JP5443290B2 - Error rate measuring apparatus and error rate measuring method - Google Patents

Description

  The present invention relates to an error rate measuring apparatus for measuring a bit error rate and a waveform of a signal under measurement output from a device under test for performing communication stipulated in a communication standard, and in particular, measuring at the time of measuring a bit error rate. Communicating from parameter values that set conditions, parameter values that set measurement conditions during waveform measurement, and filters that remove signal components other than multiple desired bands corresponding to each of multiple bit rates specified in the communication standard The present invention relates to an error rate measuring apparatus and an error rate measuring method for improving operability by matching parameter values for selecting a filter that matches a standard.

  In recent years, various digital wireless communication apparatuses are required to have a larger capacity transmission capability as the number of users increases and multimedia communication spreads. As an index for evaluating the quality of a digital signal in these digital wireless communication apparatuses, a bit error rate (Bit Error Rate) defined as a comparison between the number of received code errors and the total number of received data. )It has been known.

  In addition, a test signal including fixed data is transmitted to a device under test (Device Under Test) such as a photoelectric conversion component for performing communication defined by a communication standard to be tested, and input via the device under test. As an apparatus for detecting the error rate of a signal under measurement by comparing the signal under measurement with a reference signal as a reference and detecting the error rate of the signal under measurement, for example, an error rate measurement apparatus as disclosed in Patent Document 1 below is known. is there.

FIG. 8 is a schematic configuration diagram of an error rate measuring apparatus disclosed in Patent Document 1 below. As illustrated, the bit error measuring apparatus 100 includes a data storage unit 101 configured by a memory such as a RAM, a comparison data storage unit 102, a position information storage unit 103, and a signal transmission unit 104 configured by an integrated circuit or the like. , A signal reception unit 105, a synchronization detection unit 106, a comparison unit 107, a display control unit 108, a display device 109 such as a CRT or a liquid crystal display, and an operation unit 110 such as a keyboard. In the bit error measuring apparatus 100 that measures the error bit by comparing the data with the known data to be received from the measurement object 200, the comparison data storage unit 102 compares the received input data with the known data, Comparison data of a bit string including one or more detection bits detected under a predetermined detection condition is detected. The comparison unit 107 that sequentially stores the comparison data in the comparison data storage unit 102 and the respective bit strings obtained from the comparison data stored in the comparison data storage unit 102 with respect to the position according to a predetermined arrangement condition And a display control unit 108 that displays the display devices 109 side by side.
Further, conventionally, in addition to the configuration of the bit error measuring device 100, communication is performed from a waveform observing device 122 for observing the waveform of input data received from the measurement target 200 and a filter for removing signal components other than the desired band. A plurality of filters 121 conforming to the standard and a signal divider 120 for dividing the input data received from the measurement target 200 into two paths of the bit error measurement device 100 and the waveform observation device 122 are configured.

JP 2007-274474 A

  By the way, when the error rate of the device under test is measured using the error rate measuring device of Patent Document 1 described above, a waveform measuring device that measures a signal waveform such as an oscilloscope is used when an abnormality in the measurement result is found. The cause is investigated by measuring the waveform of the signal under test input from the device under test.

  As described above, when measuring the device under test using the error rate measuring device and the waveform measuring device, since the same signal under test input through the device under test is measured, the measurement conditions of each device It is necessary to make the parameter values to set the same. However, since each function is provided independently in the conventional apparatus, in order to perform measurement, parameter values for setting measurement conditions are set in each of the error rate measuring apparatus and the waveform measuring apparatus, and the desired bandwidth is set. It is necessary to confirm and set whether or not a plurality of filters matching the communication standard are matched from the filters for removing signal components other than those, and the setting work is complicated. For this reason, the operation becomes extremely complicated, and there is a problem that the optimum measurement cannot be performed due to forgotten setting or mistake.

  Also, depending on the user, there is an example of measuring the signal waveform with the waveform measuring device after measuring the error rate of the device under test with the error rate measuring device as described above. Development of a new apparatus having a waveform measuring function in a waveform measuring apparatus is desired.

Furthermore, filters that remove signal components other than the desired band are used in various fields. In particular, in the optical communication field, in the receivers such as the error rate measurement device and the waveform measurement device described above, signal noise component removal is performed. In order to prevent ringing, the use of a fourth-order Bessel-Thomson Low-Pass-Filter (hereinafter abbreviated as BT-LPF) having a cutoff frequency of 75% of the signal bit rate (signal communication speed) is a communication standard. It is prescribed. For example, ITU-T G.I. In 957, a fourth order Bessel LPF is defined as a characteristic of the reference receiver, and an error range of the frequency characteristic is defined. The signal bit rate and the cut-off frequency of BT-LPF are determined for each communication standard, not limited to the communication standard described above. For this reason, it is necessary to use BT-LPF in the receivers of various measuring apparatuses including the error rate measuring apparatus described above.
Since each measurement apparatus supports bit rates of various communication standards so that measurements can be performed at various frequencies, BT-LPFs are required for the types of bit rates of the communication standards.
In addition, since the communication standard requires BT-LPF characteristics as the characteristics of the entire receiver, it is necessary to design the entire receiving system, not the filter alone, for each receiving system (for each measuring device). Therefore, it is necessary to switch the BT-LPF according to the bit rate of the communication standard.

  Therefore, the present invention has been made in view of the above problems, and includes an error rate measurement function and a waveform measurement function, and is defined by a parameter value related to error rate measurement, a parameter value related to waveform measurement, and a communication standard. An object of the present invention is to provide an error rate measuring apparatus and an error rate measuring method capable of simplifying a setting operation by matching parameter values for selecting frequency characteristic correcting means corresponding to each of a plurality of bit rates. It is.

