JPH05260111A - Communication equipment - Google Patents

Abstract

PURPOSE:To easily observe the reception quality by accurately displaying the quality 6f reception data on a low-resolution display device. CONSTITUTION:Data from a line are transferred to a MODEM part 202 through a line interface 201 and demodulated in this part 202 to obtain a base band signal for in-phase and orthogonal components. The distortion component due to the line of the base band signal is eliminated by an equalizer 100, and the equalization residual error is eliminated by a discriminator 101. A square error E<2> and an absolute value phase error ¦thetae¦ are calculated based on the output of the equalizer and that of the discriminator, and they are quantized by quantizers 150 and 151 for the purpose of processing them into such a range that they can be displayed on the low-resolution display device, and they are displayed on a display device 303.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device for displaying the reception quality of received data.

[0002]

2. Description of the Related Art With the recent development of information communication technology, higher-speed data transmission has become possible, and various communication devices for realizing this have appeared. For example, as a method of this high speed data transmission, CCITT Recommendation V. Two
7 ter, V.I. 29, V.I. There are three-phase modulation (PSK) and quadrature amplitude modulation (QAM) indicated by 33 and the like. And
The core of data transmission using such a modulation method is a modem (modem). In a transmission system having this modem, a so-called eye pattern has been conventionally used as a means for observing the performance of the modem itself and the influence of noise and distortion due to the transmission path.

Generally, by observing the eye pattern, it is possible to understand the performance of the modem such as the influence on the data on the transmission path and the extent to which the modem absorbs the influence. Therefore, observation of an eye pattern is used as a means of performance evaluation at the time of maintenance of a communication device (for example, facsimile, computer, etc.) including such a modem. FIG. 14 shows a configuration example of conventional eye pattern observation, in which the output signal of an equalizer for compensating for distortion on the transmission path, which is the heart of the modem receiving section, is observed. Normally, the inside of the modem is DSP (Digital
If the transmission line is analog, Digital-Analog (D / A) conversion is performed at the modem transmission section and Analog-Digital (A / D) conversion is performed at the modem reception section. To do.

In FIG. 14, an equalizer 100 removes the influence of distortion due to a transmission line from an input signal to obtain an original transmission signal, and its output signal is an equalizer 100.
In order to remove the effects of noise that could not be removed by
The determining unit 101 determines that the point is normal. The eye pattern is for observing this equalizer output signal (decision device input signal). The in-phase component and quadrature component of the above signal, which are digital signals, are converted into analog signals by the D / A converters 102 and 103. After conversion, the oscilloscope 104 observes the waveform.

Therefore, conventionally, in order to observe the above-mentioned eye pattern, a serviceman carries an oscilloscope, which is a waveform observer, and observes the eye pattern for performance evaluation at a site where a communication device is installed. But,
Since it takes time to connect and observe, a proposal has been made to use a display panel (for example, LCD) provided in a communication device for displaying set values of system data of the device as an eye pattern display. There is. In other words, by using such a display board, eye pattern observation becomes easy and troubles can be dealt with more quickly.

[0006]

However, since the eye pattern usually has a very complicated shape,
A high resolution display device is required to display this. This is an indispensable condition when trying to understand the cause of pattern dispersion. Also, in recent years, the data transmission speed has been dramatically increased, and the number of eye patterns has also increased exponentially. Therefore, in order to display such an eye pattern, a display with higher resolution is required, and the display in most communication devices only has the function of displaying alphabets, numbers, and katakana. There is a problem that an eye pattern having such a complicated waveform cannot be displayed sufficiently. Even if the eye pattern can be displayed by the above method, it is not possible to grasp the cause of the dispersion of the pattern, and conversely, providing the communication device with a high-resolution display leads to an increase in the cost of the device. There's a problem.

