Self-interference mitigation in in-band full-duplex communication systems
A system and method for mitigating self-interference in mmWave systems. A transceiver can include a mutual precoder controller that controls both an analog/RF beamforming circuit and a digital/BB beamforming circuit to prefer beams directed along paths in the local RF environment that minimize self-interference. In other cases, a transceiver can include one or more self-interference filters to internally mitigate self-interference.
1 . A wireless transceiver pair for an in-band full duplex radio frequency (“RF”) communication system, the wireless transceiver pair comprising:
a first wireless transceiver comprising a first transmit side and a first receive side, the first transmit side comprising:
a first precoder receiving a first data stream as input, the first data stream corresponding to digital communications between the first wireless transceiver and a first endpoint device;
a second precoder receiving output of an RF chain as input; and
a first antenna array receiving output of the second precoder as input and configured to emit RF energy in a selected band into a local RF environment;
a second wireless transceiver comprising a second transmit side and a second receive side, the second receive side comprising:
a second antenna array receiving RF energy in the selected band from the local RF environment; and
a digital output configured to provide a second data stream as output based at least in part from the received RF energy, the second data stream corresponding to digital communications between the second wireless transceiver and a second endpoint device; and
a controller configured to execute an instance of a trained predictive model, the controller configured to:
estimate echo channel information in respect of the local RF environment based on the received RF energy received by the second wireless transceiver;
estimate channel interference information based at least in part on the echo channel information;
generate configuration parameters with, at least in part, the trained predictive model and the estimated channel interference information;
provide the configuration parameters to the first precoder and the second precoder based at least in part on the estimated channel interference information; and
apply the configuration parameters to both the first precoder and the second precoder based on channel interference information, the configuration parameters defining a composite analog/digital beamforming vector that produces, via a spatial radiation pattern of the first antenna array, at least one main lobe directed toward the first endpoint device and at least one null spatially aligned to the second antenna array so as to suppress RF energy that would otherwise return to and impinge on the second antenna array either directly or via at least one reflection path in the local RF environment.
2 . The wireless transceiver pair of claim 1 , wherein the controller is further configured to:
select digital beamforming parameters;
select a vector from an analog beamforming codebook; and
wherein the digital beamforming parameters and the selected vector cooperatively minimize the RF energy emitted by the first antenna array that returns to the second antenna array.
3 . The wireless transceiver pair of claim 1 wherein the first precoder is configured to output signals to the first antenna array that steer the at least one lobe and the at least one null in a direction that minimizes the RF energy emitted by the first antenna array that returns to the second antenna array.
4 . The wireless transceiver pair of claim 1 , wherein the first transmit side comprises:
a digital to analog converter receiving output of the first precoder as input; and
the RF chain receiving output of the digital to analog converter as input.
5 . The wireless transceiver pair of claim 4 , wherein the RF chain is a first RF chain and the second receive side comprises:
a first combiner receiving the received RF energy as input;
a second RF chain receiving output of the first combiner as input;
an analog to digital converter receiving output of the second RF chain as input; and
a second combiner receiving output of the analog to digital converter as input;
wherein:
the digital output receives output of the second combiner as input.
6 . The wireless transceiver pair of claim 1 wherein the controller is further configured to:
obtain known channel information; and
provide the configuration parameters based at least in part on the obtained known channel information.
7 . The wireless transceiver pair of claim 1 wherein the controller is configured to determine the configuration parameters for the first precoder and for the second precoder based at least in part on a set of predefined interference channels comprising a set of channels between the first transmit side and the second receive side.
