Mobile satellite beam collision cancellation

Abstract

The present disclosure describes methods, systems, and devices for mobile satellite beam collision cancellation. Communication services may be provided to a mobile terminal via respective beamformed spot beams that track movement of the mobile terminal. When a collision occurs between two beams, one of the beams may be handed over to the other resource to continue providing the communication service to its associated mobile terminal without beam-to-beam handover, thereby avoiding performance degradation and interruption associated with handover.

Description

Technical Field

[0001] The following relates generally to communications, including mobile satellite beam deconfliction. Background Art

[0002] Communication devices may communicate with each other using wired connections, wireless (e.g., radio frequency (RF)) connections, or both. Wireless communication between devices may be performed using radio spectrum designated for a service provider, a wireless technology, or both. In some examples, the amount of information that can be transmitted via a wireless communication network is based on the amount of radio spectrum designated for the service provider and the amount of frequency reuse within the area in which the service is provided. Satellite communications may use beamforming to establish beams to increase frequency reuse, however, providing high levels of frequency reuse in satellite communication systems using beamforming remains challenging. Summary of the Invention

[0003] The described technology relates to improved methods, systems, apparatuses, and devices that support mobile satellite beam conflict resolution. For example, communication services can be provided to a mobile terminal via corresponding beamforming spot beams that track the movement of the mobile terminal. When a conflict occurs between two beams, one of the beams can be switched to another resource, allowing communication services to continue to be provided to the associated mobile terminal via the corresponding beamforming spot beam without performing a beam-to-beam switch, thereby avoiding the performance degradation and interruption associated with the switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 An example of a satellite communication system supporting mobile satellite beam conflict cancellation according to examples described herein is shown.

[0005] Figure 2A and 2B An example of resources of a satellite communication system for supporting mobile satellite beam deconfliction according to examples described herein is shown.

[0006] Figure 3 An example of a satellite communication system supporting mobile satellite beam conflict cancellation according to examples as disclosed herein is shown.

[0007] Figure 4 An example of another satellite communication system supporting mobile satellite beam conflict cancellation according to examples as disclosed herein is shown.

[0008] Figure 5 An exemplary timing diagram is shown for supporting mobile satellite beam conflict resolution according to examples as disclosed herein.

[0009] Figure 6A block diagram illustrating a beam manager supporting mobile satellite beam conflict cancellation according to examples as disclosed herein.

[0010] Figure 7 A block diagram illustrating a terminal tracker supporting mobile satellite beam conflict cancellation according to examples as disclosed herein.

[0011] Figure 8 A flow chart illustrating a method of supporting mobile satellite beam conflict resolution according to examples as disclosed herein is shown. DETAILED DESCRIPTION

[0012] Beam-to-beam switching of a mobile terminal can be a source of disruption to the end user due to lost or delayed packets or changes in beam congestion levels or performance. In some satellite communication systems, beam-to-beam switching of a mobile terminal can be based on the relative position of the mobile terminal within adjacent fixed beams, which may not take into account interference between beams. For example, switching may occur when the mobile terminal is within an overlapping portion at the edge of the coverage area of ​​adjacent beams. At these locations, the mobile terminal may have a low signal-to-noise ratio (SNR) (for example, when compared to when the mobile terminal is at the center of the coverage area), resulting in reduced performance. To compensate, a lower coding rate can be set to provide more redundancy. However, this reduces the overall communication speed and is inefficient. In addition, all edge portions of the coverage area of ​​a beam must overlap with at least one of the other beams, requiring wide beams and significant beam overlap.

[0013] For a mobile terminal on a slow-moving vehicle (such as a car or a ship), handovers may occur relatively infrequently, and the resulting performance degradation and interruptions may have little overall impact on communications associated with the mobile terminal. However, for a mobile terminal on a fast-moving vehicle (such as an aircraft), performance degradation and interruptions caused by frequent beam-to-beam handovers may occur relatively frequently, thereby having a greater impact on communications. In either case, reducing the number of beam-to-beam handovers to reduce the resulting performance degradation and interruptions may be beneficial.

[0014] Techniques are described for performing beam deconfliction between beamforming spot beams that track a single mobile terminal while providing communication services to the mobile terminal via the beamforming spot beams. Deconfliction can be performed (e.g., rather than beam-to-beam switching of the mobile terminal), and can be based on conflicts (e.g., interference) between the beams. In some cases, beam deconfliction can be initiated when the interference level between the beams meets a threshold (e.g., reaches; exceeds; or reaches or exceeds a threshold). By doing so, rather than performing beam-to-beam switching, the frequency and number of beam-to-beam switches associated with the mobile terminal can be reduced, which can reduce the overall amount of performance degradation and the number of interruptions caused by switching. This can be particularly beneficial for mobile terminals on fast-moving vehicles (e.g., aircraft). Additionally, a single mobile terminal can use narrower beams compared to current systems, thereby allowing the use of more beams, which can increase overall capacity through spectrum reuse.

[0015] Aspects of the present disclosure are initially described in the context of satellite communication systems. Aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, block diagrams, and flow diagrams related to mobile satellite beam conflict cancellation.

[0016] Figure 1 An example of a satellite communication system 100 supporting mobile satellite beam deconfliction according to examples described herein is shown. Satellite communication system 100 may include a terrestrial network 135 and a satellite network 101 configured to track and provide communication services to one or more mobile terminals 120.

[0017] The terrestrial network 135 may include a set of earth stations 170 having access nodes 140 configured to communicate with the satellite network 101 via feeder links 132 (e.g., one or more satellite beams). The access nodes 140 may be coupled to access node transceivers 145 configured to process signals received from and to be transmitted by corresponding access nodes 140. The access node transceivers 145 may also be configured to interact with a network 125 (e.g., the Internet)—e.g., via a network device 130 (e.g., a network operations center, a satellite and gateway terminal command center, or other central processing center or device), which may provide an interface for communicating with the network 125.

[0018] The terrestrial network may also include a beam manager 175 for tracking mobile terminal 120 while providing communication services to the terminal. Beam manager 175 may use reference interrupts to associated beamforming spot beams, as described herein. For example, tracking a mobile terminal and performing conflict resolution between associated beams as discussed herein may be controlled by beam manager 175 using beams. Beam manager 175 may retrieve information (e.g., associated with satellite network 101 and terminal 120) from satellite network 101 (e.g., via feeder link 132 and access node 140) for use in performing control, and may send commands (e.g., to satellite network 101 and / or terminal 120) accordingly (e.g., via access node and feeder link).

[0019] Although depicted herein as a single device, beam manager 175 may alternatively be distributed throughout the system, for example, in various elements of the satellite network and / or the terrestrial network. For example, beam manager 175 may be incorporated into one or more devices of the terrestrial network (e.g., network device 130 or access node transceiver 145) or one or more devices of the satellite network (e.g., in a single satellite 105 or distributed across multiple satellites), or a combination of devices in the terrestrial and satellite networks. In some embodiments, a first portion of beam manager 175 may be located in terrestrial network 135, and a second portion may be located in satellite network 101.

[0020] Terminal 120 may include various devices configured to transmit signals using satellite network 101. Although terminal 120 is shown on an aircraft, terminal 120 may include a fixed terminal (e.g., a ground-based fixed terminal) or a mobile terminal mounted on a mobile platform (e.g., a ship, an aircraft, a ground-based vehicle, etc.), or a combination of fixed and mobile terminals. Terminal 120 may communicate data and information via satellite system 101 using access node 140. The data and information may be transmitted using a destination device (such as network device 130) or some other device or distributed server associated with network 125.

[0021] The satellite network 101 may include one or more satellites 105 (e.g., a single satellite or a network of satellites) deployed in space orbits (e.g., low earth orbit, medium earth orbit, geosynchronous orbit, geostationary orbit, etc.). Each satellite 105 included in the satellite network 101 may be equipped with one or more antennas (e.g., a single antenna or an antenna array). In some instances, one or more satellites 105 equipped with multiple antennas may each include one or more antenna panels that include an array of evenly distributed antennas (which may also be referred to as antenna elements). In some instances, a satellite may be equipped with an antenna array that includes antennas that are unevenly distributed across a large area. The ground network 135 may also include an access node 140 having multiple antenna array elements.

[0022] The terminal 120 may include an antenna assembly, which may also include various hardware for mounting the antenna. The antenna assembly may also include circuits and / or processors for performing conversions (e.g., performing frequency conversion, modulation / demodulation, multiplexing / demultiplexing, filtering, forwarding, etc.) between radio frequency (RF) satellite communication signals and satellite terminal communication signals transmitted between the antenna and the satellite terminal receiver. For a mobile terminal, the antenna assembly may be mounted external to the mobile platform (e.g., on the outside of the fuselage of an aircraft). Additionally or alternatively, the terminal 120 may include a transceiver, which may be mounted internally or externally to the mobile platform and may include circuits and / or processors for performing various RF signal operations (e.g., receiving; performing frequency conversion, modulation / demodulation, multiplexing / demultiplexing, etc.).

