Unequally spaced pulse amplitude modulation scheme

Patent metadata

Field	Value
Publication number	US-10212010-B2
Application number	US-201715649433-A
Country	US
Kind code	B2
Filing date	Jul 13, 2017
Priority date	Jul 13, 2017
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

A digital communication technique, implementable in a digital communication system, includes performing a training phase in which the transmitter sends one or more transmissions of pulse amplitude modulation (PAM) signals wherein the PAM signals are modulated using one or more data-to-PAM-symbol mapping schemes, performing a feedback phase in which the transmitter receives a feedback message from a receiver, the feedback message indicative of a change to be made to data-to-PAM-symbol modulation schemes, and implementing a data transmission phase in which data is transmitted using a current PAM symbol mapping scheme based on the feedback message, wherein at least some symbols of the current PAM symbol modulation scheme are unequally spaced with respect to each other.

First claim

What is claimed is what is described and illustrated, including:

1. A method of digital communication, implementable at a transmitter in a digital communication system, comprising:
performing a training phase in which the transmitter sends one or more transmissions of pulse amplitude modulation (PAM) signals wherein the PAM signals are modulated using one or more data-to-PAM-symbol mapping schemes, wherein the one or more data-to-PAM-symbol mapping schemes comprise a set of modulation schemes in which PAM symbols are unequally spaced;
performing a feedback phase in which the transmitter receives a feedback message from a receiver, the feedback message indicative of a change to be made to data-to-PAM-symbol mapping schemes, wherein the feedback message includes receiver-side noise statistics;
deciding, based on the receiver-side noise statistics, a current PAM symbol mapping scheme, wherein the current PAM symbol mapping scheme is selected to have symbol spacing proportional to noise distribution measured at each PAM symbol level; and
implementing a data transmission phase in which data is transmitted using the current PAM symbol mapping scheme based on the feedback message, wherein at least some symbols of the current PAM symbol mapping scheme are unequally spaced with respect to each other.

2. The method of claim 1 , wherein the feedback message identifies one of the set of modulation schemes suitable for data transmission during the data transmission phase.

3. The method of claim 1 , wherein the PAM signals include 4-PAM signals.

4. A method of digital communication, implementable at a transmitter in a digital communication system, comprising:
performing a training phase in which the transmitter sends one or more transmissions of pulse amplitude modulation (PAM) signals wherein the PAM signals are modulated using one or more data-to-PAM-symbol mapping schemes, wherein the one or more data-to-PAM-symbol mapping schemes comprise a set of modulation schemes in which PAM symbols are unequally spaced, wherein a same maximum level and a same minimum amplitude level are used in each data-to-PAM-symbol mapping scheme;
performing a feedback phase in which the transmitter receives a feedback message from a receiver, the feedback message indicative of a change to be made to data-to-PAM-symbol mapping schemes, wherein the feedback message includes receiver-side noise statistics;
deciding, based on the receiver-side noise statistics, a current PAM symbol mapping scheme, wherein the current PAM symbol mapping scheme is selected to have symbol spacing proportional to noise distribution measured at each PAM symbol level; and
implementing a data transmission phase in which data is transmitted using the current PAM symbol mapping scheme based on the feedback message, wherein at least some symbols of the current PAM symbol mapping scheme are unequally spaced with respect to each other.

5. The method of claim 4 , wherein the feedback message identifies one of the set of modulation schemes suitable for data transmission during the data transmission phase.

6. The method of claim 4 , wherein the PAM signals include 4-PAM signals.

7. A method of digital communication, implementable at a receiver in a digital communication system, comprising:
performing a training phase in which the receiver receives one or more transmissions of pulse amplitude modulation (PAM) signals wherein the PAM signals are modulated using one or more data-to-PAM-symbol mapping schemes, wherein the one or more data-to-PAM-symbol mapping schemes comprise a set of modulation schemes in which PAM symbols are unequally spaced;
performing a feedback phase in which the receiver transmits a feedback message to a transmitter, the feedback message indicative of a change to be made to data-to-PAM-symbol mapping schemes, wherein the feedback message includes receiver-side noise statistics;
deciding, based on the receiver-side noise statistics, a current PAM symbol mapping scheme, wherein the current PAM symbol mapping scheme is selected to have symbol spacing proportional to noise distribution measured at each PAM symbol level; and
implementing a data reception phase in which data is received using the current PAM symbol mapping scheme based on the feedback message, wherein at least some symbols of the current PAM symbol mapping scheme are unequally spaced with respect to each other.

8. The method of claim 7 , wherein the feedback message identifies one of the set of modulation schemes suitable for data transmission during a data transmission phase.

9. The method of claim 7 , wherein the PAM signals include 4-PAM signals.

10. A method of digital communication, implementable at a receiver in a digital communication system, comprising:
performing a training phase in which the receiver receives one or more transmissions of pulse amplitude modulation (PAM) signals wherein the PAM signals are modulated using one or more data-to-PAM-symbol mapping schemes, wherein the one or more data-to-PAM-symbol mapping schemes comprise a set of modulation schemes in which PAM symbols are unequally spaced, wherein a same maximum level and a same minimum amplitude level are used in each data-to-PAM-symbol mapping scheme;
performing a feedback phase in which the receiver transmits a feedback message to a transmitter, the feedback message indicative of a change to be made to data-to-PAM-symbol mapping schemes, wherein the feedback message includes receiver-side noise statistics;
deciding, based on the receiver-side noise statistics, a current PAM symbol mapping scheme, wherein the current PAM symbol mapping scheme is selected to have symbol spacing proportional to noise distribution measured at each PAM symbol level; and
implementing a data reception phase in which data is received using the current PAM symbol mapping scheme based on the feedback message, wherein at least some symbols of the current PAM symbol mapping scheme are unequally spaced with respect to each other.

11. The method of claim 10 , wherein the feedback message identifies one of the set of modulation schemes suitable for data transmission during a data transmission phase.

12. The method of claim 10 , wherein the PAM signals include 4-PAM signals.

13. An optical communication apparatus, comprising:
a transmission circuit that is configured to send one or more transmissions of pulse amplitude modulation (PAM) signals during a transmission phase, wherein the PAM signals are modulated using one or more data-to-PAM-symbol mapping schemes, wherein the one or more data-to-PAM-symbol mapping schemes comprise a set of modulation schemes in which PAM symbols are unequally spaced;
a receiver circuit that is configured to receive, during a feedback phase, a feedback message, the feedback message indicative of a change to be made to data-to-PAM-symbol mapping schemes, wherein the feedback message includes receiver-side noise statistics; and
a processor that controls operations of the optical communication apparatus to:
decide, based on the receiver-side noise statistics, a current PAM symbol mapping scheme, wherein the current PAM symbol mapping scheme is selected to have symbol spacing proportional to noise distribution measured at each PAM symbol level, and
transmit data during a data transmission phase using the current PAM symbol mapping scheme based on the feedback message, wherein at least some symbols of the current PAM symbol mapping scheme are unequally spaced with respect to each other.

14. The apparatus of claim 13 , wherein the feedback message identifies one of the set of modulation schemes suitable for data transmission during the data t

Assignees

• Zte Corp

Inventors

• Zhang Junwen
• Yu Jianjun
• Cai Yi
• Shi Jianyang

Classifications

• H04L27/04 Primary

  Modulator circuits; Transmitter circuits · CPC title

• H04L27/06

  Demodulator circuits; Receiver circuits · CPC title

• H03K7/02

  Amplitude modulation, i.e. PAM · CPC title

• H04B10/524

  Pulse modulation · CPC title

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title