Blind coherent combiner and method using coupled phase-lock loops
AssigneeLockheed Martin Corporation
InventorsGreg Steele, Eric Fain
Life of this patent
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Abstract
Coherent combining apparatus and methods that do not require training to adapt combining weights. The approach employed in the present invention uses phase-lock loops to demodulate input signals. The phase-lock loops are coupled so that their outputs are phase coherent. The outputs of the phase-lock loops are summed to obtain a coherent combining of the input signals. Exemplary embodiments of the present invention comprise two or more phase-lock loops having signal inputs and I and Q data outputs. A combiner sums the I and Q data output by the two or more phase-lock loops. A common decision circuit feeds back the summed output of the combiner to the two or more phase-lock loops and generates phase coherent output signals.
Claims5
Apparatus comprising:
- first and second phase-lock loops having signal inputs and I and Q data outputs;
- a combiner for summing the I and Q data output by the first and second phaselock loops;
- and
- a common decision circuit,that feeds back the summed output of the combiner to each phase-lock loop and that outputs phase coherent output signals from the apparatus.
Apparatus comprising:
- two or more phase-lock loops having signal inputs and I and Q data outputs;
- a combiner for summing the I and Q data output by the two or more phase-lock loops;
- and
- a common decision circuit 13 that feeds back the summed output of the combiner to the two or more phase-lock loops and that outputs phase coherent output signals from the apparatus.
A method for coupling two or more phase-lock loops that each output I and Q data to produce a phase coherent output signal, comprising the steps of:
- summing the I and Q data output by the two or more phase-lock loops;
- processing the summed I and Q data using a common decision circuit to generate a phase coherent output signal;
- and
- feeding back the summed I and Q data to the two or more phase-lock loops.
Dependencies are inferred from the claim text.