JP6959315B2 - Signal analyzer and signal analysis method - Google Patents

Description

The present invention relates to a signal analysis device and a signal analysis method, and more particularly to a signal analysis device and a signal analysis method for analyzing signal characteristics of a periodic signal based on a time division duplex system.

Conventionally, as duplex systems in wireless communication systems, there are a frequency division duplex (FDD) system that divides an uplink and a downlink by a frequency, and a time division duplex (Time Division Duplex) that divides an uplink and a downlink by time. The TDD) method is known. In the FDD method, the uplink signal and the downlink signal are transmitted and received at different frequencies at the same time. On the other hand, in the TDD system, the uplink signal and the downlink signal are transmitted and received at different times of the same frequency.

In a wireless communication system using the TDD system, a wireless terminal alternately transmits and receives radio signals at the same frequency. For this reason, the wireless signal transmitted from the wireless terminal alternately has a transmission on period (hereinafter, also referred to as an “on section”) and a transmission off period (hereinafter, also referred to as an “off section”). .. As an example, FIG. 7 shows an example of the power of a TDD signal in which 0 ms to 9 ms in one frame (10 ms) is an off section and 9 ms to 10 ms is an on section.

When analyzing a radio signal having such an on section and an off section, the analysis result changes depending on how the analysis section is provided. Therefore, as shown in FIG. 8, when performing spectrum analysis or modulation analysis of a device under test (DUT) 110 corresponding to the TDD method with a signal analysis device 120 such as a spectrum analyzer or a signal analyzer, for example, DUT. It is necessary to use the trigger signal output from the above and limit the analysis section to the on section of the radio signal for measurement (see, for example, Patent Document 1).

Japanese Patent No. 6275084

However, many wireless terminals for 5G NR (New Radio) systems in recent years do not output a trigger signal, and in a performance test using such a wireless terminal as a DUT, a test is performed between the test antenna and the DUT. So-called OTA (Over The Air) tests, in which signals are transmitted and received by wireless communication, are being conducted.

If the trigger signal is not output from the DUT, the signal to be measured to the signal analyzer will be displayed each time the DUT is changed or the DUT standard (for example, 5G NR, TD-LTE, GSM®, etc.) is switched. Since the input timing changes, it becomes necessary to manually readjust the analysis interval. Such adjustment is complicated, and there is a problem such as inducing a setting error of the analysis section.

The present invention has been made to solve such a conventional problem, does not require an external trigger signal input, and analyzes only the on-section of a periodic signal as a signal to be measured. It is an object of the present invention to provide a signal analysis device and a signal analysis method that can be automatically set as a section.

In order to solve the above problems, the signal analysis device according to the present invention is a signal analysis device that analyzes the signal characteristics of a periodic signal based on a time division duplex method including a plurality of frames having a known frame length. A periodic trigger generating unit that generates a plurality of triggers at time intervals of the frame length, a head position detecting unit that detects the head position of the first frame among the plurality of frames, and a head position of the first frame. A timing offset detection unit that detects the time difference from the timing of the first trigger among the plurality of triggers as a timing offset, and a burst length detection unit that detects the time of the on section of the first frame as the burst length. A burst offset detection unit that detects the time difference between the on section of the first frame and the start position of the first frame as a burst offset, and an analysis section for the second frame of the plurality of frames are set. The analysis section setting unit includes an analysis section setting unit and an analysis processing unit that analyzes the signal characteristics of the second frame over the analysis section, and the analysis section setting unit sets the sum of the timing offset and the burst offset into the frame. By calculating the remainder with the length, the start position of the on section of the second frame based on the timing of the second trigger of the plurality of triggers is calculated as the start position of the analysis section. The end position calculation that calculates the sum of the unit, the start position of the analysis section calculated by the start position calculation unit, and the burst length as the end position of the analysis section based on the timing of the second trigger. It is a structure including a part and.

