US 12,483,352 B2Granted

Probabilistic constellation shaping of multi-dimensional symbols for improved tolerance to nonlinear impairments

AssigneeCiena Corporation

InventorsHamid Ebrahimzad, Michael Reimer, Vladimir S. Grigoryan, Shahab Oveis Gharan

Life of this patent

Estimating the term…

Loading patent…

Abstract

An optical transmitter device includes a digital signal processor (DSP) having digital hardware. The DSP is operative to generate shaped bits from a first set of information bits, and to apply a systematic forward error correction (FEC) scheme to encode the shaped bits and a second set of information bits, where the first set of information bits and the second set of information bits are disjoint sets. Unshaped bits and the shaped bits are mapped to selected symbols or are used to select symbols from one or more constellations. The selected symbols are mapped to physical dimensions. Each unshaped bit is either one of the second set of information bits or one of multiple parity bits resulting from the FEC encoding. In this manner, a target spectral efficiency is achieved.

Claims20

Dependent claims

An optical transmitter device comprising:

a digital signal processor (DSP) comprising digital hardware, the DSP operative
to generate shaped bits from a first set of information bits;
to apply a systematic forward error correction (FEC) scheme to encode the shaped bits and a second set of information bits, where the first set of information bits and the second set of information bits are disjoint sets;
and
for multiple groups, each group consisting of 6 unshaped bits and one shaped bit,
to select one of two 8 phase shift keying (8PSK) constellations based on a value of the shaped bit, where all symbols of one of the two 8PSK constellations have an amplitude A, all symbols of the other of the two 8PSK constellations have an amplitude B, A and B are real positive numbers, B<A, and a sum of squares of the amplitudes A2+B2 is equal to 1 or differs slightly from 1,
to use the 6 unshaped bits to select a first symbol from a first of the two 8PSK constellations and a second symbol from a second of the two 8PSK constellations;
where the first of the two 8PSK constellations is selected, to map the first symbol to two physical dimensions of an optical carrier component that is polarized in a first polarization and to map the second symbol to two physical dimensions of an optical carrier component that is polarized in a second polarization that is orthogonal to the first polarization;
and
where the second of the two 8PSK constellations is selected, to map the second symbol to the two physical dimensions of the optical carrier component that is polarized in the first polarization and to map the first symbol to the two physical dimensions of the optical carrier component that is polarized in the second polarization,
wherein each of the 6 unshaped bits is either one of the second set of information bits or one of multiple parity bits resulting from the FEC encoding.

8 more elements

A method comprising:

generating shaped bits from a first set of information bits;
applying a systematic forward error correction (FEC) scheme to encode the shaped bits and a second set of information bits, where the first set of information bits and the second set of information bits are disjoint sets;
and
for multiple groups, each group consisting of 6 unshaped bits and one shaped bit,
selecting one of two 8 phase shift keying (8PSK) constellations based on a value of the shaped bit, where all symbols of one of the two 8PSK constellations have an amplitude A, all symbols of the other of the two 8PSK constellations have an amplitude B, A and B are real positive numbers, B<A, and a sum of squares of the amplitudes A2+B2 is equal to 1 or differs slightly from 1,
using the 6 unshaped bits to select a first symbol from a first of the two 8PSK constellations and a second symbol from a second of the two 8PSK constellations;
where the first of the two 8PSK constellations is selected, mapping the first symbol to two physical dimensions of an optical carrier component that is polarized in a first polarization and mapping the second symbol to two physical dimensions of an optical carrier component that is polarized in a second polarization that is orthogonal to the first polarization;
and
where the second of the two 8PSK constellations is selected, mapping the second symbol to the two physical dimensions of the optical carrier component that is polarized in the first polarization and mapping the first symbol to the two physical dimensions of the optical carrier component that is polarized in the second polarization,
wherein each of the 6 unshaped bits is either one of the second set of information bits or one of multiple parity bits resulting from the FEC encoding.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/484,700Filed 11 Oct 2023 · continuation
Priority: 12 Oct 2018
Published: US 2024/0048270 A18 Feb 2024
Granted: 25 Nov 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification19 codes

H04L 1/0042
Arrangements at the transmitter end: encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit…
H04L 27/34
Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26:…
H03M 13/11
Using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits: using multiple parity bits
H04B 10/556
Phase or frequency modulation: digital modulation, e.g. differential phase shift keying [DPSK] or frequency shift keying [FSK]

Family

Application62/744,943Us provisional application · filed 12 Oct 2018
PCT/IB2019/058669Parent of this continuation · filed 11 Oct 2019
Application16/599,157Parent of this continuation · filed 11 Oct 2019
US 10,848,269 B2Parent of this continuation · filed 24 Nov 2020
US 2024/0048270 A1Pre-grant publication · published 8 Feb 2024
Application17/284,573Parent of this continuation
US 11,831,431 B2Parent of this continuation
US 2020/0119840 A1Published application
US 2022/0069919 A1Published application
US 12,483,352 B2This patent

From the US filing history. Foreign family members aren’t listed.