayed. In this case, the frequency characteristic (modulation signal a _{1 in the} frequency domain) of the modulation signal a to be analyzed that is the basis for specifying the cause and the ideal signal frequency range r ₁ without “frequency deviation” are also displayed.

  When the abnormality cause investigation process for the specified analysis item is completed in R11 of FIG. 5, if an abnormality result for which the abnormality cause investigation has not been performed remains in the designated analysis item (R12), S8 Returning to step S8, the cause investigation sequence corresponding to the analysis item of the abnormality determination result for which the cause investigation of one abnormality cause has not been performed is read from the cause investigation sequence memory 9 (R8).

  If there is no abnormality result for which the cause of abnormality has not been investigated (R12), the signal analysis processing for the current modulation signal a is terminated.

  The characteristics of the modulation signal analyzing apparatus of the first embodiment configured as described above will be described with reference to FIGS. FIG. 9 shows a state where the analysis item is modulation accuracy (EVM) calculation and the analysis result 41 is abnormal (error) 42 as described above. In order to investigate the cause of this abnormality, the cause investigation sequence shown in FIGS. 6 and 7 is executed.

As described above, the signal analysis of each measurement item shown in the cause investigation sequence is performed, and first, in (S1), the measured transmission power (input level) of the transmission power (input level) measurement is allowed to be defined ( xdBm) or less, it is determined that the deviation between the frequency specified in the standard and the frequency of the modulation signal a is the cause of the abnormality in which the modulation accuracy (EVM) exceeds the allowable range. As shown in b), the frequency characteristic (modulation signal a _{1 in the} frequency domain) of the entire band (250 MHz) and the frequency characteristic r _{1 of the} ideal signal without “frequency shift” are also displayed. In this case, since the cause of the abnormality has been determined in S (step) 1, the normal / abnormal determination of the analysis result of each measurement item of the lower priority order after S (step) 2 is stopped.

  If no abnormality is detected in S1, the modulation accuracy (EVM) indicates that the input modulation signal a is not a W-CDMA standard modulation signal in S2 if the input level is abnormal in S2. Is determined to be the cause of the abnormality exceeding the allowable range, and the signal for one frame (10 ms) of the input modulation signal a is displayed on the time axis.

Furthermore, if no abnormality is detected in S2, the frequency (carrier frequency) measured by the frequency measurement unit 24 is input in S3 if it deviates from the specified frequency determined by the standard by an allowable frequency yHz or more. If the modulation signal a is not a modulation signal of the W-CDMA standard, or if the frequency is greatly shifted, it is determined that the modulation accuracy (EVM) exceeds the allowable range, and as shown in FIG. In addition, the frequency characteristic (frequency domain modulation signal a ₁ ) of 25 MHz (pass frequency bandwidth of this modulation signal analyzing apparatus) obtained from the FFT conversion unit 25 and the frequency characteristic r ₁ of the ideal signal without “frequency deviation” are obtained. indicate. Moreover, the cause 44 of abnormality is displayed.

  If the SCH and pilot (Pilot) are detected normally in S4 and S5, and the modulation accuracy (EVM) value (analysis result) determined to be abnormal in S6 is temporally fluctuating, It is determined that the abnormality of the frequency signal from the (carrier wave) or the local oscillator (LOOSC) 18 is the cause of the abnormality in which the modulation accuracy (EVM) exceeds the allowable range, and as shown in FIGS. 10 (a) and 10 (b) The EVM time characteristic 45 indicating the modulation accuracy (EVM) at each time position (symbol position) of one frame (10 ms) stored in the analysis result memory 10 is displayed and output on the display unit 13. Further, as shown in FIG. 10C, a phase error time characteristic 46 indicating the phase error φ at each time position (symbol position) of one frame (10 ms) stored in the signal analysis result memory 10 is displayed on the display unit. 13 is displayed and output.

  That is, when the EVM time characteristic 45 of FIG. 10A is obtained, it can be determined that noise is mixed in the frequency signal from the baseband (carrier wave) or the local oscillator (LOOSC) 18. Further, when the EVM time characteristic 45 of FIG. 10B is obtained, it can be determined that the jitter or the fixed phase error φ is in the carrier wave or the frequency signal. Therefore, as shown in FIG. 10C, the phase error time characteristic 46 indicating the phase error φ at each time position (symbol position) of one frame (10 ms) stored in the signal analysis result memory 10 is displayed on the display unit. 13 is displayed and output. As shown in FIG. 10C, when the phase error time characteristic 46 changes linearly, the frequency (carrier frequency) of the modulation signal a is shifted from the reference frequency defined by the standard by a certain frequency. Indicates.

  Furthermore, in S6, if the I component characteristic 43a and the Q component characteristic 43b as an analysis result of the code domain power equal to or greater than the spreading factor (SF / 2) are abnormal as shown in FIG. The phase and amplitude balance is determined to be poor, and the constellation 34 is read from the signal analysis result memory 10 and displayed on the display unit 13 as shown in FIG.

  That is, when the abnormal occurrence I component characteristic 43a and Q component characteristic 43b shown in FIG. 12 and the normal I component characteristic 43a and Q component characteristic 43b shown in FIG. 11 are compared, the abnormality occurrence points 47a and 47b can be confirmed. The detailed cause of the abnormality is unknown. However, by displaying the constellation 34 shown in FIG. 13 (b), each measurement point 35 fluctuates without staying at one point as compared to the normal constellation 34 shown in FIG. 13 (a). Therefore, it can be confirmed that it is jitter (fluctuation) of the clock (frequency). That is, in this case, the cause of the abnormality in which the modulation accuracy exceeds the allowable range is jitter (fluctuation) of the clock (frequency).

  If no abnormality is detected in S7 and no abnormality is detected in S8, the cause is unknown in S9.

  When the specified analysis item indicates the RACH transmission power measurement and the RACH transmission power indicates an abnormality, the cause investigation is performed according to the RACH transmission power abnormality cause investigation sequence shown in FIG.

  As described above, in the modulation signal analyzing apparatus according to the first embodiment, the cause investigation sequence memory 9 includes a plurality of measurement items to be executed in order to investigate the cause of abnormality when the analysis result of each analysis item is abnormal. The execution order of the normal / abnormal judgment of the analysis result is stored.

  When the operator designates an analysis item from the operation unit 7, the signal analysis unit 6 analyzes the analysis item. If the analysis result is abnormal, the analysis item is analyzed according to the cause investigation sequence of the analysis item. Abnormal cause investigation is automatically performed. Furthermore, in the cause investigation sequence, as shown in FIGS. 6, 7, and 8, the normal / abnormal judgment of each measurement item is performed in the order of the high possibility of being the cause of abnormality, and after that, the cause is investigated. The normal / abnormal judgment of is canceled. Therefore, the cause of the abnormality of the analysis item is determined at a relatively early stage, so that the cause of the abnormality can be determined in a shorter time.

(Second Embodiment)
FIG. 15 is a block diagram showing a schematic configuration of a modulation signal analyzing apparatus according to the second embodiment of the present invention. The same reference numerals as those of the modulation signal analyzing apparatus according to the first embodiment shown in FIG. Therefore, the detailed description of the overlapping part is omitted.

  In the abnormality determination unit 11a incorporated in the modulation signal analyzing apparatus of the second embodiment, a investigation instruction receiving unit 48 is provided in addition to the specified value memory 14 described above. The abnormality determination unit 11a stores the analysis items input from the signal analysis unit 6 and the analysis results of the respective measurement items in the specified value memory 14 in the same manner as the abnormality determination unit 11 in the first embodiment of FIG. If the measurement item (analysis item) is within the allowable range, it is determined to be normal, and if the measurement item (analysis item) is outside the allowable range, it is determined to be abnormal. The abnormality determination unit 11 sends the determination result of normal abnormality to the display control unit 12 and writes the determination result of normal abnormality to the signal analysis result memory 10. Therefore, the analysis result and the normal / abnormal determination result are displayed on the display unit 13 at this time.

  Further, when the analysis result of the analysis item indicates an abnormality, the investigation instruction receiving unit 48 in the abnormality determination unit 11a prompts the display control unit 12 to execute the instruction input execution of the abnormality cause investigation execution of the analysis item to the display unit 13. Or the display of the icon is instructed. Only when an abnormality cause investigation execution instruction for the analysis item is input from the operation unit 7, a determination result indicating that the analysis result of the analysis item for the abnormality cause investigation unit 8 indicates abnormality is output. Further, the investigation instruction receiving unit 48 in the abnormality determination unit 11 a performs display control of the cause of the abnormality investigated based on an instruction from the operator via the operation unit 7.

  A specific operation will be described with reference to FIGS. FIG. 16A shows a state where a constellation 34 as an analysis result when the constellation measurement is designated as an analysis item is displayed on the display unit 13. Since this analysis result is abnormal, an abnormality (error) 42 is displayed. Subsequently, as shown in FIG. 16B, a “Help” key 49 is displayed as a character or icon that prompts the execution of an instruction to execute the cause investigation.

