Methods and devices for estimating QAM symbol sequences over flat fading channels using multiple offset sequences
AssigneeLucent Technologies Inc.
InventorThomas William Goeddel
Life of this patent
Estimating the term…
Abstract
A sequence of Quadrature Amplitude Modulated (“QAM”) data symbols is received and its' fading process estimated. The estimated fading process is then used to generate estimates of the identity of the symbols themselves. Instead of using the single, received sequence to complete the fading process estimates, multiple offset sequences are used. For a given signal-to-noise ratio, the resulting fading process estimates and data symbol estimates provide for reduced bit error rates.
Claims36
A method for estimating QAM symbol sequences over flat-fading channels comprising:
- separating a first sequence of symbols into second sequences of symbols, each separated sequence being offset from another separated sequence;
- generating an estimate for each of the second sequences using a sequence estimation algorithm;
- generating an estimate of a fading process for each of the second sequences using the respective, estimated sequence of symbols;
- combining the estimates of the fading process from each of the second sequences;
- and
- generating a third, single sequence of estimates of the fading process from the combined sequences.
A device for estimating QAM symbol sequences over flat-fading channels comprising:
- a splitter adapted to split a first sequence of symbols into second sequences of symbols, each separated sequence being offset from another separated sequence;
- estimators adapted to generate estimates for each of the second sequences using a sequence estimation algorithm and further adapted to generate estimates of a fading process for each of the second sequences using the respective, estimated sequence of symbols;
- and
- a combiner adapted to combine the estimates of the fading process from each of the second sequences and further adapted to generate a third, single sequence of estimates of the fading process from the combined sequences.
A device for estimating QAM symbol sequences over flat-fading channels comprising:
- splitting means for splitting a first sequence of symbols into second sequences of symbols, each separated sequence being offset from another separated sequence;
- estimating means for generating estimates for each of the second sequences using a sequence estimation algorithm and for generating estimates of a fading process for each of the second sequences using the respective, estimated sequence of symbols;
- and
- combining means for combining the estimates of the fading process from each of the second sequences and
- for generating a third, single sequence of estimates of the fading process from the combined sequences.
Dependencies are inferred from the claim text.