Adaptive single-element antenna device and operating method thereof

Abstract

The present invention relates to an adaptive single-element antenna device and an operating method thereof. The device includes an antenna assembly, the antenna assembly comprising: an antenna configured to receive a signal and generate a plurality of corresponding polarized signals having different polarization directions at a plurality of feed points of the antenna using the received signal; and a switching circuit configured to periodically switch between the plurality of feed points to select a corresponding one of the plurality of polarized signals at a time point based on a switching signal.

Description

Technical Field

[0001] The present disclosure relates generally to antennas and, more particularly, to devices and methods of operating the same that include an antenna assembly capable of switching between multiple feed points and a receiver capable of processing signals from the antenna assembly in conjunction with the switching. Background Art

[0002] A Global Navigation Satellite System (GNSS) receiver receives satellite signals transmitted from a GNSS satellite constellation via an antenna. Before reaching the antenna, the satellite signals may be scattered, reflected, or refracted in space, for example by mountains or buildings, causing multipath interference at the antenna. Alternatively, the antenna may be subject to spoofing attacks that trick the receiver with false signals. Alternatively, the antenna may be subject to noise broadcast from a jammer on the same frequency used by one or more satellites in the GNSS satellite constellation.

[0003] Multipath interference, spoofing, and jamming can be mitigated through null steering, where the GNSS receiver steers away from unwanted signals in one direction and focuses on another. Null steering can be achieved by adding hardware (e.g., a multi-antenna array) in the front end of the receiver and additional signal processing blocks in the back end of the receiver. However, this increases the size and cost of the receiver. Summary of the Invention

[0004] According to some embodiments of the present disclosure, a device is provided. The device includes an antenna assembly, comprising: an antenna configured to receive a signal and generate, at multiple feeding points of the antenna, a plurality of corresponding polarized signals having different polarization directions using the received signal; and a switching circuit configured to periodically switch between the multiple feeding points to select a corresponding one of the multiple polarized signals at a time point based on a switching signal.

[0005] According to some embodiments of the present disclosure, a method for operating a device is also provided, wherein the device includes an antenna configured to receive a signal and generate multiple polarized signals having respective polarization directions different from each other. The method includes the following steps: generating a switching signal; controlling a switch in the antenna based on the generated switching signal; using the switch to time-division multiplex the multiple polarized signals; determining a desired amplitude and a desired phase for each of the multiple polarized signals; assigning a complex weight to each of the multiple polarized signals, wherein the complex weight includes an amplitude weight and a phase weight; and correlating the multiple time-division multiplexed polarized signals.

[0006] According to some embodiments of the present disclosure, a non-transitory computer-readable medium storing instructions is also provided, which, when executed by a processor, performs a method for controlling a device, the method comprising: generating a switching signal by the device; sending the generated switching signal to an antenna component so that the switching signal drives a switch in the antenna component; receiving a time-division multiplexed signal from the antenna component that is generated by periodically selecting a polarization signal from a plurality of polarization signals based on the switching signal; determining, by the device, a desired amplitude and a desired phase for each of the plurality of polarization signals; assigning, by the device, a complex weight to each of the plurality of polarization signals, wherein the complex weight includes an amplitude weight and a phase weight; and correlating, by the device, the plurality of time-division multiplexed polarization signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic diagram illustrating a device including an antenna assembly and a receiver consistent with some embodiments of the present disclosure.

[0008] Figure 2 is a flow chart illustrating an exemplary method for operating an apparatus consistent with some embodiments of the present disclosure.

[0009] Figure 3 is a block diagram of an apparatus consistent with some embodiments of the present disclosure. DETAILED DESCRIPTION

[0010] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, in which, unless otherwise indicated, like reference numerals in different figures represent like or similar elements. The implementations set forth in the following description of the exemplary embodiments are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of systems, devices, and methods consistent with aspects of the present disclosure as set forth in the appended claims.

[0011] Multipath interference poses a significant problem in GNSS navigation solutions, particularly in complex propagation environments (e.g., mountains, buildings, urban canyons, foliage, etc.). GNSS satellites transmit right-hand circularly polarized (RHCP) electromagnetic waves. However, in complex propagation environments, the rotational direction of the electric field vector of RHCP electromagnetic waves can change due to the interaction between the electromagnetic waves and the environment. This can make it difficult to determine the polarization of electromagnetic waves transmitted in complex propagation environments.

[0012] Spoofing or jamming attacks are another challenge in GNSS navigation solutions. For example, spoofing signals sent from unknown sources attempt to deceive GNSS receivers. Jamming signals transmitted on the same frequency as signals transmitted by GNSS satellites degrade the GNSS receiver's ability to receive GNSS satellite signals. Therefore, multipath interference, spoofing, and jamming are significant threats to autonomous vehicles that rely on trustworthy global position information.

[0013] Multipath interference, spoofing, and jamming in GNSS receivers can be mitigated through null steering or beam steering, in which the GNSS receiver blocks unwanted signals from one direction or focuses on desired signals from another. Zero steering (or beam steering) can be implemented by adding hardware to the front end of the receiver (e.g., using a multi-antenna array) and adding additional signal processing blocks to the back end of the receiver. However, this increases the size of the system and increases the cost of system design. Furthermore, zero steering can only be performed globally, i.e., applying zero steering to all satellite signals simultaneously, which affects the accuracy and flexibility of the mitigation.

[0014] Embodiments of the present disclosure provide a device including an antenna assembly and a receiver. The antenna assembly includes an antenna having multiple feed points that generate multiple polarized signals having different polarization directions. The antenna assembly also includes a switching circuit including a switch that periodically switches between the multiple feed points to select a corresponding polarized signal from the multiple polarized signals at a given time point to form a time-division multiplexed signal. The receiver generates a switching signal to control the switch in the antenna assembly. The time-division multiplexed signal is filtered and amplified in the antenna assembly and then transmitted to the receiver. The receiver processes the time-division multiplexed signal in the digital domain and controls the generation of the switching signal based on the processing. For example, the receiver determines a desired amplitude and a desired phase for each of the multiple polarized signals and assigns a complex weight to each of the multiple polarized signals based on the desired amplitude and phase determined for each polarized signal. The receiver includes a correlator having multiple correlator channels. Each of the multiple correlator channels is assigned to a different signal from a plurality of signals transmitted from a plurality of different satellites. Each of the plurality of correlator channels independently processes a corresponding one of the plurality of satellite signals.

[0015] The embodiments disclosed herein have one or more technical effects. By using switches to switch between multiple antenna feed points, time-division multiplexing multiple signals with different polarization directions, and processing the time-division multiplexed signals in the digital domain in the receiver, the need for hardware reorganization of polarization signals in the RF domain is eliminated, resulting in reduced size, reduced cost, and reduced power consumption of the receiver. Performing filtering and amplification of the time-division multiplexed signals in the antenna assembly rather than in the receiver enhances operational resistance to temperature fluctuations. By determining a desired phase and a desired amplitude for each of the multiple polarization signals and assigning a complex weight including the desired phase and the desired amplitude to each of the multiple polarization signals, zero steering is achieved during signal correlation. By assigning each of the multiple correlator channels to a different one of the multiple signals transmitted from multiple different satellites and applying a complex weight to each signal in each of the multiple correlator channels, zero steering is performed individually for each satellite signal, resulting in enhanced accuracy in mitigating multipath interference, jamming, and spoofing.

[0016] Figure 1 is a schematic diagram illustrating a device 100 including an antenna assembly and a receiver consistent with some embodiments of the present disclosure. Figure 1 , the device 100 includes an antenna assembly 110, a receiver 160, and an antenna cable 140 connecting the antenna assembly 110 and the receiver 160. The antenna assembly 110 includes an antenna 112 and a switching circuit 122. The antenna 112 is configured to receive a GNSS signal 114. In an embodiment, the GNSS signal 114 may be a single satellite frequency band signal transmitted from a single satellite. The single satellite signal may have a corresponding pseudo-random noise (PRN) code. In another embodiment, the GNSS signal 114 may include multiple satellite signals respectively transmitted from multiple satellites, and each of the multiple satellite signals may have a corresponding PRN code. In an embodiment, the GNSS signal 114 may also include signals originating from one or more virtual sources that reflect and / or scatter satellite signals. In an embodiment, the GNSS signal 114 may include a satellite signal reflected at an interface between two media. However, the signal received by the antenna 112 is not limited to a satellite signal and may be any electromagnetic wave (e.g., a wireless cellular signal) transmitted from any source.