When the operator inputs and designates the “Help” key 49 on the operation unit 7, the determination result indicating that the analysis result of the analysis item is abnormal is output to the abnormality cause investigation unit 8. As a result, the measurement item and content (cause of abnormality) 50 executed by the abnormality cause investigation unit 8 are displayed on the display unit 13 as shown in FIG. At the same time, a selection guide 51 for a display switching instruction is displayed. When the operator selects the switching instruction, as shown in FIG. 16D, there is no frequency characteristic (frequency domain modulation signal a ₁ ) and “frequency shift” of the entire band (250 MHz), which is the analysis result of the measurement item. The frequency characteristic r _{1 of the} ideal signal is also displayed.

  In FIG. 16C, if the operator does not select the switching instruction, as shown in FIG. 16E, the constellation 34 and the abnormality (error) 42, which are the analysis results of FIG. 16A, are displayed. Return to.

  The overall operation of the modulation signal analyzing apparatus of the second embodiment having such a configuration will be described with reference to the flowchart of FIG. The same parts as those in the flowchart of the modulation signal analyzing apparatus according to the first embodiment shown in FIG. 5 are denoted by the same reference numerals, and detailed description of the overlapping parts is omitted.

  When the modulation signal a to be analyzed is input to the input terminal 16 (R1), the modulation signal a is written into the waveform memory 5 (R2). When an analysis item is designated from the operation unit 7 (R3), signal analysis of each analysis item is performed on the modulation signal a written in the waveform memory 5 (R4). Each analysis result for the modulation signal a is written into the signal analysis result memory 10 (R5). The analysis result of each analysis item is displayed and output on the display unit 13. At the same time, the determination result of normal / abnormal determination of each corresponding analysis result is also displayed by the abnormality determination unit 11a (R6).

  If there is an abnormality determination result in each analysis result of each analysis item (R7), as shown in FIG. 16B, a “Help” key 49 is displayed (P2). When the “Help” key 49 is operated by the operator (P2), the abnormality cause investigating unit 8 reads the cause investigation sequence corresponding to the analysis item of the abnormality determination result from the cause investigation sequence memory 9 (R8). The cause investigation process of the analysis result abnormality of the analysis item is executed (R9). The cause investigation result of the analysis result abnormality of the analysis item is written in the cause investigation result memory 15 (R10), and then the cause investigation result of the abnormality is displayed on the display unit 13 (R11). In this case, as shown in FIGS. 16C and 16D, the display switching instruction selection guide 51 is displayed, and only when the operator selects the switching instruction, the cause investigation result of the abnormality is displayed on the display unit. 13 is displayed.

  If there is an abnormal result that has not been investigated for the cause of abnormality in the specified analysis item (R12), the process returns to S8, and one abnormality cause corresponds to the analysis item of the abnormality determination result that has not been performed. The cause investigation sequence is read from the cause investigation sequence memory 9 (R8).

  If there is no abnormality result for which the cause of abnormality has not been investigated (R12), the signal analysis processing for the current modulation signal a is terminated.

  The modulation signal analysis apparatus according to the second embodiment configured as described above can achieve substantially the same operational effects as the modulation signal analysis apparatus according to the first embodiment described above.

  Furthermore, in the modulation signal analyzing apparatus according to the second embodiment, as an operator, even when an abnormality occurs in the analysis result for the designated analysis item, if the cause of the abnormality is clear as the operator, the cause of the abnormality Since it is not necessary to carry out the investigation, it is possible to improve the signal analysis processing efficiency for the modulation signal a.

1 is a block diagram showing a schematic configuration of a modulation signal analyzing apparatus according to a first embodiment of the present invention. Frame structure diagram of modulated signal for signal analysis The block diagram which shows the detailed structure of the signal analysis part incorporated in the modulation signal analysis apparatus of the embodiment The figure which shows the memory content of the signal analysis memory incorporated in the modulation signal analysis apparatus of the embodiment Flow chart showing the overall operation of the modulation signal analyzing apparatus of the same embodiment The figure which shows the cause investigation sequence of the modulation accuracy abnormality incorporated in the modulation signal analyzer of the embodiment The figure which shows the cause investigation sequence of the modulation accuracy abnormality similarly incorporated in the modulation signal analyzer of the same embodiment The figure which shows the cause investigation sequence of RACH transmission power abnormality incorporated in the modulation signal analysis apparatus of the embodiment The figure which shows the analysis result of the modulation accuracy displayed on the display part of the modulation signal analyzer of the embodiment The figure which shows the time characteristic of the modulation accuracy and phase error which were displayed on the display part of the modulation signal analyzer of the embodiment The figure which shows the normal code domain power displayed on the display part of the modulation signal analyzer of the embodiment The figure which shows the abnormal code domain power displayed on the display part of the modulation signal analyzer of the embodiment The figure which shows the constellation displayed on the display part of the modulation signal analyzer of the embodiment The figure which shows the constellation and cause investigation result which were displayed on the display part of the modulation signal analyzer of the embodiment The block diagram which shows schematic structure of the modulation signal analysis apparatus concerning 2nd Embodiment of this invention. The figure which shows the transition of the analysis result of the analysis item displayed on the display part of the modulation signal analyzer of the embodiment, and abnormality cause investigation Flow chart showing the overall operation of the modulation signal analyzing apparatus of the same embodiment

