Real-time multiplexing system and method from phased array antenna to modem

Abstract

To provide an antenna system for satellite communication that includes a platform upon which several phased antenna arrays are mounted and which can communicate with satellites, and is capable of being reconfigured in real time with a plurality of satellites.SOLUTION: An asset 200 capable of communicating with one or more satellites 1 to 4 can couple a plurality of computers 1 to n to a plurality of modems MD1 to MDn via a router 210, and can couple the plurality of modems MD1 to MDn to a plurality of antennas ESA1 to ESAn via a switch mechanism 205. The antennas ESA1 to ESAn are composed of phased array antennas and can be changed and controlled to any configuration by a control circuit 215.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD

[0001] (Related Application) The present disclosure claims the benefit of priority based on U.S. Provisional Application No. 62 / 874,447 filed on July 15, 2019, the entire disclosure of which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally to the field of wireless communications, for example, satellite-based communications and point-to-point microwave communications, as well as control of multiple phased array antennas in communication with a plurality of antennas.

BACKGROUND ART

[0003] (Related Art) Satellite-based communication is a common method for ships, airplanes, trains, and people to connect to the global Internet. Connection methods vary from simple connections at low frequencies to complex and expensive connections at high frequencies.

[0004] The complexity is primarily related to the antennas. Higher frequency communications require the use of antennas that are directed toward the satellite. While the user moves and the satellite is fixed relative to the Earth, the antenna may need to maintain its orientation toward the satellite. In some cases, the satellite moves, and the antenna must continuously maintain its pointing direction toward the satellite. In either case, autopilot antennas capable of maintaining directional steering offer significant advantages. The reverse is also true. In many cases, the satellite itself needs to direct its beam to a specific point on Earth. In any case, there is a transmitter and a receiver, and one or both of the two may need to steer the beam to establish their respective connections.

[0005] Autopilot antenna systems come in two forms: mechanically piloted antennas (MSAs), which utilize a motorized assembly to direct some form of parabolic dish, patch array, or other planar and three-dimensional antenna design toward a receiver, either directly or via some kind of amplifying lens; or electronically tuned directivity arrays (ESAs), which use various forms of electronically piloting the beam without moving parts, such as by phase shifting of a phased array antenna.

[0006] A common way to describe the performance of components like antenna systems is through SWAP-C+R, which represents size, weight, power consumption, cost, and reliability. These are some of the key factors that determine whether an antenna system is suitable for a particular purpose. As each of these variables increases, the number of applicable use cases for the antenna decreases. For example, trains require low-profile antennas to pass through tunnels, and airplanes also require low-profile antennas to minimize drag and reduce vortices that significantly affect flight characteristics. MSAs have the disadvantage of being physically tall and unreliable due to wear on moving parts over time. ESAs typically consume a lot of power and are heavy due to the heatsinks or other heat dissipation solutions associated with that power, and despite being physically smaller than MSAs, they are still very bulky and therefore ultimately expensive. However, ESAs are usually smaller and more reliable than MSAs, making them preferable for certain use cases.

[0007] Another important variable in antenna design is the aperture size. The aperture size represents the effective collection surface area of ​​the antenna. This is usually expressed as x and y coordinates in some form, and transmits This represents the surface area presented to the satellite. The most desirable antenna always faces the transmitter and has a large aperture (x and y) with no z (height / thickness). The larger the aperture size, the higher the gain of the received or transmitted signal, and therefore the better the overall spectral efficiency of the system, i.e., higher data rates can be obtained with less bandwidth, which would be a significant advantage in the market. Furthermore, the higher the gain, the less likely the transmitted beam is to direct power in an unintended direction and cause interference. This is because the beam becomes narrower as the gain increases. Moreover, the narrow beam of a high-gain antenna makes the antenna less susceptible to such unintended interference. From the standpoint of signal strength, a larger x / y surface area, i.e., aperture, is required, which also reduces the power amplifier level required for a given connection, i.e., the power that needs to be supplied to the antenna.

[0008] A challenge associated with the aforementioned technologies is that large SWAP-C+R limits the applications of antenna systems. The most efficient beam is a direct beam toward the front of the antenna itself, called the boresight. The boresight is a straight line perpendicular to the antenna's radiating plane, i.e., upward from the center of the antenna. MSAs can rotate the entire antenna, thus maintaining the boresight toward the satellite and thereby maintaining the aperture size presented to the satellite. Conversely, ESAs electronically tilt the beam, resulting in a smaller apparent aperture presented to the satellite, and therefore a 2-4 times decrease in performance depending on the off-angle axes of the receiver and transmitter. Also, the technical reduction in size results in a scanning loss of 10*log10COSΘ, which directly relates to the apparent area, i.e., the aperture size as seen from the direction of steering. MSAs have no scanning loss, but require a large sweep volume to maintain the direction of direction. This increases both size and weight. In some cases, antennas combine both ESAs and MSAs into a single antenna, using the ESA for one direction, perhaps the azimuth, and a mechanical steering assembly for the elevation direction. These exhibit a well-balanced SWaP-C+R for their respective applications.

[0009] Another problem with current antenna systems is that, due to physical size, the number of receiving and transmitting antenna assemblies is often limited to one per application. For example, an aircraft requires a controllable antenna to maintain a connection with a satellite. However, SWaP-C limits the number of controllable antennas to one. As a result, if the aircraft tilts and turns, the connection to the satellite is lost.

[0010] Furthermore, in many cases, the terminal needs to connect to multiple satellites simultaneously. Additionally, each satellite may require a special modem with a specific waveform, meaning that modem / antenna combinations may need to be switched as needed.

[0011] Therefore, technologies to improve satellite communications are needed. [Overview of the Initiative]

[0012] The following summary of this disclosure is intended to provide a basic understanding of some aspects and features of the present invention. This summary is not a broad overview of the present invention and is therefore not intended to specifically identify any major or important elements of the present invention or to delineate the scope of the present invention. Its sole purpose is to present some of the concepts of the present invention in a simplified form as a prelude to the more detailed description presented below.