With this configuration, the signal analysis apparatus according to the present invention internally generates a trigger at a time interval of the frame length of the periodic signal, which is the signal to be measured, so that an external trigger signal input is not required and the periodic signal is used. Therefore, only the on section can be automatically set as the analysis section. As a result, even in a measurement environment in which a trigger signal from the outside cannot be input, it is possible to measure only the on section of the periodic signal. In addition, since the setting of the analysis section is automated, the time and effort for setting can be significantly reduced. For example, the signal analysis device according to the present invention can easily perform a test such as switching the communication method with time on a DUT (smartphone or the like) that does not output a trigger signal.

Further, the signal analysis apparatus according to the present invention includes a local signal source that outputs a local signal, a sweep unit that frequency sweeps the local signal output from the local signal source, and the local frequency sweep by the sweep unit. A / D that mixes a signal and the periodic signal to perform frequency conversion, and samples the periodic signal frequency-converted by the mixer and converts it into digital data, and outputs the digital data to the analysis processing unit. A converter may be further provided, and the sweep unit may be configured to frequency sweep the local signal over the analysis section set by the analysis section setting unit.

With this configuration, the signal analysis device according to the present invention does not require an external trigger signal input, and can perform spectrum analysis by frequency sweeping only the on-section of the periodic signal as the signal to be measured.

Further, the signal analysis method according to the present invention is a signal analysis method for analyzing the signal characteristics of a periodic signal based on a time-division duplex method including a plurality of frames having a known frame length, and a plurality of triggers are set to the frame. A periodic trigger generation step that is generated at long time intervals, a start position detection step that detects the start position of the first frame among the plurality of frames, a start position of the first frame, and the plurality of triggers. A timing offset detection step that detects the time difference from the timing of the first trigger as a timing offset, a burst length detection step that detects the time of the on section of the first frame as a burst length, and the first A burst offset detection step that detects the time difference between the frame on section and the start position of the first frame as a burst offset, and an analysis section setting step that sets an analysis section for the second frame of the plurality of frames. The analysis processing step for analyzing the signal characteristics of the second frame over the analysis section is provided, and the analysis section setting step calculates the sum of the timing offset and the burst offset by the frame length. A start position calculation step for calculating the start position of the on section of the second frame based on the timing of the second trigger among the plurality of triggers as the start position of the analysis section, and the start position. A configuration including an end position calculation step of calculating the sum of the start position of the analysis section and the burst length calculated by the calculation step as the end position of the analysis section based on the timing of the second trigger. Is.

With this configuration, the signal analysis method according to the present invention generates a trigger at a time interval of the frame length of the periodic signal, which is the signal to be measured, independently of the periodic signal, so that the trigger signal input from the DUT is not required. Only the on section of the periodic signal can be automatically set as the analysis section. As a result, even in a measurement environment in which a trigger signal from the outside cannot be input, it is possible to measure only the on section of the periodic signal. In addition, since the setting of the analysis section is automated, the time and effort for setting can be significantly reduced. For example, the signal analysis method according to the present invention can easily perform a test such as switching the communication method with time on a DUT (smartphone or the like) that does not output a trigger signal.

The present invention provides a signal analysis device and a signal analysis method that do not require an external trigger signal input and can automatically set only the on section of a periodic signal as a signal to be measured as an analysis section. It is to provide.

It is a block diagram which shows the structure of the signal analysis apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structure of the modulation analysis part provided in the signal analysis apparatus which concerns on embodiment of this invention. It is a figure which shows the trigger, the power of a periodic signal, and the timing of a frame of a periodic signal, (a) shows the case where both Timing Offset and Gate Offset are positive values, and (b) is the case where Timing Offset is a negative value and Gate The case where Offset is a positive value is shown, and the case where both Timing Offset and Gate Offset are negative values are shown in (c). It is a flowchart for demonstrating the processing of the signal analysis method by the signal analysis apparatus which concerns on embodiment of this invention. It is a flowchart for demonstrating the process of the analysis section setting step in the flowchart of FIG. 4 in detail. It is a flowchart for demonstrating the process of the analysis processing step in the flowchart of FIG. 4 in detail. It is a graph which shows an example of the on section and the off section of a TDD signal. It is a block diagram which shows the example of the conventional measurement system which uses an external trigger signal.

