Methods and apparatuses for signaling with geometric constellations in a Raleigh fading channel

• US 10,524,139 B2
• Filed: 08/21/2017
• Issued: 12/31/2019
• Est. Priority Date: 06/05/2007
• Status: Active Grant

• Current Assignee: Constellation Designs, LLC (SoftBank Group Corp.)
• Original Assignee: Constellation Designs, LLC (SoftBank Group Corp.)
• Inventors: Barsoum, Maged F., Jones, Christopher R.
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US15/682,512
• Publication Number:
  US 20170374565A1
• Time in Patent Office: 862 Days
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 27/3405 Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/0473 the resource being transmission power

Abstract

Communication systems are described that use signal constellations which have unequally spaced (i.e. “geometrically spaced,” or “non-uniform”) points. In many embodiments, the transmitters and receivers use specific non-uniform quadrature amplitude modulation (NU-QAM) constellations. In a variety of embodiments, NU-QAM constellations are capacity optimized using a bit-interleaved coded modulation (BICM, also referred to as “parallel decode”) capacity measure. In a number of embodiments, the transmitters and receivers are described that use specific NU-QAM constellations that provide gains in BICM capacity relative to constellations that maximize the minimum distance between constellation points.

Claims

1. A digital communication system, comprising:

a transmitter configured to transmit signals to a receiver via a communication channel;

wherein the transmitter comprises;

a coder configured to receive user bits and output encoded bits at an expanded output encoded bit rate;

a mapper configured to map encoded bits to symbols in a non-uniform quadrature amplitude modulation 1024-point symbol constellation (NU-QAM

     1024);

a modulator configured to generate a signal for transmission via the communication channel using symbols generated by the mapper;

wherein the receiver comprises;

a demodulator configured to demodulate a signal received via the communication channel;

a demapper configured to estimate likelihoods from a demodulated signal based upon the NU-QAM 1024; and

a decoder configured to estimate decoded bits from likelihoods generated by the demapper and output a sequence of received bits;

wherein the NU-QAM 1024 comprises an in-phase component and a quadrature component, where each component comprises 32 levels of amplitude such that the amplitudes scaled by a scaling factor are within 1.5960 from the following set of amplitudes;

−

37.9896, −

30.4644, −

25.8467, −

26.1314, −

17.8829, −

18.1165, −

18.8919, −

18.8919, −

4.8867, −

4.9004, −

4.9384, −

4.9384, −

8.2966, −

8.2966, −

8.2966, −

8.2966, 37.9896, 30.4644, 25.8467, 26.1314, 17.884, 18.1156, 18.8918, 18.8918, 4.8863, 4.9008, 4.9384, 4.9384, 8.2966, 8.2966, 8.2966, 8.2966.

2. The digital communication system of claim 1, wherein each component comprises 32 levels of amplitude such that the amplitudes scaled by a scaling factor are within 0.6870 from the following set of amplitudes:

−

37.9896, −

30.4644, −

25.8467, −

26.1314, −

17.8829, −

18.1165, −

18.8919, −

18.8919, −

4.8867, −

4.9004, −

4.9384, −

4.9384, −

8.2966, −

8.2966, −

8.2966, −

8.2966, 37.9896, 30.4644, 25.8467, 26.1314, 17.884, 18.1156, 18.8918, 18.8918, 4.8863, 4.9008, 4.9384, 4.9384, 8.2966, 8.2966, 8.2966, 8.2966.

3. The digital communication system of claim 1, wherein each component comprises 32 levels of amplitude such that the amplitudes scaled by a scaling factor are:

−

37.9896, −

30.4644, −

25.8467, −

26.1314, −

17.8829, −

18.1165, −

18.8919, −

18.8919, −

4.8867, −

4.9004, −

4.9384, −

4.9384, −

8.2966, −

8.2966, −

8.2966, −

8.2966, 37.9896, 30.4644, 25.8467, 26.1314, 17.884, 18.1156, 18.8918, 18.8918, 4.8863, 4.9008, 4.9384, 4.9384, 8.2966, 8.2966, 8.2966, 8.2966.

