Antenna system for acquiring location information using polarization loss optimization

Abstract

The invention relates to an antenna system for acquiring location information using polarization loss optimization. Systems and methods for tuning a network device, such as an access point (AP), are provided. Examples herein receive, by an antenna of an AP, a circularly polarized signal and acquire a first linearly polarized component and a second linearly polarized component of the circularly polarized signal. The example also includes identifying a signal having a maximum signal power based on a comparison including the first linear polarization component and the second linear polarization component, acquiring geographic coordinates for the access point from the identified signal, and connecting to the network based on the acquired geographic coordinates.

Description

Background Art

[0001] Obtaining a reliable, accurate location of an access point (AP) or other network device is useful for many applications, such as the provision of network services and locating other devices on the network (such as client devices). Network device positioning technology includes measuring radio signals sent from various devices or entities, including satellites. For example, modern electronic devices include systems that can receive signals from satellite navigation systems, commonly referred to as global navigation satellite systems (each referred to as "GNSS"), and use the satellite signals to determine the location of the device. GNSS receivers can be integrated into network devices (such as APs, etc.). Signals from multiple satellites orbiting the earth can be received and processed by an integrated GNSS receiver to determine the location of the GNSS receiver, and the location of the network device is determined by the agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The present disclosure according to one or more various embodiments is described in detail with reference to the following drawings. The drawings are provided for illustration purposes only and merely depict typical or example embodiments.

[0003] Figure 1A and Figure 1B Illustrated are examples of network configurations that can be implemented according to the present disclosure.

[0004] Figure 2 Illustrated is the rotation of the electric field vector of an example circularly polarized electrical signal, which may be an example of a positioning signal according to the present disclosure.

[0005] Figure 3 is a schematic block diagram of an example receiver according to an implementation of the present disclosure.

[0006] Figure 4 Illustrated are example computing components that may be used to implement tuning network devices according to various implementations of the present disclosure.

[0007] Figure 5 is a schematic block diagram of another example receiver according to an implementation of the present disclosure.

[0008] Figure 6 is a flow chart of an example calibration process according to an example implementation.

[0009] Figure 7 is a schematic block diagram of another example receiver according to an implementation of the present disclosure.

[0010] Figure 8 is a flow chart of another example calibration process according to an example implementation.

[0011] Figure 9is a schematic block diagram of another example receiver according to an implementation of the present disclosure.

[0012] Figure 10 is a flow chart of another example calibration process according to an example implementation.

[0013] Figure 11 is an example computer system that can be used to implement the various features of the polarization loss optimization calibration of the present disclosure.

[0014] The drawings are not exhaustive and do not limit the disclosure to the precise forms disclosed. DETAILED DESCRIPTION

[0015] Implementations of the present disclosure generally relate to a GNSS receiver integrated into a network device that is capable of capturing multiple linear components of a circularly polarized signal for use in acquiring the location of the GNSS receiver. In various examples, the disclosed implementations can be integrated into a network device (such as an AP or other device connected to a network) that is placed in an indoor environment or other environment where line-of-sight propagation using a satellite is not possible (or unlikely). Line-of-sight (LoS) propagation refers to a property of electromagnetic radiation in which two devices send and / or receive signals when they are directly visible to each other and have no obstructions between them. As used herein, an "obstructed environment" refers to an environment in which LoS propagation is not possible due to obstructions (such as the structure of the indoor environment or any obstructions that may exist between two devices, whether indoors or outdoors).

[0016] The implementations disclosed herein can capture multiple linear components of a circularly polarized signal to determine the direction of rotation of the circularly polarized signal (sometimes referred to herein as "handedness"). The direction of rotation can be utilized by the disclosed implementations to identify the optimal signal for acquiring a location of a GNSS receiver.

[0017] As outlined above, GNSS (such as the United States' Global Positioning System (GPS)) can be used by network devices to obtain location information for themselves and / or other network devices. A GNSS receiver can detect GNSS signals encoded with location information and decode the detected GNSS signals to obtain the location information encoded therein. The location information can be provided as carrier frequency information, satellite identifiers, and navigation data (e.g., satellite orbit data, satellite clock information, satellite health information), which can be used to obtain the location or geographic coordinates of the GNSS receiver.

[0018] As mentioned above, a GNSS receiver can be integrated into a network device (such as an AP, etc.) to obtain location information of the network device and surrounding network devices connected to the network device. Each network device can have a built-in GNSS receiver to achieve location anchoring. In some cases, the network devices of the network can be deployed in an indoor environment, such as behind a wall, around a corner, on a ceiling, or other structure. This deployment may hinder LoS propagation or otherwise hinder LoS propagation between a GNSS receiver mounted on the network device and a GNSS satellite. In general, network devices that are close to windows or otherwise have unobstructed LoS with satellites can obtain more accurate location information relative to other network devices that lack LoS propagation with GNSS satellites. In this case, a network device that is closer to the window (referred to as an anchor network device) can detect GNSS signals and obtain its location information, which can be used to resolve the locations of other APs. For example, the anchor network device can perform fine timing measurement (FTM) measurements and synthesize the data to automatically locate other devices on the network (e.g., other APs and connected client devices). For example, each AP has a corresponding GNSS receiver that performs FTM measurements with neighboring APs to locate itself relative to the neighboring APs. Location can be synchronized with connected devices to locate these connected devices based on the FTM measurements.

[0019] In another example, a network device may use GNSS signals to obtain location information for providing network services to other connected devices (such as client devices). For example, a network device implemented as an AP may need to use GNSS to autonomously locate its geographic location and report this location in order to configure the frequency band usage of the AP. For example, the Federal Communications Commission (FCC) defines the Unlicensed National Information Infrastructure (U-NII) radio bands of radio spectrum that can be used by network devices. U-NII includes any of the following ranges: U-NII 1 to U-NII 4 for the 5 GHz band and U-NII 5 to U-NII 8 for the 6 GHz band. For U-NII 5 and U-NII 7, FCC guidelines may require automatic frequency coordination (AFC), which involves the AP performing autonomous positioning and reporting this location to the AFC database along with the FCC identification (FCCID), serial number, and other vendor-specific elements (VSE) associated with the AP. The AFC service can then reply to the AP with the provided frequency band and the power level allowed for the AP to avoid interference with incumbent devices on the network. The AP may then use the configured frequency band for providing services on the network.

[0020] GNSS signals transmitted by GNSS satellites generally employ right-hand circular polarization (RHCP) to transmit signals to Earth. Due to propagation losses as GNSS signals traverse the atmosphere to network devices on Earth, GNSS signals also tend to have relatively small amplitudes. Consequently, conventionally, GNSS receivers may need to be able to receive RHCP signals with sufficient passive gain, a low axial ratio between the orthogonal polarization components of the RHCP, and minimal polarization mismatch losses. Furthermore, GNSS receivers generally include a low-noise amplifier (LNA) that applies gain to the received GNSS signal to amplify it, which includes amplifying the noise floor imparted to the GNSS signal as it traverses the GNSS receiver. Thus, for a GNSS receiver, every decibel improvement in sensitivity can have a significant impact on accurately detecting GNSS signals and acquiring the location information encoded therein. Furthermore, enhancing the passive gain of the transmitted GNSS signal can have an improved effect on the sensitivity of the GNSS receiver, as the passive gain can amplify the GNSS signal transmitted by the satellite without increasing the noise floor at the GNSS receiver. That is, the component of the received GNSS signal encoded with the location information may be amplified without amplifying the noise component of the GNSS signal.

[0021] In addition, in obstructed environments, GNSS signals may be reflected by structures or other obstructions as they travel to the GNSS receiver. However, the polarization of the GNSS signal can change with each reflection, from RHCP to left-hand circular polarization (LHCP), or vice versa. The magnitude of the change in rotational direction can depend on the reflection angle or the angle of incidence, and as such, the reflected GNSS signal can exhibit any eccentricity between LHCP and RHCP. Therefore, if the GNSS signal is not reflected, or if the GNSS signal is reflected an even number of times, the GNSS receiver can receive a GNSS signal that is RHCP, or if the signal is reflected an odd number of times, the GNSS receiver can receive a GNSS signal that is LHCP. Therefore, for obstructed environments, receiving a direct RHCP GNSS signal is almost impossible, and the GNSS receiver may have to rely on reflected GNSS signals. For example, an indoor AP may have to rely on GNSS signals that pass through windows or similar open spaces, which are reflected one or more times before reaching the AP. In addition, each reflection attenuates the GNSS signal, thereby reducing the signal power after each reflection.

[0022] In some cases, the reflected GNSS signal may become elliptically polarized or have other polarization states. Therefore, the term "GNSS signal" as used herein refers to any RF signal that complies with GNSS technology and has a nonlinear polarization state that rotates in a left-handed or right-handed direction, including circular polarization, elliptically polarized, or non-polarized states. This allows a GNSS receiver to receive GNSS signals with varying polarization states transmitted from the same satellite in an obstructed environment.

[0023] To address the aforementioned technical issues, some GNSS receivers employ linearly polarized antennas coupled in series with an LNA. Examples of linearly polarized antennas include, but are not limited to, planar inverted-F antennas (PIFAs), wire antennas (e.g., dipoles, monopoles, etc.), loop antennas, antenna arrays, patch antennas, slot antennas, and aperture antennas (e.g., horns, waveguides, etc.). These linearly polarized antennas can receive the linearly polarized component of GNSS signals for location resolution. For example, a linearly polarized antenna can be configured to receive the vertically polarized component of a circularly polarized GNSS signal. Furthermore, a linearly polarized antenna can receive the linearly polarized component of a GNSS signal independently of the polarization rotation direction and can therefore receive both RHCP and LHCP signals. Therefore, a linearly polarized antenna can resolve unknown polarization states caused by reflections. However, a linearly polarized antenna may experience signal power loss due to polarization mismatch. For example, in the case of RHCP or LHCP GNSS signals, up to half of the signal power (e.g., up to a 3 dB loss) may be lost at the linearly polarized antenna before reaching the LNA. The amount of power loss may vary depending on the polarization state of the received GNSS signal (eg, circular polarization versus elliptical polarization).

