JP2001196977A - Waveform equalizing controller, and waveform equalizing control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost waveform equalizing controller with high performance by making stability at low C/N compatible with tracking performance and a converging speed at an initial operation when distortion in a waveform equalizer fluctuates. SOLUTION: The waveform equalizing controller provided with a waveform equalizer 101 that reduces the transmission line distortion of an input signal on the basis of the LMS algorithm to control tap coefficient update, is provided with an error estimate section 102 that estimates an error signal 102S from an output signal 101S of the waveform equalizer 101 and provides an output, a step size decision section 104 that generates a step size 104S of an optional magnitude and provides an output, and a coefficient update amount calculation section 103 that calculates a tap coefficient update amount 106S on the basis of the error signal 102S, the step size 104S and data 105S used for tap coefficient update.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform equalization control device and a waveform equalization control method, and more particularly, to update control of tap coefficients of a waveform equalizer for reducing transmission path distortion of a digital signal used for digital broadcasting. About what to do.

[0003]

[Prior art]

[0004] Digital broadcasting was initially performed mainly by satellite broadcasting, but in recent years, terrestrial broadcasting has also been increasingly digitized. In this digital terrestrial broadcasting, a waveform equalization technique for reducing transmission path distortion is essential. In the following, a conventional waveform equalization control device for digital terrestrial broadcasting will be described using an 8-level VSB adopted in the United States.
(Digital Tel Band) using a (Vestigial Side Band: residual sideband) modulation method.
An example is described.

FIG. 19 is a block diagram showing a configuration of a DTV type waveform equalization control device. In FIG. 19, a conventional waveform equalization control device receives an input signal 100S as an input,
A waveform equalizer 101 that outputs an output signal 101S that has been subjected to waveform equalization processing, and an error estimator 1901 that estimates an error of the output signal 101S and outputs the error as an error signal 1901S.
And a step size 104S, data 105S used for coefficient update, and an error signal 1901S, a coefficient update amount calculation unit 103 for calculating a tap coefficient update amount 106S.
And The error estimating unit 1901 further includes an output error estimating unit 1502 that receives the output signal 101S as an input and outputs an output error signal 1501S, and a coefficient updating error generating unit 1902.

FIG. 20 is a diagram showing a configuration of a signal format of the DTV system. As shown in FIG. 20, the DTV signal format includes an area including a data signal 3101 such as video and audio, an area including a field synchronization signal 3102, and an area including a segment synchronization signal 3103.

FIG. 21 shows the structure of the field synchronization signal. As shown in FIG.
102 is a PN511 signal 3201 and three PN63
A signal 3202 and a control signal 3203 are included.
Note that the field synchronization signal # 2 and the field synchronization signal #
The difference from 1 is only that the second value of the PN63 signal 3202 is reversed. Also, in FIG. 21, the numerical values (+7, +5, +3, +
1, -1, -3, -5, -7) show eight numerical values of the eight-level VSB modulation method. This DTV signal has 832 symbols and 313 segments per frame. The PN511 signal 3201 is the PN51 signal.
1 = X ＾ 9 + X ＾ 7 + X ＾ 6 + X ＾ 4 + X ＾ 3
+ X + 1 (generator polynomial: “＾” in the equation represents a power), and is represented by Pre-load 010000000 (a binary representation of an initial value). PN63 signal 3202
Is PN63 = X ＾ 6 + X + 1 and Pre-load
100111. The PN511 signal 3201 has 511 symbols, and the PN63 signal 3202 has 63 symbols.
The symbol and control signal 3203 are 128 symbols, and the total of the field synchronization signal 3102 is 828 symbols.

Next, the operation of the conventional waveform equalization control device will be described with reference to the drawings. As shown in FIG. 19, the waveform equalization control device of the DTV system uses the octal VSB-modulated DT
The V signal is waveform-equalized by the waveform equalizer 101 to reduce distortion and generate an output signal 101S, and the output error estimating unit 15
02, the error between the output signal 101S and the most probable symbol value of the eight symbol values is determined by the output error signal 150.
Generated as 1S. FIG. 22 shows the relationship between the output error signal and the error signal. The output error signal 15 shown in FIG.
01S is a coefficient update error generation unit 1902, and Blind Eq.
ualization and Carrier Recovery Using a “Stop-and-
Go ”, Decision-Directed Algorithm IEEE TRANSACTION
S ON COMMUNICATIONS, VOL.COM35, NO.9, SEPTEMBER 198
22 according to the value of the output signal 101S based on the Stop & Go algorithm described in pp.877-887 of FIG.
The signal is converted into an error signal 1901S as shown in FIG.
The coefficient update amount calculation unit 103 uses the error signal 1901S, the step size 104S, and the coefficient update data 105S to perform LMS (Least Mean Square).
e: Least square error), and generates the tap coefficient update amount 106S based on the algorithm.

The LMS algorithm is an algorithm for updating the tap coefficient Ci of the tap i in the transversal filter of the waveform equalizer 101 for the nth time based on the following (Equation 1). Ci (n + 1) = Ci (n) −α × e (n) × di (n) (Equation 1)

Here, α is the step size 104S,
e (n) indicates error signal 1901S, di (n) indicates coefficient updating data 105S, and -α × e (n) × di.
(N) shows the tap coefficient update amount 106S. The coefficient update data 105S is the tap i at the time of the n-th update.
Is the data in.

There are two methods for generating the output error signal 1501S by the output error estimator 1502. One is DTV
In this method, a PN511 signal 3201 and a PN63 signal 3202 included in a field synchronization signal 3102 of a signal are fetched, compared with ideal values of the PN511 signal 3201 and the PN63 signal 3202, and an error thereof is used as an output error signal 1501S.

On the other hand, the other is an 8-value V which is the closest to the data signal 3101 inserted in the data period of the DTV signal.
This is a method in which a fixed value of the SB modulation is compared, and the error is used as an output error signal 1501S.

Since the DTV signal uses an 8-level VSB modulation method, as shown in FIG. 21, eight values (+
7, +5, +3, +1, -1, -3, -5, -7). Generally, when an 8-level VSB modulated DTV signal is received, quantization of about 10 bits is performed. For example, 10
The DTV signal quantized to bits has a value (0 to 102) that can be represented by 10 bits when there is no distortion at all.
Only eight fixed values can be obtained for 3). The output error estimating unit 1502 applies a PN511 signal 3201 to the input field synchronization signal 3102 of the DTV signal.
And the error of the PN63 signal 3202 from the ideal value is calculated, and for the data signal 3101, the error with the closest value from the eight fixed values is calculated, and this error is used as the output error signal 1501S. .

[0014]

[Problems to be solved by the invention]

The conventional waveform equalization control device is configured as described above, and by using the waveform equalization control device, the waveform equalizer can be controlled to obtain a DTV signal with reduced distortion. . That is, by estimating the transmission line distortion of the input signal and performing learning control so that the tap coefficient of the transversal filter included in the waveform equalizer is updated at every step size so as to cancel the distortion. A signal with reduced transmission path distortion can be obtained as an output signal of the waveform equalizer. However, the conventional waveform equalization control device has the following problems.

The first problem is that the step size, which is the increment of the tap coefficient, is fixed. In general, when the step size is increased, the follow-up performance when the distortion fluctuates and the convergence speed at the time of the initial operation are improved, but on the other hand, it is susceptible to noise and the stability at low C / N is reduced. Conversely, when the step size is reduced, the influence of noise is reduced, and the stability at the time of low C / N is improved.
The convergence speed of the waveform equalization operation at the time of the initial operation is reduced.

The second problem is that the coefficient update amount calculation unit needs two multipliers to calculate the coefficient update amount of one tap, and the circuit scale is large.

The third problem is that when the Stop & Go algorithm determines Stop, the output of the coefficient update amount calculator becomes “0” until the next iteration (update of tap coefficients), and the coefficient update amount calculator is valid. It is not used, and the followability when the distortion fluctuates and the convergence speed in the initial operation are reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and achieves both the follow-up performance when signal distortion fluctuates, the convergence speed at the time of initial operation, and the stability at low C / N.
It is an object of the present invention to provide a high-performance and low-cost waveform equalization control device and a waveform equalization control method.

[0020]

[Means for Solving the Problems]

To achieve the above object, a waveform equalization control device according to a first aspect of the present invention includes a waveform equalizer that reduces transmission line distortion of an input signal based on an LMS algorithm. A waveform equalization control device for controlling updating of a tap coefficient of a filter included in a filter, comprising: an error estimating unit that estimates an error of the output signal from an output signal of the waveform equalizer and outputs the error as an error signal; The step size upper limit value and the step size lower limit value which are the upper limit value and the lower limit value of the step size which are the increments of the signal and the tap coefficient are input, and the step size upper limit value and the step size lower limit value or less are input. A step size determining unit that adaptively generates and outputs a step size having a size corresponding to the error signal; the error signal; the step size; And a coefficient updating quantity calculation unit for calculating a tap coefficient updating amount based on the data used for the new,
It is characterized by the following.

According to a second aspect of the present invention, in the waveform equalization control device according to the first aspect, the step size determining unit squares the error signal to the square. A multiplier for generating an error, a square error storage unit for storing a square error generated at the time of updating the previous tap coefficient,
A subtractor for generating a difference of a square error, which is a difference between a square error output from the multiplier and a square error generated at the time of updating the previous tap coefficient stored in the square error storage unit; A first comparator for comparing the error with a first threshold value;
A second comparator for comparing the squared error with a second threshold, a third comparator for comparing an absolute value of the difference between the squared error and a third threshold, and a third comparator used at the time of updating the previous tap coefficient. A step size storage unit for storing the obtained step size, a step size stored in the step size storage unit, an output of the first comparator, an output of the second comparator, An output of a comparator, the step size upper limit value, and the step size lower limit value are input, and a step size increasing / decreasing unit that generates a step size to be used for updating the current tap coefficient is provided. Is what you do.

According to a third aspect of the present invention, in the waveform equalization control device according to the second aspect, the second threshold value is such that the square error is larger than the value. For example, the first threshold value is a value at which the waveform equalization operation of the waveform equalizer tends to diverge, and the first threshold value is the waveform equalization operation of the waveform equalizer if the square error is smaller than the value. Is a value that indicates either a convergence state or a convergence completion state. The third threshold value is a value of the difference between the square errors when the square error is smaller than the first threshold value. If the absolute value is larger than the third threshold, the waveform equalizer is in a state in which the waveform equalization operation is converging. If the absolute value is equal to or smaller than the third threshold, the waveform equalizer performs the operation. A value at which the waveform equalization operation is in a state of completion of convergence; From the comparison result of the comparator of No. 3,
If the square error is larger than the second threshold, the step size is reduced by a fixed amount, the square error is smaller than the first threshold, and the absolute value of the difference between the square errors is equal to or smaller than the third threshold. If so, reduce the step size by a fixed amount and
If the squared error is smaller than the first threshold and the absolute value of the difference between the squared errors is larger than the third threshold, the step size is increased by a fixed amount, otherwise the step size is not changed. It is characterized by the following.

According to a fourth aspect of the present invention, in the waveform equalization control device according to the second aspect, the second threshold is such that the square error is larger than the value. For example, the first threshold value is a value at which the waveform equalizing operation of the waveform equalizer tends to diverge, and the first threshold value is the waveform equalizing operation of the waveform equalizer if the square error is smaller than the value. Is a value that indicates either a convergence state or a convergence completion state. The third threshold value is a value of the difference between the square errors when the square error is smaller than the first threshold value. If the absolute value is larger than the third threshold, the waveform equalizer is in a state in which the waveform equalization operation is converging. If the absolute value is equal to or smaller than the third threshold, the waveform equalizer performs the operation. The step size increasing / decreasing unit is a value at which the waveform equalization operation is in a state where convergence is completed. If the square error is larger than the second threshold, the step size is reduced by a fixed ratio, the square error is smaller than the first threshold, and the absolute value of the difference between the square errors If the value is equal to or smaller than the third threshold, the step size is reduced by a fixed ratio, the square error is smaller than the first threshold, and the absolute value of the difference between the square errors is smaller than the third threshold. When the size is large, the step size is increased by a fixed ratio, otherwise, the step size is not changed.

According to a fifth aspect of the present invention, there is provided a waveform equalization control device including a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm. A waveform equalization control device that controls updating of a tap coefficient, comprising: an error estimating unit that estimates an error of the output signal from an output signal of the waveform equalizer and outputs the error as an error signal; A signal determination unit that determines the magnitude of the determination error probability and outputs a determination signal, and receives the determination signal as an input, and outputs a value of a magnitude corresponding to the determination signal as a step size that is a step of updating the tap coefficient. And a coefficient update amount calculation unit that calculates a tap coefficient update amount based on the error signal, the step size, and data used for tap coefficient update. It is characterized in.

According to a sixth aspect of the present invention, there is provided the waveform equalization control device according to the fifth aspect, wherein the signal determination section indicates that the output signal is known. And three kinds of judgment signals, that is, a case where the probability of the judgment error of the output signal is small and a case where the probability of the judgment error of the output signal is large is output. It is.

According to a seventh aspect of the present invention, in the waveform equalization control device according to the sixth aspect of the present invention, the step size determining section determines that the determination signal is a signal whose output signal is known. When it indicates that there is, the first step size setting value is output as the step size, and when it indicates that the probability of the determination error of the output signal is small, a value smaller than the first step size setting value is used. If a certain second step size setting value is output to indicate that the probability of a decision error in the output signal is high, the second
And outputting a third step size set value which is smaller than the step size set value.

A waveform equalization control device according to a eighth aspect of the present invention includes a waveform equalizer that reduces transmission line distortion of an input signal based on an LMS algorithm. A waveform equalization control device that controls updating of a tap coefficient, comprising: an error estimating unit that estimates an error of the output signal from an output signal of the waveform equalizer and outputs the error signal as an error signal; And a step size setting unit that determines a step size that is a step of updating the tap coefficient, based on the error signal, the step size, and data used for tap coefficient update. A coefficient update amount calculation unit for calculating a tap coefficient update amount.

