JPH11331129A - Data receiver using majority logic decoding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably perform error correction, even if a radio wave state or line condition is changed at a data receiver for receiving encoded data. SOLUTION: This data receiver is provided with a means 1 for correcting the error of received data while using a majority logic decoding system, a means 2 for calculating the success rate of error correction, based on the error corrected result and a means 3 for resetting the threshold of majority in the majority logic decoding system and using it for the means 1 to settle the success rate within a target range, when the calculated error correction success rate lies outside of the target range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data receiving apparatus for broadcasting and communication, and more particularly to a data receiving apparatus having an error correction decoding function for encoded received data and a data receiving method.

[0002]

2. Description of the Related Art In a data receiver for broadcasting or communication using encoded data, an error correction decoding process is performed on the received data. The most commonly used decoding method for such an error correction code is a majority logic decoding method. This code which can be decoded by majority logic is generally often configured as a cyclic code. For example, in teletext in Japan, a shortened difference set cyclic (272, 170) code is used.

The error correction capability of a decoding circuit using such a majority logic changes according to the majority threshold. In general, increasing this threshold value lowers the correction capability. If the value is reduced, the correction capability is increased, but there is a possibility that correct data is erroneously corrected.

In broadcasting and data communication, the probability of occurrence of a code error varies depending on the radio wave condition and line conditions. However, in a conventional receiving apparatus, the threshold for majority decision is fixed, and it is not possible to change the error correction capability. However, there is a problem that it is not possible to cope with changes in the radio wave condition and line conditions.

[0005] The present invention provides a data receiving apparatus capable of performing stable error correction by changing a majority decision threshold value in a data receiving apparatus that receives coded data, even if the radio wave condition or the line condition changes. The purpose is to provide.

[0006]

FIG. 1 is a block diagram showing the principle configuration of the present invention. FIG. 1 is a block diagram showing a principle configuration of a data receiving apparatus having an error correction decoding function for encoded received data and using a majority logic decoding method.

In FIG. 1, an error correction means 1 performs error correction on received data encoded using a majority logic decoding method. Further, the error correction success rate calculating means 2 calculates the error correction success rate based on the error correction result by the error correction means 1.

When the error correction success rate calculated by the error correction success rate calculation means 2 is out of a predetermined target range, for example, 75% to 85%,
The threshold value in the majority decision decoding method is reset so that the error correction success rate falls within the target range, and the reset value is used by the error correction means 1.

In the data receiving apparatus of the present invention, a target range of the error correction success rate, for example, a range of 75% to 85% is set in advance. Then, error correction for the received data is executed using a majority logic decoding method, and a success rate of error correction is calculated based on the result of the error correction. The error correction for the received data is performed on the received data for a predetermined time, for example, and the result is recorded. Then, the error correction and the recording of the correction result for the received data are repeated, for example, a plurality of times, and the success rate of the error correction is calculated based on the plurality of recording results.

When the calculated error correction success rate is out of the above-mentioned target range, for example, 75% to 85%, the majority decision threshold is corrected in a direction so that the error correction success rate falls within the target range. , The above-described processing after error correction on the received data is repeated. When the calculated error correction success rate is within the target range, the threshold is not corrected, and the processing after the error correction on the received data is repeated.

As described above, according to the present invention, the error correction capability can be changed by setting the threshold based on the calculation result of the error correction success rate.

[0012]

FIG. 2 shows a configuration example of a broadcasting system in which the data receiving apparatus of the present invention is used. In the figure, the system comprises a broadcast antenna 6 for transmitting FM radio waves and a visible radio 7 for receiving FM radio waves.

FIG. 3 is a block diagram showing the configuration of a data receiving apparatus corresponding to the visible radio shown in FIG. In the figure, the function of the visible radio itself is omitted. In FIG. 3, the data receiving apparatus includes a receiving unit 10 for receiving FM teletext, a decoder 11 for extracting characters from text-multiplexed data, an error correcting unit 12 for performing error correction on an output of the decoder 11, and an error correcting unit. A recording unit 13 for recording an error correction result by the unit 12, a setting unit 15 for setting a target value of an error correction success rate, a threshold setting unit 16 for setting a majority decision threshold, an error correction unit 12, a recording unit 13, and The control unit 17 controls the threshold setting unit 16.

In FIG. 3, for example, the target value of the error correction success rate is set to 80% by the setting unit 15. Since it is difficult for the actual success rate to exactly match 80%, it is possible to set the target range of the success rate, for example, from 75% to 85%. The FM character multiplexed broadcast is received by the receiving unit 10 and the data is transmitted to the decoder unit 11.
And character information is extracted. Error correction is performed on the extracted character data by the error correction unit 12, and the result is recorded in the recording unit 13.

For example, error correction of the next character data is performed at certain time intervals, and the result is recorded in the recording unit 13 one after another. This is repeated, for example, 100 times, and the error correction success rate is calculated based on the error correction result.

If the success rate is smaller than the target value, for example, 60%, the threshold is set to a smaller value in order to increase the success rate. Thereafter, the error correction and the calculation of the success rate are similarly performed. When the success rate becomes 90%, for example, the threshold value is corrected by the threshold value setting unit 16 to a large value. As a result, the success rate of the subsequent error correction becomes a value close to 80%, for example, a value such as 82%, which falls within the target range.