[0007]

[Means for Solving the Problems] and

The present invention has been made for the purpose of solving the above-mentioned problems, and has the following structure as one means for solving the above-mentioned problems. That is, the invention according to claim 1 transmits / receives data through the accommodation line, and displays equalizing means for removing the influence of noise or the like on the received data by the line, and the set value unique to the device. And a display unit for displaying the phase of the received data based on the output of the equalizing unit and the first computing unit for calculating the noise variance of the received data based on the output of the equalizing unit. Second calculating means for calculating an error dispersion degree, and means for displaying the noise dispersion degree and the phase error dispersion degree on the display means so that the noise dispersion degree and the phase error dispersion degree are orthogonal to each other. With.

Further, the invention according to claim 4 transmits / receives data through the accommodating line and eliminates the influence of noise or the like on the received data by the line, and a set value specific to the device. In a communication device including a display unit for displaying, etc., a first calculation unit for calculating a noise dispersion degree of received data based on the output of the equalization unit, and a reception unit based on the output of the equalization unit. Second calculating means for calculating a phase error dispersion degree of data, first numerical converting means for converting the noise dispersion degree into a numerical value and displaying it on the display means, and the display means for converting the phase error dispersion degree into a numerical value. To display on the second
And digitizing means of.

According to a sixth aspect of the present invention, the data transmission / reception is performed through the accommodation line, and at the same time, the equalization means for removing the influence of noise or the like on the received data by the line, and the equalization means. In a communication device comprising a means for generating an eye pattern of received data based on an output and a display means for displaying a setting value peculiar to the device, an arbitrary one point in the eye pattern, and the one point. Means for selecting reference coordinate axes that are orthogonal to each other and a plurality of eye patterns that are symmetric at the intersection of the coordinate axes; and means that determines the rotation angles of the plurality of eye patterns based on the symmetry of the plurality of eye patterns And means for displaying a plurality of eye patterns rotated according to the rotation angle on the display means. In the above configuration, the quality of received data is accurately indicated on a low-resolution display device, and functions to facilitate observation of received quality.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. [Explanation of Eye Pattern] FIGS. 1 and 2 are diagrams showing examples of the eye pattern. Among them, FIG. 29, and an eye pattern of 9600 bps defined by H.29. 33 shows an eye pattern of 14400 bps defined by 33. The PSK signal and QAM signal are given by the following equations. _{S (t) = a 1 (} t) sin (w c t) + a 2 (t) cos (w c t) ... (1) where, S (t): modulated signal w _c at time t: the carrier ( Carrier) Angular frequency a ₁ (t): Amplitude of in-phase component at time t a ₂ (t): Amplitude of quadrature component at time t

[0011] The eye pattern, the amplitude a ₁ of the in-phase component of the equation (1) (t) to the horizontal axis, is plotted on the vertical axis the amplitude a ₂ (t) of the quadrature component. As can be seen from FIGS. 1 and 2, the number of points of the eye pattern is V. 29, and V.I.
33 are 16 points and 128 points respectively, and the number of points increases exponentially as the transmission speed increases. Also,
3 to 5 respectively show V.I. 29 shows an eye pattern in FIG. 29 when noise, phase jitter, and impulse noise occur on the transmission path.

[First Embodiment] FIG. 6 is a block diagram showing the outline of a communication apparatus according to the first embodiment of the present invention. In the figure, an operation panel, a data storage memory, a data input unit (scanner or the like), a data output unit (printer or the like) are not shown, and only main components are shown. In FIG. 6, 200 is a controller that controls the entire apparatus, 201 is a line interface that transmits and receives data to and from the line, and is an interface with the device,
Reference numeral 202 denotes a modem unit that controls data exchange between the line interface 201 and the controller 200, and performs modulation and demodulation to interface the line data with data in the communication device. Reference numeral 303 denotes a display device that displays a setting state of the device.

Hereinafter, the processing of the present apparatus when receiving data will be mainly described. The data from the line is passed to the modem unit 202 through the line interface 201,
It is demodulated here to obtain a baseband signal of an in-phase component / quadrature component. This baseband signal is passed to the controller 200 as received data through equalization, determination, differential decoding, descrambler, etc., but in FIG.
In 02, only the equalization and determination unit is shown. Here, the equalizer 100 removes the signal distortion component due to the line from the baseband signal, and the equalizer residual error is removed by the determiner 101, so that the baseband signal is determined as a point on the regular recommendation.

