Digital fast CORDIC for envelope tracking generation
First Claim
1. A coordinate rotation digital computer (CORDIC) for computing a norm of a vector having a first component and a second component, comprising:
- a first maximum value circuit for outputting a maximum operand that is a larger one of either an absolute value of the first component or an absolute value of the second component;
a minimum value circuit for outputting a minimum operand that is a smaller one of either an absolute value of the first component or an absolute value of the second component;
N rotator stages, each corresponding to a unique one of N predetermined vectors, each having a first multiply circuit for multiplying the maximum operand by a cosine coefficient of a corresponding predetermined vector to output a first rotation component, a second multiply circuit for multiplying the minimum operand by a sine coefficient of the corresponding predetermined vector to output a second rotation component and an adder circuit for adding the first rotation component to the second rotation component to output one of N results; and
a second maximum value circuit for outputting a maximum one of the N results.
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Accused Products
Abstract
Disclosed is a coordinate rotation digital computer (CORDIC) having a maximum value circuit that selects a larger of the first component or the second component. A minimum value circuit selects a minimum operand that is a smaller one of the first component or the second component. Also included are N rotator stages, each corresponding to a unique one of N predetermined vectors, each of the N rotator stages having a first multiply circuit to multiply the maximum operand by a cosine coefficient of a predetermined vector to output a first rotation component, a second multiply circuit for multiplying the minimum operand by a sine coefficient of the predetermined vector to output a second rotation component, and an adder circuit for adding the first rotation component to the second rotation component to output one of N results, and a maximum value circuit for outputting a maximum one of the N results.
238 Citations
20 Claims
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1. A coordinate rotation digital computer (CORDIC) for computing a norm of a vector having a first component and a second component, comprising:
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a first maximum value circuit for outputting a maximum operand that is a larger one of either an absolute value of the first component or an absolute value of the second component; a minimum value circuit for outputting a minimum operand that is a smaller one of either an absolute value of the first component or an absolute value of the second component; N rotator stages, each corresponding to a unique one of N predetermined vectors, each having a first multiply circuit for multiplying the maximum operand by a cosine coefficient of a corresponding predetermined vector to output a first rotation component, a second multiply circuit for multiplying the minimum operand by a sine coefficient of the corresponding predetermined vector to output a second rotation component and an adder circuit for adding the first rotation component to the second rotation component to output one of N results; and a second maximum value circuit for outputting a maximum one of the N results. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An envelope tracking system comprising:
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a power amplifier module (PAM); a fast switch mode power supply (SMPS) converter adapted to supply modulated power to the PAM in response to an envelope tracking signal (ETS); an envelope tracking signal (ETS) generator adapted to drive the SMPS converter in response to a stream of vector norms; and a CORDIC for computing a stream of vector norms, each having a first component and a second component, comprising; a first maximum value circuit for outputting a maximum operand that is a larger one of either an absolute value of the first component or an absolute value of the second component; a minimum value circuit for outputting a minimum operand that is a smaller one of either an absolute value of the first component or an absolute value of the second component; N rotator stages, each corresponding to a unique one of N predetermined vectors, each having a first multiply circuit for multiplying the maximum operand by a cosine coefficient of a corresponding predetermined vector to output a first rotation component, a second multiply circuit for multiplying the minimum operand by a sine coefficient of the corresponding predetermined vector to output a second rotation component and an adder circuit for adding the first rotation component to the second rotation component to output one of N results; and a second maximum value circuit for outputting a maximum one of the N results. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification