Apparatus and method for reducing peak to average power ratio in a signal
View Patent ↗Methods and apparatuses for processing a signal that is transmitted with a reduced peak to average power ratio are described. The processing includes applying ( 1650 ) a first type of symbol constellation extension projection to at least one symbol in the constellation if it is determined that a type of constellation is a non-square constellation, the first type of symbol constellation extension projection having an outward angular region from an original position for the at least one symbol in the constellation, the outward angular region defined by a value for an angle between a first boundary and a second boundary for the outward angular region.
1. A method for processing a stream of data modulated into a plurality of symbols in a constellation as part of transmitting a signal, the method comprising:
applying one of a first type of symbol constellation extension projection to at least one symbol in the constellation if it is determined that a type of constellation is a non-square constellation, the first type of symbol constellation extension projection having an outward angular region from an original position for the at least one symbol in the constellation, the outward angular region defined by a value for an angle between a first boundary and a second boundary for the outward angular region, and
a second type of symbol constellation projection to at least one symbol in the constellation if it is determined that the type of constellation is a square constellation, the second type of symbol constellation extension projection representing a line in at least one of an x axis direction and a y axis direction,
wherein the applying one of the first type of symbol constellation projection and the second type of symbol constellation projection is determined by a selection of the constellation used as part of the transmitted signal and a code rate used for encoding the stream of data,
wherein the applying the first type of symbol constellation or the applying the second type of symbol constellation is determined by the following table:
Code Rate/
2/
3/
4/
5/
6/
7/
8/
9/
10/
11/
12/
13/
Constellation
15
15
15
15
15
15
15
15
15
15
15
15
QPSK
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
16 QAM
1D
2D
2D
2D
2D
2D
2D
2D
2D
1D
1D
1D
64 QAM
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
256 QAM
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
1024 QAM
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
4096 QAM
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D.
2. The method of claim 1 , wherein the constellation is at least one of a 16 QAM non-square constellation, a 64-QAM non-square constellation, and a 256-QAM non-square constellation.
3. The method of claim 1 , wherein the constellation is at least one of a 16 QAM square constellation, a QPSK square constellation, a 64-QAM square constellation, a 256-QAM square constellation, a 1024-QAM square constellation, and a 4096-QAM square constellation.
4. The method of claim 1 , wherein the first type of symbol constellation extension is a two dimensional (2D) symbol constellation projection and the second type of symbol constellation extension is a one dimensional (1D) symbol constellation extension.
5. The method of claim 1 , wherein the signal complies with the Advanced Television Standards Committee (ATSC) version 3.0 standard.
6. The method of claim 1 , further comprising;
performing a transform on the signal, including the at least one symbol, to produce a transform signal; and
modulating the transform signal to produce a transmitted signal.
7. The method of claim 1 , wherein the applying further includes:
performing a transform on the stream of data to convert the stream of data to a transform domain signal;
limiting the amplitude of the transform domain signal to produce a clipped transform signal;
performing an inverse transform on the clipped transform signal to produce an inverse transform signal;
subtracting the stream of data from the inverse transform signal to produce a remainder signal;
adjusting the signal level of the remainder signal by a pre-determined gain factor to produce an adjusted remainder signal; and
adding the stream of data to the adjusted remainder signal to produce an error signal.
8. The method of claim 6 , wherein performing a transform or performing an inverse transform uses a Fourier transform.
9. The method of claim 1 , wherein the method is used as part of an orthogonal frequency division multiplexing transmission.
10. The method of claim 1 , wherein the method is used as part of an active constellation extension for the signal.
11. The method of claim 10 , wherein an indication of the use of the active constellation extension for the signal is included in the transmitted signal.
12. The method of claim 11 , wherein the indication of use of the active constellation extension for the signal is included in L1 signaling portion of the transmitted signal.
13. The method of claim 1 , wherein the processing the stream of data is performed in order to reduce peak to average power ratio of the transmitted signal.