[0013] The embodiments of this disclosure enable multiplexing of multiple antennas and modems, allowing for the configuration of different modem / antenna combinations and thereby generating transmission paths on the fly.

[0014] The disclosed embodiments can improve the control of communication paths between communication devices and satellites. In this embodiment, different communication paths are configured in real time based on parameters such as available satellites, the received signal strength from each of the available satellites, the amount and type of data to be transmitted, the transmission cost for each communication path, and the user's subscription and account permissions to use one of the available communication paths.

[0015] The disclosed embodiments enable real-time control of a mobile platform and inter-satellite communications, while maintaining the communication channel regardless of the movement of the platform, such as an airplane or a ship. The platform may have multiple phased array antennas, each with boresights pointing in a different direction relative to the platform (e.g., up, left, right). As the platform moves, for example, rotates, the controller can select and deselect antennas in real time, determining the best antenna to use for transmission and always selecting the antenna with the best RSSI (Received Signal Strength Indicator).

[0016] In the disclosed embodiments, a lower SWaP-C ESA configuration is employed by using variable dielectric technology in multiple ESAs, for example, in the phase shifters of the ESAs. The use of variable dielectric enables new connection methods for either satellite or ground antenna systems, and these new connection configurations are particularly advantageous for the embodiments disclosed herein.

[0017] While data encryption is often used for security purposes, encryption has limitations with the advent of quantum computing. Therefore, in the disclosed embodiment, multiple satellites are used to divide the data across at least one satellite and multiple other paths, and this data is reassembled in a secure location. Thus, even if individual paths are intercepted, only a portion of the encrypted data file will be represented. Therefore, the disclosed embodiment provides a more secure file transfer mechanism.

[0018] In other cases, it may be necessary to use multiple ESAs as follows: namely, when a platform such as a train or airplane moves and rotates, the ESA facing the largest boresight for maximum efficiency may be selected. Such a mechanism for automatically switching between ESAs is provided by embodiments disclosed herein.

[0019] In other cases, there may be rapid transitions and interference between multiple ESAs, i.e., it may be necessary to reduce the aperture size, and it may be necessary to make multiple ESAs usable and potentially position them at odd angles to each other, and the distance between such ESAs may be important. The disclosed embodiments also provide a method for utilizing very low SWaP-C ESAs and dynamically combining the signal strengths of these multiple ESAs, and potentially dynamically changing the modem associated with such various combinations of ESAs. Dynamic means managing in real time so that each of the various connections can be replaced or deleted at any moment, or new connections can be added favorably depending on the transmit / receive conditions.

[0020] Furthermore, in other cases where multiple ESAs exist, a baseband solution may include several MIMO-providing functions, either digital or analog, that provide zeroing or other baseband capabilities to improve the data rate.

[0021] In the disclosed embodiments, a satellite communications antenna system is provided, comprising a plurality of antennas, each including a phased array radiator; a plurality of modems; a switch that dynamically couples any of the aforementioned antennas to any of the aforementioned modems; a plurality of communication devices; a router that dynamically couples any of the aforementioned communication devices to any of the aforementioned modems; and a provision that provides real-time instructions for connecting the plurality of aforementioned antennas, the plurality of aforementioned modems, and the plurality of aforementioned communication devices. Includes a controller that controls switches and routers.

[0022] In a typical embodiment, the system includes a plurality of phased array antennas mounted on a mobile platform for satellite communications, each having a plurality of radiators and a plurality of phase shifters that introduce a delay to the RF signals propagating through them; at least one phase controller that operates the phase shifters to introduce the aforementioned delay to the aforementioned RF signals; a plurality of modems; switches that can operate to connect any aforementioned modulators / demodulators to any aforementioned phased array antennas in real time as determined; communication equipment; routers that can operate to route signals between any aforementioned modulators / demodulators and the aforementioned communication equipment; the aforementioned switches that form connections between the aforementioned modulators / demodulators and any aforementioned phased array antennas; and a control circuit that provides in real time instructions to the aforementioned routers for routing signals between the aforementioned modulators / demodulators and any aforementioned communication equipment.

[0023] In a typical embodiment, a method is provided for controlling communications between multiple phased array antennas and multiple satellites, receiving instructions from a computer device for data to be transmitted to the satellites, determining which satellites are available for communication, instructing the phased array antennas to orient themselves toward the selected satellites, receiving received signal strength (RSSI) signals from the phased array antennas, selecting a transmitting phased array antenna based on the RSSI signals, connecting the transmitting phased array antenna to a selected modulator, operating a router to connect the modulator to the computer device, and initiating the transmission of the data to be transmitted.

[0024] In a further aspect, a method for combining transmission signals received by a plurality of antennas is disclosed, which includes calculating the cross-correlation coefficients of the signals obtained from each of the aforementioned plurality of antennas, selecting the signal that generates the highest coefficient as the golden reference signal, using the golden reference signal to time-synchronize the aforementioned transmission signals received by the plurality of antennas, deriving a peak-to-average power ratio for each of the aforementioned transmission signals received by the plurality of antennas, generating respective weighting coefficients for the aforementioned transmission signals received by the plurality of antennas using the cross-correlation coefficients and the peak-to-average power ratios, applying the aforementioned weighting coefficients to each of the aforementioned transmission signals received by the plurality of antennas to generate a plurality of weighted signals, and summing the aforementioned plurality of weighted signals. This method may further include calibrating the phases of the transmission signals received by the plurality of antennas using the golden reference signal.