[0024] Although RHCP antennas can receive RHCP GNSS signals more efficiently with almost no loss due to polarization mismatch, RHCP GNSS antennas may not be able to receive LHCP GNSS signals due to polarization mismatch. In addition, the signal power decreases with each reflection, so that after two reflections there may not be sufficient signal power to distinguish the location information encoded on the GNSS signal from the noise floor. Therefore, RHCP antennas cannot fully solve the technical problems discussed above in obstructed environments. For example, an RHCP antenna may only depend on the direction it is pointing relative to the satellite. Therefore, an RHCP antenna may be most effective when pointing towards the sky toward the satellite. However, in many indoor environments, the antenna is mounted on the ceiling, in which case the antenna can be directed in a downward direction toward the ground. Therefore, the ceiling-mounted antenna may rely on lateral GNSS signals or reflected GNSS signals, and the RHCP antenna may lose efficiency in these configurations.

[0025] Thus, implementations disclosed herein provide a network device comprising a receiver (such as a GNSS receiver) configured to capture multiple linearly polarized components of a received circularly polarized signal. Thus, the disclosed implementations provide for receiving a GNSS signal with increased signal power relative to a single linearly polarized component. In various examples, the network device may be an AP configured to obtain location information of an AP from a received GNSS signal according to the examples disclosed herein. In an example, the AP may be configured to connect to a network based on the obtained location information. In other examples, the AP may be configured to determine the location of other network devices on the network based on the received GNSS signal.

[0026] In various examples, a receiver includes a dual-polarized antenna configured to capture two linearly polarized components of a GNSS signal. For example, the dual-polarized antenna can acquire a first linearly polarized component and a second linearly polarized component of a circularly polarized signal. The linearly polarized components can be polarized orthogonally relative to each other (e.g., a vertical component and a horizontal component). Thus, the disclosed implementations can capture two linearly polarized components of a GNSS signal independently of the polarization rotation direction.

[0027] The network device of the present disclosure may include a controller (e.g., a processor or other computing component). The controller may be configured to identify a signal having a maximum signal power based on a comparison of a first linear polarization component and a second linear polarization component. The controller may be configured to calibrate a receiver based on the identified signal. The receiver may be configured to demodulate the identified signal to obtain location information encoded thereon (e.g., carrier frequency information, satellite identifiers, and navigation data—such as satellite orbit data, satellite clock information, satellite health information, which can be used to obtain location or geographic coordinates).

[0028] The controller can utilize various methods for identifying a signal based on a comparison of a first linearly polarized component and a second linearly polarized component. For example, the controller can be configured to compare the amplitude of the first linearly polarized component with the amplitude of the second linearly polarized component to determine which linearly polarized signal has the greatest signal power. The controller can then calibrate the receiver to use the identified linearly polarized signal, which can be used to obtain geographic coordinates. For example, the controller can calibrate the receiver to enhance signals received from a particular satellite. The receiver can then be operated to simultaneously receive signals from multiple satellites and stitch together signals received at different points in time to obtain geographic coordinates.

[0029] In another example, the controller can identify a signal based on applying phase delays to linearly polarized components. For example, the controller can be configured to iteratively apply multiple phase delays to a first linearly polarized component. For each phase delay, the phase-delayed first linearly polarized component can be combined with a second linearly polarized component to generate a combined signal. The controller can then determine the signal power of each combined signal and identify the combined signal with the maximum signal power. The controller can then calibrate the receiver to use the identified combined signal.

[0030] In yet another example, the controller can identify a signal based on combining linearly polarized components to create a combined circularly polarized signal. For example, a first linearly polarized component and a second linearly polarized component can be input to first and second inputs of a switch (e.g., a diamond switch as known in the art). The outputs from the switches can be combined to provide a first combined circularly polarized signal. The inputs can then be flipped to output a second combined circularly polarized signal. The signal power of the first combined circularly polarized signal can be compared to the signal power of the second combined circularly polarized signal to identify which is greater. The controller can then calibrate the receiver to use the combined circularly polarized signal with the maximum signal power.

[0031] It should be noted that the terms "optimize," "optimal," and the like, as used herein, may be used to refer to achieving or realizing as efficient or perfect a performance as possible. However, as will be appreciated by those of ordinary skill in the art reading this document, perfection cannot always be achieved. Thus, these terms may also encompass achieving or realizing as good or efficient or practical a performance as possible under given circumstances, or achieving or realizing a performance that is better than that achievable using other settings or parameters.

[0032] Before describing examples of the disclosed systems and methods in detail, it is useful to describe an example network installation (also referred to as a deployment) with which the disclosed systems and methods can be implemented in various applications. Figure 1A and Figure 1B 1 illustrates an example of a network configuration 100 that can be implemented for an organization, such as a business, an educational institution, a government entity, a healthcare facility, or other organization. The organization of the network configuration 100 can include multiple users (or at least multiple client devices 110) and possibly multiple physical or geographic sites, such as a main site 102, a remote site 132, and a remote site 142. The network configuration 100 can include the main site 102 in communication with a network 120. The network configuration 100 can also include one or more remote sites 132, 142 in communication with the network 120. The network 120 can allow each geographic site of the organization's network configuration 100 to communicate with each other.

[0033] The primary site 102 may include a primary network, which may be, for example, an office network, a home network, or other network installation. The network of the primary site 102 may be a private network, such as a network that may include security and access controls to limit access to authorized users of the private network. Authorized users may include, for example, employees of a company at the primary site 102, residents of a residence, customers of a business, and the like.

[0034] In the illustrated example, the primary site 102 includes a network controller 104 that communicates with a network 120. The network controller 104 can provide communication with the network 120 for the primary site 102, although the network controller 104 may not be the only point of communication between the primary site 102 and the network 120. Although the primary site 102 may include multiple controllers and / or multiple points of communication with the network 120, a single network controller 104 is illustrated. In some examples, the network controller 104 communicates with the network 120 through a router (not shown). In other examples, the network controller 104 provides router functionality to devices in the primary site 102, such as the client devices 110.

[0035] The network controller 104 may be operable to configure and manage network devices (such as at the primary site 102), and may also manage network devices at the remote sites 132 and 142, such as a gateway device 134, an access point (AP) 136, a switch 138, a gateway device 144, and an AP 146. The network controller 104 may be operable to configure and / or manage switches, routers, access points, and / or client devices connected to the network. The network controller 104 may itself be an AP or may provide the functionality of an AP.

[0036] The network controller 104 can communicate with one or more switches 108 and / or wireless APs 106A-106C. The switches 108 and wireless APs 106A-106C can provide network connectivity to various client devices 110A-110J. Using connections to the switches 108 or APs 106A-106C, client devices 110A-110J can access network resources, including other devices on the network of the primary site 102 and other devices on the network 120.

[0037] Examples of client devices may include desktop computers, laptop computers, servers, web servers, authentication servers, authentication-authorization-accounting (AAA) servers, domain name system (DNS) servers, dynamic host configuration protocol (DHCP) servers, Internet protocol (IP) servers, virtual private network (VPN) servers, network policy servers, mainframe computers, tablet computers, e-readers, netbook computers, televisions and similar monitors (e.g., smart TVs), content receivers, set-top boxes, personal digital assistants (PDAs), mobile phones, smart phones, smart terminals, dumb terminals, virtual terminals, video game consoles, virtual assistants, Internet of Things (IoT) devices, etc. The client vendor may use client devices (such as client devices 110A-client devices 110J, client devices 140A-client devices 140D, and / or client devices 150A-client devices 150B) to connect to the network of the primary site 102, the network of the remote site 132, and / or the network organization of the remote site 142.

[0038] Within the primary site 102, a switch 108 is included as an example of a point of access to a network established at the primary site 102 for wired client devices 110I-110J. Client devices 110I and 110J can connect to the switch 108 and, through the switch 108, can be able to access other devices within the network configuration 100. Client devices 110I and 110J can also access a network 120 through the switch 108. Client devices 110I and 110J can communicate with the switch 108 via a wired connection 112. In the illustrated example, the switch 108 communicates with the network controller 104 via the wired connection 112, although the connection can also be wireless.

[0039] Wireless APs 106A-106C are included as another example of a point of access to a network established at master site 102 for client devices 110A-110H. Each of APs 106A-106C may be a combination of hardware, software, and / or firmware configured to provide wireless network connectivity to wireless client devices 110A-110H. In the illustrated example, APs 106A-106C may be managed and configured by network controller 104. APs 106A-106C may communicate with network controller 104 and the network of master site 102 via connection 112, which may be a wired interface or a wireless interface.

[0040] Network configuration 100 may include one or more remote sites, such as remote site 132. Remote site 132 may be located at a different physical or geographic location than primary site 102. In some cases, remote site 132 may be located at the same geographic location as primary site 102, or perhaps in the same building, but lack a direct connection to the network of primary site 102. Instead, remote site 132 may connect to the network of primary site 102 using a connection on a different network (e.g., network 120). Remote site 132 may be, for example, a satellite office, another floor or suite in a building, etc. Remote site 132 may include a gateway device 134 for communicating with network 120. Gateway device 134 may be a router, a digital-to-analog modem, a cable modem, a digital subscriber line (DSL) modem, or some other network device configured to communicate with network 120. Remote site 132 may also include a switch 138 and / or an access point 136 that communicate with gateway device 134 via a wired or wireless connection. Switch 138 and AP 136 may provide connectivity to the network for various client devices 140A-140D.

[0041] In various examples, the remote site 132 can communicate directly with the primary site 102, such that client devices 140A-140D at the remote site 132 access network resources at the primary site 102 as if the client devices 140A-140D were located at the primary site 102. In such examples, the remote site 132 can be managed by the network controller 104 at the primary site 102, and the network controller 104 can provide the necessary connectivity, security, and accessibility to enable the remote site 132 to communicate with the primary site 102. Once connected to the primary site 102, the remote site 132 can function as part of the private network provided by the primary site 102.

[0042] In various examples, the network configuration 100 may include one or more smaller remote sites (such as remote site 142) that include only a gateway device 144 for communicating with the network 120 and a wireless access point 146 through which various client devices 150A-150B can access the network 120. Such a remote site 142 may represent, for example, the residence of a single employee or a temporary remote office. The remote site 142 may also communicate with the main site 102, allowing client devices 150A-150B at the remote site 142 to access network resources at the main site 102 as if the client devices 150A-150B were located at the main site 102. The remote site 142 may be managed by the network controller 104 at the main site 102 to enable this transparency. Once connected to the main site 102, the remote site 142 may function as part of the private network provided by the main site 102.

