Patent Publication Number: US-11664877-B1

Title: Terrestrial interference correction using hybrid beamforming technology

Description:
BACKGROUND 
     A large and growing population of users is enjoying entertainment through the consumption of digital media items, such as music, movies, images, electronic books, and so on. The users employ various electronic devices to consume such media items. Among these electronic devices (referred to herein as endpoint devices, user devices, clients, client devices, or user equipment) are electronic book readers, cellular telephones, Personal Digital Assistants (PDAs), portable media players, tablet computers, netbooks, laptops, and the like. These electronic devices wirelessly communicate with a communications infrastructure to enable the consumption of the digital media items. In order to communicate with other devices wirelessly, these electronic devices include one or more antennas. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present inventions will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the present invention, which, however, should not be taken to limit the present invention to the specific embodiments, but are for explanation and understanding only. 
         FIG.  1    is a block diagram of a communication system including a communication device with an interference correction module, according to embodiments of the present disclosure. 
         FIG.  2    is a functional diagram of a communication device with analog beamforming (ABF) circuitry and digital beamforming (DBF) circuitry, according to embodiments of the present disclosure. 
         FIG.  3    depicts a hybrid beamforming interference correction process corresponding to a communication device, according to embodiments of the present disclosure. 
         FIG.  4    depicts an interference map generation process, according to embodiments of the present disclosure. 
         FIGS.  5 A-B  illustrate interference maps indicating signal interference of a surrounding environment of a communication device, according to embodiments of the present disclosure. 
         FIGS.  6 A-D  depict graphs illustrating the signal-to-noise (SNR) degradation associated with terrestrial signal interference, according to embodiments of the present disclosure. 
         FIG.  7    is a flow diagram of a method for hybrid beamforming interference correction, according to embodiments of the present disclosure. 
         FIG.  8    illustrates a portion of a communication system that includes two satellites of a constellation of satellites, each satellite being in orbit, according to embodiments of the present disclosure. 
         FIG.  9    is a functional block diagram of some systems associated with the satellite, according to some implementations. 
         FIG.  10    illustrates a satellite including an antenna system that is steerable, according to embodiments of the present disclosure. 
         FIG.  11    illustrates a simplified schematic of an antenna, according to embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Technologies directed to canceling terrestrial interference using hybrid beamforming technology are described. Frequency bands 17.7-18.3 GHz, and 19.3-19.7 GHz are commonly shared by fixed service (e.g., Terrestrial) and fixed satellite communication. The Federal Communication Commission (FCC) has granted over 21,000 licenses for fixed service (FS) over the United States territory. The presence of many signals of various communicating entities using overlapping bandwidths across overlapping locations may result in signal interference. For example, communication channels may include a satellite user downlink (e.g., 17.8-18.2 GHz) and a gateway downlink (e.g., 19.3-20.2 GHz). These exemplary communication channels may experience channel interference from the many licensed fixed service communication devices. 
     Effects of fixed service interference with both user downlink bandwidths and gateway downlinks are experienced differently. Conventionally, gateway site planning typically selects a location free of terrestrial interference. Once the FCC grants a license to a satellite gateway, future operators seeking a license must avoid interfering with the satellite gateway. However, there is often limited professional site planning for customer terminals (CTs) in conventional methodologies. Later, fixed service operators do not need to protect existing CTs that often use a blanket license. The presence of fixed service operators can impose challenges to satellite downlink radio frequency (RF) receiving chains. Conventional satellite receiver designs include RF chains capable for handling noise-limited scenarios. Components of conventional RF chains often employ devices (e.g., low noise amplifiers (LNAs), analog-to-digital converters (ADCs), and automatic gain controllers (AGCs)) with relatively small dynamic ranges. Excessive terrestrial interference may demand a larger dynamic range, which, if resolved by employing different hardware components can result in significantly increased cost. 
     Conventionally, fixed service interference can have a relatively large impact (e.g., exceeding receiver&#39;s dynamic range by several dBs). The interference can result in ADC saturation (e.g., the signal is processed outside an operational range of RF chain device (e.g., ADC)). Cancelation of the terrestrial interference, at least in part, can improve the processing of a receive signal (e.g., by reducing the clipping of the ADC). Conventionally, interference cancellations such as spatial domain interference, Zero forcing, minimum mean square error (MMSE), and incremental related carriers (IRC) algorithm are used to minimize the impact of interference on signal-to-noise (SNR). However, all of these identified conventional techniques rely on an accurate channel estimation. For example, if the channel estimation is inaccurate, the cancellation effect may be sub-optimal. 
     Aspects of the present disclosure overcome the deficiencies of conventional interference corrections systems and methods. Often the fixed service interference arrival is typically around the horizon while the receive signal from the satellite arrives with a certain elevation angle above ground. Conventionally, a CT directs a receive beam (Rx) (in both analog and digital beamforming) towards a target device (e.g., artificial satellite). The present disclosure includes directing the analog beamforming device to steer away from the target satellite to avoid RF saturation (e.g., ADC clipping). The present disclosure further includes performing an interference survey (e.g., to find a beamforming angle to point the analog beam direction). The interference survey is performed by scanning various beamforming directions and determining whether RF saturation occurs at associated directions. The interference survey may be used in a live signal reception environment to determine whether further steering is needed (e.g., a direction on the interference survey) to overcome the inference (e.g., ADC clipping). For example, the interference survey may indicate all possible neighboring directions (e.g., elevation angles and azimuth angles) that overcome the interference (e.g., do not experience ADC clipping), and a direction that overcomes the interference may be selected. In some embodiments, the direction may be prioritized by further criteria. For example, directions that overcome the interference may be further compared to determine which directions result in the best SNR conditions. 
     In an exemplary embodiment, a communication device may include an array antenna and an analog beamforming (ABF) device coupled to a set of antenna elements of the array antenna. The ABF device may include a phase shifter coupled to a first antenna element and a signal amplifier coupled to the first antenna element. The communication system may further include a digital beamforming (DBF) device coupled to the analog beamforming device. The DBF device includes: an analog-to-digital converter (ADC). The communication system may further include a memory coupled to the DBF device and the ABF device. The communication system may further include a controller coupled to the memory, the DBF device, and the ABF device. The controller may configure the ABF device and the DBF device to receive a first RF signal along a first analog beam direction corresponding to a first position of a first communication device (e.g., an artificial satellite). The controller may further determine a saturation condition of the DBF device corresponding to the first RF signal. The saturation condition may be attributed to a portion of the first RF signal received from a second communication device (e.g., a fixed service terrestrial device). The controller generates first data indicating a set of analog beam directions proximate to the first analog beam direction and whether the saturation condition is met for each of the set of analog beam directions. The controller further determines a second analog beam direction associated with a second position of the first communication device. The controller further configures the ABF device and the DBF device to receive a second RF signal along the second analog beam direction. 
     In another exemplary embodiment, a method includes causing, by a controller, an RF chain of a first wireless device to direct a receive beam along a first direction corresponding to a first position of a second wireless device (e.g., satellite). The first position is disposed along the first direction. The method further includes receiving a first RF signal by the first wireless device with the receive beam directed along the first direction. The method further includes determining, by the controller, that a saturation condition is present in association with processing the first RF signal by the first wireless device. The method further includes retrieving, by the controller, first data indicating a set of directions of receive beams and corresponding statuses of the saturation condition. The method further includes determining a second direction by the controller using the first data. The first data indicates that the second direction corresponds to an absence of the saturation condition. The method further includes causing, by the controller, the RF chain to direct the receive beam along the second direction. The method further includes receiving a second RF signal by the first wireless device with the receive beam directed along the second direction. 
