JP2018019151A - Signal analyzer and signal analysis method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal analyzer and a signal analysis method which allow for high speed signal analysis with simple configuration, even when a measured device has a large number of antenna output ports.SOLUTION: A signal analyzer 10 includes a switch box 20 which switches and selects any one of multiple antenna output ports, a memory 42 for storing the output signal from an antenna output port selected by the switch box 20, and an analysis section 43 for analyzing the output signal stored by the memory 42. The switch box 20 outputs a selection time output signal that is outputted while any one of the multiple antenna output ports was selected, and a switching time output signal that is outputted when switching the multiple antenna output ports. The memory 42 stores the selection time output signal and switching time output signal, and the analysis section 43 has a configuration for analyzing the selection time output signal stored by the memory 42.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a signal analysis apparatus and a signal analysis method for analyzing a signal transmitted from, for example, a MIMO (Multiple Input Multiple Output) terminal device.

  In recent years, a three-dimensional MIMO (3D-MIMO) system in which a large number of antenna elements two-dimensionally arranged in the vertical direction and the horizontal direction are mounted on a base station and a beam is formed in the vertical direction in addition to the horizontal direction has been studied. Among 3D-MIMO systems, when the transmission antenna is larger than 8, it is called an FD-MIMO (Full Dimension-MIMO) system. Some FD-MIMO systems have more than 100 transmitting antennas.

  2. Description of the Related Art Conventionally, a measurement apparatus that can perform measurement on a device under measurement using the MIMO method can replace a device under measurement whose measurement has been completed with a new device under measurement. Is known (see, for example, Patent Document 1).

  The conventional device described in Patent Document 1 includes a connection unit having a plurality of terminals (antenna output ports) connectable to two antennas respectively provided in a plurality of devices under measurement, and two antennas of the plurality of devices under measurement. It has the structure which has the switching part which selectively connects one of these, a signal generation part, and a signal analysis part, and the control part which controls the switching operation of a switching part.

  With this configuration, the conventional one can easily switch the antenna of the device under measurement.

JP 2013-183269 A

  However, in the conventional device, when the number of antenna output ports of the device under test is about two, the antenna output port can be easily switched. However, as the number of antenna output ports of the device under test increases, the number of antenna output ports increases. There was a problem that switching would be difficult.

  Specifically, in the conventional device, for example, when the device under test has a large number of antenna output ports (for example, 64 or more) in order to support the FD-MIMO method, the transmission timing control of the device under test is performed. It becomes complicated and it becomes difficult to switch the antenna output port, and high-speed signal analysis cannot be performed.

  The present invention has been made to solve the conventional problems, and even when the device under test has a large number of antenna output ports, the signal analysis device and the signal capable of performing high-speed signal analysis with a simple configuration An object is to provide an analysis method.

  A signal analysis device according to claim 1 of the present invention is a signal analysis device (10) for analyzing an output signal of a device under test (1) having a plurality of antenna output ports (# 0 to # 101), Selection means (20) for switching and selecting any one of a plurality of antenna output ports, output signal storage means (42) for storing an output signal from the antenna output port selected by the selection means, and the output A signal analysis means (43) for analyzing the output signal stored by the signal storage means, and the selection means outputs in a state where any one of the plurality of antenna output ports is selected. And a switching output signal that is output when switching the plurality of antenna output ports, and the output signal storage means is configured to output the selection signal. When the output signal and is configured to store the switching time of output signal, said signal analyzing means has a configuration in which analyzing the selection time of output signal stored by said output signal storing means.

  With this configuration, the signal analysis device according to claim 1 of the present invention switches and selects any one of the plurality of antenna output ports, and stores the output signals output from the respective antenna output ports. Since the output signal is analyzed, even if the device under test has a large number of antenna output ports, high-speed signal analysis can be performed with a simple configuration.

  In the signal analysis device according to claim 2 of the present invention, the selection means outputs data in which the output signal at the time of selection and the output signal at the time of switching alternately appear as one captured data (60). have.

  With this configuration, the signal analysis apparatus according to claim 2 of the present invention completes the capture of the output signals at once and collects the captured data into one, so that handling of the captured data can be facilitated.

  The signal analyzing apparatus according to claim 3 of the present invention is such that the device under measurement transmits a radio frequency signal, and the radio frequency signal is transmitted between the selection unit and the output signal storage unit. Is further provided with frequency conversion means (30) for converting the frequency of the signal into a signal of a baseband frequency.