[0025] According to another aspect, a system provided for receiving transmission signals comprises a plurality of antennas each configured to receive a respective received signal, a ranking module configured to rank the aforementioned plurality of antennas according to the quality of each received signal, generate a corresponding level 1 signal, and select the highest-ranked antenna as the golden reference signal, a synchronizer configured to synchronize all received signals of the plurality of antennas using the golden reference signal, a level 2 module configured to calculate a peak-to-average power ratio for each respective received signal of the plurality of antennas and generate a corresponding level 2 signal, a scoring unit configured to generate a weighting score for each respective received signal of the plurality of antennas using the aforementioned level 1 signal and level 2 signal, a weighting module configured to apply the aforementioned weighting score to each corresponding received signal of the plurality of antennas to generate a plurality of weighted signals, and a summation module configured to combine all of the aforementioned weighted signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate examples of embodiments of the present invention, and together with the description thereof, serve to explain and illustrate the principles of the present invention. The drawings are intended to schematically show key features of the example embodiments. The drawings are not intended to illustrate all features of actual embodiments or to depict the relative dimensions of the illustrated elements and are not drawn to scale.

[0027] One or more embodiments of the present invention are illustrated by way of example, which are not limited to the accompanying drawings. It should be noted that in the accompanying drawings, like reference numerals refer to like elements. [Figure 1] Figure 1 shows an antenna array according to an embodiment, which has a controller that individually controls each of the phase shifters, thereby steering the direction of the main beam. [Figure 2] Figure 2 is an example of an embodiment deploying multiple phased array antennas for communicating with one or more satellites. [Figure 2A] Figure 2A is an example of an embodiment deploying multiple phased array antennas for communicating with one or more satellites. [Figure 3] Figure 3 shows an embodiment utilizing optical fibers for high-speed and efficient management of multiple signals. [Figure 3A] Figure 3A shows an embodiment utilizing optical fibers for high-speed and efficient management of multiple signals. [Figure 3B] Figure 3B shows an embodiment utilizing optical fibers for high-speed and efficient management of multiple signals. [Figure 4] Figure 4 is an example of an embodiment that generates path diversity that is particularly beneficial for secure file transmission or load balancing. [Figure 5] Figure 5 shows a flowchart of steps that can be used in the transmission processing of an embodiment. [Figure 5A] Figure 5A shows a flowchart of steps that can be used in the corresponding reception processing. [Figure 6]Figure 6 shows an architecture using multiple antennas for a receive diversity synthesis method according to an embodiment. [Figure 7] Figure 7 shows the channel structure in the receive diversity synthesis architecture according to this embodiment. [Figure 8] Figure 8 shows the digital signal processing architecture for reception diversity synthesis according to this embodiment. [Modes for carrying out the invention]

[0028] Embodiments of the real-time multiplexing antenna and control according to the present invention will be described with reference to the drawings. Different embodiments or combinations thereof may be used for different applications or to achieve different benefits. Depending on the results to be achieved, different features disclosed herein may be used in part or to the maximum extent, alone or in combination with other features, to balance the requirements and constraints and benefits. Therefore, while some benefits may be emphasized with reference to different embodiments, this does not limit the disclosed embodiments. That is, the features disclosed herein may not be limited to the embodiments describing them, but may be "mixed and adapted" with other features and incorporated into other embodiments.

[0029] References to satellites, platforms, or terminals in this specification are interchangeable and for illustrative purposes only. Physical locations may also be interchangeable so that the steerable beam and its effects can originate from a satellite, platform, terminal, or any other location. The same applies to receiving and transmitting. Either side may be the receiving or transmitting side, and the use of the terms receiving or transmitting is for illustrative purposes only and does not limit the reverse, or even simultaneous receiving and transmitting.

[0030] In many types of RF antennas, reception and transmission are symmetrical to each other, and a description of one is equivalent and applicable to the other. In this description, it may be simpler to describe the transmission, as the reception will be identical, differing only in direction. Furthermore, in the disclosed embodiments, the disclosed antenna is mounted on or integrated onto a platform, and its main beam is It is assumed that the antenna is pointed towards another antenna, which may be referred to as a target in this specification. The target antenna may also be mounted on a platform, and one or both platforms may be moving. For example, the antenna may be mounted on a vehicle such as an airplane, ship, or car, and its target may be attached to a satellite, for example. The concept of symmetry is also applicable here, where the antenna may be mounted on a satellite and its target may be mounted on a vehicle.

[0031] Figure 1 shows a phased array antenna, also referred to as an electronically tunable directivity or scanning array, which may be used in any embodiment disclosed herein. A phased array refers to an array of radiators that form a main beam, the direction of which can be electronically manipulated by changing the phase / time delay of the RF energy reaching each radiator. For simplicity, the figure shows a linear array, but in the disclosed embodiments, it is more beneficial to use a two-dimensional array so that the beam can be manipulated in two dimensions. The array includes radiating elements 105, each connected to a phase shifter 110. Each of the phase shifters 110 may be in the form of a delay line. The phase shifters 110 are controlled by a computer C, which introduces a certain amount of delay into the corresponding transmission line, thereby maneuvering the beam by an angle Θ from the boresight.

[0032] The signal generated by the transmitter TX is input to the shared feeder 115, where it is divided and distributed to each of the radiating elements 105. Before reaching the radiating elements, the signal from the feeder passes through the corresponding phase shifter 110, and the phase of the signal changes by an individual amount at each delay line, thus maneuvering the beam. The phase shifters 110 can also be controlled by an on-chip processor or a baseband processor. The range of each phase shifter can be quantized by a lookup table (LUT). The beam can be manipulated by quickly obtaining the phase value from memory. The reverse occurs during reception.

[0033] In the example of a passive phased array or passive electronically scanned array (PESA) shown in Figure 1, the antenna elements are connected to a single transmitter and / or receiver in a phased array. However, the disclosed embodiments are not limited to PESAs and rather encompass any electronically steerable antenna. For example, an active phased array or active electronically scanned array (AESA) can also be used. An AESA is a phased array in which each antenna element has an analog transmitter / receiver (T / R) module and performs the phase shift necessary to electronically steer the antenna beam. Alternatively, any disclosed embodiment may be implemented using a digital beamforming (DBF) phased array in which each element in the array has a digital receiver / exciter. Since the signals at each element are digitized by the receiver / exciter, the antenna beam can be digitally formed in a field-programmable gate array (FPGA) or array computer 110. In this method, multiple simultaneous antenna beams can be formed, for example, by grouping the radiating elements into subgroups.