       FIG.  1    is a block diagram of a communication system  100  including a communication device with interference correction module  134 , according to embodiments of the present disclosure. Communication system  100  includes communication devices  110 ,  120 , and  130 . Communication device  110  may transmit signals (e.g., using fixed service satellite transmitter  112  or more generally an RF signal transmitter). Communication device  110  may include an artificial satellite and may include one or more satellite communication devices (e.g., discussed further in  FIGS.  8 - 12   ). The fixed service transmitter  112  may include signal transmission devices (e.g., digital beamforming (DBF) circuitry, analog beamforming (ABF) circuitry) to generate and transmit a signal  150  (e.g., satellite downlink, fixed service transmission) to communication device  130 . The signal  150  may correspond to a satellite downlink and/or uplink. 
     As shown in  FIG.  1   , communication system  100  includes a communication device  120  (e.g., interfering device). Communication device  120  may include fixed service transmitter  122  that sends signals  152  that interfere with signals  150  from communication device  130 . The fixed service transmitter  122  may include signal transmission devices (e.g., digital beamforming (DBF) circuitry, analog beamforming (ABF) circuitry to generate and transmit a signal  150  (e.g., fixed service transmission) to communication device  130 . The signal  150  may correspond to a satellite downlink and/or uplink. 
     In some embodiments, communication devices  110 ,  120 , and  130  utilize the Wi-Fi® or IEEE 802.11 standard protocol. In other embodiments, the wireless connections may use some other wireless protocol, such as the current 3rd Generation Partnership Project (3GPP) long term evolution (LTE), or time division duplex (TDD)-Advanced systems. 
     Communication devices  110 ,  120 , and  130  may each include one or more antennas, receivers, transmitters, or transceivers that are configured to utilize a wireless local area network (WLAN) protocol, such as the Wi-Fi® or IEEE 802.11 standard protocol, other radio protocols, such as 3GPP LTE, or TDD-Advanced, or any combination of these or other communications standards. In one embodiment, the wireless communications between communication devices  110 ,  120 , and  130  may utilize the same Wi-Fi® or IEEE 802.11 standard protocol or other protocols such as Bluetooth®, ZigBee, near field communications (NFC), or other protocols capable of communicating digitally encoded signal (e.g., cyclostationary digitally encoded RF signals). 
     Communication devices  110 ,  120 , and  130  may comprise one or more directional or omnidirectional antennas (e.g., antenna  148 , antenna  156 , antenna  142 ), including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of radio frequency (RF) signals. In some embodiments, instead of two or more antennas, a single antenna with multiple apertures may be used. In these embodiments, each aperture may be considered a separate antenna. In some embodiments, communication devices  110 ,  120 , and  130  may utilize multiple-input multiple-output (MIMO) circuits and/or methodology. For example, antennas may be effectively separated to utilize spatial diversity and the different channel characteristics that may result between each of the antennas and the antennas of a transmitting station. In some MIMO embodiments, antennas may be separated by up to 1/10 of a wavelength or more. 
     In some embodiments, communication device  110  generates digitally encoded RF signals using one or more digital modulation schemes. In embodiments, communication device  110  leverages orthogonal frequency-division multiplexing (OFDM) to generate signal  150 . OFDM is a digital multi-carrier modulation scheme that extends the concept of single subcarrier modulation by using multiple subcarriers within the same single channel. Rather than transmit a high-rate stream of data with a single subcarrier, OFDM makes use of a large number of closely-spaced orthogonal subcarriers that are transmitted in parallel. Each subcarrier is modulated with a conventional digital modulation scheme (such as quadrature phase shift keying (QPSK), 16QAM, etc.) at a symbol rate, T s . However, the combination of many subcarriers enables data rates similar to conventional single-carrier modulation schemes within equivalent bandwidths. 
     In some embodiments, communication device  110  leverages quadrature amplitude modulation (QAM) to generate signals  150 . QAM includes a signal in which two carriers are shifted in phase by 90 degrees (e.g., sine and cosine) are modulated and combined. As a result of the phase difference, the phase-shifted carriers are in quadrature one with the other. Each of the signals includes a symbol rate, T s , associated with a rate (e.g., frequency), the digital symbols occur within the QAM signal. 
     As shown in  FIG.  1   , communication device  130  receives signals  150  and signal  152  from communication device  110  and communication device  120 . Communication device  130  includes processing device  132 , memory device  138 , and RF chain  136 . The RF Chain  136  (e.g., antennas, ABF, low-noise amplifier (LNA), automatic gain controller (AGC), analog-to-digital converter (ADC), digital beamforming (DBF) device, etc. as will be discussed further in later embodiments) processes the received signals (e.g., directs analog and digital beamforming components, converts the signal to a digital representation, and processing the digital information) to produce digital samples of the received signal. As shown in  FIG.  1   , communication device  130  includes one or more processing devices  132 , such as one or more CPUs, microcontrollers, field programmable gate arrays, or other types of processors. Processing device  132  processing the digital samples. Processing device  132  implements the interference correction module  134 . 
     Communication device  130  includes one or more processor(s)  132 , such as one or more CPUs, microcontrollers, field programmable gate arrays, or other types of processors. Communication device  130  also includes system memory  138 , which may correspond to any combination of volatile and/or non-volatile storage mechanisms. The system memory  138  stores information that provides operating system components, various program modules, program data, and/or other components. In one embodiment, the system memory  138  stores instructions of methods to control the operation of the communication device  130 . The electronic device  130  performs functions by using the processor(s)  132  to execute instructions provided by the system memory  138 . For example, memory device(s)  138  may store interference data  140 . Interference data  140  may indicate a mapping of beamforming directions and registered interference status. For example, each direction may be mapped to a saturation status. A saturation status may indicate whether one or more components of RF chain  136  meet a saturation condition when receiving a signal along the corresponding angle. For example,  FIGS.  5 A-B  illustrate examples of interference data  140 . 
     Interference detection module  136  configures the RF chain (e.g., ABF and/or DBF devices) to receive signals in various directions. For example, the RF chain  136  may be configured to direct receive beams to receive signals at various beamforming angles. Receive beams may be directed using a weighting pattern across beamforming elements and an antenna array. The weighting pattern may result in a sensitivity pattern due to signal interference. An antenna gain pattern may include a weighting pattern (or distribution of signal processing weights) that may include a combination of beamforming values such as phase shifting values, signal amplifier values, etc. that are configured to steer a signal (e.g., main lobe, side lobes, null points, etc.) to orient along different directions. An antenna gain pattern may include a main lobe, side lobes, and nulls spread across various directions relative to a bearing angle of an antenna array. In some embodiment, a bearing angle is define as direction normal to a plane of an antenna array (or more generally a portion and an array antenna). Further details regarding beamforming and beam steering is discussed in  FIG.  2   . 
     The processing device  132  may direct the RF chain to receive signal  150  from communication device  110  by directing the receive beam along a direction towards a position of communication device  110 . Interference correction module  134  may determine a saturation condition (e.g., ADC clipping) of the RF chain  136  receiving a signal along a receive beam direction. The interference correction module  134  performs an interference survey to determine which receive beam directions cause the saturation condition to occur within the RF chain  136 . The results of the interference survey may be stored in memory device(s)  138  (e.g., interference data  140 ). Interference correction module  134  may determine a second direction to direct the receive beam (e.g., of RF chain  136 ) to receive signal  150 . Further details of the interference correction module  134  are discussed in  FIGS.  2 - 7   . 
     Although communication system  100  is illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, application-specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs), and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements of system  100  may refer to one or more processes operating on one or more processing elements. 