According to a ninth aspect of the present invention, in the waveform equalization control apparatus according to the eighth aspect, the plurality of step size setting values are different from the first step size setting value. A second step size setting value that is larger than the first step size setting value, wherein the step size determining unit compares the absolute value of the error signal with the threshold value; And a selector for selecting one of the first step size setting value and the second step size setting value from the comparison result output from and outputting as the step size.
It is characterized by the following.

According to a tenth aspect of the present invention, there is provided the waveform equalization control unit according to the ninth aspect, wherein the threshold value is set when the absolute value of the error signal is equal to or less than the threshold value. The waveform equalizer is a value that is substantially converged, and the step size determination unit sets the first step size setting value as the step size when the absolute value of the error signal is equal to or less than the threshold. And outputting the second step size setting value as the step size when the absolute value of the error signal exceeds the threshold value.

A waveform equalization control device according to a twelfth aspect of the present invention includes a waveform equalizer that reduces transmission line distortion of an input signal based on an LMS algorithm. What is claimed is: 1. A waveform equalization control device for controlling updating of tap coefficients, comprising: an error estimating unit that estimates an error of an output signal from an output signal of the waveform equalizer and outputs the error signal as an error signal; An error quantization unit that converts and outputs a quantization error signal having a value of タ ッ プ, a tap size based on the quantization error signal, a step size that is a step of updating the tap coefficient, and data used for updating the tap coefficient. A coefficient update amount calculation unit for calculating a coefficient update amount.

According to a twelfth aspect of the present invention, in the waveform equalization control apparatus according to the eleventh aspect, the error quantizing unit converts the error signal into a power of two. The error signal is converted into a quantized error signal having the same sign as the error signal and having a maximum value equal to or smaller than the error signal and output.

According to a thirteenth aspect of the present invention, in the waveform equalization control device according to the eleventh aspect, the error quantizing unit converts the error signal into a power of two. The error signal is converted into a quantized error signal having the same sign as that of the error signal and having a minimum value equal to or larger than the error signal and output.

A waveform equalization control device according to a fourteenth aspect of the present invention includes a waveform equalizer that reduces transmission line distortion of an input signal based on an LMS algorithm. A waveform equalization control device that controls updating of a tap coefficient, comprising: an error estimating unit that estimates an error of the output signal from an output signal of the waveform equalizer and outputs the error as an error signal; A data quantization unit that converts and outputs quantized data having a value of a power of 2, a tap coefficient update based on the error signal, a step size that is a step size of updating the tap coefficient, and the quantized data. And a coefficient update amount calculation unit for calculating the amount.

In the waveform equalization control device according to a fifteenth aspect of the present invention, in the waveform equalization control device according to the fourteenth aspect, the data quantizing unit transmits the data used for updating the tap coefficient to two. Of the exponentiation of the tap coefficients, the data is converted into quantized data having the same sign as the data used for updating the tap coefficients and having an absolute value equal to or smaller than the data used for updating the tap coefficients, and output.

In the waveform equalization control device according to a sixteenth aspect of the present invention, in the waveform equalization control device according to the fourteenth aspect, the data quantizing unit sets the data used for updating the tap coefficient to two. Of the power of, the data is converted into quantized data having the same sign as the data used for updating the tap coefficients and having an absolute value equal to or smaller than the data used for updating the tap coefficients.

A waveform equalization control device according to a seventeenth aspect of the present invention includes a waveform equalizer that reduces transmission line distortion of an input signal based on an LMS algorithm. A waveform equalization control device that controls updating of tap coefficients, comprising: an error estimating unit that estimates an error of the output signal from an output signal of the waveform equalizer and outputs the error as an error signal; and a step of updating the tap coefficient. A step size quantization unit that converts the step size into a quantization step size having a value of a power of 2 and outputs the converted step size, based on the error signal, the quantization step size, and data used for tap coefficient update. A coefficient update amount calculation unit that calculates a tap coefficient update amount.

[0038] Also, in the waveform equalization control device according to claim 18 of the present invention, in the waveform equalization control device according to claim 17, the step size quantization unit sets the step size to a power of two. Among which, convert and output to a quantization step size having a maximum value equal to or less than the step size,
It is characterized by the following.

According to a nineteenth aspect of the present invention, in the waveform equalization control device according to the seventeenth aspect, the step size quantization unit sets the step size to a power of two. Among which, convert and output to a quantization step size having a minimum value equal to or greater than the step size,
It is characterized by the following.

A waveform equalization control device according to a twentieth aspect of the present invention includes a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and a filter included in the waveform equalizer. A waveform equalization control device that controls updating of tap coefficients, wherein an error of the output signal is estimated from an output signal of the waveform equalizer, and the estimated error corresponds to a predetermined range of the output signal. An error estimating unit that outputs an error signal with an error set to 0, a tap coefficient update amount is calculated based on the error signal, a step size that is a step size for updating the tap coefficient, and data used for updating the tap coefficient. A coefficient update amount calculator and the error signal, and an update timing signal for controlling a timing at which the coefficient update amount calculator calculates the tap coefficient update amount at a plurality of symbol intervals is output. And a number update timing controller, it is characterized in.

According to a twenty-first aspect of the present invention, in the waveform equalization control device according to the twentieth aspect, the coefficient update timing control unit includes: When to calculate the update amount,
When a predetermined symbol interval has elapsed since the previous timing,
In addition, the error signal is controlled at the first symbol time that is not 0.

A waveform equalization control device according to a twenty-second aspect of the present invention includes a waveform equalizer that reduces transmission line distortion of an input signal based on an LMS algorithm. A waveform equalization control device that controls updating of a tap coefficient, the output signal of the waveform equalizer being an input, an output error estimator that outputs an output error signal, and the output error signal and the output signal. As an input, an error estimating unit having a coefficient updating error generating unit that reduces a partial section of the output error signal at a fixed rate and outputs an error signal;
A coefficient update amount calculation unit that calculates a tap coefficient update amount based on the error signal, a step size that is a step of updating the tap coefficient, and data used for tap coefficient update. Things.

A waveform equalization control device according to a twenty-third aspect of the present invention includes a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm. A waveform equalization control device that controls updating of a tap coefficient, comprising, as an input, an output signal of the waveform equalizer, and an error rate measurement circuit that generates an error signal indicating a ratio of an error included in the output signal. An output error estimator that receives an output signal of the waveform equalizer as an input and outputs an output error signal, and a coefficient update error that receives the output error signal, the output signal and the error signal as inputs, and outputs an error signal. An error estimator having a generator, the error signal, a step size that is a step of updating the tap coefficient,
And a coefficient update amount calculation unit that calculates a tap coefficient update amount based on data used for tap coefficient update.

According to a twenty-fourth aspect of the present invention, in the waveform equalization control device according to the twenty-third aspect, the error generation unit for updating the coefficient generates the output signal based on the error signal. When detecting that the ratio of errors included is smaller than a predetermined ratio, the same value as the output error signal is output as the error signal.

A waveform equalizing control method according to a twenty-fifth aspect of the present invention is a waveform equalizing control method for controlling updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm. An equalization control method,
Estimating an error of the output signal from the output signal of the waveform equalizer, an error estimation step of generating an error signal, and based on the error signal, an upper limit value of a step size that is a step of updating the tap coefficient. A step size determining step of adaptively determining a step size in a range not more than a certain step size upper limit value and not less than a step size lower limit value which is a lower limit value of the step size; and the error signal, the step size, and a tap coefficient. A coefficient update amount calculating step of calculating a tap coefficient update amount based on data used for update.

In a waveform equalization control method according to a twenty-sixth aspect of the present invention, in the waveform equalization control method according to the twenty-fifth aspect, the step size determination step comprises squaring the error signal to the square. A multiplication step for generating an error, a subtraction step for generating a difference of a square error which is a difference between a square error generated at a previous tap coefficient update and a square error generated in the multiplication step, and the square error A first comparing step of comparing the square error with a first threshold, a second comparing step of comparing the square error with a second threshold, an absolute value of a difference between the square error and a third threshold. A step size used in updating the previous tap coefficient, a comparison result in the first comparison step, a comparison result in the second comparison step, and a third comparison step. In the comparison step When the step size limit,
A step size generation step of generating a step size to be used for updating the current tap coefficient based on the step size lower limit value.

According to a second aspect of the present invention, there is provided a waveform equalization control method for controlling updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm. An equalization control method,
Estimating the error of the output signal from the output signal of the waveform equalizer, generating an error signal, determining the magnitude of the determination error probability of error estimation for the output signal, generating a determination signal, Determining a step size that is a step of updating the tap coefficient based on the determination signal; and calculating a tap coefficient update amount based on the error signal, the step size, and data used for updating the tap coefficient. And a step of performing the following.

According to a second aspect of the present invention, there is provided a waveform equalizing control method for controlling updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission path distortion of an input signal based on an LMS algorithm. An equalization control method,
An error estimating step of estimating an error of the output signal from an output signal of the waveform equalizer and generating an error signal; and updating the tap coefficient based on the error signal, a threshold value, and a plurality of step size setting values. And a coefficient update amount calculating step of calculating a tap coefficient update amount based on the error signal, the step size, and data used for tap coefficient update. It is characterized by having.

According to a waveform equalization control method according to claim 29 of the present invention, in the waveform equalization control method according to claim 28, the plurality of step size setting values are different from the first step size setting value. A second step size setting value larger than the first step size setting value, wherein the step size determining step includes a comparing step of comparing the absolute value of the error signal with the threshold value; A selection step of selecting one of the first step size setting value and the second step size setting value as the step size based on the comparison result in It is.

A waveform equalizing control method according to claim 30 of the present invention provides a waveform equalizing control method for controlling the updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm. An equalization control method,
An error estimating step of estimating an error of the output signal from an output signal of the waveform equalizer and generating an error signal with an error corresponding to a predetermined range of the output signal being 0 among the estimated errors; A coefficient update timing control step of generating an update timing signal for controlling a timing for calculating a tap coefficient update amount at a plurality of symbol intervals based on the error signal; and the error signal and a step size which is a step of updating the tap coefficient. And a coefficient update amount calculating step of calculating a tap coefficient update amount at a timing controlled by the update timing signal based on tap coefficient update data.

In the waveform equalization control method according to a thirty-first aspect of the present invention, in the waveform equalization control method according to the thirty-third aspect, the coefficient update timing control step includes a step of calculating a timing for calculating a tap coefficient update amount. , An update timing signal is generated at the first symbol time when a predetermined symbol interval has elapsed from the previous timing and the error signal is not zero.

A waveform equalizing control method according to a thirty-second aspect of the present invention is a waveform equalizing control method for controlling updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm. An equalization control method,
Estimating an output error from an output signal of the waveform equalizer and generating an output error signal; and, based on the output error signal and the output signal, reducing a partial section of the output error signal at a fixed rate. Generating an error signal; calculating a tap coefficient update amount based on the error signal, a step size that is a step of updating the tap coefficient, and data used for updating the tap coefficient. It is characterized by the following.

According to a third aspect of the present invention, there is provided a waveform equalization control method for controlling updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm. An equalization control method,
An output error estimating step of estimating an output error from an output signal of the waveform equalizer and generating an output error signal; and an error signal generating an error signal indicating a ratio of an error included in the output signal of the waveform equalizer. A generation step, a coefficient update error generation step of generating an error signal used for tap coefficient update based on the output error signal, the output signal, and the error signal, and the error signal and the update of the tap coefficient. It is characterized by comprising a coefficient update amount calculating step of calculating a tap coefficient update amount based on a step size as a step and data used for tap coefficient update.

In the waveform equalization control method according to a thirty-fourth aspect of the present invention, in the waveform equalization control method according to the thirty-third aspect, in the coefficient update error generation step, the error signal is used to output the error signal to the output signal. When detecting that the ratio of the included errors is smaller than a predetermined ratio, the same value as the output error signal is generated as the error signal.

[0055]

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a waveform equalization control device and a waveform equalization control method according to an embodiment of the present invention will be described with reference to the drawings. (Embodiment 1) The configuration of a waveform equalization control device according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG.
FIG. 2 is a block diagram illustrating a configuration of a waveform equalization control device according to the first embodiment. In FIG. 1, the waveform equalization control device according to the first embodiment includes an output signal 1 in which the transmission line distortion of the input signal 100S is reduced based on the LMS algorithm.
01S to output a waveform equalizer 101 and an output signal 101
An error estimating unit 102 that estimates an error of S and outputs it as an error signal 102S, and a coefficient update amount calculation that calculates a tap coefficient update amount 106S based on the error signal 102S, a step size 104S, and data 105S used for coefficient update. A step size determination unit 104 that receives the error signal 102S, the step size upper limit value 107S, and the step size lower limit value 108S, generates and outputs a step size 104S.

FIG. 2 is a block diagram showing a configuration of the step size determining section 104 provided in the waveform equalization control device according to the first embodiment. In FIG. 2, a step size determining unit 104 includes a multiplier 201 for squaring the error signal 102S to generate a square error 201S, and a square error 201S
, And the difference between the square error 201S output from the multiplier 201 and the square error stored in the square error storage unit 202 is calculated, and the difference is calculated as the square error difference 2
02S and a square error 201
A first comparator 204 for comparing S with a first threshold, 2
A second comparator 205 that compares the squared error 201S with the second threshold, a third comparator 206 that compares the absolute value of the squared error difference 202S with the third threshold, and stores the step size. A step size storage unit 207 and a step size increasing / decreasing unit 208.