[0034] Furthermore, the person in charge has developed a phased array antenna in which the phase shifter is formed using a delay line that crosses a variable dielectric constant material such as liquid crystal. Such a phased array antenna is also suitable for the embodiments disclosed herein. Examples of such arrays are described, for example, in U.S. Patent No. 7,884,766, U.S. Patent Application Publication No. 2017 / 0093363, U.S. Patent Application Publication No. 2018 / 0159213, and U.S. Patent Application Publication No. 2018 / 0062272, the contents of which are incorporated herein by reference in their entirety.

[0035] In general, for each of the disclosed embodiments, it should be understood that each antenna is an arbitrary electronically tunable directional antenna having multiple radiators, similar to the example of the phased array antenna shown in Figure 1. For simplicity, the term “phased array antenna” is used in the disclosure provided herein, which means that the direction is electronically tunable. It should be understood that this includes any electronically controllable antenna having multiple radiators that form a possible radiation pattern.

[0036] Figure 2 shows an embodiment in which multiple phased array antennas are deployed to communicate with one or more satellites. The configuration in Figure 2 allows for continuous real-time reconfiguration of the multiple phased array antennas. In Figure 2, asset 200 can be any platform having multiple communication devices, such as computers 1 to n, that communicate with one or more satellites 1 to 4. Asset 200 could be, for example, an airplane, a ship, a train, or a land-based facility.

[0037] The asset includes multiple antennas ESA1 to ESAn, which are coupled to multiple modems MD1 to MDn via a switching mechanism 205. Each antenna has a phased array whose beam shape and direction are controlled by a phase controller 220. The phase controller 220 sets the phase or time delay of the signal to each of the radiators in the phased array to form the desired main beam pointing in the desired direction. In this specification, the term phase controller is used as an abbreviation to refer to any controller used to electronically manipulate the beam formed by the radiators. For example, the phase controller 220 may control the time delay of the same-source RF signal when input to each of the radiators. In another example, the phase controller 220 may be a field-programmable gate array that digitally forms the antenna beam.

[0038] In some embodiments, the phase controller 220 can maintain a database, such as a lookup table, listing all available satellites in the sky and their positions. In some embodiments, the phase controller 220 can also receive GPS coordinates and other motion data of asset 200 from motion circuit 225 so that it can determine which satellites are within the field of view of its phased array. The phase controller 220 can use this information to steer each beam of the phased array in the appropriate direction toward the satellite.

[0039] In some embodiments, the phase controller 220 includes a control port that receives a control signal from the control circuit 215 indicating the satellite to which the antenna should communicate. The control circuit 215 may include a data port that functionally connects to the router 210, and as a result, the control circuit can actively make its switching decisions based on data collected from the router 210. The data may include the available bandwidth of each antenna, the data transmission rate of each antenna, and the type of transmission required by each communication device 1 to n (e.g., voice, video, data).

[0040] The control circuit can also be connected to each of the ESAs, and RSSI can be obtained from each of the ESAs. The control circuit can further be connected to the modem 255 to receive other data related to its switching decisions, such as the service level assigned to each communication device and the transmission cost of each satellite. For example, the modem 255 can be coupled to an external data management system 260, which can provide the control circuit 215 with data on various transmission parameters and user accounts.

[0041] The phase controller uses a database to calculate the phase delay to apply to each radiator so that the antenna is pointed towards the designated satellite. If asset 200 is a moving object, such as an airplane or ship, the motion circuit 225 continuously transmits motion signals to the phase controller 220, which in turn allows the phase controller to continuously adjust the phase applied to each radiator so that the beam remains pointed towards the satellite.

[0042] As mentioned above, the multiple communication devices are referred to here as computers 1 to n, and router 21 Modems MD1 to MDn are connected via 0. This configuration allows for real-time configuration of the system, enabling any communication devices 1 to n to be connected to any modems MD1 to MDn, and these to be connected to any antennas ESA1 to ESAn. This allows for efficient utilization of bandwidth from available satellites.

[0043] Multiple users on the platform may have diverse needs. For example, one computer might be for crew welfare, such as watching Netflix®, while another is for managing the ship's navigation. The control circuit 215 can determine which satellite to transmit each traffic and which antenna to use for that particular communication. The control circuit 215 can also instruct the router 210 to aggregate capacity for traffic or perform other Ethernet® level operations to ensure the best quality, best performance, and lowest cost across all available paths.

[0044] For example, in some embodiments, the control circuit 215 may receive data on the bandwidth capacity and utilization of various satellites, data on transmission priorities such as live signals like voice or video calls must have high priority while email may be assigned lower priority, and data on the bandwidth costs of various services available on the satellites. The control circuit 215 can then determine which satellite should be used for which transmission. In some embodiments, the control circuit also receives motion signals from the motion circuit 225, and as a result, the control circuit 215 can determine which satellite can be used for which antenna. In some embodiments, the control circuit 215 also stores the physical configuration of the asset 200 and its antennas in its database. For example, the asset may have ESA1 on its right, ESA2 on its left, ESA3 on the roof, etc. From this, the control circuit 215 can determine which part of the sky each antenna can scan. Using all this information, the control circuit 215 can provide appropriate signals to switches and routers, make appropriate connections, and indicate to each phase controller where to point the antennas.

[0045] For illustrative purposes, in Figure 2, both antennas ESA1 and ESA2 communicate with Sat1, which then communicates with transceiver 1. As a result, in one embodiment, the signal from Sat1 is too weak to transmit the required file over a single connection, and one possible solution is to use a receive diversity combining method with ESA1 and ESA2 to transmit the file over two connections. ESA3 communicates with Sat3, which then communicates with transceiver 2. ESAn communicates with both satellites Sat2 and Sat4. Sat2 communicates with transceiver 2, while Sat4 communicates with transceiver n. The two signals are routed by router 230 and combined by combining computer 235.

[0046] In one example shown in Figure 2, transceivers 1-3 are shown as part of a single base station 202 connected to a network 240, such as the Internet. The data storage device 245 can be accessed via the network 240 or permanently located at the base station itself. Of course, many base stations may be used, and the satellite can communicate with any selected base station depending on user needs, the performance of each base station, and available connections. Furthermore, because the data storage device 245 is accessible via the network 240, if a particular user machine needs to access the data storage device 245, the control circuit 215 can determine which satellite and base station are best suited to provide that connection. Therefore, in some embodiments, the control circuit 215 can periodically receive transmissions containing data on available base stations and their operating parameters. Similarly, in the case of non-geostationary satellites, the control circuit 215 can receive transmissions containing data on the satellite's position and operating parameters. It can periodically receive transmissions that include updates.

[0047] Each transceiver of the base station 202 has an antenna 204 for exchanging communication signals with one or more satellites. In the case of communication with geostationary satellites, the antenna 204 is a simple dish fixed in the direction of the satellite or mechanically moves to orient it towards the desired satellite. However, to quickly and in real time to maneuver, for example, non-geostationary satellites or high-speed movement between different satellites, one or more antennas 204 may be a phased array as disclosed herein.

[0048] In some disclosed embodiments, satellite transmission and reception can be performed via a one-way transmission mechanism. For example, the User Datagram Protocol (UDP) can be used for satellite transmission and reception.

[0049] Figure 3 shows an embodiment utilizing optical fibers for high-speed and efficient management of multiple signals. Each of the phased array antennas includes electro-optic transceivers EOT1 to EOTn that convert between optical and electrical signals. Optical signals travel through optical fibers, indicated by dashed arrows, managed by an optical fiber management unit (OFMU) 320. The OFMU 320 also includes electro-optic modulators that convert between optical and electrical signals. Signals traveling between the OFMU 320 and switch 205 are electrical signals and travel through waveguides and coaxial cables, indicated by solid arrows.

[0050] In the example shown in Figure 3, the OFMU 320 can connect any phased array antennas 1-n to any modems MD1-MDn via switch 205. The optical fiber management unit 320 can also sum the RF signals from multiple selected phased array antennas and provide the summed RF signal to the selected modems. Conversely, the optical fiber management unit 320 may distribute the transmit power to multiple selected antennas for transmission. Furthermore, the OFMU 320 can perform other digital baseband operations such as zeroing, beamforming, or interference cancellation.

[0051] Figure 3A shows a modified embodiment of Figure 3. The optical fiber management unit 320 also performs the functions previously performed by the switch 205. Since the optical fiber management unit 320 can combine and split signals, it can direct signals to any modulators MD1 to MDn, thereby eliminating the need for the switch 205. The control circuit 215 then transmits instruction signals to the OFMU 320 to perform appropriate signal routing.

[0052] Figure 4 illustrates an example of generating route diversity that is particularly beneficial for secure file transmission or load balancing. In the example shown in Figure 4, platform 400 can be any platform having one or more phased array antennas as described herein, and includes computer 411, which is attempting to transmit a file F. In one example, the file is highly sensitive, so it is desirable to thwart a man-in-the-middle attack, or, even if successful, ensure that the attacker can only obtain a portion of the data. In another example, the file is too large for the detected RSSI, so it may be desirable to use multiple routes, each of which transmits only a portion of the file.

[0053] As shown in Figure 4, computer 411 divides file F into several parts, in this case three. Next, control system 415 operates switches and routers (see Figure 1) to create three transmission paths, each directed to a different satellite. In the example shown in Figure 4, each satellite communicates with a different base station, so each part of the file is received by a different antenna and transceiver system. This is not always the case. Furthermore, some or all of the satellites may be communicating with the same base station. In any case, the control system 415, via the configurators CFG1 to CFGn, indicates to the base station which files to receive from which satellites, and when it receives some of the files, it indicates to the data center 422 that they should be assembled into a single file. The data center 422 may assemble and store them. Of course, any return response may be similarly divided and transmitted via multiple paths.

[0054] Note that in the example shown in Figure 4, the control system 415 resides in the cloud rather than on the platform 400. Such a configuration is not limited to this particular example and may be used in any embodiment disclosed herein.

[0055] Figure 5 is a flowchart showing the unordered steps that the process implemented by the disclosed embodiment may take. For example, in step 500, the registered user's account data is loaded into the control circuit 215. The account data may include data speed, data rate price, data limits, etc. The account data can be stored in the control circuit's memory. In step 505, satellite data can be loaded into the control circuit 215. The satellite data may include satellite ID, satellite coordinates, transmission speed, bandwidth, etc. In step 510, motion data can be uploaded to the control circuit 215. The motion data may include motion data related to the satellite and motion data related to the platform on which the ESA is mounted. Note that all data uploaded in steps 500, 505, and 510 may be updated periodically.

[0056] In step 515, a transmit request is received from the user. Using the transmit request information and the data uploaded in steps 500, 505, and 510, in step 520, an appropriate route for transmission is selected. For example, if multiple antennas are available, transmission may be performed by multiple routes using multiple antennas, for example, using a diversity combining method. In step 525, transmit / receive strength is verified for the antennas in the selected route. This is done, for example, by receiving RSSI from each unit. Once appropriate signal strength is confirmed for the selected route, the switches are configured so that the selected antennas connect to the selected modem, and the router is configured so that the user's machine connects to the selected modem.