The eye pattern is equalized by the equalizer 1 as described above.
00 is the in-phase and quadrature components of the output signal plotted on the x-axis and the y-axis, respectively.
Using the axis display input, the following processing is applied to these input signals to simplify the data. Two
The signal output to one axis (for example, the x-axis) of the dimensional axis is equalizer output (here, the in-phase and quadrature components thereof are Zi,
Zq) and the output of the discriminator (similarly, in-phase and quadrature components are Ai and Aq), which is the square value of the difference. In order to obtain this value, subtracters 105 and 106 use Zi-Ai and Zq. −
Aq is also (Zi-Ai) in the multipliers 107 and 108.
² and (Zq-Aq) ² are calculated. And adder 1
At 09, E ² = (Zi-Ai) ² + (Zq-Aq) ² (2) is obtained.

Next, the signal output to the other axis (for example, the y axis) is a phase error (θ _e ) which mainly represents the influence of phase jitter, which is calculated by the phase error calculator 110. It In this embodiment, in order to further simplify the display, the absolute value is calculated by the absolute value unit 111 and output. Here, the phase error θ _e indicates the phase difference from the judgment value phase of the pattern that is circularly distributed symmetrically with respect to the origin as shown in FIG. 4 in the eye pattern coordinates.
Usually, the phase error is calculated using the following formula.
Note that the following equations are generally used in the phase error estimator of the phase controller inside the modem, and the explanation of the proof of the equations is omitted.

Θ _e = (Zq · Ai−Zi · Aq) / Ai ² + Aq ² (3) Here, Zi and Zq are in-phase components and quadrature components of the equalizer output, and Ai and Aq are , Represents the in-phase component and the quadrature component of the output of the discriminator. The squared error E ² and the absolute value phase error | θ _e | calculated in this way are quantized by the quantizers 113 and 112, respectively, in order to process them into a range that can be displayed on the low resolution display device of the present communication device. Further, the data is input to the x-axis display input and the y-axis display input of the controller 200 via the bar graph data generators 114 and 115 that generate bar graph data from the origin to the input value within one display period. It should be noted that, here, positive number conversion is performed as the simplest method of quantization.

FIG. 7 shows an example in which the reception quality pattern is displayed on the display device 203 using the above processing. In the figure, the figure at the right end is the reception quality pattern 204, which forms a two-dimensional bar graph. Further, in the figure, the horizontal direction indicates the x-axis and the vertical direction indicates the y-axis. Further, FIG. 8 is an enlarged view of the above reception quality pattern, in which the horizontal axis shows the squared error and the vertical axis shows the absolute value phase error. In comparison with the eye pattern shown in FIG. Makes it easier to understand the contents. That is, in FIG.
In (b), the variance of the noise (x-axis direction) and the variance due to the phase error (y-axis direction) are approximately the same, which is the variance due to the noise corresponding to the state of FIG. 3 above, and ( b) is
It is shown that the degree of dispersion is higher than that in (a).

Further, FIG. 8C shows that the degree of dispersion due to the phase error is larger than the dispersion due to noise, which corresponds to the above-mentioned state of FIG. 4, and the dispersion due to the phase jitter is large. .. As described above, according to the present embodiment, the eye pattern is converted into a simplified pattern and displayed as a reception quality pattern indicating the reception state of data from the line on the low resolution display device of the communication device. By doing so, the reception quality pattern can be displayed in a narrow area called the display of the communication device or in an empty area on the display,
Further, since it can be displayed together with a normal message in the communication device, the service person can easily, accurately, and promptly receive the reception quality without damaging the function of the communication device itself during maintenance of the communication device. The effect is that it can be monitored.