[0023] The satellite network 101 may have a large aperture size, which may be spanned by an antenna array or multiple satellites of the satellite network 101. The beam manager 175 may support beamforming techniques within the coverage area 155 of the satellite communication system using one or more satellites to increase the utilization of resources used for communication. The beam manager 175 may employ beamforming (including the use of multiple-input multiple-output (MIMO) techniques) to exploit multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals on the same frequency resources via different spatial layers. The beam manager 175 may cause the multiple signals to be transmitted, for example, by a transmitting device (e.g., satellite 105) via a set of antennas according to a set of weighting coefficients. Similarly, the multiple signals may be received by a receiving device (e.g., terminal 120) via a set of antennas according to a set of weighting coefficients. Each of the multiple signals may be associated with a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords).

[0024] In some instances, some or all antenna elements on satellite 105, ground network 135, and / or terminal 120 may be arranged to form arrays of receive and / or transmit feed elements that cooperate to implement various instances of onboard beamforming (OBBF), ground-based beamforming (GBBF), end-to-end beamforming, or other types of beamforming. In GBBF implementations, multiple transmit or receive antennas may be present at a ground system access node.

[0025] Beam manager 175 may determine weighting coefficients applicable to a group of antennas. For example, for N spatial layers to be formed, beam manager 175 may utilize an (M x N) MIMO matrix, where M may represent the number of antennas in a group of antennas. In some instances, M may be equal to N. Beam manager 175 may determine a MIMO matrix based on a channel matrix and may use the MIMO matrix to isolate different spatial layers of a channel. In some instances, beam manager 175 may select weighting coefficients to emphasize signals transmitted using different spatial layers while reducing interference from signals transmitted in other spatial layers. Thus, processing a signal received at each antenna in a group of antennas (e.g., signals received at a group of antennas) using a MIMO matrix may result in the output of multiple signals, each of which may correspond to one of the spatial layers. In some instances, the weighting coefficients used for MIMO communication may be referred to as beam coefficients or beamforming coefficients, and the multiple spatial layers may be referred to as beams or spot beams.

[0026] The beam manager 175 may determine the elements of the MIMO matrix for forming the spatial layer of the channel based on the channel sounding probes. The channel sounding probes may include reference signals that are periodically transmitted between the satellite network 101 and a device coupled to the satellite network (e.g., terminal 120). For example, the channel sounding probes may be periodically transmitted from the terminal 120 to the satellite 105, or from the satellite to the terminal, or both, and may include a sequence known to the transmitter and receiver (e.g., based on a terminal identifier or other parameter known to the transmitter and receiver). A receiving device (e.g., a terminal or satellite) may use the received channel sounding probes to evaluate the connection by correlating the received channel sounding probes with an expected signal of the channel sounding probes (e.g., to determine signal strength, interference, etc.) and make decisions based thereon. Due to the periodicity of the signal, the receiving device may know when the signal should be received.

[0027] The beam manager 175 can use beamforming techniques to shape and steer communication beams along spatial paths between one or more satellites within a geographic region and the mobile terminal 120. The beam manager 175 can cause the communication beam to be formed by determining weighting coefficients for antenna elements of an antenna array, the weighting coefficients causing signals transmitted from or received at the antenna elements to be combined such that signals propagating in a particular orientation relative to the antenna array experience constructive interference, while others experience destructive interference. Thus, beamforming can be used to transmit signals with energy focused in the direction of the communication beam and to receive signals arriving in the direction of the communication with increased signal power (relative to the absence of beamforming). The beam manager 175 can use the weighting coefficients to apply amplitude offsets, phase offsets, or both to signals carried via the antennas.

[0028] In some examples, the beam manager 175 may apply weighting coefficients to the antennas to form multiple beams, each associated with a different direction, where the multiple beams can be used to simultaneously convey multiple signals having the same frequency to different user terminals. This may be referred to as multi-user MIMO. The weighting coefficients used for beamforming may be referred to as beam coefficients, and the multiple signals may be referred to as beam signals. The resulting beam may be referred to herein as a beamformed spot beam, spot beam, or beam.

[0029] The beam manager 175 can calculate the amplitude and phase of each weighting coefficient given the antenna array and reflector geometry and position and the desired beam position. However, such an approach may be impractical due to inaccuracies (e.g., in satellite position, array orientation, geometry, atmospheric scintillation effects, etc.). Instead, the beam manager 175 can calculate the weighting coefficients using continuous or periodic measurements of MIMO propagation channel characteristics (e.g., paired channels from each system antenna element to each terminal antenna element) and adjust the weighting coefficients based on the changing channel characteristics. The measured MIMO channel characteristics may include paired gain and phase response and noise level and may be referred to as MIMO channel state information (CSI). Once the MIMO CSI is obtained, the beam manager 175 can derive the weighting coefficients by solving a set of equations or applying a set of adaptation formulas. Various beamformer calculation and adaptation techniques may be used, including minimum mean square (MMSE) beamformers, zero-forcing beamformers, MIMO sphere decoders, etc.

[0030] The measurement of MIMO CSI can include the cooperation of at least one terminal for each beam. The situation may be different in the forward link direction (from satellite to terminal) and the return link direction (from terminal to satellite). In the return link, each terminal can transmit a channel sounding signal, which can be orthogonal to the sounding signals of other terminals. The satellite can determine which channel sounding signal is transmitted from each terminal and can process the signal to estimate the channel parameters of the channel corresponding to that terminal. Therefore, the MIMO CSI on the return link can be calculated locally on the satellite side for the terminal that transmits the channel sounding signal. In contrast, on the forward link, the satellite can transmit a channel sounding signal. Different antenna elements can transmit signals that are orthogonal to each other. Each terminal that wants to calculate MIMO CSI can do so by processing the sounding signal corresponding to each transmit antenna element. In addition, each such terminal can transmit the MIMO CSI back to the satellite using the return link control channel.

[0031] The spot beams generated in this manner can be tailored to the MIMO CSI provided by the user terminals, and each beam can illuminate the direction of each such terminal. Each beam has a limited coverage area 160 (e.g., a few kilometers in diameter) and can therefore illuminate additional terminals that may be near the CSI generating terminal. These additional terminals may not be able to provide CSI because this may unnecessarily increase the CSI reporting channel overhead. The terminal used to provide per-beam MIMO CSI can be considered a reference terminal for that beam. In some instances, the coverage area 160 of a beam can be determined based on the wavelength of the carrier and the diameter of the aperture. The coverage area 160 can, for example, correspond to a footprint where the power level of the beam is above a threshold or where the power level drops by less than a threshold amount (e.g., 3 decibels (dB) or 6 dB) away from the center of the beam. In some instances, the coverage area 160 can be based on the beamwidth of the beam.

[0032] In some instances, one or more aircraft-based terminals 120 may be sufficiently separated in distance from each other and other aircraft so that the beam manager 605 can use a separate beam for each of the one or more terminals. In some instances, two or more of the terminals 120 may be in close proximity (e.g., at an airport) so that the beam manager 605 can illuminate the terminals with the same beam. In the former case, each terminal on the aircraft may be a reference terminal for its beam, while in the latter case, one of several terminals on the aircraft may serve as the reference terminal for the beam.

[0033] As the mobile terminal 120 moves in the spatial domain, the MIMO CSI may change, causing the direction of the beam to change. The beam manager 175 can adjust the beam direction based on the changing MIMO CSI so that the reference terminal can remain at or near the center of the beam. Thus, as the reference terminal moves, the beam can follow its movement, as further explained herein.

[0034] The beam manager 175 can associate a beamformed spot beam with a set of resources of the satellite communication system 100. A set of resources can include, for example, frequency resources, time resources, and polarization resources. For example, a given frequency range 100 of the satellite communication system can include frequency resources or channels, and a given amount of time can include different repeating time slots. For example, the beam manager 175 can use a frequency channel to carry a signal (e.g., a modulated signal carried in a beamformed spot beam) in one of the repeating time slots. By doing so, the beamformed spot beams can overlap spatially without interfering if they are associated with different frequency / time resource combinations. Furthermore, the beam manager 175 can use multiple polarizations so that two beamformed spot beams can overlap spatially without interfering if they are associated with different polarizations. Thus, beamformed spot beams can overlap spatially without interfering if they are associated with different combinations of resources (e.g., frequency channel / time slot / polarization combinations). The different combinations can be referred to as resource elements, which together form a set of resource elements that can be used by the beam manager 175 to convey signals via the beam. The beam manager 175 may control the association of beams with resource elements and when to reallocate beams, as discussed herein.