Hereinafter, embodiments of the signal analysis apparatus and the signal analysis method according to the present invention will be described with reference to the drawings.

The signal analysis device 100 according to the present embodiment analyzes the signal characteristics of the periodic signal S based on the TDD method including a plurality of frames having a known frame length. As shown in FIG. 1, the signal analysis device 100 includes an analog signal processing unit 10, an A / D converter (ADC) 20, a digital signal processing unit 30, a periodic trigger generation unit 40, and an analysis section setting unit 50. A display unit 60, an operation unit 61, and a control unit 62 are provided.

The DUT1 is, for example, a wireless terminal or a base station that has a wireless communication antenna and an RF circuit and can output a periodic signal based on the TDD system. Examples of the communication standard of DUT1 include 5G NR, TD-LTE, LTE-Advanced, GSM (registered trademark), TD-SCDMA, Bluetooth (registered trademark) and the like. The DUT 1 and the analog signal processing unit 10 may be connected by wire with a coaxial cable or the like, or may be wirelessly connected via a wireless communication antenna.

The analog signal processing unit 10 performs analog signal processing such as frequency conversion on the periodic signal S output from the DUT 1, and includes an attenuator (ATT) 11, a local signal source 12, a mixer 13, and an RBW filter. It has 14, a logarithmic (LOG) converter 15, a detector 16, a VBW filter 17, a switch (SW) 18, and a sweep unit 19.

The ATT 11 is an electronic component that has an internal resistance and attenuates the high-frequency periodic signal S from the DUT1 to a signal level that can be processed by the digital signal processing unit 30 in the subsequent stage, and does not change the impedance.

The local signal source 12 outputs a sine wave having a frequency higher or lower than the value of the frequency of the original periodic signal S by the value of the frequency of the conversion destination as the local signal. The local signal output from the local signal source 12 is swept over a predetermined frequency range by the sweep lamp signal output from the sweep unit 19.

_{The mixer 13 mixes the periodic signal S} of the frequency f S attenuated by the ATT 11 _{and the local signal of the frequency f L} output from the local signal source 12, and outputs the output signal having the sum and difference frequencies of the two signals. That is, it generates an intermediate frequency signal of intermediate frequency | f _L − f _S | or f _L + f _S. That is, the mixer 13 is adapted to perform frequency conversion by mixing the periodic signal S with the local signal.

The RBW filter 14 is composed of an analog bandpass filter or the like, and filters the intermediate frequency signal output from the mixer 13 with a resolution bandwidth corresponding to the communication standard of the periodic signal S.

The LOG converter 15 converts the output signal level of the RBW filter 14 into decibel units and outputs it to the detector 16.

The detector 16 is, for example, an envelope detector, and is adapted to convert the output of the LOG converter 15 into direct current.

The VBW filter 17 is composed of, for example, an analog low-pass filter and has a video bandwidth determined by a cutoff frequency. The VBW filter 17 performs band limitation processing of a predetermined video bandwidth on the signal output from the detector 16, and performs high frequency components (noise) of the frequency spectrum waveform finally displayed on the display unit 60. The signal with the component) removed is output.

The SW 18 is configured to take either a state in which the output side of the mixer 13 is directly connected to the ADC 20 or a state in which the output side of the VBW filter 17 is connected to the ADC 20. The signal analysis device 100 of the present embodiment is configured to switch between a modulation analysis mode by the modulation analysis unit 34 described later and a spectrum analysis mode by the spectrum analysis unit 35 described later by the SW18 and the SW31 described later.

Specifically, in the modulation analysis mode, the SW 18 directly inputs the intermediate frequency signal from the mixer 13 to the ADC 20. Further, the digital data output from the ADC 20 by the SW 31 is input to the orthogonal demodulation unit 32 described later. On the other hand, in the spectrum analysis mode, the output signal of the VBW filter 17 is input to the ADC 20 by the SW18. Further, the digital data output from the ADC 20 by the SW 31 is input to the spectrum analysis unit 35, which will be described later.

