Modified branch metric for decoders and equalizers
AssigneeSibeam, Inc.
InventorsPulakesh Roy, Keang-Po Ho
Life of this patent
Estimating the term…
Abstract
A modified branch metric for decoders and equalizers is described. In one embodiment the branch metric includes determining a set of branch metric values for symbols of a received digital signal, the branch metric values indicating a correlation between symbols obtained using a reduced calculation set, the reduced calculation set being obtained by adding a common term to all of the branch metric values before determining the correlation. The branch metric may be followed by determining path metrics for paths through a decision tree using the branch metric values, and selecting a path and a corresponding symbol sequence in the received digital signal using the path metric values.
Claims20
A decoder for a received digital signal comprising:
- a branch metric unit to determine a correlation between symbols in the digital signal, in part, by adding a common term to all branch metric values before determining the correlation, the common term being based on a combination of input symbols;
- a path metric unit coupled to the branch metric unit to determine metrics for paths through a decision tree;
- and
- a traceback unit coupled to the path metric unit to select a path and a corresponding symbol sequence in the received digital signal based on the path metric determinations.
A method comprising:
- receiving a digital signal in a buffer;
- determining a set of branch metric values for symbols of the received digital signal, the branch metric values indicating a correlation between symbols obtained using a reduced calculation set, the reduced calculation set being obtained by adding a common term to all of the branch metric values before determining the correlation;
- determining path metrics for paths through a decision tree using the branch metric values;
- selecting a path and a corresponding symbol sequence in the received digital signal using the path metric values.
A machine-readable to store a set of instructions that when executed by a processor cause the processor to perform operations comprising:
- determining a set of branch metric values for symbols of a received digital signal, the branch metric values indicating a correlation between symbols obtained using a reduced calculation set, the reduced calculation set being obtained by adding a common term to all of the branch metric values before determining the correlation;
- determining path metrics for paths through a decision tree using the branch metric values;
- and
- selecting a path and a corresponding symbol sequence in the received digital signal using the path metric values.
A method comprising:
- determining branch metric values for possible correlations of an encoded input and corresponding output by multiplying each possible input with each possible output at each stage of an encoder;
- determining path metrics for paths through a decision tree using the branch metric values;
- and
- selecting a path and a corresponding symbol sequence in the received digital signal using the path metric values.
Dependencies are inferred from the claim text.