Hierarchical and adaptive multi-carrier digital modulation and demodulation

Patent metadata

Field	Value
Publication number	US-9438394-B2
Application number	US-201214350388-A
Country	US
Kind code	B2
Filing date	Oct 9, 2012
Priority date	Oct 25, 2011
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

In an embodiment the method includes, at a transmit side, grouping carriers into carrier groups, and selecting a group constellation diagram for modulation of the carriers of a given carrier group. The selected group constellation diagram is built as a hierarchical sum of I super-imposed constellations vectors having predefined decreasing powers with the P strongest and the Q weakest constellation vectors being omitted. The carriers of the carrier group are modulated by means of the selected group constellation diagram, and P and/or Q parameters per carrier group and per multi-carrier data symbol are adjusted.

First claim

The invention claimed is:

1. A method for encoding a binary stream into multi-carrier data symbols, the method comprising:
grouping a plurality of carriers into a plurality of carrier groups, each of the plurality of carrier groups including a separate selection of the plurality of carriers; and
iteratively performing, for each carrier group of the plurality of carrier groups,
for a given carrier group including N carriers, selecting a group constellation diagram for modulation of the N carriers of the given carrier group, the selected group constellation diagram including constellation points defined as respective hierarchical sums of I super-imposed constellation vectors having predefined decreasing powers with the P strongest constellation vectors and the Q weakest constellation vectors being omitted, P being a positive integer parameter, Q being a positive integer parameter, and I being a positive integer value that determines a maximum constellation size; and
mapping N binary words for the respective N carriers of the given carrier group onto N respective constellation points of the selected group constellation diagram, with the P and Q parameters remaining unchanged for the given carrier group and being adjusted to their optimal value per carrier group and per multi-carrier data symbol.

2. The method according to claim 1 , wherein the P parameter is adjusted according to a power budget criterion.

3. The method according to claim 1 , wherein the Q parameter is adjusted according to a noise criterion.

4. The method according to claim 1 , wherein the Q parameter is adjusted according to acknowledgment information from a peer receiver.

5. The method according to claim 1 , wherein at least one parameter of the P and Q parameters is adjusted according to a Quality of Service QoS criterion.

6. The method according to claim 1 , wherein at least one parameter of the P and Q parameters is adjusted according to outgoing traffic demand.

7. The method according to claim 1 , wherein the I super-imposed constellation vectors are 4-QAM vectors.

8. The method according to claim 1 , wherein carrier transmit powers are individually shaped in accordance with a transmit power spectral mask and/or are individually fine-tuned according to respective relative carrier gains.

9. The method according to claim 1 , further comprising:
scrambling the binary stream prior to mapping the N binary words onto the N respective constellation points.

10. A method for blindly decoding a binary stream from multi-carrier data symbols, and comprising, at a receive side:
grouping a plurality of carriers into a plurality of carrier groups, each of the plurality of carrier groups including a separate selection of the plurality of carriers;
iteratively performing, for each carrier group of the plurality of carrier groups,
for a given carrier group including N carriers, selecting a group constellation diagram for demodulation of the N carriers of the given carrier group by statistical characterization of the N carriers or part thereof, the selected group constellation diagram including constellation points defined as respective hierarchical sums of I super-imposed constellation vectors having decreasing powers with the P strongest constellation vectors and the Q weakest constellation vectors being omitted, P being a positive integer parameter, Q being a positive integer parameter, I being a positive integer value that determines a maximum constellation size; and
de-mapping the respective N carriers of the given carrier group into N respective binary words based on the selected group constellation diagram, with the P and Q parameters remaining unchanged for the given carrier group and being re-evaluated per carrier group and per multi-carrier data symbol.

11. The method according to claim 10 , further comprising:
evaluating at least one parameter of the P and Q parameters by statistical characterization of at least one of a power distribution or amplitude distribution of at least a portion of the N carriers.

12. The method according to claims 10 , wherein the I super-imposed constellation vectors are 4-QAM vectors.

13. A transmitter comprising:
a processor configured to,
group a plurality of carriers into a plurality of carrier groups, each of the plurality of carrier groups including a separate selection of the plurality of carriers;
iteratively perform, for each carrier group of the plurality of carrier groups,
for a given carrier group including N carriers, select a group constellation diagram for modulation of the N carriers of the given carrier group, the selected group constellation diagram including constellation points defined as respective hierarchical sums of I super-imposed constellation vectors having decreasing powers with the P strongest constellation vectors and the Q weakest constellation vectors being omitted, P being a positive integer parameter, Q being a positive integer parameter, and I being a positive integer value that determines a maximum constellation size; and
map N binary words for respective N carriers of the given carrier group onto N respective constellation points of the selected constellation diagram, with the P and Q parameters remaining unchanged for the given carrier group and being adjusted to their optimal value per carrier group and per multi-carrier data symbol.

14. A receiver comprising:
a processor configured to,
group a plurality of carriers into a plurality of carrier groups, each of the plurality of carrier groups including a separate selection of the plurality of carriers;
iteratively perform, for each carrier group of the plurality of carrier groups,
for a given carrier group including N carriers, select a group constellation diagram for demodulation of the N carriers of the given carrier group by statistical characterization of the N carriers or part thereof, the selected group constellation diagram including constellation points defined as respective hierarchical sums of I super-imposed constellation vectors having decreasing powers with the P strongest constellation vectors and the Q weakest constellation vectors being omitted, P being a positive integer parameter, Q being a positive integer parameter, I being a positive integer value that determines a maximum constellation size; and
de-map the respective N carriers of the given carrier group into N respective binary words based on the selected group constellation diagram, with the P and Q parameters remaining unchanged for the given carrier group and being re-evaluated per carrier group and per multi-carrier data symbol.

Assignees

• Alcatel Lucent
• Alcatel Lucent

Inventors

• Vanderhaegen Dirk
• Van Bruyssel Danny
• Maes Jochen
• De Schepper Koen
• Timmers Michael

Classifications

• Y02B60/31

  Cross-Sectional Technologies · mapped topic

• H04L27/3488

  Multiresolution systems · CPC title

• H04L1/0003

  by switching between different modulation schemes · CPC title

• H04L5/0046 Primary

  Determination of the number of bits transmitted on different sub-channels · CPC title

• H04L27/34 Primary

  Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems · CPC title