The sweep unit 19 is a spectrum analysis mode in which the output side of the VBW filter 17 is connected to the ADC 20 by the SW18, and is _{a sweep lamp for sweeping the frequency f L of the} local signal output from the local signal source 12 over a predetermined frequency range. It generates a signal. In the present embodiment, the sweep unit 19 is set by the analysis section setting unit 50 by outputting the sweep lamp signal corresponding to the analysis section set by the analysis section setting unit 50, which will be described later, to the local signal source 12. Frequency sweep the local signal over the analysis interval. In the modulation analysis mode in which the output side of the mixer 13 is directly connected to the ADC 20 by the SW 18, the frequency f _{L of the} local signal output from the local signal source 12 is fixed.

The ADC 20 samples the intermediate frequency signal output from the mixer 13 at a predetermined sampling rate and converts it into digital data in the modulation analysis mode in which the output side of the mixer 13 and the ADC 20 are connected by the SW18. The ADC 20 outputs this digital data to the digital signal processing unit 30.

Further, the ADC 20 samples the output of the VBW filter 17 at a predetermined sampling rate and converts it into digital data in the spectrum analysis mode in which the output side of the VBW filter 17 and the ADC 20 are connected by the SW18. The ADC 20 outputs this digital data to the digital signal processing unit 30.

The digital signal processing unit 30 performs digital signal processing on the digital data of the periodic signal S output from the ADC 20, and includes a SW31, an orthogonal demodulation unit 32, a modulation analysis unit 34, and a spectrum analysis unit 35. The analysis processing unit 33 and the like are included.

The SW 31 is configured to selectively input the digital data output from the ADC 20 to either the orthogonal demodulation unit 32 or the spectrum analysis unit 35.

The orthogonal demodulation unit 32 orthogonally demodulates the digital data of the periodic signal S output from the SW31 in the modulation analysis mode to generate orthogonal signals I (t) and Q (t) that are orthogonal to each other. .. As the orthogonal demodulation unit 32, for example, an orthogonal distributor using a Hilbert transform can be used.

As shown in FIG. 2, the modulation analysis unit 34 includes a head position detection unit 34a, a timing offset detection unit 34b, a burst length detection unit 34c, a burst offset detection unit 34d, and a modulation analysis processing unit 34e. .. The modulation analysis processing unit 34e performs predetermined signal analysis processing on the orthogonal signals I (t) and Q (t) output from the orthogonal demodulation unit 32 in the modulation analysis mode. The signal analysis processing executed by the modulation analysis unit 34 includes, for example, generation of time-series data or spectrum showing time changes such as amplitude (power), phase, and frequency of the periodic signal S, channel power (CHP), and occupied bandwidth. (OBW), adjacent channel leakage power ratio (ACLR), burst average power, modulation accuracy (EVM), transmission power level, transmission spectrum mask, error vector amplitude, and other measurements to evaluate the quality of the periodic signal S. ..

The spectrum analysis unit 35 performs a predetermined signal analysis process on the digital data of the periodic signal S output from the SW 31 in the spectrum analysis mode. The signal analysis processing executed by the spectrum analysis unit 35 includes, for example, the generation of the spectrum of the periodic signal S, the channel power (CHP), the occupied bandwidth (Occupied Band Width: OBW), and the adjacent channel leakage power ratio (Adjacent). Measurements for evaluating the quality of the periodic signal S such as Channel Leakage Ratio (ACLR), Spectrum Emission Mask (SEM), spurious emission, and burst average power can be mentioned.

As shown in FIG. 3A and the like, the periodic trigger generation unit 40 generates a plurality of triggers 70 including the first trigger 71 and the second trigger 72 at time intervals of the frame length of the periodic signal S. It is designed to be output to the analysis processing unit 33. The timings of the trigger 70, the power Pw of the periodic signal S, and the frame 80 of the periodic signal S are as shown in FIG. 3A and the like, for example. The periodic signal S is composed of a plurality of frames 80 including a first frame 81 and a second frame 82 having known frame lengths. Further, since the same pattern is repeated without interruption of the periodic signal S, the time interval between the trigger 70 and the start position of the frame 80 of the periodic signal S is analyzed regardless of the analysis mode (modulation analysis mode or spectrum analysis mode). It is constant in unit 33.