In order to achieve the above object, the error rate measuring apparatus according to claim 1 stipulates a signal under measurement output from a device under test (90) for performing communication stipulated in a communication standard in accordance with the communication standard. A frequency characteristic selection unit that includes a plurality of frequency characteristic correction units (12) that correct the frequency characteristics corresponding to each of the plurality of bit rates, and that selects any one of the plurality of frequency characteristic correction units (11) and
An error rate measuring unit (14) for measuring a bit error rate of the signal under measurement corrected by the selected frequency characteristic correcting unit;
A waveform measuring unit (15) for measuring the waveform of the signal under measurement corrected by the selected frequency characteristic correcting unit;
An operation input unit (20) for inputting parameter values for selecting the plurality of frequency characteristic correction units, setting measurement conditions of the error rate measurement unit, or setting measurement conditions of the waveform measurement unit; A parameter value of the frequency characteristic selection unit for selecting a plurality of frequency characteristic correction units, a parameter value for setting measurement conditions of the error rate measurement unit, and a measurement condition of the waveform measurement unit A parameter correspondence information storage unit (30) in which parameter correspondence information associated with parameter values is stored in advance as a table (31);
When the parameter value of any one of the frequency characteristic selection unit, the error rate measurement unit, and the waveform measurement unit is input to the operation input unit, based on the parameter correspondence information in the parameter correspondence information storage unit, the basis of the input parameter value, the control unit for setting other parameters values Tsu Naka is input (19),
It is provided with.

The error rate measurement device according to claim 2 is the error rate measurement device according to claim 1, wherein the parameter correspondence information includes at least a standard name of the communication standard,
The bit rate to be set in the error rate measurement unit and the waveform measurement unit defined in the communication standard;
Information for selecting the frequency characteristic correction unit corresponding to the bit rate is associated with the bit rate.
The error rate measurement apparatus according to claim 3, wherein the control unit is configured to select the frequency characteristic selection unit, the error rate measurement unit, and the waveform measurement. Each time the parameter value is input to the operation input unit, based on the parameter correspondence information in the parameter correspondence information storage unit, the parameter value was not input with reference to the input parameter value Other parameter values are set.

The error rate measuring device according to claim 4 is the error rate measuring device according to any one of claims 1 to 3, wherein a bit rate discriminating unit (40) for automatically discriminating a bit rate of the signal under measurement is provided. The control unit further determines the parameter value according to the bit rate determined by the bit rate determination unit, and sets the parameter values of the frequency characteristic selection unit, the error rate measurement unit, and the waveform measurement unit It is characterized by that.
The error rate measurement device according to claim 5 is the error rate measurement device according to any one of claims 1 to 4, wherein the parameter correspondence information and the frequency characteristic selection unit (11) are implemented. Only the mounted frequency characteristic correction unit can be selected by the operation input unit (20) from the mounting information of the plurality of frequency characteristic correction units (12).
The error rate measurement device according to claim 6 is the error rate measurement device according to any one of claims 1 to 5, wherein the signal under measurement is an optical signal, and is placed before the frequency characteristic selection unit. A photoelectric conversion unit (10) for converting the optical signal into an electrical signal is further provided.
The error rate measurement device according to claim 7 is the error rate measurement device according to any one of claims 1 to 6, wherein the frequency characteristic correction unit is a filter (50a, 50b) having a desired cutoff frequency. And an equalizer (51a, 51b) having a desired frequency correction characteristic.
The error rate measurement device according to claim 8 is the error rate measurement device according to any one of claims 1 to 7, wherein the frequency characteristic selection unit includes the plurality of frequency characteristic correction units, A high-frequency switching unit (52a, 52b) whose contacts are controlled to be opened and closed in order to switch the path of a high-frequency signal in order to select the frequency characteristic correction unit corresponding to the bit rate of the communication standard from among the frequency characteristic correction units. It is characterized by having.
The error rate measurement device according to claim 9 is the error rate measurement device according to any one of claims 1 to 8, wherein the parameter value input from the operation input unit is measured by the error rate measurement unit. If the parameter value for setting the condition or the parameter value for setting the measurement condition of the waveform measurement unit, whether the input parameter value corresponds to the plurality of frequency characteristic correction units or not The determination is made based on parameter correspondence information, and notification is performed when the parameter value does not correspond to any of the plurality of frequency characteristic correction units.
The error rate measurement method according to claim 10, wherein a signal under measurement output from a device under test for performing communication defined by a communication standard corresponds to each of a plurality of bit rates defined by the communication standard. A frequency characteristic correction step for correcting the frequency characteristic;
An error rate measurement step for measuring a bit error rate of the signal under measurement corrected in the frequency characteristic correction step;
An error rate measurement method comprising: a waveform measurement step for measuring a waveform of the signal under measurement corrected in the frequency characteristic correction step;
An operation input step for inputting each parameter value for setting a correction condition for the frequency characteristic correction step, setting a measurement condition for the error rate measurement step, or setting a measurement condition for the waveform measurement step;
The parameter value for the frequency characteristic correction step for setting the correction condition for the frequency characteristic correction step, the parameter value for setting the measurement condition for the error rate measurement step, and the measurement condition for the waveform measurement step are set. An information storage step of storing parameter correspondence information in association with parameter values for
When the parameter value of any one of the frequency characteristic correction step, the error rate measurement step, and the waveform measurement step is input in the operation input step, the parameter correspondence information in the parameter correspondence information storage step Based on the input parameter value, a control step for setting other parameter values not input ,
A measurement execution step of measuring at least one of the bit error rate measurement and the waveform measurement using the parameter value as the reference and the set parameter value;
It is characterized by including.