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Frame, 2 ... Slot, 3 ... Transmission data, 4 ... SCH, 5 ... Waveform memory, 6 ... Signal analysis part, 7 ... Operation part, 8 ... Abnormal cause investigation part, 9 ... Cause investigation sequence memory, 10 ... Signal Analysis result memory 11, 11a ... abnormality determination unit, 12 ... display control unit, 13 ... display unit, 14 ... specified value memory, 15 ... cause investigation result memory, 17 ... frequency conversion unit, 19 ... A / D converter, DESCRIPTION OF SYMBOLS 20 ... I and Q separation part, 21 ... Frame detection part, 22 ... SCH detection part, 23 ... Transmission power measurement part, 24 ... Frequency measurement part, 25 ... FFT conversion part, 26 ... Adjacent channel leakage power measurement part, 27 ... Spurious measurement unit, 28 ... back-spreading unit, 29 ... I and Q level measurement unit, 30 ... demodulation unit, 31 ... constellation calculation unit, 32 ... RACH transmission power measurement unit, 33 ... code domain power measurement unit, 34 ... Con 35 ... measurement point, 36 ... modulation method determination unit, 37 ... modulation accuracy calculation unit, 38 ... phase error calculation unit, 39 ... analysis result, 40 ... determination result, 41 ... average value, 42 ... abnormal (error) 44 ... Cause of abnormality 45 ... EVM time characteristic 46 ... Phase error time characteristic 48 ... Investigation instruction receiving part 49 ... "Help" key 51 ... Selection guide

Claims (3)

In a modulation signal analyzer for analyzing an input modulation signal,
A waveform memory (5) for storing the inputted modulation signal;
A signal analysis unit (6) for analyzing a specified analysis item or a specified measurement item for the modulation signal stored in the waveform memory and outputting an analysis result;
An abnormality determination unit (11, 11a) for determining normality / abnormality of the analysis result output from the signal analysis unit and outputting the determination result;
For each analysis item, a plurality of measurement items for the modulation signal to be investigated in order to investigate the cause of abnormality when the analysis result of the analysis item is determined to be abnormal, and the order of execution of normal / abnormal determination of the analysis result A cause investigation sequence memory (9) for storing the cause investigation sequence shown;
Upon receipt of the determination result indicating the abnormality of the analysis item output from the abnormality determination unit, each measurement item is designated to the signal analysis unit according to the cause investigation sequence of the analysis item stored in the cause investigation sequence memory. An analysis of the measurement item to determine the cause of abnormality of the analysis item (8),
Display control unit (12) for displaying on the display unit each analysis result output from the signal analysis unit, the determination result output from the abnormality determination unit, and the cause of abnormality of the analysis item investigated by the abnormality cause investigation unit And a modulated signal analyzing apparatus.   When the analysis result of the analysis item output from the signal analysis unit indicates an abnormality, the abnormality determination unit instructs the display control unit to display prompting the instruction input execution of the abnormality cause investigation execution of the analysis item. 2. The modulation according to claim 1, wherein, only when an abnormality cause investigation execution instruction for the analysis item is input, a determination result indicating that the analysis result of the analysis item for the abnormality cause investigation unit indicates an abnormality is output. Signal analysis device. Each cause investigation sequence has two or more measurement items with priorities, causes the signal analysis unit to execute each measurement item, and causes the abnormality determination unit to analyze the analysis result of each measurement item. The normal / abnormal determination is sequentially executed according to the priorities, and when the abnormality is first determined to be abnormal, the normal / abnormal determination of the analysis result of each measurement item having a priority lower than the measurement item is stopped, 2. The modulation signal analyzing apparatus according to claim 1, wherein the determined abnormality of the measurement item is caused as an abnormality cause of the analysis item.

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