The head position detection unit 34a of the modulation analysis unit 34 shown in FIG. 2 is included in the periodic signal S by, for example, sliding correlation processing, using a reference frame prepared in advance having the same format as the frame 80 of the periodic signal S. The head position of the first frame 81 among the plurality of frames 80 is detected.

The timing offset detection unit 34b detects the time difference between the head position of the first frame 81 and the timing of the first trigger 71 as a timing offset (hereinafter, also referred to as “Timing Offset”).

The burst length detection unit 34c detects the time of the on section of the first frame 81 as the burst length (hereinafter, also referred to as “Burst Length”). The burst offset detection unit 34d detects the time difference between the on section of the first frame 81 and the head position of the first frame 81 as a burst offset (hereinafter, also referred to as “Burst Offset”). For example, as shown in FIG. 7, in a TDD signal in which 0 ms to 9 ms in one frame (10 ms) is an off section and 9 ms to 10 ms is an on section, Burst Offset = 9 ms and Burst Length = 1 ms.

The burst length detection unit 34c and the burst offset detection unit 34d are used to provide information regarding the on-section of the periodic signal S set by the operation input to the operation unit 61 by the user (for example, in the case of 5G NR, SS, PDSCH, PUSCH, PDCCH, etc.). It is possible to calculate the Burst Length and Burst Offset based on the settings related to the slot of the channel. Alternatively, the burst length detection unit 34c and the burst offset detection unit 34d acquire data on the time change of the power of the periodic signal S by the modulation analysis processing unit 34e, and calculate the Burst Length and Burst Offset based on the acquired data. It is also possible to do. When a plurality of on sections exist in the frame 80 of the periodic signal S, the burst length detection unit 34c and the burst offset detection unit 34d select one arbitrary on section (for example, the longest on section) and burst length. And Burst Offset are calculated.

The analysis section setting unit 50 shown in FIG. 1 includes a start position calculation unit 51 and an end position calculation unit 52, and sets an analysis section for the second frame 82 of the plurality of frames 80. There is. Hereinafter, the length of the analysis section is also referred to as "Gate Length". The analysis processing unit 33 analyzes the signal characteristics of the second frame 82 over the analysis section set by the analysis section setting unit 50.

The start position calculation unit 51 calculates the sum of the Timing Offset and the Burst Offset with the frame length of the periodic signal S (hereinafter, also referred to as “Frame Length”) as a remainder, and uses the timing of the second trigger 72 as a reference. The start position of the on section of the second frame 82 (hereinafter, also referred to as “Gate Delay”) is calculated as the start position of the analysis section. The Gate Delay and Gate Length are calculated by the following equations (1) to (3). In equation (3),% represents the modulo operation. That is, the Gate Delay is a positive value smaller than the frame length of the periodic signal S.

Gate Offset ＝ Timing Offset ＋ Burst Offset ・ ・ ・ (1)
Gate Delay = Gate Offset% Frame Length ・ ・ ・ (2)
Gate Length = Burst Length ・ ・ ・ (3)

FIG. 3A shows an example in which the head position of the first frame 81 detected by the head position detection unit 34a appears after the first trigger 71. In this case, since the Timing Offset is a positive value, the Gate Offset is also a positive value. In the example of FIG. 3A, since the Gate Offset is longer than the frame length, the start position of the on section of the second frame 82 with respect to the timing of the second trigger 72, that is, the Gate Delay is from the equation (2). It is given by Gate Offset-Frame Length.

FIG. 3B shows an example in which the head position of the first frame 81 detected by the head position detection unit 34a appears before the first trigger 71. In the example of FIG. 3B, the Timing Offset is a negative value and the Burst Offset is larger than the absolute value of the Timing Offset, so that the Gate Delay is equal to the Gate Offset from the equation (2).