     Embodiments may be implemented in one or a combination of hardware, firmware, and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. In some embodiments, system  100  may include one or more processors and may be configured with instructions stored on a computer-readable storage device. 
       FIG.  2    is a functional diagram of a communication device  200  with analog beamforming (ABF) circuitry and digital beamforming (DBF) circuitry, according to embodiments of the present disclosure. The communication device  200  includes an RF chain  136  that includes antenna elements  202 , analog beamforming-front end module (ABF-FEM)  210 , and digital beamforming (DBF) module  220 . Antenna elements  202  are coupled to ABF-FEM  210 , such as through RF ports. The ABF-FEM  210  includes a low noise amplifier (LNA)  212  and an ABF device  214 . The LNA amplifies a low-power signal without significantly degrading the signal-to-noise (SNR) ratio. The ABF device  214  includes phase shifters that shift portions of received signal beams to align a phase of the received signal (e.g., signals received from the antenna elements  202 ) and combiners to combine the phase-aligned portions of the signal. The use of various power amplification values and phase shifter can effectively steer a receive beam of the antennas. For example, the antenna elements may be divided into multiple groups of distinct phases (e.g., four groups of antennas). It should be noted that  FIG.  2    is a simplified illustration and that components of ABF device  214  (e.g., phase shifters) may not be directly coupled to the RF ports. 
     The ABF-FEM  210  is coupled to DBF module  220 . DBF Module  220  includes an RF down conversion unit  222  coupled to ADC  224  and the DBF device  226 . Phase shifters can be implemented in a digital domain of the DBF device  226 . The phase shifters are coupled to a combiner. The combiner and phase shifters can be processing elements of the DBF device  226 , such as a discrete component, a discrete circuit, logic circuitry, a digital functional block, a programmable block, a digital signal processing (DSP) functional block, or the like. 
     In some embodiments, a signal beam is received across an antenna array by antenna elements  202 . The signal beam is transmitted through RF ports to ABF-FEM  210 . To arrive at the antenna elements  102 , the incoming signal beam may comprise variable path lengths to reach individual antenna elements  102  of the antenna array. The signal beam can be a primary beam made up of several subbeams that may or may not arrive from the safe direction. For example, subbeams of a signal beam propagating at 45 Degrees from nadir relative to the surface of the antenna array travel further to reach antenna elements  202  on a far side of the antenna array than to reach antenna elements on a near side of the antenna array relative to the incoming signal beam. The variable path length may result in the antenna elements  202  receiving the incoming signal beam in various phases across the antenna array. Each phase shifter receives subbeams of the signal from an associated antenna element  102 . A phase shifter applies a phase shift to the subbeams of the incoming signal. For example, phase shifters may apply a relative phase shift to each subbeam such that each signal of the total incoming signal is realigned to be in phase. The relative phase shift may be associated with the variable path length of the signal across each of the antenna elements  202 . The relative phase shift for an individual phase shifter  108  may be associated with the spatial location of an associated antenna element  202  of the antenna array. In some embodiments, the relative phase shift applied by the phase shifters may be associated with or coordinated with a time delay applied by ABF  214  and/or  226 . 
     The RF chain using beamforming components such as ABF and DBF use various antenna gain patterns having various weighting value for signal process elements such as phase shifter, signal amplifier, processing filters, etc. The antenna gain pattern may result in a receive beam or a distribution of sensitivities resulting in a main lobe, side lobe, and nulls across various direction from the array antenna. The various direction may be defined relative to a bearing angle of the array antenna. The bearing angle may be associated with a direction normal from a surface (or more generally a plane) of the array antenna. The various antenna gain patters can effectively steer the main lobe, side lobes, and nulls to be directed as various angle by adjusting the various weighting of the signal process elements, as discussed above. 
     In some embodiments, a phase shifter  108  is associated with multiple antenna elements  202 . For example, DBF device  226  and/or ABF device  214  may include one phase shifter coupled to receive signals from multiple antenna elements  102 . As noted above, the phase shifter is not necessarily coupled to an antenna element  102 . For example, there can be a down-conversion chain, including an analog-to-digital converter, before a signal gets to the phase shifter. Each phase shifter may shift the phase of signals received by multiple antenna elements  202 . In another example, a DBF device  226  and/or ABF  214  may include a phase shifter for each antenna element  202  such that each phase shifter is associated only with an individual antenna element  202  of the antenna array. 
     In some embodiments, combination of phase shifter values, amplifier values may be associated together into a weighted combination of values the effective steer a beam (e.g., main lobes, side lobes, null points). For example, a main lobe may be pointed at a target communication device or and offset of the target communication device. In radio electronics, a null is a direction in an antenna&#39;s radiation pattern where the antenna radiates or combines signal to almost no radio waves. For example, the far field signal strength is a local minimum. Nulls occur because different parts of an antenna radiate radio waves of different phase or the phase shifter phase compensate signal to cancel leading to a null. 
     The received signal may be phase-compensated both by the ABF device  214  and the DBF device  226  to generate the baseband signal  230 . The DBF module  220  and the ABF-FEM  210  may direct beams independent of each other (e.g., a digital beamforming direction and an analog beamforming direction). As described herein, signal interference may result in the DBF module experiencing a saturation condition (e.g., ADC  224  clipping) when a signal is received at a given direction. Steering the analog receive beam (e.g., by ABF  214 ) to a different angle may result in the saturation condition being remedied (e.g., the saturation condition is no longer present). In some embodiments, the beam direction is controlled across two dimensions. For example, the analog beam may be directed along an elevation angle (e.g., relative to a horizon) and an azimuth angle (e.g., parallel to the horizon). 
     In some embodiments, the DBF module includes multiple DBF chains (e.g., multiple ADCs). The saturation condition may occur when one of the ADC experiences saturation (e.g., clipping). In other embodiments, the saturation condition may correspond to a threshold number (e.g., threshold quantity) of ADCs experiencing saturation. Saturation generally refers to when the received signal power of the ADC operates outside an operational range of the ADC. 
       FIG.  3    depicts a hybrid beamforming interference correction process  300  corresponding to a communication device, according to embodiments of the present disclosure. Process  300  may be performed by processing elements that may comprise hardware (circuitry, dedicated logic, etc.), software (such as run on a general purpose computer system or a dedicated machine), or any combination thereof. In one implementation, the process  300  is performed on communication device  130  using processing device  132  of  FIG.  1   . In another implementation, process  300  may be performed using communication device  130 , respectively, while in some other implementations, one or more blocks of  FIG.  3    may be performed by one or more other machines not depicted in the figures. 
     At block  302 , processing logic directs a receive beam (e.g., analog and digital beams) towards a satellite (e.g., communication device  110  of  FIG.  1   ). When receiving the RF signal, aiming beams (e.g., analog and digital) towards the communication source can provide relatively positive SNR results. 
     At block  304 , processing logic determines an RF saturation event. As previously indicated, a communication device (e.g., a fixed service terrestrial device) may interfere with the reception of a downlink satellite communication by another communication device (e.g., a customer terminal (CT)). The saturation event may correspond to an ADC of the receiving communication device experiencing (e.g., reporting the saturation event to a controller or processing device) signal saturation (e.g., clipping, operating outside dynamic operable range). In some embodiments, the saturation event occurs when a threshold number of ADC devices (e.g., fifty percent of ADC clipped) report processing a signal outside the dynamic operable range. In some embodiments, the saturation event is determined based on data by the physical (PHY) layer of the underlying hardware. For example, the physical layer comprises the electronic circuit transmission technologies of a network. It is a fundamental layer underlying the higher-level function in a network and can be leveraged for various data (e.g., diagnostic data) that may indicate the saturation event. Processing logic may receive signal-interference-noise-ratio (SINK) data from the PHY layer. 
