Apparatus for transmitting broadcast signals, apparatus for receiving broadcast signals, method for transmitting broadcast signals and method for receiving broadcast signals
A method and an apparatus for transmitting broadcast signals thereof are disclosed. The apparatus for transmitting broadcast signals comprises an encoder for encoding DP (Data Pipe) data corresponding to each of a plurality of DPs, a mapper for mapping the encoded DP data onto constellations, a time interleaver for time interleaving the mapped DP data at DP level, a frame builder for building at least one signal frame including the time interleaved DP data, a modulator for modulating data in the built at least one signal frame by an OFDM (Orthogonal Frequency Division Multiplex) scheme and a transmitter for transmitting the broadcast signals having the modulated data.
1. A method for transmitting broadcast signals by an apparatus for transmitting broadcast signals, the method comprising:
encoding service data;
mapping the encoded service data to output cells, wherein the cells are included in at least one forward error correction (FEC) block;
time interleaving the mapped service data, wherein the time interleaving includes:
a column-wise writing the at least one FEC block into at least one time interleaving (TI) block,
wherein the at least one TI block includes at least one virtual FEC block,
wherein a number of FEC blocks vary depending on cell rate of the cells included in the at least one FEC block; and
diagonal-wise reading the at least one TI block based on a diagonal-wise reading parameter, wherein cells in the at least one virtual FEC block are skipped during the diagonal-wise reading based on cell position;
building at least one signal frame including the time interleaved service data;
modulating data in the built at least one signal frame by an Orthogonal Frequency Division Multiplex (OFDM) scheme; and
transmitting the broadcast signals having the modulated data.
2. The method of claim 1 , wherein the method further includes:
the diagonal-wise reading is performed by calculating the cell position based on row and column indexes of TI memory, and
wherein slope for the diagonal wise reading is based on the diagonal-wise reading parameter.
3. The method of claim 1 , wherein the at least one TI block includes the at least one virtual FEC block, when a number of columns of a TI block is smaller than a maximum number of columns for the time interleaving.
4. The method of claim 1 , wherein the number of virtual FEC blocks in a TI block is based on a maximum number of columns for the time interleaving.
5. An apparatus for transmitting broadcast signals, the apparatus comprising:
an encoder to encode service data;
a mapper to map the encoded service data to output cells, wherein the cells are included in at least one forward error correction (FEC) block;
a time interleaver to time interleave the mapped service data, wherein the time interleaver performs:
a column-wise writing the at least one FEC block into at least one time interleaving (TI) block,
wherein the at least one TI block includes at least one virtual FEC block,
wherein a number of FEC blocks vary depending on cell rate of the cells included in the at least one FEC block; and
diagonal-wise reading the at least one TI block based on a diagonal-wise reading parameter, wherein cells in the at least one virtual FEC block are skipped during the diagonal-wise reading based on cell position;
a frame builder to build at least one signal frame including the time interleaved service data;
a modulator to modulate data in the built at least one signal frame by an Orthogonal Frequency Division Multiplex (OFDM) scheme; and
a transmitter to transmit the broadcast signals having the modulated data.
6. The apparatus of claim 5 , wherein
the diagonal-wise reading is performed by calculating the cell position based on row and column indexes of TI memory, and
wherein slope for the diagonal wise reading is based on the diagonal-wise reading parameter.
7. The apparatus of claim 5 , wherein the at least one TI block includes the at least one virtual FEC block, when a number of columns of a TI block is smaller than a maximum number of columns for the time interleaving.
8. The apparatus of claim 5 , wherein the number of virtual FEC blocks in a TI block is based on a maximum number of columns for the time interleaving.
9. A method for receiving broadcast signals by an apparatus for receiving broadcast signals, the method comprising:
receiving the broadcast signals;
demodulating the received broadcast signals by an Orthogonal Frequency Division Multiplex (OFDM) scheme;
parsing at least one signal frame from the demodulated broadcast signals to output service data;
time-deinterleaving the service data in the parsed at least one signal frame, wherein the time de-interleaving is an inverse process of a time interleaving, wherein the time interleaving includes:
a column-wise writing at least one FEC block into at least one time interleaving (TI) block,
wherein the at least one TI block includes at least one virtual FEC block,
wherein a number of FEC blocks vary depending on cell rate of cells included in the at least one FEC block; and
diagonal-wise reading the at least one TI block based on a diagonal-wise reading parameter, wherein cells in the at least one virtual FEC block are skipped during the diagonal-wise reading based on cell position;
demapping the time deinterleaved service data; and
decoding the demapped service data.
10. The method of claim 9 , wherein the method further includes:
the diagonal-wise reading is performed by calculating the cell position based on row and column indexes of TI memory, and
wherein slope for the diagonal wise reading is based on the diagonal-wise reading parameter.
11. The method of claim 9 , wherein the at least one TI block includes the at least one virtual FEC block, when a number of columns of a TI block is smaller than a maximum number of columns for the time interleaving.
12. The method of claim 9 , wherein the number of virtual FEC blocks in a TI block is based on a maximum number of columns for the time interleaving.
13. An apparatus for receiving broadcast signals, the apparatus comprising:
a receiver to receive the broadcast signals;
a demodulator to demodulate the received broadcast signals by an Orthogonal Frequency Division Multiplex (OFDM) scheme;
a frame parser to parse at least one signal frame from the demodulated broadcast signals to output service data;
a time deinterleaver to perform time-deinterleaving the service data in the parsed at least one signal frame, wherein the time de-interleaving is an inverse process of a time interleaving, wherein the time interleaving includes:
a column-wise writing at least one FEC block into at least one time interleaving (TI) block,
wherein the at least one TI block includes at least one virtual FEC block,
wherein a number of FEC blocks vary depending on cell rate of cells included in the at least one FEC block; and
diagonal-wise reading the at least one TI block based on a diagonal-wise reading parameter, wherein cells in the at least one virtual FEC block are skipped during the diagonal-wise reading based on cell position;
a demapper to demap the time deinterleaved service data; and
a decoder to decode the demapped service data.
14. The apparatus of claim 13 ,
wherein the diagonal-wise reading is performed by calculating the cell position based on row and column indexes of TI memory, and
wherein slope for the diagonal wise reading is based on the diagonal-wise reading parameter.
15. The apparatus of claim 13 , wherein the at least one TI block includes the at least one virtual FEC block, when a number of columns of a TI block is smaller than a maximum number of columns for the time interleaving.
16. The apparatus of claim 13 , wherein the number of virtual FEC blocks in a TI block is based on a maximum number of columns for the time interleaving.