Methods and apparatuses for signaling with geometric constellations

• US 8,265,175 B2
• Filed: 12/30/2009
• Issued: 09/11/2012
• Est. Priority Date: 06/05/2007
• Status: Active Grant

• Current Assignee: Constellation Designs, LLC (FIG LLC (d/b/a Fortress Investment Group LLC))
• Original Assignee: Constellations Designs, Inc.
• Inventors: Barsoum, Maged F., Jones, Christopher R.
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US12/650,532
• Publication Number:
  US 20100195743A1
• Time in Patent Office: 986 Days
• Field of Search: 375/260, 375/267, 375/262, 375/268, 375/295, 375/316, 375/259, 375/261, 375/298, 375/279, 375/280, 375/308, 375/329, 375/332, 375/341, 375/340, 375/322, 332/103, 329/304
• US Class Current: 375/259
• CPC Class Codes: A61B 2017/00703 correcting for movement of heart, e.g. ECG-triggered
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/376 using X-rays, e.g. fluoroscopy
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/503 for diagnosis of the heart
• CPC Class Codes: A61B 6/5235 combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT
• CPC Class Codes: A61B 6/5264 due to motion
• CPC Class Codes: A61B 6/527 using data from a motion artifact sensor
• CPC Class Codes: G06T 2207/10121 Fluoroscopy
• CPC Class Codes: G06T 2207/30021 Catheter; Guide wire
• CPC Class Codes: G06T 2207/30048 Heart; Cardiac
• CPC Class Codes: G06T 7/33 using feature-based methods
• CPC Class Codes: H04B 14/023 using pulse amplitude modulation
• 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

Abstract

Communication systems are described that use signal constellations, which have unequally spaced (i.e. ‘geometrically’ shaped) points. In many embodiments, the communication systems use specific geometric constellations that are capacity optimized at a specific SNR. In addition, ranges within which the constellation points of a capacity optimized constellation can be perturbed and are still likely to achieve a given percentage of the optimal capacity increase compared to a constellation that maximizes d_min, are also described. Capacity measures that are used in the selection of the location of constellation points include, but are not limited to, parallel decode (PD) capacity and joint capacity.

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 said encoded bits to symbols in a symbol, constellation;

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 the received signal, via the communication channel;

a demapper configured to estimate likelihoods from the demodulated signal;

a decoder that is configured to estimate decoded bits from the likelihoods generated by the demapper; and

wherein the points of the symbol, constellation have non-uniform inter-point distances selected to achieve a gain in capacity for a predetermined signal, to noise ratio (SNR) relative to a symbol, constellation having uniform inter-point distances.

2. The communication system of claim 1, wherein the code is a Turbo code.

3. The communication system of claim 1, wherein the code is a LDPC code.

4. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 5% of the gain in capacity achieved by a constellation optimized for joint capacity at the predetermined SNR.

5. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 15% of the gain in capacity achieved by a constellation optimized for joint capacity at the predetermined SNR.

6. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 30% of the gain in capacity achieved by a constellation optimized for joint capacity at the predetermined SNR.

7. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 45% of the gain in capacity achieved by a constellation optimized for joint capacity at the predetermined SNR.

8. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 60% of the gain in capacity achieved by a constellation optimized for joint capacity at the predetermined SNR.

9. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 100% of the gain in capacity achieved by a constellation optimized for joint capacity at the predetermined SNR.

10. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 5% of the gain in capacity achieved by a constellation optimized for PD capacity at the predetermined SNR.

11. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 40% of the gain in capacity achieved by a constellation optimized for PD capacity at the predetermined SNR.

12. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 50% of the gain in capacity achieved by a constellation optimized for PD capacity at the predetermined SNR.

13. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 60% of the gain in capacity achieved by a constellation optimized for PD capacity at the predetermined SNR.

14. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 70% of the gain in capacity achieved by a constellation optimized for PD capacity at the predetermined SNR.

15. The communication system of claim 1, wherein the constellation provides an increase in capacity at a predetermined SNR that is at least 100% of the gain in capacity achieved by a constellation optimized for PD capacity at the predetermined SNR.

16. The communication system of claim 1,

wherein the symbol, constellation is a PAM-16 symbol, constellation having constellation points within at least one of the ranges specified in FIGS. 47-84.

17. The communication system of claim 1,

wherein the symbol, constellation is a PAM-32 symbol, constellation having constellation points within at least one of the ranges specified in FIGS. 85-148.

18. The communication system of claim 1,

wherein the symbol, constellation is a N-Dimensional, symbol, constellation, where the constellation points in at least one dimension are within at least one of the ranges specified in FIGS. 25-167.

19. The communication system of claim 1, wherein the symbol, constellation is a PAM-8 symbol, constellation having constellation points within at least one of the ranges specified in FIGS. 25-46.