Transmission device, reception device, transmission method, and reception method

• US 10,567,016 B2
• Filed: 02/08/2019
• Issued: 02/18/2020
• Est. Priority Date: 08/12/2016
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Inventors: Kimura, Tomohiro, Ouchi, Mikihiro
• Primary Examiner(s): Joseph, Jaison
• Application Number:
  US16/270,930
• Publication Number:
  US 20190173502A1
• Time in Patent Office: 375 Days
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04J 13/0003 Code application, i.e. aspects relating to how codes are applied to form multiplexed channels
• CPC Class Codes: H04J 7/02 in which the polarity of the amplitude is characteristic
• CPC Class Codes: H04L 27/3488 Multiresolution systems

Abstract

A transmission device includes a first mapper, a second mapper, a converter, a superposer, and a transmitter. The first mapper is configured to map a first bit stream of a first data series to generate a first modulated symbol stream. The second mapper is configured to map a second bit stream of a second data series to generate a second modulated symbol stream. The first modulated symbol stream and the second modulated symbol stream are representable on a complex plane extending in a first direction and a second direction. The converter is configured to convert the second modulated symbol stream in accordance with the first modulated symbol stream only in the first direction on the complex plane. The superposer is configured to superpose the first modulated symbol stream and the second modulated symbol stream converted by the converter, at an amplitude ratio, to generate a multiplexed signal.

Claims

1. A transmission device comprising:

a first mapper configured to map a first bit stream of a first data series to generate a first modulated symbol stream;

a second mapper configured to map a second bit stream of a second data series to generate a second modulated symbol stream, the first modulated symbol stream and the second modulated symbol stream being representable on a complex plane extending in a first direction and a second direction perpendicular to the first direction;

a converter configured to convert the second modulated symbol stream in accordance with the first modulated symbol stream only in the first direction on the complex plane;

a superposer configured to superpose the first modulated symbol stream and the second modulated symbol stream converted by the converter, at an amplitude ratio, to generate a multiplexed signal; and

a transmitter configured to transmit the multiplexed signal.

2. The transmission device according to claim 1, wherein

the converter controls a polarity of a component that each of modulated symbols in the second modulated symbol stream includes in the first direction, by converting the second modulated symbol stream.

3. The transmission device according to claim 2, wherein

in superposing the first modulated symbol stream and the second modulated symbol stream, the superposer superposes a first modulated symbol in the first modulated symbol stream and a second modulated symbol in the second modulated symbol stream in which the polarity is controlled, and

in controlling the polarity, when a component that the first modulated symbol includes in the first direction satisfies a predetermined condition, the converter reverses a polarity of a component that the second modulated symbol includes in the first direction.

4. The transmission device according to claim 1, wherein

the converter converts the second modulated symbol stream by converting the second bit stream, a constellation used to map the second bit stream, or the second modulated symbol stream, in accordance with the first bit stream or the first modulated symbol stream.

5. The transmission device according to claim 1, wherein

the first mapper maps the first bit stream by use of a first constellation in which a plurality of signal points are dispersed in only the first direction among the first direction and the second direction, and

the second mapper maps the second bit stream by use of a second constellation in which a plurality of signal points are dispersed in both the first direction and the second direction.

6. The transmission device according to claim 5, wherein

the second constellation used by the second mapper to map the second bit stream is a constellation in which noise tolerance in the first direction is higher than noise tolerance in the second direction.

7. The transmission device according to claim 5, wherein

the second constellation used by the second mapper to map the second bit stream is a constellation in which a multilevel number in the first direction is smaller than a multilevel number in the second direction.

8. The transmission device according to claim 5, wherein

the multiplexed signal generated by the superposer is a signal on which (i) a first modulated symbol in the first modulated symbol stream, (ii) a first component that a second modulated symbol in the second modulated symbol stream includes in the first direction, and (iii) a second component that the second modulated symbol includes in the second direction are superposed, and

a proportion of the first component superposed on the multiplexed signal is lower than a proportion of the second component superposed on the multiplexed signal.

9. The transmission device according to claim 5, wherein

the converter controls a polarity of a component that each of modulated symbols in the second modulated symbol stream includes in the first direction, by converting the second modulated symbol stream,

in superposing the first modulated symbol stream and the second modulated symbol stream, the superposer superposes a first modulated symbol in the first modulated symbol stream and a second modulated symbol in the second modulated symbol stream in which the polarity is controlled, and

in controlling the polarity, the converter reverses a polarity of a component that the second modulated symbol includes in the first direction when the first modulated symbol corresponds to one of two signal points adjacent to each other in the first constellation, and maintains the polarity of the component that the second modulated symbol includes in the first direction when the first modulated symbol corresponds to the other of the two signal points.

10. The transmission device according to claim 1,

wherein the superposer is configured to generate the multiplexed signal for multiple access,

wherein the first data series is provided for a first reception device, and

wherein the second data series is provided for a second reception device.

11. The transmission device according to claim 1, wherein the first direction is provided along one of a real axis and an imaginary axis of the complex plane.

12. The transmission device according to claim 1, wherein the converter reverses a polarity of a real part of a second modulated symbol included in the second modulated symbol stream if a first modulated symbol included in the first modulated symbol stream has a positive real part.