[0057] Figure 6 shows an example of an embodiment that improves the overall signal-to-noise ratio (SNR) of a received signal by using multiple antennas, such as multiple phased arrays. Improving the SNR of a received signal using multiple antennas is known in the art, but current implementations are either inadequate or too complex and expensive for widespread implementation. For example, the simplest implementation is to determine which antenna provides the strongest total instantaneous signal (e.g., highest RSSI) and select the signal from that antenna. Another fast method is to apply equal weights to each antenna and sum the weighted signals from all antennas. While such a technique is quick and easy to implement, it may lose the signal quality of the best antenna and overweight weak signals, thereby introducing noise. For further details, readers should refer to "A Comparison of SNR Estimation Methods for AWGN Channels" by DRPaulluzzi and NCBeaulieu, IEEE Transactions on Wireless Communications, Vol. 48, No. 10, published October 2000. It is available at https: / / ieeexplore.ieee.org / document / 871393. The embodiment shown in Figure 6 provides an improved weighting method using a novel technique that is fast and relatively easy to implement.

[0058] The architecture shown in Figure 6 is called a Distributed Electron Variable Directional Array (DESA), and in the example in Figure 6, multiple arrays are used to synthesize diversity received signals, so D Instead of ESA, it may be called a receive diversity composite architecture. Such an architecture is particularly useful when the satellite is not visible to one or more arrays, or when the aperture is very small due to the beam tilt angle. This is illustrated in Figure 6 by considering a mobile platform 600, such as a ship, where the antennas are located in different parts of the ship. The ship moves in a direction such that the satellite is above starboard, and arrays x1, x2, and x3 (x3 is not shown as it is, for example, at the stern) have a good signal, but x4 is located on the port side and therefore cannot be steered towards the satellite, or the steer angle may result in a very small aperture and noise in the signal.

[0059] Modem 602 modulates signals for transmission from the internet, such as streaming video. These signals are uploaded from base station 604 to satellite SAT1, which broadcasts them toward Earth. Some or all of antennas x1-x4 pick up the signals, each potentially having a separate SNR due to various factors such as propagation loss, meteorological dynamics, polarization mismatch, interference, and the physical orientation of the array. The signals from the arrays are then processed by DESA processing unit 640 to generate digital signals to be provided to modem 648, which transmits the signals to various user devices. DESA processing unit 640 includes RF transceivers 642 that receive and digitize the signals from the antennas, and a digital signal processor 644 that determines the weights to apply to the signals from each antenna and sums up the weighted signals. DESA processing unit 640 also includes antenna array module AIM646, which is a controller responsible for maneuvering, geolocation, and system management of the phased array antennas. The AIM646 has a similar structure to the phase controller 220 described in Figure 2 and can provide similar operation and functionality.

[0060] Figure 7 shows an example of a received signal path embodiment that can be used in a received diversity synthesis architecture as shown in the example in Figure 6. In the example in Figure 7, there are as many channels as there are antennas, with only the first and last channels shown in detail, while the remaining channels are all identical and are therefore denoted by numerals. The disclosed method is frequency band independent and can be applied to any frequency band. Each antenna receives satellite signals and, as shown, transmits in the Ka or Ku band in this example. The signals pass through an RF filter and are then input to a standard low-noise block (LNB), which downconverts the signals to an intermediate frequency in the L band. After passing through an intermediate frequency filter, the signals are amplified and converted into digital signals by an RF ADC converter. The digital signal processor DSP644 then applies the calculated weights to each channel and sums the signals from all channels.

[0061] Figure 8 shows an example of a digital signal processor that may be used in a receive diversity synthesis architecture according to the embodiments disclosed herein. Due to path differences and other atmospheric effects, the signals of the channels need to be synchronized and calibrated to match each other. In the embodiment of Figure 8, this is first done by a channel scanner 850 that determines the channel with the highest fidelity by comparing the correlation of each channel with the remaining channels. Essentially, the channel scanner examines the channels and selects the most reliable channel as the golden reference channel. The golden reference channel is used by a time synchronizer 860 to estimate the time shift required to time align all channels. In one example, for each of the receive channels RxN, the time synchronizer 860 upsamples the signal to achieve the desired fractional sample accuracy. Next, the cross-correlation of the receive channels with the golden reference channel is determined. Then, the maximum coefficient value is set as the path delay difference and used to align the receive channels RxN with the golden reference channel.

[0062] Similarly, the golden reference channel is used by the phase calibration module 862 to estimate the phase shift required to align all channels. In one example, the received channel For each of RxN, the phase calibration module 862 calculates the average phase difference between the receiving channel RxN and the golden reference channel. Next, the average phase error value is applied to the receiving channel RxN.

[0063] As described above, the channel scanner 850 ranks the channels according to their relative fidelity or reliability. This is done first by the cross-correlation module 854 deriving a cross-correlation matrix. The ranking module 856 uses the results of the cross-correlation to generate a channel ranking order, which is referred to herein as Level 1 ranking, and selects a golden reference channel. The Level 1 signal is provided to the rank controller 870.

[0064] In this regard, the cross-correlation matrix is ​​derived as follows: JPEG0007933294000001.jpg21105 Here, m ≠ n, ns is the integral length, and nd is the delayed search window. For an N-channel receiver, the formula generates a cross-correlation coefficient of number d. JPEG0007933294000002.jpg21105d is an integer and relates to the triangular components of the following square matrix. JPEG0007933294000003.jpg48105 For example, if N=4, the formula generates an array of six coefficients. JPEG0007933294000004.jpg27105

[0065] The coefficients obtained from this matrix are used to determine the level 1 ranking. A Q matrix with dimensions N x (N-1) is defined, and the data for each channel is used exactly (N-1) times from the correlation matrix calculation. The correlation sum (CS) associated with each nth channel is calculated by adding all the row elements of Q and is given as follows: JPEG0007933294000005.jpg2075

[0066] For the example of N=4, the formula is as follows: JPEG0007933294000006.jpg29156

[0067] The golden criterion channel is selected based on the highest score as defined by the following pair: JPEG0007933294000007.jpg35130 Here, φ is a gain function including a normalized scaler. In the case of identical scores, one of the channels with the same score can be selected, or, in this embodiment, the result of a level 2 ranking decision can be used to select a golden reference channel with higher precision.

