JP2012039567A - Jitter adding apparatus and jitter adding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it easy to set parameters for a jitter to be added to the subject signal to which the jitter is to be added.SOLUTION: A jitter adding apparatus 1, which adds an arbitrarily set jitter to the subject signal to which the jitter is to be added, comprises a display unit 15 which displays parameter graph information consisting of 2-dimensional graph data whose coordinate axis is composed of two parameters, a phase modulation quantity and a modulation frequency, and indicating a jitter settable range which is set for each piece of equipment; an operation unit 11 which is manipulated when selecting any position within the jitter settable range of parameter graph information by a pointer P displayed on the same screen that displays the parameter graph information; and a control unit 13 which sets each parameter for a jitter to be added to the subject signal according to the coordinate position of the pointer.

Description

  The present invention relates to a jitter adding apparatus and a jitter adding method for adding jitter having desired parameter settings to a signal to be added.

  In a digital transmission system, if a data signal phase jitter (phase fluctuation) or a signal time shift increases, the data signal cannot be transmitted normally. For this reason, the electronic devices used in this type of system and the components used in these systems must satisfy the jitter tolerance (strength) standard defined by ITU-T (International Telecommunication Union-Telecommunication Standardization Sector). . This jitter tolerance standard represents how much a device suppresses and outputs jitter of an input signal when a signal having a predetermined amount of jitter is input to the device under measurement.

  Here, a jitter signal, which is a jitter-modulated signal for measuring the jitter tolerance, will be described with reference to FIG. The jitter signal b indicates a signal whose phase changes at a predetermined fluctuation speed and within a predetermined fluctuation range with respect to a reference rectangular wave signal a as a reference signal to be transmitted. The amount is defined as the jitter amount, and the phase fluctuation speed is defined as the modulation frequency.

  The unit of the jitter amount (hereinafter also referred to as “phase modulation amount”) is indicated by a multiple of the period (unit interval: UI) of the reference rectangular wave signal a. For example, the 90 ° phase modulation amount is 0.25 UI, and the jitter amount in one cycle is 1 UI. As an apparatus for transmitting a jitter-modulated signal while changing the modulation frequency and phase modulation amount as needed to a system under test including a device under test (DUT) and the like and performing a jitter tolerance test, for example, A jitter generator disclosed in Patent Document 1 is known.

JP 2001-285043 A

  By the way, in the conventional jitter generator including Patent Document 1, it is desired that the modulation frequency and the phase modulation amount of the generated jitter signal b can be set arbitrarily. In the conventional jitter generator, when setting the modulation frequency and phase modulation amount, the numeric keypad is operated, for example, a numerical value is directly input to the input setting field of each parameter displayed on the display screen, or the slider is moved. And set a numerical value according to the operation.

  However, in situations where the modulation frequency and phase modulation amount must be set frequently as in the jitter transmission characteristics test of the system under test, the modulation frequency and phase modulation amount must be set each time. It was very complicated. In addition, in the direct input from the numeric keypad or the numerical setting by the slider, it is difficult to grasp the correspondence between the actually set value and the jitter settable value, so an intuitive setting method has been desired.

  Accordingly, the present invention has been made in view of the above-described problems, and jitter addition that enables simple and intuitive setting of the modulation frequency and phase modulation amount of jitter to be added to a signal to which jitter is to be added. An object of the present invention is to provide an apparatus and a jitter addition method.

In order to achieve the above object, a jitter adding apparatus according to claim 1 is a jitter adding apparatus 1 for adding arbitrarily set jitter to a target signal to be jitter-added.
A display unit 15 configured to display parameter graph information including two-dimensional graph data in which a coordinate axis is configured by two parameters of a phase modulation amount and a modulation frequency, and indicating a jitter setting possible range set for each device;
An operation unit 11 operated when selecting an arbitrary position within a jitter setting range of the parameter graph information with the pointer P displayed on the same screen on which the parameter graph information is displayed;
A control unit 13 for setting each parameter of jitter to be added to the target signal according to the coordinate position of the pointer;
It is provided with.