     At block  306 , processing logic scans an environment for interference. Scanning the environment includes steering the analog receive beam along various angles and determining whether the saturation event occurs when signals are received along the respective directions. In some embodiments, the various directions may be defined by an elevation angle (e.g., from the horizon) and an azimuth (e.g., relative to the target position of the satellite). Further details of the scanning process are discussed in  FIG.  4   . 
     At block  308 , processing logic generates an interference map. The interference map (or more generally interference data) indicates interference conditions (e.g., saturation conditions associated with various beamforming directions) of neighboring beamforming directions. In some embodiments, the interference map indicates a saturation status (e.g., a binary indicator of whether maintaining the corresponding beamforming direction results in the saturation event. In some embodiments, the interference map stores updated directions on how the communication device should direct the RF chain that does not experience the saturation event. For example, the interference data may indicate a direction the beamforming devices should direct the receive beam (e.g., that does not result in the saturation event). Further details regarding the interference map are discussed in conjunction with  FIGS.  5 A-B . 
     At block  310 , processing logic directs the receive beam towards the satellite in a first direction. The direction may be associated with an elevation angle and an azimuth angle. In some embodiments, the direction may be stored as a vector in any coordinates system such as, for example, Cartesian, cylindrical, spherical, and/or the like. 
     At block  312 , processing logic receives an RF signal while the receive beam is directed along the second direction. At block  314 , processing logic determines RF saturation corresponding to the first direction. At block  316 , processing logic causes the receive beam (analog beamforming) to a second direction using the interference map. For example, the second direction may be a location proximate to the first direction that does not experience the saturation event. 
       FIG.  4    depicts an interference map generation process  400 , according to embodiments of the present disclosure. Process  400  may be performed by processing elements that may comprise hardware (circuitry, dedicated logic, etc.), software (such as run on a general purpose computer system or a dedicated machine), or any combination thereof. In one implementation, the process  400  is performed on communication device  130  using processing device  132  of  FIG.  1   . In another implementation, process  400  may be performed using communication device  130 , while in some other implementations, one or more blocks of  FIG.  4    may be performed by one or more other machines not depicted in the figures. 
     At block  404 , processing logic configures a device (e.g., a CT) to perform the interference scan. As shown in  FIG.  4   , the initiation of the interference scan using interference survey logic  420  may be responsive to determining RF saturation. In some embodiments, the interference survey logic is performed on a scheduled cadence (e.g., every few minutes, hours, once a day, etc.). The interference survey logic  420  includes processing logic configuring a beam (e.g., phase shifter and/or signal amplifiers of ABF devices and/or DBF devices) to be directed along a direction (e.g., a first direction, a second direction, a third direction, and so on). At block  408 , processing logic determines whether a threshold signal saturation is met when the receive beam is directed along the current direction. At block  410 , processing logic records whether the saturation interference meets the threshold signal saturation (e.g., a threshold amount of ADCs receive a signal outside the dynamic operable range). 
     At block  412 , processing logic determines whether the environment is fully surveyed. The processing logic may determine that the environment is not fully surveyed, and processing logic may continue along the no path to block  406  where another direction is selected and used. The processing logic may determine the environment is fully surveyed and continue along path “yes” to block  414 . Processing logic may use a variety of conditions to determine whether the environment is fully surveyed. In some embodiments, the environment may be a pre-determined collection of direction such as, for example, a collection of angles (e.g., elevation angle, longitudinal, angle tangent to the horizon), a collection of vectors (e.g., Cartesian vectors, spherical vectors, cylindrical vectors, etc.). Processing logic may determine that an entirety of an environment may be scanned when data corresponding to each of the pre-determined collection of angles is measured and/or recorded. 
     In some embodiments, processing logic determines a boundary of the interference (e.g., see in  FIG.  5   ). For example, an interference map may generally include directions that experience the saturation event and directions that do not experience the saturation events. Directions targeted towards an interference device (e.g., fixed service terrestrial device) are more likely to experience the saturation event, and angles directed away from the interference device are less likely to experience the saturation event. The processing logic may determine that an environment is fully surveyed when the boundary between the presence of the saturation event and the absence of the saturation event is ascertained. 
     In some embodiments, processing logic determines that the environment is fully surveyed when a corrective direction is identified for every direction associated with the saturation event. For example, during a scanning process, one or more directions may be associated with the saturation event (e.g., the device experiences saturation conditions when the device direction a received beam along the corresponding direction). The interference survey logic  420  may continue to scan (e.g., loop) until a corrective direction is identified for each interference direction. 
     At block  414 , processing logic generates an interference map using the recorded data. The interference may include one or more features of interference maps  500 A-B of  FIGS.  5 A-B . In some embodiments, the interference map indicates an interference status associated with a direction of a beam. For example, the interference map may indicate whether direction a beam in a particular direction results in the receiving communication device experiencing a saturation event/condition. 
     In some embodiments, processing logic determines a corrective direction for every angle experiencing the saturation condition. The interference map may indicate the corrective direction and, alternatively or in addition to, a status of the saturation condition for each direction. For example, processing logic may access the interference map to check whether a corresponding angle corresponds to the saturation condition. In another example, processing logic may access the interference map to determine an updated direction to orient beamforming devices to receive a signal without experiencing the saturation condition. 
       FIGS.  5 A-B  illustrate interference maps  500 A-B indicating signal interference of a surrounding environment of a communication device, according to embodiments of the present disclosure. As shown in  FIG.  5 A , interference map  500 A illustrates the interference pattern from incoming fixed interference from interference location  510 . The various axes of the map indicate a corresponding direction, and the color (e.g., green and red) indicates a status of the interference at the associated first axis coordinate and the second axis coordinate. The first axis  504  indicates an elevation angle, and the second axis  502  indicates an azimuth angle corresponding to a direction a receive beam is directed to receive a signal. 
     Interference map  500 A illustrates interference from a main peak (e.g., region  508 ) of the interference source  510  and side lobe interference (e.g., regions  506 ) from interference source  510 . The darker red colors indicate corresponding receive beam directions where the saturation condition is present. The lighter green (e.g., region  512 ) indicates corresponding receive beam directions that do not result in the threshold condition being present. The interference map further illustrates vectors pointing between a direction experiencing the saturation condition and a direction not experiencing the saturation condition. In some embodiments, the vectors identify the closest beamforming direction (e.g., smallest directional change, smallest angle) to the beamforming direction experiencing the saturation condition. In some embodiments, the vectors indicate an updated beamforming direction that does not experience the saturation condition that has the best signal strength (e.g., RSSI, SNR, SIR, etc.). 
     As shown in  FIG.  5 B , the interference map  500 B may be represented as a matrix or an effective data structure equivalent. Interference map  500 B may include multiple dimensions that indicate coordinates to a beamforming direction. For example, a first dimension  534  may indicate an elevation angle (e.g., from a location of the signal receiving device), and a second dimension may indicate an azimuth (e.g., from a location of the signal receiving device). The values indicate a status of the interference at the corresponding location provided by the element location within the matrix. For example, the value may indicate a 1. The value 1 may represent that the saturation event is experienced by the signal receiving device when the signal is received at the corresponding elevation and azimuth associated with the element location within the matrix. The value 0 may represent that the saturation event is not experienced by the signal receiving device when the signal is received at the corresponding elevation and azimuth associated with the element location within the matrix. 
