Systems for integrated self-interference cancellation
A system for integrated self-interference cancellation, comprising a transmit coupler, coupled to a transmit signal, that samples the transmit signal to create a sampled transmit signal; an analog self-interference canceller, coupled to the transmit coupler, comprising a controller; a signal divider, that splits the sampled transmit signal into a set of signal components; a set of phase shifters, wherein a phase shifter of the set shifts a signal component of the set of signal components by a total phase shift value; a set of scalers, wherein a scaler of the set scales the signal component by a total scale factor; a signal combiner, that combines the set of signal components into a self-interference cancellation signal; and a receive coupler, coupled to a receive signal, that combines the self-interference cancellation signal with the receive signal to remove a portion of self-interference present in the receive signal.
1. A system for integrated self-interference cancellation, comprising:
a transmit coupler, communicatively coupled to a transmit signal of a full-duplex wireless transceiver, that samples the transmit signal to create a sampled transmit signal;
an analog self-interference canceller, coupled to the transmit coupler, the analog self-interference canceller comprising:
a controller;
a signal divider, that splits the sampled transmit signal into a set of signal components, the set of signal components transmitted by way of a set of transmit paths;
a set of phase shifters, coupled to the set of transmit paths, wherein a phase shifter of the set of phase shifters shifts a signal component of the set of signal components by a total phase shift value; wherein the phase shifter comprises a set of phase shift stages, each stage having a stage phase shift value, the set connected to the phase shifter by a set of switches; wherein the total phase shift value is set by a state configuration of the set of switches and the stage phase shift values of the set of phase shift stages;
a set of scalers, coupled to the set of transmit paths, wherein a scaler of the set of scalers scales the signal component by a total scale factor;
a signal combiner, coupled to the set of transmit paths, that combines the set of signal components into a self-interference cancellation signal; and
a receive coupler, communicatively coupled to a receive signal of the full duplex wireless transceiver, that combines the self-interference cancellation signal with the receive signal to remove at least a first portion of self-interference present in the receive signal.
2. The system of claim 1 , wherein the controller generates the state configuration.
3. The system of claim 2 , wherein the controller generates the state configuration by computing a desired phase shift output of the phase shifter and selecting the state configuration resulting in a closest total phase shift value to the desired phase shift output.
4. The system of claim 3 , wherein the state configuration is selected from a set of state configurations determined according to a hybrid thermometer code.
5. The system of claim 4 , wherein each stage phase shift value is predetermined such that the set of state configurations forms a piecewise linear approximation of a phase shift curve.
6. The system of claim 4 , wherein the set of phase shift stages comprises a subset of coarse phase shift stages and a subset of fine phase shift stages; wherein the subset of coarse phase shift stages corresponds to a binary component of the hybrid thermometer code; wherein the subset of fine phase shift stages corresponds to a thermometer component of the hybrid thermometer code.
7. The system of claim 2 , wherein the controller generates the state configuration by incrementing the state configuration according to a hybrid thermometer code.
8. The system of claim 7 , wherein each stage phase shift value is predetermined such that incrementing the state configuration the set of state configurations results in total phase shift values approximating a piecewise linear approximation of a phase shift curve.
9. The system of claim 2 , wherein each phase shift stage comprises an LC network.
10. A system for integrated self-interference cancellation, comprising:
a transmit coupler, communicatively coupled to a transmit signal of a full-duplex wireless transceiver, that samples the transmit signal to create a sampled transmit signal;
an analog self-interference canceller, coupled to the transmit coupler, the analog self-interference canceller comprising:
a controller;
a signal divider, that splits the sampled transmit signal into a set of signal components, the set of signal components transmitted by way of a set of transmit paths;
a set of phase shifters, coupled to the set of transmit paths, wherein a phase shifter of the set of phase shifters shifts a signal component of the set of signal components by a total phase shift value;
a set of scalers, coupled to the set of transmit paths, wherein a scaler of the set of scalers scales the signal component by a total scale factor; wherein the scaler comprises a set of scaler stages, each stage having a stage scale factor, the set connected to the scaler by a set of switches; wherein the total scale factor is set by a state configuration of the set of switches and the stage scale factors of the set of scaler stages;
a signal combiner, coupled to the set of transmit paths, that combines the set of signal components into a self-interference cancellation signal; and
a receive coupler, communicatively coupled to a receive signal of the full duplex wireless transceiver, that combines the self-interference cancellation signal with the receive signal to remove at least a first portion of self-interference present in the receive signal.
11. The system of claim 10 , wherein the controller generates the state configuration.
12. The system of claim 11 , wherein the controller generates the state configuration by computing a desired scaler output of the scaler and selecting the state configuration resulting in a closest total scale factor to the desired scaler output.
13. The system of claim 12 , wherein the state configuration is selected from a set of state configurations determined according to a hybrid thermometer code.
14. The system of claim 13 , wherein each stage scale factor is predetermined such that the set of state configurations forms a piecewise linear approximation of a scaling curve.
15. The system of claim 13 , wherein the set of scaler stages comprises a subset of coarse scaler stages and a subset of fine scaler stages; wherein the subset of coarse scaler stages corresponds to a binary component of the hybrid thermometer code; wherein the subset of fine scaler stages corresponds to a thermometer component of the hybrid thermometer code.
16. The system of claim 11 , wherein the controller generates the state configuration by incrementing the state configuration according to a hybrid thermometer code.
17. The system of claim 16 , wherein each stage scale factor is predetermined such that incrementing the state configuration the set of state configurations results in total scale factors approximating a piecewise linear approximation of a scaling curve.
18. The system of claim 11 , wherein each phase shift stage comprises a resistive attenuator.