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

• US 8,054,891 B2
• Filed: 12/06/2010
• Issued: 11/08/2011
• Est. Priority Date: 02/10/2006
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Woo Chan, Kim, Byoung Gill, Choi, In Hwan, Kwak, Kook Yeon, Kang, Kyung Won
• Primary Examiner(s): Fan; Chiem M
• Assistant Examiner(s): Hughes; Eboni
• Application Number:
  US12/961,435
• Publication Number:
  US 20110078535A1
• Time in Patent Office: 337 Days
• Field of Search: 375/229, 375/231, 375/232, 37524025-24027, 348607-614, 348723-726, 348/728
• US Class Current: 375/240.27
• CPC Class Codes: H03M 13/2792 Interleaver wherein interleaving is performed jointly with another technique such as puncturing, multiplexing or routing
• CPC Class Codes: H03M 13/2906 using block codes H03M13/2957 takes precedence
• CPC Class Codes: H03M 13/2936 comprising an outer Reed-Solomon code and an inner convolutional code
• CPC Class Codes: H03M 13/6538 ATSC VBS systems
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 25/0212 of impulse response
• CPC Class Codes: H04L 25/0232 by interpolation between sounding signals
• CPC Class Codes: H04L 25/03159 operating in the frequency domain H04L25/03165, H04L25/03178 take precedence
• CPC Class Codes: H04N 19/89 involving methods or arrangements for detection of transmission errors at the decoder
• CPC Class Codes: H04N 19/895 in combination with error concealment
• CPC Class Codes: H04N 21/236 Assembling of a multiplex stream, e.g. transport stream, by combining a video stream with other content or additional data, e.g. inserting a URL [Uniform Resource Locator] into a video stream, multiplexing software data into a video stream; Remultiplexing of multiplex streams; Insertion of stuffing bits into the multiplex stream, e.g. to obtain a constant bit-rate; Assembling of a packetised elementary stream multiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/23614 Multiplexing of additional data and video streams arrangements for simultaneous broadcast of plural pieces of information H04H20/28
• CPC Class Codes: H04N 21/631 Multimode Transmission, e.g. transmitting basic layers and enhancement layers of the content over different transmission paths or transmitting with different error corrections, different keys or with different transmission protocols
• CPC Class Codes: H04N 5/21 Circuitry for suppressing or minimising disturbance, e.g. moiré or halo
• CPC Class Codes: H04N 5/38 Transmitter circuitry for the transmission of television signals according to analogue transmission standards H04N5/14 takes precedence
• CPC Class Codes: H04N 5/40 Modulation circuits
• CPC Class Codes: H04N 5/455 Demodulation-circuits
• CPC Class Codes: H04N 7/12 Systems in which the television signal is transmitted via one channel or a plurality of parallel channels, the bandwidth of each channel being less than the bandwidth of the television signal H04N7/24 takes precedence

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.

Claims

1. A method of processing a digital broadcast signal for transmitting the digital broadcast signal, the method comprising:

Forward Error Correction (FEC) and Cyclic Redundancy Check (CRC) encoding enhanced service data to build at least one Reed-Solomon (RS) frame of the enhanced service data;

encoding the enhanced service data in the at least one built RS frame at a coding rate of at least 1/2 or 1/4 to output symbols;

forming a data group including the encoded enhanced service data, a plurality of known data sequences and place holder bytes for main service data, MPEG headers and RS parity data;

removing the place holder bytes for the main service data and the RS parity data which are included in the data group and replacing the place holder bytes for the MPEG headers with the MPEG headers, and outputting enhanced service data packets;

multiplexing the output enhanced service data packets and main service data packets including main service data; and

interleaving the enhanced service data and the main service data of the multiplexed enhanced and main service data packets in the data group,

wherein the data group, having the interleaved enhanced service data and the interleaved main service data, includes first segments, second segments and third segments, the second segments being positioned between the first and third segments, the first segments having enhanced service data and main service data, the second segments having enhanced service data and the plurality of known data sequences, and the third segments having enhanced service data and main service data,

wherein the enhanced service data in the first, second and third segments are encoded by non-systematic RS encoding, the main service data in the first and third segments are encoded by systematic RS encoding, and at least two of the plurality of known data sequences have different patterns.

2. The method of claim 1, further comprising:

randomizing the main service data in the multiplexed enhanced and main service data packets and bypassing the enhanced service data in the multiplexed enhanced and main service data packets.

3. The method of claim 1, wherein encoding the enhanced service data comprises:

converting data bytes of the enhanced service data included in the at least one built RS frame into data bits; and

encoding the converted data bits at a coding rate of at least 1/2 or 1/4 to output symbols.

4. The method of claim 3, wherein encoding the enhanced service data further comprises:

interleaving the output symbols; and

converting the interleaved symbols into data bytes of the enhanced service data.

5. An apparatus for processing a digital broadcast signal for transmitting the digital broadcast signal, the apparatus comprising:

a Reed-Solomon (RS) frame encoder configured to Forward Error Correction (FEC) and Cyclic Redundancy Check (CRC) encode enhanced service data to build at least one RS frame of the enhanced service data;

a block processor configured to encode the enhanced service data in the at least one built RS frame at a coding rate of at least 1/2 or 1/4 to output symbols;

a group formatter configured to form a data group including the encoded enhanced service data, a plurality of known data sequences and place holder bytes for main service data, MPEG headers, and RS parity data;

a packet formatter configured to remove the place holder bytes for the main service data and the RS parity data which are included in the data group and replace the place holder bytes for the MPEG headers with the MPEG headers, and output enhanced service data packets;

a packet multiplexer configured to multiplex the output enhanced service data packets and main service data packets including main service data; and

a data interleaver configured to interleave the enhanced service data and the main service data of the multiplexed enhanced and main service data packets in the data group,

wherein;

the data group, having the interleaved enhanced service data and the interleaved main service data, includes first segments, second segments, and third segments, the second segments being positioned between the first and third segments, the first segments having enhanced service data and main service data, the second segments having enhanced service data and the plurality of known data sequences and the third segments having enhanced service data and main service data, and

the enhanced service data in the first, second and third segments are encoded by non-systematic RS encoding, the main service data in the first and third segments are encoded by systematic RS encoding, and at least two of the plurality of known data sequences have different patterns.

6. The apparatus of claim 5, further comprising:

a modified data randomizer configured to randomize the main service data in the multiplexed enhanced and main service data packets and bypass the enhanced service data in the multiplexed enhanced and main service data packets.

7. The apparatus of claim 5, wherein the block processor is further configured to convert data bytes of the enhanced service data included in the at least one built RS frame into data bits and encode the converted data bits at a coding rate of at least 1/2 or 1/4 to output symbols.

8. The method of claim 7, wherein the block processor is further configured to interleave the output symbols and convert the interleaved symbols into data bytes of the enhanced service data.