13. A reception device comprising:

a receiver configured to receive a multiplexed signal on which a first modulated symbol stream and a second modulated symbol stream are superposed at an amplitude ratio, the first modulated symbol stream being generated by mapping a first bit stream of a first data series, the second modulated symbol stream being generated by mapping a second bit stream of a second data series, the first modulated symbol stream and the second modulated symbol stream being representable on a complex plane extending in a first direction and a second direction perpendicular to the first direction; and

a deriver configured to derive at least one of the first data series or the second data series from the multiplexed signal, wherein

the receiver receives the multiplexed signal on which the second modulated symbol stream is converted in accordance with the first modulated symbol stream only in the first direction on the complex plane.

14. The reception device according to claim 13,

wherein the receiver is configured to receive the multiplexed signal provided for multiple access,

wherein the deriver is configured to derive only the first data series, and

wherein the second data series is provided to be derived in another reception device.

15. The reception device according to claim 13, wherein the first direction is provided along one of a real axis and an imaginary axis of the complex plane.

16. The reception device according to claim 13, wherein the receiver receives the multiplexed signal in which a polarity of a real part of a second modulated symbol included in the second modulated symbol stream is reversed and in which a first modulated symbol included in the first modulated symbol stream has a positive real part.

17. A transmission method comprising:

mapping a first bit stream of a first data series to generate a first modulated symbol stream;

mapping a second bit stream of a second data series to generate a second modulated symbol stream, the first modulated symbol stream and the second modulated symbol stream being representable on a complex plane extending in a first direction and a second direction perpendicular to the first direction;

converting the second modulated symbol stream in accordance with the first modulated symbol stream only in the first direction on the complex plane;

superposing the first modulated symbol stream and the second modulated symbol stream, at an amplitude ratio, to generate a multiplexed signal after the second modulated symbol stream is converted; and

transmitting the multiplexed signal.

18. The transmission method according to claim 17, wherein

a polarity of a component that each of modulated symbols in the second modulated symbol stream includes in the first direction is controlled by converting the second modulated symbol stream being subjected.

19. The transmission method according to claim 18, wherein

in superposing the first modulated symbol stream and the second modulated symbol stream, a first modulated symbol in the first modulated symbol stream and a second modulated symbol in the second modulated symbol stream in which the polarity is controlled are superposed, and

in controlling the polarity, when a component that the first modulated symbol includes in the first direction satisfies a predetermined condition, a polarity of a component that the second modulated symbol includes in the first direction is reversed.

20. The transmission method according to claim 17, wherein

the second modulated symbol stream is converted by converting the second bit stream, a constellation used to map the second bit stream, or the second modulated symbol stream, in accordance with the first bit stream or the first modulated symbol stream.

21. The transmission method according to claim 17, wherein

in mapping the first bit stream, a first constellation is used to map the first bit stream, the first constellation being a constellation in which a plurality of signal points are dispersed in only the first direction among the first direction and the second direction, and

in mapping the second bit stream, a second constellation is used to map the second bit stream, the second constellation being a constellation in which a plurality of signal points are dispersed in both the first direction and the second direction.

22. The transmission method according to claim 21, wherein

in mapping the second bit stream, the second constellation used to map the second bit stream is a constellation in which noise tolerance in the first direction is higher than noise tolerance in the second direction.

23. The transmission method according to claim 21, wherein

in mapping the second bit stream, the second constellation used to map the second bit stream is a constellation in which a multilevel number in the first direction is smaller than a multilevel number in the second direction.

24. The transmission method according to claim 21, wherein

in generating the multiplexed signal, the multiplexed signal generated is a signal on which (i) a first modulated symbol in the first modulated symbol stream, (ii) a first component that a second modulated symbol in the second modulated symbol stream includes in the first direction, and (iii) a second component that the second modulated symbol includes in the second direction are superposed, and

a proportion of the first component superposed on the multiplexed signal is lower than a proportion of the second component superposed on the multiplexed signal.

25. The transmission method according to claim 21, wherein

a polarity of a component that each of modulated symbols in the second modulated symbol stream includes in the first direction is controlled by the second modulated symbol stream being converted,

in superposing the first modulated symbol stream and the second modulated symbol stream, a first modulated symbol in the first modulated symbol stream and a second modulated symbol in the second modulated symbol stream in which the polarity is controlled are superposed, and

in controlling the polarity, a polarity of a component that the second modulated symbol includes in the first direction is reversed when the first modulated symbol corresponds to one of two signal points adjacent to each other in the first constellation, and the polarity of the component that the second modulated symbol includes in the first direction is maintained when the first modulated symbol corresponds to the other of the two signal points.

26. A reception method comprising:

receiving a multiplexed signal on which a first modulated symbol stream and a second modulated symbol stream are superposed at an amplitude ratio, the first modulated symbol stream being generated by mapping a first bit stream of a first data series, the second modulated symbol stream being generated by mapping a second bit stream of a second data series, the first modulated symbol stream and the second modulated symbol stream being representable on a complex plane extending in a first direction and a second direction perpendicular to the first direction; and

deriving at least one of the first data series or the second data series from the multiplexed signal, wherein

the second modulated symbol stream is converted in accordance with the first modulated symbol stream only in the first direction on the complex plane when the multiplexed signal is received.