According to the error rate measuring apparatus of the present invention, the frequency characteristics corresponding to each of a plurality of bit rates defined by the error rate measuring unit, the waveform measuring unit, and the communication standard are selected to evaluate the characteristics of the device under test. At this time, based on the parameter correspondence information for associating and managing the necessary parameter values, other parameter values that were not input are set based on the input parameter values. It is possible to set parameter values of a plurality of measurement units and frequency characteristic selection units by value.
In addition, according to the error rate measuring apparatus of the present invention, every time a parameter value of any one of the frequency characteristic selection unit, the error rate measurement unit, and the waveform measurement unit is input to the operation input unit, the parameter correspondence information storage unit based on the parameter correspondence information, based on the input parameter values, since configured to set the other parameter values that have not been entered, even if you change the parameter value, change settings each time There is no need for confirmation work and usability is improved.

It is a schematic block diagram which shows the apparatus structure of the error rate measuring apparatus which concerns on this invention. (A)-(c) It is explanatory drawing which shows the example of a display structure of the setting item screen before the operation input in the apparatus. (A)-(c) It is explanatory drawing which shows the example of a display structure of the setting item screen after the operation input in the apparatus. It is a figure which shows the structural example of the table of the parameter corresponding | compatible information storage part in the same apparatus. It is a processing sequence figure showing processing operation at the time of parameter value input of the device. It is a processing sequence figure showing processing operation at the time of parameter value change of the device. It is a flowchart which shows the processing operation at the time of parameter value input of the same apparatus. It is a schematic block diagram which shows the apparatus structure of the conventional error rate measuring apparatus.

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, operational 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. .
[Device configuration]
First, the system configuration of the error rate measuring apparatus according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the error rate measuring apparatus 1 of this example is an apparatus for measuring an error rate of the device under test 90 and measuring a signal waveform, and includes a photoelectric conversion unit 10, a frequency characteristic selection unit 11, Frequency characteristic correction unit 12, signal division unit 13, error rate measurement unit 14, waveform measurement unit 15, frequency characteristic correction control unit 16, error rate measurement control unit 17, waveform measurement control unit 18, control unit 19, operation input unit 20 , A display unit 21, a parameter correspondence information storage unit 30, a table 31, a bit rate determination unit 40, filters 50a and 50b, equalizers 51a and 51b, and a high frequency switching unit 52.

  The error rate measuring unit 14 functions as a pulse pattern generator (PPG) that transmits a test signal having a predetermined pulse pattern to the device under test 90, and the transmitted test signal via the device under test 90. It has the function of an error rate detector (ED) that receives and measures the error rate. The error rate measurement unit 14 performs processing related to error rate measurement based on the parameter value set by the operation input unit 20 under the control of the error rate measurement control unit 17, and sends the obtained measurement result to the error rate measurement control unit 17. Output.

  The error rate measurement control unit 17 functions as application software for driving and controlling the error rate measurement unit 14.

  When the parameter value for setting the measurement condition of the error rate measurement unit 14 is input from the operation input unit 20 to the error rate measurement control unit 17, the parameter value for setting the measurement condition of the error rate measurement unit 14 is set. As a reference, in order to set the parameter value of the frequency characteristic selection unit 11 for selecting any one of the plurality of frequency characteristic correction units 12 and the parameter value for setting the measurement conditions of the waveform measurement unit 15, the reference The parameter value of the frequency characteristic selection unit 11 for selecting a plurality of frequency characteristic correction units 12 stored in advance in the parameter correspondence information storage unit 30 while outputting the parameter value of the error rate measurement unit 14 to the control unit 19 In addition, an inquiry signal for inquiring a parameter value for setting the measurement condition of the waveform measurement unit 15 is output to the control unit 19.

When the inquiry signal is input from the error rate measurement control unit 17, the control unit 19 outputs the parameter value of the reference error rate measurement unit 14 to the parameter correspondence information storage unit 30 and also to the parameter correspondence information storage unit 30. On the other hand, the parameter value of the frequency characteristic selection unit 11 for selecting any one of the plurality of frequency characteristic correction units 12 and the parameter value for setting the measurement conditions of the waveform measurement unit 15 are inquired.
The parameter correspondence information storage unit 30 is realized by storage means such as a semiconductor memory or a hard disk, and is configured, for example, in the form of a table shown in FIG. Each item of FIG. 4 includes “Filter” 80 corresponding to the frequency characteristic selection unit 11, “Bitrate Standard (standard name)” 82 and “Bitrate” 83 corresponding to the error rate measurement unit 14, and waveform measurement unit “Data Rate” 84 and “Clock Rate” 85 corresponding to 15.
Thus, the table 31 of the parameter correspondence information storage unit 30 includes the parameter values of the frequency characteristic selection unit 11 for selecting any one of the plurality of frequency characteristic correction units 12 and the measurement conditions of the error rate measurement unit 14. Is stored in advance associating the parameter value for setting the parameter value with the parameter value for setting the measurement condition of the waveform measurement unit 15. Note that “Filter Cutoff” 81 is shown for easy understanding of the specific cut-off frequency of the filter, but is shown in FIGS. 2 and 3 showing an example displayed on the display screen of the display unit 21. Not. However, “Filter Cutoff” 81 may be displayed on the display screens of FIGS. 2 and 3 so that the user can grasp the specific cutoff frequency of the filter.
For example, when “10 GbE FEC” is input from the operation input unit 20 to the “Filter” 80 corresponding to the frequency characteristic selection unit 11, “Bitrate Standard (standard name) corresponding to the error rate measurement unit 14. ) “82” is “10 GbE FEC”, “Bitrate” 83 is “11.095728 (Gbps)”, “Data Rate” 84 corresponding to the waveform measuring unit 15 is “11.095728 (Gbps)”, “Clock Rate” "85" is uniquely determined as "11.095728 (Gbps)". The table shown in FIG. 4 may be configured to be changeable by an external input / output unit (not shown). If configured to be changeable in this way, it is possible to easily and flexibly cope with future increases in communication standards and changes in existing communication standards.