     In some embodiments, the interference data may be stored in a data structure having key value pairs. The key of each key value pair may correspond to a direction in radian coordinates (azimuth, elevation) and a value of each key pair corresponds to an indication (e.g., status) of a saturation condition or a non-saturation condition. In some embodiments, a non-saturation condition incorporates the opposite of the saturation condition. For example, a saturation condition may include determining a threshold number of DBF devices reporting a saturation event. The non-saturation condition may correspond to less than the threshold number of DBF devices reporting the saturation event. Corresponding non-saturation conditions may be defined for other saturation conditions and/or events as described herein. 
     As shown in  FIG.  5 A , the azimuth angle higher or lower to arrive at solution points (e.g., green intersections) and increase the elevation angle (e.g., 40 to 90 Degrees). 
       FIGS.  6 A-D  depict graphs  600 A-D illustrating the SNR degradation associated with terrestrial signal interference, according to embodiments of the present disclosure. Similar to many other interference cancellation technologies, canceling the interference can come with a cost. In this idea, beamforming gain is reduced when the CT steers its analog beam away from the target satellite. Below figure shows an analysis of the received SNR reduction. The black cross  610  in each of graphs  600 A-D represents the incoming direction of the fixed service interference (e.g., in azimuth and elevation angle). The contours with different shadings represent how much receive beam gain reduction results from steering the ABF beam away from the target satellite in a specific direction (e.g., azimuth and elevation). As shown in FIGS.  6 A-D, the cancellation cost is highly associated with the incoming direction of the fixed service. When interference comes from the horizon (e.g., elevation angle is about 0), the max receive beam gain reduction is around 4 dB and only applies to a small set of target satellite directions. When the fixed service interference comes from a high elevation angle, the max Receive beam gain reduction is relatively large (e.g., covering a majority of the sky). 
       FIG.  7    is a flow diagram of a method  700  for hybrid beamforming interference correction, according to embodiments of the present disclosure. Method  700  may be performed by processing elements that may comprise hardware (circuitry, dedicated logic, etc.), software (such as run on a general purpose computer system or a dedicated machine), or any combination thereof. In one implementation, method  700  is performed on communication device  130  using processing device  132  of  FIG.  1   . In another implementation, process  300  may be performed using communication device  130 , respectively, while in some other implementations, one or more blocks of  FIG.  7    may be performed by one or more other machines not depicted in the figures. 
     At block  704 , processing logic generates an interference map. Processing logic may cause a first communication device to orient beamforming circuitry to direct a main lobe of an antenna gain pattern along each of a set of directions. The set of direction may be associated with a surrounding region an expected position of a transmitting communication device (e.g. satellite). For example, the various direction may be associated with a travel path of the satellite in orbit and direction proximate the travel path. In some embodiments, processing logic, determines a status of a saturation condition (e.g., the saturation as define herein) corresponding to each of the set of directions. The status may indicate whether the corresponding direction results in RF saturation in corresponding signals associated with respective directions of the set of directions. In some embodiments, process logic may generate first data indicating the status of the saturation condition for each direction of the set of directions. In some embodiments, the interference map (e.g., first data) may include one or more features and/or details of interference maps  500 A and  500 B of  FIGS.  5 A and  5 B , respectively. 
     In some embodiments, processing logic causes an RF chain of a wireless device to direct a receive beam along a first direction corresponding to a first position of a second wireless device. The receive beam may be associated with a signal receiving device such as, for example, communication device  130  of  FIG.  1   . The second wireless device may include a satellite (e.g., performing a data downlink). 
     In some embodiments, processing logic receives a first RF signal by the first wireless device with the receive beam directed along the first direction. In some embodiments, the first RF signal is received as a part of a satellite downlink. In some embodiments, a portion of the first RF signal may be attributed to a third wireless device. For example, the third wireless device may include a fixed-service terrestrial device. 
     At block  706 , processing logic determines that a saturation condition is present in association with processing the first RF signal by the first wireless device. As previously indicated, the saturation condition may be present when an ADC of a communication device operates outside an operable dynamic range (e.g., ADC clipping and/or signal saturation). 
     At block  708 , processing logic retrieves first data indicating a set of directions of receive beams and corresponding statuses of the saturation condition. In some embodiments, processing logic may perform an environmental survey procedure to obtain the first data. Processing logic may cause the RF chain to direct the receive beam along each of the set of directions identified in the first data. Processing logic determines a status of the saturation condition corresponding to each of the set of directions. The status indicates whether the saturation is present when processing the signal associated with the RF chain directed along each of the set of directions. Processing logic generates the first data by storing the set of directions and corresponding status of the saturation condition in a data structure. 
     In some embodiments, the first data includes a matrix with a first dimension representative of the elevation angle, a second dimension representative of the azimuthal angle, and an element value representative of the status of the saturation condition associated with a corresponding elevation angle and a corresponding azimuthal angle. 
     At block  710 , processing logic determines, using the first data, a second direction corresponding to an absence of the saturation condition. The second direction may be provided in directional coordinates. For example, the second direction may be provided as an elevation angle and an azimuth angle (relative to the receiving wireless device). 
     At block  712 , processing logic causes the RF chain to direct the receive beam along the second direction. At block  714 , processing logic receives a second RF signal by the wireless device with the receive beam directed along the second direction. 
       FIG.  8    illustrates a portion of a communication system  800  that includes two satellites of a constellation of satellites  802 ( 1 ),  802 ( 2 ), . . . ,  802 (S), each satellite  802  being in orbit  804  according to embodiments of the present disclosure. The system  800  shown here comprises a plurality (or “constellation”) of satellites  802 ( 1 ),  802 ( 2 ), . . . ,  802 (S), each satellite  802  being in orbit  804 . Any of the satellites  802  can include the communication system  100  of  FIG.  1    or communication device  200  of  FIG.  2    and other array antennas and receiving (Rx) and/or transmission (Tx) DBF devices described herein. Also shown is a ground station  806 , a user terminal (UT)  808 , and a user device  810 . 
     The constellation may comprise hundreds or thousands of satellites  802 , in various orbits  804 . For example, one or more of these satellites  802  may be in non-geosynchronous orbits (NGOs) in which they are in constant motion with respect to the Earth. For example, the orbit  804  is a low earth orbit (LEO). In this illustration, orbit  804  is depicted with an arc pointed to the right. A first satellite (SAT1)  1302 ( 1 ) is leading (ahead of) a second satellite (SAT2)  802 ( 2 ) in the orbit  804 . 
     The satellite  802  may comprise a structural system  820 , a control system  822 , a power system  824 , a maneuvering system  826 , and a communication system  828 . In other implementations, some systems may be omitted, or other systems added. One or more of these systems may be communicatively coupled with one another in various combinations. 
     The structural system  820  comprises one or more structural elements to support the operation of the satellite  802 . For example, the structural system  820  may include trusses, struts, panels, and so forth. The components of other systems may be affixed to or housed by the structural system  820 . For example, the structural system  820  may provide mechanical mounting and support for solar panels in the power system  824 . The structural system  820  may also provide for thermal control to maintain components of the satellite  1302  within operational temperature ranges. For example, the structural system  820  may include louvers, heat sinks, radiators, and so forth. 
     The control system  822  provides various services, such as operating the onboard systems, resource management, providing telemetry, processing commands, and so forth. For example, the control system  822  may direct the operation of the communication system  828 . 
     The power system  824  provides electrical power to operate the components onboard the satellite  802 . The power system  824  may include components to generate electrical energy. For example, the power system  824  may comprise one or more photovoltaic cells, thermoelectric devices, fuel cells, and so forth. The power system  824  may include components to store electrical energy. For example, the power system  824  may comprise one or more batteries, fuel cells, and so forth. 