8 . A system of radio frequency (“RF”) devices, the system comprising:
a first transceiver communicably coupled to a first endpoint device and comprising:
a first transmit side comprising a first transmit side antenna array; and
a first receive side comprising a first receive side antenna array; and
a second transceiver co-located with and communicably coupled to the first transceiver and communicably coupled to a second endpoint device and comprising:
a second transmit side comprising:
a baseband precoder and an RF precoder; and
a second transmit side antenna array;
a second receive side comprising a second receive side antenna array; and
a controller configured to instantiate an instance of a trained predictive model providing, as output, configuration parameters to both the baseband precoder of the second transceiver and the RF precoder of the second transceiver based on channel state information determined at least in part by the first transceiver, the configuration parameters defining a composite analog/digital beamforming vector that produces, via a spatial radiation pattern of the first transceiver, at least one main lobe directed toward the first endpoint device and at least one null spatially aligned to the second transceiver so as to suppress RF energy that would otherwise return to and impinge on the second transceiver either directly or via at least one reflection path in the local RF environment.
9 . The system of claim 8 , wherein the first receive side antenna array is co-located with the second receive side antenna array.
10 . The system of claim 9 , wherein the first transmit side antenna array is co-located with the second transmit side antenna array.
11 . The system of claim 8 , wherein the first transceiver is one of a radar transceiver, an RF jamming system, or an electronic warfare system.
12 . The system of claim 8 , wherein the first transceiver and the second transceiver are configured to operate in at least one overlapping band.
13 . The system of claim 8 , comprising a self-interference cancelation filter coupling output of the first transmit side to input of the second receive side.
14 . The system of claim 8 , comprising a self-interference cancelation filter coupling output of the baseband precoder to input of the first receive side.
15 . The system of claim 14 , wherein the self-interference cancelation filter introduces a phase shift to output of the first transmit side.
16 . The system of claim 8 , wherein the RF energy is emitted into a local RF environment by the first transmit side antenna array at least one frequency between 1 GHz and 300 GHz.
17 . The system of claim 8 , wherein:
the first receive side antenna array is co-located with the second receive side antenna array; and
the first transmit side antenna array is co-located with the second transmit side antenna array.
18 . A method of operating a wireless transceiver pair for an in-band full duplex radio frequency (“RF”) communication system, the method comprising:
receiving, in a selected band, RF energy;
estimating, from the received RF energy, information about a local RF environment;
estimating channel interference information based at least in part on the information about the local RF environment;
determining by providing the channel interference information as input to a trained predictive model, first beamforming parameters for a baseband precoder of the wireless transceiver pair based on the channel interference information, the first beamforming parameters configured to minimize interference resulting from transmission by a first transceiver of the wireless transceiver pair received at a receive antenna of a second transceiver of the wireless transceiver pair, the first transceiver communicably coupled to a first endpoint device and the second transceiver communicably coupled to a second endpoint device;
determining, by providing the channel interference information as input to the trained predictive model, second beamforming parameters for an RF precoder of the wireless transceiver based on the channel interference information, the second beamforming parameters configured to minimize interference resulting from transmission by the first transceiver received at the receive antenna of the second transceiver; and
applying the first and second configuration parameters to the baseband precoder and the RF precoder, respectively to cause via a spatial radiation pattern of the first transceiver, at least one main lobe directed toward the first endpoint device and at least one null spatially aligned to the second transceiver so as to suppress RF energy that would otherwise return to and impinge on the second transceiver either directly or via at least one reflection path in the local RF environment.
19 . The method of claim 18 , further comprising:
determining third beamforming parameters for an RF self-interference filter of the wireless transceiver based on the estimated channel interference, the third beamforming parameters configured to minimize self-interference received at an RF combiner of the wireless transceiver pair;
determining fourth beamforming parameters for a baseband self-interference filter of the wireless transceiver based on the estimated channel interference, the fourth configuration parameters configured to minimize self-interference received at a baseband combiner of the wireless transceiver; and
applying the third and fourth configuration parameters to the RF self-interference filter and the baseband self-interference filter, respectively.
20 . The method of claim 18 , wherein determining the first configuration parameters and the second configuration parameters is performed by leveraging an orthogonal matching pursuit algorithm.