Digital phase detector
First Claim
Patent Images
1. A digital phase detector which periodically detects the phase angle θ
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k of a carrier signal in which data are encoded as discrete phase changes, said detector comprising;
means responsive to said carrier signal for separating said carrier signal into its in-phase and quadrature-phase signal components Ro cos θ
(t) and Ro sin θ
(t);
means for converting said signal components Ro cos θ
(t) and Ro sin θ
(t) at predetermined modulation intervals, into encoded binary signals Ro cos θ
hd k and Ro sin θ
k ;
means responsive to said binary signals for forming said phase angle θ
k that is proportional to the encoded data, said forming means comprising;
dividing means responsive to said binary signals Ro cos θ
k and Ro sin θ
k for digitally forming the quotient Ψ
of said binary signals, such that |Ψ
|≦
1;
data look-up means for digitally forming a reference angle signal Φ
such that Φ
= tan -1 Ψ
; and
logic means for modifying the reference signal Φ
to be the phase angle θ
k, said modification being determined by said binary signals Ro cos θ
k and Ro sin θ
k.
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Abstract
A digital phase detector which periodically detects the phase angle θk of a carrier signal in which data are encoded as discrete phase changes. A coherent or differential phase-modulated carrier signal is split into its in-phase and quadrature phase components Ro Sinθ(t) and Ro Cosθ (t). Each signal component is sampled at a predetermined modulation interval and converted into a digital word having the form Ro Cosθk and Ro Sinθk. In one configuration, the two signal components are applied to a digital divider network which forms the quotient Ψ of the two digital words such that |Ψ|≦ 1. The quotient Ψis applied to a data look-up ROM, programmed for Tan-1 operation, which forms a digital reference phase angle Φlimited to an angle ≦ 45° is corrected by selection logic to form the desired phase angle θk. Once θk is known for each modulation interval, the encoded data may be readily extracted, since θk is proportional to the encoded data.
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Citations
17 Claims
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1. A digital phase detector which periodically detects the phase angle θ
-
k of a carrier signal in which data are encoded as discrete phase changes, said detector comprising;
means responsive to said carrier signal for separating said carrier signal into its in-phase and quadrature-phase signal components Ro cos θ
(t) and Ro sin θ
(t);means for converting said signal components Ro cos θ
(t) and Ro sin θ
(t) at predetermined modulation intervals, into encoded binary signals Ro cos θ
hd k and Ro sin θ
k ;means responsive to said binary signals for forming said phase angle θ
k that is proportional to the encoded data, said forming means comprising;dividing means responsive to said binary signals Ro cos θ
k and Ro sin θ
k for digitally forming the quotient Ψ
of said binary signals, such that |Ψ
|≦
1;data look-up means for digitally forming a reference angle signal Φ
such that Φ
= tan -1 Ψ
; andlogic means for modifying the reference signal Φ
to be the phase angle θ
k, said modification being determined by said binary signals Ro cos θ
k and Ro sin θ
k. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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k of a carrier signal in which data are encoded as discrete phase changes, said detector comprising;
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9. A digital phase detector which periodically detects the phase angle θ
-
k of a carrier signal in which data are encoded as discrete phase changes, said detector comprising;
means responsive to said carrier signal for separating said carrier signal into its in-phase and quadrature-phase signal components Ro cos θ
(t) and Ro sin θ
(t);means for converting said signal components Ro cos θ
(t) and Ro sin θ
(t) at predetermined modulation intervals into encoded binary signals Ro cos θ
k and Ro sin θ
k ;dividing means responsive to said binary signals Ro cos θ
k and Ro sin θ
k for digitally forming the quotient Ψ
of said binary signals, such that |Ψ
| ≦
1;data look-up means for digitally forming a reference angle signal Φ
such that Φ
= tan -1 Ψ
; andlogic means for modifying the reference signal Φ
to be the phase angle θ
k, said modification being determined by said binary signals Ro cos θ
k and Ro sin θ
k. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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k of a carrier signal in which data are encoded as discrete phase changes, said detector comprising;
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17. A method of phase detection which periodicaly detects the phase angle θ
-
k of a carrier signal in which data are encoded as discrete phase changes, said method comprising the steps of;
splitting said carrier signal into its in-phase and quadrature-phase signal components Ro cos θ
(t) and Ro sin θ
(t);converting said Ro cos θ
(t) and Ro sin θ
(t) at predetermined modulation intervals into encoded binary signals Ro cos θ
k and Ro sin θ
k ;dividing said binary signals Ro cos θ
k and Ro sin θ
k to form the quotient Ψ
such that |Ψ
| ≦
1;digitally translating said quotient Ψ
into a reference angle signal Φ
= tan -1 Ψ
; anddigitally correcting said reference signal Φ
to be the phase angle θ
k, said correction being determined by said binary signals Ro cos θ
k and Ro sin θ
k.
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k of a carrier signal in which data are encoded as discrete phase changes, said method comprising the steps of;
Specification
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Current AssigneeAG Communication Systems Corp. (Nokia Corporation)
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Original AssigneeGTE Automatic Electric Laboratories Incorporated
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InventorsTracey, Robert J., Clark, Thomas E., Violet, Ronald J.
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Primary Examiner(s)Ruggiero, Joseph F.
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Application NumberUS05/516,834Time in Patent Office568 DaysField of Search235/186, 235/189, 235/152, 235/156, 235/164, 325/320, 178/67, 178/68, 328/133, 328/155, 329/104, 329/126, 324/83 D, 444/1US Class Current708/440CPC Class CodesG06F 1/0353 by using symmetrical proper...H04L 27/2338 using sampling H04L27/2331 ...