  When the parameter value is queried from the control unit 19, the parameter correspondence information storage unit 30 selects one of the plurality of frequency characteristic correction units 12 corresponding to the parameter value of the error rate measurement unit 14 as a reference output from the control unit 19. The parameter value of the frequency characteristic selection unit 11 for selecting one of them and the parameter value for setting the measurement conditions of the waveform measurement unit 15 are extracted from the table 31, and each extracted parameter value is extracted from the frequency characteristic correction control unit. 16 and the waveform measurement controller 18 respectively.

The frequency characteristic correction control unit 16 sets its own parameter value to be the parameter value output from the parameter correspondence information storage unit 30 and outputs a setting completion signal indicating that the setting is completed to the control unit 19. Then, the frequency characteristic correction control unit 16 controls the frequency characteristic selection unit 11 to select the frequency characteristic correction unit 12 corresponding to the parameter value output from the parameter correspondence information storage unit 30.
The waveform measurement control unit 18 sets its own parameter value to be the parameter value output from the parameter correspondence information storage unit 30, and outputs a setting completion signal indicating that the setting has been completed to the control unit 19.
When receiving a setting completion signal from the frequency characteristic correction control unit 16 and the waveform measurement control unit 18, the control unit 19 sets the parameter values of the frequency characteristic correction control unit 16 and the waveform measurement control unit 18 to desired parameter values, respectively. The measurement permission signal for permitting the measurement start is output to the error rate measurement control unit 17 and the waveform measurement control unit 18 because it is determined that the measurement is ready.
When the error rate measurement control unit 17 and the waveform measurement control unit 18 receive the measurement permission signal from the control unit 19, they start error rate measurement or waveform measurement, respectively. Alternatively, after receiving the measurement permission signal from the control unit 19, the measurement may be started when a measurement start instruction is input from the operation input unit 20.

The waveform measuring unit 15 converts, for example, an analog measurement waveform such as a sampling oscilloscope into a digital signal and loads it into the memory as waveform data, and a waveform obtained by discretely sampling an event in which the voltage or current value changes with time. A function of reproducing and displaying a waveform image on the display screen based on the data is provided. The waveform measurement unit 15 performs processing related to waveform measurement based on the parameter value set by the operation input unit 20 under the control of the waveform measurement control unit 18, and outputs the obtained waveform data to the waveform measurement control unit 18. Yes.
The waveform measurement control unit 18 functions as application software for driving and controlling the waveform measurement unit 15.
The photoelectric conversion unit 10 includes, for example, a photodiode (PD), and converts an optical signal input from one input terminal 1a into an electric signal.
When the output signal of the device under test 90 input from the input terminal 1a is an electrical signal, the photoelectric conversion unit 10 is not necessary. However, when the output signal of the device under test is an optical signal, the front stage of the high frequency switching unit 52a. Is provided with a photoelectric conversion unit 10 that converts an optical signal into an electrical signal, and converts the signal under measurement into an electrical signal.
The high frequency switching unit 52 is configured by a high frequency relay or a high frequency switch corresponding to a high frequency of 26 GHz, for example. The high-frequency switching unit 52 includes an input-side high-frequency switching unit 52a provided in the previous stage of the frequency characteristic correcting unit 12 and an output-side high-frequency switching unit 52b provided in the subsequent stage of the frequency characteristic correcting unit 12. Are controlled by the frequency characteristic correction control unit 16 in conjunction with each other.
In the frequency characteristic correction unit 12, a plurality of sets of filters 50a and 50b and equalizers 51a and 51b are connected in parallel between the input-side high-frequency switching unit 52a and the output-side high-frequency switching unit 52b. The plurality of sets of filters 50a and 50b and equalizers 51a and 51b correspond to the bit rates of the respective communication standards defined by the communication standards.
The filters 50a and 50b are made of, for example, a low-pass filter, and attenuate and block a frequency signal higher than a specific threshold, and pass only a low-frequency signal as a signal.
The equalizers 51a and 51b are composed of, for example, high-pass filter semiconductor resistors and capacitors arranged before and after the filters 50a and 50b, and the resistance values of the semiconductor resistors can be varied to satisfy the communication standard using the filters 50a and 50b. And adjust so that there is no deterioration in characteristics due to the high-frequency switching unit 52 (high-frequency relay or high-frequency switch), cable loss, the characteristics of the photoelectric conversion unit (PD) 10 being used, and the signal dividing unit 13. Yes.

  The signal dividing unit 13 is composed of a divider that divides a signal under measurement input via the device under test 90 into a predetermined path. When the signal division unit 13 performs measurement by the error rate measurement unit 14 and the waveform measurement unit 15 under the control of the control unit 19, the signal division unit 13 detects the signal under measurement from the device under test 90 and detects the error rate of the error rate measurement unit 14. It is divided into two paths to the device and the waveform measuring unit 15. When measuring the device under test 90 using only the error rate measuring unit 14, the signal dividing unit 13 outputs only the measured signal to the error rate measuring unit 14 without dividing the signal under measurement, and only the waveform measuring unit 15. When measuring the device under test 90, the signal under measurement is output only to the waveform measuring section 15 without being divided.

  The operation input unit 20 is configured by a touch panel including a touch sensor for detecting a contact position by a contact operation on an input surface corresponding to the display screen of the display unit 21, for example. The operation input unit 20 touches the position of a specific item in the setting item screen displayed on the display unit 21 with a finger, a stylus, or the like, and the position detected by the touch sensor on the screen and the position of the item. And outputs an item selection signal to the control unit 19 for executing the function assigned to each item.

  The display unit 21 includes a display device such as a liquid crystal display or a CRT. Based on the display control of the control unit 19, the setting item screen related to the error rate measuring unit 14 and the setting item screen related to the waveform measuring unit 15 are displayed and the error rate is measured. Display of measurement results obtained by the unit 14 and the waveform measuring unit 15, selection setting of the frequency characteristic correction control unit 16, communication standard names corresponding to the frequency characteristic correction unit 12, etc., driving of the error rate measuring apparatus 1 and various controls Display contents are displayed.