The jitter adding apparatus according to claim 2, wherein the jitter adding apparatus 1 adds arbitrarily set jitter to a target signal to be jitter added.
It consists of two-dimensional graph data whose coordinate axis is composed of two parameters of phase modulation amount and modulation frequency, parameter graph information indicating the jitter setting range set for each device, and the jitter setting range of the parameter graph information A display unit 15 for displaying a pointer P that is operated when an arbitrary position in the screen is selected;
The amount of movement of the pointer when the pointer is moved within the jitter settable range of the parameter graph information displayed on the display unit is output as pointer movement information, and the pointer is set within the jitter settable range. An operation unit 11 for outputting position determination information indicating that an arbitrary position within the jitter settable range is selected and determined,
The pointer position determination information indicating the coordinate position of the pointer detected from the position determination information from the operation unit is collated with the parameter graph information, and the phase modulation amount and the modulation frequency corresponding to the coordinate position of the pointer are set as jitter. A control unit 13 that outputs information,
A jitter adding unit 14 that generates jitter based on the jitter setting information from the parameter determination processing unit, adds the generated jitter to the target signal, and outputs the jitter;
It is provided with.

The jitter adding apparatus according to claim 3 is the jitter adding apparatus according to claim 2, wherein the control unit 13 includes:
Position information detection means 13a for outputting the coordinate position of the pointer as pointer position information based on the pointer movement information input from the operation unit 11 as the pointer P moves;
When the pointer position information from the position information detection means is input, the pointer position information is compared with the parameter graph information, and the phase modulation amount and modulation frequency based on the current coordinate position of the pointer are output as parameter information. Parameter discrimination processing means 13b,
The display unit 15 displays, on the display unit, a parameter display column 15a for displaying each parameter corresponding to the position of the pointer within the jitter setting range of the parameter graph information. The parameters in the respective parameter display fields are updated and displayed following the pointer movement trajectory based on parameter information input as the pointer moves.

The jitter addition method according to claim 4, wherein the jitter addition method is configured to add arbitrarily set jitter to a target signal to be jitter added.
A display step for displaying parameter graph information indicating a jitter setting possible range set for each device, comprising two-dimensional graph data in which a coordinate axis is configured by two parameters of a phase modulation amount and a modulation frequency;
An operation step operated when selecting an arbitrary position within a jitter setting range of the parameter graph information with the pointer P displayed on the same screen on which the parameter graph information is displayed;
A control step of setting each parameter of jitter to be added to the target signal according to the coordinate position of the pointer;
It is characterized by including.

The jitter addition method according to claim 5, wherein a jitter addition method for adding arbitrarily set jitter to a target signal as a jitter addition target is provided.
It consists of two-dimensional graph data whose coordinate axis is composed of two parameters of phase modulation amount and modulation frequency, parameter graph information indicating the jitter setting range set for each device, and the jitter setting range of the parameter graph information A display step for displaying a pointer P that is operated when an arbitrary position in the screen is selected;
The amount of movement of the pointer when the pointer is moved within the jitter settable range of the parameter graph information displayed on the display unit is output as pointer movement information, and the pointer is set within the jitter settable range. An operation step of outputting position determination information indicating that an arbitrary position within the jitter settable range has been selected and determined,
The pointer position determination information indicating the coordinate position of the pointer detected from the position determination information from the operation unit is collated with the parameter graph information, and the phase modulation amount and the modulation frequency corresponding to the coordinate position of the pointer are set as jitter. A control step to output as information;
A jitter adding step for generating jitter based on the jitter setting information from the parameter discrimination processing means and adding to the target signal for output;
It is characterized by including.

  According to the jitter adding apparatus of the present invention, the operator visually recognizes the parameter graph information displayed on the display unit and only moves the pointer by the operation unit, and the jitter is added to the target signal in two types of phase modulation amount and modulation frequency. Since the parameters can be set simultaneously within the jitter setting range, the jitter parameter setting operation can be performed easily and quickly.

  In addition, each parameter of jitter can be set intuitively while visually recognizing the parameter graph information on the display screen, so that the operability is further improved and even an operator unfamiliar with device operation can A desired jitter addition operation can be easily performed.

It is a schematic block diagram which shows the structure of the jitter addition apparatus which concerns on this invention. It is explanatory drawing which shows the example of a display of the parameter graph information in the same apparatus. It is explanatory drawing which shows the example of a display before the jitter setting in the same apparatus. It is explanatory drawing which shows the example of a display after the jitter setting in the same apparatus. The reference rectangle is a diagram showing the relationship between the signal and the jitter-modulated signal.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited by this embodiment, and all other forms, examples, operation techniques, etc. that can be implemented by those skilled in the art based on this form are included in the scope of the present invention. .