Next, the operation of the waveform equalization control device according to the first embodiment will be described with reference to the drawings. FIG. 23 is a flowchart showing the operation of the waveform equalization control device according to the first embodiment. First, a signal from the transmission line is input to the input signal 100S via a tuner (not shown) and a detector.
Is input to the waveform equalizer 101. Error estimator 10
2 is an output signal 101 output from the waveform equalizer 101
An error to be used for updating the tap coefficients is estimated based on S, and an error signal 102S is generated and output based on the estimated error (step S101). Note that the error estimating unit 102 is, like the output error estimating unit 1502 of the conventional example,
When the output signal 101S has only one value, the difference between the ideal value of the value and the output signal 101S is estimated as an error, and the error signal 102 corresponding to the magnitude of the error is estimated.
Generate and output S. On the other hand, when the output signal 101S is a multi-valued signal, of the multi-valued ideal values, the difference between the ideal value closest to the output signal 101S and the output signal 101S is estimated as an error. An error signal 102S corresponding to this is generated and output. However, the input signal 100S in the first embodiment is not limited to the DTV signal.

The step size determining section 104 receives the error signal 102S, a step size upper limit 107S which is a value for determining the upper limit of the step size, and a step size lower limit 108S which is a value for determining the lower limit of the step size. The step size 104 whose value is changed in accordance with the error signal 102S within a range not less than the step size lower limit value 108S and not more than the step size upper limit value 107S.
S is determined and output (step S102). The coefficient update amount calculation unit 103 receives the error signal 102S, the step size 104S, and the data 105S, multiplies them as indicated by the second term on the right side of (Equation 1), and updates the tap coefficient. The amount 106S is output (step S103). And the tap coefficient update amount 106S is
The waveform equalizer 101 is used for updating the tap coefficient represented by (Equation 1). Step S10
The processing of 1 to S103 and the update of the tap coefficient in the waveform equalizer 101 are repeated as long as the waveform equalization processing in the waveform equalizer 101 is performed.

Here, the data 10 used for updating the coefficient is
As 5S, data stored in a data FIFO (not shown) of the waveform equalizer 101 is used. In addition,
The waveform equalization control device may separately include a FIFO for storing coefficient update data 105S. As the upper limit 107S of the step size and the lower limit 108S of the step size, values stored in a register (not shown) of the waveform equalization control device in advance are used.

Next, the operation of the step size determining unit 104 will be described. FIG. 24 is a flowchart showing the operation of the step size determining unit 104 according to the first embodiment. The multiplier 201 squares the error signal 102S to obtain 2
A square error 201S is generated (step S201). The square error storage unit 202 stores the square error at the time of the previous coefficient update. The subtracter 203 calculates a difference between the square error 201S and the square error at the time of the previous coefficient update, and outputs the difference as a square error difference 202S (step S20).
2). The square error storage unit 202 stores the current square error 201S
Is stored. The first comparator 204 compares the square error 201S with the first threshold (Step S203). The second comparator 205 compares the square error 201S with the second threshold (Step S204). The third comparator 206 compares the absolute value of the square error difference 202S with a third threshold (step S205). The step size increasing / decreasing unit 208 includes the first
, The comparison result of the second comparator 205, the comparison result of the third comparator 206, and the step size and the step size at the time of the previous coefficient update stored in the step size storage unit 207. An upper limit value 107S and a step size lower limit value 108S are input.

Here, the second threshold value is a square error 201S.
Is larger than that value, it is a value that tends to diverge in a state where the waveform equalizing operation for reducing the transmission path distortion in the waveform equalizer 101 cannot be controlled. The first threshold is 2
If the multiplication error 201S is smaller than the value, the value is a value in which the waveform equalization operation in the waveform equalizer 101 is in a state of being converged or completed. The third threshold is
When the square error 201S is smaller than the first threshold, 2
If the absolute value of the squared error difference 202S is equal to or greater than the third threshold, the value is a value in which the waveform equalization operation in the waveform equalizer 101 is converging. This is a value at which the waveform equalization operation in the converter 101 is in a state of convergence completion.

In practice, these first to third thresholds are set to approximate values by simulation, and
Ultimately, each is set at the discretion of the designer by examining the results of actual operation. That is, the second threshold is 2
If the multiplication error 201S is larger than the value, the value is set to a value determined by the designer that the waveform equalizing operation in the waveform equalizer 101 tends to diverge. When the square error 201S is smaller than the first threshold, the designer determines that the waveform equalization operation in the waveform equalizer 101 is either converging or convergence is completed. Is set to The third threshold is a square error 201S.
Is smaller than the first threshold, the difference of the squared error 20
If the absolute value of 2S is equal to or larger than the third threshold, the waveform equalizer 1
01 is determined by the designer to be converging, and if equal to or less than the third threshold, the waveform equalizer 1
When the waveform equalization operation in 01 is completed, the value is set to a value determined by the designer.

Next, the operation of the step size increasing / decreasing unit 208 will be described with reference to the drawings. FIG. 3 shows the first embodiment.
Size increasing / decreasing unit 208 of the waveform equalization control device according to
FIG. 5 is an explanatory diagram for explaining the operation of FIG. First, in FIG. 3, when the square error 201S is in the range of the area 1, that is, when the second comparator 205 determines that the square error 201S is larger than the second threshold, the waveform and the like are obtained. Since the converter 101 is determined to have a tendency to diverge, the step size increasing / decreasing unit 208 stores
A new step size obtained by reducing the previous step size stored in the step size by a certain amount is obtained.

When the square error 201S is in the range of the area 2, that is, the square error 201S is equal to or more than the first threshold and equal to or less than the second threshold by the first comparator 204 and the second comparator 205. Is determined, the waveform equalizer 101 is determined to be operating stably.
Let the same step size as the previous step size stored in 07 be the new step size.

When the square error 201S and the difference 202S between the square errors are in the range of the region 3 or the region 5, that is, the square error 201S is smaller than the first threshold value by the first comparator 204. When the third comparator 206 determines that the absolute value of the square error difference 202S is equal to or greater than the third threshold, the waveform equalizer 10
Since step 1 is determined to be converging, the step size increasing / decreasing section 208 obtains a new step size which is increased by a fixed amount from the previous step size stored in the step size storage section 207 in order to further increase the convergence speed. .
Here, the reason why the step size is increased in the range of the region 5 is to appropriately cope with a dynamic ghost, that is, a ghost that changes with time.

When the square error 201S and the difference 202S between the square errors are within the range of the region 4, that is, the first comparator 204 and the third comparator 206
When 01S is smaller than the first threshold and the absolute value of the square error difference 202S is equal to or smaller than the third threshold, the waveform equalizer 101 determines that the convergence has been almost completed. Therefore, in order to ensure stability at low C / N,
The step size increasing / decreasing unit 208 obtains a new step size reduced by a certain amount from the previous step size stored in the step size storage unit 207.

Further, the step size increasing / decreasing unit 208
New step size is step size upper limit 107S
In the above case, the step size upper limit value 107S is output as the step size 104S. When the new step size is equal to or smaller than the step size lower limit value 108S, the step size lower limit value 108S is set to the step size 104S.
Otherwise, the new step size is output as the step size 104S (step S
206).

As described above, according to the waveform equalization control device and the waveform equalization control method according to the first embodiment, the square error 201S and the difference 202S between the square errors are used to control the waveform equalizer 101. By providing the step size determination unit 104 that determines the state and increases or decreases the appropriate step size 104S accordingly, the convergence speed is high and the C / C is low.
There is an effect that a waveform equalization control device having high stability at the time of N can be realized.

In the first embodiment, the square error is used as an index for increasing or decreasing the step size. However, the index for increasing or decreasing the step size is not limited to the square error. (N is 1 or an integer of 3 or more) can achieve the same function. Here, when n is an odd number, it is assumed that the absolute value of the n-th power of the error is used as the n-th power error in the first and second comparators 204 and 205 and the like.

In the first embodiment, when the step size increasing / decreasing unit 208 increases / decreases the step size,
The step size is adjusted by adding or subtracting a predetermined amount to or from the previous step size. However, the step size is not limited to this. When the step size is increased, the previous step size is larger than 1 by one. Predetermined value,
For example, when multiplying by 1.1 or decreasing the step size, the previous step size is multiplied by a predetermined value smaller than 1, for example, 0.9. It may be performed by increasing or decreasing the number.

(Embodiment 2) The configuration of a waveform equalization control apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 4 is a block diagram showing a configuration of the waveform equalization control device according to the second embodiment. In FIG. 4, the waveform equalization control device according to the second embodiment includes a waveform equalizer 101 that outputs an output signal 101S in which the transmission line distortion of the input signal 100S is reduced based on the LMS algorithm, An error estimating unit 102 for estimating an error and outputting it as an error signal 102S; an error signal 102S, a step size 104S, and data 10
5S, a coefficient update amount calculation unit 103 that calculates a tap coefficient update amount 106S, a signal determination unit 401 that outputs a determination signal 401S, and a step size determination unit 4 that outputs a step size 104S corresponding to the determination signal 401S.
02.

Next, the operation of the waveform equalization control device according to the second embodiment will be described with reference to the drawings. FIG. 25 is a flowchart showing the operation of the waveform equalization control device according to the second embodiment. The error estimator 102 outputs the output signal 10
Estimate the error from 1S to use for tap coefficient update,
Generating an error signal 102S based on the estimated error;
Output (Step S301). The signal determination unit 401
From the synchronization signal included in the input signal 100S, the output signal 1
The type of the signal content of 01S is determined, and the magnitude of the determination error probability of the error of the error estimator 102 with respect to the output signal 101S is generated and output as a determination signal 401S (step S).
302).

Hereinafter, a case where the input of the waveform equalizer 101 is a DTV signal will be described as an example. FIG. 5 shows the relationship between the determination signal 401S and the output signal 101S. 20 and 21, the segment synchronization signal 3103,
Since the symbol values of the PN 511 signal 3201 and PN 63 signal 3202 during the field synchronization are known in advance, no error determination error of the error estimating unit 102 with respect to the output signal 101S occurs. In this case, the error signal 102
Since S always indicates a correct value, the signal determination unit 401 outputs “0” as the determination signal 401S. The control signal 3203 is an eight-level DTV signal, and can take only two values.
The probability of occurrence of an error of error 02 is low. In this case, since the error signal 102S indicates a substantially correct value, the signal determination unit 401 outputs “1” as the determination signal 401S. Other signals are in the 8-level DTV signal,
Since all of the values can be taken, there is a high probability that the error estimation unit 102 makes an error determination error for the output signal 101S. In this case, since the probability that the error signal 102S indicates a correct value is low, the signal determination unit 401 outputs “2” as the determination signal 401S.

The step size determining unit 402 selects one of three types of step sizes set in advance according to the value of the determination signal 401S, and
Output S. When the determination signal 401S is "0", the largest step size is determined. When the determination signal 401S is "1", the second largest step size is determined.
If 1S is "2", the smallest step size is output as the step size 104S (step S30).
3). The coefficient update amount calculation unit 103 receives the error signal 102S, the step size 104S, and the data 105S, multiplies them, and updates the tap coefficient update amount 106S.
S is output (step S304). Then, the tap coefficient update amount 106S is used by the waveform equalizer 101 for updating the tap coefficient represented by (Equation 1).
Note that the processing in steps S301 to S304 and the update of the tap coefficient in the waveform equalizer 101 are performed by the waveform equalizer 1
This is repeated as long as the waveform equalization processing at 01 is performed.

As described above, according to the waveform equalization control device and the waveform equalization control method according to the second embodiment, the determination according to the probability of occurrence of an error determination error of error estimation section 102 with respect to output signal 101S occurs. A signal determination unit 401 that outputs a signal 401S and a step size determination unit 402 that outputs a preset step size corresponding to the determination signal 401S are provided according to the determination error probability of error estimation for the output signal 101S. Step size 1
04S can be switched, and when the error signal 102S is correct, the tap coefficient update amount 106S becomes large, so that the convergence speed can be improved, and the convergence speed is high and the stability at low C / N is stable. This has the effect that a waveform equalization control device having high reliability can be realized.

In the second embodiment, the input signal 10
The case where 0S is a DTV signal has been described, but the input is not limited to the DTV signal. Further, the determination signal 401S is set in three stages, but is not limited to this, and may be two stages or four or more stages. Further, the signal value of the determination signal 401S is not limited to “0”, “1”, or “2”. In addition, the selected step size 10
4S is not limited to three types, but may be two types or four or more types.

In the second embodiment, the signal determination unit 4
Although the case where 01 generates the determination signal 401S using the synchronization signal included in the input signal 100S has been described, the signal determination unit 401 may generate the determination signal 401S using the synchronization signal included in the output signal 101S. Good.

(Embodiment 3) The configuration of a waveform equalization control device according to Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 6 is a block diagram showing a configuration of the waveform equalization control device according to the third embodiment. In FIG. 6, the waveform equalization control device according to the third embodiment includes a waveform equalizer 101 that outputs an output signal 101S in which the transmission path distortion of the input signal 100S is reduced based on the LMS algorithm, An error estimating unit 102 for estimating an error and outputting it as an error signal 102S; an error signal 102S, a step size 104S, and data 10
A coefficient update amount calculation unit 103 for calculating a tap coefficient update amount 106S based on 5S, an error signal 102S, and a threshold 6
A step size determination unit 601 that receives a first step size setting value 602S, a first step size setting value 602S, and a second step size setting value 603S and generates and outputs a step size 104S. Step size determination unit 601
Further includes a comparator 602 and a selector 603.

Next, the operation of the waveform equalization control device according to the third embodiment will be described with reference to the drawings. FIG. 26 is a flowchart showing the operation of the waveform equalization control device according to the third embodiment.

