US5414735A
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Method and apparatus for normalizing components of a complex signal
Assignee: Visteon Global Technologies Inc
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Filing: 1993-04-26
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Granted: 1995-05-09
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Expires: 2013-04-26
Abstract
Abstract A method and apparatus for normalizing the I and Q components of a complex signal is provided which includes an iterative determination of the multiplier constant required for normalization. The I and Q components are squared and added together to create a digital word A constrained between certain limits. An iterative approach is implemented to arrive at a multiplier constant K which is equal to ##EQU1## without resorting to the use of multipliers. The constant K is then used to normalize the I and Q components.
Inventors
- 👤 William J. Whikehart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:17
CPC Classifications
H; H03; H03D; H03D3/00; H03D3/007; H03D3/009; H03D3/006
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
162 words
A method of processing digital signals to normalize multi-bit digital words representing the I 1 and Q 1 components of a complex signal of the form I 1 +jQ 1 to produce corresponding components I 3 and Q 3 , such that the square root of the sum of the squares of I 3 and Q 3 is equal to 1, comprising the steps of: a. performing a coarse normalization of I 1 and Q 1 to produce components I 2 and Q 2 respectively, b. calculating a value A equal to the sum of the squares of I 2 and Q 2 so that A is constrained to be equal to or greater than a minimum value R and less than a maximum value S, c. iteratively adjusting the value of a digital word K, until K 2 A=R d. producing the components I 3 and Q 3 , where I 3 =G(KI 2 ) and Q 3 =G(KQ 2 ).
Claim 2
Independent Claim
162 words
A method of processing digital signals to normalize multi-bit digital words representing the I 1 and Q 1 components of a complex signal of the form I 1 +jQ 1 to produce corresponding components I 3 and Q 3 , such that the square root of the sum of the squares of I 3 and Q 3 is equal to 1, comprising the steps of: a. performing a coarse normalization of I 1 and Q 1 to produce components I 2 and Q 2 respectively, b. calculating a value A equal to the sum of the squares of I 2 and Q 2 so that A is constrained to be equal to or greater than a minimum value R and less than a maximum value S, c. iteratively adjusting the value of a digital word K, until K 2 A=R d. producing the components I 3 and Q 3 , where I 3 =G(KI 2 ) and Q 3 =G(KQ 2 ).
Claim 3
Dependent Claim
11 words
The method defined in claim 1 wherein R=0.0625, S=0.5, and G=4.
Claim 4
Dependent Claim
62 words
The method defined in claim 1 wherein A is coarse normalized to produce a value A2 by shifting A left by 1, 2, or 3 bit positions to accomplish a multiplication of 2, 4 or 8 respectively such that R=0.5 and S=1 and G=4, and multiplying each of I 2 and Q 2 by ##EQU7## Respectively prior to performing step (d) .
Claim 5
Dependent Claim
162 words
Apparatus for processing digital signals to normalize multi-bit digital words representing the I 1 and Q 1 components of a complex signal of the form I 1 +jQ 1 to produce corresponding components I 3 and Q 3 , such that the square root of the sum of the squares of I 1 and Q 1 is equal to 1, comprising: means for performing a coarse normalization of I 1 and Q 1 to produce components I 2 and Q 2 respectively, means for calculating a value A equal to the sum of the squares of I 2 and Q 2 so that A is constrained to be equal to or greater than a minimum value R and less than a maximum value S, means for iteratively adjusting the value of a digital word K, until K 2 A=R means for producing the components I 3 and Q 3 , where I 3 =G(KI 2 ) and Q 3 =G(KQ 2 ).
Claim 6
Dependent Claim
162 words
Apparatus for processing digital signals to normalize multi-bit digital words representing the I 1 and Q 1 components of a complex signal of the form I 1 +jQ 1 to produce corresponding components I 3 and Q 3 , such that the square root of the sum of the squares of I 1 and Q 1 is equal to 1, comprising: means for performing a coarse normalization of I 1 and Q 1 to produce components I 2 and Q 2 respectively, means for calculating a value A equal to the sum of the squares of I 2 and Q 2 so that A is constrained to be equal to or greater than a minimum value R and less than a maximum value S, means for iteratively adjusting the value of a digital word K, until K 2 A=R means for producing the components I 3 and Q 3 , where I 3 =G(KI 2 ) and Q 3 =G(KQ 2 ).
Claim 7
Dependent Claim
11 words
The apparatus defined in claim 4 wherein R=0.0625, S=0.5, and G=4.
Claim 8
Dependent Claim
81 words
The apparatus defined in claim 4 further comprising means for coarse normalizing A by shifting A left by 1, 2, or 3 bit positions to accomplish a multiplication of 2, 4 or 8 respectively such that R=0.5, S=1, and G=4 and means for multiplying each of I 2 and Q 2 by 0.5 when A is shifted 1 bit position, by ##EQU8## when A is shifted by 2 bit positions, and by 1.0 when A is shifted by 3 bit positions.
Claim 9
Independent Claim
180 words
A method of normalizing multi-bit digital words representing the I 1 and Q 1 components of a complex signal of the form I 1 +jQ 1 to produce corresponding components I 3 and Q 3 , where the square root of the sum of the squares of I 3 and Q 3 is equal to 1, comprising the steps of: (a) performing a coarse normalization of the components I 1 and Q 1 to obtain component I 2 and Q 2 where each of |I 2 | and |Q 2 | is less than 0.5 and at least one of |I 2 |and |Q 2 | is equal to or greater than 0.25, (b) squaring the components I 2 and Q 2 and adding the squared components to obtain a digital word of value A equal to or greater than 0.0625 and less than 0.5, (c) iteratively adjusting the value of a digital word K, until K 2 A=0.0625, (d) producing the components I 3 and Q 3 , where I=4 (KI 2 ) and Q 3 =4(KQ 2 ).
Claim 10
Independent Claim
180 words
A method of normalizing multi-bit digital words representing the I 1 and Q 1 components of a complex signal of the form I 1 +jQ 1 to produce corresponding components I 3 and Q 3 , where the square root of the sum of the squares of I 3 and Q 3 is equal to 1, comprising the steps of: (a) performing a coarse normalization of the components I 1 and Q 1 to obtain component I 2 and Q 2 where each of |I 2 | and |Q 2 | is less than 0.5 and at least one of |I 2 |and |Q 2 | is equal to or greater than 0.25, (b) squaring the components I 2 and Q 2 and adding the squared components to obtain a digital word of value A equal to or greater than 0.0625 and less than 0.5, (c) iteratively adjusting the value of a digital word K, until K 2 A=0.0625, (d) producing the components I 3 and Q 3 , where I=4 (KI 2 ) and Q 3 =4(KQ 2 ).
Claim 11
Dependent Claim
96 words
The method defined in claim 7 wherein the value A obtained in step (b) is multiplied by a value of 2, 4, or 8 such that A is equal to or greater than 0.5 and less than 1, and wherein the value of K obtained in step (c) is such that K 2 A =0.5, and further wherein the component I 3 =4(K (CI 2 )) and Q 3 =4 (K(CQ 2 )) where C=0.5 when A is multiplied by 2, ##EQU9## when A is multiplied by 4, and C=1 when A is multiplied by 8.
References Cited (Backward Citations)
US4592074A
Cited
US5230099A
Cited
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