Further, by adopting a simpler reception quality pattern, it is possible to use a low-resolution, low-resolution display for displaying alphanumeric characters and katakana as a display, and the reception quality can be obtained without increasing the cost of the apparatus. There is an effect that the monitor of can be realized. Although the horizontal axis represents the noise component and the vertical axis represents the phase error component in the above embodiment, the display axis direction is not limited to this, and they may be reversed, for example. It goes without saying that the same effect can be obtained in this case as well. Further, in the above-described embodiment, the positive quantization is performed as the quantization, but in general, a quantization method having a plurality of quantization levels other than the positive quantization may be used. In this case, for example, by optimizing the quantization level according to the resolution of the display device, a higher quality reception quality pattern can be displayed.

<Modification> In the first embodiment described above, the reception quality can be monitored by displaying a simplified pattern of the eye pattern. However, in this modification, the reception quality is indicated by a numerical value. explain. FIG. 9 is a block diagram showing an outline of a communication device according to this modification. In the figure, as in the above embodiment, the operation panel, the data storage memory, the data input unit (scanner or the like), the data output unit (printer or the like) are not shown, and only the main components are shown. The same components as those of the communication device according to the first embodiment are designated by the same reference numerals, and their description will be omitted.

In the apparatus according to the present modification, the eye pattern is not displayed as it is, but the numerical data by which the cause of dispersion of the eye pattern can be observed is displayed on the display unit 303 by the following method. Here, there are two types of numerical values displayed on the display device 303, one is a mean square error, and the other is a mean absolute phase error. The squared error means the subtractors 105 and 106, the multipliers 107 and 108, and the adder 1 as in the above embodiment.
At 09, the value is calculated by the above equation (2) using the equalizer output (Zi, Zq) and the determiner output (Ai, Aq).

The absolute phase error is the absolute value of the jitter and carrier phase error θ _e shown in FIG. 4, and is calculated by the following formula. That is, | θ _e | = | (Zq · Ai−Zi · Aq) / Ai ² + Aq ² | ... (4). In the communication device according to the present modification, these E ² , |
θ _e | is a value calculated for each symbol interval. 29, V.I. In the case of 33, the symbol interval is 1 / 2400≈415 μsec, and even if this is displayed on the display device 303 as it is, the displayed numerical value cannot be visually recognized by human eyes.

Therefore, in this modification, a method of averaging E ² , | θ _e | at intervals of a plurality of symbols, for example, data to be passed to the controller 200 is

[0024]

[Equation 5]

The values are averaged by performing the calculation in. Note that this averaging is performed by the averaging devices 150 and 151 shown in FIG.
These averagers clear the internal data when the number of averaged data n exceeds a predetermined number, and
It is configured to calculate an average value from the next n pieces of data. Therefore, the outputs of the averagers 150 and 151 are the average of n data before that, and the output repetition time is n.
× symbol interval (for example, 1 when n = 2400)
(Second interval), the display on the display 303 can be recognized by human eyes. Further, FIG. 10 shows an example in which the reception quality value in this modification is displayed on the display device 303.

As described above, in the present modification, the dispersion of the eye pattern is displayed by a numerical value for each dispersion cause, so that the dispersion cause can be accurately recognized by the numerical value, and the display is also a normal display. Low resolution and low cost can be used. The number of times of averaging is 240 as described above.
The value is not limited to 0, and any value may be used as long as a human can visually recognize the display on the display. The number of times of averaging may be set according to the purpose of observation. For example, the number of averaging is set to be large when observing the secular change of the line state, and the number of averaging is set to be small when observing a sudden spread of dispersion.

[Second Embodiment] Next, a second embodiment according to the present invention will be described. FIG. 11 is a block diagram showing an outline of a communication device according to the second embodiment of the present invention. In the figure, as in the first embodiment, the operation panel, the data storage memory, the data input unit (scanner or the like), the data output unit (printer or the like) are not shown, and only the main components are shown. The same components as those of the communication device according to the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

Also in the communication apparatus according to this embodiment, the in-phase component (Zi) and the quadrature component (Zi) of the output signal of the equalizer 100 are used.
q) is plotted on the x-axis and the y-axis, and the signals corresponding to Zi and Zq are latched by the latches 208 and 209 and passed to the controller 200. Therefore, a method of limiting the eye pattern in the device according to the present embodiment will be described.

