CHANNEL EQUALIZER AND METHOD OF PROCESSING BROADCAST SIGNAL IN DTV RECEIVING SYSTEM
First Claim
1. A method of processing a broadcast signal in a DTV receiving system, the method comprising:
- converting normal data in a broadcast signal into frequency domain data, wherein a known data sequence is periodically repeated in the normal data;
estimating channel impulse response during intervals in which first and second known data sequences located before and after each normal data block in the broadcast signal are received;
calculating an average value of the estimated channel impulse responses;
converting the average value into frequency domain data;
calculating equalization coefficients using the average value in the frequency domain;
compensating channel distortion of each normal data block in the frequency domain by multiplying each normal data block with the equalization coefficients; and
converting the compensated normal data block into time domain data.
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Abstract
A channel equalizer includes a first transformer, an estimator, an average calculator, a second transformer, a coefficient calculator, a compensator, and a third transformer. The first transformer converts normal data into frequency domain data, where a known data sequence is periodically repeated in the normal data. The estimator estimates channel impulse responses (CIR) during known data intervals adjacent to each normal data block. The average calculator calculates an average value of the CIRs. The second transformer converts the average value into frequency domain data. The coefficient calculator calculates equalization coefficients using the average value, and the compensator compensates channel distortion of each normal data block using the coefficients. The third transformer converts the compensated data block into time domain data.
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Citations
34 Claims
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1. A method of processing a broadcast signal in a DTV receiving system, the method comprising:
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converting normal data in a broadcast signal into frequency domain data, wherein a known data sequence is periodically repeated in the normal data;
estimating channel impulse response during intervals in which first and second known data sequences located before and after each normal data block in the broadcast signal are received;
calculating an average value of the estimated channel impulse responses;
converting the average value into frequency domain data;
calculating equalization coefficients using the average value in the frequency domain;
compensating channel distortion of each normal data block in the frequency domain by multiplying each normal data block with the equalization coefficients; and
converting the compensated normal data block into time domain data. - View Dependent Claims (2, 3, 4)
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5. A method of processing a broadcast signal in a DTV receiving system, the method comprising:
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overlapping normal data in a broadcast signal at a predetermined overlap ratio, wherein a known data sequence is periodically repeated in the normal data;
converting the overlapped normal data into frequency domain data;
estimating a channel impulse response using the known data sequence;
converting the estimated channel impulse response into frequency domain data;
calculating equalization coefficients using the estimated channel impulse response in the frequency domain;
compensating channel distortion of the normal data in the frequency domain by multiplying the normal data with the equalization coefficients;
converting the compensated normal data into time domain data; and
saving the compensated normal data in the time domain. - View Dependent Claims (6, 7, 8)
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9. A method of processing a broadcast signal in a DTV receiving system, the method comprising:
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overlapping normal data in a broadcast signal at a predetermined overlap ratio, wherein a known data sequence is periodically repeated in the normal data;
converting the overlapped normal data into frequency domain data;
estimating a first channel impulse response during a known data interval;
estimating a second channel impulse response during a normal data interval by interpolating the first channel impulse response;
converting the estimated second channel impulse response into frequency domain data;
calculating equalization coefficients using the second channel impulse response in the frequency domain;
compensating channel distortion of the normal data in the frequency domain by multiplying the normal data with the equalization coefficients;
converting the compensated normal data into time domain data; and
saving the compensated normal data in the time domain. - View Dependent Claims (10, 11, 12)
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13. A method of processing a broadcast signal in a DTV receiving system, the method comprising:
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overlapping normal data in a broadcast signal at a predetermined overlap ratio, wherein a known data sequence is periodically repeated in the normal data;
converting the overlapped normal data into frequency domain data;
compensating channel distortion of the normal data in the frequency domain by multiplying the normal data with equalization coefficients;
converting the compensated normal data into time domain data;
saving the compensated normal data in the time domain;
calculating an error of the saved normal data using a decision value of the saved normal data and the known data sequence;
padding zeros into the error according to the overlap ratio;
converting the zero-padded error into frequency domain data; and
updating the equalization coefficients based on the zero-padded error in the frequency domain. - View Dependent Claims (14, 15, 16, 17)
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18. A channel equalizer for use in a DTV receiving system, the channel equalizer comprising:
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a first transformer for converting normal data in a broadcast signal into frequency domain data, wherein a known data sequence is periodically repeated in the normal data;
an estimator for estimating channel impulse responses during intervals in which first and second known data sequences located before and after each normal data block in the broadcast signal are received;
an average calculator for calculating an average value of the estimated channel impulse responses;
a second transformer for converting the average value into frequency domain data;
a coefficient calculator for calculating equalization coefficients using the average value in the frequency domain;
a compensator for compensating channel distortion of each normal data block in the frequency domain by multiplying each normal data block with the equalization coefficients; and
a third transformer for converting the compensated normal data block into time domain data. - View Dependent Claims (19, 20, 21)
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22. A channel equalizer for use in a DTV receiving system, the channel equalizer comprising:
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an overlap unit for overlapping normal data in a broadcast signal at a predetermined overlap ratio, wherein a known data sequence is periodically repeated in the normal data;
a first transformer for converting the overlapped normal data into frequency domain data;
an estimator estimating a channel impulse response using the known data sequence;
a second transformer for converting the estimated channel impulse response into frequency domain data;
a calculator for calculating equalization coefficients using the estimated channel impulse response in the frequency domain;
a compensator for compensating channel distortion of the normal data in the frequency domain by multiplying the normal data with the equalization coefficients;
a third transformer for converting the compensated normal data into time domain data; and
a save unit for saving the compensated normal data in the time domain. - View Dependent Claims (23, 24, 25)
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26. A channel equalizer for use in a DTV receiving system, the channel equalizer comprising:
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an overlap unit for overlapping normal data in a broadcast signal at a predetermined overlap ratio, wherein a known data sequence is periodically repeated in the normal data;
a first transformer for converting the overlapped normal data into frequency domain data;
an estimator estimating a first channel impulse response during a known data interval;
an interpolator estimating a second channel impulse response during a normal data interval by interpolating the first channel impulse response;
a second transformer for converting the estimated second channel impulse response into frequency domain data;
a calculator for calculating equalization coefficients using the second channel impulse response in the frequency domain;
a compensator for compensating channel distortion of the normal data in the frequency domain by multiplying the normal data with the equalization coefficients;
a third transformer for converting the compensated normal data into time domain data; and
a save unit for saving the compensated normal data in the time domain. - View Dependent Claims (27, 28, 29)
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30. A channel equalizer for use in a DTV receiving system, the channel equalizer comprising:
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an overlap unit for overlapping normal data in a broadcast signal at a predetermined overlap ratio, wherein a known data sequence is periodically repeated in the normal data;
a first transformer for converting the overlapped normal data into frequency domain data;
a compensator for compensating channel distortion of the normal data in the frequency domain by multiplying the normal data with equalization coefficients;
a second transformer for converting the compensated normal data into time domain data;
a save unit for saving the compensated normal data in the time domain;
an error calculator for calculating an error of the saved normal data using a decision value of the saved normal data and the known data sequence;
a padding unit for padding zeros into the error according to the overlap ratio;
a third transformer for converting the zero-padded error into frequency domain data; and
a coefficient update unit for updating the equalization coefficients based on the zero-padded error in the frequency domain. - View Dependent Claims (31, 32, 33, 34)
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Specification