IQ IMBALANCE COMPENSATION IN INTERFERENCE CANCELLATION REPEATER USING A ZERO-IF RADIO ARCHITECTURE
First Claim
Patent Images
1. A method in an interference cancellation repeater implemented using a zero-IF receiver and a zero-IF transmitter, the method comprising:
- receiving an input signal at a first antenna of the repeater, the input signal being a sum of a remote signal to be repeated and a feedback signal resulting from a feedback channel between the first antenna and a second antenna;
cancelling a feedback signal estimate from the input signal to generate an echo-cancelled signal;
delaying the echo-cancelled signal to generate a reference signal;
generating a numerator value from the echo-cancelled signal;
generating a denominator value from the input signal or the reference signal or both;
generating a metric being a ratio of the numerator value to the denominator value, the metric being indicative of an IQ imbalance in the repeater'"'"'s receiver and/or transmitter; and
compensating for the IQ imbalance in the repeater'"'"'s receiver and/or transmitter by applying an adaptive algorithm using the metric.
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Abstract
An interference cancellation repeater employing zero-IF or direct conversion radio architecture implements IQ imbalance compensation using a metric and an adaptive algorithm. The metric is based on the image rejection ratio of the repeater and is indicative of the level of spectral image caused by the repeater'"'"'s receiver or transmitter IQ imbalance.
53 Citations
22 Claims
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1. A method in an interference cancellation repeater implemented using a zero-IF receiver and a zero-IF transmitter, the method comprising:
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receiving an input signal at a first antenna of the repeater, the input signal being a sum of a remote signal to be repeated and a feedback signal resulting from a feedback channel between the first antenna and a second antenna; cancelling a feedback signal estimate from the input signal to generate an echo-cancelled signal; delaying the echo-cancelled signal to generate a reference signal; generating a numerator value from the echo-cancelled signal; generating a denominator value from the input signal or the reference signal or both; generating a metric being a ratio of the numerator value to the denominator value, the metric being indicative of an IQ imbalance in the repeater'"'"'s receiver and/or transmitter; and compensating for the IQ imbalance in the repeater'"'"'s receiver and/or transmitter by applying an adaptive algorithm using the metric. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method in an interference cancellation repeater implemented using a zero-IF receiver and a zero-IF transmitter, the method comprising:
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receiving an input signal at a first antenna of the repeater, the input signal being a sum of a remote signal to be repeated and a feedback signal resulting from a feedback channel between the first antenna and a second antenna; generating a numerator value being a conjugate auto-correlation function of the input signal; generating a denominator value being an auto-correlation function of the input signal; generating a metric being a ratio of the numerator value to the denominator value, the metric being indicative of an IQ imbalance in the repeater'"'"'s receiver and/or transmitter; and compensating for the IQ imbalance in the repeater'"'"'s receiver and/or transmitter by applying an adaptive algorithm using the metric.
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12. A wireless repeater having a first antenna and a second antenna to receive an input signal and transmit an amplified signal, the input signal being a sum of a remote signal to be repeated and a feedback signal resulting from a feedback channel between the first antenna and the second antenna, the repeater comprising:
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a first receiver circuit being a zero-IF receiver coupled to the first antenna to receive the input signal and to generate digitized input signals at baseband frequency; a first transmitter circuit being a zero-IF transmitter coupled to generate the amplified signal to transmit on the second antenna based on digitized transmit signals at baseband frequency; and a repeater baseband block configured to receive the digitized input signals from the first receiver circuit and to generate the digitized transmit signals for the first transmitter circuit, the repeater baseband block operative to access a feedback signal estimate, to cancel the feedback signal estimate from the digitized input signals to generate an echo-cancelled signal, and to delay the echo-cancelled signal to generate a reference signal, the repeater baseband block further operative to generate a metric being a ratio of a numerator value derived from the echo-cancelled signal and a denominator value derived from the input signal or the reference signal or both, the metric being indicative of an IQ imbalance in the repeater'"'"'s receiver and/or transmitter, wherein the repeater baseband block is operative to apply an adaptive algorithm using the metric to compensate for the IQ imbalance in the first receiver circuit and/or the first transmitter circuit. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A wireless repeater having a first antenna and a second antenna to receive an input signal and transmit an amplified signal, the input signal being a sum of a remote signal to be repeated and a feedback signal resulting from a feedback channel between the first antenna and the second antenna, the repeater comprising:
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a first receiver circuit being a zero-IF receiver coupled to the first antenna to receive the input signal and to generate digitized input signals at baseband frequency; a first transmitter circuit being a zero-IF transmitter coupled to generate the amplified signal to transmit on the second antenna based on digitized transmit signals at baseband frequency; and a repeater baseband block configured to receive the digitized input signals from the first receiver circuit and to generate the digitized transmit signals for the first transmitter circuit, the repeater baseband block operative to generate a metric being a ratio of a numerator value being a conjugate auto-correlation function of the input signal and a denominator value being an auto-correlation function of the input signal, the metric being indicative of an IQ imbalance in the repeater'"'"'s receiver and/or transmitter, wherein the repeater baseband block is operative to apply an adaptive algorithm using the metric to compensate for the IQ imbalance in the first receiver circuit and/or the first transmitter circuit.
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21. A wireless repeater having a first antenna and a second antenna to receive an input signal and transmit an amplified signal, the input signal being a sum of a remote signal to be repeated and a feedback signal resulting from a feedback channel between the first antenna and the second antenna, the repeater comprising:
first means for receiving the input signal from the first antenna and for generating digitized input signals at baseband frequency using direct conversion; means for generating the amplified signal to transmit on the second antenna based on digitized transmit signals at baseband frequency using direct conversion; means for receiving the digitized input signals from the first means and generating the digitized transmit signals, the means including a means for accessing a feedback signal estimate, canceling the feedback signal estimate from the digitized input signals to generate an echo-cancelled signal, and delaying the echo-cancelled signal to generate a reference signal, the means further for generating a metric being a ratio of a numerator value derived from the echo-cancelled signal and a denominator value derived from the input signal or the reference signal or both, the metric being indicative of an IQ imbalance in the repeater'"'"'s receiver and/or transmitter, the means further for applying an adaptive algorithm using the metric to compensate for the IQ imbalance in the first receiver circuit and/or the first transmitter circuit.
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22. A computer readable medium having stored thereon computer executable instructions for performing at least the following acts:
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receiving an input signal at a first antenna of the repeater, the input signal being a sum of a remote signal to be repeated and a feedback signal resulting from a feedback channel between the first antenna and a second antenna; cancelling a feedback signal estimate from the input signal to generate an echo-cancelled signal; delaying the echo-cancelled signal to generate a reference signal; generating a numerator value from the echo-cancelled signal; generating a denominator value from the input signal or the reference signal or both; generating a metric being a ratio of the numerator value to the denominator value, the metric being indicative of an IQ imbalance in the repeater'"'"'s receiver and/or transmitter; and compensating for the IQ imbalance in the repeater'"'"'s receiver and/or transmitter by applying an adaptive algorithm using the metric.
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Specification