FIG. 4 is a flowchart of an error correction process according to the present invention. When the process is started in FIG.
First, in step S1, the target range of the error correction success rate is set by the setting unit 15, and in step S2, the threshold setting unit 16 is set.
Sets the majority decision threshold.

In step S3, the error correction for the received data is performed by the error correction unit 12, and
In step S5, the result is recorded in the recording unit 13, and in step S5, for example, at certain time intervals, the error correction in step S3 and the recording of the result in step S4 are performed a predetermined number of times, for example,
The control unit 17 determines whether or not the operation has been performed 100 times,
If not, the processing from step S3 is repeated.

If it is determined in step S5 that the predetermined number of times has been reached, the success rate of error correction is calculated by the control unit 17 in step S6, and the success rate of the calculation result is calculated by the control unit 17 in step S7. Is within the target range set in step S1. If it is out of the target range, the threshold setting unit 16 resets the threshold in step S8, and then the processing in step S3 and subsequent steps is repeated.
Step S3 and the subsequent steps are repeated without performing the above processing.

In the above, each time the success rate of error correction is calculated, it is determined whether or not the success rate is within the target range. If the success rate is outside the target range, the threshold is reset immediately. However, as a different embodiment of the present invention, if the success rate is relatively close to the target range even if the success rate is outside the target range, the value of the success rate is calculated several times continuously. It is also possible to change the threshold value only in this case.

Such an embodiment will be described with reference to FIGS. FIG. 5 is an explanatory diagram of the continuous number of success rates for resetting the threshold value. In the figure, the target range in which the threshold value is not changed is 90 to 93%, and a range close to this target range, for example, in the case of 86%, the value of 85 to 90% is calculated five consecutive times. The threshold value is changed, that is, the setting value is reduced. When the success rate is 80% or less or 97% or more, if such a value is calculated once, the threshold is reset, that is, the set value is changed. Here, the setting range of the threshold value, that is, the range of the setting value is 1 to 6.

FIG. 6 is a flowchart of the data error correction processing corresponding to FIG. This figure shows a 83-85% success rate
Is shown as an example. In FIG. 5, in step S10, a value of the number of consecutive times is set corresponding to the success rate, for example, as shown in FIG. 5, and in step S11, for example, "8" is set as an initial value of the threshold. Then, in step S12, the data is received, and in step S1
In step S3, a correction process is performed, and in step S14, a success rate is calculated.

The calculated success rate is, for example, 83% to 85%.
%, 83-85% in step S15.
Is cleared, the counter of step S16 is cleared.
Then, the value of the continuous number counter is incremented, and it is determined in step S17 whether the continuous number has reached three times.

If the number of consecutive times has reached three, the threshold value is changed to a small value in step S18, and step S1 is executed.
After the value of the continuous number counter is cleared in step 9, the processing after step S12 is repeated. If it is determined in step S17 that the number of times has not reached three consecutive times, the processing from step S12 is immediately repeated.

In the above description, the error correction for data and the recording of the result are repeated at certain time intervals. However, it is of course possible to repeat this for every certain number of bits.

[0026]

As described above, according to the present invention, the threshold is set according to the success rate of error correction.
This enables stable data error correction even when the radio wave condition or the line condition changes during data reception, and is particularly effective for mobile receivers and the like in which the radio wave condition is liable to change.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the principle configuration of the present invention.

FIG. 2 is a diagram illustrating a configuration example of a broadcasting system in which the data receiving device of the present invention is used.

FIG. 3 is a block diagram showing a configuration of a data receiving device of the present invention.

FIG. 4 is a flowchart of a data error correction process according to the present invention.

FIG. 5 is a diagram illustrating the number of consecutive error correction success rates at which the threshold must be reset.

6 is a flowchart of a data error correction process corresponding to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Error correction means 2 Error correction success rate calculation means 3 Threshold resetting means 6 Broadcast antenna 7 Visible radio 12 Error correction unit 13 Recording unit 15 Setting unit 16 Threshold setting unit 17 Control unit

Claims (3)

[Claims] 1. A data receiving apparatus having an error correction decoding function for coded reception data, comprising: an error correction unit for performing error correction on the reception data by using a majority logic decoding method; Error correction success rate calculating means for calculating the error correction success rate; and a direction for setting the error correction success rate within the target range when the calculated error correction success rate is outside a predetermined target range. A threshold value resetting means for setting a majority decision threshold value in the majority logic decoding method and using the set value for the error correction means. A data receiving apparatus using a majority logic decoding method. 2. A method for receiving encoded data using an error correction decoding function, comprising: setting a target range of an error correction success rate in advance, performing error correction on received data using a majority logic decoding method, Calculating a success rate of error correction based on the result of the above, when the calculated error correction success rate is outside the target range, the threshold of majority decision in a direction such that the error correction success rate falls within the target range. A data receiving method using a majority logic decoding method, comprising resetting and repeating the process of performing error correction on received data using the majority logic decoding method. 3. A data receiving apparatus having an error correction decoding function for coded reception data, comprising: an error correction means for performing error correction on the reception data by using a majority logic decoding method; An error correction success rate calculating means for calculating a success rate of error correction; and the calculated error correction success rate is a predetermined range outside the predetermined target range continuously for a predetermined number of times. When it is within the range, a threshold value for majority decision in the majority logic decoding system is set in a direction such that the error correction success rate falls within a target range, and a threshold value for causing the error correction means to use the set value is set. A data receiving apparatus using a majority logic decoding method, comprising: resetting means.