Here, referring to FIGS. 2 and 3, the setting item screen related to the error rate measuring unit 14 displayed on the display screen of the display unit 21, the setting item screen related to the waveform measuring unit 15, and the setting item related to the frequency characteristic selecting unit 11. A screen display example and an input operation example will be described. The illustrated setting item screen is a display example in an apparatus configuration including one error rate measuring unit 14 and one waveform measuring unit 15, and only the minimum necessary setting items for driving the error rate measuring apparatus 1 are shown. Is displayed, and a screen configuration in which setting items desired by the user are arbitrarily added in accordance with the specifications, configuration contents, usage environment, and the like of the apparatus can be used.
In FIG. 2, parameters of any one of the frequency characteristic selection unit 11, the error rate measurement unit 14, and the waveform measurement unit 15 are input to the operation input unit 20 of the error rate measurement apparatus 1 of the present invention. The previous state is shown.

  The setting item screen in the error rate measuring apparatus 1 of this example includes “Bit Rate” 60 and “Data Pattern” 63 mainly used in the error rate measuring unit 14 as shown in FIG. 2A, and FIG. As shown in FIG. 2, “Data Clock Rate” 65 and “Pattern Length” 69 mainly used in the waveform measurement unit 15, and “Filter Select” 71 mainly used in the frequency characteristic selection unit 11 as shown in FIG. The parameter value input items and the selection items by the operation input unit 20 are respectively displayed.

More specifically, as a parameter value input item by the operation input unit 20, “Bit Rate Standard” 61 which is the standard name of the communication standard is transmitted in the “Bit Rate” 60 column of FIG. There is an item of “Bitrate” 62 for inputting a bit rate which is the number of bits to be processed, and a data pattern of data such as PRBS7 which is one of pseudo random codes is input in the column of “Data Pattern” 63 There is an item “Pattern” 64 to be set, and an arbitrary value can be set by the user.
In addition, as a parameter value input item by the operation input unit 20, a “Data Clock Rate” 65 column in FIG. 2B is used to input a data rate that is the number of bits transmitted (processed) per unit time. There is an item of “Rate” 66 and “Clock Rate” 67 for inputting the clock rate which is the operating frequency of the clock signal, and “Acquire Clock Rate” for automatically measuring the clock rate internally as an auxiliary function for inputting the clock rate. There are 68 items, and any value can be set by the user.

FIG. 3 shows that the parameters of any one of the frequency characteristic selection unit 11, the error rate measurement unit 14, and the waveform measurement unit 15 are input to the operation input unit 20 of the error rate measurement apparatus 1 of the present invention. The later state is shown.
In the illustrated screen configuration example, the parameter value “10 GbE FEC” is input from the operation input unit 20 to the parameter value of any one unit, for example, the “Filter” 72 of the frequency characteristic selection unit 11 in FIG. When input, based on the information in the table 31 of the parameter correspondence information storage unit 30, the error rate at which the parameter value was not input on the basis of the parameter value “10 GbE FEC” of the frequency characteristic selection unit 11 to which the parameter value was input The parameter values of the measurement unit 14 and the waveform measurement unit 15 are set to values corresponding to the parameter values of the frequency characteristic selection unit 11 to which the parameter values have been input as shown in FIGS. 3 (a), 3 (b) and 3 (c). It is the structure to do. That is, based on the information in the table 31 in accordance with the parameter value “10 GbE FEC” of “Filter” 72 in FIG. 3C, “Data Rate” 66 is changed to “11.095728” Gbps in FIG. The parameter value “10 GbE FEC” set in the “Data Rate” 66 of FIG. 3B and each item of FIG. 3A is similarly input to the “Filter” 72 of FIG. "Is set to match. The parameter value of “Length” 70 in FIG. 3B may be configured not to be set based on the information in the table 31. This is because the parameter values of “Data Rate” 66 and “Clock Rate” 67 are indispensable setting items, but the parameter value of “Length” 70 is not an indispensable setting item depending on the measurement content desired by the user. This is because the configuration may be such that the user can make any setting as necessary.
The parameter values of “Bit Rate” 62 in FIG. 3A and “Data Rate” 66 and “Clock Rate” 67 in FIG. 3B are configured to be numerically input using a numeric keypad (not shown), for example. May be.
Further, when a parameter value is input to any one of “Bit Rate” 62 in FIG. 3A, “Data Rate” 66, and “Clock Rate” 67 in FIG. It is determined by referring to the table 31 whether or not it corresponds to any of the plurality of frequency characteristic correction units 12, and when it does not correspond to any of them, an error message is displayed on the display unit 21 and sound output by an acoustic means (not shown) is performed. Alternatively, notification may be performed by external output means (not shown).
By configuring in this way, it is confirmed that any one of the parameter values of “Bit Rate” 62, “Data Rate” 66, and “Clock Rate” 67 does not correspond to any of the plurality of frequency characteristic correction units 12. It is possible for the user to recognize and to prevent erroneous measurement due to numerical input of parameter values not corresponding to the frequency characteristic correction unit 12.
Further, only the mounted frequency characteristic correction unit 12 is input from the parameter correspondence information stored in the table 31 and the mounting information of the plurality of frequency characteristic correction units 12 currently mounted in the frequency characteristic selection unit 11. You may comprise so that it can select in the part 20. FIG.
Specifically, for example, each frequency characteristic correction unit 12 having a different frequency characteristic is provided with a connector for electrically connecting to the frequency characteristic selection unit 11, and each frequency characteristic correction unit 12 has a self- The ID indicating the frequency characteristics of the device and the ID indicating the corresponding communication standard are stored in advance using the semiconductor memory or the like as the mounting information. The frequency characteristic selection unit 11 acquires an ID or the like as mounting information via a connector, and detects what frequency correction unit 12 or the frequency correction unit 12 of the corresponding communication standard is mounted.
With this configuration, selection of the frequency characteristic correction unit 12 that is not mounted can be prevented in advance, the operability is improved, and the frequency item on which the selection item of the frequency characteristic correction unit 12 on the display unit 21 is mounted. Only the characteristic correction unit 12 is provided, and visibility is improved.

