Hybrid radio architecture for repeaters using RF cancellation reference
First Claim
1. 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:
- a first receiver circuit coupled to the first antenna to receive the input signal and to generate a digitized input signal, the first receiver circuit being an intermediate frequency subsampling receiver having an intermediate frequency higher than baseband;
a first transmitter circuit coupled to generate the amplified signal to transmit on the second antenna based on a digitized transmit signal, the first transmitter circuit being a direct conversion transmitter having an intermediate frequency at baseband;
a second receiver circuit coupled to receive at least a portion of a signal to be transmitted prior to transmission over the second antenna and to generate a digitized transmit reference signal, the second receiver circuit being an intermediate frequency subsampling receiver; and
a repeater baseband block configured to receive the digitized input signal from the first receiver circuit and to generate the digitized transmit signal for the first transmitter circuit, and further configured to receive the digitized transmit reference signal as a reference signal for channel estimation.
1 Assignment
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Accused Products
Abstract
A wireless repeater includes a receiver circuit implemented as an intermediate frequency (IF) subsampling receiver and a transmitter circuit implemented as a direct conversion (zero-IF) transmitter. The repeater further includes a reference receiver implemented as an IF subsampling receiver to sample a portion of the transmit signal prior to over-the-air transmission for use as the reference signal for channel estimation. Highly accurate channel estimation is obtained by using the reference signal from the reference receiver as the reference signal accounts for distortions in the transmitter circuit of the repeater. The repeater may include an echo canceller to cancel an estimated feedback amount from an input signal based on the channel estimation.
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Citations
22 Claims
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1. 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 coupled to the first antenna to receive the input signal and to generate a digitized input signal, the first receiver circuit being an intermediate frequency subsampling receiver having an intermediate frequency higher than baseband; a first transmitter circuit coupled to generate the amplified signal to transmit on the second antenna based on a digitized transmit signal, the first transmitter circuit being a direct conversion transmitter having an intermediate frequency at baseband; a second receiver circuit coupled to receive at least a portion of a signal to be transmitted prior to transmission over the second antenna and to generate a digitized transmit reference signal, the second receiver circuit being an intermediate frequency subsampling receiver; and a repeater baseband block configured to receive the digitized input signal from the first receiver circuit and to generate the digitized transmit signal for the first transmitter circuit, and further configured to receive the digitized transmit reference signal as a reference signal for channel estimation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. 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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first means for receiving the input signal from the first antenna and for generating a digitized input signal, the first means for receiving the input signal being an intermediate frequency subsampling receiver having an intermediate frequency higher than baseband; means for generating the amplified signal to transmit on the second antenna based on a digitized transmit signal, the means for generating the amplified signal being a direct conversion transmitter having an intermediate frequency at baseband; second means for receiving at least a portion of a signal to be transmitted prior to transmission over the second antenna and generating a digitized transmit reference signal, the second means for receiving being an intermediate frequency subsampling receiver; and means for receiving the digitized input signal from the first means for receiving and generating the digitized transmit signal for the means for generating the amplified signal, the means further for receiving the digitized transmit reference signal as a reference signal for channel estimation.
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17. A method for providing echo cancellation in a wireless repeater in a wireless communication system, 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; converting the input signal to an intermediate frequency signal at a first intermediate frequency; generating a digitized input signal by subsampling the intermediate frequency signal at a sampling frequency; generating in-phase and quadrature-phase digitized transmit signals based on the digitized input signal; converting the in-phase and quadrature-phase digitized transmit signals to quadrature analog transmit signals at baseband frequency; upconverting and combining the quadrature analog transmit signals to generate a signal at a transmission frequency; generating an amplified signal based on the signal at the transmission frequency; transmitting the amplified signal on the second antenna; receiving at least a portion of a signal to be transmitted prior to transmission over the second antenna and generating a digitized transmit reference signal by converting the portion of the signal to be transmitted to a second intermediate frequency signal at the first intermediate frequency and subsampling the second intermediate frequency signal at the sampling frequency; and estimating a feedback channel between the first antenna and the second antenna using the digitized transmit reference signal as a reference signal for channel estimation and providing a feedback channel estimate. - View Dependent Claims (18, 19, 20, 21, 22)
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Specification