Channel equalizer and method of processing broadcast signal in DTV receiving system

A method of processing a broadcast signal in a DTV receiving system, the method comprising:

• receiving in a receiver the broadcast signal including a data group having first segments, second segments and third segments, the second segments being positioned between the first and third segments, the first segments having mobile data and main data, the second segments having mobile data and known data sequences and the third segments having mobile data and main data, wherein the mobile data in the first, second and third segments are encoded by RS-CRC (Reed Solomon-cyclic redundancy check) encoding and non-systematic RS encoding, the main data in the first and third segments are encoded by systematic RS encoding and at least two of the known data sequences have different patterns;
• overlapping the mobile data of the broadcast signal at a predetermined overlap ratio;
• converting the overlapped mobile data into frequency domain data;
• estimating a channel impulse response using the known data sequences;
• 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 mobile data in the frequency domain by multiplying the mobile data with the equalization coefficients;
• converting the compensated mobile data into time domain data;
• and
• saving the compensated mobile data in the time domain.

A method of processing a broadcast signal in a DTV receiving system, the method comprising:

• receiving in a receiver the broadcast signal including a data group having first segments, second segments and third segments, the second segments being positioned between the first and third segments, the first segments having mobile data and main data, the second segments having mobile data and known data sequences and the third segments having mobile data and main data, wherein the mobile data in the first, second and third segments are encoded by RS-CRC (Reed Solomon-cyclic redundancy check) encoding and non-systematic RS encoding, the main data in the first and third segments are encoded by systematic RS encoding and at least two of the known data sequences have different patterns;
• overlapping the mobile data of the broadcast signal at a predetermined overlap ratio;
• converting the overlapped mobile data into frequency domain data;
• estimating a first channel impulse response during a known data interval;
• estimating a second channel impulse response during a mobile 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 mobile data in the frequency domain by multiplying the mobile data with the equalization coefficients;
• converting the compensated mobile data into time domain data;
• and
• saving the compensated mobile data in the time domain.

A method of processing a broadcast signal in a DTV receiving system, the method comprising:

• receiving in a receiver the broadcast signal including a data group having first segments, second segments and third segments, the second segments being positioned between the first and third segments, the first segments having mobile data and main data, the second segments having mobile data and known data sequences and the third segments having mobile data and main data, wherein the mobile data in the first, second and third segments are encoded by RS-CRC (Reed Solomon-cyclic redundancy check) encoding and non-systematic RS encoding, the main data in the first and third segments are encoded by systematic RS encoding and at least two of the known data sequences have different patterns;
• overlapping the mobile data of the broadcast signal at a predetermined overlap ratio;
• converting the overlapped mobile data into frequency domain data;
• compensating channel distortion of the mobile data in the frequency domain by multiplying the mobile data with equalization coefficients;
• converting the compensated mobile data into time domain data;
• saving the compensated mobile data in the time domain;
• calculating an error of the saved mobile data using a decision value of the saved mobile data and the known data sequences;
• 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.

A DTV receiving system comprising:

• a receiver receiving a broadcast signal including a data group having first segments, second segments and third segments, the second segments being positioned between the first and third segments, the first segments having mobile data and main data, the second segments having mobile data and known data sequences and the third segments having mobile data and main data, wherein the mobile data in the first, second and third segments are encoded by RS-CRC (Reed Solomon-cyclic redundancy check) encoding and non-systematic RS encoding, the main data in the first and third segments are encoded by systematic RS encoding and at least two of the known data sequences have different patterns;
• a first transformer for converting the mobile data of the broadcast signal into frequency domain data;
• an estimator for estimating channel impulse responses during intervals in which first and second known data sequences located before and after each mobile 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 of the estimated channel impulse responses into frequency domain data;
• a coefficient calculator for calculating equalization coefficients using the average value of the estimated channel impulse responses in the frequency domain;
• a compensator for compensating channel distortion of each mobile data block in the frequency domain by multiplying each mobile data block with the equalization coefficients;
• and
• a third transformer for converting the compensated mobile data block into time domain data.