  The control unit 19 is composed of, for example, a microcomputer such as a CPU, ROM, or RAM. The control unit 19 controls the signal division of the signal division unit 13, and sets the frequency characteristic selection unit 11, the error rate measurement unit 14, and the waveform measurement unit 15 related to parameter values. In addition to various display controls when displaying item screens and measurement results, and control related to processing operations in accordance with item selection signals from the operation input unit 20, drive control of each unit constituting the error rate measuring apparatus 1 is performed.

  Further, when the parameter value is inquired from the error rate measurement control unit 17, the control unit 19 outputs the parameter value of the reference error rate measurement unit 14 and performs a plurality of frequency characteristic corrections on the parameter correspondence information storage unit 30. Queries the parameter value of the frequency characteristic selection unit 11 for selecting one of the units 12 and the parameter value for setting the measurement conditions of the waveform measurement unit 15.

  Further, when the control unit 19 receives a setting completion signal from the frequency characteristic correction control unit 16 and the waveform measurement control unit 18, the parameter values of the frequency characteristic correction control unit 16 and the waveform measurement control unit 18 are set to desired parameters. It is determined that the value has been reached, and a measurement permission signal for permitting the measurement start is output to the error rate measurement control unit 17 and the waveform measurement control unit 18 assuming that preparation for the measurement start is complete.

Similarly, when the parameter value is inquired from the waveform measurement control unit 18, the control unit 19 outputs the parameter value of the waveform measurement unit 15 as a reference, and a plurality of frequency characteristic correction units to the parameter correspondence information storage unit 30. The parameter value of the frequency characteristic selection unit 11 for selecting any one of 12 and the parameter value for setting the measurement conditions of the error rate measurement unit 14 are inquired.
Similarly, when the control unit 19 receives the setting completion signal from the frequency characteristic correction control unit 16 and the error rate measurement control unit 17, the parameter values of the frequency characteristic correction control unit 16 and the error rate measurement control unit 17 are respectively set. It is determined that the desired parameter value has been reached, and a measurement permission signal for permitting measurement start is output to the error rate measurement control unit 17 and the waveform measurement control unit 18 as preparation for measurement start is completed.

The control unit 19 inputs the parameter value of any one of the frequency characteristic selection unit 11, the error rate measurement unit 14, or the waveform measurement unit 15 (for example, the frequency characteristic selection unit 11) to the operation input unit 20. Each time the parameter value is not input based on the parameter value of the part (for example, the frequency characteristic selection unit 11) to which the parameter value is input based on the table 31 of the parameter correspondence information storage unit 30 The parameter value of the rate measuring unit 14 or the waveform measuring unit 15) is set to a value corresponding to the parameter value of the part to which the parameter value is input (for example, the frequency characteristic selecting unit 11).
[Processing operation]
Next, a series of processing operations relating to the measurement of the device under test 90 in the error rate measuring apparatus 1 described above will be described with reference to FIGS. Here, the signal under measurement output from the device under test 90 is input to the error rate measurement unit 14 via the frequency characteristic selection unit 11, and the signal under measurement output from the device under test 90 at the error rate measurement unit 14. After measuring the error rate, the waveform measurement unit 15 measures the waveform and inputs a parameter value from the item setting screen of the error rate measurement unit 14 (FIG. 5). A processing operation example (FIG. 6) when the parameter value is changed will be described. The display configuration shown in FIGS. 3 and 4 is used as the display configuration of the setting item screen used when inputting and changing parameter values.
(Processing when entering parameter values)
First, the processing operation at the time of inputting a parameter value will be described with reference to FIG. The user inputs parameter values in the error rate measuring apparatus 1 from the operation input unit 20, and inputs parameter values in various setting items of the error rate measuring unit 14 (ST1). Next, based on the input parameter value, the error rate measurement control unit 17 outputs the parameter value of the reference error rate measurement unit 14 to the control unit 19 and outputs an inquiry signal to the control unit 19 (ST2 ). Next, when an inquiry signal is input from the error rate measurement control unit 17, the control unit 19 selects a plurality of frequency characteristic correction units 12 stored in advance in the parameter correspondence information storage unit 30. An inquiry signal for inquiring 11 parameter values and parameter values for setting the measurement conditions of the waveform measurement unit 15 is output to the parameter correspondence information storage unit 30 (ST3).

