Hypotheses generation based on multidimensional slicing
A receiver is configured to receive a sample of an inter-symbol correlated (ISC) signal, the sample corresponding to a time instant when phase and/or amplitude of the ISC signal is a result of correlation among a plurality of symbols of a transmitted symbol sequence. The receiver may linearize the sample of the ISC signal. The receiver may calculate a residual signal value based on the linearized sample of the ISC signal. The receiver may generate an estimate of one or more of said plurality of symbols based on a slicing of the residual signal value. The linearization may comprise applying an estimate of an inverse of a non-linear model. The non-linear model may be a model of nonlinearity experienced by the ISC signal in a transmitter from which the ISC signal originated, in a channel through which the ISC signal passed en route to the receiver, and/or in a front-end of the receiver.
1. A system comprising:
a receiver configured to:
receive a sample of an inter-symbol correlated (ISC) signal, said sample corresponding to a time instant when phase and/or amplitude of said ISC signal is a result of correlation among a plurality of symbols of a transmitted symbol sequence;
linearize said sample of said ISC signal;
calculate a residual signal value based on said linearized sample of said ISC signal; and
generate an estimate of one or more of said plurality of symbols based on a slicing of said residual signal value, wherein said slicing is performed via a look-up table.
2. The system of claim 1 , wherein:
said linearization comprises applying an estimate of an inverse of a non-linear model.
3. The system of claim 2 , wherein said non-linear model is a model of nonlinearity experienced by said ISC signal in a transmitter from which said ISC signal originated.
4. The system of claim 2 , wherein said non-linear model is a model of nonlinearity experienced by said ISC signal in a channel through which said ISC signal passed en route to said receiver.
5. The system of claim 2 , wherein said non-linear model is a model of nonlinearity experienced by said ISC signal in a front-end of said receiver.
6. The system of claim 1 , wherein said receiver is configured to, subsequent to said linearization and prior to said generation of said estimate of said one or more of said plurality of symbols, filter said sample of said ISC signal.
7. The system of claim 1 , wherein:
said receiver is configured to generate one or more branch vector hypotheses based on said residual signal value;
each of said one or more branch vector hypotheses comprises a plurality of symbols; and
said receiver is configured to generate said estimate of said one or more of said plurality of symbols based one or more branch vector hypotheses.
8. The system of claim 7 , wherein:
a quantity of branch vector hypotheses in said one or more branch vector hypotheses is larger for a sample of said ISC signal corresponding to a residual signal value that is relatively close to a center of a multidimensional partial lattice; and
said quantity of branch vector hypotheses in said one or more branch vector hypotheses is smaller for a sample of said ISC signal corresponding to a residual signal value that is relatively far from said center of said multidimensional partial lattice.
9. The system of claim 7 , wherein a quantity of branch vector hypotheses is determined based on a signal-to-noise ratio.
10. The system of claim 7 , wherein a quantity of said one or more branch vector hypotheses is determined based on an amount of non-linear distortion experienced by said ISC signal.
11. The system of claim 7 , wherein said receiver is configured to generate said one or more branch vector hypotheses based on a minimal Euclidean distance criterion.
12. The system of claim 7 , wherein said receiver is configured to generate said one or more branch vector hypotheses based on a diversity-distance criterion.
13. The system of claim 1 , wherein said estimate of said one or more of said plurality of symbols is a soft-decision.
14. The system of claim 13 , wherein said soft decision is weighted based on said residual signal value.