[0035] As described herein, the beam manager 175 can adjust a single coverage area or footprint of a beamforming spot beam (e.g., by adjusting weighting coefficients) to track a corresponding mobile terminal (e.g., a reference terminal) (e.g., to move in a coordinated manner with the corresponding mobile terminal). This can allow communication services associated with the mobile terminal to be provided via the same beamforming spot beam as the mobile terminal moves through the coverage area of ​​the satellite communication system. This can reduce the number of beam-to-beam switches for the mobile terminal, thereby reducing performance degradation and communication interruptions that may be caused by beam-to-beam switches. For example, beam-to-beam switches may require the beam-switching terminal to coordinate with the beam of the receiving terminal, which may require communication across several communication layers to transmit terminal information between access points (e.g., gateways, gateway modems) serving the beam and verify the transmission. This may result in performance degradation and communication interruptions between beams.

[0036] When beam tracking a mobile terminal, conflicts may occasionally occur between beams, such as when two movable beamforming spot beams overlap spatially while using the same resource element (e.g., the same frequency channel, time slot, polarization). However, these conflicts can be resolved using the conflict resolution procedures discussed herein. For example, when such a conflict occurs (e.g., based on an interference metric between beams meeting a threshold), the beam manager 175 can cause one of the conflicting mobile terminals to be moved to a different resource element. As a result, little or no performance degradation may result. And because conflict resolution may involve only a single beam (e.g., no communication across access points serving different beams), communication interruptions associated with switching between beams can be avoided.

[0037] Furthermore, as the reference terminals move, they can remain centrally located within the coverage area of ​​the beam. This can allow the SNR of the reference terminals to remain high, so that the overall communication speed and efficiency associated with the reference terminals can also be high.

[0038] Figure 2A An example of resources 200-a of a satellite communication system for supporting mobile satellite beam deconfliction according to examples described herein is shown. Resources 200-a can correspond to frequency partitions of the satellite communication system. For example, a frequency range 205 (e.g., a frequency band) can include a set of different frequency resources or frequency channels 210 (e.g., frequency channel 210-a, frequency channel 210-b, frequency channel 210-c, frequency channel 210-d) that carry signals between a satellite network and a terminal. Resources 200-a can correspond to frequency channels 210 of frequency range 205.

[0039] Each frequency channel 210 can carry a signal associated with a single terminal (e.g., once). For example, each frequency channel 210 can carry a single modulated signal. Information (e.g., data, control information) can be modulated onto the modulated signal using various single-carrier or multi-carrier modulation techniques (e.g., orthogonal frequency division multiplexing (OFDM), direct sequence spread spectrum (DSSS), linear precoded OFDM (LP-OFDM)). Beamforming spot beams can be associated with one or more frequency channels 210 (e.g., by beam manager 175) to provide communications to and track mobile terminals, as discussed herein.

[0040] exist Figure 2A In the example of FIG, resource 200-a may correspond to frequency channel 210. That is, each frequency channel 210 may be a separate resource 200-a. Because there are no other types of resources, in some examples, the separate resources may also be resource elements. Therefore, in this example, the number of available resource elements may correspond to the number N of frequency channels.

[0041] Figure 2B An example of a resource element 250 for a satellite communication system supporting mobile satellite beam conflict cancellation according to examples described herein is shown. In this example, frequency channel 210 can be reused to carry signals associated with a terminal. Additionally, frequency channels 210 can be time multiplexed. That is, each frequency channel 210 can be configured to carry a signal to a terminal in a time slot that repeats after a period of time. For example, time period 215 can be divided into a set of sub-periods or time slots t (e.g., time slot t1, time slot t2, time slot t3, time slot t4, etc.). m ), each having a length 225. Each frequency channel 210 can carry a signal to another terminal during each time slot t, although in some cases, multiple time slots within time period 215 can be allocated to the same terminal. For example, each frequency channel 210 can carry a single modulated signal during each time slot t. Information (e.g., data, control information) can be modulated on the modulated signal using various single-carrier or multi-carrier modulation techniques (e.g., OFDM, DSSS, LP-OFDM) to provide communication to and tracking of mobile terminals (e.g., via beam manager 175), as discussed herein.

[0042] Upon completion of time period 215, the process can be repeated such that each frequency channel 210 can carry additional signals associated with different terminals in the resource period. Thus, beam manager 175 can communicate with a terminal in one time slot t of each time period 215 using frequency channel 210. In some instances, beam manager 175 can assign a terminal to more than one time slot per time period, and thus communication with the terminal can occur in more than one time slot per time period for frequency channel 210.

[0043] exist Figure 2B In the example of , resource element 250 may correspond to a combination of frequency channel 210 and time slot t in time period 215. That is, each unique combination of frequency channel 210 and time slot t may be a separate resource element 250. Thus, in this example, the number of available resource elements may correspond to the number of frequency channels multiplied by the number of time slots, or N x m. Thus, with Figure 2A This instance can provide more resource elements than the instance of .

[0044] In addition to multiplexing in time or frequency, resource elements for allocation to beamforming spot beams may also be defined using different polarizations. For example, a set of resource elements may include a first subset of resource elements associated with a first polarization and a second subset of resource elements associated with a second orthogonal polarization. The first and second polarizations may be orthogonal polarizations and may be linearly polarized or circularly polarized (e.g., right-hand circular polarization (RHCP), left-hand circular polarization (LHCP)). Thus, a set of resource elements available for allocation to beamforming spot beams by the beam manager 175 may be defined based on frequency resources (e.g., frequency channels), time resources (e.g., sub-periods of a resource period), or polarization resources.

[0045] In some instances, resource element types may be combined. For example, in the same system, one or more frequency channels may be divided into time slots (e.g., Figure 2B ), and one or more other frequency channels may be used as, divided into (e.g., Figure 2A ) are separate resource elements. Other combinations are also possible.

[0046] Figure 3 An example of a satellite communication system 300 supporting mobile satellite beam conflict cancellation according to an example disclosed herein is shown. The satellite communication system 300 may be a reference Figure 1 1 or aspects thereof. The satellite communication system 300 may include a satellite network 101 having one or more satellites 105 configured to generate beamformed spot beams 150 (e.g., beam 150-a) for communicating with a set of terminals 120 (e.g., terminals 120-a, 120-b, 120-c, 120-d) within a coverage area 155 of the satellite communication system, as directed by a beam manager 175. The beamformed spot beams may be referred to herein as spot beams or beams.

[0047] Terminal 120 may be located on a movable platform or vehicle (such as a car, a boat, or an aircraft) and may therefore be considered a mobile terminal 120. In some instances, each vehicle may include a single mobile terminal. In other instances, one or more vehicles may each include two or more mobile terminals. At least some of mobile terminals 120 may be multi-user mobile terminals, and thus satellite communication system 300 may provide communication services to multiple user devices (e.g., smartphones, laptops, tablets) connected via mobile terminals 120.

[0048] In some examples, the satellite communication system 300 can provide communication services to the mobile terminal 120 via a set of movable beamforming spot beams 150 that track the mobile terminal during its movement as controlled by the beam manager 175. For clarity, Figure 3 Only a single movable beamforming spot beam 150-a associated with a single mobile terminal 120-a is shown in FIG. Figure 3 , but the movable beamforming spot beam 150 may also be associated with one or more of the other mobile terminals 120.

[0049] In some instances, the beam manager 175 may associate each beamforming spot beam 150 with a different mobile terminal 120. Each mobile terminal 120 associated with its own spot beam may be referred to as a reference terminal. Each spot beam 150 may have a corresponding coverage area 160 (e.g., coverage areas 160-a, 160-b, 160-c, 160-d). The coverage area may, for example, correspond to a footprint where the power level of the beam is above a threshold or where the power level drops by less than a threshold amount (e.g., 3 dB or 6 dB) away from the center of the beam.

[0050] In some examples, the beamforming spot beam associated with the reference terminal can be formed (e.g., as controlled by beam manager 175) to include the physical location of the terminal within the coverage area of ​​the beamforming spot beam. Figure 3 As shown, mobile terminal 120-a, acting as a reference terminal, may be physically located within coverage area 160-a of beamforming spot beam 150-a, and mobile terminals 120-b, 120-c, and 120-d may be physically located within coverage areas 160-b, 160-c, and 160-d of their respective beamforming spot beams (not shown). Satellite communication system 300 may provide communication services to mobile terminal 120-a via beamforming spot beam 150-a (e.g., via beam manager 175).

[0051] In some examples, the beam manager 175 can cause a beamforming spot beam to track a moving mobile terminal while providing communication services to the terminal via the beam. For example, as the mobile terminal 120-a physically moves from location A to location B, as indicated by arrow 325, the beamforming spot beam 150-a can "move" to track the mobile terminal, as indicated by arrow 330. In some examples, to "move" the beamforming spot beam, the beam manager 175 can modify the beamforming coefficients associated with the beamforming spot beam and apply them to the signal associated with the beamforming spot beam. This can change the directionality of the beamforming spot beam (e.g., "move" the beam), causing the coverage area of ​​the beamforming spot beam to change (e.g., "move").

