Abstract: An apparatus and method for transmitting information bits via an optical communication system, the apparatus including a distribution matcher (DM) configured to receive information bits and to generate shaped symbols relating to the information bits; a pre-deinterleaver (PDI) coupled to the DM and configured to apply a perturbation function q(n) to the shaped symbols to produce pre-deinterleaved symbols; an error reduction processor (ERP) coupled to the PDI and configured to receive computer instructions which, when executed, prompt the ERP to produce error reduction symbols from the pre-deinterleaved symbols, the error reduction symbols being perturbed from the pre-deinterleaved symbols by a perturbation function p(n), q(n) being an inverse of p(n); and a modulator coupled to the ERP and configured to convert the error reduction symbols into optical signals configured for transmission via an optical communication system.

Abstract: Systems and methods for creating and using a first and second group of training sequences in a training-aided single-carrier frequency domain equalization system. The first group of training sequences are conventional training sequences and the second group of training sequences are 90°-rotated versions of the first group of training sequences.

Abstract: Systems and methods for creating and using a first and second group of training sequences in a training-aided single-carrier frequency domain equalization system. The first group of training sequences are conventional training sequences and the second group of training sequences are 90°-rotated versions of the first group of training sequences.

Abstract: An apparatus comprising a receiver configured to receive a super-symbol comprising a first modulation symbol and a second modulation symbol, wherein the first modulation symbol comprises a first modulation format, and wherein the second modulation symbol comprises a second modulation format, and a processor coupled to the receiver and configured to select, for the first modulation symbol, a first nearest candidate symbol from a first set of candidate symbols associated with the first modulation format, select, for the second modulation symbol, a second nearest candidate symbol independent of the first nearest candidate symbol from a second set of candidate symbols associated with the second modulation format, and determine a soft decision value for a first hit in the super-symbol according to the first nearest candidate symbol and the second nearest candidate symbol.

Abstract: An apparatus comprising a receiver configured to receive a super-symbol comprising a first modulation symbol and a second modulation symbol, wherein the first modulation symbol comprises a first modulation format, and wherein the second modulation symbol comprises a second modulation format, and a processor coupled to the receiver and configured to select, for the first modulation symbol, a first nearest candidate symbol from a first set of candidate symbols associated with the first modulation format, select, for the second modulation symbol, a second nearest candidate symbol independent of the first nearest candidate symbol from a second set of candidate symbols associated with the second modulation format, and determine a soft decision value for a first hit in the super-symbol according to the first nearest candidate symbol and the second nearest candidate symbol.

Abstract: A method for reducing link fiber nonlinearities executed by a processor. The method includes decomposing a high order quadrature amplitude modulation (QAM) input into a plurality of sub-components. The method includes applying a plurality of logical operations to the plurality of sub-components. The method includes determining a non-linear compensation term based on the applying the plurality of logical operations to the plurality of sub-components.