Phase noise mitigation for wireless communications
First Claim
1. A method for reducing phase noise in a communication receiver, the method comprising:
- receiving a first sequence of input values, each input value comprising an unknown data symbol corrupted by phase noise;
determining a first sequence of data symbols from the first sequence of input values;
determining a sequence of raw phase noise values from both the first sequence of input values and the first sequence of data symbols;
filtering the sequence of raw phase noise values to provide a first sequence of filtered phase noise values; and
compensating the first sequence of input values using the first sequence of filtered phase noise values to provide a sequence of compensated input values;
for one or more iterations until a termination condition is met, performing the elements;
determining a second sequence of data symbols from the sequence of compensated input values;
determining a new sequence of raw phase noise values from both the sequence of compensated input values and the second sequence of data symbols;
filtering the new sequence of raw phase noise values to provide a second sequence of filtered phase noise values; and
compensating the first sequence of input values using the second sequence of filtered phase noise values to update the sequence of compensated input values; and
outputting the updated sequence of compensated input values.
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Accused Products
Abstract
A method and apparatus for tracking and mitigating phase noise in a communication receiver are disclosed. The phase noise tracking and mitigation apparatus operates in a recursive manner and includes a quantizer for determining data symbols from noise-compensated input values, a phase noise estimator for determining raw phase noise values from the data symbols and a first sequence of uncompensated input values, an error concealment module for removing unreliable samples from the raw phase noise values, a filter operable to filter the raw phase noise values to produce filtered phase noise values, and a phase-noise compensator for determining noise-compensated output values dependent upon the filtered phase noise values and the first sequence of uncompensated input values. Filter coefficients, and initial noise-compensated input values are determined from one or more second sequences of uncompensated input values corresponding to known symbols corrupted by phase noise.
34 Citations
18 Claims
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1. A method for reducing phase noise in a communication receiver, the method comprising:
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receiving a first sequence of input values, each input value comprising an unknown data symbol corrupted by phase noise; determining a first sequence of data symbols from the first sequence of input values; determining a sequence of raw phase noise values from both the first sequence of input values and the first sequence of data symbols; filtering the sequence of raw phase noise values to provide a first sequence of filtered phase noise values; and compensating the first sequence of input values using the first sequence of filtered phase noise values to provide a sequence of compensated input values; for one or more iterations until a termination condition is met, performing the elements; determining a second sequence of data symbols from the sequence of compensated input values; determining a new sequence of raw phase noise values from both the sequence of compensated input values and the second sequence of data symbols; filtering the new sequence of raw phase noise values to provide a second sequence of filtered phase noise values; and compensating the first sequence of input values using the second sequence of filtered phase noise values to update the sequence of compensated input values; and outputting the updated sequence of compensated input values. - View Dependent Claims (2, 3, 4, 5)
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6. A method for reducing phase noise in a communication receiver, the method comprising:
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receiving a first sequence of input values, each input value comprising an unknown data symbol corrupted by phase noise; for one or more iterations until a termination condition is met, performing the elements; determining a sequence of data symbols from the first sequence of input values; determining a sequence of raw phase noise values from both the first sequence of input values and the sequence of data symbols; filtering the sequence of raw phase noise values to provide a sequence of filtered phase noise values; and compensating the first sequence of input values using the sequence of filtered phase noise values to provide a sequence of compensated input values; and outputting the sequence of compensated input values, the method further comprising; receiving a second sequence of input values, each input value comprising a known data symbol corrupted by phase noise; and determining coefficients of the prediction filter dependent upon the second sequence of input values and the known data symbols, where the filtering the sequence of raw phase noise values comprises filtering the sequence of raw phase noise values through a prediction filter.
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7. A method for reducing phase noise in a communication receiver, the method comprising:
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receiving a first sequence of input values, each input value comprising an unknown data symbol corrupted by phase noise; for one or more iterations until a termination condition is met, performing the elements; determining a sequence of data symbols from the first sequence of input values; determining a sequence of raw phase noise values from both the first sequence of input values and the sequence of data symbols; filtering the sequence of raw phase noise values to provide a sequence of filtered phase noise values; and compensating the first sequence of input values using the sequence of filtered phase noise values to provide a sequence of compensated input values; and outputting the sequence of compensated input values, where determining the sequence of raw phase noise values from the first sequence of input values and the sequence of data symbols comprises; dividing an input value of the first sequence of input values by a corresponding data symbol of the sequence of data symbols to provide a complex phasor. - View Dependent Claims (8, 9)
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10. A communication receiver having a phase noise tracking and mitigation circuit comprising:
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a quantizer operable to determine data symbols from noise-compensated input values; a phase noise estimator, operable to determine raw phase noise values from the data symbols and a first sequence of uncompensated input values, where a raw phase noise value is determined as a ratio of an uncompensated input value of the sequence of uncompensated input values to a corresponding data symbol; a filter operable to filter the raw phase noise values to produce filtered phase noise values; and a phase-noise compensator, operable to determine noise-compensated output values dependent upon the filtered phase noise values and the first sequence of uncompensated input values. - View Dependent Claims (11, 12, 13, 14)
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15. A communication receiver having a phase noise tracking and mitigation circuit comprising:
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a quantizer operable to determine data symbols from noise-compensated input values; a phase noise estimator, operable to determine raw phase noise values from the data symbols and a first sequence of uncompensated input values; a filter operable to filter the raw phase noise values to produce filtered phase noise values; and a phase-noise compensator, operable to determine noise-compensated output values dependent upon the filtered phase noise values and the first sequence of uncompensated input values, the communication receiver further comprising; an initial phase noise estimator, operable to provide initial phase noise values in response to; a second sequence of input values corresponding to known symbols, the second sequence received before the first sequence, and a third sequence of input values corresponding to known symbols, the third sequence received after the first sequence, the initial phase noise estimator operable to determine an interpolation between phase noise values determined from the second sequence and phase noise values determined from the third sequence. - View Dependent Claims (16, 17, 18)
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Specification