Digital broadcast receiving device capable of indicating a receiving signal strength or quality
First Claim
1. A digital broadcast receiving device for demodulating and converting a digital broadcasting signal received at a receiving circuit into a video and audio analog signal which is used in the digital broadcasting system that codes both video and audio signals or either one and adds additional data for control and information transmission and an error correction symbol for improving transmission errors, comprising:
- means for measuring an input field strength of the received digital broadcasting signal received at the receiving circuit;
first indicating means for indicating said input field strength;
means for detecting transmission errors of the received digital broadcasting signal;
means for calculating an error rate from the detection results of said detecting means;
means for converting said error rate into a receiving signal quality; and
second indicating means for indicating said receiving signal quality.
1 Assignment
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Accused Products
Abstract
An error detecting/correcting circuit 9 in a digital broadcast receiving device calculates a error rate from the error amount for the amount of input information. A controlling part 15 converts the error rate into the C/N ratio as a receiving signal quality and indicates it on a screen of a TV receiver 5 or other indicator 18. In this method, after digitally demodulating the received digital broadcasting signal, the error rate is obtained by an error detecting part 9 and the error rate is converted into the receiving signal quality for indication. Therefore, compared with the reception performance indication based on the input level such as the AGC voltage, the method is high both in precision and in stability. The receiving signal quality can be detected only while receiving a digital broadcasting signal, so with reference to the converted receiving signal quality in antenna bearing adjustment, a digital broadcasting signal can be surely received without confusing it with an analog broadcasting signal.
128 Citations
13 Claims
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1. A digital broadcast receiving device for demodulating and converting a digital broadcasting signal received at a receiving circuit into a video and audio analog signal which is used in the digital broadcasting system that codes both video and audio signals or either one and adds additional data for control and information transmission and an error correction symbol for improving transmission errors, comprising:
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means for measuring an input field strength of the received digital broadcasting signal received at the receiving circuit; first indicating means for indicating said input field strength; means for detecting transmission errors of the received digital broadcasting signal; means for calculating an error rate from the detection results of said detecting means; means for converting said error rate into a receiving signal quality; and second indicating means for indicating said receiving signal quality. - View Dependent Claims (3, 5, 7)
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2. A digital broadcast receiving device for demodulating and converting a digital broadcasting signal received at a receiving circuit into a video and audio analog signal which is used in the digital broadcasting system that codes both video and audio signals or either one and adds additional data for control and information transmission and an error correction symbol for improving transmission errors, comprising:
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first detecting means for detecting transmission errors of the digital broadcasting signal received at the receiving circuit; means for calculating an error rate from the detection results of said first detecting means; means for converting said error rate into a receiving signal quality; first indicating means for indicating said receiving signal quality; means for generating an AGC voltage according to an input level of said receiving circuit and automatically controlling an output level to be constant; second detecting means for detecting the input level based on the AGC voltage from said AGC means; and second indicating means for indicating the input level detected by said second detecting means. - View Dependent Claims (4, 6, 8, 9, 10)
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11. A digital broadcast receiving device for demodulating and converting a digital broadcasting signal received at a receiving circuit into a video and audio analog signal which is used in the digital broadcasting system that codes both video and audio signals or either one and adds additional data for control and information transmission and an error correction symbol for improving transmission errors, comprising:
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first detecting means for detecting transmission errors of the digital broadcasting signal received at the receiving circuit; first calculating means for calculating an error rate from the detection results of said first detecting means; means for generating an AGC voltage according to the input level of said receiving circuit and automatically controlling an output level to be constant; second detecting means for detecting the input level based on the AGC voltage from said AGC means; second calculating means for calculating a first receiving signal quality based on the error rate in a domain where the error rate can be measured and for calculating a second receiving signal quality based on said input level in a domain where the error rate cannot be measured; and means for indicating the calculated first and second receiving signal qualities. - View Dependent Claims (12)
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13. A digital broadcast receiving device for demodulating a digital broadcasting signal received at a receiving circuit into which is used in the digital broadcasting system that codes both video and audio signals or either one and adds additional data for control and information transmission and an error correction symbol for improving transmission errors, comprising:
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means for measuring an input field strength of the digital broadcasting signal received at the receiving circuit; first indicating means for indicating said input field strength; means for detecting transmission errors of the digital broadcasting signal received at the receiving circuit; means for calculating an error rate from the detection results of said detecting means; means for converting said error rate into a receiving signal quality; and second indicating means for indicating said receiving signal quality.
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Specification