4. The digital communication system of claim 1, wherein the receiver is configured to select the NU-QAM 1024 constellation from a plurality of constellations including a plurality of NU-QAM 1024 constellations.

5. The digital communication system of claim 1, wherein the receiver is configured to select a code rate and the NU-QAM 1024 constellation from a plurality of combinations of code rates and NU-QAM 1024 constellations.

6. The digital communication system of claim 1, wherein:

the coder is configured to encode bits using a low-density parity check (LDPC) code; and

the decoder is configured to decode bits using the LDPC code.

7. The digital communication system of claim 1, wherein the symbols in the non-uniform quadrature amplitude modulation 1024-point symbol constellation (NU-QAM 1024) are labelled using gray labels.

8. The digital communication system of claim 7, wherein the symbols in the non-uniform quadrature amplitude modulation 1024-point symbol constellation (NU-QAM 1024) are labelled using binary reflective gray labels.

9. A digital communication system, comprising:

a transmitter configured to transmit signals via a communication channel;

wherein the transmitter comprises;

a coder capable of receiving user bits and output encoded bits at an expanded output encoded bit rate;

a mapper capable of mapping encoded bits to symbols in a non-uniform quadrature amplitude modulation 1024-point symbol constellation (NU-QAM

     1024);

a modulator capable of generating a signal for transmission via the communication channel using symbols generated by the mapper;

wherein the NU-QAM 1024 comprises an in-phase component and a quadrature component, where each component comprises 32 levels of amplitude such that the amplitudes scaled by a scaling factor are within 1.5960 from the following set of amplitudes;

−

37.9896, −

30.4644, −

25.8467, −

26.1314, −

17.8829, −

18.1165, −

18.8919, −

18.8919, −

4.8867, −

4.9004, −

4.9384, −

4.9384, −

8.2966, −

8.2966, −

8.2966, −

8.2966, 37.9896, 30.4644, 25.8467, 26.1314, 17.884, 18.1156, 18.8918, 18.8918, 4.8863, 4.9008, 4.9384, 4.9384, 8.2966, 8.2966, 8.2966, 8.2966.

10. The digital communication system of claim 9, wherein each component comprises 32 levels of amplitude such that the amplitudes scaled by a scaling factor are within 0.6870 from the following set of amplitudes:

−

37.9896, −

30.4644, −

25.8467, −

26.1314, −

17.8829, −

18.1165, −

18.8919, −

18.8919, −

4.8867, −

4.9004, −

4.9384, −

4.9384, −

8.2966, −

8.2966, −

8.2966, −

8.2966, 37.9896, 30.4644, 25.8467, 26.1314, 17.884, 18.1156, 18.8918, 18.8918, 4.8863, 4.9008, 4.9384, 4.9384, 8.2966, 8.2966, 8.2966, 8.2966.

11. The digital communication system of claim 9, wherein each component comprises 32 levels of amplitude such that the amplitudes scaled by a scaling factor are:

−

37.9896, −

30.4644, −

25.8467, −

26.1314, −

17.8829, −

18.1165, −

18.8919, −

18.8919, −

4.8867, −

4.9004, −

4.9384, −

4.9384, −

8.2966, −

8.2966, −

8.2966, −

8.2966, 37.9896, 30.4644, 25.8467, 26.1314, 17.884, 18.1156, 18.8918, 18.8918, 4.8863, 4.9008, 4.9384, 4.9384, 8.2966, 8.2966, 8.2966, 8.2966.

12. The digital communication system of claim 9, wherein the transmitter is capable of selecting the NU-QAM 1024 constellation from a plurality of constellations including a plurality of NU-QAM 1024 constellations.

13. The digital communication system of claim 9, wherein the transmitter is capable of selecting a code rate and the NU-QAM 1024 constellation from a plurality of combinations of code rates and NU-QAM 1024 constellations.

