Systems and methods for mitigation of self-interference in spectrally efficient full duplex communications
First Claim
1. A multi-stage self-interference cancellation system, the system comprising:
- a transmit signal sampling module coupled to a transmit signal path of a communication station and configured to sample a transmit signal after modification of the transmit signal by a nonlinear component of the transmit signal path, wherein the communication station is operable to transmit and receive using a same frequency simultaneously;
a receive signal sampling module coupled to a receive signal path of the communication station and configured to sample a radio frequency (RF) receive signal as received by the communication station including self-interference from the simultaneous transmitting and receiving using the same frequency;
a channel estimation module coupled to the transmit signal sampling module and the receive signal sampling module and configured to receive a transmit sample signal from the transmit signal sampling module and a receive sample signal from the receive signal sampling module, wherein the transmit sample signal and the receive sample signal undergo analog to digital conversion prior to reception by the channel estimation module, the channel estimation module further configure to determine a baseband channel estimate from the received transmit sample signal and the receive sample signal, and to perform digital to analog conversion of the baseband channel estimate to generate RF channel parameters;
an analog cancellation module coupled to the receive signal path and configured to provide an RF cancellation signal thereto, wherein combining the RF receive signal and the RF cancellation signal provides cancellation of strong self-interference resulting in a residual signal, and wherein the analog cancellation module comprises a multi-tap vector modulation module configured to generate the RF cancellation signal, wherein the RF channel parameters adaptively control the multi-tap vector modulation module to generate the RF cancellation signal to reduce interference in signals received over a time-varying multipath channel; and
a digital cancellation module coupled to the receive signal path and configured to provide a residual cancellation signal thereto, wherein combining the residual signal and the residual cancellation signal provides a desired receive signal having the self-interference mitigated.
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Accused Products
Abstract
Systems and methods which provide mitigation of self-interference in spectrally efficient full duplex (e.g., transmit and receive using the same frequency simultaneously) communications are described. Embodiments provide an interference mitigation structure having a multi-tap vector modulator interference cancellation circuit operable to cancel time varying multipath interference in the analog RF domain. A multi-tap vector modulator interference cancellation circuit of embodiments may comprise part of a multi-stage interference cancellation circuit, such as a multi-stage interference cancellation circuit comprising a multi-tap vector modulator interference cancellation circuit and a digital residual interference cancellation circuit. A digital residual interference cancellation circuit of embodiments provides residual interference cancellation. A multi-stage interference cancellation circuit configuration of embodiments is operable to provide cancellation of strong multipath signals as well as cancellation of residual multipath signals, including interference in the received signal associated with circulator leakage, antenna reflection and multipath.
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Citations
18 Claims
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1. A multi-stage self-interference cancellation system, the system comprising:
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a transmit signal sampling module coupled to a transmit signal path of a communication station and configured to sample a transmit signal after modification of the transmit signal by a nonlinear component of the transmit signal path, wherein the communication station is operable to transmit and receive using a same frequency simultaneously; a receive signal sampling module coupled to a receive signal path of the communication station and configured to sample a radio frequency (RF) receive signal as received by the communication station including self-interference from the simultaneous transmitting and receiving using the same frequency; a channel estimation module coupled to the transmit signal sampling module and the receive signal sampling module and configured to receive a transmit sample signal from the transmit signal sampling module and a receive sample signal from the receive signal sampling module, wherein the transmit sample signal and the receive sample signal undergo analog to digital conversion prior to reception by the channel estimation module, the channel estimation module further configure to determine a baseband channel estimate from the received transmit sample signal and the receive sample signal, and to perform digital to analog conversion of the baseband channel estimate to generate RF channel parameters; an analog cancellation module coupled to the receive signal path and configured to provide an RF cancellation signal thereto, wherein combining the RF receive signal and the RF cancellation signal provides cancellation of strong self-interference resulting in a residual signal, and wherein the analog cancellation module comprises a multi-tap vector modulation module configured to generate the RF cancellation signal, wherein the RF channel parameters adaptively control the multi-tap vector modulation module to generate the RF cancellation signal to reduce interference in signals received over a time-varying multipath channel; and a digital cancellation module coupled to the receive signal path and configured to provide a residual cancellation signal thereto, wherein combining the residual signal and the residual cancellation signal provides a desired receive signal having the self-interference mitigated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 18)
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13. A multi-stage self-interference cancellation method, the method comprising:
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sampling a transmit signal in a transmit signal path of a communication station after modification of the transmit signal by a nonlinear component of the communication station, wherein the communication station is operable to transmit and receive using a same frequency simultaneously; sampling a radio frequency (RF) receive signal in a receive signal path of the communication station, wherein the RF receive signal sampled includes self-interference from the simultaneous transmitting and receiving using the same frequency; performing analog to digital conversion of the sampled transmit signal and the sampled RF receive signal to produce a baseband transmit signal and a baseband receive signal; determining a baseband channel estimation using the baseband transmit signal and the baseband receive signal; generating RF channel parameters based upon the determined baseband channel estimation; generating an analog RF cancellation signal using multi-tap vector modulation, wherein the multi-tap vector modulation is adaptively controlled for time varying channel response using the RF channel parameters; combining the RF receive signal and the analog RF cancellation signal to provide cancellation of strong self-interference resulting in a residual signal; determining a residual channel estimate using the sampled transmit signal and a sample of the residual signal; generating a digital residual cancellation signal using the residual channel estimate; and combining the residual signal and the digital residual cancellation signal to provide a desired receive signal having the self-interference mitigated. - View Dependent Claims (14, 15, 16, 17)
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Specification