Symbol demodulator with error reduction
AssigneeNXP USA, Inc.
InventorsMihai-Ionut Stanciu, Claudio Gustavo Rey
Life of this patent
Estimating the term…
Abstract
A demodulator and method includes a plurality of correlation circuits, a result combining stage, and a time combining stage. The plurality of correlation circuits may be configured to output a plurality of correlation values that indicate a likelihood of whether a pattern of a buffered portion of an input data signal matches a first plurality of target frequency behavior patterns. The plurality of correlation circuits may be further configured to output a plurality of delayed correlation values that indicate a likelihood of whether a pattern of a delayed buffered portion of the input data signal matches a second plurality of target frequency behavior patterns, where both the buffered portion and the delayed buffered portion include a current symbol.
Claims20
A frequency shift keying (FSK) demodulator, comprising:
- a plurality of correlation circuits configured to output a plurality of correlation values that indicate a likelihood of whether a pattern of a buffered portion of an input data signal matches a first plurality of target frequency behavior patterns, and configured to output a plurality of delayed correlation values that indicate a likelihood of whether a pattern of a delayed buffered portion of the input data signal matches a second plurality of target frequency behavior patterns, the buffered portion and the delayed buffered portion including a current symbol;
- a result combining stage coupled to the plurality of correlation circuits, the result combining stage configured to output a set of maximum correlation values based on less than all of the plurality of correlation values and the plurality of delayed correlation values;
- and
- a time combining stage coupled to the result combining stage, the time combining stage configured to combine the set of maximum correlation values to produce a demodulation decision that returns a most likely symbol value for the current symbol.
A method of demodulating, comprising:
- generating a plurality of correlation values that indicate a likelihood of whether a pattern of a buffered portion of an input data signal matches a first plurality of target frequency behavior patterns;
- generating a plurality of delayed correlation values that indicate a likelihood of whether a pattern of a delayed buffered portion of the input data signal matches a second plurality of target frequency behavior patterns, the buffered portion and the delayed buffered portion including a current symbol;
- outputting a set of maximum correlation values based on less than all of the plurality of correlation values and the plurality of delayed correlation values;
- and
- combining the set of maximum correlation values to produce a demodulation decision that returns a most likely symbol value for the current symbol.
A frequency shift keying (FSK) demodulator, comprising:
- a plurality of correlation circuits configured to receive an input data signal spread by a spreading code, each of the plurality of correlation circuits configured to generate a correlation metric and a delayed correlation metric respectively representing a likelihood of a match of a pattern of a buffered portion of the input data signal with a first target frequency behavior pattern and of a pattern of a delayed buffered portion of the input data signal with a second target frequency behavior pattern, the buffered portion and the delayed buffered portion including a current symbol;
- a result combining stage coupled to the plurality of correlation circuits, the result combining stage configured to output a set of maximum correlation values based on less than all of the plurality of correlation values and the plurality of delayed correlation values;
- and
- a time combining stage coupled to the result combining stage, the time combining stage configured to combine the set of maximum correlation values to produce a demodulation decision that returns a most likely symbol value for the current symbol.
Dependencies are inferred from the claim text.