14. An apparatus for processing a stream of data converted into a plurality of symbols in a constellation as part of transmitting a signal, the apparatus comprising:
a pre-encoder including a projection module, the projection module applying one of a first type of symbol constellation extension projection to at least one symbol in the constellation if it is determined that a type of constellation is a non-square constellation, the first type of symbol constellation extension projection having an outward angular region from an original position for the at least one symbol in the constellation, the outward angular region defined by a value for an angle between a first boundary and a second boundary for the outward angular region, and
a second type of symbol constellation projection to at least one symbol in the constellation if it is determined that the type of constellation is a square constellation, the second type of symbol constellation extension projection formed from an original location for a symbol as a line extending in at least one of an x axis direction and a y axis direction,
wherein the applying one of the first type of symbol constellation projection and the second type of symbol constellation projection is determined by a selection of the constellation used as part of the transmitted signal and a code rate used for encoding the stream of data,
wherein the applying the first type of symbol constellation or the applying the second type of symbol constellation is determined by the following table:
Code Rate/
2/
3/
4/
5/
6/
7/
8/
9/
10/
11/
12/
13/
Constellation
15
15
15
15
15
15
15
15
15
15
15
15
QPSK
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
16 QAM
1D
2D
2D
2D
2D
2D
2D
2D
2D
1D
1D
1D
64 QAM
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
256 QAM
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
1024 QAM
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
4096 QAM
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D.
15. A method for processing a received signal transmitted as a constellation of symbols representing a data stream, the method comprising:
demodulating the received signal to provide an estimation of at least one symbol in the transmitted signal, the at least one symbol being included on one of a first extended constellation, the first extended constellation including at least one extended region formed as an outward angular sector from an original location for a symbol in the constellation if it is determined that a type of constellation is a non-square constellation, the outward angular region defined by a value for an angle between a first boundary and a second boundary for the outward angular region, and
a second extended constellation, the second extended constellation including at least one extended region formed from an original location for a symbol as a line extending in at least on of an x axis direction and a y axis direction, if it is determined that the type of constellation is a square constellation,
wherein determining one of the first extended constellation and the second extended constellation is based on a selection of the constellation size used as part of the transmitted signal and a code rate used for encoding the stream of data,
wherein the first extended constellation or the second extended constellation is determined by the following table:
Code Rate/
2/
3/
4/
5/
6/
7/
8/
9/
10/
11/
12/
13/
Constellation
15
15
15
15
15
15
15
15
15
15
15
15
QPSK
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
16 QAM
1D
2D
2D
2D
2D
2D
2D
2D
2D
1D
1D
1D
64 QAM
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
256 QAM
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
1024 QAM
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
4096 QAM
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D.
16. An apparatus for processing a received signal transmitted as a constellation of symbols representing a data stream, the apparatus comprising:
a demodulator that demodulates the received signal to provide an estimation of at least one symbol in the transmitted signal, the at least one symbol being included on one of a first extended constellation, the first extended constellation including at least one extended region formed as an outward angular sector from an original location for a symbol in the constellation if it is determined that a type of constellation is a non-square constellation, the outward angular region defined by a value for an angle between a first boundary and a second boundary for the outward angular region, and
a second extended constellation, the second extended constellation including at least one extended region formed from an original location for a symbol as a line extending in at least one of an x axis direction and a y axis direction, if it is determined that the type of constellation is a square constellation, wherein determining one of the first extended constellation and the second extended constellation is based on a selection of the constellation size used as part of the transmitted signal and a code rate used for encoding the stream of data,
wherein the first extended constellation or the second extended constellation is determined by the following table:
Code Rate/
2/
3/
4/
5/
6/
7/
8/
9/
10/
11/
12/
13/
Constellation
15
15
15
15
15
15
15
15
15
15
15
15
QPSK
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
16 QAM
1D
2D
2D
2D
2D
2D
2D
2D
2D
1D
1D
1D
64 QAM
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
256 QAM
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
1024 QAM
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
4096 QAM
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D.
17. A non-transitory device readable medium containing instructions for processing a received signal transmitted as a constellation of symbols representing a data stream, comprising:
demodulating the received signal to provide an estimation of at least one symbol in the transmitted signal, the at least one symbol being included on one of a first extended constellation, the first extended constellation including at least one extended region formed as an outward angular sector from an original location for a symbol in the constellation if it is determined that a type of constellation is a non-square constellation, the outward angular region defined by a value for an angle between a first boundary and a second boundary for the outward angular region, and
a second extended constellation, the second extended constellation including at least one extended region formed from an original location for a symbol as a line extending in at least one of an x axis direction and a y axis direction, if it is determined that the type of constellation is a square constellation,
wherein determining one of the first extended constellation and the second extended constellation is based on a selection of the constellation size used as part of the transmitted signal and the code rate used for encoding the stream of data,
wherein the first extended constellation or the second extended constellation is determined by the following table:
Code Rate/
2/
3/
4/
5/
6/
7/
8/
9/
10/
11/
12/
13/
Constellation
15
15
15
15
15
15
15
15
15
15
15
15
QPSK
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
16QAM
1D
2D
2D
2D
2D
2D
2D
2D
2D
1D
1D
1D
64QAM
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
256QAM
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
2D
1024QAM
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
4096QAM
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D
1D.