[0052] To follow or track a mobile terminal, the beamforming coefficients may be modified by the beam manager 175 so that the coverage area of ​​the beamforming spot beam may move to reflect the movement of the mobile terminal (e.g., may move in a coordinated manner therewith). The beam manager 175 may continually adjust the coverage area (e.g., by periodically modifying the beamforming coefficients to provide continuous coverage) to continue to correspond to the moving physical location of the moving mobile terminal and thereby track the mobile terminal. For example, the beam manager 175 may move the coverage area 160-a of the beamforming spot beam 150-a (e.g., from coverage area 160-a1 to coverage area 160-a2) so as to encompass the physical location of the mobile terminal 120-a as the mobile terminal 120-a moves from location A to location B. This may allow communication services associated with the mobile terminal to be provided via the same beamforming spot beam as the mobile terminal moves through the coverage area of ​​the satellite communication system. For example, the beam manager 175 may provide continuous communication service to the mobile terminal 120 - a via the beamformed spot beam 150 - a without requiring handoff as the mobile terminal moves between location A and location B.

[0053] In some instances, the beam manager 175 can avoid changing the beamforming coefficients associated with a mobile terminal when the mobile terminal is stationary because the coverage area of ​​the beamforming spot beam may already correspond to the physical location of the stationary terminal. In other instances, the beam manager 175 can change the beamforming coefficients even when the mobile terminal is stationary. For example, in some systems, there may be a single set of beamforming coefficients that can generate all beams from all beam signals. In those cases, the beam manager 175 may change the beamforming coefficients for all terminals even if only one terminal is moving.

[0054] In some instances, to track a mobile terminal, beam manager 175 may adjust the coverage area of ​​a spot beam (e.g., move the spot beam) based on measurements of signals transmitted by the mobile terminal. In some instances, a terminal may provide channel state information back to the satellite network on a regular and periodic basis, and beam manager 175 may process the channel state information to calculate appropriate beamforming coefficients such that the beam energy of a beam signal associated with an aircraft is focused on the aircraft. As the aircraft moves, the channel state information may change, which in turn may cause changes in the beam weight coefficients calculated by beam manager 175. Through this beamformer adaptation process, the beam center may be continuously co-located with the aircraft position (possibly following the aircraft).

[0055] Additionally, the beam manager 175 can make an initial estimate of where to move the beam based on the mobile terminal's most recent speed and direction of travel. In some instances, the beam manager 175 can move the spot beam in such a way that the mobile terminal remains centrally located within the coverage area as the mobile terminal moves. This can allow the SNR for the mobile terminal to remain high, so that the overall communication speed and spectral efficiency associated with the mobile terminal can also be high.

[0056] In some examples, the beam manager 175 can determine the location of the mobile terminal based on information received from the mobile terminal, such as location coordinates (e.g., determined via a positioning system such as GPS), speed, direction, or other information associated with the mobile terminal. In some examples, the beam manager 175 can determine the location of the mobile terminal based on information external to the mobile terminal, such as based on radar or other signals.

[0057] In some instances, a satellite communication system may provide communication services to one or more mobile terminals via beamforming spot beams associated with the terminals. Figure 3 , the beam manager 175 can establish a beamforming spot beam 150 for each of the mobile terminals 120-a, 120-b, 120-c and 120-d, and can provide communication services to the mobile terminals and track the mobile terminals as the mobile terminals move within the coverage area 155 of the satellite communication system.

[0058] In some examples, beam manager 175 can use initial channel state information to determine the location of a mobile terminal. Beam manager 175 can determine the initial channel state information based on a measurement (e.g., signal strength) of an initial signal transmitted by (e.g., transmitted to or received from) the mobile terminal. The initial channel state information can be based on a corresponding first location of the mobile terminal within coverage area 155 (e.g., location A of mobile terminal 120-a). In some examples, the initial signal can include a corresponding initial channel sounding probe transmitted by the mobile terminal.

[0059] In some examples, to generate beamformed spot beams, beam manager 175 may apply beamforming coefficients to convert between beam signals associated with each of the beamformed spot beams and component signals associated with a plurality of antenna elements of the satellite communication system. For example, to generate a spot beam for transmitting information to a mobile terminal, beam manager 175 may apply beamforming coefficients to the beam signal (which contains the information) to obtain component signals that may be applied to the antenna elements; to generate a spot beam for receiving information from a mobile terminal, beam manager 175 may apply beamforming coefficients to the component signals received from the mobile terminal at the antenna elements to obtain beam signals containing the information.

[0060] The plurality of antenna elements may be located on one or more of the satellites 105, or may be located on components of a ground network (not shown) of the satellite communication system 300 (e.g., Figure 1 1 , the access node 140 of the terrestrial network 135. The beam manager 175 can use the beamforming coefficients to form a beamformed spot beam 150 between the satellite 105 and the coverage area 160. The beam manager 175 can base the beamforming coefficients on the initial channel state information so that the coverage area 160 of the beam 150 can cover the corresponding first location (e.g., location A) of the associated terminal 120.

[0061] The beamforming spot beams 150 may be forward link beamforming spot beams (e.g., for transmitting information to a mobile terminal) and / or return link beamforming spot beams (e.g., for receiving information from a mobile terminal). For example, the beamforming coefficients may include multiple sets of forward link beamforming coefficients and multiple sets of return link beamforming coefficients.

[0062] The beam manager 175 may apply a first set of forward link beamforming coefficients to a set of forward link beam signals at a first time to generate a first set of forward link component signals for transmission to one or more mobile terminals via the antenna elements at a first time. Transmitting the first set of forward link component signals to the mobile terminals via the antenna elements may first form forward link beamforming spot beams, each corresponding to one of the mobile terminals.

[0063] The beam manager 175 may apply a second set of forward link beamforming coefficients to a set of forward link beam signals at a second time to generate a second set of forward link component signals for transmission to the mobile terminal via the antenna elements at the second time. Transmission of the second set of forward link component signals to the mobile terminal via the antenna elements may form forward link beamforming spot beams for a second time, each corresponding to one of the mobile terminals. One or more of the forward link beamforming spot beams at the second time may have moved from the corresponding forward link beamforming spot beam at the first time to track movement of the corresponding mobile terminal.

[0064] On the return link, the beam manager 175 may apply a first set of return link beamforming coefficients to the return link component signals received from the mobile terminals via the antenna elements at the first time. Applying the first set of return link beamforming coefficients may form return link beamforming spot beams for the first time, each corresponding to one of the mobile terminals.

[0065] The beam manager 175 may apply a second set of return link beamforming coefficients to the return link component signals received from the mobile terminal via the plurality of antenna elements at the second time. Applying the second set of return link beamforming coefficients may form return link beamforming spot beams for a second time. One or more of the return link beamforming spot beams at the second time may have moved from the corresponding return link beamforming spot beam at the first time to track the movement of the corresponding mobile terminal.

[0066] In some examples, beam manager 175 can use subsequent channel state information to determine a subsequent location of the mobile terminal. Beam manager 175 can determine the subsequent channel state information based on measurements (e.g., signal strength) of subsequent signals transmitted by the mobile terminal. The subsequent channel state information can be based on a corresponding second location of the mobile terminal within coverage area 155 (e.g., location B of mobile terminal 120-a). The difference between the initial channel state information and the subsequent channel state information can be based on movement of the mobile terminal to the corresponding second location.

[0067] In some examples, the subsequent signal may include a corresponding subsequent channel sounding probe transmitted by the mobile terminal. The modification to the beamforming coefficients may be based on the corresponding subsequent channel sounding probe. In some examples, the corresponding initial and subsequent channel sounding probes may be communicated by the mobile terminal at a first periodicity, and the beamforming coefficients may be updated based thereon at a second periodicity.

[0068] In some examples, the beam manager 175 can modify the beamforming coefficients and apply them to convert between the beam signal and the component signals associated with the plurality of antenna elements of the satellite network. The modified beamforming coefficients can be based on subsequent channel state information so that the new coverage area of ​​the beam (e.g., coverage area 160-a2) can encompass the corresponding second location of the mobile terminal (e.g., location B).

[0069] The beam manager 175 may repeat the determination of subsequent positions of the mobile terminal and the modification of the beamforming coefficients based thereon (as often as needed and for as long as needed). In this manner, the plurality of beamforming spot beams 150 may track the movement of the reference terminal 120 throughout the coverage area 155 of the satellite communication system while providing communication service to the mobile terminal. In some examples, the beam manager 175 may move the beamforming spot beams 150 to track their respective mobile terminals frequently enough so that the associated coverage area at the current location may overlap with the coverage area at the previous location. That is, each movement of the beamforming spot beam 150 may move the beam by less than the diameter of the beamforming spot beam 150 (e.g., a radius or a portion thereof, such as half a radius).

[0070] In some instances, the beamforming coefficients (e.g., initial beamforming coefficients and all modified beamforming coefficients) may include multiple sets of beamforming coefficients. For a set of beamforming spot beams, each set of beamforming coefficients may correspond to a different time period. In some instances, the beamforming coefficients may be modified based on a characteristic, attribute, or condition satisfying (e.g., reaching, exceeding, and / or falling below) a threshold. For example, the beam manager 175 may modify and apply the beamforming coefficients based on received signal quality (e.g., measured at a reference terminal or at a satellite communication system) falling below a threshold. This may allow the signal quality associated with the mobile terminal to remain high, such that the overall communication speed and efficiency associated with the mobile terminal may also be high. In some instances, the beam manager 175 may determine the received signal quality based on subsequent channel state information.

[0071] In some instances, two or more beams may use different resource elements for providing communication services to respective mobile terminals. For example, the beam manager 175 may cause each beam to use different resource elements (e.g., a different combination of frequency channels, time slots, and polarizations) to provide communication to its respective mobile terminal while tracking the mobile terminal. By using different resource elements, interference between beams can be reduced or eliminated even when the mobile terminals may be close to each other.

[0072] In some instances, two or more beams can use the same resource element to provide communication services to corresponding mobile terminals. For example, the beam manager 175 can cause two or more beams to use the same combination of frequency channel, time slot, and polarization to provide communication to the corresponding mobile terminal while tracking the mobile terminal. This may be desirable when the mobile terminals are far enough apart so that the corresponding beams do not interfere with each other. By using the same resource element, more beams can be used with a particular set of resources, thereby increasing frequency reuse.

[0073] Figure 4 Another example of a satellite communication system 400 supporting mobile satellite beam conflict elimination according to an example disclosed herein is shown. The satellite communication system 400 may be an example of a satellite communication system discussed herein, such as the one described in reference to FIG. Figure 1 or Figure 3 Or the satellite communication system 100 or 300 described in aspects thereof.

[0074] The satellite communication system 400 may include a satellite network 101 having one or more satellites 105 configured to generate movable beamforming spot beams 150 (e.g., beams 150-a and 150-b) for communicating with a mobile terminal 120 (e.g., mobile terminals 120-a and 120-b) as the beamforming spot beams track the mobile terminal (e.g., mobile terminals 120-a and 120-b) (as controlled by a beam manager 175), as discussed herein.

[0075] In some instances, each beamforming spot beam 150 can be associated with a different mobile terminal 120. For example, the beam manager 175 can associate the beamforming spot beam 150-a with the mobile terminal 120-a and the beamforming spot beam 150-b with the mobile terminal 120-b. The beamforming spot beams 150 can have coverage areas 160 (e.g., coverage areas 160-a and 160-b). For clarity, the moving beamforming spot beam 150-a and the associated coverage area 160-a corresponding to the moving mobile terminal 120-a are shown in solid lines, and the moving beamforming spot beam 150-b and the corresponding coverage area 160-b corresponding to the moving mobile terminal 120-b are shown in dashed lines.

[0076] Figure 4 An example is shown of two mobile terminals 120-a and 120-b passing close to each other while traveling along respective paths 460-a and 460-b. As with beam 150-b and corresponding coverage area 160-b, path 460-b corresponding to mobile terminal 120-b is shown as a dashed line. Mobile terminals 120-a and 120-b may travel along paths 460-a and 460-b from respective starting locations, represented by A1 and A2, to respective end locations, represented by G1 and G2. Beams 150-a and 150-b are shown as being on an aircraft, although other mobile platforms may also be used. Beams 150-a and 150-b can track mobile terminals 120-a and 120-b, respectively, as the mobile terminals move along a path (e.g., by adjusting their respective coverage areas 160-a and 160-b by beam manager 175 in a manner coordinated with the movement of the mobile terminals) while providing communication services to the mobile terminals via the beams.

[0077] As mobile terminals 120 move closer to each other, interference between associated beams 150 may increase (e.g., when the beams use the same resource elements). As described herein, beam manager 175 can switch one or both beams to other resource elements to improve interference.

[0078] At points along paths 460-a and 460-b, represented by B1 and B2, the beams may begin to overlap each other, for example, by the mobile terminals moving toward each other. As used herein, beams may be considered to overlap based on the relative positions of the respective coverage areas of the beams. For example, beams 150-a and 150-b may overlap when the respective coverage areas of the beams 160-a and 160-b overlap each other. In some cases, the coverage areas of the beams may be centered on the locations of the mobile terminals that the beams are tracking. For example, coverage areas 160-a and 160-b may be centered on the locations of mobile terminals 120-a and 120-b, respectively. In some instances, the overlap of coverage areas may be based on the distance between the respective mobile terminals.

[0079] Further along paths 460-a and 460-b, mobile terminals 120-a and 120-b may reach another point, represented by C1 and C2, at which point one or more of the mobile terminals may enter the coverage area of ​​a beam that does not support the mobile terminal (e.g., does not provide communication service to the mobile terminal or does not track the mobile terminal) (e.g., due to the mobile terminals continuing to move toward each other). For example, at C1 / C2, mobile terminal 120-a may enter the coverage area 160-b of beam 150-b and / or mobile terminal 120-b may enter the coverage area 160-a of beam 150-a. At some point before or after this, the interference between beams 150-a and 150-b may increase to an unacceptable level. For example, the interference metric between the beams may meet (e.g., reach; or exceed; or reach or exceed) a threshold. As discussed herein, steps may be taken (e.g., by beam manager 175) to improve the interference (e.g., de-conflict the beams).

[0080] Mobile terminals 120-a and 120-b can each remain in the coverage area 160-a and 160-b of both beams 150-a and 150-b until another point along paths 460-a and 460-b, represented by E1 and E2. At this point, the mobile terminals can cease to be within the coverage area of ​​the other beam (e.g., by the mobile terminals moving away from each other). For example, at E1 / E2, mobile terminal 120-a can cease to be in the coverage area 160-b of beam 150-b, and mobile terminal 120-b can cease to be in the coverage area 160-a of beam 150-a. Even after the mobile terminals each cease to be within the coverage area of ​​the other terminal, the beams can still overlap. For example, at E1 / E2, the coverage areas 160-a and 160-b of beams 150-a and 150-b can still overlap.

[0081] Beams 150-a and 150-b may remain overlapping until another point along paths 460-a and 460-b, indicated by F1 and F2. At this point, beams 150-a and 150-b may cease to overlap (e.g., by the mobile terminals continuing to move away from each other). From this point along paths 460-a and 460-b to G1 / G2, beams 150-a and 150-b may remain separated and not overlap, as long as the mobile terminals remain sufficiently far apart from each other.

[0082] As about Figure 2A and 2B As discussed herein, beam manager 175 can use resource elements to provide communication services to mobile terminals via beamformed spot beams. In some instances, if two beams do not conflict (e.g., interference between the two beams is low), the beams can use the same resource element for providing communication services to the respective mobile terminals. For example, beam manager 175 can use the same resource element to provide communication services to mobile terminals 120-a and 120-b via beams 150-a and 150-b as long as the respective interference metrics between beams 150-a and 150-b remain below a threshold, as discussed herein.

[0083] As mobile terminals 120-a and 120-b move closer to each other (e.g., A1 / A2 to B1 / B2 and C1 / C2 to D1 / D2), interference between corresponding beams 150-a and 150-b may increase. This increase in interference may mean that communications via separate beams may be subject to excessive inter-beam interference (e.g., when using the same resource elements). When the interference increases to a certain level (e.g., an interference metric between beams meets a threshold), beam manager 175 may take steps to de-conflict the beams (e.g., improve the interference between beams).

[0084] In some instances, the interference metric may correspond to the measured interference of one or both of the beams. For example, the interference metric may correspond to the signal strength measured at the second terminal for the beam associated with the first terminal. Additionally or alternatively, the interference metric may correspond to a drop in the beam signal (e.g., a lower SNR), and the threshold may correspond to a specific level of the drop metric or a specific amount (e.g., a 3dB or 6dB SNR loss). In some instances, beam interference may be measured at a receiving device of the communication link. For example, beam interference may be measured at a mobile terminal (for a forward link) or a satellite (for a return link).

[0085] In some instances, the interference metric may correspond to channel correlation. For example, the interference metric may be based on the correlation between channel state information of two mobile terminals. The interference metric may be frequency dependent.

[0086] In some instances, the interference metric may correspond to an estimated interference for one or both of the beams. For example, the estimated interference may be based on the distance between the mobile terminals or based on an algorithm that estimates interference between the associated beams. In some instances, the interference metric may be based on the distance between the mobile terminals associated with the beams, and the threshold may correspond to a specific distance. For example, the threshold may correspond to the distance between the mobile terminals at which the coverage areas of the corresponding beams begin to overlap (e.g., at B1 / B2) or one of the mobile terminals enters the coverage area of ​​the beam corresponding to the other mobile terminal (e.g., at C1 / C2), or somewhere in between. Other distances are also possible.