A DTV receiving system comprising:

• a receiver receiving a broadcast signal including a data group having first segments, second segments and third segments, the second segments being positioned between the first and third segments, the first segments having mobile data and main data, the second segments having mobile data and known data sequences and the third segments having mobile data and main data, wherein the mobile data in the first, second and third segments are encoded by RS-CRC (Reed Solomon-cyclic redundancy check) encoding and non-systematic RS encoding, the main data in the first and third segments are encoded by systematic RS encoding and at least two of the known data sequences have different patterns;
• an overlap unit for overlapping the mobile data of the broadcast signal at a predetermined overlap ratio;
• a first transformer for converting the overlapped mobile 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 mobile data in the frequency domain by multiplying the mobile data with the equalization coefficients;
• a third transformer for converting the compensated mobile data into time domain data;
• and
• a save unit for saving the compensated mobile data in the time domain.

A DTV receiving system comprising:

• a receiver receiving a broadcast signal including a data group having first segments, second segments and third segments, the second segments being positioned between the first and third segments, the first segments having mobile data and main data, the second segments having mobile data and known data sequences and the third segments having mobile data and main data, wherein the mobile data in the first, second and third segments are encoded by RS-CRC (Reed Solomon-cyclic redundancy check) encoding and non-systematic RS encoding, the main data in the first and third segments are encoded by systematic RS encoding and at least two of the known data sequences have different patterns;
• an overlap unit for overlapping the mobile data of the broadcast signal at a predetermined overlap ratio;
• a first transformer for converting the overlapped mobile 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 mobile 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 mobile data in the frequency domain by multiplying the mobile data with the equalization coefficients;
• a third transformer for converting the compensated mobile data into time domain data;
• and
• a save unit for saving the compensated mobile data in the time domain.

A channel equalizer for use in a DTV receiving system, the channel equalizer comprising:

• a receiver receiving a broadcast signal including a data group having first segments, second segments and third segments, the second segments being positioned between the first and third segments, the first segments having mobile data and main data, the second segments having mobile data and known data sequences and the third segments having mobile data and main data, wherein the mobile data in the first, second and third segments are encoded by RS-CRC (Reed Solomon-cyclic redundancy check) encoding and non-systematic RS encoding, the main data in the first and third segments are encoded by systematic RS encoding and at least two of the known data sequences have different patterns;
• an overlap unit for overlapping the mobile data of the broadcast signal at a predetermined overlap ratio;
• a first transformer for converting the overlapped mobile data into frequency domain data;
• a compensator for compensating channel distortion of the mobile data in the frequency domain by multiplying the mobile data with equalization coefficients;
• a second transformer for converting the compensated mobile data into time domain data;
• a save unit for saving the compensated mobile data in the time domain;
• an error calculator for calculating an error of the saved mobile data using a decision value of the saved mobile data and the known data sequences;
• 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.

A method for processing a digital broadcasting signal in a receiver, the method comprising:

• receiving the digital broadcasting signal having including a data group having first segments, second segments and third segments, the second segments being positioned between the first and third segments, the first segments having mobile data and main data, the second segments having mobile data and known data sequences and the third segments having mobile data and main data, wherein the mobile data in the first, second and third segments are encoded by RS-CRC (Reed Solomon-cyclic redundancy check) encoding and non-systematic RS encoding, the main data in the first and third segments are encoded by systematic RS encoding and at least two of the known data sequences have different patterns;
• equalizing the digital broadcasting signal in accordance with the received known data sequences by estimating a channel impulse response (CIR) by using the known data sequences;
• and
• decoding the equalized broadcasting signal.

An apparatus for processing a digital broadcasting signal, the apparatus comprising:

• a receiving unit for receiving the digital broadcasting signal including first 207-byte segments, second 207-byte segments and third 207-byte segments, the first 207-byte segments having mobile data and main data, the second 207-byte segments being positioned between the first and third 207-byte segments, the second 207-byte segments having mobile data and known data sequences and the third 207-byte segments having mobile data and main data, wherein the mobile data in the first, second and third 207-byte segments are encoded by RS-CRC (Reed Solomon-cyclic redundancy check) encoding and non-systematic RS encoding, the main data in the first and third segments are encoded by systematic RS encoding and at least two of the known data sequences have different patterns;
• an equalizing unit for equalizing the digital broadcasting signal in accordance with the received known data sequences by estimating a channel impulse response (CIR) by using the known data sequences;
• and
• a decoding unit for decoding the equalized broadcasting signal.