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Patent US4692889A successfully refreshed from Google Patents.
US4692889A
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Circuitry for calculating magnitude of vector sum from its orthogonal components in digital television receiver
Assignee: RCA Licensing Corp
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Filing: 1984-09-28
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Granted: 1987-09-08
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Expires: 2004-09-28
Abstract
Abstract An arrangement is provided for computing the magnitude value of the vector sum of two quadrature-related component signals I and Q with a minimal of hardware. To this end, the magnitude values of the orthogonal I and Q signals are applied to a ROM as address codes to produce the LogB ¦I¦ and LogB ¦Q¦ values to the logarithmic base B. The smaller of the LogB ¦I¦ and LogB ¦Q¦ logarithmic values is subtracted from the larger of the logarithmic values to produce the absolute value ¦D¦ of the difference between the respective logarithmic values. The difference value D is applied to a ROM as an address code which is programmed to generate a correction value F=0.5 LogB (1+B-2¦D¦). The correction value F is added to the larger of the two logarithmic values, and the antilog of the sum is computed to determine the magnitude value C of the vector sum of the two quadrature signals I and Q.
Inventors
- 👤 David L. McNeely
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:17
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; G; G06; G06F; G06F7/00; G06F7/38; G06F7/48; G06F7/544; G06F7/552; G06F1/00; G06F1/02; G06F1/03; G06F1/035; G06F1/0356; G06F7/4806; G06F7/483; G06F7/487; G06F2101/00; G06F2101/08; G06F2207/00; G06F2207/552; G06F2207/5525
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
174 words
Apparatus for generating the magnitude value of the vector sum of a pair of quadrature-related component vectors comprising: means for receiving the magnitude values I and Q of said pair of quadrature-related component vectors; means for generating an associated pair of logarithmic values Log B |I| and Log B |Q| to a base B; means for calculating the absolute value |D| of the difference between said logarithmic values Log B |I| and Log B |Q|; means for generating a correction value F(|D|) equal to 0.5 Log B (1+B -2 |D|); means including means for determining the larger of said logarithmic values Log B |I| and Log B |Q|, and for adding the correction value to the larger of the logarithmic values Log B |I| and Log B |Q|; and means for producing the antilog of the sum of the correction value and the larger of the logarithmic values Log B |I| and Log B |Q|, to generate a value C substantially equal to the magnitude of the vector sum of said quadrature-related component vectors.
Claim 2
Dependent Claim
174 words
Apparatus for generating the magnitude value of the vector sum of a pair of quadrature-related component vectors comprising: means for receiving the magnitude values I and Q of said pair of quadrature-related component vectors; means for generating an associated pair of logarithmic values Log B |I| and Log B |Q| to a base B; means for calculating the absolute value |D| of the difference between said logarithmic values Log B |I| and Log B |Q|; means for generating a correction value F(|D|) equal to 0.5 Log B (1+B -2 |D|); means including means for determining the larger of said logarithmic values Log B |I| and Log B |Q|, and for adding the correction value to the larger of the logarithmic values Log B |I| and Log B |Q|; and means for producing the antilog of the sum of the correction value and the larger of the logarithmic values Log B |I| and Log B |Q|, to generate a value C substantially equal to the magnitude of the vector sum of said quadrature-related component vectors.
Claim 3
Dependent Claim
53 words
Apparatus as defined in claim 1 wherein said means for calculating the difference between said logarithmic values Log B |I| and Log B |Q| comprises: means for determining the the smaller of said logarithmic values, and further means for subtracting the smaller of said logarithmic values from the larger of said logarithmic values.
Claim 4
Dependent Claim
53 words
Apparatus as defined in claim 2 wherein said subtracting means consists of: means for determining a 2's complement of said smaller logarithmic value; and means for additively combining said 2's complement of said smaller logarithmic value with said larger logarithmic value to obtain the absolute value of said difference between said logarithmic values.
Claim 5
Dependent Claim
49 words
Apparatus as defined in claim 3 wherein said 2's complement determining means comprises: means for inverting the bits of said smaller logarithmic value; and means for adding a +1 to the least significant bit position of the inverted value of said smaller logarithmic value to generate said 2's complement.
Claim 6
Dependent Claim
50 words
Apparatus as defined in claim 1 wherein said logarithmic value generating means comprises a ROM to which the I and Q amplitude values are applied as address codes, and which is programmed to contain the associated logarithmic values Log B |I| and Log B |Q| at the respective memory locations.
Claim 7
Dependent Claim
46 words
Apparatus as defined in claim 1 wherein said correction value generating means consists of a ROM to which an absolute difference value |D| is applied as an address code, and which is programmed to contain the associated correction value F(|D|) value at the corresponding memory location.
Claim 8
Dependent Claim
46 words
Apparatus as defined in claim 1 wherein said antilog producing means comprises a ROM to which an output of said means including means for adding is applied as an address code, and which is programmed to contain the associated antilog value at the respective memory location.
Claim 9
Dependent Claim
157 words
Apparatus for generating the magnitude value of the vector sum of a pair of quadrature-related component vectors comprising: an input port for applying the amplitude values I and Q of said pair of quadrature-related component vectors; means, coupled to said input port, for generating an associated pair o logarithmic values Log B |I| and Log B |Q| to a base B; means, coupled to said generating means, for subtracting one of said logarithmic values from the other of said logarithmic values to form a difference value D; means, coupled to said subtracting means, for generating a correction value equal to 0.5 Log B (1+B -2D ); means, coupled to said correction value generating means, for adding said correction value to said other logarithmic value; and means for producing the antilog of the output value of said adding means to generate a value C substantially equal to the magnitude of the vector sum of said quadrature-related component vectors.
Claim 10
Dependent Claim
157 words
Apparatus for generating the magnitude value of the vector sum of a pair of quadrature-related component vectors comprising: an input port for applying the amplitude values I and Q of said pair of quadrature-related component vectors; means, coupled to said input port, for generating an associated pair o logarithmic values Log B |I| and Log B |Q| to a base B; means, coupled to said generating means, for subtracting one of said logarithmic values from the other of said logarithmic values to form a difference value D; means, coupled to said subtracting means, for generating a correction value equal to 0.5 Log B (1+B -2D ); means, coupled to said correction value generating means, for adding said correction value to said other logarithmic value; and means for producing the antilog of the output value of said adding means to generate a value C substantially equal to the magnitude of the vector sum of said quadrature-related component vectors.
Claim 11
Dependent Claim
47 words
Apparatus as defined in claim 8 wherein said subtracting means consists of: means for determining a 2's complement of said one logarithmic value; and means for additively combining said 2's complement of said one logarithmic value with said other logarithmic value to obtain said difference value D.
Claim 12
Dependent Claim
50 words
Apparatus as defined in claim 8 wherein said logarithmic value generating means comprises a ROM to which the I and Q amplitude values are applied as address codes, and which is programmed to contain the associated logarithmic values Log B |I| and Log B |Q| at the respective memory locations.
Claim 13
Dependent Claim
43 words
Apparatus as defined in claim 8 wherein said correction value generating means consists of a ROM to which a difference value D is applied as an address code, and which is programmed to contain the associated correction value at the corresponding memory location.
Claim 14
Dependent Claim
43 words
Apparatus as defined in claim 8 wherein said antilog producing means comprises a ROM to which the output of said adding means is applied as an address code, and which is programmed to contain the associated antilog value at the respective memory location.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-07 | 1991-03-09 | 1991-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-07 | 1995-03-09 | 1995-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-07 | 1999-03-09 | 1999-09-08 | $7700.00 | Window Closed / Lapsed |