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 symbol constellation extension projection to at least one symbol in the constellation, the 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, the value for the angle 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.
1. A method for processing a stream of data converted into a plurality of symbols in a constellation as part of transmitting a signal, the method comprising:
applying a symbol constellation extension projection to at least one symbol in the constellation, the 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, the value for the angle 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 value for the angle based on the constellation and the code rate equals the values given in the following table:
Code Rate/Constellation
2/15
3/15
4/15
5/15
6/15
7/15
16QAM
NA
33.26°
35.6°
38.5°
44.14°
44.1°
64QAM
22.96°
39.36°
41.26°
19.01°
21.17°
22.49°
256QAM
36.67°
40.26°
19.11°
22.47°
8.38°
11.23°
Code Rate/Constellation
8/15
9/15
10/15
11/15
12/15
13/15
16QAM
44.49°
44.49°
42.1°
NA
NA
NA
64QAM
22.28°
22.49°
22.4°
19.75°
18.42°
16.81°
256QAM
11.23°
10.93°
11.22°
10.63°
8.8°
8.34°.
2. The method of claim 1 wherein the outward angular region is formed between two boundary lines, the two boundary lines being non-orthogonal to each other.
3. The method of claim 1 , wherein the angle between the two boundary is equal to or less than the angle formed between a projection line from an origin point in the constellation and the at least one symbol and a projection line from the origin point in the constellation and a symbol adjacent to the at least one symbol.
4. 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.
5. The method of claim 1 , wherein the constellation is a non-uniform constellation.
6. The method of claim 1 , wherein the signal complies with the Advanced Television Standards Committee (ATSC) version 3.0 standard.
7. The method of claim 1 , further comprising:
performing a transform on the signal, including the at least one symbol having the symbol constellation extension projection, to produce a transform signal; and
modulating the transform signal to produce a transmitted signal.
8. 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.
9. The method of claim 1 , wherein performing a transform or performing an inverse transform uses a Fourier transform.
10. The method of claim 1 , wherein the method is used as part of an orthogonal frequency division multiplexing transmission.
11. The method of claim 1 , wherein the method is used as part of a two dimensional active constellation extension for the signal.
12. The method of claim 11 , wherein an indication of the use of the two dimensional active constellation extension for the signal is included in the transmitted signal.
13. The method of claim 12 , wherein the indication of use of the two dimensional active constellation extension for the signal is included in LI signaling portion of the transmitted signal.
14. 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.
15. An apparatus for processing a stream of data converted into a plurality of symbols in a constellation as part of transmitting a signal, comprising:
a pre-encoder including a projection module, the projection module applying a symbol constellation extension projection to at least one symbol in the constellation, the 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, the value for the angle 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 value for the angle based on the constellation and the code rate equals the values given in the following table:
Code Rate/Constellation
2/15
3/15
4/15
5/15
6/15
7/15
8/15
9/15
10/15
11/15
12/15
13/15
16QAM
NA
33.26°
35.6°
38.5°
44.14°
44.1°
44.49°
44.49°
42.1°
NA
NA
NA
64QAM
22.96°
39.36°
41.26°
19.01°
21.17°
22.49°
22.28°
22.49°
22.4°
19.75°
18.42°
16.81°
256QAM
36.67°
40.26°
19.11°
22.47°
8.38°
11.23°
11.23°
10.93°
11.22°
10.63°
8.8°
8.34°.
16. 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 on an extended constellation, the extended constellation including at least one extended region formed as an outward angular sector from an original location for a 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, the value for the angle determined by a selection of the constellation used as part of the transmitted signal and a code rate for the data stream in the signal,
wherein the value for the angle based on the constellation and the code rate equals the values given in the following table:
Code Rate/Constellation
2/15
3/15
4/15
5/15
6/15
7/15
8/15
9/15
10/15
11/15
12/15
13/15
16QAM
NA
33.26°
35.6°
38.5°
44.14°
44.1°
44.49°
44.49°
42.1°
NA
NA
NA
64QAM
22.96°
39.36°
41.26°
19.01°
21.17°
22.49°
22.28°
22.49°
22.4°
19.75°
18.42°
16.81°
256QAM
36.67°
40.26°
19.11°
22.47°
8.38°
11.23°
11.23°
10.93°
11.22°
10.63°
8.8°
8.34°.
17. An apparatus for processing a received signal transmitted as a constellation of symbols representing a data stream that has been encoded using a code rate, the apparatus comprising:
a demodulator that demodulates the received signal to provide an estimation of at least one symbol in the transmitted signal on an extended constellation, the extended constellation including at least one extended region formed as an outward angular sector from an original location for a 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, the value for the angle determined by a selection of the constellation used as part of the transmitted signal and the code rate for the data stream in the signal,
wherein the value for the angle based on the constellation and the code rate equals the values given in the following table:
Code Rate/Constellation
2/15
3/15
4/15
5/15
6/15
7/15
8/15
9/15
10/15
11/15
12/15
13/15
16QAM
NA
33.26°
35.6°
38.5°
44.14°
44.1°
44.49°
44.49°
42.1°
NA
NA
NA
64QAM
22.96°
39.36°
41.26°
19.01°
21.17°
22.49°
22.28°
22.49°
22.4°
19.75°
18.42°
16.81°
256QAM
36.67°
40.26°
19.11°
22.47°
8.38°
11.23°
11.23°
10.93°
11.22°
10.63°
8.8°
8.34°.