  With this configuration, the signal analysis device according to claim 3 of the present invention can perform high-speed signal analysis with a simple configuration even when a transmission device that transmits a radio frequency signal has a large number of antenna output ports. .

  A signal analysis method according to claim 4 of the present invention is a signal analysis using a signal analysis device (10) for analyzing an output signal of a device under test (1) having a plurality of antenna output ports (# 0 to # 101). A selection step (S15) of switching and selecting any one of the plurality of antenna output ports, and an output signal storage step of storing an output signal from the antenna output port selected in the selection step (S15) S18), and a signal analysis step (S21) for analyzing the output signal stored in the output signal storage step, wherein one of the plurality of antenna output ports is selected in the selection step An output signal at the time of switching, and an output signal at the time of switching output at the time of switching to switch the plurality of antenna output ports; The output signal storage step stores the selection output signal and the switching output signal, and the signal analysis step analyzes the selection output signal stored in the output signal storage step. have.

  With this configuration, the signal analysis method according to claim 1 of the present invention switches and selects any one of the plurality of antenna output ports, stores the output signals output from the respective antenna output ports, and stores them. Since the output signal is analyzed, even if the device under test has a large number of antenna output ports, high-speed signal analysis can be performed with a simple configuration.

  The present invention can provide a signal analysis device and a signal analysis method that have an effect of being able to perform high-speed measurement with a simple configuration even when the device under test has a large number of antenna output ports. .

It is a block block diagram in one Embodiment of the signal analyzer based on this invention. It is a block block diagram of the switch box in one Embodiment of the signal analyzer which concerns on this invention. It is a schematic diagram of the capture data output from the switch box in one Embodiment of the signal analyzer which concerns on this invention. It is a flowchart in one Embodiment of the signal analyzer based on this invention. It is the figure which compared and showed each process by one Embodiment of the signal analyzer based on this invention, and the conventional one.

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

  First, the configuration of an embodiment of a signal analyzing apparatus according to the present invention will be described.

  As shown in FIG. 1, the signal analyzing apparatus 10 according to the present embodiment captures (captures) and analyzes an output signal of a device under measurement (hereinafter referred to as “DUT”) 1. This DUT 1 has a large number of antenna output ports and outputs a signal in accordance with, for example, the MIMO system. For example, the DUT 1 is a transmission device that has an antenna output port connected to a multi-antenna of a base station of a mobile phone system and transmits a radio frequency signal according to the MIMO scheme. In the following description, it is assumed that DUT 1 has 102 antenna output ports.

  The signal analysis device 10 includes a switch box 20, an RF unit 30, a signal analysis unit 40, a display device 50, an operation unit 11, and a control unit 12. The signal analysis device 10 includes a microcomputer including a CPU, a ROM, a RAM, an input / output circuit to which various interfaces are connected, and the like. The signal analysis device 10 causes the microcomputer to function as each functional unit of the signal analysis device 10 by executing a control program stored in advance in the ROM.

  The switch box 20 predetermines one of a plurality of antenna output ports of the DUT 1 when the signal indicating the start of capturing the output signal of the DUT 1 (hereinafter referred to as “trigger signal”) is received from the control unit 12. The output signals from the antenna output ports are captured and the captured data is output to the RF unit 30. The switch box 20 is an example of a selection unit.

  The RF unit 30 includes an ATT (attenuator) 31, a local oscillator 32, a mixer 33, a BPF (band pass filter) 34, and an ADC (analog / digital converter) 35, and is based on a radio frequency signal (hereinafter referred to as an “RF signal”). The frequency is converted into a band frequency signal. The RF unit 30 is an example of a frequency conversion unit.

  The ATT 31 attenuates the RF signal input from the switch box 20 to a predetermined level and outputs it to the mixer 33.

  The local oscillator 32 generates a local oscillation signal having a predetermined frequency and outputs it to the mixer 33.

  The mixer 33 mixes the RF signal output from the ATT 31 and the local oscillation signal from the local oscillator 32, converts the frequency into a baseband frequency signal, and outputs the signal to the BPF 34.

  The BPF 34 filters the input signal, extracts a signal in a predetermined frequency region, and outputs the signal to the ADC 35.

  The ADC 35 converts the output signal of the BPF 34 from an analog value to a digital value and outputs it to the signal analysis unit 40.

  The signal analysis unit 40 includes an IQ conversion unit 41, a memory unit 42, and an analysis unit 43, and captures and analyzes the waveform data of the signal output from the ADC 35.