Based on the output signal 101S output from the waveform equalizer 101, the error estimator 102 estimates an error to use for updating the tap coefficients, and outputs the estimated error as an error signal 102S (step S401). . The comparator 602 calculates the absolute value of the error signal 102S and the threshold 601S.
Are compared (step S402). From the comparison result of the comparator 602, the absolute value of the error signal 102S is equal to the threshold 601S.
In the following cases, the selector 603 selects the first step size setting value 602S and outputs it as the step size 104S. From the comparison result of the comparator 602, the error signal 10
If the absolute value of 2S exceeds the threshold 601S, the selector 6
03 is a second step size setting value 60 which is a step size larger than the first step size setting value 602S.
3S is selected and output as a step size 104S (step S403). Thus, step S402
And S403, the error signal 102S and the threshold 60
1S, the first step size setting value 602S, and the second
Is determined on the basis of the step size setting value 603S. Coefficient update amount calculation unit 10
3 receives the error signal 102S, the step size 104S, and the data 105S as inputs, performs a multiplication thereof,
The tap coefficient update amount 106S is output (step S40).
4). Then, the tap coefficient update amount 106S is used by the waveform equalizer 101 for updating the tap coefficient represented by (Equation 1). Steps S401 to S4
The process of step 04 and the update of the tap coefficients in the waveform equalizer 101 are repeated as long as the waveform equalizer 101 performs the waveform equalization process. The value of the threshold 601S is the error signal 1
When the absolute value of 02S is equal to or smaller than the threshold 601S, the value is set so that the waveform equalizer 101 is almost converged.

As described above, according to the waveform equalization control device and the waveform equalization control method according to the third embodiment, the step size determination unit 601 that switches the size of the step size 104S according to the magnitude of the error signal 102S is provided. With this arrangement, when the error is large, that is, when the waveform equalizer 101 has not yet converged, the convergence speed is improved by using a large step size, and the error is small, that is, the waveform equalizer 101 has almost converged. By using a small step size at the stage, stability at low C / N can be ensured, and there is an effect that a waveform equalization control device having a high convergence speed and high stability at low C / N can be realized.
In the third embodiment, the step size is switched in two stages. However, a plurality of threshold values may be input to the comparator 602, and three or more step sizes may be selected by the selector 603 according to the comparison result. .

(Embodiment 4) The configuration of a waveform equalization control apparatus according to Embodiment 4 of the present invention will be described with reference to the drawings. FIG. 7 is a block diagram showing the configuration of the waveform equalization control device according to the fourth embodiment. In FIG. 7, the waveform equalization control device according to the fourth embodiment includes a waveform equalizer 101 that outputs an output signal 101S in which the transmission line distortion of the input signal 100S is reduced based on the LMS algorithm, An error estimating unit 102 for estimating an error and outputting it as an error signal 102S; an error quantizing unit 701 for converting the error signal 102S to a quantized error signal 701S having a value of a power of 2 and outputting the same; 701
A coefficient update amount calculation unit 702 that calculates a tap coefficient update amount 106S based on S, a step size 104S, and data 105S used for coefficient update.

Next, the operation of the waveform equalization control device according to the fourth embodiment will be described with reference to the drawings. Waveform equalizer 1
The error estimating unit 102 estimates an error to use for updating the tap coefficients based on the output signal 101S output from the output signal 01, and outputs the estimated error as an error signal 102S. Error quantizing section 701 converts error signal 102S to a quantized error signal 701S having the same sign as 102S and the largest absolute value of 102S or less among powers of two, and outputs the result. FIG. 8 shows the relationship between the error signal 102S and the quantized error signal 701S obtained by converting the error signal 102S. If 102S is “0”, 701S is also “0”. The coefficient update amount calculation unit 702 calculates the quantization error signal 701
S, the step size 104S and the data 105S are input, and the quantization error signal 70 that takes only the value of the power of 2 or “0” instead of the conventional multiplication by two is used.
By using 1S, the process of multiplying the error can be substituted by a shift operation. Therefore, the multiplication and the single shift operation are used instead, and the tap coefficient update amount 106S is output.

As described above, according to the waveform equalization control device of the fourth embodiment, error quantizing section 701 converts error signal 102S to quantized error signal 7 having a power of 2 value.
01S, and the tap coefficient update amount 106S is determined using the quantization error signal 701S. Therefore, the coefficient update amount calculation unit 702 can replace the multiplication with the shift operation, and the coefficient update amount of one tap can be calculated. Since the number of multipliers for calculation can be reduced to one, the effect of reducing the circuit scale can be obtained.

In the fourth embodiment, the error signal 10
When the 2S is converted into the quantization error signal 701S, the conversion as shown in FIG. 8 is performed. The quantized error signal 701S having the minimum absolute value described above may be converted. It may be converted to a quantization error signal 701S having a close absolute value.

(Embodiment 5) The configuration of a waveform equalization control apparatus according to Embodiment 5 of the present invention will be described with reference to the drawings. FIG. 9 is a diagram showing a configuration of a waveform equalization control device according to the fifth embodiment. In FIG. 9, the waveform equalization control device according to the fifth embodiment includes a waveform equalizer 101 that outputs an output signal 101S in which the transmission line distortion of the input signal 100S is reduced based on the LMS algorithm, and an output signal 10S.
An error estimating unit 102 that estimates an error of 1S and outputs it as an error signal 102S;
Is converted into quantized data 901S having a value of a power of two, and is output.
S, step size 104S, and quantized data 901
And a coefficient update amount calculation unit 902 that calculates the tap coefficient update amount 106S based on S.

Next, the operation of the waveform equalization control device according to the fifth embodiment will be described with reference to the drawings. Waveform equalizer 1
The error estimating unit 102 estimates an error to use for updating the tap coefficients based on the output signal 101S output from the output signal 01, and outputs the estimated error as an error signal 102S. The data quantization unit 901 converts the data 105S to the power of 2 and the absolute value of the data
The quantized data 901S having a maximum absolute value of S or less is converted and output. FIG. 10 shows the relationship between the data 105S and the quantized data 901S obtained by converting the data 105S. When the data 105S is "0", the 901S is also set to "0". The coefficient update amount calculation unit 902 calculates the error signal 1
02S, step size 104S, and quantized data 901
The process of multiplying an error can be replaced with a shift operation by using quantized data 901S that takes only a power of two or "0" instead of the conventional process of performing two multiplications with S as an input. This is substituted by one multiplication and one shift operation, and the tap coefficient update amount 106
Output S.

As described above, according to the waveform equalization control device of the fifth embodiment, the data quantizing section 901 converts the data 105S used for updating the coefficients into the quantized data 901S having a power of two, Quantized data 901S
Is used to determine the tap coefficient update amount 106S, so that the coefficient update amount calculation unit 902 can replace the multiplication with a shift operation, and the number of multipliers for calculating the coefficient update amount for one tap is reduced to one. By doing so, the effect of achieving a reduction in circuit scale can be obtained.

In the fifth embodiment, when the data 105S used for updating the coefficients is converted into the quantized data 901S, the conversion as shown in FIG. 10 is performed.
5S may be converted into quantized data 901S having the same absolute value as that of the data 105S and having the minimum absolute value equal to or greater than the absolute value of the data 105S among the powers of 2,
The data 105S may be converted into quantized data 901S having the same sign as the data 105S and having the absolute value closest to the absolute value of the data 105S among the powers of two.

(Embodiment 6) The configuration of a waveform equalization control apparatus according to Embodiment 6 of the present invention will be described with reference to the drawings. FIG. 11 is a block diagram showing the configuration of the waveform equalization control device according to the sixth embodiment. In FIG. 11, the waveform equalization control device according to the sixth embodiment includes an input signal 100
A waveform equalizer 101 that outputs an output signal 101S in which the transmission line distortion of S is reduced based on the LMS algorithm;
An error estimating unit 102 that estimates an error of the output signal 101S and outputs the error as an error signal 102S;
4S is a quantization step size 11 having a power of 2 value 11
Step size quantization unit 11 that converts the output into 01S and outputs it
01, error signal 102S, quantization step size 11
01S and a coefficient update amount calculation unit 1102 that calculates a tap coefficient update amount 106S based on data 105S used for coefficient update.

Next, the operation of the waveform equalization control device according to the sixth embodiment will be described with reference to the drawings. Waveform equalizer 1
The error estimating unit 102 estimates an error to use for updating the tap coefficient based on the output signal 101S output from the output signal 01, and outputs the estimated error as an error signal 102S. The step size quantization unit 1101 converts the step size 104S into a quantization step size 1101S having a maximum value of 104S or less among powers of 2 and outputs the result. FIG. 12 shows the relationship between the step size 104S and the quantization step size obtained by converting the step size 104S. If 104S is “0”, 1101S is also “0”. The coefficient update amount calculation unit 1102 calculates the error signal 102S
, The quantization step size 1101S and the data 105S as inputs, and the processing conventionally performed by two multiplications is
By using the quantization step size 1101S that takes only the value of the exponent or “0”, the process of multiplying the error can be substituted by a shift operation. Tap coefficient update amount 106S
Is output.

As described above, according to the waveform equalization control apparatus of the sixth embodiment, the step size quantization section 1101
Is converted into a quantization step size 1101S having a value of a power of 2, and the tap coefficient update amount 1010S is calculated using the quantization step size 1101S.
Since 6S is determined, the coefficient update amount calculation unit 110
The multiplication can be replaced by a shift operation in 2 and 1
Since the number of multipliers for calculating the tap coefficient update amount can be reduced to one, an effect of reducing the circuit size can be obtained.

In the sixth embodiment, when the step size 104S is converted into the quantization step size 1101S, the conversion as shown in FIG. 12 is performed. 1
Quantization step size 11 having minimum value of 04S or more
01S or step size 1
04S may be converted to a quantization step size 1101S having a value closest to the step size 104S among powers of two.

(Embodiment 7) The configuration of a waveform equalization control apparatus according to Embodiment 7 of the present invention will be described with reference to the drawings. FIG. 13 is a block diagram showing a configuration of the waveform equalization control device according to the seventh embodiment. In FIG. 13, the waveform equalization control device according to the seventh embodiment includes input signal 100
A waveform equalizer 101 that outputs an output signal 101S in which the transmission line distortion of S is reduced based on the LMS algorithm;
An error estimating unit 1303 that estimates an error of the output signal 101S, and outputs an error signal 102S with the error corresponding to a predetermined range of the output signal among the estimated errors being 0;
An update timing signal 130 that receives the error signal 102S as input and controls the timing for calculating the tap coefficient update amount.
A coefficient update timing control unit 1301 that outputs 1S;
Error signal 102S, update timing signal 1301S, step size 104S, and data 1 used for coefficient update
A coefficient update amount calculation unit 1302 that calculates a tap coefficient update amount 106S based on the 05S.

Next, the operation of the waveform equalization control device according to the seventh embodiment will be described with reference to the drawings. FIG. 27 is a flowchart showing the operation of the waveform equalization control device according to the seventh embodiment. FIG. 14 is a diagram for explaining the timing of updating the tap coefficients of the waveform equalization control device according to the seventh embodiment.

An error estimating unit 1303 estimates an error for use in updating tap coefficients based on an output signal 101S output from the waveform equalizer 101, and generates and outputs an error signal 102S based on the estimated error. (Step S5
01). Here, the error estimating unit 1303 determines that Stop & G
An error signal 102S is created based on the o algorithm. The coefficient update timing control unit 1301 is configured as shown in FIG.
As shown in (1), a constant symbol interval from the previous coefficient update timing (here, n symbols are used, where n is 1)
And the error signal 102
The update timing signal 1301S is turned on at the first symbol where S is not "0". For other symbols, the update timing signal 1301S is turned off (Step S
502). The coefficient update amount calculation unit 1302 receives the error signal 102S, the step size 104S, and the data 105S only when the update timing signal 1301S is ON,
The multiplication is performed to output a tap coefficient update amount 106S (step S503). The tap coefficient update amount 106S is calculated by the waveform equalizer 101 according to (Equation 1).
Are used for updating the tap coefficient indicated by. Note that the processing of steps S501 to S503 and the update of the tap coefficient in the waveform equalizer 101 are performed by the waveform equalizer 10
This is repeated as long as the waveform equalization processing in step 1 is performed.

In the conventional waveform equalization control device, as shown in FIG. 14B, the coefficient update amount calculation unit taps at a constant symbol interval (here, n symbols are used, where n is an integer of 1 or more). The coefficient update amount 106S was output. S
When the error signal 102S is generated by using the top & Go algorithm, the error signal 102S output from the error estimating unit 1303 is approximately ２ as shown in FIG.
"0" with the probability of. The tap coefficient update amount 106S is-
Since α × e (n) × di (n), if the error signal 102S is “0”, that is, if e (n) = 0, the tap coefficient update amount 106S becomes “0”. That is, the coefficient update amount calculation unit performs the tap coefficient update amount 106S once every n symbols.
Is output, but about half of them are "0", and the substantial coefficient update interval is 2n symbols as shown in FIG. 14 (c). On the other hand, in the example of the seventh embodiment, FIG.
As shown in (d), the substantial coefficient update interval is (n + 1)
This is about the symbol, which is about half that of the conventional one.

As described above, according to the waveform equalization control device and the waveform equalization control method according to the seventh embodiment, the coefficient update amount controlling section 1302 controls the timing of calculating the tap coefficient update amount 106S. Timing control unit 13
By providing 01, there is an effect that the substantial coefficient update interval can be greatly reduced, and the convergence speed of the waveform equalizer 101 can be improved.

In the seventh embodiment, Stop & G
Although the description has been given of the waveform equalization control device using the o algorithm, the present invention is not limited to this.
That is, the present invention can also be used for a waveform equalization control device that may stop the coefficient update operation.

The coefficient update timing control section 1301 according to the seventh embodiment sets the update timing signal 13 at the first symbol after n or more symbols have elapsed from the previous coefficient update timing and the error signal 102S is not “0”.
It is not limited to the one that turns ON 01S. For example, the error signal 102S is monitored by a coefficient update timing control unit that turns on the update timing signal 1301S at the second symbol where n or more symbols have elapsed from the previous coefficient update timing and the error signal 102S is not “0”. The one that turns on the update timing signal 1301S by doing so is included in the scope of the present invention.

