Signal multiplexing device and signal multiplexing method using layered division multiplexing
An apparatus and method for multiplexing signals using layered division multiplexing are disclosed. A signal multiplexing apparatus according to an embodiment of the present invention includes a combiner configured to combine a core layer signal and an enhanced layer signal at different power levels, and a time interleaver configured to perform interleaving applied to both the core layer signal and the enhanced layer signal.
1. A signal demultiplexer, comprising:
a time deinterleaver configured to perform time deinterleaving on a received signal corresponding to a multiplexed signal;
a core layer BICM decoder configured to restore core layer data of the multiplexed signal;
an enhanced layer symbol extractor configured to extract enhanced layer symbols by performing cancellation corresponding to the core layer data; and
an enhanced layer BICM decoder configured to restore enhanced layer data corresponding to the enhanced layer symbols,
wherein the multiplexed signal corresponds to a combination of a core layer signal and a power-reduced enhanced layer signal,
wherein the power-reduced enhanced layer signal is generated corresponding to a scaling factor by an injection level controller of a transmitter and the power of the combination of the core layer signal and the power-reduced enhanced layer signal is reduced corresponding to a normalizing factor in the transmitter,
wherein the scaling factor decreases as a power reduction corresponding to the power-reduced enhanced layer signal becomes larger, and the normalizing factor increases as the power reduction becomes larger, and
wherein the injection level controller changes an injection level with one of predetermined step sizes, the step sizes including 0.5 dB.
2. The signal demultiplexer of claim 1 , wherein the core layer BICM decoder and the enhanced layer BICM decoder performs operation after the time deinterleaving which is shared for both a core layer and an enhanced layer.
3. A signal demultiplexer, comprising:
a time deinterleaver configured to perform time deinterleaving on a received signal corresponding to a multiplexed signal;
a core layer BICM decoder configured to restore core layer data of the multiplexed signal;
an enhanced layer symbol extractor configured to extract enhanced layer symbols by performing cancellation corresponding to the core layer data;
a de-injection level controller configured to increase the power of the enhanced layer symbols by a level corresponding to a power reduction by an injection level controller of a transmitter; and
an enhanced layer BICM decoder configured to restore enhanced layer data corresponding to the enhanced layer symbols.
4. A signal demultiplexer, comprising:
a time deinterleaver configured to perform time deinterleaving on a received signal corresponding to a multiplexed signal;
a de-normalizer configured to increase the power of an input signal by a level corresponding to a power reduction by a power normalizer of a transmitter to generate a power-adjusted signal;
a core layer BICM decoder configured to restore core layer data of the multiplexed signal;
an enhanced layer symbol extractor configured to extract enhanced layer symbols by performing cancellation corresponding to the core layer data; and
an enhanced layer BICM decoder configured to restore enhanced layer data corresponding to the enhanced layer symbols, and
wherein the power normalizer corresponds to a normalizing factor, and reduces the power of the multiplexed signal by an amount by which the power has been increased by a combiner of the transmitter.
5. A signal demultiplexing method, comprising:
performing time deinterleaving on a received signal corresponding to a multiplexed signal;
restoring, by a core layer BICM decoder, core layer data of the multiplexed signal;
extracting enhanced layer symbols by performing cancellation corresponding to the core layer data; and
restoring, by an enhanced layer BICM decoder, enhanced layer data corresponding to the enhanced layer symbols,
wherein the multiplexed signal corresponds to a combination of a core layer signal and a power-reduced enhanced layer signal,
wherein the power-reduced enhanced layer signal is generated corresponding to a scaling factor by an injection level controller of a transmitter and the power of the combination of the core layer signal and the power-reduced enhanced layer signal is reduced corresponding to a normalizing factor in the transmitter,
wherein the scaling factor decreases as a power reduction corresponding to the power-reduced enhanced layer signal becomes larger, and the normalizing factor increases as the power reduction becomes larger, and
wherein the injection level controller changes an injection level with one of predetermined step sizes, the step sizes including 0.5 dB.