FIG. 3C shows an example in which the head position of the first frame 81 detected by the head position detection unit 34a appears before the first trigger 71. In the example of FIG. 3C, the Gate Offset has a negative value because the Timing Offset is a negative value and the Burst Offset is smaller than the absolute value of the Timing Offset. Therefore, the Gate Delay is given by the Gate Offset + Frame Length from the equation (2).

The end position calculation unit 52 sets the sum of the Gate Delay for the second frame 82 calculated by the start position calculation unit 51 and the Burst Length (that is, Gate Length) of the first frame 81 for the second trigger 72. It is calculated as the end position of the analysis section based on the timing.

In this way, after the Timing Offset, Burst Offset, and Burst Length are obtained by the modulation analysis unit 34, the analysis section setting unit 50 analyzes the start position and end position of the analysis section determined by the Gate Delay and Gate Length. The processing unit 33 and the control unit 62 are notified. As a result, in the spectrum analysis mode, the local signal output from the local signal source 12 is frequency-swept only in the analysis section set by the analysis section setting unit 50, and the signal analysis process for the periodic signal S in the spectrum analysis unit 35 is performed. It is performed only for the analysis section. Further, in the modulation analysis mode, the signal analysis processing for the periodic signal S in the modulation analysis processing unit 34e is performed only for the analysis section set by the analysis section setting unit 50.

The display unit 60 is composed of a display device such as an LCD or a CRT, and displays an analysis processing result or the like by the analysis processing unit 33. Further, the display unit 60 displays operation targets such as buttons, soft keys, pull-down menus, and text boxes for setting measurement conditions and the like according to the control signal output from the control unit 62. There is.

The operation unit 61 is for receiving an operation input by the user, and is composed of, for example, a touch panel provided on the display unit 60. Alternatively, the operating unit 61 may be configured to include an input device such as a keyboard or mouse. Further, the operation unit 61 may be configured by an external control device that performs remote control by a remote command or the like. The operation input to the operation unit 61 is detected by the control unit 62. For example, the operation unit 61 can specify information about the frame length of the periodic signal S and the on section of the periodic signal S, or the user can specify switching between the modulation analysis mode and the spectrum analysis mode. ..

The control unit 62 is composed of, for example, a microcomputer including a CPU, ROM, RAM, HDD, etc., a personal computer, or the like, and controls the operation of each of the above units constituting the signal analysis device 100. Further, the control unit 62 can configure at least a part of the digital signal processing unit 30 and the analysis section setting unit 50 by software by transferring a predetermined program stored in the ROM or the like to the RAM and executing the program. Is. At least a part of the digital signal processing unit 30 and the analysis section setting unit 50 can be configured by a digital circuit such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). Alternatively, at least a part of the digital signal processing unit 30 and the analysis section setting unit 50 can be configured by appropriately combining hardware processing by a digital circuit and software processing by a predetermined program.

Hereinafter, the flowchart of FIG. 4 is shown with respect to a signal analysis method for analyzing the signal characteristics of the periodic signal S based on the TDD method including a plurality of frames 80 having a known frame length using the signal analysis device 100 according to the present embodiment. An example of the process will be described with reference to it.

First, the periodic trigger generation unit 40 generates a plurality of triggers 70 at time intervals of the frame length of the periodic signal S (periodic trigger generation step S1).

Next, the control unit 62 sets the analysis mode to the modulation analysis mode in response to the operation input to the operation unit 61 by the user (step S2).

Next, the head position detection unit 34a detects the head position of the first frame 81 among the plurality of frames 80 of the periodic signal S (head position detection step S3).

Next, the timing offset detection unit 34b detects the time difference between the start position of the first frame 81 and the timing of the first trigger 71 among the plurality of triggers 70 as a timing offset (timing offset detection step S4). ..

Next, the burst length detection unit 34c detects the time of the on section of the first frame 81 as the Burst Length (burst length detection step S5).

Next, the burst offset detection unit 34d detects the time difference between the on section of the first frame 81 and the start position of the first frame 81 as the Burst Offset (burst offset detection step S6).