In the seventh embodiment, the timing of updating the coefficient is controlled by turning on or off the update timing signal 1301S, but the present invention is not limited to this. For example, the update timing of the tap coefficient may be controlled by changing the type of the identifier included in the update timing signal 1301S. Note that the “update timing signal 1301
"Generating S" is a broad concept including turning on or off the update timing signal 1301S.

(Eighth Embodiment) The configuration of a waveform equalization control device according to an eighth embodiment of the present invention will be described with reference to the drawings. FIG. 15 is a block diagram showing a configuration of the waveform equalization control device according to the eighth embodiment. In FIG. 15, the waveform equalization control device according to the eighth embodiment includes an input signal 100
A waveform equalizer 101 that outputs an output signal 101S in which the transmission line distortion of S is reduced based on the LMS algorithm;
An error of the output signal 101S is estimated, and an error signal 1502S
Error estimating section 1501 that outputs
2S, step size 104S, and tap coefficient update amount 106S based on data 105S used for coefficient update.
And a coefficient update amount calculation unit 103 that calculates The error estimating unit 1501 further receives the output signal 101S as an input and outputs an output error signal 1501S.
502, the output error signal 1501S, and the output signal 10
A coefficient update error generation unit 1503 that receives 1S as an input, reduces a partial section of the output error signal 1501S at a predetermined rate, and outputs an error signal 1502S.

Next, the operation of the waveform equalization control device according to the eighth embodiment will be described with reference to the drawings. Here, a case where the input of the waveform equalizer is a DTV signal is taken as an example. FIG. 28 is a flowchart showing the operation of the waveform equalization control device according to the eighth embodiment.

Output signal 1 output from waveform equalizer 101
Based on 01S, the output error estimating unit 1502 estimates an output error that is an error with the most probable symbol value, and generates an output error signal 1501S (step S601). The coefficient update error generation unit 1503 outputs the output error signal 1501S
As shown in FIG. 22B, a 25% value of the output error signal 1501S is generated as the error signal 1502S for the output error signal 1501S that outputs "0" in the Stop & Go algorithm as shown in FIG. Then, the data is output (step S602). FIG.
6 shows the relationship between the output error signal 1501S and the error signal 1502S. The coefficient update amount calculator 103 calculates the error signal 15
02S, step size 104S, and data 105S are input, multiplied by them, and the tap coefficient update amount 106S is output (step S603). Then, the tap coefficient update amount 106S is used by the waveform equalizer 101 for updating the tap coefficient represented by (Equation 1). Note that the processing of steps S601 to S603,
Updating of the tap coefficient in the waveform equalizer 101 is repeated as long as the waveform equalization process in the waveform equalizer 101 is performed.

As described above, according to the waveform equalization control device and the waveform equalization control method according to the eighth embodiment, the Stop
In the & Go algorithm, the coefficient update error generator converts the output error signal to “0” and outputs it as an error signal, but converts it to a value of 25% of the output error signal 1501S and outputs it as an error signal 1502S. The provision of the coefficient updating error generation unit 1503 has an effect that the number of error signals that can be used for updating the tap coefficients increases, and the convergence speed of the waveform equalizer 101 can be improved.

In the eighth embodiment, the input is DTV
Although the case of a signal has been described, the input is not limited to only the DTV signal. In addition, 25%, which is a ratio used when conversion is performed by the coefficient update error generation unit 1503,
Is not limited to this value.

(Embodiment 9) The configuration of a waveform equalization control apparatus according to Embodiment 9 of the present invention will be described with reference to the drawings. FIG. 17 is a block diagram showing a configuration of the waveform equalization control device according to the ninth embodiment. In FIG. 17, the waveform equalization control device according to the ninth embodiment
A waveform equalizer 101 that outputs an output signal 101S in which the transmission line distortion of S is reduced based on the LMS algorithm;
The error of the output signal 101S is estimated, and the error signal 1701S
Error estimator 1701 that outputs
1S, step size 104S, and tap coefficient update amount 106S based on data 105S used for coefficient update.
Coefficient calculation unit 103 for calculating the output signal
An error rate measurement circuit 1703 that measures the data error rate from S and outputs the error rate as an error signal 1702S.
And The error estimator 1701 further includes an output error estimator 1502 that receives the output signal 101S as an input and outputs an output error signal 1501S, and an output error signal 1501.
S, an output signal 101S, and an error signal 1702S, and a coefficient update error generation unit 1702 that outputs an error signal 1701S.

Next, the operation of the waveform equalization control device according to the ninth embodiment will be described with reference to the drawings. Here, a case where the input of the waveform equalizer 101 is a DTV signal is taken as an example. FIG. 29 is a flowchart showing the operation of the waveform equalization control device according to the ninth embodiment.

Output signal 1 output from waveform equalizer 101
The output error estimating unit 1502 estimates an output error from the most probable symbol value from 01S, and generates an output error signal 1501S (step S701). The error rate measurement circuit 1703 calculates the output signal 10 of the waveform equalizer 101.
If the error rate indicating the ratio of errors included in 1S becomes a predetermined value, for example, 10% or more, the error signal 1702
S is turned ON, otherwise, the error signal 170
2S is turned off (step S702). Here, the error rate measurement circuit 1703 measures the error rate using ECC data or ECC bits included in the output signal 101S.

The coefficient update error generation section 1702 outputs the output error signal 1501S, the output signal 101S, and the error signal 17
When 02S is input and the error signal 1702S is ON, a signal similar to the error signal shown in FIG. 22B is output based on the Stop & Go algorithm as before. On the other hand, when the error signal 1702S is OFF, the output error signal 1501S indicates an almost correct value.
The conversion based on the Stop & Go algorithm is stopped, and the value of the output error signal 1501S is used as the error signal 1701.
It is generated and output as S (step S703). FIG.
8 shows the relationship between the output error signal 1501S and the error signal 1701S when the error signal 1702S is OFF. The coefficient update amount calculation unit 103 receives the error signal 1701S, the step size 104S, and the data 105S, multiplies them, and outputs a tap coefficient update amount 106S (step S704). Then, the tap coefficient update amount 106S is used by the waveform equalizer 101 for updating the tap coefficient represented by (Equation 1). Note that the processing in steps S701 to S704 and the waveform equalizer 101
The update of the tap coefficient in is repeated as long as the waveform equalizer 101 performs the waveform equalization process.

As described above, according to the waveform equalization control device and the waveform equalization control method according to the ninth embodiment, the Stop
In the & Go algorithm, an error rate measurement circuit 1703 turns on or off the error signal 1702S according to the error rate of the output signal 101S, and an output error signal 1501 when the error signal 1702S is on.
A part of S is converted to “0” and output as an error signal 1701S, and when the error signal is OFF, conversion to “0” is stopped and the output error signal 1501S is output as it is. By having and,
The number of error signals 1701S that can be used for updating tap coefficients is increased, and the convergence speed of the waveform equalizer 101 can be improved.

In the ninth embodiment, the input is DTV.
Although the case of a signal has been described, the input is not limited to only the DTV signal. In addition, the error rate measurement circuit 1
The threshold value 703 of the error rate for switching ON and OFF of the error signal 1702S is set to 10%, but is not limited to this value.

When the error signal 1702S is ON, the coefficient update error generation section 1702 outputs the Stop & Go
Although the error signal 1701S is generated by an algorithm, the present invention is not limited to this. For example, when the error signal 1702S is ON, the coefficient update error generation unit may output the error signal 1502S shown in FIG.
When 2S is ON, the error signal 1701S output from the coefficient update error generation unit 1702 becomes the output error signal 1501S
If the output error signal 1501S is not the same as that described above, that is, if the output error signal 1501S is attenuated in a predetermined range or ratio, or is set to 0, it is included in the scope of the present invention.

In the ninth embodiment, the error signal 1
702S is ON or OFF by the error rate measurement circuit 1703
However, the present invention is not limited to this. For example, the type of the identifier included in the error signal 1702S may be changed to indicate whether the error rate is equal to or more than a predetermined value. In addition,
“Generating the error signal 1702S” is a broad concept including turning the error signal 1702S ON or OFF.

The output signal 101 of the waveform equalizer 101
S is an error correction unit (Forward Erro not shown)
r Correction Unit), the error rate measurement circuit included in the error correction unit is
The error rate measurement circuit 1703 according to the ninth embodiment may be used.

[0117]

【The invention's effect】

As described above, according to the waveform equalization control device of the first aspect of the present invention, the transmission line distortion of the input signal is reduced by LM.
A waveform equalizer that reduces based on the S algorithm,
What is claimed is: 1. A waveform equalization control device for controlling updating of a tap coefficient of a filter included in a waveform equalizer, comprising: an error estimator configured to estimate an error of the output signal from an output signal of the waveform equalizer and output the error as an error signal. And an input of an upper limit value and a lower limit value of the step size, which are the upper limit value and the lower limit value of the step size, which is a step of updating the error signal and the tap coefficient, and the lower limit value of the step size and the lower limit value of the step size. A step size of a size corresponding to the error signal in the above range is adaptively generated and output, based on a step size determining unit, the error signal, the step size, and data used for tap coefficient update. By providing a coefficient update amount calculation unit that calculates the amount of tap coefficient update, follow-up performance when the transmission line distortion of the input signal fluctuates and the convergence speed during the initial operation Fast and less sensitive to noise, the effect can be realized even higher waveform equalization control stability at low C / N is obtained.

According to the waveform equalization control device of the second aspect of the present invention, in the waveform equalization control device of the first aspect, the step size determining section squares the error signal. A multiplier for generating a square error, a square error storage unit for storing a square error generated at the time of updating the previous tap coefficient, a square error output from the multiplier, and storage for the square error storage unit A subtractor for generating a difference of a square error, which is a difference from a square error generated at the time of updating the previous tap coefficient, a first comparator for comparing the square error with a first threshold value, A second comparator for comparing the squared error with a second threshold,
A third comparator that compares the absolute value of the difference between the squared errors and a third threshold value, a step size storage unit that stores a step size used at the time of updating the previous tap coefficient, and a step size storage unit. Memorized step size,
The output of the first comparator, the output of the second comparator, the output of the third comparator, the upper limit of the step size, and the lower limit of the step size are input, By providing a step size increase / decrease unit that generates the step size used for tap coefficient update, the follow-up performance when the transmission line distortion of the input signal fluctuates and the convergence speed at the time of initial operation are fast, and the influence of noise Low C /
The effect of realizing a waveform equalization control device having high stability at the time of N is obtained.

According to a third aspect of the present invention, in the waveform equalization control device according to the second aspect, the second threshold is such that the square error is larger than the value. Is larger, the waveform equalizing operation of the waveform equalizer is a value that tends to diverge. If the square error is smaller than the value, the first threshold is equal to the waveform of the waveform equalizer. The third threshold value is a value in which either the convergence operation is converging or the convergence is completed. When the square error is smaller than the first threshold value, If the absolute value of the difference is greater than the third threshold, the waveform equalizer is in a state where the waveform equalization operation is converging. If the absolute value of the difference is equal to or smaller than the third threshold, the waveform equalization is performed. The step size increasing / decreasing unit is a value at which the waveform equalization operation of the detector is in a state where convergence is completed. From the comparison result of the third comparator,
When the square error is larger than the second threshold, the step size is reduced by a fixed amount, and when the square error is smaller than the first threshold and the absolute value of the difference of the square error is equal to or smaller than the third threshold, In some cases, the step size is reduced by a fixed amount. When the square error is smaller than a first threshold and the absolute value of the difference between the square errors is larger than a third threshold, the step size is fixed. In other cases, the step size is not changed, and the appropriate step size is set according to the state of the waveform equalizer. The convergence speed during operation is high, and it is hardly affected by noise.
The effect of realizing a waveform equalization control device having high stability at the time of N is obtained.

Further, according to the waveform equalization control device according to claim 4 of the present invention, in the waveform equalization control device according to claim 2, the second threshold is such that the square error is larger than the value. Is larger, the waveform equalizing operation of the waveform equalizer is a value that tends to diverge. If the square error is smaller than the value, the first threshold is equal to the waveform of the waveform equalizer. The third threshold value is a value in which either the convergence operation is converging or the convergence is completed. When the square error is smaller than the first threshold value, If the absolute value of the difference is greater than the third threshold, the waveform equalizer is in a state where the waveform equalization operation is converging. If the absolute value of the difference is equal to or smaller than the third threshold, the waveform equalization is performed. Is a value at which the waveform equalization operation of the detector is in a state of completion of convergence. Than compared result of the third comparator, 2
If the squared error is larger than the second threshold, the step size is reduced by a fixed ratio, the squared error is smaller than the first threshold, and the absolute value of the difference between the squared errors is equal to or smaller than a third threshold. In this case, the step size is reduced by a fixed ratio. If the square error is smaller than a first threshold and the absolute value of the difference between the square errors is larger than a third threshold, the step size is reduced by a fixed ratio. In other cases, the step size is not changed, and an appropriate step size is set according to the state of the waveform equalizer. The convergence speed during operation is fast, and it is hard to be affected by noise.
The effect of realizing a waveform equalization control device having high stability at low C / N is obtained.

Further, according to the waveform equalization control device according to the fifth aspect of the present invention, the waveform equalizer for reducing the transmission line distortion of the input signal based on the LMS algorithm is provided. A waveform equalization control device that controls updating of a tap coefficient of a filter, comprising: an error estimating unit that estimates an error of the output signal from an output signal of the waveform equalizer and outputs the error as an error signal; A signal determining unit that determines the magnitude of the estimation determination error probability and outputs a determination signal, and a value of a size according to the determination signal as a step size that is a step size of updating the tap coefficient as an input of the determination signal. And a coefficient update amount calculation unit that calculates a tap coefficient update amount based on the error signal, the step size, and data used for tap coefficient update. Thus, it is possible to increase the step size in accordance with the probability of the determination error of the output signal, and to perform the waveform equalization control in which the followability when the transmission distortion of the input signal fluctuates and the convergence speed at the time of the initial operation are fast. The effect of realizing the device is obtained.