18. The apparatus of claim 14 , wherein the constellation is at least one of a 16 QAM non-square constellation, a 64-QAM non-square constellation, and a 256-QAM non-square constellation.
19. The apparatus of claim 14 , wherein the constellation is at least one of a 16 QAM square constellation, a QPSK square constellation, a 64-QAM square constellation, a 256-QAM square constellation, a 1024-QAM square constellation, and a 4096-QAM square constellation.
20. The apparatus of claim 14 , wherein the first type of symbol constellation extension is a two dimensional (2D) symbol constellation projection and the second type of symbol constellation extension is a one dimensional (1D) symbol constellation extension.
21. The apparatus of any of claims 14 , wherein the signal complies with the Advanced Television Standards Committee (ATSC) version 3.0 standard.
22. The apparatus of claim 14 wherein the pre-encoder further performs a transform on the signal, including the at least one symbol, to produce a transform signal, said apparatus further including:
a modulator that modulates the pre-encoded transform signal to produce a transmitted signal.
23. The apparatus of claim 14 wherein the pre-encoder further:
performs a transform on the stream of data to convert the stream of data to a transform domain signal,
limits the amplitude of the transform domain signal to produce a clipped transform signal;
performs an inverse transform on the clipped transform signal to produce an inverse transform signal,
subtracts the stream of data from the inverse transform signal to produce a remainder signal, adjusts the signal level of the remainder signal by a pre-determined gain factor to produce an adjusted remainder signal and
adds the stream of data to the adjusted remainder signal to produce an error signal.
24. The apparatus of claims 22 , wherein performing a transform or performing an inverse transform uses a Fourier transform.
25. The apparatus of claim 14 , wherein the method is used as part of an orthogonal frequency division multiplexing transmission.
26. The apparatus of claim 14 , wherein the apparatus is used as part of an active constellation extension for the signal.
27. The apparatus of claim 26 , wherein an indication of the use of the active constellation extension for the signal is included in the transmitted signal.
28. The apparatus of claim 27 , wherein the indication of use of the active constellation extension for the signal is included in L1 signaling portion of the transmitted signal.
29. The apparatus of claim 14 , wherein the processing the stream of data is performed in order to reduce peak to average power ratio of the transmitted signal.
30. The method of claim 15 , wherein the first extended constellation is at least one of a 16 QAM non-square constellation, a 64-QAM non-square constellation, and a 256-QAM non-square constellation.
31. The method of claim 15 , wherein the second extended constellation is at least one of a 16 QAM square constellation, a QPSK square constellation, a 64-QAM square constellation, a 256-QAM square constellation, a 1024-QAM square constellation, and a 4096-QAM square constellation.
32. The method of claim 15 , wherein the first extended constellation includes a two dimensional (2D) symbol constellation projection and the second extended constellation includes a one dimensional (1D) symbol constellation extension.
33. The method of claim 15 , wherein the signal complies with the Advanced Television Standards Committee (ATSC) version 3.0 standard.
34. The method of claim 15 , wherein a signal modulation is orthogonal frequency division multiplexing.
35. The method of claim 15 , wherein an indication of the use of an active constellation extension for the signal is included in the transmitted signal.
36. The method of claim 35 , wherein the indication of use of the active constellation extension for the signal is included in L1 signaling portion of the transmitted signal.
37. The apparatus of claim 16 , wherein the first extended constellation is at least one of a 16 QAM non-square constellation, a 64-QAM non-square constellation, and a 256-QAM non-square constellation.
38. The apparatus of claim 16 , wherein the second extended constellation is at least one of a 16 QAM square constellation, a QPSK square constellation, a 64-QAM square constellation, a 256-QAM square constellation, a 1024-QAM square constellation, and a 4096-QAM square constellation.
39. The apparatus of claim 16 , wherein the first extended constellation includes a two dimensional (2D) symbol constellation projection and the second extended constellation includes a one dimensional (1D) symbol constellation extension.
40. The apparatus of claim 16 , wherein the signal complies with the Advanced Television Standards Committee (ATSC) version 3.0 standard.
41. The apparatus of claim 16 , wherein a signal modulation is orthogonal frequency division multiplexing.
42. The apparatus of claim 16 , wherein an indication of the use of an active constellation extension for the signal is included in the transmitted signal.
43. The apparatus of claim 42 , wherein the indication of use of the active constellation extension for the signal is included in L1 signaling portion of the transmitted signal.