[0087] In some instances, a single beam can be used to provide communication services to more than one mobile terminal. For example, the beam manager 175 can assign one of the terminals as a reference terminal for the beam to track while providing communication services. The reference terminal can have the task of providing channel state information to the beam manager 175 and can represent terminals in the same or similar locations. Other terminals can also communicate via beamforming spot beams, which are generated via beamforming coefficients with respect to the reference terminal. This can be achieved by sharing resources between mobile terminals. For example, via the same beam, communication services can be provided to two or more mobile terminals on the same frequency channel but in different time slots corresponding to the mobile terminals (e.g., by the beam manager 175). In some instances, the same frequency and time slot can be used for mobile terminals by further subdividing the time slots that can be addressed to different users (e.g., into MAC layer frames).

[0088] In some cases, unicast messages can be transmitted using two or more mobile terminals via the same beam. For example, a first unicast message can be transmitted to a first mobile terminal and a second unicast message can be transmitted to a second mobile terminal via the same shared beam. In some cases, unicast messages can be transmitted using a mobile terminal via the same beam. For example, a unicast message can be transmitted to a first and a second mobile terminal via the same shared beam. In some cases, unicast messages and multicast messages can be transmitted using a mobile terminal via different beams. In other cases, unicast messages and multicast messages can be transmitted using a mobile terminal via the same beam. For example, in a case where communication services are provided to more than one mobile terminal via a single beam (e.g., shared by the mobile terminals), unicast messages can be transmitted to each of the mobile terminals via the beam using different resources (e.g., different time slots), and multicast messages can be transmitted via shared resources (e.g., using shared time slots), or vice versa.

[0089] Figure 5An exemplary timing diagram 500 is shown for supporting mobile satellite beam conflict resolution according to examples as disclosed herein. The timing diagram 500 represents Figure 4 The beams 150-a and 150-b may provide communication services to the mobile terminals 120-a and 120-b using different resource elements when interference between the beams increases. Figure 3 and 4 As discussed, increased interference may occur, for example, when mobile terminals are in close proximity to each other while corresponding beams are using the same resource elements. As shown in timing diagram 500, one of the beams (e.g., beam 150-b) may be switched to a different resource element (e.g., by beam manager 175) to improve interference.

[0090] Both beams 150-a and 150-b may initially be allocated to the same resource element A at or before starting time t1 (e.g., by beam manager 175), which may correspond to mobile terminals 120-a and 120-b being at locations A1 / A2. Therefore, the satellite communication system may provide communication services to mobile terminals 120-a and 120-b via beams 150-a and 150-b at starting time t1 using the same resource element A.

[0091] The mobile terminals may be at a significant distance from each other at the starting time t1 such that beams 150-a and 150-b do not conflict with each other (e.g., even if the beams are assigned to the same resource element A, there may be little, if any, interference between the beams). Consequently, the interference metric between the beams may be relatively low (e.g., below a threshold). Beams 150-a and 150-b may be semi-statically assigned to the same resource element A (e.g., by beam manager 175) such that each terminal monitors and / or transmits on the same resource element until the terminal receives an instruction to switch its resource element.

[0092] At time t2, the interference between the beams may increase to an unacceptable level (e.g., the interference metric may meet a first threshold). In some instances, this may correspond to when one of the mobile terminals 120 enters the coverage area of ​​the other beam 150 (e.g., at or near C1 / C2). In some instances, this may correspond to when the mobile terminal 120 is located between B1 / B2 and C1 / C2. Other locations that meet the first threshold are also possible based on the interference metric value. Figure 4 Discuss some potential interference metrics and thresholds.

[0093] To improve interference, one of the beams may be changed to other resource elements (e.g., by beam manager 175). For example, at time t2, in response to the interference metric satisfying a first threshold, beam manager 175 may cause beam 150-b to switch resource elements (e.g., by reallocating beam 150-b to resource element B, which is different from resource element A) for providing communication services to mobile terminal 120-b. This may include changing one or more of the frequency, time slot, polarization, or other resources (e.g., one or more codes) associated with beam 150-b to resources different from those used by beam 150-a. In some instances, resource element B may be orthogonal to resource element A.

[0094] Because communication services can be provided to mobile terminals 120-a and 120-b via beams 150-a and 150-b using different resource elements after time t2, interference between beams 150-a and 150-b can be significantly reduced or no longer exist. Therefore, the satellite communication system can continue to provide communication services to mobile terminal 120-b without performing beam-to-beam switching.

[0095] At time t3, beams 150-a and 150-b may again use the same resource elements as each other. For example, at time t3, beam 150-b may revert back to the original resource elements (e.g., beam 150-b may be reallocated back to resource element A by beam manager 175) for providing communication services to mobile terminal 120-b. Alternatively, beams 150-a and 150-b may continue to use different resource elements. For example, beam manager 175 may cause beam 150-b to continue using resource element B after t3, rather than changing the resource elements of beam 150-b to resource element A.

[0096] Time t3 may correspond to when the interference or potential interference between the beams may no longer be at an unacceptable level (e.g., the interference metric may not reach or exceed the second threshold, or may be below the second threshold). The interference metric may or may not be the same interference metric used at time t2. Furthermore, if the interference metric is the same as the metric used at time t2, the second threshold may be the same as or different from the first threshold used at time t2. In some cases, t3 may correspond to when the mobile terminals are a certain distance away from each other. Figure 4 Discuss some potential interference metrics and thresholds.

[0097] After time t3, as long as the interference metric between the beams remains below a threshold (e.g., a first threshold or a second threshold), the satellite communication system can continue to provide communication services to the mobile terminal via beams 150-a and 150-b using the same resource element (e.g., resource element A) until at least time t4. Time t4 can correspond to mobile terminals 120-a and 120-b being at G1 / G2. However, if the interference between the beams increases to this level again (e.g., the interference metric again meets the first threshold), beam manager 175 can again switch one of the beams (e.g., beam 150-b) to a different resource element than the other beam, and in some instances, back again. This switching can be performed whenever the interference between the beams increases to this level. Thus, beam-to-beam switching can be avoided.

[0098] Figure 6 A block diagram 600 illustrates a beam manager 605 that supports mobile satellite beam conflict resolution according to examples as disclosed herein. The beam manager 605 may be Figure 1 The beam manager 605 may include a bus 625, a terminal tracker 620, a memory 630, a code 635, a processor 640, a beamformer 645, and a beam signal processor 650, and may be configured to control beam tracking and beam de-confliction of a mobile terminal via the antenna array 610.

[0099] The beam manager 605 may be located in a ground network of a satellite communication system (e.g., Figure 1 terrestrial network 135) or a satellite network (e.g., Figure 1 1). Alternatively, the beam manager 605 can be divided between the ground network and the satellite network. In one example (e.g., corresponding to a GBBF configuration), all components of the beam manager 605 can be located in the ground network. In another example (e.g., corresponding to an OBBF configuration), the beamformer 645 can be located in the satellite network (e.g., in one or more of the satellites), and the remaining components of the beam manager 605 can each be located in the ground network or the satellite network.

[0100] Antenna array 610 may be Figure 16. An example of an antenna for satellite network 101 of FIG. 6 is provided and may include antenna elements 615. In some examples, one or more of antenna elements 615 may be or include an antenna panel. The spacing between antenna elements 615 may be evenly distributed across the aperture of antenna array 610, or the spacing of antenna elements 615 may vary across antenna array 610. In some examples, a first antenna array 610 may be included in a ground segment, and a second antenna array 610 (e.g., one or more antenna arrays coupled to each other using a transponder) may be included in a space segment.

[0101] The bus 625 can represent an interface over which signals can be exchanged between components of the beam manager 605 and a location (e.g., a central location) that can be used to distribute signals to the signal processing components of the beam manager 605 (e.g., terminal tracker 620, beam signal processor 650, beamformer 645). The bus 625 can include one or more wired interfaces. Additionally or alternatively, the bus 625 can be a wireless interface for wirelessly communicating signaling between the signal processing components—e.g., according to a communication protocol. The beamformer 645 can be coupled to the antenna elements 615 via one or more wired or wireless interfaces.

[0102] Memory 630 may include volatile memory (e.g., random access memory (RAM)) and / or non-volatile memory (e.g., read-only memory (ROM)). Other types of memory are also possible. Memory 630 may store computer-readable and computer-executable code 635. The code may include instructions that, when executed by processor 640, cause beam manager 605 to perform the various functions described herein. Code 635 may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. In some cases, code 635 may not be directly executable by processor 640, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein. In some cases, memory 630 may contain, among other things, a basic I / O system (BIOS), which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0103] The processor 640 may include an intelligent hardware device (e.g., a general-purpose processor), a digital signal processor (DSP), a central processing unit (CPU), a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a programmable logic device (PLD), discrete gate or transistor logic components, discrete hardware components, or any combination thereof. The processor 640 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 630) to cause the beam manager 605 to perform various functions (e.g., functions or tasks that support mobile satellite beam conflict elimination). For example, the processor 640 and the memory 630 may be configured to perform the various functions described herein.

