Apparatus and method for correcting signal imbalances using complex multiplication
First Claim
Patent Images
1. A complex multiplier for adjusting phase and/or gain imbalances in a digital signal comprising:
- a first set of multiplication units to multiply an in-phase (“
I”
) component of said signal by a first set of coefficients; and
a second set of multiplication units to multiply a quadrature (“
Q”
) component of said signal by a second set of coefficients,wherein said I and Q components are transmitted from an output of a fast-Fourier transform (“
FET”
) module, andwherein each of said coefficients in said first set and said second set are independently modifiable,and further comprising at least two adders, each adder arranged to sum an output of the first set of multiplication units together with an output of the second set of multiplication units produce an output result that is a linear function of both the I and Q components.
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Abstract
A complex multiplier is described for filtering a signal in the frequency domain. In one embodiment, additional, independent frequency coefficients are supplied by the complex multiplier so that gain and/or phase of the signal may be independently modified (i.e., gain may be modified without affecting phase and vice-versa).
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Citations
14 Claims
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1. A complex multiplier for adjusting phase and/or gain imbalances in a digital signal comprising:
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a first set of multiplication units to multiply an in-phase (“
I”
) component of said signal by a first set of coefficients; anda second set of multiplication units to multiply a quadrature (“
Q”
) component of said signal by a second set of coefficients,wherein said I and Q components are transmitted from an output of a fast-Fourier transform (“
FET”
) module, andwherein each of said coefficients in said first set and said second set are independently modifiable, and further comprising at least two adders, each adder arranged to sum an output of the first set of multiplication units together with an output of the second set of multiplication units produce an output result that is a linear function of both the I and Q components. - View Dependent Claims (2, 3)
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4. A complex multiplier for adjusting phase and/or gain imbalances in a signal comprising:
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a first set of multiplication units to multiply an in-phase (“
In”
) component of said signal by a first set of coefficients; anda second set of multiplication units to multiply a quadrature (“
Q”
) component of said signal by a second set of coefficients,wherein each of said coefficients in said first set and said second set are independently modifiable and wherein said I and Q components are transmitted from an output of a fast-Fourier transform (“
FFT”
) module. - View Dependent Claims (5, 6)
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7. A method for adjusting amplitude and/or phase imbalances in a digital complex signal comprising:
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providing one or more independently-adjustable coefficients; and
modifying the components I and Q of the complex signal by multiplying each of them with said independently-adjustable coefficients associated with said signal,wherein said coefficients are frequency coefficients and said multiplication is performed after a fast-Fourier transform (“
FET”
) is performed on said signal. - View Dependent Claims (8, 9)
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10. A complex multiplier comprising:
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means for multiplying an in-phase (“
I”
) component of said signal by a first set of coefficients;means for multiplying a quadrature (“
Q”
) component of said signal by a second set of coefficients; andwherein each of said coefficients in said first set and said second set are independently modifiable and further comprising at least two adder means, each adder means for summing an output of the first multiplier means together with an output of the second multiplier means to produce a signal output that is a linear function of both the I and Q components, and wherein said I and Q components are transmitted from an output of a fast-Fourier transform (“
FFT”
) module. - View Dependent Claims (11, 12, 13)
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14. A method for adjusting amplitude and/or phase imbalances in a digital complex signal comprising:
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providing one or more independently-adjustable coefficients; and
modifying the components I and Q of the complex signal by multiplying each of them with said independently-adjustable coefficients associated with said signal;adding products of each of said multiplications to produce a sum of said products; and performing an inverse FFT on said sum of said sum products.
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Specification