  The IQ conversion unit 41 converts the output signal of the ADC 35 into baseband data (hereinafter referred to as “I / Q data”) of an I-phase component (in-phase component) and a Q-phase component (orthogonal component), and outputs the baseband data to the memory unit 42. It is like that.

  The memory unit 42 stores the I / Q data converted by the IQ conversion unit 41 when the trigger signal is received from the control unit 12. The memory unit 42 is an example of an output signal storage unit.

  The analysis unit 43 performs a predetermined analysis on the I / Q data stored in the memory unit 42. For example, the analysis unit 43 obtains transmission power, modulation accuracy (Error Vector Magnitude, EVM), adjacent channel leakage power ratio (ACLR), phase error, phase error, amplitude error, etc. be able to. The analysis unit 43 is an example of a signal analysis unit.

  The display device 50 includes a display control unit 51 and a display unit 52. The display control unit 51 performs display control of information displayed on the display unit 52. The display unit 52 displays predetermined information based on the display control of the display control unit 51.

  The operation unit 11 is operated by the user to set analysis items, analysis conditions, determination conditions, and the like for analyzing the signal under measurement. For example, the operation unit 11 includes a display that displays a setting screen for setting various conditions, an input device such as a keyboard, a dial, or a mouse, a control circuit that controls these, software, and the like. The input of analysis conditions and the display contents of the display unit 52 are set.

  The control unit 12 is configured to set various information input by the operation unit 11 in each unit of the signal analysis device 10 and the DUT 1. The control unit 12 outputs a trigger signal to the switch box 20 and the memory unit 42 when starting to capture the output signal of the DUT 1. Further, the control unit 12 outputs a switch switching signal to the switch box 20 in order to capture the output signal of the DUT 1 at a predetermined timing for each antenna output port.

  Next, a detailed configuration of the switch box 20 will be described with reference to FIG. FIG. 2 is a diagram illustrating a configuration example of the antenna output port of the DUT 1 and the switch box 20. The switch box 20 of this configuration example includes a plurality of six-circuit / one-contact changeover switches each having six input-side terminals and one output-side terminal. Of the input side terminals of each changeover switch, the top in the figure is called the first and the bottom is called the sixth.

  As shown in FIG. 2, the DUT 1 has antenna output ports # 0 to # 101. The antenna output ports # 12 to # 89 are not shown.

  The switch box 20 includes a first changeover switch group 200, a second changeover switch group 220, and a changeover switch 21.

  The first changeover switch group 200 includes 17 changeover switches 201 to 217, and performs a changeover operation based on a switch changeover signal from the control unit 12. Note that the selector switches 203 to 215 are not shown. The changeover switch 201 can select any one of the antenna output ports # 0 to # 5 of the DUT1. The changeover switch 202 can select any one of the antenna output ports # 6 to # 11 of the DUT 1. The changeover switch 216 can select any one of the antenna output ports # 90 to # 95 of the DUT 1. The changeover switch 217 can select any one of the antenna output ports # 96 to # 101 of the DUT 1.

  The second changeover switch group 220 includes three changeover switches 221 to 223, and performs a changeover operation based on a switch changeover signal from the control unit 12. The changeover switch 221 can select any one of the antenna output ports # 0 to # 35 of the DUT 1 via the first changeover switch group 200. The changeover switch 222 can select any one of the antenna output ports # 36 to # 71 of the DUT 1 via the first changeover switch group 200. The changeover switch 223 can select any one of the antenna output ports # 72 to # 101 of the DUT 1 via the first changeover switch group 200. The changeover switch 223 uses five terminals from the first to the fifth as input terminals.

  In the changeover switch 21, the first to third input terminals are connected to the output terminals of the changeover switches 221 to 223 of the second changeover switch group 220, respectively. The changeover switch 21 is configured to select one of the output side terminals of the changeover switches 221 to 223 based on a switch changeover signal from the control unit 12.

  With the above configuration, the switch box 20 switches any one of the antenna output ports # 0 to # 101 of the DUT 1 by the switching operation of the first switch group 200, the second switch group 220, and the switch 21. Selectable.

  The control unit 12 outputs a switch switching signal to the first changeover switch group 200, the second changeover switch group 220, and the changeover switch 21 of the switch box 20, and output signals from the antenna output ports # 0 to # 101 of the DUT1. Are sequentially input to the switch box 20. For example, when the control unit 12 selects the output signal of the antenna output port # 0 of the DUT 1, the first input side terminal of the changeover switch 201, the first input side terminal of the changeover switch 221, and the changeover switch A switch switching signal is output to the switch box 20 so that the first input side terminal 21 is selected. For example, when the control unit 12 selects the output signal of the antenna output port # 101 of the DUT 1, the sixth input side terminal of the changeover switch 217, the fifth input side terminal of the changeover switch 223, A switch switching signal is output to the switch box 20 so that the third input side terminal of the switch 21 is selected.

