US5490177A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for determining signal quality
Assignee: Motorola Solutions Inc
•
Filing: 1994-03-23
•
Granted: 1996-02-06
•
Expires: 2014-03-23
Abstract
Abstract A unique method and apparatus determines signal quality and/or bit reliability information for a plurality of phase modulated information symbols. This is accomplished by first detecting the phase of the received phase modulated signal (201). The resulting phase estimate is then compared against the nearest expected phase value to form a phase error signal (202). The phase error signal is then mapped into a symbol quality estimate (205/206), which is then averaged over multiple symbol intervals to form a signal quality indicator (207). Finally, bit reliability information is generated by weighting the in-phase (I) and quadrature (Q) components of the phase estimate by the derived signal quality indicator (209). With such a method and apparatus, signal quality and/or bit reliability information can be determined without the need for signal amplitude information.
Inventors
- 👤 Christopher P. La Rosa
- 👤 Michael J. Carney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:51
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/18; H04L27/22; H04L1/00; H04L1/24
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
105 words
In a receiver that receives a plurality of phase modulated digital symbols, a method for providing signal quality information of the plurality of phase modulated digital symbols, the method comprising the steps of: a) for each phase modulated digital symbol of at least some of the plurality of phase modulated digital symbols, producing a corresponding phase estimate; b) determining a corresponding phase error signal from the phase estimate; c) determining a symbol quality estimation based on the phase error signal; and d) determining the signal quality information of the plurality of phase modulated digital symbols based on a predetermined number of determined symbol quality estimations.
Claim 2
Dependent Claim
105 words
In a receiver that receives a plurality of phase modulated digital symbols, a method for providing signal quality information of the plurality of phase modulated digital symbols, the method comprising the steps of: a) for each phase modulated digital symbol of at least some of the plurality of phase modulated digital symbols, producing a corresponding phase estimate; b) determining a corresponding phase error signal from the phase estimate; c) determining a symbol quality estimation based on the phase error signal; and d) determining the signal quality information of the plurality of phase modulated digital symbols based on a predetermined number of determined symbol quality estimations.
Claim 3
Dependent Claim
26 words
The method for providing signal quality information of claim 1 wherein the step of producing a corresponding phase estimate includes generating a limited intermediate frequency signal.
Claim 4
Dependent Claim
29 words
The method for providing signal quality information of claim 2 wherein the step of producing a corresponding phase estimate includes detecting the phase of the limited intermediate frequency signal.
Claim 5
Dependent Claim
28 words
The method for providing signal quality information of claim 1 wherein said step of determining a phase error signal includes comparing the phase estimate to a predetermined phase.
Claim 6
Dependent Claim
35 words
The method for providing signal quality information of claim 1 wherein said step of determining a symbol quality estimation includes comparing the corresponding phase error signal to a predetermined threshold for the phase error signal.
Claim 7
Dependent Claim
53 words
The method for providing signal quality information of claim 5 wherein the step of determining a symbol quality estimation includes generating a first predetermined value when the phase error signal is greater than the predetermined threshold and generating a second predetermined value when the phase error signal is less than the predetermined threshold.
Claim 8
Dependent Claim
27 words
The method for providing signal quality information of claim 1 wherein said step of determining signal quality information includes averaging the predetermined number of symbol quality estimations.
Claim 9
Dependent Claim
24 words
The method for providing signal quality information of claim 1 further including a step generating bit reliability information based upon the signal quality information.
Claim 10
Dependent Claim
34 words
The method for providing signal quality information of claim 8 wherein the step of generating bit reliability information includes generating a plurality of signals based upon the signal quality information and the phase estimate.
Claim 11
Dependent Claim
46 words
The method for providing signal quality information of claim 8 wherein the step of generating bit quality information includes generating an in-phase component and a quadrature component, both the in-phase component and the quadrature component being based upon the signal quality information and the phase estimate.
Claim 12
Dependent Claim
35 words
The method for providing signal quality information of claim 1 wherein said step of producing a corresponding phase estimate includes generating a corresponding phase estimate for each of said plurality of phase modulated digital symbols.