When the parameter value is queried from the control unit 19, the parameter correspondence information storage unit 30 selects one of the plurality of frequency characteristic correction units 12 corresponding to the parameter value of the error rate measurement unit 14 as a reference output from the control unit 19. The parameter value of the frequency characteristic selection unit 11 for selecting one of them and the parameter value for setting the measurement conditions of the waveform measurement unit 15 are extracted from the table 31, and each extracted parameter value is extracted from the frequency characteristic correction control unit. 16 and the waveform measurement controller 18 (ST4).
The frequency characteristic correction control unit 16 sets its own parameter value to be the parameter value output from the parameter correspondence information storage unit 30 (ST5). Next, a setting completion signal indicating that the setting has been completed is output to the control unit 19 (ST6). Then, the frequency characteristic correction control unit 16 controls the frequency correction selection unit 11 to select the frequency characteristic correction unit 12 corresponding to the parameter value output from the parameter correspondence information storage unit 30 (ST7).
The waveform measurement control unit 18 sets its own parameter value to be the parameter value output from the parameter correspondence information storage unit 30 (ST8). A setting completion signal indicating completion of the setting is output to the control unit 19 (ST9).
When receiving a setting completion signal from the frequency characteristic correction control unit 16 and the waveform measurement control unit 18, the control unit 19 sets the parameter values of the frequency characteristic correction control unit 16 and the waveform measurement control unit 18 to desired parameter values, respectively. If it is determined that the measurement is ready, a measurement permission signal for permitting the measurement start is output to the error rate measurement control unit 17 and the waveform measurement control unit 18 (ST10).
When receiving the measurement permission signal from the control unit 19, the error rate measurement control unit 17 and the waveform measurement control unit 18 respectively start error rate measurement or waveform measurement (ST11, ST12). Alternatively, after receiving the measurement permission signal from the control unit 19, the measurement may be started when a measurement start instruction is input from the operation input unit 20.
(Processing when changing parameter values)
Next, the processing operation when changing the parameter value will be described with reference to FIG. The user changes the parameter value in the error rate measuring apparatus 1 from the operation input unit 20, and changes the parameter value in various setting items of the error rate measuring unit 14 (ST21). Next, based on the changed parameter value, the error rate measurement control unit 17 outputs the parameter value of the reference error rate measurement unit 14 to the control unit 19 and outputs a parameter change signal to the control unit 19 ( ST22). Next, when the parameter change signal is input from the error rate measurement control unit 17, the control unit 19 selects a frequency characteristic for selecting a plurality of frequency characteristic correction units 12 stored in advance in the parameter correspondence information storage unit 30. An inquiry signal for inquiring the parameter value of the unit 11 and the parameter value for setting the measurement conditions of the waveform measuring unit 15 is output to the parameter correspondence information storage unit 30 (ST23).

Hereinafter, the operation from ST24 to ST32 is the same as the operation from ST4 to ST12 in FIG.
Next, a processing method when inputting parameter values will be described with reference to FIG. First, to set the parameter value for the frequency characteristic correction step for setting the correction condition for the frequency characteristic correction step, the parameter value for setting the measurement condition for the error rate measurement step, and the measurement condition for the waveform measurement step Is stored in advance in the table as parameter correspondence information (S201).
Next, it is detected whether or not the parameter value of any one of the frequency characteristic correction step, the error rate measurement step, and the waveform measurement step is input (S202).
When the parameter value of any one of the steps is input, it is specified which parameter value is input in the step in which the parameter value is input, and the parameter value is set as the reference parameter value (S203). ).
Next, the parameter correspondence information stored in S201 is referred to, and a parameter value other than the reference parameter value corresponding to the reference parameter value is specified based on the parameter correspondence information (S204).
Next, the parameter value other than the reference parameter value, that is, the parameter value of the step in which no parameter value is input is set to a value corresponding to the reference parameter value (S205).
Next, it is detected whether or not there is an operation input for measurement execution in at least one of the error rate measurement step and the waveform measurement step (S206).
When an operation input for measurement execution is detected, at least one of bit error rate measurement and waveform measurement is performed using the reference parameter value and the parameter value set to the value corresponding to the reference parameter value. Measurement is performed (S207).

  By the way, although the touch panel was adopted as the configuration of the operation input unit 20 in the above-described embodiment and the user performed an input operation with a finger or a stylus, the present invention is not limited to this. Input / change of parameter values based on an external trigger from an external input device, such as operating a hard key such as a designated operation key or numeric keypad, or operating a soft key displayed on the display unit 21 with a pointing device such as a mouse. It can also be set as the structure which performs.

In addition, the parameter value inquiry method by the control unit 19 has been described as a configuration in which the parameter value inquiry is triggered by the input of the parameter value setting signal from the parameter value setting side, but is not limited thereto. In other words, the control unit 19 inquires each parameter value of the error rate measurement control unit 17, the waveform measurement control unit 18, and the frequency characteristic correction control unit 16 at a predetermined period, and controls each of the inquired parameter values. It is also possible to use a configuration in which only the parameter values that need to be set are output to the frequency characteristic correction control unit 16. In this case, the control unit 19 receives the inquiry signal output from any one of the error rate measurement control unit 17, the waveform measurement control unit 18, and the frequency characteristic correction control unit 16 until the measurement of the device under test 90 is completed. In the meantime, the parameter values may be inquired and output to each unit at a predetermined cycle.
Further, a bit rate discriminating unit 40 that automatically measures the clock rate internally is added as an auxiliary function to be input, and the control unit 19 is included in the parameter correspondence information storage unit 30 based on the bit rate discriminated by the bit rate discriminating unit 40. The table 31 is queried to determine the parameter value according to the clock rate of the signal under measurement output from the device under test 90, that is, the bit rate of the signal under measurement, and the frequency characteristic selection unit 11, error rate measurement unit 14 and the parameter values of the waveform measuring unit 15 may be set.
For example, when “Acquire Clock Rate” 68 in FIG. 2B is selected as “Set”, the clock rate of the signal under measurement output from the device under test 90 is not included in the bit rate determination unit 40 (not shown). Measurement is performed using a known clock recovery means, and the measured clock rate is automatically set to “Clock Rate” 67 in FIG. 3B, and the frequency characteristic selection unit 11 is based on the parameter value of “Clock Rate” 67. The parameter values of the error rate measurement unit 14 and the waveform measurement unit 15 may be set.