[0043] The network 120 may be a public or private network (such as the Internet), or other communication network that allows connectivity between the various sites 102, 132, and 142, as well as access to servers (such as servers 160A-160B). Servers 160A-160B may also be devices and / or nodes for remote computing that may be executed to perform the functions disclosed herein. Thus, the implementations disclosed herein may be run directly on APs 106A-106C, on servers 160A and / or 160B, or distributed across APs and servers in a post-processing manner. The network 120 may include third-party telecommunication lines, such as telephone lines, broadcast coaxial cables, fiber optic cables, satellite communications, cellular communications, and the like. The network 120 may include any number of intermediate network devices, such as switches, routers, gateways, servers, and / or controllers, that are not directly part of the network configuration 100 but that facilitate communication between various parts of the network configuration 100 and between the network configuration 100 and other network-connected entities. The network 120 may include various content servers (such as servers 160A-160B). Servers 160A-160B may include various providers of multimedia downloadable and / or streaming content, which may include audio, video, graphics, and / or text content, or any combination thereof. Examples of servers 160A-160B may include, for example, web servers, streaming radio and video providers, and cable and satellite television providers. Client devices 110A-110J, client devices 140A-140D, and client devices 150A-150B may request and access multimedia content provided by servers 160A-160B via the network 120.

[0044] Despite Figure 1A While the example of FIG. 1 illustrates ten client devices 110A-110J at primary site 102, in various applications, a network may include a smaller or larger number of client devices. In fact, some implementations may include a significantly larger number of client devices. For example, various wireless networks may include hundreds, thousands, or even tens of thousands of clients that can potentially communicate simultaneously with their respective APs.

[0045] The network configuration 100 may include a configuration to provide Figure 1A The location information of the network device is shown in the positioning system 170. For example, Figure 1A As shown in the example of , AP 106A includes a receiver 118 that can receive a positioning signal from positioning system 170, which can be used by receiver 118 to resolve the location of receiver 118 and, by extension, the location of AP 106A. Figure 1A A single receiver is depicted in , but can similarly be used in Figure 1A Other receivers may be provided in other network devices, such as other APs 106B-106C, switch 108, and the like. Location information may be provided as the latitude and longitude, and possibly altitude, of a receiver (e.g., receiver 118). Location information may also be provided as a relative location of the receiver, such as expressed as a distance north or south, east or west, and possibly above or below some other known fixed location. Location may also be specified as a geodetic location (such as latitude and longitude), a municipal location (e.g., in terms of a street address or using other location-related names and labels), a local location (e.g., in terms of distance from a known structure or object in an environment (e.g., a building having an indoor environment including walls, ceilings, etc.)).

[0046] Positioning system 170 may include one or more satellites, such as satellites 172A-172C (collectively referred to as satellites 172 or individually as satellites 172). Each satellite 172A-172C may transmit a corresponding positioning signal 174A-174C to a network device. Position signals 174A-174C may include location information 176A-176C, respectively. A receiver, such as receiver 118, may detect positioning signals 174A-174C, obtain the location information 176A-176C encoded thereon, and estimate the location of the receiver based on the received location information 176A-176C. For example, receiver 118 may receive positioning signals 174A-174C and demodulate each positioning signal 174A-174C to obtain location information 176A-176C. Location information 174A-174C may include, but is not limited to, information that can be used to resolve the geographic coordinates of receiver 118. For example, each signal 174A-174C may include carrier frequency information, satellite identifiers, and navigation data (e.g., satellite orbit data, satellite clock information, satellite health information), which can be used to obtain the location or geographic coordinates of receiver 118. Based on the location information, receiver 118 can resolve (e.g., estimate) its current geographic location. For example, location information 174A-174C obtained from multiple satellites 172 can be used to resolve the geographic coordinates of receiver 118.

[0047] exist Figure 1AIn the example shown, three satellites are depicted for illustrative purposes. However, positioning system 170 may include any number of satellites 172. Positioning system 170 may include, for example, a constellation of satellites 172 in geostationary orbit, to simultaneously transmit electromagnetic signals (e.g., positioning signals 174A-174C) from multiple satellites in the constellation to locations across a large portion of the Earth's surface. Satellites that are members of a particular positioning system may transmit positioning signals in a format unique to that particular positioning system. A receiver (e.g., receiver 118) may be used to determine the absolute location and relative location of a network device in which the receiver is installed. For example, satellite 172 may broadcast positioning signals 174A-174C that may be received by receiver 118. Receiver 118 may determine the absolute position of AP 106A by processing positioning signals 174A-174C. Satellites 172A-172C may orbit at an altitude, for example, from approximately 20,000 km to approximately 23,000 km, and may have known time and ephemeris. Satellites 172A-172C may broadcast positioning signals 174A-174C that include a pseudo-random pattern. Positioning signals 174A-174C may include a carrier frequency in the L-band, such as 1575.42 MHz (L1), 1227.6 MHz (L2), or 1176.45 MHz (L5) modulated at approximately 1 MHz and / or approximately 10 MHz. Because the satellites are always in motion, receiver 118 may continuously acquire and track positioning signals 174A-174C from satellites 172. Receiver 118 may demodulate received positioning signals 174A-174C to obtain location information 174A-174C and calculate the distance from receiver 118 to the set of satellites based on the speed of electromagnetic waves (e.g., the speed of light) and the propagation time of the incoming signal through space (e.g., time of flight), which may be determined using satellite and receiver local clocks.

[0048] In various examples, positioning system 170 may be a GNSS, and satellite 172 may be a GNSS satellite. GNSS satellites may be, for example, but not limited to, satellites used in the Global Positioning System (GPS, United States), Galileo (European Union), GLONASS (Russia), BeiDou (China), etc. In these examples, satellite 172 may broadcast positioning signals 174A-174C as GNSS signals, which generally have RHCP polarization. Receiver 118 and may be Figure 1AOther receivers deployed in network devices may be GNSS receivers. For example, receiver 118, implemented as a GNSS receiver, may receive broadcast GNSS signals from satellites 172A-172C, respectively. Based on the GNSS signals, receiver 118 may determine the absolute location of AP 106A by demodulating received signals 174A-174C to obtain location information 176A-176C.

[0049] Although the examples described herein refer to AP 106 obtaining location information from positioning system 170, the present disclosure is not intended to be limited to only that implementation. AP 106 is provided as an illustrative example, and other network devices may be implemented to receive positioning signals from satellites of positioning system 170. For example, switch 108, switch 138, AP 136, gateway device 144, etc. may each include a receiver (such as receiver 118) for receiving the positioning signals and estimating the location of the corresponding network device.

[0050] The network devices may be configured to utilize the acquired location information when providing the services and functions of the respective network devices. As an example, APs 106A-106C may detect positioning signals and acquire their respective location information, which may be used to resolve the locations of other APs or network devices on network 120. In the illustrative example, receiver 118 of AP 106A may receive and detect positioning signals 174A-174C and estimate its location based on location information 176A-176C contained therein. AP 106A may be considered an anchor AP that may use its location to resolve the locations of other network devices (such as, but not limited to, other APs, switches, client devices, etc.) on network 120. AP 106A may perform fine timing measurement (FTM) measurements and synthesize data based on the FTM measurements to locate other network devices and estimate the locations of the other network devices.

[0051] As another example, network devices (such as APs 106A-106C) may use their respective location information to provide network services to connected network devices (such as client devices 110A-110J). For example, APs 106A-106C may need to perform autonomous positioning by estimating their geographic location and report the configuration of the frequency bands used by APs 106A-106C. The FCC defines the U-NII radio bands of radio spectrum that may be used by network devices (such as APs 106A-106C). U-NII includes any of the following ranges: U-NII 1 to U-NII 4 for the 5 GHz band, and U-NII 5-U-NII 8 for the 6 GHz band. For U-NII 5 and U-NII 7, FCC guidelines may require AFC. Under AFC, APs 106A-106C may be required to determine their geographic location and autonomously report that location to the AFC database along with the FCC ID, serial number, and other VSEs associated with the respective APs. The AFC service may then reply to the APs 106A-106C using the configured frequency bands and power levels allowed for each AP 106A-106C to avoid interfering with incumbent devices on the network. The APs 106A-106C may then use the configured frequency bands to provide network services to other network devices.

[0052] As mentioned above, positioning signals, such as GNSS signals, typically propagate with circular polarization. Figure 2 The figure illustrates the rotation of the electric field vector of an example circularly polarized electrical signal 200, which can be an example of a positioning signal (e.g., positioning signals 174A-174C). In this example, the circularly polarized electrical signal 200 propagates in the +Z direction. The circularly polarized electrical signal 200 can include a first component 202 having an electric field that oscillates in a first plane (e.g., a vertical plane, shown as the YZ plane in this example) and a second component 204 having an electric field that oscillates in a second plane orthogonal to the first plane (e.g., the XZ plane in this example). Therefore, both the first component 202 and the second component 204 can be linearly polarized and synchronized with each other. Depending on the phase and / or amplitude difference between the first component 202 and the second component 204, the combined electrical wave can be linearly polarized, circularly polarized, or elliptically polarized. For example, when the phase of the first component 202 and the phase of the second component 204 are the same, the combined electrical wave can be a linearly polarized wave with the electric field vector pointing in the same direction. As another example, where the amplitudes are different, the combined wave may be elliptically polarized.

[0053] In a circularly polarized signal, the electric fields of the two orthogonal vector components 202 and 204 may not peak simultaneously, but may instead peak 90° (e.g., 1 / 4 wavelength) apart relative to each other. Instead, the resulting combined vector of the two components 202 and 204 may rotate 360° per wavelength during propagation, as shown by the circularly polarized electrical signal 200. The direction of circular rotation, or handedness (e.g., right-handed or left-handed), may be determined by whether the first component 202 or the second component 204 peaks first. For example, if the second component 204 peaks first, followed by the first component 202, the electromagnetic wave may be RHCP. However, if the first component 202 peaks first relative to the second component 204, the electromagnetic wave may be LHCP.

[0054] Circularly polarized signals can be more tolerant of physical orientation mismatches between a transmitting antenna (e.g., at a satellite) and a receiving antenna at a receiver. For example, if a satellite transmits a signal with vertical polarization, a vertically oriented linear antenna can receive a strong signal, but if the receiving antenna is oriented at an angle relative to vertical, the received signal strength may be reduced (e.g., if the antenna is oriented horizontally, the received signal strength may be reduced by more than 20 dB). However, if a satellite transmits a circularly polarized signal, a receiver with a linear antenna can receive the signal regardless of whether the linear antenna is oriented vertically or horizontally, but only the component of the circularly polarized signal is aligned with the linear orientation of the receiving antenna.