14. The digital communication system of claim 9, wherein the coder is capable of encoding bits using a low-density parity check-code (LDPC).

15. The digital communication system of claim 9, wherein the symbols in the non-uniform quadrature amplitude modulation 1024-point symbol constellation (NU-QAM 1024) are labelled using gray labels.

16. The digital communication system of claim 15, wherein the symbols in the non-uniform quadrature amplitude modulation 1024-point symbol constellation (NU-QAM 1024) are labelled using binary reflective gray labels.

17. A digital communication system, comprising:

a receiver configured to receive signals via a communication channel;

wherein the receiver comprises;

a demodulator capable of demodulating a signal received via the communication channel;

a demapper capable of estimating likelihoods from a demodulated signal based upon a non-uniform quadrature amplitude modulation 1024-point symbol constellation (NU-QAM 1024 ); and

a decoder capable of estimating decoded bits from likelihoods generated by the demapper and outputting a sequence of received bits; and

wherein the NU-QAM 1024 comprises an in-phase component and a quadrature component, where each component comprises 32 levels of amplitude such that the amplitudes scaled by a scaling factor are within 1.5960 from the following set of amplitudes;

−

37.9896, −

30.4644, −

25.8467, −

26.1314, −

17.8829, −

18.1165, −

18.8919, −

18.8919, −

4.8867, −

4.9004, −

4.9384, −

4.9384, −

8.2966, −

8.2966, −

8.2966, −

8.2966, 37.9896, 30.4644, 25.8467, 26.1314, 17.884, 18.1156, 18.8918, 18.8918, 4.8863, 4.9008, 4.9384, 4.9384, 8.2966, 8.2966, 8.2966, 8.2966.

18. The digital communication system of claim 17, wherein each component comprises 32 levels of amplitude such that the amplitudes scaled by a scaling factor are within 0.6870 from the following set of amplitudes:

−

37.9896, −

30.4644, −

25.8467, −

26.1314, −

17.8829, −

18.1165, −

18.8919, −

18.8919, −

4.8867, −

4.9004, −

4.9384, −

4.9384, −

8.2966, −

8.2966, −

8.2966, −

8.2966, 37.9896, 30.4644, 25.8467, 26.1314, 17.884, 18.1156, 18.8918, 18.8918, 4.8863, 4.9008, 4.9384, 4.9384, 8.2966, 8.2966, 8.2966, 8.2966.

19. The digital communication system of claim 17, wherein each component comprises 32 levels of amplitude such that the amplitudes scaled by a scaling factor are:

−

37.9896, −

30.4644, −

25.8467, −

26.1314, −

17.8829, −

18.1165, −

18.8919, −

18.8919, −

4.8867, −

4.9004, −

4.9384, −

4.9384, −

8.2966, −

8.2966, −

8.2966, −

8.2966, 37.9896, 30.4644, 25.8467, 26.1314, 17.884, 18.1156, 18.8918, 18.8918, 4.8863, 4.9008, 4.9384, 4.9384, 8.2966, 8.2966, 8.2966, 8.2966.

20. The digital communication system of claim 17, wherein the receiver is capable of selecting the NU-QAM 1024 constellation from a plurality of constellations including a plurality of NU-QAM 1024 constellations.

21. The digital communication system of claim 17, wherein the receiver is capable of selecting a code rate and the NU-QAM 1024 constellation from a plurality of combinations of code rates and NU-QAM 1024 constellations.

22. The digital communication system of claim 17, wherein the decoder is capable of decoding bits using a low-density parity check-code (LDPC).

23. The digital communication system of claim 17, wherein the symbols in the non-uniform quadrature amplitude modulation 1024-point symbol constellation (NU-QAM 1024) are labelled using gray labels.

24. The digital communication system of claim 23, wherein the symbols in the non-uniform quadrature amplitude modulation 1024-point symbol constellation (NU-QAM 1024) are labelled using binary reflective gray labels.