DIGITAL BROADCASTING SYSTEM AND METHOD OF PROCESSING DATA

• US 20100269013A1
• Filed: 02/02/2010
• Published: 10/21/2010
• Est. Priority Date: 07/04/2007
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Byoung Gill, Lee, Hyoung Gon, Choi, In Hwan, Mun, Chul Kyu, Song, Won Gyu, Kwak, Kook Yeon, Kim, Jin Woo
• Granted Patent: US 8,433,973 B2
• Time in Patent Office: Days
• US Class Current: 714/755
• CPC Class Codes: H04H 20/30 by a single channel
• CPC Class Codes: H04H 20/57 for mobile receivers
• CPC Class Codes: H04H 20/95 characterised by a specific format, e.g. an encoded audio stream
• CPC Class Codes: H04H 40/27 specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04N 21/23608 Remultiplexing multiplex streams, e.g. involving modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/2385 Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/41407 embedded in a portable device, e.g. video client on a mobile phone, PDA, laptop constructional details of equipment or arrangements specially adapted for portable computer application G06F1/1626; arrangements specially adapted for mobile receivers in broadcast systems H04H20/57
• CPC Class Codes: H04N 21/4347 Demultiplexing of several video streams
• CPC Class Codes: H04N 21/4348 Demultiplexing of additional data and video streams
• CPC Class Codes: H04N 21/4381 Recovering the multiplex stream from a specific network, e.g. recovering MPEG packets from ATM cells transmission of MPEG streams over ATM H04L12/5601
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/4383 Accessing a communication channel
• CPC Class Codes: H04N 21/6433 Digital Storage Media - Command and Control Protocol [DSM-CC]

Abstract

A digital receiving system, and a method of processing data are disclosed. The digital receiving system includes a receiving unit, a known sequence detector, and a channel equalizer. The receiving unit receives a broadcast signal including mobile service data and main service data. The known sequence detector detects known data linearly inserted in a data group. The channel equalizer performs channel-equalizing on the received mobile service data using the detected known data.

Claims

1. A receiving system, comprising:

a tuner for receiving a broadcast signal including mobile service data and a plurality of known data sequences;

a demodulator for demodulating the broadcast signal;

an equalizer for estimating channel impulse responses (CIRs), by adopting a least mean square (LMS) method so as to update coefficients by shifting a pre-determined filtering window in symbol units, and compensating channel distortion in the demodulated broadcast signal based upon the estimated CIRs;

an inner decoder for inner decoding the channel-equalized broadcast signal; and

an outer decoder for outer decoding the inner-decoded broadcast signal.

2. The receiving system of claim 1, wherein the equalizer matches a position of a main tab within the filtering window to a first symbol of known data that are being received, and then calculates errors and performs coefficients update by shifting the filtering window from n=0 to n=N−

1 (wherein N represents a length of a known data sequence).

3. The receiving system of claim 2, wherein the process of calculating errors and performing coefficients update by shifting the filtering window from n=0 to n=N−

1 is repeated (or iterated) for a predetermined number of iterations.

4. The receiving system of claim 1, wherein the equalizer matches a channel center point within the filtering window to a first symbol of known data that are being received, and then calculates errors and performs coefficients update by shifting the filtering window from n=s to n=N−

1+s, and

wherein N represents a length of a known data sequence, wherein the channel center point corresponds mid-point value between a position of a pre-tab chronologically occurring for the first time and a position of a post-tab chronologically occurring last, and wherein s represents a value subtracting a position of a main tab from the channel center point.

5. The receiving system of claim 4, wherein the process of calculating errors and performing coefficients update by shifting the filtering window from n=s to n=N−

1+s is repeated (or iterated) for a predetermined number of iterations.

6. The receiving system of claim 1, wherein the equalizer matches a position of a pre-tab chronologically occurring for the first time within the filtering window to a first symbol of known data that are being received, and then calculates errors and performs coefficients update by shifting the filtering window from n=s+d to n=N−

1+s−

d, and

wherein N represents a length of a known data sequence, wherein a channel center point corresponds mid-point value between a position of a pre-tab chronologically occurring for the first time and a position of a post-tab chronologically occurring last, wherein s represents a value subtracting a position of a main tab from the channel center point, and wherein d indicates a distance between the channel center point and the pre-tab or the post-tab.

7. The receiving system of claim 6, wherein the process of calculating errors and performing coefficients update by shifting the filtering window from n=s+d to n=N−

1+s−

d is repeated (or iterated) for a predetermined number of iterations.

8. A method of processing broadcast data in a receiving system, the method comprising:

receiving a broadcast signal including mobile service data and a plurality of known data sequences;

demodulating the broadcast signal;

estimating channel impulse responses (CIRs), by adopting a least mean square (LMS) method so as to update coefficients by shifting a pre-determined filtering window in symbol units, and compensating channel distortion in the demodulated broadcast signal based upon the estimated CIRs;

inner decoding the channel-equalized broadcast signal; and

outer decoding the inner-decoded broadcast signal.

9. The method of claim 8, wherein estimating channel impulse responses (CIRs) matches a position of a main tab within the filtering window to a first symbol of known data that are being received, and then calculates errors and performs coefficients update by shifting the filtering window from n=0 to n=N−

1 (wherein N represents a length of a known data sequence).

10. The method of claim 9, wherein the process of calculating errors and performing coefficients update by shifting the filtering window from n=0 to n=N−

1 is repeated (or iterated) for a predetermined number of iterations.

11. The method of claim 8, wherein estimating channel impulse responses (CIRs) matches a channel center point within the filtering window to a first symbol of known data that are being received, and then calculates errors and performs coefficients update by shifting the filtering window from n=s to n=N−

1+s, and

wherein N represents a length of a known data sequence, wherein the channel center point corresponds mid-point value between a position of a pre-tab chronologically occurring for the first time and a position of a post-tab chronologically occurring last, and wherein s represents a value subtracting a position of a main tab from the channel center point.

12. The method of claim 11, wherein the process of calculating errors and performing coefficients update by shifting the filtering window from n=s to n=N−

1+s is repeated (or iterated) for a predetermined number of iterations.

13. The method of claim 8, wherein estimating channel impulse responses (CIRs) matches a position of a pre-tab chronologically occurring for the first time within the filtering window to a first symbol of known data that are being received, and then calculates errors and performs coefficients update by shifting the filtering window from n=s+d to n=N−

1+s−

d, and

wherein N represents a length of a known data sequence, wherein a channel center point corresponds mid-point value between a position of a pre-tab chronologically occurring for the first time and a position of a post-tab chronologically occurring last, wherein s represents a value subtracting a position of a main tab from the channel center point, and wherein d indicates a distance between the channel center point and the pre-tab or the post-tab.

14. The method of claim 13, wherein the process of calculating errors and performing coefficients update by shifting the filtering window from n=s+d to n=N−

1+s−

d is repeated (or iterated) for a predetermined number of iterations.