Further, according to the waveform equalization control device according to claim 6 of the present invention, in the waveform equalization control device according to claim 5, the signal determination unit determines that the output signal is known. And the case where the probability of the determination error of the output signal is small, and the case where the probability of the determination error of the output signal is large. It is possible to increase or decrease the step size in accordance with the probability of a signal determination error. can get.

Further, according to the waveform equalization control device according to claim 7 of the present invention, in the waveform equalization control device according to claim 6, the step size determination section determines that the determination signal is the output signal. If it indicates that it is known, the first step size setting value is output as the step size, and if it indicates that the probability of the determination error of the output signal is small, it is smaller than the first step size setting value. A second step size setting value that is a value smaller than the second step size setting value is output when the probability of a determination error of the output signal is high. Output, it is possible to increase or decrease the step size according to the probability of the erroneous determination of the output signal, follow-up when the transmission distortion of the input signal fluctuates or during the initial operation The effect of flux rates can be achieved fast waveform equalization control device is obtained.

Further, according to the waveform equalizer control device of the eighth aspect of the present invention, the waveform equalizer for reducing the transmission line distortion of the input signal based on the LMS algorithm is provided. A waveform equalization control device that controls updating of a tap coefficient of a filter, comprising: an error estimating unit that estimates an error of the output signal from an output signal of the waveform equalizer and outputs the error signal as an error signal; And a plurality of step size setting values as inputs, a step size determining unit that determines a step size that is a step of updating the tap coefficient, the error signal, the step size, and data used for tap coefficient update. With the provision of the coefficient update amount calculation unit that calculates the tap coefficient update amount based on the threshold value, the step size can be selected from the relationship between the error signal and the threshold value. Convergence rate of the follow-up property and during the initial operation when the channel distortion of the issue varies is obtained the effect capable of realizing a fast waveform equalization controller.

According to a ninth aspect of the present invention, in the waveform equalization control apparatus according to the ninth aspect, the plurality of step size setting values are equal to the first step size setting value. And a second step size setting value having a value larger than the first step size setting value, wherein the step size determining unit compares the absolute value of the error signal with the threshold value, From the comparison result output from the comparator, the first step size setting value,
By selecting one of the second step size setting values and having a selector for outputting as the step size, a step size can be selected from a comparison result between the error signal and the threshold value, The effect of realizing a waveform equalization control device having a high follow-up property when the transmission path distortion of the input signal fluctuates and a fast convergence speed in the initial operation is obtained.

According to a waveform equalization control device according to a tenth aspect of the present invention, in the waveform equalization control device according to the ninth aspect, the threshold value is such that the absolute value of the error signal is equal to or smaller than the threshold value. When the waveform equalizer is in a state where the waveform equalizer is substantially converged, and the step size determining unit determines that the first step size setting value is equal to or smaller than the threshold value when the absolute value of the error signal is equal to or smaller than the threshold value. Output as a size, and when the absolute value of the error signal exceeds the threshold, the second
By outputting the step size setting value of the step size as the step size, from the comparison result between the error signal and the threshold value in the comparator, if it is determined that the waveform equalizer has not yet converged, a large step size Can be selected, and an effect of realizing a waveform equalization control device having a high follow-up property when the transmission path distortion of the input signal fluctuates and a fast convergence speed at the time of the initial operation is obtained.

Further, according to the waveform equalizer control device of the eleventh aspect of the present invention, the waveform equalizer for reducing the transmission line distortion of the input signal based on the LMS algorithm is provided. What is claimed is: 1. A waveform equalization control device for controlling updating of a tap coefficient of a filter, comprising: an error estimating unit for estimating an error of the output signal from an output signal of the waveform equalizer and outputting the error signal as an error signal; An error quantization unit that converts and outputs a quantization error signal having a value of a power of, the quantization error signal, a step size that is a step of updating the tap coefficient, and data used for updating the tap coefficient. In the related art, a coefficient update amount calculation unit for calculating the tap coefficient update amount is provided, so that two multiplication processes were conventionally required, but one multiplication and one shift operation can be substituted. Performance similar to Effect is obtained that can realize a small circuit scale waveform equalization control device while forms.

According to a twelfth aspect of the present invention, in the waveform equalization control apparatus according to the eleventh aspect, the error quantizing section converts the error signal into two.
Conventionally, two multiplications are required to determine the tap coefficient update amount by converting and outputting a quantized error signal having the same sign as the error signal and an absolute value having a maximum value equal to or smaller than the error signal. Is required, but one multiplication and one shift operation can be substituted, and the effect of realizing a waveform equalization control device with a small circuit scale while achieving the same performance as the conventional one can be obtained.

Further, according to the waveform equalization control device of the thirteenth aspect of the present invention, in the waveform equalization control device of the eleventh aspect, the error quantizing section converts the error signal into two.
Conventionally, two multiplications are required to obtain the tap coefficient update amount by converting and outputting a quantized error signal having the same sign as the error signal and an absolute value having a minimum value greater than or equal to the error signal. Is required, but one multiplication and one shift operation can be substituted, and the effect of realizing a waveform equalization control device with a small circuit scale while achieving the same performance as the conventional one can be obtained.

According to the waveform equalization control device of the fourteenth aspect of the present invention, the waveform equalizer for reducing the transmission line distortion of the input signal based on the LMS algorithm is provided. A waveform equalization control device that controls updating of a tap coefficient of a filter, comprising: an error estimating unit that estimates an error of the output signal from an output signal of the waveform equalizer and outputs the error signal as an error signal; A data quantizer for converting data to quantized data having a power of 2 and outputting the data, a tap size based on the error signal, a step size that is a step size of updating the tap coefficient, and the quantized data. With the provision of the coefficient update amount calculation unit for calculating the coefficient update amount, two multiplication processes were conventionally required, but one multiplication and one shift operation can be used instead, and The performance of Effect is obtained that can realize a small circuit scale waveform equalization controller while.

According to a waveform equalization control device according to a fifteenth aspect of the present invention, in the waveform equalization control device according to the fourteenth aspect, the data quantizing section transmits data used for updating the tap coefficients. The power of 2 is converted into quantized data having the same sign as the data used for updating the tap coefficients and having an absolute value equal to or less than the maximum value of the data used for updating the tap coefficients, and outputting the quantized data. Conventionally, two multiplication processes were required to obtain the value. However, one multiplication and one shift operation can be substituted, and a waveform equalization control device having a small circuit scale while achieving the same performance as the conventional one. Is obtained.

According to a waveform equalization control device according to a sixteenth aspect of the present invention, in the waveform equalization control device according to the fourteenth aspect, the data quantization unit converts data used for updating the tap coefficients. The power of 2 is converted into quantized data having the same sign as the data used for updating the tap coefficients and having an absolute value equal to or smaller than the data used for updating the tap coefficients, and outputting the quantized data. Conventionally, two multiplication processes were required to obtain the value. However, one multiplication and one shift operation can be substituted, and a waveform equalization control device having a small circuit scale while achieving the same performance as the conventional one. Is obtained.

Further, according to the waveform equalizer control apparatus of the seventeenth aspect of the present invention, the waveform equalizer for reducing the transmission line distortion of the input signal based on the LMS algorithm is provided. A waveform equalization control device that controls updating of a tap coefficient of a filter, an error estimating unit that estimates an error of the output signal from an output signal of the waveform equalizer and outputs the error as an error signal, and updates the tap coefficient. A step size quantization unit that converts a step size, which is a step size, into a quantization step size having a value of a power of 2 and outputs the error signal, the quantization step size, and data used for tap coefficient update. By providing a coefficient update amount calculation unit for calculating the tap coefficient update amount based on the above, conventionally, two multiplication processes were required, but one multiplication and one shift operation can be used instead. , The effect capable of realizing waveform equalization control circuit scale smaller while achieving the same performance as conventional can be obtained.

According to the waveform equalization control device of the eighteenth aspect of the present invention, in the waveform equalization control device of the seventeenth aspect, the step size quantization unit sets the step size to two. Conventionally, two multiplication processes were required to obtain the tap coefficient update amount by converting the power to a quantization step size having a maximum value equal to or less than the step size and outputting the result. Multiplication and one shift operation can be substituted, and the effect of realizing a waveform equalization control device with a small circuit scale while achieving the same performance as the conventional one can be obtained.

According to a waveform equalization control device according to a nineteenth aspect of the present invention, in the waveform equalization control device according to the seventeenth aspect, the step size quantization section sets the step size to two. Conventionally, it was necessary to perform two multiplication processes to obtain the tap coefficient update amount by converting the power to a quantization step size having a minimum value equal to or larger than the step size and outputting the result. Multiplication and one shift operation can be substituted, and the effect of realizing a waveform equalization control device with a small circuit scale while achieving the same performance as the conventional one can be obtained.

Further, according to the waveform equalization control device of the twentieth aspect of the present invention, there is provided the waveform equalizer for reducing the transmission path distortion of the input signal based on the LMS algorithm, and the waveform equalizer has A waveform equalization control device that controls updating of a tap coefficient of a filter, and estimates an error of the output signal from an output signal of the waveform equalizer, and among the estimated errors,
An error estimating unit that outputs an error signal with an error corresponding to a predetermined range of the output signal being 0, the error signal, a step size that is a step of updating the tap coefficient, and data used for updating the tap coefficient. A coefficient update amount calculation unit that calculates a tap coefficient update amount based on the error signal, and an update timing signal that controls a timing at which the coefficient update amount calculation unit calculates a tap coefficient update amount at a plurality of symbol intervals. A coefficient update timing control section for outputting the signal, the coefficient update amount calculation section calculates a tap coefficient update amount when the error signal is not “0”, thereby performing a coefficient update at a predetermined symbol interval. It is possible to shorten the coefficient update interval compared to the generalized control device,
As a result, it is possible to achieve an effect that a waveform equalization control device having a high follow-up property when the transmission line distortion of the input signal fluctuates and a fast convergence speed in the initial operation can be realized.

Further, according to the waveform equalization control device according to claim 21 of the present invention, in the waveform equalization control device according to claim 20, the coefficient update timing control unit is configured such that the coefficient update amount calculation unit By controlling the timing of calculating the tap coefficient update amount to the first symbol time after a predetermined symbol interval has elapsed from the previous timing and the error signal is not zero, the coefficient is calculated when the error signal is not "0". By calculating the tap coefficient update amount in the update amount calculation unit, the coefficient update interval can be reduced as compared with a waveform equalization control device that updates the coefficient at a predetermined symbol interval, and the transmission path of the input signal can be shortened. The effect of realizing a waveform equalization control device with a high follow-up property when the distortion fluctuates and a fast convergence speed at the time of the initial operation is obtained.

Further, according to the waveform equalization control device of the present invention, there is provided a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and the waveform equalizer has A waveform equalization control device that controls updating of a tap coefficient of a filter, an output error estimation unit that receives an output signal of the waveform equalizer as an input, and outputs an output error signal, and the output error signal and the output signal. , And a part of the output error signal is reduced at a fixed rate,
An error estimating unit having a coefficient updating error generating unit that outputs an error signal, a tap coefficient update amount based on the error signal, a step size that is a step size of updating the tap coefficient, and data used for updating the tap coefficient. And a coefficient update amount calculating section for calculating the output error signal, which has been converted to “0” by the coefficient updating error generating section, is converted into an error signal having a smaller value by multiplying the output error signal by a fixed ratio. By St
Compared to the op & Go algorithm, the number of error signals that can be used for updating the tap coefficients increases, and the effect of realizing a waveform equalization control device that has a high follow-up performance when the transmission line distortion of the input signal fluctuates and a fast convergence speed at the time of the initial operation is obtained. .

Further, according to the waveform equalization control device of the present invention, there is provided a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and the waveform equalizer has What is claimed is: 1. A waveform equalization control device for controlling updating of a tap coefficient of a filter, comprising: an error rate measurement circuit that receives an output signal of the waveform equalizer and generates an error signal indicating a ratio of an error included in the output signal. An output error estimating unit that receives an output signal of the waveform equalizer as an input and outputs an output error signal, and a coefficient update that receives the output error signal, the output signal and the error signal as inputs, and outputs an error signal A tap coefficient update amount based on an error estimating section having a use error generating section, the error signal, a step size as a step of updating the tap coefficient, and data used for updating the tap coefficient. By and a coefficient update amount calculation unit for, it becomes possible to update interval of the tap coefficients is shortened,
Further, by increasing the number of error signals that can be used for updating the tap coefficients, it is possible to obtain an effect of realizing a waveform equalization control device having a high follow-up performance when the transmission line distortion of the input signal fluctuates and a high convergence speed at the time of initial operation.

According to a waveform equalization control device according to a twenty-fourth aspect of the present invention, in the waveform equalization control device according to the twenty-third aspect, the coefficient update error generating section outputs the output signal based on the error signal. When detecting that the ratio of the error included in the signal is smaller than a predetermined ratio, by outputting the same value as the output error signal as the error signal, the update interval of the tap coefficient is shortened, and , The more error signals that can be used to update tap coefficients,
The effect of realizing a waveform equalization control device having a high follow-up property when the transmission path distortion of the input signal fluctuates and a fast convergence speed at the time of the initial operation is obtained.

According to the waveform equalization control method of the twenty-fifth aspect of the present invention, the update of the tap coefficient of the filter included in the waveform equalizer for reducing the transmission path distortion of the input signal based on the LMS algorithm is controlled. An error estimating step of estimating an error of the output signal from an output signal of the waveform equalizer and generating an error signal, and updating the tap coefficient based on the error signal. A step size determining step of adaptively determining a step size in a range not more than a step size upper limit value which is an upper limit value of a step size which is a step size and not less than a step size lower limit value which is a lower limit value of the step size; A signal, the step size, and a coefficient update amount calculating step of calculating a tap coefficient update amount based on data used for tap coefficient update; With this configuration, the waveform equalization has a high follow-up property when the transmission line distortion of the input signal fluctuates, a high convergence speed at the time of initial operation, is less affected by noise, and has a high stability at a low C / N. The effect of realizing the control method is obtained.

