# US 9,882,755 B2 · Apparatus for transmitting broadcast signals, apparatus for receiving broadcast signals, method for transmitting broadcast signals and method for receiving broadcast signals

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- Number: US 9,882,755 B2
- Document ID: US9882755B2
- Status: Granted
- Kind: B2
- Application number: 15/398,123
- Filed: 2017-01-04
- Published: 2017-05-25
- Granted: 2018-01-30
- Earliest claimed: 2013-11-25
- Assignees: LG Electronics Inc.
- Applicants: LG Electronics Inc.
- Inventors: Byounggill Kim; Jaehyung Kim; Jaeho Hwang; Woosuk Ko; Sungryong Hong
- Web page: https://patentgrep.com/patent/US9882755B2

## CPC

- H04L 27/2613: {Structure of the reference signals}
- H04L 1/0057: {Block codes (H04L1/0061, H04L1/0064 take precedence)}
- H04L 1/0065: {Serial concatenated codes}
- H04L 1/0071: {Use of interleaving (interleaving per se H03M13/27)}
- H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT}
- H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)}
- H04L 27/26134: {Pilot insertion in the transmitter chain, e.g. pilot overlapping with data, insertion in time or frequency domain}
- H04L 27/26136: {Pilot sequence conveying additional information}
- H04L 27/2628: {Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators (H04L27/2634 takes precedence)}
- H04W 4/06: Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
- H04L 5/0023: {Time-frequency-space}
- H04L 2001/0093: {Point-to-multipoint}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

The present invention provides a method of transmitting broadcast signals. The method includes encoding service data of Physical Layer Pipes (PLPs); bit interleaving the encoded service data; building at least one signal frame including the bit interleaved service data; and modulating data in the at least one signal frame by Orthogonal Frequency Division Multiplexing (OFDM) method; inserting a preamble at a beginning of each of the at least one signal frame after the modulating step; and transmitting the broadcast signals having the modulated data, wherein the preamble includes two OFDM symbols and each of the two OFDM symbols is generated by a sequence multiplication, and wherein each of the two OFDM symbols in the preamble includes information for an emergency alert.

## Claims

### Claim 1

A method of transmitting broadcast signals, the method including:
encoding service data of Physical Layer Pipes (PLPs);
bit interleaving the encoded service data;
building at least one signal frame including the bit interleaved service data; and
modulating data in the at least one signal frame by Orthogonal Frequency Division Multiplexing (OFDM) method;
inserting a preamble at a beginning of each of the at least one signal frame after the modulating step; and
transmitting the broadcast signals having the modulated data,
wherein the preamble includes two OFDM symbols and each of the two OFDM symbols is generated by a sequence multiplication, and
wherein each of the two OFDM symbols in the preamble includes information for an emergency alert.

### Claim 2 (depends on 1)

The method of claim 1, wherein the two OFDM symbols in the preamble include different data in a frequency domain, respectively.

### Claim 3 (depends on 1)

The method of claim 1, wherein each of the two OFDM symbols in the preamble includes different data in a time domain, respectively.

### Claim 4 (depends on 1)

The method of claim 1, wherein values used for the preamble is modulated to output a modulated sequence.

### Claim 5 (depends on 4)

The method of claim 4, wherein the modulated sequence is mapped into active carriers at Inverse Fast Fourier Transform (IFFT) inputs of an OFDM scheme to output a time domain sequence.

### Claim 6

An apparatus for transmitting broadcast signals, the apparatus including:
a processor that
encodes service data of Physical Layer Pipes (PLPs);
bit interleaves the encoded service data;
builds at least one signal frame including the bit interleaved service data; and
modulates data in the at least one signal frame by Orthogonal Frequency Division Multiplexing (OFDM) method;
inserts a preamble at a beginning of each of the at least one signal frame after the data is modulated; and
transmits the broadcast signals having the modulated data,
wherein the preamble includes two OFDM symbols and each of the two OFDM symbols is generated by a sequence multiplication, and
wherein each of the two OFDM symbols in the preamble includes information for an emergency alert.

### Claim 7 (depends on 6)

The apparatus of claim 6, wherein the two OFDM symbols in the preamble include different data in a frequency domain, respectively.

### Claim 8 (depends on 6)

The apparatus of claim 6, wherein each of the two OFDM symbols in the preamble includes different data in a time domain, respectively.

### Claim 9 (depends on 6)

The apparatus of claim 6, wherein values used for the preamble is modulated to output a modulated sequence.

### Claim 10 (depends on 9)

The apparatus of claim 9, wherein the modulated sequence is mapped into active carriers at Inverse Fast Fourier Transform (IFFT) inputs of an OFDM scheme to output a time domain sequence.