  First, the configuration of the jitter adding apparatus according to the present invention will be described with reference to FIG. The jitter adding apparatus 1 of this example transmits a signal with jitter added to a device under test (DUT) to be tested, for example, and determines whether or not the device under test correctly transmits a jitter signal. A modulation frequency (f) and phase modulation amount for a signal generated internally or externally (to be referred to as a “target signal”) that is provided on the transmission side in a test system that measures with an error rate measuring device A signal to which jitter with arbitrarily set parameters of (UI) is added is output.

  As shown in FIG. 1, the jitter adding apparatus 1 of this example includes an operation unit 11, a storage unit 12, a control unit 13, a jitter adding unit 14, and a display unit 15.

  The operation unit 11 moves the pointer P displayed on the display screen of the display unit 15 to specify the position of the pointer P on the display screen and select a setting item necessary for driving the device. Consists of devices. In this example, an example in which a mouse is used as the operation unit 11 will be described. When the parameter graph information stored in the storage unit 12 is displayed and expanded on the display screen, the operation unit 11 moves the pointer P displayed on the screen from the current position to an arbitrary position according to a predetermined operation. (For example, drag and drop), and the movement amount in the X direction and the Y direction accompanying this movement is output to the control unit 13 as pointer movement information.

  When the operation unit 11 performs an operation for selecting and determining the position of the pointer P (for example, a click operation at an arbitrary position on the display screen, a drop of the pointer P by drag and drop, etc.), Position determination information indicating that it has been determined is output to the control unit 13. Furthermore, by operating the waveform selection item displayed on the display unit 15 from the operation unit 11, it is possible to arbitrarily select a modulation waveform type (sine wave, triangular wave, square wave) of jitter to be added to the target signal.

  When displayed on the display unit 15, the storage unit 12 has parameters such as those shown in FIG. 2, for example, with the vertical axis (X axis) as the phase modulation amount and the horizontal axis (Y axis) as the modulation frequency. A plurality of parameters are stored for each device using parameter graph information including two-dimensional graph data in which the amount of change of each parameter according to the value of each parameter (phase modulation amount and modulation frequency) per pixel and the amount of movement of the pointer P is set. is doing. Also, the parameter graph information displays a jitter setting range (thick line in the figure) that is set for each device and indicates the range in which the phase modulation amount and modulation frequency in jitter can be set. Accordingly, the operator can arbitrarily set each parameter of jitter to be added to the target signal by moving the pointer P within the jitter setting range while visually checking the display screen.

  The control unit 13 includes a position information detection unit 13a, a parameter determination processing unit 13b, and a display control unit 13c, and performs drive control of each unit constituting the jitter adding apparatus 1.

  When the position information detecting means 13a receives the pointer movement information from the operation unit 11, the position information detecting means 13a detects the movement amount from the coordinate position before the movement of the pointer P on the display screen to the coordinate position after the movement. The coordinate position is output to the parameter discrimination processing means 13b as pointer position information. Since the pointer P moves following the operation from the operation unit 11, pointer movement information is input at any time while the operation unit 11 is operated, and pointer position information based on the movement information is output. .

  In addition, when the position determination information is input from the operation unit 11, the position information detection unit 13a outputs the coordinate position of the determined pointer P to the parameter determination processing unit 13b.

  When the pointer position information from the position information detection unit 13a is input, the parameter discrimination processing unit 13b collates with the parameter graph information stored in the storage unit 12 each time, and the phase modulation amount based on the current coordinate position of the pointer P is calculated. The modulation frequency is output as parameter information to the display control means 13c. Further, when the parameter position determination unit 13b receives the pointer position determination information from the position information detection unit 13a, the parameter determination processing unit 13b collates with the parameter graph information stored in the storage unit 12, and the phase based on the determined coordinate position of the pointer P Each parameter of the modulation amount and the modulation frequency is output to the display control means 13c and the jitter adding unit 14 as jitter setting information.