The judgment values (Ai, Aq) obtained by judging the eye pattern by the judgment device 101 are converted into absolute values by the absolute value detectors 203 and 204, respectively, and the respective absolute values are determined as in-phase components Di, Dq (Di ≧). 0, Dq ≧ 0) and the comparator 20
5,206 will be compared. Then, as a result, if the two values match, the outputs from the comparators 205 and 206 are input to the AND circuit 207. That is, the comparator 20
AND circuit 20 only when there is an output from 5,206
7 enables the latch enable signals for the latches 208 and 209. In other words, the signal representing the eye pattern is latched only when the absolute value of the determination value is equal to the predetermined point (Di, Dq).

Specifically, the above comparison is based on | Ai | = D
i, | Aq | = Dq is determined, and the eye pattern displayed at this time is (Di, Dq), (Di, -Dq), (when the determination value is (Di, Dq). -D
i, -Dq), (-Di, Dq), that is, (D
Only points symmetrical to the x-axis, the origin, and the y-axis with respect to (i, Dq) are extracted and latched.

Next, the rotation control in this embodiment will be described. The determination values Ai and Aq corresponding to the outputs Zi and Zq of the equalizer 100 are input to the code determination units 215 and 216, respectively, and only that code is determined and the determination result code is the rotation angle generator. 211 is input. The rotation angle generator 211 generates four signals R _{0 to} R ₃ corresponding to the rotation angles for rotating the equalizer outputs Zi and Zq according to the two input codes.

FIG. 12 is a diagram showing an input / output relationship in the rotation angle generator 211. As shown in the figure, for example,
When the inputs are + and −, that is, Ai is positive and Aq is negative, the rotation angle generator 211 generates R ₀ = 0, R ₁ = −1, R ₂ = 0,
It outputs four signals of R ₃ = 1. Here, the rotation angle generator 2
11 is a rotation of 0 ° when the input is +, +, a rotation of 90 ° when the input is +, −, a rotation of 180 ° when the input is −, −, and
A rotation of 270 ° is represented when − and +. The rotation directions are all counterclockwise.

Then, the equalizer outputs Zi and Zq are rotated by the above-mentioned angle in the rotator 210 by the above signals R _{0 to} R ₃ . The rotator 210 actually calculates its output signal by the following formula. That is, Yi = ZiR ₀ + ZqR ₁ (6) Yq = ZiR ₂ + ZqR ₃ (7) Here, Yi and Yq are output signals of the rotator corresponding to the respective Zi and Zq. Therefore, when the above equations (6) and (7) are expressed by a matrix,

[0034]

[Equation 8]

It becomes After all, (Yi, Yq) becomes (Z
i, Zq) are rotated by 0 °, 90 °, 180 °, and 270 °, respectively. Yi and Yq are latched in the latches 208 and 209 only for the four determination values determined when the determination value in the comparator is (Di, Dq) as described above, and the signals after latching are , And is passed to the controller 200 and displayed on the display 303. FIG. 13 is a display example of the device according to the present embodiment, in which the receiving status and the telephone number of the other party are displayed, and the reception pattern 305 is
The eye pattern of 4 points is rotated to 1 point and it becomes a set.

As described above, according to this embodiment,
By extracting 4 points from all eye patterns and then concentrating and displaying 4 points, it is possible to accurately and surely display the eye pattern on a display with low resolution and low cost. The effect is that the cause of dispersion and line quality can be accurately and quickly grasped and observed. The present invention may be applied to a system including a plurality of devices or an apparatus including a single device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0037]

As described above, according to the present invention,
By simplifying the display of the eye pattern indicating the reception quality, the reception quality can be easily, accurately, and quickly grasped even with a low-resolution display.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an eye pattern showing reception quality,

FIG. 2 is a diagram showing an example of an eye pattern indicating reception quality,

FIG. 29 is a diagram showing an eye pattern in the case where noise occurs on the transmission line in FIG.