[0068] Referring back to Figure 8, the channel scanner 850 includes a peak-to-average power module 852, which calculates a level 2 ranking based on the peak-to-average power ratio (PAPR). This level 2 signal is input to the rank controller 870, which uses the level 1 and level 2 determinations to generate channel scores. These scores are provided to the weighting module 864, which applies the weights assigned to each channel, and the weighted signals of all channels are combined by the diversity combiner 866. Incidentally, as shown in the example in Figure 8, an optional external input port is provided to allow the user to disable the selection of the rank controller or provide other commands to the rank controller 870. The level 2 ranking determination is based on the calculation of PAPR using the following formula: JPEG0007933294000008.jpg3179 In this example, the peak power is less than 100% of the square of the maximum amplitude, for example, max{|x| 2}teeth This corresponds to 99% PAPR in the K-sample acquisition window. Using 99% PAPR helps avoid unrealistic peaks due to system errors, glitches, or sampling errors. A high PAPR indicates poor radio wave propagation channels and a low Eb / N0 (Energy per bit to noise power spectral density ratio, or normalized signal-to-noise ratio (SNR) measurement, also called "SNR per bit").

[0069] Ideally, the maximum CS value at Level 1 and the minimum PAPR value at Level 2 should correspond to the same receiving channel. The reference channel selection can be calculated using the following joint score. JPEG0007933294000009.jpg19132

[0070] Generally, scoring methods can use several decision variables based on multiple physical quantities. As shown above, in the example in Figure 8, the cross-correlation sum is used as the level 1 ranking and PAPR is used as the level 2 ranking. By using PAPR as another decision variable, the true channel SNR can be more accurately approximated, thus bringing us closer to the optimal synthesis solution. Furthermore, other variables such as total signal plus noise power (Psig) can also be used. Thus, a general description of determining the score of the nth channel of N multiple Rx channels can be expressed as follows: JPEG0007933294000010.jpg33126 Here SCORE= [SCORE1, SCORE2, ..., SCORE N ] is an N-dimensional array, Q is the total number of decision variables, φ is the gain function for normalization, and θ is a scalar function. Ideally, the maximum CS value at level 1 and the minimum PAPR value at level 2 should correspond to the same received channel. The reference channel selection can be calculated by a joint score to better approximate the true channel state. JPEG0007933294000011.jpg22126 Here, n is the channel number that gives the highest score.

[0071] For the example in Figure 8, where Q=2 (Level 1 ranking and Level 2 ranking) and N=4 channels, the formula for calculating the score is as follows: JPEG0007933294000012.jpg20142 This score is the value used as the weighting coefficient in the weighting module 864. Better conditions and higher quality channels are weighted exponentially more, resulting in a higher SNR at the output of the diversity synthesizer 866.

[0072] The provided disclosure discloses a method for synthesizing transmitted signals received by multiple antennas, the method comprising: calculating the cross-correlation coefficient of the signals obtained from each of the aforementioned multiple antennas; selecting the signal that produces the best coefficient as a golden reference signal; using the golden reference signal to time-synchronize the transmitted signals received by the multiple antennas; deriving a peak power-to-average power ratio for each of the transmitted signals received by the multiple antennas; using the aforementioned cross-correlation coefficient and peak power-to-average power ratio to generate weighting coefficients for each of the transmitted signals received by the multiple antennas; applying the weighting coefficients to each of the transmitted signals received by the multiple antennas to generate a plurality of weighted signals; and summing the aforementioned plurality of weighted signals. As described above, the method may further include calibrating the phase of the transmitted signals received by the multiple antennas using the golden reference signal.

[0073] A system for receiving transmitted signals is provided, and the aforementioned system comprises multiple antennas, each receiving a received signal, and multiple antennas according to the quality of the received signal from each of the multiple antennas. The system includes: a ranking module that ranks the antennas, generates corresponding Level 1 signals, and selects the highest-ranked antenna as the golden reference signal; a synchronizer that synchronizes all received signals from multiple antennas using the golden reference signal; a Level 2 module that calculates the peak-to-average power ratio for each of the received signals from multiple antennas and generates a corresponding Level 2 signal; a scoring unit that uses the aforementioned Level 1 and Level 2 signals to generate a weighted score for each of the received signals from multiple antennas; a weighting module that applies the aforementioned weighted scores to each of the corresponding received signals from multiple antennas to generate multiple weighted signals; and a summing module that combines all of the aforementioned weighted signals.

[0074] Figure 2A shows an example of an embodiment for satellite communications that achieves receive diversity synthesis to improve the overall SNR. The embodiment in Figure 2A is similar to the embodiment shown in Figure 2 and will therefore not be described in detail. The embodiment in Figure 2A shows how the DESA elements of Figures 7 and 8 can be incorporated into the architecture of Figure 2, thus enabling receive diversity synthesis and improving the overall SNR.

[0075] Similarly, Figure 3B shows an example of an embodiment for satellite communications, incorporating optical fiber and achieving receive diversity synthesis to improve the overall SNR. The embodiment in Figure 3B is similar to the embodiment shown in Figure 3 and will therefore not be described in detail. The embodiment in Figure 3B shows how the DESA elements of Figures 7 and 8 can be incorporated into the architecture of Figure 3, thus enabling receive diversity synthesis and improving the overall SNR.

[0076] Figure 5A shows a flowchart of an unordered procedure that can be taken to perform diversity receive synthesis to improve the overall SNR. In step 540, the signal is received by multiple antennas, which may include, for example, a cellular antenna, a Wi-Fi antenna, an array antenna, etc. Even if the data of the signals received by the antennas is the same, the quality of the signals received by each antenna may not be the same, so different SNRs or RSSIs may occur for each channel. This method proceeds to generate a weighted sum of the signals to improve the overall SNR, as follows. This method generates two ranked signals, a Level 1 ranked signal and a Level 2 ranked signal. The Level 1 ranked signal is generated in step 545 by obtaining the cross-correlation coefficients of the signals from multiple channels. The ranking is arranged so that the highest coefficient is the best signal and the lowest coefficient is the worst channel. Also in step 550, the best channel (highest coefficient) is selected as the golden reference signal. The Level 2 ranked signal is generated in step 555 by calculating the PAPR for each channel. The ranking is arranged so that the lowest PAPR corresponds to the best signal and the highest PAPR corresponds to the worst channel.