Next, the analysis mode is specified by the operation input to the operation unit 61 by the user (step S7).

Next, the analysis section setting unit 50 sets an analysis section for the second frame 82 of the plurality of frames 80 (analysis section setting step S8). The details of this process will be described with reference to the flowchart of FIG. 5 described later.

Next, the analysis processing unit 33 analyzes the signal characteristics of the second frame 82 over the analysis section set in step S8 (analysis processing step S9). The details of this process will be described with reference to the flowchart of FIG. 6 described later.

Hereinafter, the process of the analysis section setting step S8 will be described with reference to the flowchart of FIG.

First, the start position calculation unit 51 modulo-calculates the sum of the Timing Offset detected in step S4 and the Burst Offset detected in step S6 by the frame length. As a result, the start position calculation unit 51 calculates the Gate Delay of the on section of the second frame 82 based on the timing of the second trigger 72 of the plurality of triggers 70 as the start position of the analysis section ( Start position calculation step S11).

Next, the end position calculation unit 52 analyzes the sum of the Gate Delay calculated in step S11 and the Burst Length (that is, Gate Length) detected in step S5 with reference to the timing of the second trigger 72. It is calculated as the end position of the section (end position calculation step S12).

Next, the analysis section setting unit 50 notifies the analysis processing unit 33 and the control unit 62 of the start position and the end position of the analysis section calculated in steps S11 and S12 (step S13). As a result, the analysis section for the second frame 82 is automatically set.

Hereinafter, the process of the analysis process step S9 will be described with reference to the flowchart of FIG.

The control unit 62 determines whether the analysis mode specified in step S7 is the modulation analysis mode or the spectrum analysis mode (step S21).

When it is determined in step 21 that the analysis mode is the modulation analysis mode, the modulation analysis unit 34 uses the second frame 82 over the analysis section based on the start position and end position of the analysis section notified in step S13. Is captured (step S22).
Next, the modulation analysis unit 34 analyzes the signal characteristics of the on section of the second frame 82 using the data of the second frame 82 captured in step S22 (step S23).

On the other hand, when it is determined in step 21 that the analysis mode is the spectrum analysis mode, the sweep unit 19 is output from the local signal source 12 based on the start position and end position of the analysis section notified in step S13. The local signal is frequency swept over the analysis section (step S24).

Next, the spectrum analysis unit 35 analyzes the signal characteristics of the on-section of the second frame 82 by using the data of the second frame 82 obtained by the frequency sweep in step S24 (step S25).

Next, the display unit 60 displays the analysis result in step S23 or step S25 (step S26).

As described above, the signal analysis device 100 according to the present embodiment internally generates a trigger 70 at a time interval of the frame length of the periodic signal S, which is the signal to be measured, so that an external trigger signal input is required. Instead, only the on section of the periodic signal S can be automatically set as the analysis section. As a result, even in a measurement environment in which a trigger signal from the outside cannot be input, it is possible to measure only the on section of the periodic signal S. In addition, since the setting of the analysis section is automated, the time and effort for setting can be significantly reduced. For example, the signal analysis device 100 according to the present embodiment can easily perform a test such that the communication method is switched with time for DUT1 (smartphone or the like) that does not output a trigger signal.

Further, when the signal analysis device 100 according to the present embodiment includes a plurality of analysis units (for example, a plurality of measurement software) such as a modulation analysis unit 34 and a spectrum analysis unit 35, the signal analysis device 100 uses a common trigger 70, respectively. Only the on section of the periodic signal S can be automatically set as the analysis section for the analysis unit of.

Further, the signal analysis device 100 according to the present embodiment does not require an external trigger signal input, and can perform spectrum analysis by frequency sweeping only the on section of the periodic signal S as the signal to be measured. That is, the signal analysis device 100 sets the gate sweep section at the time of spectrum analysis by linking the information of the on section of the periodic signal S obtained by the modulation analysis unit 34 with the spectrum analysis function of the spectrum analysis unit 35. Can be automated.