The display control means 13c generates a video signal based on various information (pointer position information, pointer position determination information, etc.) related to display control from the control unit 13, and outputs this signal to the display unit 15 for display.
Examples of display control in the display control unit 13c include control for displaying parameter graph information stored in the storage unit 12 on the display unit 15, display control for the pointer P based on pointer position information from the position information detection unit 13a, and parameter display. Display of column 15a, update display control of phase modulation amount and modulation frequency displayed in parameter display column 15a accompanying pointer movement, enlargement / reduction display of designated area in display contents of displayed parameter graph information, jitter to be added There are display control of a waveform selection item for selecting a modulation waveform type (sine wave, triangle wave, square wave), display control of a modulation waveform image corresponding to the selected modulation waveform type, and the like.

  The jitter adding unit 14 includes a D / A converter and a phase modulator, for example, adds jitter of a set parameter to a target signal arbitrarily set by an operator such as a clock signal or a test signal, It is output as a signal having a specified jitter amount (jitter added signal). Specifically, the jitter setting information input as a digital signal from the parameter discrimination processing means 13b is D / A converted, and the jitter of the parameter set by the operation unit 11 is generated based on the analog-converted modulation signal, and the target signal It is attached to.

  The display unit 15 is composed of a display device such as an LCD (Liquid Crystal Display), and displays display contents based on parameter graph information stored in the storage unit 12 based on the control of the display control unit 13c. The display contents displayed on the display unit 15 include, for example, the parameter graph information described above as shown in FIGS. 3 and 4, the pointer P for arbitrarily setting the jitter parameter within the jitter setting range, and the movement of the pointer P. A parameter display field 15a for displaying the phase modulation amount and modulation frequency corresponding to the position and a waveform selection item 15b for selecting the modulation waveform type of the jitter to be added are displayed. Since the parameter display field 15a is composed of a spin box, for example, when performing direct parameter input or fine adjustment, any numerical value can be input by operating the up and down keys of the parameter display field 15a. ing.

  Next, an example of the processing operation in the jitter adding apparatus 1 described above will be described with reference to FIGS. The following description is an example in which the present apparatus is employed in a jitter test system. A jitter-added signal in which a mouse is used as the operation unit 11 and a sine wave jitter is added to a clock signal that is an externally generated target signal. Is output to the device under measurement.

  First, as shown in FIG. 3, the operator activates the apparatus, selects parameter graph information corresponding to the device, and causes the display unit 15 to display the parameter graph information. Next, while confirming the jitter settable range on the display screen, the phase modulation amount and the modulation frequency of the jitter to be added to the target signal to which the jitter is added are set within the settable range.

  At this time, as shown in FIG. 3, the operator intuitively moves the pointer P on the display screen while dragging it in the predetermined direction with the mouse, and as shown in FIG. Drop with. The numerical values displayed in the parameter display column 15a for the parameters of the phase modulation amount and the modulation frequency are also updated and displayed following the movement trajectory of the pointer P that is moved when dragging and dropping. Thereby, the parameter of the jitter to be added to the target signal is set simultaneously within the jitter setting range.

  Then, jitter is generated based on the set jitter setting information, and the generated jitter is added to the clock signal and output to the device under test. The error rate measurement apparatus inputs the jitter modulated signal via the device under test. Measure whether the signal under test is correctly transmitted.

  As described above, the jitter adding apparatus 1 described above displays the parameter graph information on the display unit 15, and operates the pointer P with the operation unit 11 within the jitter settable range in the displayed parameter graph information. Set parameters to generate jitter. Then, jitter based on the set parameters is generated, and the generated jitter is added to the target signal and output.

  As a result, the operator can simultaneously view the two parameters of the phase modulation amount and the modulation frequency of the jitter added to the target signal only by moving the pointer P by the operation unit 11 while visually recognizing the parameter graph information displayed on the display unit 15. Therefore, the operation at the time of setting the jitter can be easily performed.

  In addition, each parameter of jitter can be set intuitively while visually recognizing the parameter graph information on the display screen, so even an operator unfamiliar with device operation can perform desired jitter addition work on the target signal. It can be done easily.

  By the way, although the example which used the mouse | mouth as a structure of the operation part 11 in the form mentioned above was demonstrated, the touch panel system is employ | adopted as a structure of the display part 15, and the stylus for touching the pointer P displayed on the display screen directly A configuration in which a fingertip is used as the operation unit 11 may be used. This makes it possible to set the jitter parameters more intuitively.

