US 12,483,352 B2
Probabilistic constellation shaping of multi-dimensional symbols for improved tolerance to nonlinear impairments
Hamid Ebrahimzad, Ottawa (CA); Michael Reimer, Stittsville (CA); Vladimir S. Grigoryan, Elkridge, MD (US); and Shahab Oveis Gharan, Ottawa (CA)
Assigned to Ciena Corporation, Hanover, MD (US)
Filed by Ciena Corporation, Hanover, MD (US)
Filed on Oct. 11, 2023, as Appl. No. 18/484,700.
Application 18/484,700 is a continuation of application No. 17/284,573, granted, now 11,831,431, previously published as PCT/IB2019/058669, filed on Oct. 11, 2019.
Application 17/284,573 is a continuation of application No. 16/599,157, filed on Oct. 11, 2019, granted, now 10,848,269, issued on Nov. 24, 2020.
Claims priority of provisional application 62/744,943, filed on Oct. 12, 2018.
Prior Publication US 2024/0048270 A1, Feb. 8, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04L 1/00 (2006.01); H03M 13/11 (2006.01); H04B 10/556 (2013.01); H04B 10/58 (2013.01); H04L 27/20 (2006.01)
CPC H04L 1/0042 (2013.01) [H03M 13/11 (2013.01); H04B 10/556 (2013.01); H04B 10/5561 (2013.01); H04B 10/58 (2013.01); H04L 1/0041 (2013.01); H04L 1/0056 (2013.01); H04L 1/0057 (2013.01); H04L 27/20 (2013.01)] 20 Claims
OG exemplary drawing
 
1. 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.