1 DUT
10 Analog signal processing unit 12 Local signal source 13 Mixer 19 Sweeping unit 20 ADC
30 Digital signal processing unit 33 Analysis processing unit 34 Modulation analysis unit 34a Head position detection unit 34b Timing offset detection unit 34c Burst length detection unit 34d Burst offset detection unit 34e Modulation analysis processing unit 35 Spectrum analysis unit 40 Periodic trigger generation unit 50 Analysis section Setting unit 51 Start position calculation unit 52 End position calculation unit 60 Display unit 61 Operation unit 62 Control unit 70 Trigger 71 First trigger 72 Second trigger 80 Frame 81 First frame 82 Second frame 100 Signal analysis device

Claims (3)

A signal analysis device (100) for analyzing the signal characteristics of a periodic signal (S) based on a time division duplex system including a plurality of frames (80) having known frame lengths.
A periodic trigger generator (40) that generates a plurality of triggers (70) at time intervals of the frame length,
A head position detecting unit (34a) for detecting the head position of the first frame (81) among the plurality of frames, and
A timing offset detection unit (34b) that detects the time difference between the start position of the first frame and the timing of the first trigger (71) among the plurality of triggers as a timing offset.
A burst length detection unit (34c) that detects the time of the on section of the first frame as the burst length, and
A burst offset detection unit (34d) that detects the time difference between the on section of the first frame and the start position of the first frame as a burst offset, and
An analysis section setting unit (50) for setting an analysis section for the second frame (82) of the plurality of frames, and an analysis section setting unit (50).
An analysis processing unit (33) that analyzes the signal characteristics of the second frame over the analysis section is provided.
The analysis section setting unit
By performing the remainder calculation of the sum of the timing offset and the burst offset with the frame length, the on-section of the second frame with reference to the timing of the second trigger (72) of the plurality of triggers can be calculated. A start position calculation unit (51) that calculates the start position as the start position of the analysis section,
The end position calculation unit (52) that calculates the sum of the start position of the analysis section and the burst length calculated by the start position calculation unit as the end position of the analysis section based on the timing of the second trigger. ), And a signal analysis device. A local signal source (12) that outputs a local signal and
A sweeping unit (19) for frequency sweeping the local signal output from the local signal source, and
A mixer (13) that mixes and frequency-converts the local signal and the periodic signal that have been frequency-swept by the sweep unit, and
An A / D converter (20) that samples the periodic signal frequency-converted by the mixer, converts it into digital data, and outputs the digital data to the analysis processing unit.
The signal analysis device according to claim 1, wherein the sweep unit sweeps the frequency of the local signal over the analysis section set by the analysis section setting unit. A signal analysis method for analyzing the signal characteristics of a periodic signal (S) based on a time division duplex system including a plurality of frames (80) having known frame lengths.
A periodic trigger generation step (S1) in which a plurality of triggers (70) are generated at time intervals of the frame length, and
A start position detection step (S3) for detecting the start position of the first frame (81) among the plurality of frames, and
A timing offset detection step (S4) for detecting the time difference between the start position of the first frame and the timing of the first trigger (71) among the plurality of triggers as a timing offset.
The burst length detection step (S5) for detecting the time of the on section of the first frame as the burst length, and
A burst offset detection step (S6) for detecting the time difference between the on section of the first frame and the start position of the first frame as a burst offset, and
An analysis section setting step (S8) for setting an analysis section for the second frame (82) of the plurality of frames, and an analysis section setting step (S8).
An analysis processing step (S9) for analyzing the signal characteristics of the second frame over the analysis section is provided.
The analysis section setting step is
By performing the remainder calculation of the sum of the timing offset and the burst offset with the frame length, the on-section of the second frame with reference to the timing of the second trigger (72) of the plurality of triggers can be calculated. A start position calculation step (S11) for calculating the start position as the start position of the analysis section, and
The end position calculation step (S12) in which the sum of the start position of the analysis section calculated by the start position calculation step and the burst length is calculated as the end position of the analysis section based on the timing of the second trigger. ), And a signal analysis method comprising.

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