According to a waveform equalization control method according to claim 26 of the present invention, in the waveform equalization control method according to claim 25, the step size determination step includes squaring the error signal. A multiplication step for generating a square error, a subtraction step for generating a difference of a square error that is a difference between the square error generated at the time of updating the previous tap coefficient and the square error generated in the multiplication step; A first comparing step of comparing the squared error with a first threshold, a second comparing step of comparing the squared error with a second threshold, an absolute value of a difference between the squared error and a third A third comparison step of comparing with the threshold value of the above, a step size used at the time of the previous update of the tap coefficient, a comparison result of the first comparison step, a comparison result of the second comparison step, Third
And a step size generating step of generating a step size to be used for the current tap coefficient update based on the comparison result in the comparing step, the step size upper limit value, and the step size lower limit value. ,
It is possible to realize a waveform equalization control method which has a high follow-up performance when the transmission line distortion of the input signal fluctuates and a fast convergence speed at the time of initial operation, is hardly affected by noise, and has high stability at low C / N. The effect is obtained.

According to the waveform equalization control method of the present invention, the update of the tap coefficient of the filter included in the waveform equalizer for reducing the transmission path distortion of the input signal based on the LMS algorithm is controlled. A method for estimating an error of the output signal from an output signal of the waveform equalizer and generating an error signal, and determining a magnitude of a determination error probability of the error estimation for the output signal. Generating a determination signal; determining a step size, which is a step of updating the tap coefficient, based on the determination signal; the error signal; the step size; and data used for updating the tap coefficient. And calculating the tap coefficient update amount based on the above, thereby increasing the step size in accordance with the probability of the determination error of the output signal. Is possible, trackability and effects the convergence rate during the initial operation can be realized fast waveform equalization control method when channel distortion of the input signal varies can be obtained.

According to the waveform equalization control method of the twenty-eighth aspect of the present invention, the update of the tap coefficient of the filter included in the waveform equalizer that reduces the transmission line distortion of the input signal based on the LMS algorithm is controlled. An error estimating step of estimating an error of the output signal from an output signal of the waveform equalizer and generating an error signal; and an error signal, a threshold value, and a plurality of step size setting values. A step size determination step of determining a step size that is a step of updating the tap coefficient, based on the error signal, the step size, and a tap coefficient update amount based on data used for the tap coefficient update. With the step of calculating the coefficient update amount to be calculated, the step size can be selected from the relationship between the error signal and the threshold value, and the input signal Convergence rate of the follow-up property and during the initial operation when the channel distortion of fluctuates is obtained an effect that can realize fast waveform equalization control method.

According to a waveform equalization control method according to claim 29 of the present invention, in the waveform equalization control method according to claim 28, the plurality of step size setting values are set to the first step size.
And a second step size setting value larger than the first step size setting value, wherein the step size determination step includes comparing the absolute value of the error signal with the threshold value. And a selecting step of selecting one of the first step size setting value and the second step size setting value as the step size based on a comparison result in the comparing step. Thus, a step size can be selected from the comparison result between the error signal and the threshold value, and the waveform equalization control method has a high follow-up property when the transmission line distortion of the input signal fluctuates and a high convergence speed during the initial operation. Is obtained.

According to the waveform equalization control method according to claim 30 of the present invention, the update of the tap coefficient of the filter included in the waveform equalizer that reduces the transmission line distortion of the input signal based on the LMS algorithm is controlled. A method for estimating an error of the output signal from an output signal of the waveform equalizer, and setting an error corresponding to a predetermined range of the output signal to 0 among the estimated errors. An error estimation step of generating a signal, a coefficient update timing control step of generating an update timing signal for controlling a timing of calculating a tap coefficient update amount at a plurality of symbol intervals based on the error signal, and the error signal; A tap controlled by the update timing signal based on a step size that is a step of updating the tap coefficient and data used for updating the tap coefficient. A coefficient update amount calculating step of calculating a tap coefficient update amount by performing a predetermined symbol interval by calculating a tap coefficient update amount in the coefficient update amount calculation step when the error signal is not “0”. It is possible to shorten the coefficient update interval as compared with the waveform equalization control method that updates the coefficient by using, and the follow-up performance when the transmission line distortion of the input signal fluctuates and the convergence speed at the time of initial operation are fast, waveform equalization The effect of realizing the control method is obtained.

According to a waveform equalization control method according to claim 31 of the present invention, in the waveform equalization control method according to claim 30, in the coefficient update timing control step,
By generating an update timing signal that sets the timing for calculating the tap coefficient update amount to be the first symbol time when a predetermined symbol interval has elapsed from the previous timing and the error signal is not 0, the error signal becomes “0”. ”, The tap coefficient update amount is calculated in the coefficient update amount calculation step, so that the coefficient update interval can be reduced as compared with a waveform equalization control method in which the coefficient is updated at a predetermined symbol interval. The tracking performance when the transmission line distortion of the input signal fluctuates and the convergence speed during the initial operation are fast,
The effect of realizing the waveform equalization control method is obtained.

According to the waveform equalization control method of the thirty-second aspect of the present invention, the update of the tap coefficient of the filter included in the waveform equalizer for reducing the transmission line distortion of the input signal based on the LMS algorithm is controlled. Estimating an output error from an output signal of the waveform equalizer, and generating an output error signal, based on the output error signal and the output signal. Generating an error signal in which a partial section of the signal is reduced at a fixed rate; and updating the tap coefficient based on the error signal, a step size that is a step size for updating the tap coefficient, and data used for updating the tap coefficient. The step of calculating the amount reduces the value by multiplying the output error signal, which has been converted to "0" in the step of generating the error signal for updating the coefficient, by a certain ratio. Waveform equalization control that increases the number of error signals that can be used to update tap coefficients compared to the Stop & Go algorithm by converting the error signal into a corrected error signal, and that follows up when the transmission line distortion of the input signal fluctuates and converges quickly during the initial operation. The effect of realizing the method is obtained.

According to the waveform equalization control method of the thirty-third aspect of the present invention, the update of the tap coefficient of the filter included in the waveform equalizer that reduces the transmission line distortion of the input signal based on the LMS algorithm is controlled. An output error estimating step of estimating an output error from an output signal of the waveform equalizer and generating an output error signal,
An error signal generating step of generating an error signal indicating an error rate included in the output signal of the waveform equalizer; and an error used for tap coefficient update based on the output error signal, the output signal, and the error signal. A coefficient update error generating step of generating a signal, a coefficient update amount for calculating a tap coefficient update amount based on the error signal, a step size that is a step size of the tap coefficient update, and data used for tap coefficient update. By having a calculation step,
Since the tap coefficient update interval is shortened and the error signal that can be used for tap coefficient update is increased, the follow-up performance when the transmission line distortion of the input signal fluctuates and the convergence speed during the initial operation are fast. The effect of realizing the equalization control method is obtained.

According to a waveform equalization control method according to a thirty-fourth aspect of the present invention, in the waveform equalization control method according to the thirty-third aspect, in the error generation step for updating coefficients, the error signal is used to output the error signal. When detecting that the ratio of the error included in the signal is smaller than a predetermined ratio, by generating the same value as the output error signal as the error signal, the update interval of the tap coefficient is reduced, and By increasing the number of error signals that can be used for updating the tap coefficients, an effect of realizing a waveform equalization control method with a high follow-up property when the transmission path distortion of the input signal fluctuates and a high convergence speed at the time of the initial operation is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a waveform equalization control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a step size determining unit according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram for explaining an operation of a step size increasing / decreasing unit according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a waveform equalization control device according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a relationship between a determination signal and an output signal of a waveform equalization control device according to a second embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration of a waveform equalization control device according to a third embodiment of the present invention.

FIG. 7 is a block diagram illustrating a configuration of a waveform equalization control device according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing a relationship between an error signal and a quantization error signal of a waveform equalization control device according to a fourth embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a waveform equalization control device according to a fifth embodiment of the present invention.

FIG. 10 is a diagram showing a relationship between data of a waveform equalization control device according to a fifth embodiment of the present invention and quantized data.

FIG. 11 is a block diagram showing a configuration of a waveform equalization control device according to a sixth embodiment of the present invention.

FIG. 12 is a diagram illustrating a relationship between a step size and a quantization step size of the waveform equalization control device according to the sixth embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a waveform equalization control device according to a seventh embodiment of the present invention.

FIG. 14 is an explanatory diagram for explaining a timing of updating a tap coefficient of the waveform equalization control device according to the seventh embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a waveform equalization control device according to an eighth embodiment of the present invention.

FIG. 16 is an explanatory diagram illustrating an operation of the waveform equalization control device according to the eighth embodiment of the present invention.

FIG. 17 is a block diagram showing a configuration of a waveform equalization control device according to a ninth embodiment of the present invention.

FIG. 18 is an explanatory diagram illustrating an operation of a waveform equalization control device according to a ninth embodiment of the present invention.

FIG. 19 is a block diagram showing a configuration of a conventional waveform equalization control device.

FIG. 20 is a diagram illustrating a configuration of a DTV signal format.

FIG. 21 is a diagram illustrating a configuration of a field synchronization signal format in a DTV signal.

FIG. 22 is an explanatory diagram for explaining an operation of a conventional waveform equalization control device.

FIG. 23 is a flowchart showing an operation of the waveform equalization control device according to the first embodiment of the present invention.

FIG. 24 is a flowchart showing an operation of the waveform equalization control device according to the first embodiment of the present invention.

FIG. 25 is a flowchart showing an operation of the waveform equalization control device according to the second embodiment of the present invention.

FIG. 26 is a flowchart showing an operation of the waveform equalization control device according to the third embodiment of the present invention.

FIG. 27 is a flowchart showing an operation of the waveform equalization control device according to the seventh embodiment of the present invention.

FIG. 28 is a flowchart showing an operation of the waveform equalization control device according to the eighth embodiment of the present invention.

FIG. 29 is a flowchart showing an operation of the waveform equalization control device according to the ninth embodiment of the present invention.

[Explanation of symbols]

101 Waveform equalizer 102, 1303, 1501, 1701, 1901 Error estimating unit 103, 702, 902, 1102, 1302 Coefficient update amount calculating unit 104, 402, 601 Step size determining unit 201 Multiplier 202 Square error storing unit 203 Subtractor 204 First comparator 205 Second comparator 206 Third comparator 207 Step size storage unit 208 Step size increase / decrease unit 401 Signal decision unit 602 Comparator 603 Selector 701 Error quantization unit 901 Data quantization unit 1101 Step size quantizer 1301 Coefficient update timing controller 1502 Output error estimator 1503, 1702, 1902 Coefficient update error generator 1703 Error rate measurement circuit 3101 Data signal 3102 Field synchronization 3103 Segment synchronization 3201 PN5 1 signal 3203 PN63 signal 3203 control signal 101S output signal 102S, 1502S, 1701S, 1901S error signal 104S step size 105S data 106S tap coefficient update amount 107S step size upper limit 108S step size lower limit 201S square error 202S square error difference 401S judgment signal 601S threshold value 602S first step size setting value 603S second step size setting value 701S quantization error signal 901S quantization data 1101S quantization step size 1301S update timing signal 1501S output error signal 1702S error signal

Claims (34)

