Estimating phase using test phases and interpolation for modulation formats using multiple sub-carriers

摘要

An optical receiver may receive input signals carried by sub-carriers, and may apply test phases to each input signal. The optical receiver may determine error values, associated with test phases, for each input signal. The optical receiver may calculate updated metric values, associated with the test phases, for a particular input signal, based on a first error value and a second error value. The first error value may be associated with a first sub-carrier, and the second error value may be associated with a second sub-carrier. The optical receiver may compare the updated metric values associated with the particular input signal, and may determine a test phase that represents an estimated phase, associated with the particular input signal, based on the comparison. The optical receiver may determine a phase estimate value based on the test phase, and may provide the phase estimate value to modify the particular input signal.

主权项

1. An optical receiver, comprising:
a digital signal processor configured to:
receive a plurality of input signals carried by a respective plurality of sub-carriers;apply a plurality of test phases to each input signal of the plurality of input signals;determine a plurality of error values, respectively associated with the plurality of test phases, for each input signal of the plurality of input signals;selectively combine a first error value, of the plurality of error values and associated with a first signal of the plurality of input signals, and a second error value, of the plurality of error values and associated with a second signal of the plurality of input signals,
the first signal being carried by a first sub-carrier of the plurality of sub-carriers,the second signal being carried by a second sub-carrier of the plurality of sub-carriers,
the second sub-carrier being different from the first sub-carrier;calculate a plurality of updated metric values, respectively associated with the plurality of test phases, for a particular input signal of the plurality of input signals, based on selectively combining the first error value and the second error value;compare the plurality of updated metric values associated with the particular input signal;determine a test phase, of the plurality of test phases, that represents an estimated phase, associated with the particular input signal, based on comparing the plurality of updated metric values;determine a phase estimate value based on the test phase; andprovide the phase estimate value to modify the particular input signal.