[0104] The beam signal processor 650 may be configured to process (e.g., demodulate, decode) a receive beam signal 654 received from the beamformer 645. The beam signal processor 650 may decode the data symbols included in the receive beam signal 654 to obtain a receive beam data signal 664. The information (e.g., data packets) in the receive beam data signal 664 may be transmitted (e.g., via one or more networks 125) to the destination device. The beam signal processor 650 may also be configured to process (e.g., encode, modulate) a transmit beam data signal 662 to obtain a transmit beam signal 652 for transmission to the beamformer 645. The transmit beam data signal 662 may include information (e.g., data packets) received (e.g., via one or more networks 125) for transmission to the terminal 120.

[0105] Terminal tracker 620 may be configured to use antenna elements 615 to determine which antenna elements to use with beamformer 645 to form beamformed spot beams (e.g., Figure 1 To determine information for forming the beamforming spot beams, the terminal tracker 620 may identify a group of terminals to be assigned as reference terminals (e.g., Figure 1 The terminal tracker 620 may determine a set of beamforming coefficients (e.g., phase shifts, amplitude components) that the beamformer 645 may use to generate a beamformed spot beam having a single coverage area for the spatial information associated with the reference terminal.

[0106] The terminal tracker 620 may determine beamforming coefficients to isolate signals transmitted on the beamforming spot beams from one another—for example, by emphasizing, in each beamforming spot beam, the signals transmitted within the beamforming spot beam and canceling interference from signals transmitted within other beamforming spot beams. The beamforming coefficients may be included in an M x N matrix, where the value of M may indicate the number of antennas and the value of N may indicate the number of spatial layers, where the value of N may be less than or equal to the value of M.

[0107] To transmit a beamformed spot beam via antenna element 615, terminal tracker 620 may target a frequency range or channel (e.g., Figure 2B frequency channel 210) and each of the one or more time periods (e.g., Figure 2B The beamformer 645 may apply the set of transmit beamforming coefficients to the set of transmit beam signals 652 associated with the beamforming spot beams to obtain component signals 656 for transmission via the antenna elements 615.

[0108] To receive the beamformed spot beam via antenna element 615, terminal tracker 620 may target a frequency range or channel (e.g., Figure 2B frequency channel 210) and each of the one or more time periods (e.g., Figure 2B A single set of receive beamforming coefficients is determined for time period 215, time slot t), which can be applied to component signals 656 by beamformer 645 to obtain a set of receive beam signals 654 associated with the beamforming spot beams.

[0109] In some examples, the beamforming coefficients may be determined at one or more satellites 105. In some examples, the beamforming coefficients may be received by one or more satellites from one or more ground stations (e.g., network device 130 or other sites of ground network 135) after terminal tracker 620 determines the beamforming coefficients.

[0110] In some examples, the terminal tracker 620, the beamformer 645, the beam signal processor 650, or various combinations or components thereof can be implemented in hardware (e.g., in a communication management circuit). The hardware can include a processor, a DSP, an ASIC, an FPGA or other PLD, discrete gate or transistor logic, discrete hardware components, or any combination thereof that is configured as or otherwise supports means for performing the functions described in this disclosure. In some examples, the processor and a memory coupled to the processor can be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0111] Additionally or alternatively, the terminal tracker 620, the beamformer 645, the beam signal processor 650, or various combinations or components thereof may be implemented in code 635 (e.g., as communication management software or firmware) executed by the processor 640. If implemented in code 635 executed by the processor 640, the functionality of the terminal tracker 620, the beamformer 645, the beam signal processor 650, or various combinations or components thereof may be performed by a general purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination of these or other programmable logic devices (e.g., units configured or otherwise supporting the functions described in the present disclosure).

[0112] Figure 7 A block diagram 700 is shown of a terminal tracker 720 supporting mobile satellite beam conflict cancellation according to examples as disclosed herein. The terminal tracker 720 may be as described in reference Figure 6 7. The terminal tracker 720 or its various components may be examples of apparatuses for performing various aspects of mobile satellite beam conflict elimination as described herein. For example, the terminal tracker 720 may include a communication manager 725, a resource element manager 730, a beamforming manager 735, a beam coefficient determiner 740, or any combination thereof. Each of these components may communicate with each other directly or indirectly (e.g., via one or more buses 715).

[0113] The communication manager 725 can be configured as or otherwise support means for providing communication services to a plurality of mobile terminals via a set of beamforming spot beams. In some instances, the communication manager 725 can be configured as or otherwise support means for providing communication services to a first mobile terminal and a second mobile terminal via a first beamforming spot beam and a second beamforming spot beam of a satellite communication system, as discussed herein. The first and second mobile terminals can be assigned to the first and second beamforming spot beams, respectively. In some instances, the communication manager 725 can include one or more of the other components of the terminal tracker 720. In some instances, the communication manager 725 can include a resource element manager 730, a beamforming manager 735, and a beam coefficient determiner 740.

[0114] As described herein, the resource element manager 730 can be configured to or otherwise support means for assigning the first and second beamforming spot beams to the same first resource element, as discussed herein. The resource element manager 730 can also be configured to or otherwise support means for reallocating the second beamforming spot beam to a second resource element different from the first resource element. The reallocation can be based on adjusting the respective coverage areas of the first and second beamforming spot beams and based on an interference metric between the first and second beamforming spot beams satisfying a threshold.

[0115] The beamforming manager 735 can be configured to or otherwise support means for applying beamforming coefficients to convert between beam signals associated with a set of beamforming spot beams and component signals associated with a plurality of antenna elements positioned on one or more satellites of the satellite communication system, as discussed herein. The beamforming manager 735 can also be configured to or otherwise support means for adjusting respective coverage areas of the first and second beamforming spot beams to track movement of the first and second mobile terminals within the coverage area of ​​the satellite communication system, as discussed herein.

[0116] In some examples, beam coefficient determiner 740 may be configured as or otherwise support means for determining beamforming coefficients prior to applying the beamforming coefficients to the component signals.

[0117] In some instances, aspects of one or more components of terminal tracker 620 or 720 may be found in other components of the terminal tracker or even external to the terminal tracker. For example, processor 640 and memory 630 may be used to execute one or more functions associated with components of terminal tracker 720.

[0118] Figure 8 A flowchart is shown illustrating a method 800 for supporting mobile satellite beam conflict resolution according to an example disclosed herein. The operations of the method 800 may be implemented by a satellite communication system or component thereof as described herein. For example, the operations of the method 800 may be implemented by a satellite communication system or component thereof as described herein. Figures 1 to 7 In some examples, a processor may execute a set of instructions to control functional elements of the beam manager to perform the described functions. Additionally or alternatively, the beam manager may use dedicated hardware to perform various aspects of the described functions.

[0119] At 805, the method may include providing communication services to a first mobile terminal and a second mobile terminal via a first beamforming spot beam and a second beamforming spot beam of a satellite communication system, wherein the first and second mobile terminals are assigned to the first and second beamforming spot beams, respectively. The operations of 805 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 805 may be performed by reference to Figure 7 In some examples, providing communication services may include the operations of 810, 815, and 820.

[0120] At 810, the method may include assigning the first and second beamforming spot beams to the same first resource element. The operations of 810 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 810 may be performed by reference to Figure 7 The resource element manager 730 described above is executed.

[0121] At 815, the method may include adjusting the coverage areas of the first and second beamforming spot beams to track the movement of the first and second mobile terminals within the coverage area of ​​the satellite communication system. The operations of 815 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 815 may be performed by reference to Figure 7 The beamforming manager 735 described above is performed.

[0122] At 820, the method may include reallocating the second beamforming spot beam to a second resource element different from the first resource element based on adjusting the respective coverage areas of the first and second beamforming spot beams and based on an interference metric between the first and second beamforming spot beams satisfying a threshold. The operations of 820 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 820 may be implemented as described in reference to Figure 7 The resource element manager 730 described above is executed.

[0123] In some examples, an apparatus as described herein may perform one or more methods, such as method 800. An apparatus may include features, circuits, logic, means, or instructions (e.g., a non-transitory computer-readable medium storing instructions executable by a processor), or any combination thereof, for performing one or more methods.

[0124] It should be noted that these methods describe examples of implementations, and that the operations and steps may be rearranged or otherwise modified to make other implementations possible. In some examples, aspects from two or more of the methods described may be combined. For example, aspects of each of the methods described may include steps or aspects of other methods, or other steps or techniques described herein.

[0125] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0126] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed as follows: a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0127] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored or transmitted as one or more instructions or codes on a computer-readable medium. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features implementing the functions may also be physically located at various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0128] Computer-readable media include both non-transitory computer storage media and communication media, including any medium that facilitates transferring a computer program from one place to another. Non-transitory storage media can be any available medium that can be accessed by a general or special-purpose computer. By way of example and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc read-only memory (CDROM) or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices or any other non-transitory media that can be used to carry or store the desired program code components in the form of instructions or data structures and can be accessed by a general or special-purpose computer or a general or special-purpose processor. In addition, any connection is correctly referred to as computer-readable media. For example, if a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwaves are used to transmit software from a website, server or other remote source, the coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwaves are included in the definition of media. As used herein, disk and disc include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0129] As used herein, including in the claims, "or" as used in a list of items (e.g., a list of items beginning with a phrase such as "at least one of" or "one or more of") indicates an inclusive list so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Likewise, as used herein, the phrase "based on" should not be understood to refer to a closed set of conditions. For example, an exemplary step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0130] In the drawings, similar components or features may have the same reference label. Additionally, various components of the same type may be distinguished by following the reference label with a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description applies to any of the similar components having the same first reference label, regardless of the second or subsequent reference labels.