[0055] In obstructed environments, reflections may be unavoidable as the signal bounces off surfaces. Some receivers may not have LoS with the satellite and therefore only receive the reflected signal. The direction of the circular rotation can be altered by reflections, causing RHCP electromagnetic waves to flip to LHCP when reflected by the structure of an object. In other cases, the direction of the circular rotation can be altered by reflections, causing the direction of the rotation received by the receiver to be reversed.

[0056] For example, referring back to FIG. 1 , network devices may be deployed in an obstructed environment, the boundary of which is illustratively shown as site 102. As illustrative examples, site 102 may be an indoor environment, such as an office, a facility, or any physical structure (e.g., a building) having an opening 116 (e.g., a window or doorway) to the outside environment. In this example, AP 106A may be positioned near opening 116, which provides a Figure 1A172. However, AP 106B, AP 106C, and switch 108 may be deployed elsewhere in an obstructed environment some distance from port 116, resulting in obstructed LoS propagation. For example, AP 106B may be deployed on a wall around a corner, such that another wall is between AP 106B and satellite 172. In another example, AP 106B and / or AP 106C may be deployed on a ceiling, with antennas directed downward toward the ground (e.g., Figure 1B shown).

[0057] Installed in Figure 1A Obstruction of LoS propagation between a receiver on a network device and a satellite (such as satellite 172) can negatively impact the receiver's ability to receive positioning signals (e.g., positioning signals 174A-174C) and obtain the location information encoded therein. Positioning signals (such as those transmitted by satellite 172) generally employ RHCP, and in obstructed environments, positioning signals may be reflected before reaching the receiver, causing a switch from RHCP to LHCP, or vice versa. Consequently, receiving direct RHCP positioning signals in such environments may be nearly impossible.

[0058] For example, Figure 1B As shown, AP 106C and AP 106B may have to rely on the positioning signal passing through opening 116, which may be reflected one or more times before reaching the corresponding AP. Figure 1BIn the illustrative example of FIG, AP 106B is deployed on ceiling 105 of room 107 at master site 102, and AP 106C is deployed on ceiling 101 of room 109. The antennas of AP 106B and AP 106C can be directed toward the ground. In this case, for example, AP 106B can receive positioning signal 174D as a direct LoS transliteral, where positioning signal 174D has a nearly linear polarization. Alternatively, or in combination with positioning signal 174D, AP 106B can receive positioning signal 174E, which enters through opening 116 and is reflected by the ground before being received by AP 106B. AP 106C can similarly receive reflected positioning signal 174G. This reflected signal can be a skewed LHCP. As another example, positioning signal 174F can be scattered when incident on the ground. The scattered signal can be linearly polarized. AP 106B may also receive direct vertical reception that is RHCP, such as positioning signal 174H; however, the signal will be attenuated due to passing through ceiling 105. Therefore, receiving a direct RHCP positioning signal with sufficient signal power in this environment to obtain the location information encoded therein is nearly impossible.

[0059] Although circularly polarized antennas can be implemented in APs 106A-106B to effectively receive circularly polarized electronic signals, the antennas may need to be oriented according to the rotational direction of the circular polarization. Otherwise, the antennas may not be able to receive the transmitted positioning signal due to polarization orientation mismatch. In addition, the signal strength / power (e.g., amplitude) may decrease with each reflection, so that after two reflections, the signal may not have sufficient signal power for the receiver to distinguish between the information encoded on the signal and the noise floor.

[0060] Thus, linearly polarized antennas, such as, but not limited to, patch antennas, inverted-F antennas (IFAs), PIFAs, wire antennas, loop antennas, antenna arrays, patch antennas, slot antennas, aperture antennas, and the like, may be implemented in a receiver for detecting circularly polarized electromagnetic signals at the network device of FIG. 1 . As mentioned above, linearly polarized antennas may receive RHCP signals, LHCP signals, elliptically polarized signals, and / or linearly polarized signals. This is particularly true in obstructed environments (e.g., as described above). Figure 1A(As described in the example of site 102 of FIG. 1 ), a linearly polarized antenna can be used to receive RHCP signals via LoS propagation, as well as LHCP signals caused by reflections. However, a linearly polarized antenna with a single polarization can only detect one component of the circularly polarized signal (e.g., one of the first component 202 or the second component 204, depending on the orientation of the linearly polarized antenna). As a result, there can be a loss of up to 3 dB in the signal level received by the linearly polarized antenna (e.g., half the power of the circularly polarized signal).

[0061] Thus, examples of the present disclosure provide a receiver including an antenna configured to capture (e.g., detect) multiple linearly polarized components of a received circularly polarized electromagnetic signal. For example, the receiver 118 may include an antenna capable of detecting multiple linearly polarized components of the positioning signal 174. Such an antenna may be referred to herein as a multi-polarized antenna. In some examples, the multi-polarized antenna may be implemented as a dual-polarized antenna configured to capture two linear components (e.g., a vertical component and a horizontal component) of a circularly polarized electromagnetic signal.

[0062] As an example, refer to Figure 1B , AP 106B and AP 106C may include receivers (e.g., receiver 118) capable of detecting multiple linearly polarized components. In the case of positioning signal 174E (e.g., panned reception), components of linearly polarized positioning signal 174E may be aligned (e.g., matched) with one or more of the polarizations of the antenna of AP 106C. A similar situation may occur for scattered positioning signal 174F. In the case of reflected positioning signal 174D and reflected positioning signal 174G being skewed LHCPs, the LHCPs are eccentric relative to the linear components of the antenna, such that one or more components of reflected positioning signal 174D and reflected positioning signal 174G may be captured.

[0063] Figure 3 is a schematic block diagram of an example receiver 300 according to an implementation of the present disclosure. The receiver 300 may be included in (eg, installed, embedded in, or otherwise attached to) a network device such as, Figure 1A 106A-AP 106C or other network devices) and is configured to receive location signals (such as 174A-174C). In an example implementation, receiver 300 may be a GNSS receiver capable of receiving GNSS signals and extracting location information from the incoming signals. As described above, the GNSS receiver may be configured to estimate the geographic location of the GNSS receiver based on the location information extracted from the GNSS signals, and the location information may be extended to the network device in which the GNSS receiver is embedded.

[0064] Receiver 300 may include an antenna 310, a radio frequency (RF) front end 320, and a processing engine 330. RF front end 320 and processing engine 330 may each include various modules that may be implemented in hardware, software, or a combination thereof.

[0065] Antenna 310 may be configured to receive circularly polarized signals, such as those generated by Figure 1A Circularly polarized signals transmitted by satellite 172. Antenna 310 can be configured to receive signals in different frequency bands, polarizations, and elevation angles. Antenna 310 can be implemented as a multi-polarized antenna configured to receive circularly polarized signals (e.g., RHCP signals and / or LHCP signals) and capture multiple linearly polarized components of the circularly polarized signals. For example, antenna 310 can be a dual-polarized antenna configured to capture a first component and a second component of the circularly polarized signal. For example, antenna 310 can include a first linear component 318 oriented in a first direction and a second linear component 316 oriented in a second direction. The first linear component 318 can be oriented to detect the first component of the circularly polarized signal, while the second linear component 316 can be oriented to detect the second component of the circularly polarized signal. As an illustrative example, the first component can be a vertical component, and the second component can be a horizontal component. Therefore, in this example, the first linear component 318 can be the vertically oriented component of antenna 310, and the second linear component 316 can be the horizontally oriented component of antenna 310. In some examples, antenna 310 may be implemented as a dual-polarized cross-dipole antenna, a two-pin patch antenna, or other dual-polarized antenna known in the art.

[0066] The antenna 310 may be electrically connected to the RF front end 320 via a plurality of component paths, each component path corresponding to a captured linearly polarized component of a circularly polarized signal. Figure 3 In the example of FIG, the receiver 300 includes a first component path 312 and a second component path 314, and the first component and the second component of the signal captured by the antenna 310 can be sent to the RF front end 320 through the first component path 312 and the second component path 314, respectively. In the case of more than two components, additional component paths can be included.

[0067] The RF front end 320 may include a pre-filter section 322 and a pre-amplifier section 324. The pre-filter section 322 may include a plurality of filters 323 and a filter 325, which may be configured to filter the signal received from the antenna 310 to remove signals outside the carrier frequency band (e.g., L-band) associated with the antenna 310, reduce the effects of aliasing, and limit the noise bandwidth. For example, the filter 323 may be connected to the first component path 312 and receive a first component of a circularly polarized signal. The filter 323 may be configured to filter the first component to remove signals outside the carrier frequency band of the antenna 310, reduce the effects of aliasing, and limit the noise bandwidth. The filter 325 may be connected to the second component path 314 and receive a second component of the circularly polarized signal. The filter 325 may be configured to filter the second component to remove signals outside the carrier frequency band of the antenna 310, reduce the effects of aliasing, and limit the noise bandwidth.

[0068] The pre-amplifier section 324 may generally include a plurality of low-noise amplifiers (LNAs) 327 and 329, which are configured to amplify the signal filtered by the pre-filter section 322 to increase the signal strength (also referred to as signal power) to a level suitable for downstream processing. For example, the LNA 327 may receive the filtered first component from the filter 323 and amplify the signal to a suitable level for processing. Similarly, the LNA 329 may receive the filtered second component from the filter 325 and amplify the signal to a suitable level for processing.

[0069] The appropriate level for processing may refer to the signal power level received from the satellite within the receiver's sensitivity level to accurately decode the signal. The higher the signal level for the received signal, the more accurately the location can be determined by the receiver. As an illustrative example, the minimum received signal at the antenna may be approximately -128.5 dBm for the L1 signal and approximately -127 dBm for the L5 signal. After filtering and amplification, example nominal values for carrier-to-noise levels may be approximately 40-45 dB for L1 and 42-47 dB for L5.

[0070] The processing engine 330 may include, for example, a controller 332 configured to execute a calibration module 334 and / or a position determination module 336. The controller 332 may be, for example, a processor or other computing system (e.g., Figure 11The controller 332 may perform a calibration process at the calibration module 334 based on the first component and the second component of the circularly polarized signal output from the front end 320. For example, based on a comparison of the first component and the second component, the controller 332 executes the calibration module 334 to identify the signal with the maximum signal power. Figure 4 、 Figure 6 ,and Figure 8 , provides additional details on an example calibration process performed by calibration module 334.

[0071] The controller 332 may also execute a location determination module 336 to determine the location of the receiver 300 based on the circularly polarized signal received by the antenna 310. For example, the location determination module 336 may execute a process to determine the location of the receiver 300 based on the signal identified during the calibration process. For example, the location determination module 336 may be executed to obtain location information from the identified signal, which the receiver 300 may use to estimate the current location of the receiver 300. In an example, the controller 332 may execute a demodulator 338 to demodulate the identified signal, and the location information contained on the signal may be decoded by the location determination module 336. The location determination module 336 may then use the decoded location information to estimate the location of the receiver 300, as described above.

[0072] Therefore, because antenna 310 is able to capture multiple linear components, receiver 300 is able to resolve the position of receiver 300 regardless of the rotational direction of the circularly polarized signal. Therefore, regardless of the rotational direction of the circularly polarized signal, antenna 310 can capture the various components of the incoming signal and process them separately to identify the optimal signal for use in determining position.

[0073] Figure 4 Illustrated are example computing components that may be used to implement tuning (eg, calibration) of network devices according to various implementations of the present disclosure. Referring now to Figure 4 , the computing component 400 may be, for example, a controller (e.g., Figure 1A The network controller 104 and / or Figure 3 332), or any other similar computing component capable of processing data. The computing component 400 can be included as part of a network device such as the network device described in conjunction with FIG. 1 (e.g., an AP or otherwise). Figure 4 In an example implementation of , computing component 400 includes a hardware processor 402 and a machine-readable storage medium 404. In some examples, computing component 400 may not necessarily include machine-readable storage medium 404 and may be communicatively coupled (e.g., via a wired connection or a wireless connection) to machine-readable storage medium 404.

[0074] The hardware processor 402 may be one or more central processing units (CPUs), semiconductor-based microprocessors, and / or other hardware devices suitable for retrieving and executing instructions stored in the machine-readable storage medium 404. The hardware processor 402 may retrieve, decode, and execute instructions (such as instructions 406-412) to control a process or operation for tuning a network device. Alternatively, or in addition to retrieving instructions and executing instructions, the hardware processor 402 may include one or more electronic circuits including electronic components for performing the functions of one or more instructions, such as a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or other electronic circuits.

[0075] A machine-readable storage medium, such as machine-readable storage medium 404, can be any electronic storage device, magnetic storage device, optical storage device, or other physical storage device that contains or stores executable instructions. Thus, machine-readable storage medium 404 can be, for example, random access memory (RAM), non-volatile RAM (NVRAM), electrically erasable programmable read-only memory (EEPROM), a storage device, an optical disk, or the like. In some examples, machine-readable storage medium 404 can be a non-transitory storage medium, where the term "non-transitory" does not encompass transient propagating signals. As described in detail below, machine-readable storage medium 404 can be encoded with executable instructions (e.g., instructions 406-412).

[0076] The hardware processor 402 may execute instructions 406 to receive a circularly polarized signal by an antenna. In various examples, a network device may include a receiver, such as, Figure 3 Receiver 300. In this way, the antenna may be implemented as antenna 310. The circularly polarized signal may be a GNSS signal, which is a RHCP GNSS signal.

[0077] The hardware processor 402 may execute instructions 408 to obtain a first linearly polarized component of a circularly polarized signal and a second linearly polarized component of the circularly polarized signal. The first linearly polarized component may be orthogonal to the second linearly polarized component. For example, the first linearly polarized component may be a vertically polarized component and the second linearly polarized component may be a horizontally polarized component, or vice versa. In some examples, the antenna may receive a circularly polarized signal and capture the first linearly polarized component and the second linearly polarized component from the circularly polarized signal. For example, the antenna may be a dual-polarized antenna that detects the first linearly polarized component and the second linearly polarized component.

[0078] Hardware processor 402 may execute instructions 410 to identify a signal having a maximum signal power based on a comparison including a first linear polarization component and a second linear polarization component.

[0079] In some examples, the hardware processor 402 can execute instructions 410 to determine a first signal power of a first linear polarization component and a second signal power of a second linear polarization component. The first signal power and the second signal power can be compared to identify which signal power is the largest, and the component with the largest signal can be considered the identified signal. Figure 5 and Figure 6 Provide additional details for this example.

[0080] In another example, the hardware processor 402 may execute the instructions 410 to iteratively apply a plurality of phase delays to the first linear polarization component. Then, for each phase delay in the plurality of phase delays, the phase-delayed first linear polarization component may be combined with the second linear polarization component to generate a combined signal, and a signal power of the combined signal may be determined (e.g., for each phase-delayed first linear polarization component). Based on the determined signal power for each combined signal, a combined signal with a maximum signal power may be identified, which may be considered the identified signal. Figure 7 and Figure 8 Provide additional details for this example.

[0081] In yet another example, the hardware processor 402 may execute instructions 410 to input a first linear polarization component into a first input of a switch and a second linear polarization component into a second input of the switch. The switch may output a first combined circularly polarized signal. The inputs may then be flipped, for example, by inputting the first linear polarization component into the second input and the second linear polarization component into the first input, such that the switch outputs a second combined circularly polarized signal. The first signal power of the first combined circularly polarized signal may be compared to the second signal power of the second combined circularly polarized signal to determine which signal power is greater, and the greater signal is considered the identified signal. Figure 9 and Figure 10 Provide additional details for this example.

[0082] Hardware processor 402 may execute instructions 412 to obtain geographic coordinates for the access point from the identified signal. For example, using the signal identified by instruction 410, the receiver may demodulate the identified signal and obtain the location information encoded thereon, as described above in conjunction with Figure 1A and Figure 4 Based on the location information, the receiver can estimate the geographical location of the receiver by resolving the geographical coordinates, which can be inferred as the geographical coordinates of the network device.

[0083] As described above, the network device can take certain actions based on the acquired geographic coordinates. For example, the network device can resolve the location of other devices on the network. As another example, the network device can autonomously report its location for configuration of the U-NII frequency band for use by the network device when providing network services.

[0084] In some examples, computing platform 400 can execute a subset of instructions 406-412. For example, computing platform 400 can include an AP and a remote server. In this case, the AP can execute instructions 406-410, and the server can execute instructions 412. In another example, the AP can execute instructions 406-412. In yet another example, machine-readable storage medium 404 can be located on cloud-based storage, which can be accessed to execute instructions 406-412 at a later time when resources become available. In another example, the AP can collect signals at different times and with different settings, and then store the information for post-processing by a remote processor, which can be configured to stitch together the optimized settings after the fact of signal collection.

[0085] Figure 5 is a schematic block diagram of another example receiver 500 according to an implementation of the present disclosure.

[0086] As described above, the GNSS receiver may need to operate in different L-bands. Therefore, the receiver 500 includes a plurality of sub-receivers 505a-505n (collectively referred to herein as sub-receivers 505), each of which corresponds to a different L-band (e.g., L1, L2, L5, etc.). Figure 5 In the illustrative example of , the receiver 500 includes a first sub-receiver 505a configured to operate in a first L-band (eg, L1 band), and a second sub-receiver 505n configured to operate in a second L-band (eg, L5 band).

[0087] The first sub-receiver 505a may be substantially similar to Figure 3 The receiver 300, except that the pre-filter section 522a can be configured to remove signals outside the L1 band. Figure 1AAntenna 510a for receiving circularly polarized signals broadcast by positioning system 170) can be substantially similar to antenna 310. Antenna 510a captures the first component and the second component of the circularly polarized signal and transmits the components to front end 520a via first component path 512a and second component path 514a, respectively. Pre-filter section 522a includes filter 523a and filter 525a, which filter 523a and filter 525a function to filter the first component and the second component, as described above in conjunction with Figure 4 The filtered signal may be provided to a pre-amplifier section 524a, which includes an LNA 527a and an LNA 529a, each configured to amplify the filtered component. The amplified component is provided to a processing engine 530, which is substantially similar to the processing engine 330 described above.

[0088] The second sub-receiver 505n can be substantially similar to the sub-receiver 505a, except that the pre-filter section 522n can be configured to remove signals outside the L5 band. Figure 1A Antenna 510n, which receives a circularly polarized signal broadcast by positioning system 170 (e.g., a location system), can be substantially similar to antenna 510a. Antenna 510n captures the first and second components of the circularly polarized signal and communicates them to front end 520n via first component path 512n and second component path 514n, respectively. Pre-filter section 522n includes filter 523n and filter 525n, which function to filter the first and second components, as described above. The filtered signal is provided to pre-amplifier section 524n, which includes LNA 527n and LNA 529n, each configured to amplify the filtered components. The amplified components are provided to processing engine 530, which is substantially similar to processing engine 330, as described above.

[0089] Figure 6 is a flow chart of an example calibration process 600 according to an example implementation. The process 600 may be implemented as instructions stored in a memory that may be executed by a controller (e.g., a controller of the processing engine 330) to calibrate Figure 3 Receiver 500, and Figure 5 The calibration process 600 may be performed by a receiver (or sub-receiver) to select a signal to use when determining the location of the receiver based on a positioning signal (e.g., positioning signal 174A-positioning signal 174C) from a positioning system.

[0090] At block 602, a calibration mode may be triggered. For example, a controller of a receiver (or sub-receiver) may cause the receiver to enter calibration mode. For example, a circularly polarized signal may be received at an antenna (e.g., antenna 310, antenna 510a, and / or antenna 510b), and a linearly polarized component of the circularly polarized signal may be detected. In some examples, as described above, the linearly polarized component of the circularly polarized signal may be amplified and directed to a processing engine for down-conversion and demodulation to obtain location information contained therein, as described above. Prior to down-conversion and demodulation, the receiver (or sub-receiver) may enter calibration mode at block 602.

[0091] At block 604, the calibration time window (T C ) reads the first linear polarization component of the circularly polarized signal to obtain a first signal power. For example, a receiver (or a sub-receiver depending on the implementation) using an antenna can detect the first linear polarization component (e.g., a vertical linear polarization component) and measure the signal power of the first linear polarization component over a calibration time window. The calibration time window can be pre-set at a first time scale (e.g., 10 seconds, 20 seconds, 1 minute, etc.). In some examples, the first linear polarization component can be communicated to the processing engine via the first component path, as described above in conjunction with Figure 3 and Figure 5 As described. Thus, the first signal power can be measured based on the signal output by the LNA, or measured before amplification by the LNA. The signal power herein can be provided as one or more of a receiver signal level (RSSI) and a carrier-to-noise (C / N) level. Thus, for example, the processing engine 330 can receive the read output from the front end 320 and provide an RSSI value and / or a C / N value.

