DECISION FEEDBACK EQUALIZER UTILIZING SYMBOL ERROR RATE BIASED ADAPTATION FUNCTION FOR HIGHLY SPECTRALLY EFFICIENT COMMUNICATIONS
One or more embodiments describe a decision feedback equalizer utilizing symbol error rate biased adaptation function for highly spectrally efficient communications. A method may be performed in a decision feedback equalizer (DFE). The method may include determining values of tap coefficients used by the DFE based. The tap coefficients may be determined based on an error signal that is based on an estimated inter-symbol-correlated (ISC) signal. The tap coefficients may be determined based on a set of error vector(s), where each error vector in the set represents a difference between estimated symbols generated in the receiver and expected symbols. Determining the values of the tap coefficients may include using a symbol error rate function that estimates the actual symbol error rate in the receiver, wherein the symbol error rate function receives as input the set of error vector(s).
1 - 20 . (canceled)
21 . A receiver comprising:
an equalizer circuit operable to perform frequency-dependent processing of a received signal; and
circuitry operable to:
determine one or more error vectors that occur most-frequently in said receiver, wherein said one or more error vectors are a subset of all possible error vectors;
calculate a minimum distance based on said one or more error vectors; and
adapt a response of said equalizer based on a determined minimum distance.
22 . The receiver of claim 21 , wherein said adaptation uses a symbol error rate function that includes one or more terms that represent the Euclidian distance of each of said one or more error vectors.
23 . The receiver of claim 22 , wherein, as part of said adaptation, said circuitry is operable to seek a minimum of a symbol error rate function.
24 . The receiver of claim 21 , wherein each of said one or more error vectors represents a difference between estimated symbols generated in the receiver and expected symbols.
25 . The receiver of claim 24 , wherein said expected symbols are predetermined symbols sent by a transmitter.
26 . The receiver of claim 24 , wherein said expected symbols are determined by an error correction unit of said receiver.
27 . The receiver of claim 21 comprising a sequence estimation circuit, wherein said adaptation is based on an output of said sequence estimation circuit.
28 . The receiver of claim 27 comprising nonlinear distortion modeling circuitry operable to generate a model of nonlinear distortion present in said received signal.
29 . The receiver of claim 28 , wherein said circuitry is operable to distort said output of said sequence estimation circuit using said model of nonlinear distortion to generate a control signal which is used for said adaptation.
30 . A method comprising:
in a receiver comprising an equalizer circuit operable to perform frequency-dependent processing of a received signal:
determining, by circuitry of said receiver, one or more error vectors that occur most-frequently in said receiver, wherein said one or more error vectors are a subset of all possible error vectors;
calculating, by said circuitry, a minimum distance based on said one or more error vectors; and
adapting, by said circuitry, a response of said equalizer based on a determined minimum distance.
31 . The method of claim 30 , wherein said adapting uses a symbol error rate function that includes one or more terms that represent the Euclidian distance of each of said one or more error vectors.
32 . The receiver of claim 31 , wherein, as part of said adapting, said circuitry seeks a minimum of a symbol error rate function.
33 . The receiver of claim 31 , wherein each of said one or more error vectors represents a difference between estimated symbols generated in the receiver and expected symbols.
34 . The receiver of claim 33 , wherein said expected symbols are predetermined symbols sent by a transmitter.
35 . The receiver of claim 33 , wherein said expected symbols are determined by an error correction unit of said receiver.
36 . The receiver of claim 30 comprising performing said adapting based on an output of a sequence estimation circuit of said receiver.
37 . The receiver of claim 36 comprising generating, by nonlinear distortion modeling circuitry of said receiver, a model of nonlinear distortion present in said received signal.
38 . The receiver of claim 37 , comprising distorting said output of said sequence estimation circuit using said model of nonlinear distortion to generate a control signal used for said adapting.