Patent ID: 9628973
Date: 2017-04-18
CPC Classifications: H03M,H04B,H04L,H04W,Y02D

Claim:
1. A method of providing an emergency alert via broadcast signal transmission, the method including: encoding data of PLPs (Physical Layer Pipes) with LDPC (Low Density Parity Check) codes; bit interleaving the LDPC encoded data of the PLPs; mapping the bit interleaved data onto constellations; time interleaving the mapped data; building at least one signal frame by mapping the time interleaved data; and modulating data in the built signal frame by OFDM (Orthogonal Frequency Division Multiplexing) method, combining a first sequence and a second sequence for generating a preamble symbol; inserting the generated preamble symbol in the at least one signal frame at a beginning of each of the at least one signal frame after the OFDM modulating data in the at least one signal frame; and transmitting broadcast signals having the at least one signal frame, wherein wake up information is transmitted in the preamble symbol.