     The maneuvering system  826  maintains the satellite  802  in one or more of a specified orientation or orbit  804 . For example, the maneuvering system  826  may stabilize the satellite  802  with respect to one or more axis. In another example, the maneuvering system  826  may move the satellite  802  to a specified orbit  804 . The maneuvering system  826  may include one or more computing devices, sensors, thrusters, momentum wheels, solar sails, drag devices, and so forth. For example, the sensors of the maneuvering system  826  may include one or more global navigation satellite system (GNSS) receivers, such as global positioning system (GPS) receivers, to provide information about the position and orientation of the satellite  802  relative to Earth. In another example, the sensors of the maneuvering system  826  may include one or more star trackers, horizon detectors, and so forth. The thrusters may include, but are not limited to, cold gas thrusters, hypergolic thrusters, solid-fuel thrusters, ion thrusters, arcjet thrusters, electrothermal thrusters, and so forth. 
     The communication system  828  provides communication with one or more other devices, such as other satellites  802 , ground stations  806 , user terminals  808 , and so forth. The communication system  828  may include one or more modems, digital signal processors, power amplifiers, antennas (including at least one antenna that implements multiple antenna elements, such as a phased array antenna, and including an embedded calibration antenna, such as the calibration antenna  804  as described herein), processors, memories, storage devices, communications peripherals, interface buses, and so forth. Such components support communications with other satellites  802 , ground stations  806 , user terminals  808 , and so forth using radio frequencies within a desired frequency spectrum. The communications may involve multiplexing, encoding, and compressing data to be transmitted, modulating the data to a desired radio frequency, and amplifying it for transmission. The communications may also involve demodulating received signals and performing any necessary de-multiplexing, decoding, decompressing, error correction, and formatting of the signals. Data decoded by the communication system  828  may be output to other systems, such as the control system  822 , for further processing. Output from a system, such as the control system  822 , may be provided to the communication system  828  for transmission. 
     One or more ground stations  806  are in communication with one or more satellites  802 . The ground stations  806  may pass data between the satellites  802 , a management system  850 , networks such as the Internet, and so forth. The ground stations  806  may be emplaced on land, on vehicles, at sea, and so forth. Each ground station  806  may comprise a communication system  840 . Each ground station  806  may use the communication system  840  to establish communication with one or more satellites  802 , other ground stations  806 , and so forth. The ground station  806  may also be connected to one or more communication networks. For example, the ground station  806  may connect to a terrestrial fiber optic communication network. The ground station  806  may act as a network gateway, passing user data  812  or other data between the one or more communication networks and the satellites  802 . Such data may be processed by the ground station  806  and communicated via the communication system  840 . The communication system  840  of a ground station may include components similar to those of the communication system  828  of a satellite  802  and may perform similar communication functionalities. For example, the communication system  840  may include one or more modems, digital signal processors, power amplifiers, antennas (including at least one antenna that implements multiple antenna elements, such as a phased array antenna), processors, memories, storage devices, communications peripherals, interface buses, and so forth. 
     The ground stations  806  are in communication with a management system  850 . The management system  850  is also in communication, via the ground stations  806 , with the satellites  802  and the UTs  808 . The management system  850  coordinates the operation of the satellites  802 , ground stations  806 , UTs  808 , and other resources of the system  800 . The management system  850  may comprise one or more of an orbital mechanics system  852  or a scheduling system  856 . In some embodiments, the scheduling system  856  can operate in conjunction with an HD controller. 
     The orbital mechanics system  852  determines orbital data  854  that is indicative of a state of a particular satellite  802  at a specified time. In one implementation, the orbital mechanics system  852  may use orbital elements that represent characteristics of the orbit  804  of the satellites  802  in the constellation to determine the orbital data  854  that predicts location, velocity, and so forth of particular satellites  802  at particular times or time intervals. For example, the orbital mechanics system  852  may use data obtained from actual observations from tracking stations, data from the satellites  802 , scheduled maneuvers, and so forth to determine the orbital elements. The orbital mechanics system  852  may also consider other data, such as space weather, collision mitigation, orbital elements of known debris, and so forth. 
     The scheduling system  856  schedules resources to provide communication to the UTs  808 . For example, the scheduling system  856  may determine handover data that indicates when communication is to be transferred from the first satellite  802 ( 1 ) to the second satellite  802 ( 2 ). Continuing the example, the scheduling system  856  may also specify communication parameters such as frequency, timeslot, and so forth. During operation, the scheduling system  856  may use information such as the orbital data  854 , system status data  858 , user terminal data  860 , and so forth. 
     The system status data  858  may comprise information such as which UTs  808  are currently transferring data, satellite availability, current satellites  802  in use by respective UTs  808 , capacity available at particular ground stations  806 , and so forth. For example, the satellite availability may comprise information indicative of satellites  802  that are available to provide communication service or those satellites  802  that are unavailable for communication service. Continuing the example, a satellite  802  may be unavailable due to malfunction, previous tasking, maneuvering, and so forth. The system status data  858  may be indicative of past status, predictions of future status, and so forth. For example, the system status data  858  may include information such as projected data traffic for a specified interval of time based on previous transfers of user data  812 . In another example, the system status data  858  may be indicative of future statuses, such as a satellite  802  being unavailable to provide communication service due to scheduled maneuvering, scheduled maintenance, scheduled decommissioning, and so forth. 
     The user terminal data  860  may comprise information such as a location of a particular UT  808 . The user terminal data  860  may also include other information such as a priority assigned to user data  812  associated with that UT  808 , information about the communication capabilities of that particular UT  808 , and so forth. For example, a particular UT  808  in use by a business may be assigned a higher priority relative to a UT  808  operated in a residential setting. Over time, different versions of UTs  808  may be deployed, having different communication capabilities such as being able to operate at particular frequencies, supporting different signal encoding schemes, having different antenna configurations, and so forth. 
     The UT  808  includes a communication system  880  to establish communication with one or more satellites  802 . The communication system  880  of the UT  808  may include components similar to those of the communication system  828  of a satellite  802  and may perform similar communication functionalities. For example, the communication system  880  may include one or more modems, digital signal processors, power amplifiers, antennas (including at least one antenna that implements multiple antenna elements, such as a phased array antenna), processors, memories, storage devices, communications peripherals, interface buses, and so forth. The UT  808  passes user data  812  between the constellation of satellites  802  and the user device  810 . The user data  812  includes data originated by the user device  810  or addressed to the user device  810 . The UT  808  may be fixed or in motion. For example, the UT  808  may be used at a residence or on a vehicle such as a car, boat, aerostat, drone, airplane, and so forth. 
     The UT  808  includes a tracking system  882 . The tracking system  882  uses almanac data  884  to determine tracking data  886 . The almanac data  884  provides information indicative of orbital elements of the orbit  804  of one or more satellites  802 . For example, the almanac data  884  may comprise orbital elements such as “two-line element” data for the satellites  802  in the constellation that are broadcast or otherwise sent to the UTs  808  using the communication system  880 . 
     The tracking system  882  may use the current location of the UT  808  and the almanac data  884  to determine the tracking data  886  for the satellite  802 . For example, based on the current location of the UT  808  and the predicted position and movement of the satellites  802 , the tracking system  882  can calculate the tracking data  886 . The tracking data  886  may include information indicative of azimuth, elevation, distance to the second satellite, time of flight correction, or other information at a specified time. The determination of the tracking data  886  may be ongoing. For example, the first UT  808  may determine tracking data  886  every 1300 ms, every second, every five seconds, or at other intervals. 