DESCRIPTION OF SYMBOLS 1 ... Error rate measuring device 1a ... Input terminal 10 ... Photoelectric conversion part 11 ... Frequency characteristic selection part 12 ... Frequency characteristic correction part 13 ... Signal division part 14 ... Error rate measurement part 15 ... Waveform measurement part 16 ... Frequency characteristic correction control part DESCRIPTION OF SYMBOLS 17 ... Error rate measurement control part 18 ... Waveform measurement control part 19 ... Control part 20 ... Operation input part 21 ... Display part 30 ... Parameter corresponding | compatible information storage part 31 ... Table 40 ... Bit rate discrimination | determination part 50a, 50b ... Filter 51a, 51b ... Equalizers 52a, 52b ... High frequency switching unit 60 ... Bit Rate
61 ... Bitrate Standard (standard name)
62 ... Bitrate
63 ... Data Pattern
64 ... Pattern
65 ... Data Clock Rate
66 ... Data Rate
67… Clock Rate
68 ... Acquire Clock Rate
69 ... Pattern Length
70 ... Length
71 ... Filter Select
72 ... Filter
80 ... Filter (parameter in the table)
81 ... Filter Cutoff (parameter in the table)
82 ... Bitrate Standard (standard name) (parameter in table)
83 ... Bitrate (parameter in the table)
84 ... Data Rate (parameter in the table)
85 ... Clock Rate (parameter in table)
90: Device under test

Claims (10)

A plurality of frequencies for correcting a signal under measurement output from a device under test (90) for performing communication defined by a communication standard to frequency characteristics corresponding to each of a plurality of bit rates defined by the communication standard A frequency characteristic selection unit (11) having a characteristic correction unit (12), and selecting any one of the plurality of frequency characteristic correction units;
An error rate measuring unit (14) for measuring a bit error rate of the signal under measurement corrected by the selected frequency characteristic correcting unit;
A waveform measuring unit (15) for measuring the waveform of the signal under measurement corrected by the selected frequency characteristic correcting unit;
An operation input unit (20) for inputting each parameter value for selecting the plurality of frequency characteristic correction units, setting measurement conditions of the error rate measurement unit, or setting measurement conditions of the waveform measurement unit;
To set parameter values of the frequency characteristic selection unit for selecting the plurality of frequency characteristic correction units, parameter values for setting measurement conditions of the error rate measurement unit, and measurement conditions of the waveform measurement unit A parameter correspondence information storage unit (30) in which parameter correspondence information in association with the parameter values is stored in advance as a table (31);
When the parameter value of any one of the frequency characteristic selection unit, the error rate measurement unit, and the waveform measurement unit is input to the operation input unit, based on the parameter correspondence information in the parameter correspondence information storage unit, the basis of the input parameter value, the control unit for setting other parameters values Tsu Naka is input (19),
An error rate measuring apparatus comprising: The parameter correspondence information includes at least a standard name of the communication standard,
The bit rate to be set in the error rate measurement unit and the waveform measurement unit defined in the communication standard;
2. The error rate measuring apparatus according to claim 1, wherein information for selecting the frequency characteristic correction unit corresponding to the bit rate is associated. Each time the parameter value of any one of the frequency characteristic selection unit, the error rate measurement unit, and the waveform measurement unit is input to the operation input unit, the control unit performs the parameter of the parameter correspondence information storage unit. 3. The error rate measuring apparatus according to claim 1, wherein other parameter values that are not input are set based on the input parameter values based on correspondence information. . A bit rate discriminating unit (40) for automatically discriminating the bit rate of the signal under measurement is further provided, and the control unit determines the parameter value according to the bit rate discriminated by the bit rate discriminating unit to determine the frequency 4. The error rate measuring apparatus according to claim 1, wherein parameter values of a characteristic selecting unit, the error rate measuring unit, and the waveform measuring unit are set. 5. From the parameter correspondence information and the mounting information of the plurality of frequency characteristic correction units (12) mounted in the frequency characteristic selection unit (11), only the frequency characteristic correction unit mounted is changed to an operation input unit ( The error rate measuring apparatus according to any one of claims 1 to 4, wherein the error rate measuring apparatus is selectable in 20). The signal under measurement is an optical signal, and further includes a photoelectric conversion unit (10) for converting the optical signal into an electric signal before the frequency characteristic selection unit. The error rate measuring apparatus according to any one of the above. The frequency characteristic correction unit includes a filter (50a, 50b) having a desired cutoff frequency and an equalizer (51a, 51b) having a desired frequency correction characteristic. The error rate measuring apparatus according to any one of claims 6 to 6.   The frequency characteristic selection unit includes the plurality of frequency characteristic correction units, and selects a frequency characteristic correction unit corresponding to the bit rate of the communication standard from the plurality of frequency characteristic correction units. The error rate measuring device according to any one of claims 1 to 7, further comprising a high-frequency switching unit (52a, 52b) that is controlled to be opened and closed in conjunction with each other to switch between the two. The parameter value input from the operation input unit is a parameter value for setting the measurement condition of the error rate measurement unit or a parameter value for setting the measurement condition of the waveform measurement unit The parameter value enteredIs determined based on the parameter correspondence information, and a notification is made when the parameter value does not correspond to any of the plurality of frequency characteristic correction units. The error rate measuring apparatus according to claim 1, wherein: A frequency characteristic correction step for correcting a signal under measurement output from a device under test for performing communication defined in a communication standard to a frequency characteristic corresponding to each of a plurality of bit rates defined in the communication standard;
An error rate measurement step for measuring a bit error rate of the signal under measurement corrected in the frequency characteristic correction step;
An error rate measurement method comprising: a waveform measurement step for measuring a waveform of the signal under measurement corrected in the frequency characteristic correction step;
An operation input step for inputting each parameter value for setting a correction condition for the frequency characteristic correction step, setting a measurement condition for the error rate measurement step, or setting a measurement condition for the waveform measurement step;
The parameter value for the frequency characteristic correction step for setting the correction condition for the frequency characteristic correction step, the parameter value for setting the measurement condition for the error rate measurement step, and the measurement condition for the waveform measurement step are set. An information storage step of storing parameter correspondence information in association with parameter values for
When the parameter value of any one of the frequency characteristic correction step, the error rate measurement step, and the waveform measurement step is input in the operation input step, the parameter correspondence information in the parameter correspondence information storage step Based on the input parameter value, a control step for setting other parameter values not input ,
A measurement execution step of measuring at least one of the bit error rate measurement and the waveform measurement using the parameter value as the reference and the set parameter value;
An error rate measurement method comprising:

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