[Claims] 1. A waveform equalization control device comprising a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and controlling updating of tap coefficients of a filter included in the waveform equalizer. An error estimating unit that estimates an error of the output signal from the output signal of the waveform equalizer and outputs the error signal as an error signal; and an upper limit value and a lower limit value of a step size that is a step of updating the error signal and the tap coefficient. A step size upper limit value and a step size lower limit value are input, and a step size of a size corresponding to the error signal is adaptively generated and output in a range equal to or smaller than the step size upper limit value and equal to or larger than the step size lower limit value. A step size determining unit, a coefficient update for calculating a tap coefficient update amount based on the error signal, the step size, and data used for the tap coefficient update. A waveform equalization control device, comprising: a quantity calculation unit. 2. The waveform equalization control device according to claim 1, wherein the step size determination unit generates a square error by squaring the error signal, and generates a square error when the tap coefficient is updated last time. A square error storage unit for storing the obtained square error, and a difference between the square error output from the multiplier and the square error generated at the time of updating the previous tap coefficient stored in the square error storage unit. A subtractor that generates a difference of the squared error, a first comparator that compares the squared error with a first threshold, a second comparator that compares the squared error with a second threshold, A third comparator for comparing the absolute value of the difference between the square errors with a third threshold value, a step size storage unit for storing a step size used at the time of updating the previous tap coefficient, and a step size storage unit Is compared with the stored step size in the first comparison. The output of the comparator, the output of the second comparator, the output of the third comparator, the upper limit value of the step size, and the lower limit value of the step size are used as inputs and used for updating the tap coefficients at this time. A waveform equalization control device, comprising: a step size increasing / decreasing unit configured to generate a step size. 3. The waveform equalization control device according to claim 2, wherein the second threshold value is such that the waveform equalization operation of the waveform equalizer tends to diverge if the square error is larger than the value. When the square error is smaller than the value, the first threshold is in a state where the waveform equalization operation of the waveform equalizer is converging or the convergence is completed. The third threshold value is the waveform, if the square error is smaller than the first threshold value, and if the absolute value of the difference between the square errors is larger than the third threshold value, A value at which the waveform equalization operation of the equalizer is in a convergence state, and a value at which the waveform equalization operation of the waveform equalizer is in a convergence completed state if the value is equal to or less than the third threshold value. The step size increasing / decreasing unit sets the square error to a second threshold based on the comparison result of the first to third comparators. If larger, the step size is reduced by a fixed amount. If the square error is smaller than a first threshold and the absolute value of the difference between the square errors is equal to or smaller than a third threshold, the step size is fixed. If the square error is smaller than a first threshold and the absolute value of the difference between the square errors is larger than a third threshold, the step size is increased by a certain amount. Is a waveform equalization control device, wherein a step size is not changed. 4. The waveform equalization control device according to claim 2, wherein the second threshold value is such that the waveform equalization operation of the waveform equalizer tends to diverge if the square error is larger than the value. When the square error is smaller than the value, the first threshold is in a state where the waveform equalization operation of the waveform equalizer is converging or the convergence is completed. The third threshold value is the waveform, if the square error is smaller than the first threshold value, and if the absolute value of the difference between the square errors is larger than the third threshold value, A value at which the waveform equalization operation of the equalizer is in a convergence state, and a value at which the waveform equalization operation of the waveform equalizer is in a convergence completed state if the value is equal to or less than the third threshold value. The step size increasing / decreasing unit sets the square error to a second threshold based on the comparison result of the first to third comparators. If it is larger, the step size is reduced by a fixed ratio. If the square error is smaller than a first threshold and the absolute value of the difference between the square errors is equal to or smaller than a third threshold, the step size is fixed. When the square error is smaller than a first threshold value and the absolute value of the difference between the square errors is larger than a third threshold value, the step size is increased by a fixed ratio. A waveform equalization control device, wherein a step size is not changed. 5. A waveform equalization control device comprising a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and controlling updating of tap coefficients of a filter included in the waveform equalizer. An error estimating unit for estimating an error of the output signal from the output signal of the waveform equalizer and outputting the error signal as an error signal; a signal for determining the magnitude of a determination error probability of error estimation for the output signal and outputting a determination signal A determining unit, a step size determining unit that receives the determination signal as an input, and outputs a value corresponding to the determination signal as a step size that is a step size of updating the tap coefficient, the error signal, and the step size And a coefficient update amount calculation unit that calculates a tap coefficient update amount based on data used for tap coefficient update, a waveform equalization control device. 6. The waveform equalization control device according to claim 5, wherein the signal determination unit indicates that the output signal is known and that the probability of a determination error of the output signal is small. The waveform equalization control device outputs three types of determination signals: a case and a case indicating that the probability of a determination error in the output signal is large. 7. The waveform equalization control device according to claim 6, wherein the step size determination unit sets a first step size setting value when the determination signal indicates that the output signal is known. Outputting as the step size, outputting a second step size setting value smaller than the first step size setting value when indicating that the probability of the determination error of the output signal is small; And a third step size setting value that is smaller than the second step size setting value is output when it indicates that the determination error probability is large. 8. A waveform equalization control device comprising a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and controlling updating of tap coefficients of a filter included in the waveform equalizer. An error estimator for estimating an error of the output signal from an output signal of the waveform equalizer and outputting the error signal as an error signal; inputting the error signal, a threshold value, and a plurality of step size setting values, and updating the tap coefficients. A step size determining unit that determines a step size that is a step of, a coefficient update amount calculating unit that calculates a tap coefficient update amount based on the error signal, the step size, and data used for tap coefficient update. A waveform equalization control device, characterized in that: 9. The waveform equalization control device according to claim 8, wherein the plurality of step size setting values are a first step size setting value and a second step size setting value larger than the first step size setting value. A step size setting value, wherein the step size determining unit compares the absolute value of the error signal with the threshold value, and sets the first step size setting value based on a comparison result output from the comparator. And a selector for selecting one of the second step size setting value and the second step size setting value and outputting the selected value as the step size. 10. The waveform equalization control device according to claim 9, wherein the threshold value is a value at which the waveform equalizer substantially converges when the absolute value of the error signal is equal to or less than the threshold value. The step size determining unit outputs the first step size setting value as the step size when the absolute value of the error signal is equal to or smaller than the threshold, and when the absolute value of the error signal exceeds the threshold. And outputting the second step size setting value as the step size. 11. A waveform equalization control device comprising a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and controlling updating of tap coefficients of a filter included in the waveform equalizer. An error estimator for estimating an error of the output signal from the output signal of the waveform equalizer and outputting the error signal as an error signal; and an error quantizer for converting the error signal into a quantization error signal having a power of 2 and outputting the same. And a coefficient update amount calculation unit that calculates a tap coefficient update amount based on the quantization error signal, a step size that is a step of updating the tap coefficient, and data used for the tap coefficient update. A waveform equalization control device, characterized in that: 12. The waveform equalization control device according to claim 11, wherein the error quantizing section sets the error signal to have the same sign as the error signal in a power of 2 and an absolute value equal to or smaller than the error signal. A waveform equalization control device, which converts the signal into a quantization error signal having the maximum value of the following and outputs the signal. 13. The waveform equalization control device according to claim 11, wherein the error quantization unit sets the error signal to have the same sign as the error signal in a power of 2 and an absolute value equal to or larger than the error signal. A waveform equalization control device, which converts the signal into a quantization error signal having a minimum value of and outputs the signal. 14. A waveform equalization control device comprising a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and controlling updating of tap coefficients of a filter included in the waveform equalizer. An error estimator for estimating an error of the output signal from an output signal of the waveform equalizer and outputting the error signal as an error signal; and converting data used for tap coefficient update into quantized data having a value of a power of 2 and outputting the same. A data quantizing unit; and a coefficient update amount calculating unit that calculates a tap coefficient update amount based on the error signal, a step size that is a step of updating the tap coefficient, and the quantized data. A waveform equalization control device. 15. The waveform equalization control device according to claim 14, wherein the data quantization unit sets the data used for updating the tap coefficients to have the same sign as data used for updating the tap coefficients among powers of two. A waveform equalization control device, which converts the absolute value into quantized data having a maximum value equal to or less than the data used for updating the tap coefficient and outputs the quantized data. 16. The waveform equalization control device according to claim 14, wherein the data quantization unit sets the data used for updating the tap coefficients to have the same sign as the data used for updating the tap coefficients among powers of two. A waveform equalization control device that converts the absolute value into quantized data having a minimum value equal to or greater than the data used for updating the tap coefficient and outputs the quantized data. 17. A waveform equalization control device comprising a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and controlling updating of tap coefficients of a filter included in the waveform equalizer. An error estimator for estimating an error of the output signal from the output signal of the waveform equalizer and outputting the error as an error signal; and a quantization step having a step size, which is a step of updating the tap coefficient, having a power of 2 value. A step size quantization unit that converts the size into a size and outputs the size, and a coefficient update amount calculation unit that calculates a tap coefficient update amount based on the error signal, the quantization step size, and data used for tap coefficient update. A waveform equalization control device, characterized in that: 18. The waveform equalization control device according to claim 17, wherein the step size quantizing unit sets the step size to a maximum of a step value smaller than the step size among powers of two. A waveform equalization control device, which converts and outputs the result. 19. The waveform equalization control device according to claim 17, wherein the step size quantizing unit sets the step size to a minimum value equal to or greater than the step size among powers of two. A waveform equalization control device, which converts and outputs the result. 20. A waveform equalization control device that includes a waveform equalizer that reduces transmission line distortion of an input signal based on an LMS algorithm, and controls updating of tap coefficients of a filter included in the waveform equalizer. An error estimating unit that estimates an error of the output signal from an output signal of the waveform equalizer, and outputs an error signal with an error corresponding to a predetermined range of the output signal being 0 among the estimated errors; The error signal, a step size that is a step of updating the tap coefficient, a coefficient update amount calculation unit that calculates a tap coefficient update amount based on data used for tap coefficient update, and the error signal as an input, A coefficient update timing control unit that outputs an update timing signal for controlling a timing at which the coefficient update amount calculation unit calculates the tap coefficient update amount at a plurality of symbol intervals. Waveform equalization controller according to. 21. The waveform equalization control device according to claim 20, wherein the coefficient update timing control unit sets a timing at which the coefficient update amount calculation unit calculates a tap coefficient update amount to a predetermined symbol from a previous timing. A waveform equalization control device, wherein the control is performed at a first symbol time when an interval has elapsed and the error signal is not zero. 22. A waveform equalization control device comprising a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and controlling updating of tap coefficients of a filter included in the waveform equalizer. An output error estimator that receives an output signal of the waveform equalizer as an input and outputs an output error signal, and an input of the output error signal and the output signal, and a partial interval of the output error signal is set at a constant rate. An error estimating unit having a coefficient updating error generating unit that outputs an error signal to reduce the error signal, a tap size that is a step size of updating the tap coefficient, and tapping based on data used for tap coefficient updating. A waveform equalization control device, comprising: a coefficient update amount calculation unit that calculates a coefficient update amount. 23. A waveform equalization control device comprising a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, and controlling updating of tap coefficients of a filter included in the waveform equalizer. An error rate measurement circuit that receives an output signal of the waveform equalizer as an input and generates an error signal indicating an error rate included in the output signal, and an output error signal that receives an output signal of the waveform equalizer as an input An output error estimating unit that outputs the error signal, the output signal, the output signal, and the error signal, and an error estimating unit that includes a coefficient update error generating unit that outputs an error signal. A coefficient update amount calculating unit that calculates a tap coefficient update amount based on a step size that is a step of updating the tap coefficient and data used for updating the tap coefficient. Equalization controller. 24. The waveform equalization control device according to claim 23, wherein the coefficient updating error generating unit detects that a ratio of an error included in the output signal is smaller than a predetermined ratio by the error signal. In this case, the same value as the output error signal is output as the error signal. 25. A waveform equalization control method for controlling updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, comprising: An error estimation step of estimating an error of the output signal from the signal and generating an error signal, based on the error signal, a step size upper limit value that is an upper limit value of a step size that is a step of updating the tap coefficient, And a step size determining step of adaptively determining a step size in a range equal to or larger than a step size lower limit value that is a lower limit value of the step size, based on the error signal, the step size, and data used for tap coefficient update. A coefficient update amount calculating step of calculating a tap coefficient update amount by using the waveform equalization control method. 26. The waveform equalization control method according to claim 25, wherein the step size determination step includes: a multiplication step of squaring the error signal to generate a square error; A subtraction step of generating a difference of a square error, which is a difference between the square error thus obtained and the square error generated in the multiplication step; a first comparison step of comparing the square error with a first threshold value; A second comparison step of comparing the square error with a second threshold value, a third comparison step of comparing the absolute value of the difference of the square error with a third threshold value, and a previous tap coefficient. The step size used when updating,
The comparison result in the first comparison step, the comparison result in the second comparison step, the comparison result in the third comparison step, the step size upper limit value, and the step size lower limit value A step size generation step of generating a step size to be used for updating the current tap coefficient based on the current time. 27. A waveform equalization control method for controlling updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, comprising: Estimating the error of the output signal from the signal, generating an error signal, determining the magnitude of the determination error probability of the error estimation for the output signal, generating a determination signal, based on the determination signal, Determining a step size that is a step of updating the tap coefficient, and comprising calculating the tap coefficient update amount based on the error signal, the step size, and data used for updating the tap coefficient. A waveform equalization control method characterized in that: 28. A waveform equalization control method for controlling updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, comprising: an output of the waveform equalizer. Estimating the error of the output signal from the signal, an error estimation step of generating an error signal, based on the error signal, a threshold value and a plurality of step size setting values, the step size is a step size of the update of the tap coefficient A step size determining step of determining; and a coefficient update amount calculating step of calculating a tap coefficient update amount based on the error signal, the step size, and data used for tap coefficient update. Waveform equalization control method. 29. The waveform equalization control method according to claim 28, wherein the plurality of step size setting values are a first step size setting value and a second step size setting value larger than the first step size setting value. A step size setting value, wherein the step size determining step includes: a comparing step of comparing the absolute value of the error signal with the threshold value; and the first step size setting based on a comparison result in the comparing step. A waveform equalization control method, further comprising a selecting step of selecting one of a value and the second step size setting value as the step size. 30. A waveform equalization control method for controlling updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, comprising: an output of the waveform equalizer. An error estimating step of estimating an error of the output signal from the signal, generating an error signal with an error corresponding to a predetermined range of the output signal being 0 among the estimated errors, and tapping based on the error signal. A coefficient update timing control step of generating an update timing signal for controlling a timing of calculating a coefficient update amount at a plurality of symbol intervals; an error signal; a step size that is a step of updating the tap coefficient; and a tap coefficient update. A coefficient update amount calculation method for calculating a tap coefficient update amount at a timing controlled by the update timing signal based on the data and the data. A waveform equalization control method, comprising: 31. The waveform equalization control method according to claim 30, wherein in the coefficient update timing control step, a timing at which a tap coefficient update amount is calculated is equal to or longer than a predetermined symbol interval from a previous timing, and A waveform equalization control method, comprising: generating an update timing signal having a first symbol time when the error signal is not 0. 32. A waveform equalization control method for controlling updating of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, comprising: an output of the waveform equalizer. Estimating an output error from a signal and generating an output error signal; and generating an error signal in which a partial section of the output error signal is reduced at a fixed rate based on the output error signal and the output signal. And a step of calculating a tap coefficient update amount based on the error signal, a step size that is a step of updating the tap coefficient, and data used for updating the tap coefficient. Control method. 33. A waveform equalization control method for controlling update of tap coefficients of a filter included in a waveform equalizer for reducing transmission line distortion of an input signal based on an LMS algorithm, comprising: an output of the waveform equalizer. An output error estimating step of estimating an output error from the signal and generating an output error signal; an error signal generating step of generating an error signal indicating a ratio of an error included in an output signal of the waveform equalizer; Based on the signal, the output signal, and the error signal, a coefficient update error generation step of generating an error signal used for tap coefficient update, and the error signal, the step size of the update of the tap coefficient, A coefficient update amount calculating step of calculating a tap coefficient update amount based on data used for tap coefficient update, a waveform equalization characterized by the above-mentioned. Your way. 34. The waveform equalization control method according to claim 33, wherein in the coefficient update error generation step, it is detected by the error signal that a ratio of an error included in the output signal is smaller than a predetermined ratio. In this case, the same value as the output error signal is generated as the error signal.