  Next, the capture data output from the switch box 20 will be described with reference to FIG.

  As shown in FIG. 3, the capture data 60 output from the switch box 20 includes output signals of antenna output ports # 0 to # 101 indicated by “Port # 0” to “Port # 101”, and output signals. And a guard time signal indicated as “guard time”.

  Each output signal is a signal output in a state where each changeover switch in the switch box 20 is set to a predetermined position. That is, each output signal is an example of a selection output signal that is output in a state in which the switch box 20 selects any one of the plurality of antenna output ports # 0 to # 101.

  Each guard time signal is a signal output during switching of each changeover switch in the switch box 20. That is, the guard time signal is an example of a switching output signal that is output when the switch box 20 switches a plurality of antenna output ports # 0 to # 101.

  That is, the switch box 20 outputs data in which the output signal at the time of selection and the output signal at the time of switching alternately appear as one capture data 60 (capture data), and is an example of a selection unit.

  The time length of each output signal and each guard time signal can be set according to the switching time of the switch box 20 and the analysis time of the analysis unit 43, for example, both can be set to 20 milliseconds. In this case, the capture data 60 is composed of data of a short time of 4.08 seconds.

  The capture data 60 output from the switch box 20 is configured as described above, and is stored in the memory unit 42 after being processed by the RF unit 30 and the IQ conversion unit 41. The analysis unit 43 can perform a predetermined analysis by reading out the output signals (selection output signals) of the antenna output ports # 0 to # 101 from the memory unit 42 sequentially or in any order.

  If the capture data 60 stored in the memory unit 42 is output to the outside of the signal analysis device 10 as a single file and the capture data 60 is analyzed by an external device (for example, a server), faster analysis is possible. Processing is preferable.

  Next, the operation of the signal analysis apparatus 10 in the present embodiment will be described with reference to FIG.

  The control unit 12 initializes a variable n indicating the antenna output port number of the DUT 1 (step S11).

  The control unit 12 inputs measurement parameters for performing a predetermined measurement from the operation unit 11, and sets the measurement parameters in the DUT 1, the RF unit 30, the signal analysis unit 40, and the display device 50 (step S12).

  The control unit 12 outputs a predetermined control signal to the DUT 1 and starts signal output from each antenna output port of the DUT 1 (step S13). Thereafter, the DUT 1 is in a state of continuously outputting a signal to be analyzed from each antenna output port.

  The control unit 12 outputs a trigger signal to the switch box 20 and the memory unit 42 in order to start capturing the output signal of the DUT 1 (step S14).

  The control unit 12 outputs a switch switching signal for causing the switch box 20 to select the antenna output port n of the DUT 1, and causes the switch box 20 to select the antenna output port n (step S15).

  The RF unit 30 converts the radio frequency signal from the antenna output port n into a baseband frequency signal (step S16). Specifically, the ATT 31 attenuates the RF signal input from the switch box 20 to a predetermined level and outputs it to the mixer 33. The local oscillator 32 generates a local oscillation signal having a predetermined frequency and outputs it to the mixer 33. The mixer 33 mixes the RF signal output from the ATT 31 and the local oscillation signal from the local oscillator 32, converts the frequency into a baseband frequency signal, and outputs the signal to the BPF 34. The BPF 34 performs filtering of the input signal, extracts a signal in a predetermined frequency region, and outputs it to the ADC 35. The ADC 35 converts the output signal of the BPF 34 from an analog value to a digital value, and outputs it to the IQ conversion unit 41.

  The IQ conversion unit 41 converts the output signal of the antenna output port n, which is the output signal of the ADC 35, into I / Q data (step S17).

  The memory unit 42 stores the I / Q data of the antenna output port n in a predetermined memory area (step S18).

  The control unit 12 increments the variable n (Step S19).

  The control unit 12 determines whether or not the variable n has exceeded 101 of the number of antenna output ports (step S20).

  If it is determined in step S20 that the variable n exceeds 101, the analysis unit 43 can perform a predetermined signal analysis (step S21), and the display device 50 displays the signal analysis result (step S22). ).