[0077] In step 560, the golden reference signal is used to synchronize the channels in the time domain. In step 565, the golden reference signal is used to calibrate the phase of all channels. In step 570, weights are generated using Level 1 and Level 2 ranking, and then the signal of each channel is weighted by the corresponding weight. In step 575, the weighted signals of the channels are added together.

[0078] It should be understood that the processes and techniques described herein are not inherently related to any particular apparatus and can be realized by any suitable combination of components. Furthermore, various types of general-purpose apparatus can be used in accordance with the teachings described herein. Although the present invention has been described in terms of specific examples, it is intended to be illustrative in all respects rather than limiting. Those skilled in the art will see that many different You will understand that the combination is suitable for carrying out the present invention.

[0079] Furthermore, other embodiments of the present invention will be apparent to those skilled in the art, considering the specification and practices of the present invention disclosed herein. Various aspects and / or components of the embodiments described herein can be used individually or in any combination. This specification and examples should be considered merely illustrative, and the true scope and spirit of the present invention are shown by the following claims.

Claims

1. A method for combining received signals from multiple antennas, A step of generating a ranking score for each antenna, For each of the two antennas m and n, the steps include calculating a cross-correlation coefficient based on a delay search window, the average signal strength of channel m over the integration length, and the instantaneous strength value of channel n at a predetermined time shift within the integration length. For each antenna n, the steps include: calculating the correlation sum CSn; and generating a ranking score. For each antenna, the step of generating a quality score that indicates the peak-to-average power ratio (PAPR) of the received signal, For each antenna, the steps include generating weights using the corresponding ranking score and quality score, For each antenna, the steps include applying the weighting to the received signal to generate a weighted signal, A method for synthesizing received signals from multiple antennas, comprising the steps of summing all weighted signals from the multiple antennas to generate a weighted composite signal.

2. The step of calculating the cross-correlation coefficient is to determine the coefficient for each of the two antennas m and n. The step includes calculating, Here, m ≠ n, ns is the integral length, and nd is the delayed search window. The average signal intensity of channel m over the integral length, The method according to claim 1, wherein is the instantaneous intensity value of channel n in the time shift τ within the integral length.

3. For each antenna n, the correlation sum CSn is The method according to claim 2, which is calculated based on the method described in claim 2.

4. The step of generating the ranking score is to give each antenna n a score The process further includes the step of calculating, The method according to claim 3, wherein φ is a gain function including a normalized scaler.

5. The method according to claim 1, further comprising the steps of assigning a received signal having the highest ranking score as a reference signal and aligning all received signals in time with the reference signal.

6. The method according to claim 1, further comprising the step of assigning a received signal having the highest ranking score as a reference signal and calibrating the phase of all received signals to the reference signal.

7. The steps include assigning the received signal with the highest ranking score and the lowest quality score as the reference signal, The steps of aligning all received signals in time with the reference signal, The method according to claim 1, further comprising the step of calibrating the phase of all received signals to the reference signal.

8. The method according to claim 1, wherein the step of generating the quality score includes the step of calculating PAPR using a numerator value that is less than 100% of the square of the maximum amplitude.

9. The method according to claim 1, wherein the step of generating the quality score includes the step of calculating PAPR using a numerator value which is 99% of the square of the maximum amplitude.

10. A method for combining received signals from multiple antennas, The steps include: calculating the cross-correlation coefficient of the received signals obtained from each of the aforementioned multiple antennas; The steps include selecting the signal that generates the highest coefficient as the golden reference signal, The steps include using the golden reference signal to synchronize the received signal in time, The steps include: deriving the peak-to-average power ratio (PAPR) of each received signal; A step of generating a weighting coefficient for each of the received signals using the cross-correlation coefficient and the peak-to-average power ratio, The steps include: applying the weighting coefficient to each of the received signals to generate a plurality of weighted signals; A method for synthesizing received signals from multiple antennas, comprising the step of summing up a plurality of weighted signals.

11. The method according to claim 10, further comprising the step of using the golden reference signal to calibrate the phase of the received signal.

12. The method according to claim 10, wherein the step of deriving the PAPR further includes the step of calculating a correlation sum CSn for each received signal.

13. The method according to claim 10, wherein the step of deriving the PAPR includes the step of using a numerator value that is less than 100% of the square of the maximum amplitude.

14. A system that combines received signals from multiple antennas, A signal digitizer that receives the aforementioned received signal and generates a digitized signal, A first ranking module ranks the digitized signals by comparing the correlation between each digitized signal and the remaining digitized signals, and selects the highest-ranked digitized signal as the reference signal. A second ranking module calculates the peak-to-average power ratio (PAPR) for each digitized signal, A weighting module that receives the ranking from the first ranking module, receives the PAPR from the second ranking module, and generates weights assigned to each digitized signal, A weighting applyer that generates a weighted signal by applying the weights assigned to each digitized signal, A system for synthesizing received signals from multiple antennas, including a summing module that sums the weighted signals.

15. The system according to claim 14, further comprising a time synchronizer for synchronizing the digitized signals according to the reference signal.

16. The system according to claim 14, further comprising a phase calibration module for calibrating the signal digitized according to the reference signal.

17. The system according to claim 14, wherein the first ranking module includes a cross-correlation calculation module.

18. The system according to claim 17, wherein the first ranking module further includes a correlation summing module that sums the cross-correlation coefficients calculated by the cross-correlation calculation module.

19. The system according to claim 14, wherein each of the antennas includes an electronically variable directivity array.

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