[0131] The description set forth herein in conjunction with the accompanying drawings describes example configurations and does not represent all examples that may be implemented or within the scope of the claims. As used herein, the term "exemplary" means "serving as an example, instance, or illustration" and is not "preferred over" or "superior to" other examples. The detailed description includes specific details to provide an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some cases, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the examples being described.

[0132] The description herein is provided to enable one skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but rather is intended to reach the broadest possible agreement on the principles and novel features disclosed herein.

Claims

1. A method comprising: A first beamforming spot beam (150) and a second beamforming spot beam (150) via a satellite communication system (100) Providing a communication service to a first mobile terminal (120) and a second mobile terminal (120), wherein the first and second mobile terminals (120) are assigned to the first and second beamforming spot beams (150), respectively, wherein providing the communication service comprises: assigning the first and second beamforming spot beams (150) to the same first resource element; adjusting the respective coverage areas (160) of the first and second beamforming spot beams (150) to track movement of the first and second mobile terminals (120) within the coverage area (155) of the satellite communication system (100); and Based on adjusting the respective coverage areas (160) of the first and second beamforming spot beams (150) and Based on an interference metric between the first and second beamforming spot beams (150) satisfying a threshold, the second beamforming spot beam (150) is reallocated to a second resource element different from the first resource element.

2. The method of claim 1 , wherein the interference metric is based on one or more of: measuring interference between the first and second beamforming spot beams (150), an estimated interference between the first and second beamforming spot beams (150), correlation between the channels of the first and second mobile terminals (120), or The distance between the first and second mobile terminals (120).

3. The method according to claim 1 , wherein providing the communication service further comprises: After reallocating the second beamforming spot beam (150) to the second resource element and based on adjusting the respective coverage areas (160) of the first and second beamforming spot beams (150) and based on the interference metric between the first and second beamforming spot beams (150) satisfying a second threshold, reallocating the second beamforming spot beam (150) back to the first resource element. The method according to claim 3 , wherein the second threshold is equal to the threshold.

5. The method according to any one of claims 1 to 3, wherein providing the communication service further comprises: After reallocating the second beamforming spot beam (150) to the second resource element, the first beamforming spot beam (150) remains allocated to the first resource element.

6. The method of any one of claims 1 to 5, wherein the threshold is based on the respective beamwidths of the first and second beamforming spot beams (150).

7. The method according to any one of claims 1 to 6, wherein reallocating the second beamforming spot beam (150) to the second resource element comprises: The corresponding resource elements of the second beamforming spot beam (150) are changed to be orthogonal to the first resource elements.

8. The method according to claim 7, wherein changing the second resource element to be orthogonal to the first resource element comprises: At least one of a frequency of the second beamforming spot beam (150), a time slot assigned to the second beamforming spot beam (150), a polarization assigned to the second beamforming spot beam (150), or one or more codes assigned to the second beamforming spot beam (150) is altered.

9. The method of any one of claims 1 to 8, wherein adjusting the respective coverage areas (160) of the first and second beamforming spot beams (150) is based on measurements of signals transmitted with the first and second mobile terminals (120).

10. The method according to any one of claims 1 to 9, wherein providing the communication service further comprises: Beamforming coefficients are applied to component signals associated with a plurality of antenna elements (615) of the satellite communication system (100).

11. The method of claim 10, wherein providing the communication service further comprises: The beamforming coefficients are received from one or more ground stations (130) before being applied to the component signals.

12. The method of any one of claims 10 or 11, wherein adjusting the respective coverage areas (160) of the first and second beamforming spot beams (150) comprises: The beamforming coefficients are adjusted to move the respective coverage areas (160) of the first and second beamforming spot beams (150) to reflect the movement of the first and second mobile terminals (120).

13. The method of claim 12, wherein providing the communication service further comprises: The beamforming coefficients are received from one or more ground stations (130), wherein adjusting the beamforming coefficients includes applying the adjusted beamforming coefficients to the component signals.

14. The method according to any one of claims 1 to 13, wherein the first and second resource elements each comprise a frequency and a time slot.

15. The method according to any one of claims 1 to 14, wherein the first and second resource elements each comprise a polarization.

16. A system for satellite communications, the system comprising: one or more satellites (105); and A beam manager (175), the beam manager being configured to: providing a communication service to a first mobile terminal (120) and a second mobile terminal (120) via a first beamforming spot beam (150) and a second beamforming spot beam (150) of the one or more satellites (105), wherein the first and second mobile terminals (120) are assigned to the first and second beamforming spot beams (150), respectively, wherein to provide the communication service, the beam manager (175) is configured to: assigning the first and second beamforming spot beams (150) to the same first resource element; adjusting respective coverage areas (160) of the first and second beamforming spot beams (150) to track movement of the first and second mobile terminals (120) within a coverage area (155) of the satellite communication system (100); as well as Based on adjusting the respective coverage areas (160) of the first and second beamforming spot beams (150) and based on an interference metric between the first and second beamforming spot beams (150) satisfying a threshold, reallocating the second beamforming spot beam (150) to a second resource element (250) different from the first resource element (250).

17. The system of claim 16, wherein the interference metric comprises one or more of: measuring interference between the first and second beamforming spot beams (150), an estimated interference between the first and second beamforming spot beams (150), correlation between channels of the first and second beamforming spot beams (150), or The distance between the first and second mobile terminals (120).

18. The system according to any one of claims 16 or 17, further comprising: A ground station (130) is configured to communicate with the one or more satellites (105) via one or more satellite beams (132).

19. The system of claim 18, wherein the ground station (130) comprises a user terminal (UT) or a gateway.

20. The system according to any one of claims 16 to 19, wherein in order to provide the communication service, the beam manager (175) is further configured to: After reallocating the second beamforming spot beam (150) to the second resource element and based on adjusting the respective coverage areas (160) of the first and second beamforming spot beams (150) and based on the interference metric between the first and second beamforming spot beams (150) satisfying a second threshold, reallocating the second beamforming spot beam (150) back to the first resource element. The system of claim 20 , wherein the second threshold is equal to the threshold.

22. The system according to any one of claims 16 to 21, wherein in order to provide the communication service, the beam manager (175) is further configured to: After reallocating the second beamforming spot beam (150) to the second resource element, the first beamforming spot beam (150) remains allocated to the first resource element.

23. The system of any one of claims 16 to 23, wherein the threshold is based on respective beamwidths of the first and second beamforming spot beams (150).

24. The system according to any one of claims 16 to 23, wherein to reallocate the second beamforming spot beam (150) to the second resource element, the beam manager (175) is further configured to: The corresponding resource elements of the second beamforming spot beam (150) are changed to be orthogonal to the first resource elements.

25. The system of claim 24, wherein to change the second resource element to be orthogonal to the first resource element, the beam manager (175) is further configured to: At least one of the following is altered: a frequency of the second beamforming spot beam (150), a time slot assigned to the second beamforming spot beam (150), a polarization assigned to the second beamforming spot beam (150), or one or more codes assigned to the second beamforming spot beam (150).

26. The system of any one of claims 16 to 25, wherein adjusting the respective coverage areas (160) of the first and second beamforming spot beams (150) is based on measurements of signals transmitted with the first and second mobile terminals (120).

27. The system according to any one of claims 16 to 26, wherein in order to provide the communication service, the beam manager (175) is further configured to: Beamforming coefficients are applied to component signals associated with a plurality of antenna elements (615) of the one or more satellites (105).

28. The system of claim 27, wherein to provide the communication service, the beam manager (175) is further configured to: The beamforming coefficients are received from one or more ground stations (130) before being applied to the component signals.

29. The system of any one of claims 27 or 28, wherein to adjust the respective coverage areas (160) of the first and second beamforming spot beams (150), the beam manager (175) is further configured to: The beamforming coefficients are adjusted to move the respective coverage areas (160) of the first and second beamforming spot beams (150) to reflect the movement of the first and second mobile terminals (120).

30. The system according to claim 29, Wherein, in order to provide the communication service, the beam manager (175) is further configured to: receiving the beamforming coefficients from one or more ground stations (130), Wherein, in order to adjust the beamforming coefficients, the beam manager (175) is further configured to: The adjusted beamforming coefficients are applied to the component signals.

31. The system of any one of claims 16 to 30, wherein the first and second resource elements each comprise a frequency and a time slot.

32. The system of any one of claims 16 to 31, wherein the first and second resource elements each comprise a polarization.

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