Phase-noise compensated digital communication receiver and method therefor
First Claim
1. A phase-noise-compensated receiver for digital communication comprising:
- a carrier tracking loop having an input which receives a down-converted digital communication signal and having a phase integrator which generates a phase-conveying signal;
a delay element having an input coupled to said carrier tracking loop and having an output; and
a phase rotator residing outside said carrier tracking loop, having a first input coupled to said delay element output, having a second input coupled to said phase integrator and having an output that provides a signal from which digital communication data are extracted.
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Accused Products
Abstract
A phase-noise compensated digital communication receiver (40, 40'"'"', 40") includes a carrier tracking loop (56) which imposes a transport delay on a carrier tracking loop signal (60) before that signal (60) is fed back upon itself. The carrier tracking loop (56) includes a phase rotator (58) that rotates a down-converted digital communication signal (50) by a phase determined by a phase-conveying signal (72). A carrier tracking loop signal is obtained from the carrier tracking loop and delayed in a delay element (82) by a duration that compensates for the transport delay. A phase rotator (84) then rotates the delayed carrier tracking loop signal through a phase value determined by the phase-conveying signal (72) to obtain an open-loop phase signal (86) from which data are extracted. Different embodiments of the receiver (40, 40'"'"', 40") are provided to accommodate adaptive equalizer (54) issues.
47 Citations
23 Claims
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1. A phase-noise-compensated receiver for digital communication comprising:
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a carrier tracking loop having an input which receives a down-converted digital communication signal and having a phase integrator which generates a phase-conveying signal; a delay element having an input coupled to said carrier tracking loop and having an output; and a phase rotator residing outside said carrier tracking loop, having a first input coupled to said delay element output, having a second input coupled to said phase integrator and having an output that provides a signal from which digital communication data are extracted. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of compensating for phase noise in a digital communication receiver comprising the steps of:
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altering a phase-conveying signal generated by a phase integrator in a carrier tracking loop, said phase-conveying signal being altered to minimize a phase-constellation error signal generated in said carrier tracking loop; obtaining a signal from said carrier tracking loop; delaying said signal extracted from said carrier tracking loop to generate a delayed carrier tracking loop signal, said delayed carrier tracking loop signal being external to said carrier tracking loop; rotating said delayed carrier tracking loop signal in response to said phase-conveying signal to generate an open-loop phase signal; and extracting communicated data from said open-loop phase signal. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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22. A phase-noise-compensated receiver for digital communication comprising:
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an oscillation circuit configured to generate an oscillation signal which exhibits an amount of phase noise; a mixing circuit adapted to receive a communication signal and said oscillation signal, said mixing circuit generating a down-converted digital communication signal that is influenced by said amount of phase noise; a carrier tracking loop having-an input adapted to receive said down-converted digital communication signal, having a phase constellation error detector which detects phase constellation errors in accordance with a modulation order wherein data are communicated at greater than or equal to four bits per unit interval, and having a phase integrator which generates a phase-conveying signal that experiences a group delay plus an implementation delay relative to said down-converted digital communication signal; a delay element having an input coupled to said carrier tracking loop and having an output, said delay element providing a delay of a predetermined duration which substantially compensates for said group delay plus said implementation delay; a phase rotator having a first input coupled to said delay element output, a second input coupled to said phase integrator and an output; and a decoder having an input coupled to said phase rotator output, said decoder providing communicated data. - View Dependent Claims (23)
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Specification