Claim 13
Dependent Claim
111 words
In a receiver that receives a plurality of phase modulated digital symbols, a method for generating bit reliability information of the plurality of phase modulated digital symbols, each phase modulated digital symbol having associated therewith phase information, the method comprising the steps of: a) for each digital symbol of at least some of the plurality of phase modulated digital symbols, determining a symbol quality estimation based on the associated phase information; b) determining signal quality information of the plurality of phase modulated digital symbols based on a predetermined number of determining symbol quality estimations; and c) said generating bit reliability information based upon the signal quality information and the phase information.
Claim 14
Dependent Claim
111 words
In a receiver that receives a plurality of phase modulated digital symbols, a method for generating bit reliability information of the plurality of phase modulated digital symbols, each phase modulated digital symbol having associated therewith phase information, the method comprising the steps of: a) for each digital symbol of at least some of the plurality of phase modulated digital symbols, determining a symbol quality estimation based on the associated phase information; b) determining signal quality information of the plurality of phase modulated digital symbols based on a predetermined number of determining symbol quality estimations; and c) said generating bit reliability information based upon the signal quality information and the phase information.
Claim 15
Dependent Claim
33 words
The method for providing bit reliability information of claim 12 wherein the step of determining a symbol quality estimation includes determining the phase error by comparing the phase information to predetermined phase information.
Claim 16
Dependent Claim
39 words
The method for providing bit reliability information of claim 12 wherein said step of determining a symbol quality estimation includes comparing a phase error signal associated with each digital symbol to a predetermined threshold for the phase error signal.
Claim 17
Dependent Claim
27 words
The method for providing bit reliability information of claim 12 wherein said step of determining signal quality information includes averaging the predetermined number of symbol quality estimations.
Claim 18
Dependent Claim
34 words
The method for providing bit reliability information of claim 12 wherein the step of generating bit reliability information includes generating a plurality of signals based upon the signal quality information and the phase information.
Claim 19
Dependent Claim
27 words
The method for providing bit reliability information of claim 12 wherein the step of generating bit quality information includes generating an in-phase component and a quadrature component.
Claim 20
Dependent Claim
94 words
A circuit for generating bit reliability information for phase modulated digital symbols comprising: a phase detector adapted to receive said phase modulated digital symbols for generating a phase estimate for each said phase modulated digital symbol; an error determiner coupled to receive said phase estimate, said error determiner generating a phase error signal; a signal quality determiner coupled to receive said phase error signal, said signal quality determiner generating a signal quality indicator; and a bit reliability indicator coupled to receive said signal quality indicator and said phase estimate and generate bit reliability information.
Claim 21
Dependent Claim
94 words
A circuit for generating bit reliability information for phase modulated digital symbols comprising: a phase detector adapted to receive said phase modulated digital symbols for generating a phase estimate for each said phase modulated digital symbol; an error determiner coupled to receive said phase estimate, said error determiner generating a phase error signal; a signal quality determiner coupled to receive said phase error signal, said signal quality determiner generating a signal quality indicator; and a bit reliability indicator coupled to receive said signal quality indicator and said phase estimate and generate bit reliability information.
Claim 22
Dependent Claim
22 words
The circuit for generating bit reliability information of claim 18 wherein said phase estimate is generated from a limited intermediate frequency signal.
Claim 23
Dependent Claim
42 words
The circuit for generating bit information of claim 18 wherein the error determiner includes a symbol detector coupled to receive said phase estimate and an adder circuit coupled to said symbol detector for subtracting an expected phase value from the phase estimate.
Claim 24
Dependent Claim
41 words
The circuit for generating bit information of claim 18 wherein said signal quality determiner includes a symbol quality estimator coupled to receive said phase error signal and generate symbol quality estimates and an averaging circuit coupled to said symbol quality estimator.
Claim 25
Dependent Claim
37 words
The circuit for generating bit reliability information of claim 18 wherein said bit reliability indicator includes a combiner circuit coupled to receive the signal quality indicator and the phase estimate and generate a bit reliability information signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-02-05 | 1999-08-07 | 2000-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-02-05 | 2003-08-07 | 2004-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-02-05 | 2007-08-07 | 2008-02-06 | $7700.00 | Window Closed / Lapsed |