DESCRIPTION OF SYMBOLS 1 ... Jitter addition apparatus 11 ... Operation part 12 ... Memory | storage part 13 ... Control part (13a ... Position information detection means, 13b ... Parameter discrimination | determination processing means, 13c ... Display control means)
14 ... Jitter adding unit 15 ... Display unit (15a ... Parameter display column, 15b ... Waveform selection item)
P ... Pointer

Claims (5)

In a jitter adding apparatus (1) for adding arbitrarily set jitter to a target signal to be added with jitter,
A display unit (15) for displaying parameter graph information including two-dimensional graph data in which a coordinate axis is configured by two parameters of a phase modulation amount and a modulation frequency, and indicating a jitter settable range set for each device;
An operation unit (11) operated when selecting an arbitrary position within a jitter setting range of the parameter graph information with a pointer (P) displayed on the same screen on which the parameter graph information is displayed;
A control unit (13) for setting each parameter of jitter to be added to the target signal according to the coordinate position of the pointer;
A jitter adding apparatus comprising: In a jitter adding apparatus (1) for adding arbitrarily set jitter to a target signal to be added with jitter,
It consists of two-dimensional graph data whose coordinate axis is composed of two parameters of phase modulation amount and modulation frequency, parameter graph information indicating the jitter setting range set for each device, and the jitter setting range of the parameter graph information A display unit (15) for displaying a pointer (P) operated when selecting an arbitrary position in
The amount of movement of the pointer when the pointer is moved within the jitter settable range of the parameter graph information displayed on the display unit is output as pointer movement information, and the pointer is set within the jitter settable range. An operation unit (11) for outputting position determination information indicating that an arbitrary position within the jitter settable range has been selected and determined,
The pointer position determination information indicating the coordinate position of the pointer detected from the position determination information from the operation unit is collated with the parameter graph information, and the phase modulation amount and the modulation frequency corresponding to the coordinate position of the pointer are set as jitter. A control unit (13) that outputs information,
A jitter adding section (14) for generating jitter based on the jitter setting information from the parameter discrimination processing means and adding the generated jitter to the target signal;
A jitter adding apparatus comprising: The control unit (13)
Position information detection means (13a) for outputting the coordinate position of the pointer as pointer position information based on the pointer movement information input from the operation unit (11) as the pointer (P) moves;
When the pointer position information from the position information detection means is input, the pointer position information is compared with the parameter graph information, and the phase modulation amount and modulation frequency based on the current coordinate position of the pointer are output as parameter information. Parameter discrimination processing means (13b),
The display unit (15) displays on the display unit a parameter display field (15a) for displaying each parameter according to the position of the pointer within the jitter setting range of the parameter graph information, and further, the parameter determination 3. The jitter adding apparatus according to claim 2, wherein a parameter in each of the parameter display fields is updated and displayed following a movement locus of the pointer based on parameter information input as the pointer moves from a processing means. In a jitter addition method for adding arbitrarily set jitter to a target signal to be added with jitter,
A display step for displaying parameter graph information indicating a jitter setting possible range set for each device, comprising two-dimensional graph data in which a coordinate axis is configured by two parameters of a phase modulation amount and a modulation frequency;
An operation step operated when selecting an arbitrary position within a jitter setting range of the parameter graph information with a pointer (P) displayed on the same screen on which the parameter graph information is displayed;
A control step of setting each parameter of jitter to be added to the target signal according to the coordinate position of the pointer;
A method for adding jitter. In a jitter addition method for adding arbitrarily set jitter to a target signal to be added with jitter,
It consists of two-dimensional graph data whose coordinate axis is composed of two parameters of phase modulation amount and modulation frequency, parameter graph information indicating the jitter setting range set for each device, and the jitter setting range of the parameter graph information A display step for displaying a pointer (P) operated when selecting an arbitrary position in
The amount of movement of the pointer when the pointer is moved within the jitter settable range of the parameter graph information displayed on the display unit is output as pointer movement information, and the pointer is set within the jitter settable range. An operation step of outputting position determination information indicating that an arbitrary position within the jitter settable range has been selected and determined,
The pointer position determination information indicating the coordinate position of the pointer detected from the position determination information from the operation unit is collated with the parameter graph information, and the phase modulation amount and the modulation frequency corresponding to the coordinate position of the pointer are set as jitter. A control step to output as information;
A jitter adding step for generating jitter based on the jitter setting information from the parameter discrimination processing means and adding to the target signal for output;
A method for adding jitter.

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