     With regard to  FIG.  8   , an uplink is a communication link that allows data to be sent to a satellite  802  from a ground station  806 , UT  1308 , or a device other than another satellite  802 . Uplinks are designated as UL1, UL2, UL3, and so forth. For example, UL1 is a first uplink from the ground station  806  to the second satellite  1302 ( 2 ). In comparison, a downlink is a communication link that allows data to be sent from the satellite  802  to a ground station  806 , UT  808 , or device other than another satellite  802 . For example, DL1 is a first downlink from the second satellite  802 ( 2 ) to the ground station  806 . The satellites  802  may also be in communication with one another. For example, a crosslink  890  provides for communication between satellites  802  in the constellation. 
     The satellite  802 , the ground station  806 , the user terminal  808 , the user device  810 , the management system  850 , or other systems described herein may include one or more computer devices or computer systems comprising one or more hardware processors, computer-readable storage media, and so forth. For example, the hardware processors may include application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), microcontrollers, digital signal processors (DSPs), and so forth. The computer-readable storage media can include system memory, which may correspond to any combination of volatile and/or non-volatile memory or storage technologies. The system memory can store information that provides an operating system, various program modules, program data, and/or other software or firmware components. 
     In one embodiment, the system memory stores instructions of methods to control the operation of the electronic device. The electronic device performs functions by using the processor(s) to execute instructions provided by the system memory. Embodiments may be provided as a software program or computer program, including a non-transitory computer-readable storage medium having stored thereon instructions (in compressed or uncompressed form) that may be used to program a computer (or other electronic devices) to perform the processes or methods described herein. The computer-readable storage medium may be one or more of an electronic storage medium, a magnetic storage medium, an optical storage medium, a quantum storage medium, and so forth. For example, the computer-readable storage medium may include, but is not limited to, hard drives, floppy diskettes, optical disks, read-only memories (ROMs), random access memories (RAMs), erasable programmable ROMs (EPROMs), electrically erasable programmable ROMs (EEPROMs), flash memory, magnetic or optical cards, solid-state memory devices, or other types of physical media suitable for storing electronic instructions. Further embodiments may also be provided as a computer program product, including a transitory machine-readable signal (in compressed or uncompressed form). Examples of transitory machine-readable signals, whether modulated using a carrier or unmodulated, include, but are not limited to, signals that a computer system or machine hosting or running a computer program can be configured to access, including signals transferred by one or more networks. For example, the transitory machine-readable signal may comprise the transmission of software by the Internet. 
       FIG.  9    is a functional block diagram of some systems associated with the satellite  802 , according to some implementations. The satellite  802  may comprise a structural system  902 , a control system  904 , a power system  906 , a maneuvering system  908 , one or more sensors  910 , and a communication system  912 . A pulse per second (PPS) system  914  may be used to provide a timing reference to the systems onboard the satellite  802 . One or more busses  916  may be used to transfer data between the systems onboard the satellite  802 . In some implementations, redundant busses  916  may be provided. The busses  916  may include, but are not limited to, data busses such as Controller Area Network Flexible Data Rate (CAN FD), Ethernet, Serial Peripheral Interface (SPI), and so forth. In some implementations, the busses  916  may carry other signals. For example, a radio frequency bus may comprise a coaxial cable, waveguides, and so forth to transfer radio signals from one part of the satellite  802  to another. In other implementations, some systems may be omitted, or other systems added. One or more of these systems may be communicatively coupled with one another in various combinations. 
     The structural system  902  comprises one or more structural elements to support the operation of the satellite  802 . For example, the structural system  902  may include trusses, struts, panels, and so forth. The components of other systems may be affixed to or housed by the structural system  902 . For example, the structural system  902  may provide mechanical mounting and support for solar panels in the power system  906 . The structural system  902  may also provide for thermal control to maintain components of the satellite  802  within operational temperature ranges. For example, the structural system  902  may include louvers, heat sinks, radiators, and so forth. 
     The control system  904  provides various services, such as operating the onboard systems, resource management, providing telemetry, processing commands, and so forth. For example, the control system  904  may direct the operation of the communication system  912 . The control system  904  may include one or more flight control processors  920 . The flight control processors  920  may comprise one or more processors, FPGAs, and so forth. A tracking, telemetry, and control (TTC) system  922  may include one or more processors, radios, and so forth. For example, the TTC system  922  may comprise a dedicated radio transmitter and receiver to receive commands from a ground station  806 , send telemetry to the ground station  806 , and so forth. A power management and distribution (PMAD) system  924  may direct the operation of the power system  906 , control distribution of power to the systems of the satellite  802 , control battery  934  charging, and so forth. 
     The power system  906  provides electrical power to operate the components onboard the satellite  802 . The power system  906  may include components to generate electrical energy. For example, the power system  906  may comprise one or more photovoltaic arrays  930  comprising a plurality of photovoltaic cells, thermoelectric devices, fuel cells, and so forth. One or more PV array actuators  932  may be used to change the orientation of the photovoltaic array(s)  930  relative to the satellite  1802 . For example, the PV array actuator  932  may comprise a motor. The power system  906  may include components to store electrical energy. For example, the power system  906  may comprise one or more batteries  934 , fuel cells, and so forth. 
     The maneuvering system  908  maintains the satellite  802  in one or more of a specified orientation or orbit  804 . For example, the maneuvering system  908  may stabilize the satellite  802  with respect to one or more axes. In another example, the maneuvering system  908  may move the satellite  802  to a specified orbit  804 . The maneuvering system  908  may include one or more of reaction wheel(s)  940 , thrusters  942 , magnetic torque rods  944 , solar sails, drag devices, and so forth. The thrusters  942  may include, but are not limited to, cold gas thrusters, hypergolic thrusters, solid-fuel thrusters, ion thrusters, arcjet thrusters, electrothermal thrusters, and so forth. During operation, the thrusters may expend propellent. For example, an electrothermal thruster may use water as propellent, using electrical power obtained from the power system  906  to expel the water and produce thrust. During operation, the maneuvering system  908  may use data obtained from one or more of the sensors  910 . 
     The satellite  802  includes one or more sensors  910 . The sensors  910  may include one or more engineering cameras  950 . For example, an engineering camera  950  may be mounted on the satellite  802  to provide images of at least a portion of the photovoltaic array  930 . Accelerometers  952  provide information about the acceleration of the satellite  802  along one or more axes. Gyroscopes  954  provide information about the rotation of the satellite  802  with respect to one or more axes. The sensors  910  may include a global navigation satellite system (GNSS)  956  receiver, such as a Global Positioning System (GPS) receiver, to provide information about the position of the satellite  802  relative to Earth. In some implementations, the GNSS  956  may also provide information indicative of velocity, orientation, and so forth. One or more star trackers  958  may be used to determine an orientation of the satellite  802 . A coarse sun sensor  960  may be used to detect the sun, provide information on the relative position of the sun with respect to the satellite  802 , and so forth. The satellite  802  may include other sensors  910  as well. For example, the satellite  802  may include a horizon detector, radar, lidar, and so forth. 
     The communication system  912  provides communication with one or more other devices, such as other satellites  802 , ground stations  806 , user terminals  808 , and so forth. The communication system  912  may include one or more modems  976 , digital signal processors, power amplifiers, antennas  982  (including at least one antenna that implements multiple antenna elements, such as a phased array antenna such as the antenna elements  148  of  FIG.  1   ), processors, memories, storage devices, communications peripherals, interface buses, and so forth. Such components support communications with other satellites  802 , ground stations  806  user terminals  808 , and so forth using radio frequencies within a desired frequency spectrum. The communications may involve multiplexing, encoding, and compressing data to be transmitted, modulating the data to a desired radio frequency, and amplifying it for transmission. The communications may also involve demodulating received signals and performing any necessary de-multiplexing, decoding, decompressing, error correction, and formatting of the signals. Data decoded by the communication system  912  may be output to other systems, such as the control system  904 , for further processing. Output from a system, such as the control system  904 , may be provided to the communication system  912  for transmission. 