18. 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 on an extended constellation, the extended constellation including at least on extended region formed as an outward angular sector from an original location for a 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, the value for the angle determined by a selection of the constellation used as part of the transmitted signal and the code rate for the data stream in the signal,
wherein the value for the angle based on the constellation and the code rate equals the values given in 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
16QAM
NA
33.26°
35.6°
38.5°
44.14°
44.1°
44.49°
44.49°
42.1°
NA
NA
NA
64QAM
22.96°
39.36°
41.26°
19.01°
21.17°
22.49°
22.28°
22.49°
22.4°
19.75°
18.42°
16.81°
256QAM
36.67°
40.26°
19.11°
22.47°
8.38°
11.23°
11.23°
10.93°
11.22°
10.63°
8.8°
8.34°.
19. The apparatus of claim 15 wherein the outward angular region is formed between two boundary lines, the two boundary lines being non-orthogonal to each other.
20. The apparatus of claim 15 , wherein the angle between the two boundary is equal to or less than the angle formed between a projection line from an origin point in the constellation and the at least one symbol and a projection line from the origin point in the constellation and a symbol adjacent to the at least one symbol.
21. The apparatus of claim 15 , 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.
22. The apparatus of claim 15 , wherein the constellation is a non-uniform constellation.
23. The apparatus of claim 15 , wherein the signal complies with the Advanced Television Standards Committee (ATSC) version 3.0 standard.
24. The apparatus of claim 15 wherein the pre-encoder ( 600 ) further performs a transform on the signal, including the at least one symbol having the symbol constellation extension projection, to produce a transform signal, the apparatus further including:
a modulator that modulates the pre-encoded transform signal to produce a transmitted signal.
25. The apparatus of claim 16 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.
26. The apparatus of claim 24 , wherein performing a transform or performing an inverse transform uses a Fourier transform.
27. The method of claim 15 , wherein the apparatus is used as part of an orthogonal frequency division multiplexing transmission.
28. The apparatus of claim 15 , wherein the apparatus is used as part of a two dimensional active constellation extension for the signal.
29. The apparatus of claim 28 , wherein an indication of the use of the two dimensional active constellation extension for the signal is included in the transmitted signal.
30. The apparatus of claim 29 , wherein the indication of use of the two dimensional active constellation extension for the signal is included in LI signaling portion of the transmitted signal.
31. The apparatus of claim 15 , wherein the processing the stream of data is performed in order to reduce peak to average power ratio of the transmitted signal.
32. The method of claim 16 wherein the outward angular region is formed between two boundary lines, the two boundary lines being non-orthogonal to each other.
33. The method of claim 16 , wherein the angle between the two boundary is equal to or less than the angle formed between a projection line from an origin point in the constellation and the at least one symbol and a projection line from the origin point in the constellation and a symbol adjacent to the at least one symbol.
34. The method of claim 16 , 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.
35. The method of claim 16 , wherein the constellation is a non-uniform constellation.
36. The method of claim 16 , wherein the signal complies with the Advanced Television Standards Committee (ATSC) version 3.0 standard.
37. The method of claim 16 , wherein a signal modulation is orthogonal frequency division multiplexing.
38. The method of claim 16 , wherein an indication of the use of a two dimensional active constellation extension for the signal is included in the transmitted signal.
39. The method of claim 38 , wherein the indication of use of the two dimensional active constellation extension for the signal is included in LI signaling portion of the transmitted signal.
40. The apparatus of claim 17 wherein the outward angular region is formed between two boundary lines, the two boundary lines being non-orthogonal to each other.
41. The apparatus of claim 17 , wherein the angle between the two boundary is equal to or less than the angle formed between a projection line from an origin point in the constellation and the at least one symbol and a projection line from the origin point in the constellation and a symbol adjacent to the at least one symbol.
42. The apparatus of claim 17 , 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.
43. The apparatus of claim 17 , wherein the constellation is a non-uniform constellation.
44. The apparatus of claim 17 , wherein the signal complies with the Advanced Television Standards Committee (ATSC) version 3.0 standard.
45. The apparatus of claim 17 , wherein a signal modulation is orthogonal frequency division multiplexing.
46. The apparatus of claim 17 , wherein an indication of the use of a two dimensional active constellation extension for the signal is included in the transmitted signal.
47. The apparatus of claim 46 , wherein the indication of use of the two dimensional active constellation extension for the signal is included in LI signaling portion of the transmitted signal.