  On the other hand, if it is not determined in step S20 that the variable n has exceeded 101, the process returns to step S15.

  Next, each processing by the signal analyzing apparatus 10 in the present embodiment and the conventional one will be compared and explained based on FIG.

  First, as shown in FIG. 5A, the conventional one performs DUT control, signal capture, and signal analysis for each antenna output port. Therefore, in the prior art, a great deal of processing time is required as the number of antenna output ports increases. Further, in the conventional device, since the capture data exists for each antenna output port, the capture data increases as the antenna output port increases, and it is not easy to handle the capture data.

  For example, when using the antenna output port # 1, the DUT control uses the antenna output port # 1 and does not use the other antenna output ports. This control includes confirmation of the above, notification of starting signal capture, and the like.

On the other hand, in the present embodiment, as shown in FIG. 5B, the antenna output ports # 0 to #n are combined to perform DUT control, signal capture, and signal analysis. Therefore, in this embodiment, the following effects can be obtained.
(1) Since the capture of the output signals of the DUT is completed at once, control of the DUT is facilitated, and signal analysis can be performed at a higher speed than before even when the antenna output ports are increased.
(2) Since it is only necessary to continuously output a signal to be analyzed from the DUT when capturing data is acquired, unlike the conventional one, it is not necessary to perform on / off control of the signal for each antenna output port of the DUT.
(3) Since the capture data is combined into one, it becomes easy to handle the capture data. In particular, when capturing data is transmitted to the outside of the signal analyzing apparatus 10, there is only one file including the capturing data, which facilitates file transmission / reception and analysis.

  As described above, the signal analysis device 10 according to the present embodiment switches the connection between the plurality of antenna output ports # 0 to # 101 of the DUT 1 and the memory unit 42, and outputs signals from the respective antenna output ports. Is stored, and the stored output signal is analyzed, so that even when the DUT 1 has a large number of antenna output ports, high-speed signal analysis can be performed with a simple configuration.

  As described above, the signal analysis device and the signal analysis method according to the present invention have the effect that high-speed measurement can be performed with a simple configuration even when the device under test has a large number of antenna output ports. The present invention is useful as a signal analysis device and a signal analysis method for analyzing a signal transmitted from a MIMO terminal device.

1 DUT (device under test)
10 Signal analyzer 20 Switch box (selection means)
30 RF section (frequency conversion means)
40 Signal Analysis Unit 41 IQ Conversion Unit 42 Memory Unit (Output Signal Storage Unit)
43 Analysis unit (signal analysis means)
60 Capture data (capture data)
# 0 to # 101 Antenna output port

Claims (4)

A signal analyzer (10) for analyzing an output signal of a device under test (1) having a plurality of antenna output ports (# 0 to # 101),
Selection means (20) for switching and selecting any one of the plurality of antenna output ports;
Output signal storage means (42) for storing an output signal from the antenna output port selected by the selection means;
Signal analysis means (43) for analyzing the output signal stored by the output signal storage means;
With
The selection means outputs a selection output signal that is output in a state in which any one of the plurality of antenna output ports is selected, and a switching output signal that is output when switching the plurality of antenna output ports. Is what
The output signal storage means stores the selection output signal and the switching output signal,
The signal analysis device is characterized in that the signal analysis means analyzes the output signal at the time of selection stored by the output signal storage means.   2. The signal analysis apparatus according to claim 1, wherein the selection unit outputs data in which the output signal at the time of selection and the output signal at the time of switching alternately appear as one captured data (60). . The device under test is a transmission device that transmits a radio frequency signal,
The frequency conversion means (30) for frequency-converting the radio frequency signal into a baseband frequency signal between the selection means and the output signal storage means is further provided. Signal analysis equipment. A signal analysis method using a signal analysis device (10) for analyzing an output signal of a device under test (1) having a plurality of antenna output ports (# 0 to # 101),
A selection step (S15) of switching and selecting any one of the plurality of antenna output ports;
An output signal storing step (S18) for storing an output signal from the antenna output port selected in the selecting step;
A signal analysis step (S21) for analyzing the output signal stored in the output signal storage step;
Including
In the selection step, a selection output signal output in a state where any one of the plurality of antenna output ports is selected, and a switching output signal output in switching when switching the plurality of antenna output ports are output. And
In the output signal storing step, the output signal at the time of selection and the output signal at the time of switching are stored,
In the signal analysis step, the output signal at the time of selection stored in the output signal storage step is analyzed.
A signal analysis method characterized by the above.

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