Full duplex reconfigurable antenna self-interference cancellation systems
Embodiments of full-duplex systems with reconfigurable antennas are described. In one embodiment, a full-duplex reconfigurable antenna transceiver includes a transmit chain, a receive chain, and a reconfigurable antenna having a plurality of reconfigurable modes. The transceiver may also include an antenna controller configured to set a mode of the reconfigurable antenna. According to other aspects, the transceiver may also include a signal processor configured to transmit a set of training symbols during a training interval. The antenna controller may be further configured to select a respective mode of the reconfigurable antenna for each training symbol in the set of training symbols. Additionally, the antenna controller may be configured to calculate a received Signal-of-Interest to Interferer Ratio (SIR) for each training symbol of the set of training symbols. In this context, a full-duplex system utilizing a reconfigurable antenna may achieve significant rate improvement compared to half-duplex systems.
1. A full-duplex transceiver, comprising:
a digital signal processor configured to modulate transmit data into transmit symbols and to demodulate receive symbols into receive data;
a transmit chain configured to transmit the transmit symbols over a first antenna;
a receive chain configured to receive the receive symbols over a second antenna, wherein at least one of the first antenna and the second antenna comprises an electrically reconfigurable antenna having a plurality of electrically-actuated reconfigurable antenna modes; and
an antenna controller configured to set a mode of the electrically reconfigurable antenna, wherein
the digital signal processor and the transmit chain are further configured to transmit a set of training symbols during a training interval; and
the antenna controller is further configured to select a respective mode of the electrically reconfigurable antenna for individual training symbols in the set of training symbols during the training interval.
2. The full-duplex transceiver of claim 1 , wherein the antenna controller is configured to select the mode of the electrically reconfigurable antenna based on a threshold performance metric of the transceiver during a data transmission interval.
3. The full-duplex transceiver of claim 1 , wherein a number of the set of training symbols is equal to a number of the plurality of electrically-actuated reconfigurable antenna modes of the electrically reconfigurable antenna.
4. The full-duplex transceiver of claim 1 , wherein a number of the set of training symbols is less than a number of the plurality of electrically-actuated reconfigurable antenna modes of the electrically reconfigurable antenna and is selected to achieve at least a threshold level of passive suppression.
5. The full-duplex transceiver of claim 1 , wherein the antenna controller is further configured to calculate a performance metric associated with one of the plurality of electrically-actuated reconfigurable antenna modes of the electrically reconfigurable antenna for each training symbol in the set of training symbols.
6. The full-duplex transceiver of claim 5 , wherein, after the training interval, the antenna controller is further configured to select a mode of the electrically reconfigurable antenna that maximizes or minimizes the performance metric.
7. The full-duplex transceiver of claim 1 , wherein:
the electrically reconfigurable antenna comprises a plurality of electrically-actuated electrical couplings between a plurality of parasitic elements;
the transmit chain is electrically coupled to the electrically reconfigurable antenna; and
the antenna controller is electrically coupled to control the electrically-actuated electrical couplings of the electrically reconfigurable antenna to select the mode of the electrically reconfigurable antenna from among the plurality of electrically-actuated reconfigurable antenna modes.
8. The full-duplex transceiver of claim 1 , wherein the transmit chain is configured to transmit the transmit symbols and the receive chain is configured to receive the receive symbols over a same carrier frequency simultaneously.
9. A method of reconfiguring a full-duplex transceiver, comprising:
transmitting, with a transmit chain of the transceiver, a set of training symbols during a training interval;
selecting, with an antenna controller, a respective mode of an electrically reconfigurable antenna of the transceiver for individual training symbols in the set of training symbols, the electrically reconfigurable antenna having a plurality of electrically-actuated reconfigurable antenna modes;
calculating, with the antenna controller, a performance metric associated with one of the plurality of electrically-actuated reconfigurable antenna modes of the electrically reconfigurable antenna for each of the set of training symbols; and
based on the performance metric associated with each of the set of training symbols, selecting, with the antenna controller, a mode of the electrically reconfigurable antenna for use during a data transmission interval.
10. The method of claim 9 , further comprising selecting the mode of the electrically reconfigurable antenna for use during the data transmission interval based further upon a threshold received Signal-of-Interest to Interferer Ratio (SIR) of the transceiver.
11. The method of claim 9 , wherein a number of the set of training symbols is equal to a number of the plurality of electrically-actuated reconfigurable antenna modes of the electrically reconfigurable antenna.
12. The method of claim 9 , wherein a number of the set of training symbols is less than a number of the plurality of electrically-actuated reconfigurable antenna modes of the electrically reconfigurable antenna and is selected to achieve at least a threshold level of passive suppression.
13. The method of claim 9 , wherein:
the electrically reconfigurable antenna comprises a plurality of electrically-actuated electrical couplings between a plurality of parasitic elements; and
the selecting comprises selecting each respective mode of the electrically reconfigurable antenna from among the plurality of electrically-actuated reconfigurable antenna modes.
14. A full-duplex transceiver, comprising:
a digital signal processor configured to transmit a set of training symbols during a training interval;
a transmit chain configured to transmit the set of training symbols over a first antenna;
a receive chain configured to receive a portion of the training symbols as self-interference over a second antenna, wherein at least one of the first antenna and the second antenna comprises an electrically reconfigurable antenna having a plurality of electrically-actuated reconfigurable antenna modes; and
an antenna controller configured to:
select a respective mode of the electrically reconfigurable antenna for individual training symbols in the set of training symbols during the training interval to calculate a performance metric; and
set a mode of the electrically reconfigurable antenna to reduce the self-interference based on the performance metric during a data transmission interval.
15. The full-duplex transceiver of claim 14 , wherein a number of the set of training symbols is less than a number of the plurality of electrically-actuated reconfigurable antenna modes of the antenna reconfigurable antenna and is selected to achieve at least a threshold level of passive suppression.
16. The full-duplex transceiver of claim 14 , wherein the antenna controller is further configured to calculate a performance metric associated with one of the plurality of electrically-actuated reconfigurable antenna modes of the electrically reconfigurable antenna for each training symbol in the set of training symbols.
17. The full-duplex transceiver of claim 16 , wherein, after the training interval, the antenna controller is further configured to select a mode of the electrically reconfigurable antenna that maximizes or minimizes the performance metric.
18. The full-duplex transceiver of claim 14 , wherein:
the electrically reconfigurable antenna comprises a patch array of parasitic elements and electrically-actuated electrical couplings between the patch array of parasitic elements; and
the antenna controller is electrically coupled to control the electrically-actuated electrical couplings of the electrically reconfigurable antenna to select the mode of the electrically reconfigurable antenna from among the plurality of electrically-actuated reconfigurable antenna modes.