[0092] At block 606, the calibration time window (T C ) reads the second linear polarization component of the circularly polarized signal to obtain a second signal power. For example, a receiver (or a sub-receiver depending on the implementation) using an antenna can detect the second linear polarization component (e.g., a horizontal linear polarization component) and measure the signal power of the second linear polarization component over a calibration time window. In some examples, the second linear polarization component can be communicated to the processing engine via a second component path, as described above in conjunction with Figure 3 and Figure 5 As described above, the second signal power can be measured based on the signal output by the LNA, or can be measured before amplification by the LNA.

[0093] At determination block 608, the first signal power is compared to the second signal power to determine whether the first signal power is greater than the second signal power. If the determination is positive, the calibration process 600 proceeds to block 610, where the first linear polarization component can be selected. However, if the determination is negative, the calibration process 600 proceeds to block 612 to select the second linear polarization component. For example, the controller can determine that the first signal power is greater than the second signal power, identify the first signal power as being used for acquiring positioning information (e.g., having the maximum signal power), and select the linear polarization component corresponding to the identified signal power.

[0094] At block 614, the linear polarization component selected at block 610 or block 612 may be used to obtain location information. For example, the controller may perform down-conversion and demodulation of the selected linear polarization component to obtain the location information contained thereon and resolve the geographic coordinates of the receiver, as described above.

[0095] At decision block 616, a determination is made regarding the measurement time window (T P ) has passed. P ) can be preset to define the amount of time until the receiver may need to be recalibrated. For example, as a positioning system's satellites orbit the earth, the satellite's location changes relative to a receiver (particularly a stationary receiver). As the satellite's location changes, the traversal path of the positioning signal transmitted from the satellite to the receiver changes, which may cause a change in the number of reflections and / or a change in the signal strength of the circularly polarized signal. Additionally, as the location changes due to the orbit, the satellite from which the signal is received may change (e.g., a signal from a given satellite may no longer be received, and a signal from a new satellite may be received). These changes may affect which linear polarization component provides greater signal power, such that the receiver may need to be recalibrated to ensure that the optimal linear polarization component is used to acquire location information. As such, the measurement time window (T P ) can be set to a second time scale that is larger than the first time scale to allow for changes in position. In some cases, the measurement time window (T P ) can be set to 30 minutes or more, for example, 1 hour, 4 hours, 5 hours, etc. In some examples, the measurement time window (T P ) does not need to be constrained by the first time scale. In this case, the measurement time window (T P ) can be on the order of seconds or milliseconds.

[0096] If the determination at determination block 616 is negative, the calibration process 600 returns to block 614 and continues to use the linear polarization component selected at block 612 or at block 610. However, if the determination is positive, the calibration process 600 returns to block 602 and triggers the calibration mode to recalibrate the receiver (or sub-receiver).

[0097] In one example, for each measurement time window (T P ) and the stored determinations for post-processing to repeat process 600. In this case, process 600 may not select a component for obtaining location information until the stored determinations are processed to identify the largest component signal from the scan. Process 600 may then use that component signal to obtain location information.

[0098] Figure 7 is a schematic block diagram of another example receiver 700 according to an implementation of the present disclosure. The receiver 700 may be substantially similar to Figure 3 The receiver 300, in addition to providing a phase calibration mechanism 716 and a combiner 718 along at least one of the component paths. Thus, the receiver receives the signal generated by the positioning system (e.g., Figure 1A Antenna 710 for broadcasting circularly polarized signals from positioning system 170) can be substantially similar to antenna 310. Similarly, RF front end 720, pre-filter section 722, filter 723, pre-amplifier section 724, LNA 727, and processing engine 730 can each be substantially similar to Figure 3 RF front end 320, pre-filter section 322, filter 323, pre-amplifier section 324, LNA 327, and processing engine 330.

[0099] exist Figure 7 In the example of FIG, a phase calibration mechanism 716 is provided along the first component path 712, and a combiner 718 is connected to the first component path 712 and the second component path 714. The phase calibration mechanism 716 can be configured to adjust the phase of the first component of the circularly polarized signal received by the antenna 710, thereby causing a phase delay on the first component. The antenna 710 can be substantially similar to the antenna 310 and / or the antenna 510a. The phase calibration mechanism 716 can include a combination of inductor and capacitor circuits and / or different transmission line lengths that introduce a phase delay. In some examples, the phase calibration mechanism 716 can be a semiconductor-based phase delay integrated circuit. Although the examples herein depict the phase calibration mechanism 716 as provided on the first component path 712, in another example, the phase calibration mechanism 716 can be provided on the second component path 714 to delay the phase of the second component.

[0100] Combiner 718 can be configured to generate a combined circularly polarized signal based on combining the phase-delayed first component with the second component. For example, combiner 718 receives two components from the first component path and the second component path at input and outputs a combined circularly polarized signal at output. In an illustrative example, combiner 718 can be an RHCP combiner that generates a combined RHCP signal by combining the phase-delayed first component with the second component. In this case, the first component can lag behind the second component due to the phase delay, and the resulting combined signal has an RHCP. In another example, combiner 718 can generate a combined LHCP signal.

[0101] Furthermore, as described above, the receiver may need to operate in a different L-band. Thus, the receiver may include a plurality of sub-receivers, each of which is substantially similar to Figure 7 In the receiver 700 shown, each of the plurality of sub-receivers corresponds to a different L-band (eg, L1, L2, L5, etc.), similar to Figure 5 Example shown.

[0102] Figure 8 is a flow chart of another example calibration process 800 according to an example implementation. The process 800 may be implemented as instructions stored in a memory that may be executed by a controller (e.g., a controller of the processing engine 730) to calibrate Figure 7 Receiver 700. Calibration process 800 may be performed by a receiver (or sub-receiver) to select a signal to use when determining the location of the receiver based on positioning signals from a positioning system (eg, positioning signals 174A-174C).

[0103] At block 802, a calibration mode may be triggered. For example, a controller of a receiver (or sub-receiver) may cause the receiver to enter calibration mode. For example, a circularly polarized signal may be received at an antenna (e.g., antenna 710), and a linearly polarized component of the circularly polarized signal may be detected (block 804). In some examples, as described above, the linearly polarized component of the circularly polarized signal may be amplified and directed to a processing engine for down-conversion and demodulation to obtain location information contained therein, as described above. Prior to down-conversion and demodulation, the receiver (or sub-receiver) may enter calibration mode at block 802.

[0104] At block 804, for the calibration time window (T C) reads the first component and the second component. For example, a receiver using an antenna (or a sub-receiver depending on the implementation) can detect the first linear polarization component and the second linear polarization component (e.g., horizontal linear polarization component) over a calibration time window. The calibration time window can be pre-set at a first time scale (e.g., 10 seconds, 20 seconds, 1 minute, etc.).

[0105] At block 806, a phase offset value and a maximum sweep value may be set. In an example, the phase offset value may be set to zero, and the maximum sweep value may be set to 180 degrees. In some cases, block 806 may also include setting a step value for incrementing the phase offset value. In some examples, the step value may be set to 5 degrees, but other step values may be used depending on the desired granularity.

[0106] At block 808, a combined circularly polarized signal may be generated and the signal power of the combined circularly polarized signal may be measured. For example, the first component and the second component may be passed to a combiner 718 and combined by the combiner 718 to output a circularly polarized signal (e.g., RHCP in some examples). Note that at the first instance, the phase calibration mechanism 716 is set to zero and the phase of the first component for the first instance is not adjusted. In an example, measuring the signal power may include measuring the total power (e.g., RSSI) of the energy of the combined circularly polarized signal. In another example, measuring the signal power may include evaluating a C / N value of a decoded satellite or multiple satellites.

[0107] At determination block 810, the measured signal power is compared to the previous signal power to determine whether the current measured signal power is greater than the previous signal power. If so, the current phase offset value is stored in the memory of the processing engine 730 at block 812, and the phase offset value is incremented by the step size at block 814. If the current signal power is less than the previous signal power, the phase offset value is incremented by the step size at block 814 without saving the current phase offset value.

[0108] At decision block 816, the current phase offset value is compared to the maximum sweep value to determine if the sweep is complete. If not, the calibration process 800 returns to block 808 and repeats blocks 808-816 for the next step length value incremented by block 816.

[0109] Otherwise, the calibration process 800 proceeds to block 818 and uses the combined circularly polarized signal generated based on the stored phase offset value to acquire location information. That is, by iteratively incrementing the phase offset value and storing the phase offset value associated with the maximum signal power, the circularly polarized signal with the maximum signal power can be identified and selected for use in acquiring location information. The controller can downconvert and demodulate the selected circularly polarized signal to acquire the location information contained therein and resolve the geographic coordinates of the receiver, as described above.

[0110] At decision block 820, a determination is made regarding the measurement time window (T P ) has passed. P ) can be pre-set to define the amount of time until the receiver may need to be recalibrated. Block 820 may be substantially similar to Figure 6 6. If the determination at determination block 820 is negative, the calibration process 800 returns to block 818 and continues to use the combined circularly polarized signal to acquire location information. However, if the determination is positive, the calibration process 800 returns to block 802 and triggers the calibration mode to recalibrate the receiver (or sub-receiver).

[0111] Note that no matter how many reflections the satellite signal undergoes, the calibration process 800 will pick up two linear components and process them separately, and calibrate one of the two linear components to change its phase to generate a combined circularly polarized signal. In an implementation where the receiver 700 is included in an AP, the AP is generally a stationary device, and therefore the surrounding environment does not change much over time, and the reflected waves picked up by the antenna can have the same behavior over time.

[0112] Figure 9 is a schematic block diagram of another example receiver 900 according to an implementation of the present disclosure. The receiver 900 may be substantially similar to Figure 3 The receiver 300 includes a switch 916 and a circular polarization combiner 918 provided along the first component path 912 and the second component path 914. Thus, the receiver receives the signal transmitted by the positioning system (e.g., Figure 1A Antenna 910 for broadcasting circularly polarized signals from positioning system 170) can be substantially similar to antenna 310. Similarly, RF front end 920, pre-filter section 922, filter 923, pre-amplifier section 924, LNA 927, and processing engine 930 can each be substantially similar to Figure 3 RF front end 320, pre-filter section 322, filter 323, pre-amplifier section 324, LNA 327, and processing engine 330.