     The communication system  912  may include hardware to support the intersatellite link  890 . For example, an intersatellite link FPGA  970  may be used to modulate data sent and received by an ISL transceiver  972  to send data between satellites  902 . The ISL transceiver  972  may operate using radio frequencies, optical frequencies, and so forth. 
     A communication FPGA  974  may be used to facilitate communication between the satellite  802  and the ground stations  806 , UTs  808 , and so forth. For example, the communication FPGA  974  may direct the operation of a modem  976  to modulate signals sent using a downlink transmitter  978  and demodulate signals received using an uplink receiver  980 . The satellite  802  may include one or more antennas  982 . For example, one or more parabolic antennas may be used to provide communication between the satellite  802  and one or more ground stations  806 . In another example, a phased array antenna may be used to provide communication between the satellite  802  and the UTs  808 . 
       FIG.  10    illustrates the satellite  1000  including an antenna system  1012  that is steerable according to embodiments of the present disclosure. The satellite  1000  can include the communication system  100  or communication device  200  of  FIGS.  1  and  2   , as well as other array antennas and Tx DBF devices, as described herein. The antenna system  1012  may include multiple antenna elements that form an antenna and that can be mechanically or electrically steered individually, collectively, or a combination thereof. In an example, the antenna is a phased array antenna. 
     In orbit  804 , the satellite  1000  follows a path  1014 , the projection of which onto the surface of the Earth forms a ground path  1016 . In the example illustrated in  FIG.  10   , the ground path  1016  and a projected axis extending orthogonally from the ground path  1016  at the position of the satellite  1000 , together define a region  1020  of the surface of the Earth. In this example, the satellite  1000  can establish uplink and downlink communications with one or more of ground stations, user terminals, or other devices within the region  1020 . In some embodiments, the region  1020  may be located in a different relative position to the ground path  1016  and the position of the satellite  1000 . For example, the region  1020  may describe a region of the surface of the Earth directly below the satellite  1000 . Furthermore, embodiments may include communications between the satellite  1000 , an airborne communications system, and so forth. 
     As shown in  FIG.  10   , a communication target  1022  (e.g., a ground station, a user terminal, or a CT (such as an HD CT)) is located within the region  1020 . The satellite  1000  controls the antenna system  1012  to steer transmission and reception of communications signals to selectively communicate with the communication target  1022 . For example, in a downlink transmission from the satellite  1000  to the communication target  1022 , a signal beam  1024  emitted by the antenna system  1012  is steerable within an area  1026  of the region  1020 . In some implementations, the signal beam  1024  may include multiple subbeams. The extents of the area  1026  define an angular range within which the signal beam  1024  is steerable, where the direction of the signal beam  1024  is described by a beam angle “α” relative to a surface normal vector of the antenna system  1012 . In two-dimensional phased array antennas, the signal beam  1024  is steerable in two dimensions, described in  FIG.  15    by a second angle “β” orthogonal to the beam angle α. In this way, the area  1026  is a two-dimensional area within the region  1020 , rather than a linear track at a fixed angle determined by the orientation of the antenna system  1012  relative to the ground path  1016 . 
     In  FIG.  10   , as the satellite  1000  follows the path  1014 , the area  1026  tracks along the surface of the Earth. In this way, the communication target  1022 , which is shown centered in the area  1026  for clarity, is within the angular range of the antenna system  1012  for a period of time. During that time, signals communicated between the satellite  1000  and the communication target  1022  are subject to bandwidth constraints, including but not limited to signal strength and calibration of the signal beam  1024 . In an example, for phased array antenna systems, the signal beam  1024  is generated by an array of mutually coupled antenna elements, wherein constructive and destructive interference produce a directional beam. Among other factors, phase drift, amplitude drift (e.g., of a transmitted signal in a transmitter array), and so forth affect the interference properties and thus the resultant directional beam or subbeam. 
       FIG.  11    illustrates a simplified schematic of an antenna  1100 , according to embodiments of the present disclosure. The antenna  1100  may be a component of the antenna system  1012  of  FIG.  10   . As illustrated, the antenna  1100  is a phased array antenna that includes multiple antenna elements  1130  (e.g., antenna elements  148  in  FIG.  1   ). Interference between the antenna elements  1130  forms a directional radiation pattern in both transmitter and receiver arrays, forming a beam  1110  (beam extents shown as dashed lines). The beam  1110  is a portion of a larger transmission pattern (not shown) that extends beyond the immediate vicinity of the antenna  1100 . The beam  1110  is directed along a beam vector  1112 , described by an angle “θ” relative to an axis  1114  normal to a surface of the antenna  1100 . As described below, the beam  1110  is one or more of steerable or shapeable through control of operating parameters including, but not limited to, a phase and an amplitude of each antenna element  1130 . 
     In  FIG.  11   , the antenna  1100  includes, within a transmitter section  1122 , the antenna elements  1130 , which may include, but are not limited to, omnidirectional transmitter antennas coupled to a transmitter system  1140 , such as the downlink transmitter  1478 . The transmitter system  1140  provides a signal, such as a downlink signal to be transmitted to a ground station on the surface. The downlink signal is provided to each antenna element  1130  as a time-varying signal that may include several multiplexed signals. To steer the beam  1110  relative to the axis  1114 , the phased array antenna system  1100  includes antenna control electronics  1150  controlling a radio frequency (RF) feeding network  1152 , including multiple signal conditioning components  1154  interposed between the antenna elements  1130  and the transmitter system  1140 . The signal conditioning components  1154  introduce one or more of a phase modulation or an amplitude modulation (e.g., by phase shifters  216  in  FIG.  2   ), as denoted by “Δφ” in  FIG.  11   , to the signal sent to the antenna elements  1130 . As shown in  FIG.  11   , introducing a progressive phase modulation produces interference in the individual transmission of each antenna element  1130  that generates the beam  1110 . 
     The phase modulation imposed on each antenna element  1130  can differ and can be dependent on a spatial location of a communication target that determines an optimum beam vector (e.g., where the beam vector  1112  is found by one or more of maximizing signal intensity or connection strength). The optimum beam vector may change with time as the communication target  1022  moves relative to the phased array antenna system  1100 . 
     In the above description, numerous details are set forth. It will be apparent, however, to one of ordinary skill in the art having the benefit of this disclosure, that embodiments may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form rather than in detail in order to avoid obscuring the description. 
     Some portions of the detailed description are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to convey the substance of their work most effectively to others skilled in the art. An algorithm is used herein and is generally conceived to be a self-consistent sequence of steps leading to the desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. 
     It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as “determining,” “sending,” “receiving,” “scheduling,” or the like, refer to the actions and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (e.g., electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
     Embodiments also relate to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer-readable storage medium, such as, but not limited to, any type of disk including floppy disks, optical disks, Read-Only Memories (ROMs), compact disc ROMs (CD-ROMs), and magnetic-optical disks, Random Access Memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions. 
     The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear from the description below. In addition, the present embodiments are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the present embodiments as described herein. It should also be noted that the terms “when” or the phrase “in response to,” as used herein, should be understood to indicate that there may be intervening time, intervening events, or both before the identified operation is performed. 
     It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the present embodiments should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.