Single channel full duplex wireless communications
First Claim
1. A method for self-interference cancellation comprising:
- sampling a digital transmit signal of a communication system;
converting the digital transmit signal into a radio frequency (RF) transmit signal;
wherein the RF transmit signal is an analog signal having a first center frequency;
wherein the first center frequency is a radio frequency;
sampling the RF transmit signal;
transmitting, at a set of transmit antennas of the communication system, the RF transmit signal;
receiving, at a set of receive antennas of the communication system, an RF receive signal of the communication system;
wherein the RF receive signal is an analog signal having a second center frequency;
wherein the second center frequency is identical to the first center frequency;
wherein the set of transmit antennas and the set of receive antennas are configured such that destructive interference removes a first portion of self-interference from the RF receive signal;
transforming, in the RF domain and without performing frequency downconversion, the sampled RF transmit signal into an RF self-interference cancellation signal;
wherein transforming the sampled RF transmit signal comprises attenuating, phase shifting, time delaying, and inverting the RF transmit signal;
combining, over a wired cancellation path, in order to remove a second portion of self-interference from the RF receive signal, the RF self- interference cancellation signal with the RF receive signal, resulting in a reduced-interference residual RF receive signal;
converting the reduced-interference residual RF receive signal into a reduced-interference residual digital receive signal;
transforming, in the digital domain, the sampled digital transmit signal into a digital self-interference cancellation signal using digital noise cancellation techniques; and
combining, in order to remove a third portion of self-interference from the reduced-interference residual digital receive signal, the digital self-interference cancellation signal with the reduced-interference residual digital receive signal, resulting in a further-reduced-interference residual digital receive signal.
1 Assignment
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Accused Products
Abstract
In one aspect there is provided a method. The method may include receiving a first analog radio frequency signal including a signal of interest and an interference signal caused by a second analog radio frequency signal transmitted in full duplex over a channel from which the first analog transmission is received; combining the first analog radio frequency signal and a portion of the second analog radio frequency signal to generate an output analog radio frequency signal characterized by at least a reduction or an elimination of the interference signal included in the output analog radio frequency signal; and providing the output analog radio frequency signal. Related apparatus, systems, methods, and articles are also described.
144 Citations
18 Claims
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1. A method for self-interference cancellation comprising:
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sampling a digital transmit signal of a communication system; converting the digital transmit signal into a radio frequency (RF) transmit signal;
wherein the RF transmit signal is an analog signal having a first center frequency;
wherein the first center frequency is a radio frequency;sampling the RF transmit signal; transmitting, at a set of transmit antennas of the communication system, the RF transmit signal; receiving, at a set of receive antennas of the communication system, an RF receive signal of the communication system;
wherein the RF receive signal is an analog signal having a second center frequency;
wherein the second center frequency is identical to the first center frequency;wherein the set of transmit antennas and the set of receive antennas are configured such that destructive interference removes a first portion of self-interference from the RF receive signal; transforming, in the RF domain and without performing frequency downconversion, the sampled RF transmit signal into an RF self-interference cancellation signal;
wherein transforming the sampled RF transmit signal comprises attenuating, phase shifting, time delaying, and inverting the RF transmit signal;combining, over a wired cancellation path, in order to remove a second portion of self-interference from the RF receive signal, the RF self- interference cancellation signal with the RF receive signal, resulting in a reduced-interference residual RF receive signal; converting the reduced-interference residual RF receive signal into a reduced-interference residual digital receive signal; transforming, in the digital domain, the sampled digital transmit signal into a digital self-interference cancellation signal using digital noise cancellation techniques; and combining, in order to remove a third portion of self-interference from the reduced-interference residual digital receive signal, the digital self-interference cancellation signal with the reduced-interference residual digital receive signal, resulting in a further-reduced-interference residual digital receive signal. - View Dependent Claims (2, 3, 4, 5)
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6. A method for self-interference cancellation comprising:
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sampling a radio frequency (RF) transmit signal;
wherein the RF transmit signal is an analog signal having a first center frequency;
wherein the first center frequency is a radio frequency;transmitting, at a transmit antenna of a communication system, the RF transmit signal; receiving, at a receive antenna of the communication system, an RF receive signal of the communication system;
wherein the RF receive signal is an analog signal having a second center frequency;transforming, in the RF domain and without performing frequency downconversion, the sampled RF transmit signal into an RF self-interference cancellation signal;
wherein transforming the RF transmit signal comprises attenuating, phase shifting, time delaying, and inverting the RF transmit signal; andcombining, over a wired cancellation path, in order to remove a first portion of self-interference from the RF receive signal, the RF self-interference cancellation signal with the RF receive signal, resulting in a reduced-interference residual RF receive signal; after sampling the RF transmit signal, converting the sampled RF transmit signal into an RF-sourced digital transmit signal; transforming, in the digital domain, the RF-sourced digital transmit signal into a digital self-interference cancellation signal using digital noise cancellation techniques; converting the reduced-interference residual RF receive signal into a reduced-interference residual digital receive signal; and combining, in order to remove a second portion of self-interference from the reduced-interference residual digital receive signal, the digital self-interference cancellation signal with the reduced-interference residual digital receive signal, resulting in a further-reduced-interference residual digital receive signal. - View Dependent Claims (7, 8, 9)
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10. A system for self-interference cancellation comprising:
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a transmitter, coupled to a set of transmit antennas, that transmits a radio frequency (RF) transmit signal having a first center frequency;
wherein the first center frequency is a radio frequency;
wherein the transmitter creates the RF transmit signal from a digital transmit signal;a signal splitter, communicatively coupled to the RF transmit signal, that samples the RF transmit signal to create a sampled RF transmit signal; a receiver, coupled to a set of receive antennas, that receives an RF receive signal having a second center frequency;
wherein the second center frequency is a radio frequency;an RF self-interference canceller, coupled to the signal splitter, that transforms, in the RF domain and without performing frequency downconversion, the sampled RF transmit signal into an RF self-interference cancellation signal;
wherein the RF self-interference canceller comprises an attenuator, an inverter, and at least one of a phase-shifter and a delay;a signal combiner, communicatively coupled to the RF self-interference cancellation signal and to the RF receive signal by wired signal paths, that combines the RF self-interference cancellation signal and the RF receive signal to produce a reduced-interference residual RF receive signal;
wherein the reduced-interference residual RF receive signal is characterized by reduction of a first portion of self-interference relative to the RF receive signal;
wherein the receiver converts the reduced-interference residual RF receive signal into a reduced-interference residual digital receive signal; anda digital self interference canceller that; samples the digital transmit signal; transforms, in the digital domain, the sampled digital transmit signal into a digital self-interference cancellation signal; and combines the digital self-interference cancellation signal and the reduced-interference residual digital receive signal to produce a further-reduced-interference residual digital receive signal;
wherein the further-reduced-interference residual digital receive signal is characterized by reduction of a second portion of self-interference relative to the RF receive signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification