Multi-code probabilistic signal shaping using frequency-division multiplexing

Patent metadata

Field	Value
Publication number	US-10523400-B2
Application number	US-201715817537-A
Country	US
Kind code	B2
Filing date	Nov 20, 2017
Priority date	Nov 20, 2017
Publication date	Dec 31, 2019
Grant date	Dec 31, 2019

Abstract

An FDM communication system in which encoding/decoding settings for different sets of tones are specified using index values assigned to different sets of tones by selecting suitable respective values from a fixed set of index values. Each of the specified index values causes the corresponding digital signal processor to use a respective predefined pair of encoding or decoding settings that includes a respective predefined constellation and a respective predefined shaping code. In some embodiments, the used shaping codes are configured to operate as block codes, with the block sizes being selected such that a multi-code frame generated using multiple shaping codes can be matched to exactly one DMT symbol or to a desired number of whole DMT symbols.

First claim

What is claimed is:

1. An apparatus comprising a data transmitter that comprises an electrical analog front end, a digital signal processor, and an electronic controller, the digital signal processor including a shaping encoder and a constellation mapper, the electronic controller being configured to:
interpret two or more different index values, each of the two or more different index values being assigned to a different respective set of tones configurable to carry data; and
cause the shaping encoder and the constellation mapper to use, for each of the two or more different index values, a respective predefined pair of settings to generate constellation symbols encoded with the data for transmission on the different respective set of tones, the predefined pair including a respective predefined constellation and a respective predefined shaping code; and
wherein the digital signal processor is configured to drive the analog front end to cause a modulated electrical signal generated by the analog front end to carry the constellation symbols.

2. The apparatus of claim 1 ,
wherein the two or more different index values are selectable from a fixed set of different index values, the fixed set including at least two different index values; and
wherein, for any two different index values from the fixed set, two respective predefined pairs of settings differ from one another either in the respective predefined constellations or in the respective predefined shaping codes, or in both the respective predefined constellations and the respective predefined shaping codes.

3. The apparatus of claim 1 , wherein the data transmitter is configured to receive a control message from a corresponding data receiver or from an electronic management entity, the control message having specified therein the two or more different index values.

4. The apparatus of claim 1 , wherein the data transmitter is a part of a modem or is a part of a service distribution unit.

5. The apparatus of claim 1 , wherein the electronic controller comprises a memory having stored therein a look-up table, the look-up table having specified therein a respective predefined constellation and a respective predefined shaping code for each index value of a fixed set of different index values, the fixed set including at least two different index values.

6. The apparatus of claim 5 , wherein the look-up table further has specified therein a respective partition coefficient for each index value of the fixed set of different index values, the partition coefficient specifying a ratio of a first bit-rate and a second bit-rate, the first bit-rate being a bit-rate at which source bits are to be supplied for being encoded in sign bits of the constellation symbols of the respective predefined constellation, and the second bit-rate being a bit-rate at which source bits are to be supplied for being encoded in amplitudes of the constellation symbols of the respective predefined constellation.

7. The apparatus of claim 1 , wherein the electronic controller is further configured to generate one or more corresponding control signals for the digital signal processor using a tone-order sequence, the tone-order sequence having specified therein an order in which constellation symbols corresponding to different tones are to be generated by the digital signal processor.

8. The apparatus of claim 7 , wherein the data transmitter is configured to receive a control message from a corresponding data receiver or from an electronic management entity, the control message having specified therein the tone-order sequence.

9. An apparatus comprising a data receiver that comprises an electrical analog front end, a digital signal processor, and an electronic controller, the digital signal processor including a constellation demapper and a shaping decoder and being configured to process a stream of values representing an electrical signal outputted by the electrical analog front end in response to a received frequency-division-multiplexed input signal, the electronic controller being configured to:
interpret two or more different index values, each of the two or more different index values being assigned to a different respective set of tones configurable to carry data; and
cause the constellation demapper and the shaping decoder to use, for each of the two or more index values, a respective predefined pair of settings to demap and decode a respective portion of the stream of values, the predefined pair including a respective predefined constellation and a respective predefined shaping code; and
wherein the digital signal processor is configured to process the stream of values to recover the data.

10. The apparatus of claim 9 ,
wherein the two or more different index values are selectable from a fixed set of different index values, the fixed set including at least two different index values; and
wherein, for any two different index values from the fixed set, two respective predefined pairs of settings differ from one another either in the respective predefined constellations or in the respective predefined shaping codes, or in both the respective predefined constellations and the respective predefined shaping codes.

11. The apparatus of claim 10 , wherein the data receiver is configured to:
obtain frequency-dependent signal-to-noise ratio (SNR) information corresponding to the received input signal; and
assign the two or more different index values to the respective different sets of tones using the frequency-dependent SNR information.

12. The apparatus of claim 9 , wherein the data receiver is configured to send a control message to a corresponding data transmitter or to an electronic management entity, the control message having specified therein the two or more different index values.

13. The apparatus of claim 9 , wherein the data receiver is a part of a modem or is a part of a service distribution unit.

14. The apparatus of claim 9 , wherein the electronic controller comprises a memory having stored therein a look-up table, the look-up table having specified therein a respective predefined constellation and a respective predefined shaping code for each index value of a fixed set of different index values, the fixed set including the two or more different index values.

15. The apparatus of claim 9 , wherein the electronic controller is further configured to generate one or more corresponding control signals for the digital signal processor using a tone-order sequence, the tone-order sequence having specified therein an order in which portions of the stream of values corresponding to different tones are to be handled by the digital signal processor.

16. The apparatus of claim 15 , wherein the data receiver is configured to send a control message to a corresponding data transmitter, the control message having specified therein the two or more different index values and the tone-order sequence.

17. A communication method comprising:
configuring an electronic controller to:
interpret two or more different index values, each of the two or more different index values being assigned to a different respective set of tones configurable to carry data; and
cause a shaping encoder and a constellation mapper to use, for each of the two or more different index values, a respective predefined pair of settings to generate constellation symbols encoded with the data for transmission on the different respective set of tones, the predefined pair including a respective predefined constellation and a respective predefined shaping code; and

configuring a digital signal proce

Assignees

• Nokia Technologies Oy

Inventors

• Lefevre Yannick
• Maes Jochen

Classifications

• H04L1/0047

  Decoding adapted to other signal detection operation (in conjunction with sequence estimation or equalization H04L25/03286) · CPC title

• H04L1/0014

  by adapting the source coding · CPC title

• H04L1/0042

  Encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit distortions, jitter, or to improve signal shape (H04L1/0067 takes precedence) · CPC title

• H04L27/3411

  reducing the peak to average power ratio or the mean power of the constellation; Arrangements for increasing the shape gain of a signal set · CPC title

• H04L27/0002

  analog front ends; means for connecting modulators, demodulators or transceivers to a transmission line (duplex arrangements H04L5/143) · CPC title