[0113] exist Figure 9In the example of , switch 916 can connect two inputs to two outputs. Switch 916 can be controlled to change its configuration to flip which input is connected to which output. Figure 9 As shown, the first component path 912 can be connected to the first input, while the second component path 914 can be connected to the second input. The first output 911 and the second output 913 can be connected to the circular polarization combiner 918. The switch 916 can be implemented as, for example, a DPDT diamond configuration switch, or any switch capable of taking two inputs and interchangeably connecting the two inputs to two outputs.

[0114] In a first configuration, a first input may connect the first component path 912 to the first output 911 such that the first component is passed to the first output 911 , and a second input may connect the second component path 914 to the second output 913 such that the second component is passed to the second output 913 .

[0115] Switch 916 can be controlled to change to a second configuration in which the output is flipped. For example, in the second configuration, the first input can connect the first component path 912 to the second output 913 so that the first component is passed to the second output 913, and the second input can connect the second component path 914 to the first output 911 so that the second component is passed to the first output 911.

[0116] The circular polarization combiner 918 may have a first input connected to the first output 911 and a second input connected to the second output 913. The circular polarization combiner 918 may be similar to Figure 7 Combiner 718 is configured such that circularly polarized combiner 918 is configured to generate a combined circularly polarized signal based on combining the first component and the second component at the input and generating a combined circularly polarized signal at the output of circularly polarized combiner 918. When switch 916 is in a first configuration, the first component on first output 911 is combined with the second component on second output 913 to generate a first circularly polarized signal. However, when switch 916 is in a second configuration, the second component on first output 911 is combined with the first component on second output 913 to generate a second circularly polarized signal having an opposite rotational direction as the first circularly polarized signal. For example, where the first component is vertically linearly polarized and the second component is horizontally linearly polarized, the first circularly polarized signal may have an RHCP when switch 916 is in the first configuration, and the second circularly polarized signal may have an LHCP when switch 916 is in the second configuration.

[0117] Furthermore, as described above, the receiver may need to operate in a different L-band. Thus, the receiver may include a plurality of sub-receivers, each of which is substantially similar to Figure 9In the receiver 900 shown, each of the plurality of sub-receivers corresponds to a different L-band (e.g., L1, L2, L5, etc.), similar to Figure 5 Example shown.

[0118] Figure 10 is a flow chart of another example calibration process 1000 according to an example implementation. Process 1000 may be implemented as instructions stored in a memory that may be executed by a controller (e.g., a controller of processing engine 930) to calibrate Figure 9 Receiver 900. Calibration process 1000 may be performed by a receiver (or sub-receiver) to select a signal to use when determining the location of the receiver based on positioning signals from a positioning system (eg, positioning signals 174A-174C).

[0119] At block 1002, a calibration mode can be triggered. For example, a controller of a receiver (or sub-receiver) can cause the receiver to enter calibration mode. For example, a circularly polarized signal can be received at an antenna (e.g., antenna 910) and a linearly polarized component of the circularly polarized signal can be detected. In some examples, as described above, the linearly polarized component of the circularly polarized signal can be amplified and directed to a processing engine for down-conversion and demodulation to obtain location information contained therein, as described above. Prior to down-conversion and demodulation, the receiver (or sub-receiver) can enter calibration mode at block 1002.

[0120] At block 1004, the switches may be configured in a first configuration. For example, as described above, the switch 916 may be controlled via the processing engine 930 to connect the first component path 912 to the first output 911 and the second component path 914 to the second output 913. In this configuration, for the calibration time window (T C ), the first component may be delivered to a first output 911, and the second component to a second output 913. As described above, the calibration time window may be pre-set at a first time scale (eg, 10 seconds, 20 seconds, 1 minute, etc.).

[0121] At block 1006, a combined first circularly polarized signal may be generated by combining the first component and the second component. For example, the first component may be passed to a circular polarization combiner 918 via a first output 911, and the second component may be passed to the circular polarization combiner 918 via a second output 913. The first component and the second component may be combined by the circular polarization combiner 918 to output a first combined circularly polarized signal (e.g., RHCP in some examples).

[0122] At block 1008 , a first signal power of the first combined circularly polarized signal may be measured.

[0123] At block 1010, the switches may be flipped to a second configuration. For example, as described above, the switch 916 may be controlled via the processing engine 930 to connect the first component path 912 to the second output 913 and the second component path 914 to the first output 911. In this configuration, for the calibration time window (T C ), the first component can be passed to the second output 913, and the second component is passed to the first output 911.

[0124] At block 1012, a second signal power of the second combined circularly polarized signal may be measured. For example, the second combined circularly polarized signal may be generated by combining the first component and the second component. That is, the first component may be passed to the circular polarization combiner 918 via the second output 913, while the second component may be passed to the circular polarization combiner 918 via the first output 911. The first component and the second component may be combined by the circular polarization combiner 918 to output a second combined circularly polarized signal having an opposite rotational direction as the first combined circularly polarized signal (e.g., LHCP in some examples). Thus, the signal power of the second combined circularly polarized signal may be measured at block 1012.

[0125] At determination block 1014, the first signal power is compared to the second signal power to determine whether the first signal power is greater than the second signal power. If the determination is positive, the calibration process 1000 proceeds to block 1016, where a first combined circularly polarized component can be selected and the switch configured according to the first configuration. However, if the determination is negative, the calibration process 1000 proceeds to block 1018 to select a second combined circularly polarized component and configure the switch according to the second configuration.

[0126] At block 1020, the combined circular polarization component selected at block 1016 or block 1018 may be used to obtain location information. For example, the controller may perform down-conversion and demodulation of the selected combined circular polarization to obtain the location information contained thereon and resolve the geographic coordinates of the receiver, as described above.

[0127] At decision block 820, a determination is made regarding the measurement time window (T P ) has passed. P ) can be pre-set to define the amount of time until the receiver may need to be recalibrated. Block 1022 may be substantially similar to Figure 66. If the determination at determination block 1022 is negative, the calibration process 1000 returns to block 1020 and continues to acquire location information using the selected combined circularly polarized signal. However, if the determination is positive, the calibration process 1000 returns to block 1002 and triggers the calibration mode to recalibrate the receiver (or sub-receiver).

[0128] Figure 11 A block diagram of an example computer system 1100 is depicted in which various examples described herein may be implemented. 1100 may be implemented as Figure 1A The network controller 104, Figure 3 processing engine 330 or controller 332, processing engine 530a or processing engine 530b (or the controller thereof), Figure 7 Processing engine 730, and / or Figure 9 The processing engine 930 of the computer system 1100 includes a bus 1102 or other communication mechanism for communicating information, and one or more hardware processors 1104 coupled to the bus 1102 for processing information. The hardware processor(s) 1104 may be, for example, one or more general-purpose microprocessors.

[0129] The computer system 1100 also includes a main memory 1106, such as a random access memory (RAM), a cache, and / or other dynamic storage device, coupled to the bus 1102 for storing information and instructions to be executed by the processor 1104. The main memory 1106 may also be used to store temporary variables or other intermediate information during the execution of instructions to be executed by the processor 1104. When such instructions are stored in a storage medium accessible to the processor 1104, the computer system 1100 appears as a special-purpose machine that is customized to perform the operations specified in the instructions. In some examples, the main memory 1106 may store instructions that can be executed by the processor 1104 to perform operations in conjunction with Figure 4 、 Figure 6 、 Figure 8 ,and Figure 10 The described operation.

[0130] The computer system 1100 also includes a read-only memory (ROM) 1108 or other static storage device coupled to the bus 1102 for storing static information and instructions for the processor 1104. A storage device 1110, such as a magnetic disk, optical disk, or USB thumb drive (flash drive), is provided and coupled to the bus 1102 for storing information and instructions.

[0131] The computer system 1100 may be coupled to a display 1112, such as a liquid crystal display (LCD) (or touch screen), via bus 1102 for displaying information to a computer user. An input device 1114, including alphanumeric and other keys, is coupled to bus 1102 for communicating information and command selections to processor 1104. Another type of user input device is a cursor control 1116 (such as a mouse, trackball, or cursor direction keys) for communicating direction information and command selections to processor 1104 and for controlling cursor movement on display 1112. In some embodiments, the same direction information and command selections as cursor control can be implemented by receiving touches on a touch screen without a cursor.

[0132] The computing system 1100 may include a user interface module that implements a GUI, which may be stored in a mass storage device as executable software code executed by the computing device(s). For example, this module and other modules may include, by way of example, components (such as software components, object-oriented software components, class components, and task components), procedures, functions, properties, programs, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables.

[0133] In general, the terms "component," "engine," "system," "database," "data store," and the like as used herein may refer to logic embodied in hardware or firmware, or to a collection of software instructions, possibly with entry and exit points, written in a programming language (such as Java, C, or C++). Software components may be compiled and linked into an executable program installed in a dynamic link library, or may be written in an interpreted programming language (such as, for example, BASIC, Perl, or Python). It should be understood that software components may be callable from other components or from themselves, and / or may be called in response to detected events or interrupts. Software components configured for execution on a computing device may be provided on a computer-readable medium (such as an optical disc, digital video disc, flash drive, magnetic disk, or any other tangible medium), or provided as a digital download (and may initially be stored in a compressed or installable format, requiring installation, decompression, or decryption prior to execution). Such software code may be stored in part or in whole on a memory device of the executing computing device for execution by the computing device. Software instructions may be embedded in firmware (such as an EPROM). It will also be understood that hardware components may include connected logic units (such as gates and flip-flops), and / or may include programmable units (such as programmable gate arrays or processors).

[0134] The computer system 1100 can implement the techniques described herein using custom hard-wired logic, one or more ASICs or FPGAs, firmware, and / or program logic that, in combination with the computer system, enables the computer system 1100 to become, or be programmed to become, a special-purpose machine. According to one embodiment, the techniques herein are performed by the computer system 1100 in response to the processor(s) 1104 executing one or more sequences of one or more instructions contained in the main memory 1106. Such instructions can be read into the main memory 1106 from another storage medium, such as the storage device 1110. Execution of the sequences of instructions contained in the main memory 1106 causes the processor(s) 1104 to perform the process steps described herein. In alternative embodiments, hard-wired circuitry can be used in place of, or in combination with, software instructions.

[0135] As used herein, the term "non-transient medium" and similar terms refer to any medium that stores data and / or instructions that cause a machine to operate in a specific manner. Such non-transient media can include non-volatile media and / or volatile media. Non-volatile media include, for example, optical disks or magnetic disks (such as storage device 1110). Volatile media include dynamic memory, such as main memory 1106. Common forms of non-transient media include, for example, floppy disks, flexible disks, hard disks, solid-state drives, tapes, or any other magnetic data storage media, CD-ROMs, any other optical data storage media, any physical media with a pattern of holes, RAMs, PROMs, and EPROMs, FLASH-EPROMs, NVRAMs, any other memory chips or cassette tapes, and networked versions of the above.

[0136] Non-transient media are distinct from, but may be used in conjunction with, transmission media. Transmission media participate in the transfer of information between non-transient media. For example, transmission media include coaxial cables, copper wire, and optical fiber, including the wires comprising bus 1102. Transmission media may also take the form of acoustic or light waves, such as those generated during radio wave and infrared data communications.

[0137] Computer system 1100 also includes a communication interface 1118 that is coupled to bus 1102. Communication interface 1118 provides the two-way data communication that is coupled to one or more network links, and these one or more network links are connected to one or more local networks. For example, communication interface 1118 can be an integrated services digital network (ISDN) card, a cable modem, a satellite modem or a modem that is provided to connect the data communication of the telephone line of the corresponding type. As another example, communication interface 1118 can be a local area network (LAN) card, to provide the data communication connection to a compatible LAN (or the WAN component with WAN communication). Wireless link also can be implemented. In any such implementation, communication interface 1118 sends and receives the electric signal, electromagnetic signal or the optical signal that carry the digital data stream representing various types of information.

[0138] A network link typically provides data communication to other data devices through one or more networks. For example, a network link can provide a connection through a local network to a host computer or to data equipment operated by an Internet Service Provider (ISP). The ISP, in turn, provides data communication services through the global packet data communication network now commonly referred to as the "Internet." Both the local network and the Internet use electrical, electromagnetic, or optical signals that carry digital data streams. The signals through the various networks, as well as the signals on the network link and through the communication interface 1118, are example forms of transmission media that carry digital data to and from the computer system 1100.

[0139] Computer system 1100 can send messages and receive data (including program code) through the network(s), network links, and communications interface 1118. In the Internet example, a server may send the requested code for an application through the Internet, an ISP, a local network, and communications interface 1118.

[0140] The received code may be executed by processor 1104 as it is received and / or stored in storage device 1110 , or other non-volatile storage, for later execution.

[0141] Each of the processes, methods, and algorithms described in the preceding sections can be embodied in a code component executed by one or more computer systems, or computer processors comprising computer hardware, and fully or partially automated by the code component. One or more computer systems or computer processors can also operate to support the performance of related operations in a "cloud computing" environment or as a "software as a service" (SAAS). The processes and algorithms can be implemented in part or in whole in dedicated circuits. The various features and processes described above can be used independently of each other or combined in various ways. Different combinations and sub-combinations are intended to fall within the scope of this disclosure, and certain methods or processing blocks may be omitted in some implementations. The methods and processes described herein are not limited to any particular order, and the blocks or states associated therewith can be executed in other appropriate orders, or can be executed in parallel, or in some other manner. Blocks or states can be added to or removed from the disclosed example embodiments. The execution of certain operations or processes can be distributed among computer systems or computer processors, not only residing within a single machine, but also deployed across multiple machines.

[0142] As used herein, any form of hardware, software or its combination can be utilized to realize circuit.For example, one or more processors, controllers, ASIC, PLA, PAL, CPLD, FPGA, logic components, software routines or other mechanisms can be realized to constitute circuit.In realization, various circuits described herein can be realized as discrete circuits, or described function and feature can be shared partly or entirely between one or more circuits.Even if various features or functional elements can be described or declared as separated circuits individually, these features and functions can be shared between one or more common circuits, and such description should not require or imply that the circuit needs to be separated to realize such feature or function.When using software to realize circuit wholly or in part, such software can be realized as, with the computing or processing system (such as, computer system 1100) that can perform about its described function, operate together.

[0143] As used herein, the term "or" may be interpreted in an inclusive or exclusive sense. In addition, descriptions of resources, operations, or structures in the singular should not be interpreted as excluding the plural. Unless otherwise expressly stated or otherwise understood within the context of use, conditional language (such as "can," "can," "might," or "may," among others) is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and / or steps.

[0144] Unless expressly stated otherwise, the terms and phrases used in this document and their variations should be interpreted as open-ended and non-restrictive. Adjectives such as "conventional," "traditional," "normal," "standard," "known," and terms of similar meaning should not be interpreted as limiting the items described to items available in a given time period or at a given time, but should be interpreted as covering conventional, traditional, normal, or standard technologies available or known at any time now or in the future. In some instances, the presence of meaning-expanding words and phrases such as "one or more," "at least," "but not limited to," or other similar phrases should not be interpreted as meaning that a narrower meaning is intended or required in instances where such meaning-expanding phrases may not be present.

Claims

1. A method for tuning an access point, comprising: Receiving a circularly polarized signal by an antenna of the access point; Acquire a first linear polarization component of the circularly polarized signal and a second linear polarization component of the circularly polarized signal; identifying a signal having a maximum signal power based on a comparison comprising the first linearly polarized component and the second linearly polarized component; obtaining geographic coordinates for the access point from the identified signal; as well as Connecting to a network is performed based on the obtained geographic coordinates. The method according to claim 1 , wherein the circularly polarized signal is a right-hand circularly polarized signal. The method according to claim 2 , wherein the circularly polarized signal is a Global Navigation Satellite System (GNSS) signal. The method of claim 1 , wherein the first linear polarization component is orthogonal to the second linear polarization component.

5. The method according to claim 1, further comprising: determining that the first signal power is greater than the second signal power by comparing a first signal power of the first linear polarization component with a second signal power of the second linear polarization component, The identified signal is the first linear polarization component.

6. The method according to claim 1, further comprising: iteratively applying a plurality of phase delays to the first linear polarization component; For each phase delay of the plurality of phase delays, combining the phase-delayed first linear polarization component and the second linear polarization component to generate a combined signal, and determining a signal power of the combined signal; as well as identifying a combined signal of the plurality of phase delays, the combined signal having the maximum signal power, The identified signal is the identified combined signal. The method of claim 6 , wherein the combined signal is a circularly polarized signal.

8. The method according to claim 1, further comprising: inputting the first linear polarization component to a first input of a switch, and inputting the second linear polarization component to a second input of the switch to output a first combined circularly polarized signal; inputting the first linear polarization component to the second input of the switch, and inputting the second linear polarization component to the first input of the switch to output a second combined circularly polarized signal; as well as By comparing a first signal power of the first combined circularly polarized signal with a second signal power of the second combined circularly polarized signal, determining that the first signal power is greater than the second signal power, The identified signal is the first combined circularly polarized signal. 9 . The method of claim 8 , wherein the first combined circularly polarized signal is a right-hand circularly polarized signal, and wherein the second combined circularly polarized signal is a left-hand circularly polarized signal.

10. An access point, comprising: antenna; a memory storing instructions; as well as at least one processor communicatively coupled to the antenna and the memory and configured to execute the instructions to: The antenna receives a positioning signal from a positioning system, wherein the positioning signal includes a right-hand circularly polarized signal; Acquire a first linear polarization component of the positioning signal and a second linear polarization component of the positioning signal; selecting a signal having a maximum signal power based on a comparison including the first linear polarization component and the second linear polarization component; determining geographic coordinates for the access point based on the selected signal; as well as A network service is provided based on the acquired geographic coordinates. The access point of claim 10 , wherein the antenna is a dual-polarized antenna.

12. The access point of claim 10, wherein the positioning signal is a Global Navigation Satellite System (GNSS) signal.

13. The access point of claim 10, wherein the first linear polarization component is a vertical linear polarization component, and the second linear polarization component is a horizontal linear polarization component.

14. The access point of claim 10, wherein the at least one processor is further configured to execute the instructions to: determining that the first signal power is greater than the second signal power by comparing a first signal power of the first linear polarization component with a second signal power of the second linear polarization component, The selected signal is the first linear polarization component.

15. The access point according to claim 10, further comprising: a phase calibration mechanism connected to the antenna; as well as A combiner is connected to the phase calibration mechanism.

16. The access point of claim 15, wherein the at least one processor is further configured to execute the instructions to: applying, by the phase calibration mechanism, a plurality of phase delays iteratively to the first linear polarization component; For each phase delay of the plurality of phase delays, combining, by the combiner, the phase-delayed first linear polarization component and the second linear polarization component to generate a combined signal, and determining a signal power of the combined signal; and identifying a combined signal of the plurality of phase delays, the combined signal having the maximum signal power, The selected signal is the identified combined signal.

17. The access point of claim 10, further comprising: a switch comprising a first input and a second input connected to the antenna; as well as A circular polarization combiner has a first input connected to the first output of the switch and a second input connected to the second output of the switch.

18. The access point of claim 17, wherein the at least one processor is further configured to execute the instructions to: The switch is configured in a first configuration, wherein When in the first configuration, the first linearly polarized component is passed into the first input of the switch, and the second linearly polarized component is passed into the second input of the switch in the first configuration; outputting a first combined circularly polarized signal from the circularly polarized combiner when the switch is in the first configuration; configuring the switch in a second configuration, wherein, when in the second configuration, the first linearly polarized component is passed into the second input of the switch and the second linearly polarized component is passed into the first input of the switch; outputting a second combined circularly polarized signal from the circularly polarized combiner when the switch is in the second configuration; and By comparing a first signal power of the first combined circularly polarized signal with a second signal power of the second combined circularly polarized signal, determining that the first signal power is greater than the second signal power, The selected signal is the first combined circularly polarized signal.

19. A global navigation satellite system (GNSS) receiver, comprising: a dual-polarization antenna configured to detect a first linear polarization component of a GNSS signal and a second linear polarization component of the GNSS signal; as well as A controller is connected to the dual-polarized antenna, the controller being configured to select an optimal signal based on a comparison including the first linear polarization component and the second linear polarization component, and to resolve geographic coordinates using the optimal signal.

20. The GNSS receiver of claim 19, wherein selecting the optimal signal is based on identifying a signal having a maximum signal power based on the comparison comprising the first linear polarization component and the second linear polarization component.

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