FIG. 29 is a diagram showing an eye pattern in the case where phase jitter occurs on the transmission line in FIG.

FIG. 5: 29 is a diagram showing an eye pattern in the case where impulse noise occurs on the transmission line in FIG.

FIG. 6 is a block diagram schematically showing a communication device according to the first embodiment of the present invention,

FIG. 7 is a diagram showing an example in which a reception quality pattern according to the first embodiment is displayed on a display device;

FIG. 8 is an enlarged view of a reception quality pattern according to the first embodiment,

FIG. 9 is a block diagram showing an outline of a communication device according to a modification of the first embodiment,

FIG. 10 is a diagram showing an example in which a reception quality value in a modified example is displayed on a display device;

FIG. 11 is a block diagram showing an outline of a communication device according to a second embodiment of the present invention,

FIG. 12 is a diagram showing an input / output relationship in a rotation angle generator according to a second embodiment,

FIG. 13 is a diagram showing a display example on the communication device according to the second embodiment;

FIG. 14 is a diagram showing a configuration example of conventional eye pattern observation.

[Explanation of symbols]

 202 modem unit 100 equalizer 101 determiner 105, 106 subtractor 107, 108 multiplier 109 adder 110 phase error calculator 111 absolute value unit 112, 113 quantizer 150, 151 averager 303 indicator

Claims (6)

[Claims] 1. An equalizing means for transmitting and receiving data through an accommodating line and removing an influence of noise or the like on received data by the line, and a display means for displaying a set value or the like peculiar to the apparatus. In the communication device, first computing means for calculating the noise dispersion degree of the received data based on the output of the equalization means, and phase error dispersion degree of the received data based on the output of the equalization means. A second calculating means; and means for displaying the noise dispersion degree and the phase error dispersion degree on the display means so that the noise dispersion degree and the phase error dispersion degree are orthogonal to each other. Communication device. 2. The first computing means comprises first quantizing means for quantizing the noise variance to match the resolution of the display means, and the second computing means comprises phase error variance. The communication apparatus according to claim 1, further comprising a second quantizing unit that quantizes the degree to match the resolution of the display unit. 3. The communication device according to claim 1, wherein the noise variance is a squared error, and the phase error variance is an absolute value phase error. 4. An equalizing means for transmitting and receiving data via the accommodated line and removing an influence of noise or the like on the received data by the line, and a display means for displaying a set value or the like peculiar to the apparatus. In the communication device, first computing means for calculating the noise dispersion degree of the received data based on the output of the equalization means, and phase error dispersion degree of the received data based on the output of the equalization means. Second computing means; first digitizing means for digitizing the noise dispersion degree and displaying it on the display means; and second digitizing means for digitizing the phase error dispersion degree and displaying it on the display means. And a communication device. 5. The noise variance is a squared error, the phase error variance is an absolute phase error, and the first digitizing means calculates a plurality of data of the squared error as time. 5. The communication apparatus according to claim 4, wherein the averaging is performed, and the second digitizing means time averages a plurality of pieces of the absolute value phase error data. 6. An equalizing means for transmitting and receiving data through the accommodating line and removing the influence of noise or the like on the received data by the line, and an eye for the received data based on the output from the equalizing means. In a communication device including a unit for generating a pattern and a display unit for displaying a setting value specific to the device, an arbitrary point in the eye pattern, a reference coordinate axis orthogonal to the point, and the coordinate axis. Means for selecting a plurality of eye patterns that are symmetric at the intersection point, a means for determining the rotation angles of the plurality of eye patterns based on the symmetry of the plurality of eye patterns, and a plurality of means that rotate according to the rotation angle. And a means for displaying the eye pattern on the display means.