US 11,456,910 B1 · Carrier-phase recovery system and method

Abstract

A carrier-phase recovery method includes: (i) applying a first carrier-phase recovery algorithm to complex-valued symbols of a signal received by a product detector, yielding coarse phase-estimates, the signal being modulated per an M-QAM scheme; (ii) modelling the coarse phase-estimates as a weighted sum of M probability-density functions of an M-component mixture model; (iii) optimizing the M probability-density functions with an expectation-maximization algorithm to yield M optimized probability-density functions; (iv) mapping, based on the M optimized probability-density functions, the coarse phase-estimates to one of M symbols corresponding to the QAM scheme, each coarse phase-estimate mapped to a same symbol belonging to a same one of M clusters; (v) applying a second carrier-phase recovery algorithm to each of the M clusters to generate refined phase-estimates each corresponding to a respective coarse phase-estimate; and (vi) mapping, based on the M optimized probability-density functions, each refined phase-estimate to one of the M symbols.

Claims24

Dependent claims

A carrier-phase recovery method comprising:

applying a first carrier-phase recovery algorithm to a plurality of complex-valued symbols of a signal received by a product detector to yield a plurality of coarse phase-estimates;
modelling the plurality of coarse phase-estimates as a weighted sum of a plurality of probability density functions;
optimizing parameters of each of the plurality of probability density functions with an expectation-maximization algorithm to yield a plurality of optimized probability density functions;
mapping, based on the plurality of optimized probability density functions, each of the plurality of coarse phase-estimates to one of a plurality of constellation symbols, each of the plurality of coarse phase-estimates mapped to a same constellation symbol belonging to a same one of a plurality of clusters;
applying a second carrier-phase recovery algorithm to each of the plurality of clusters to generate a plurality of refined phase-estimates each corresponding to a respective one of the plurality of coarse phase-estimates;
and
mapping, based on the plurality of optimized probability density functions, each of the plurality of refined phase-estimates to one of the plurality of constellation symbols.

4 more elements

A carrier-phase recovery system:

a processor;
and
memory adapted to store a plurality of complex-valued symbols of a signal and storing non-transitory computer-readable instructions that, when executed by the processor, control the processor to:
apply a first carrier-phase recovery algorithm to the plurality of complex-valued symbols to yield a plurality of coarse phase-estimates;
model the plurality of coarse phase-estimates as a weighted sum of a plurality of probability density functions;
optimize parameters of each of the plurality of probability density functions with an expectation-maximization algorithm to yield a plurality of optimized probability density functions;
map, based on the plurality of optimized probability density functions, each of the plurality of coarse phase-estimates to one of a plurality of constellation symbols, each of the plurality of coarse phase-estimates mapped to a same constellation symbol belonging to a same one of a plurality of clusters;
apply a second carrier-phase recovery algorithm to each of the plurality of clusters to generate a plurality of refined phase-estimates each corresponding to a respective one of the plurality of coarse phase-estimates;
and
map, based on the plurality of optimized probability density functions, each of the plurality of refined phase-estimates to one of the plurality of constellation symbols.

7 more elements

Dependencies are inferred from the claim text.

Carrier-phase recovery system and method

Life of this patent

Carrier-phase recovery system and method

Life of this patent

Abstract

Claims24