Patent ID: 9660850
Date: 2017-05-23
CPC Classifications: H04J,H04L,H04N

Claim:
1. A method for transmitting broadcast signals, the method comprising: encoding service data bits; mapping the encoded service data bits into; frequency interleaving the symbols in a signal frame by applying a different interleaving sequence to data corresponding to every OFDM (Orthogonal Frequency Division Multiplex) symbol, wherein the frequency interleaving includes: generating the main interleaving sequence including a 1-bit toggle bit generating a symbol offset for every OFDM symbol pair; wherein the interleaving sequence is generated based upon the main interleaving sequence and the symbol offset for every OFDM pair, and wherein it is checked whether a memory index for the interleaving sequence is valid, wherein the frequency interleaving for the signal frame is reset when a first signal frame is changed to a second signal frame; modulating the frequency-interleaved symbols by an OFDM scheme; and transmitting the broadcast signals carrying the modulated symbols.