[0017] Antenna 112 includes a first feed point (not shown) that generates a first polarized signal 116, a second feed point (not shown) that generates a second polarized signal 118, and a third feed point (not shown) that generates a third polarized signal 120. In an embodiment, the polarizations of first polarized signal 116, second polarized signal 118, and third polarized signal 120 may form three orthogonal modes, for example, a transverse magnetic 01 (TM01) mode, a transverse magnetic 10 (TM10) mode, and a transverse magnetic 11 (TM11) mode. However, the number of feed points in antenna 112 is not limited to three and may be any other number, for example, two or any number greater than three. Antenna 112 may be any antenna that can have multiple feed points (for example, a patch antenna, a helical antenna, a crossbow antenna, an orthogonally positioned monopole antenna, etc.).

[0018] The polarization at multiple feed points in antenna 112 can be described using a complex vector (i.e., a polarization vector) representing the direction of the electric field. For three feed points, the polarization vectors can be configured so that they are orthogonal to each other. For more than three feed points, the polarization vectors can be configured so that they can be orthogonalized to achieve a vector rank of 3.

[0019] Switching circuit 122 includes a switch 124 that periodically switches between the first, second, and third feed points to select a polarization signal from each of first polarization signal 116, second polarization signal 118, and third polarization signal 120 at a given time point for sampling to form a time-division multiplexed signal. The resulting time-division multiplexed signal is a combination of the sampled first polarization signal 116, the sampled second polarization signal 118, and the sampled third polarization signal 120, forming a single signal path. Switching can be performed at a sufficiently high rate so that the sampled signals can be recovered through signal processing at receiver 160. For example, the switching period can be less than 1 ms. Switching in switch 124 is controlled by a switching signal generated by switching signal generator 130 of receiver 160 and transmitted via antenna cable 140.

[0020] The switching circuit 122 may include a switching signal detector 134 that detects the switching signal. The switching signal detector 134 may be selected based on the type of the switching signal. For example, if the switching signal consists of different amplitude levels, a comparator may be used as the switching signal detector.

[0021] Switching circuit 122 may include a low-noise amplifier (LNA) 126, coupled to switch 124 and configured to amplify the time-division multiplexed signal. LNA 126 may be supplied with a direct current (DC) bias provided by receiver 160. A low-pass filter (LPF) 132 may be implemented in the DC bias path to filter out the switching signal superimposed on the DC bias before supplying the DC bias to LNA 126. In an embodiment, LNA 126 may include a controller for controlling parameters of the amplified signal. The parameters may include at least one of: gain, noise, linearity, bandwidth, output dynamic range, slew rate, rise rate, overshoot, or stability factor.

[0022] Switching circuit 122 may include a bandpass filter (BPF) 128 coupled to LNA 126 and configured to filter the amplified signal to suppress frequencies outside a range of interest. The filtered and amplified time division multiplexed (TDM) signal is then transmitted via antenna cable 140 to receiver 160 and is shown as TDM signal 176 for further processing by receiver 160 in the digital domain.

[0023] Antenna cable 140 electrically connects antenna assembly 110 and receiver 160 to transmit time-division multiplexed signals from antenna assembly 110 to receiver 160, and to transmit switching signals and DC bias signals from receiver 160 to antenna assembly 110. Antenna cable 140 may be a coaxial RF cable or any other cable suitable for transmitting RF signals.

[0024] By using switches to switch between multiple antenna feed points and time-division multiplexing signals with different polarization directions, and processing the time-division multiplexed signals in the digital domain at the receiver, the need to reconstruct the differently polarized signals in the RF domain is eliminated. This allows for a reduction in size, cost, and power consumption of device 100. Furthermore, filtering and amplifying the time-division multiplexed signals at the antenna and digitally processing the signals at the receiver enhances the robustness of signal reception and processing to temperature fluctuations.

[0025] In an embodiment, at least one of the LNA 126 and the BPF 128 may be implemented on the receiver side rather than the antenna side. In another embodiment, both the receiver 160 and the antenna assembly 110 include an LNA and a BPF.

[0026] Receiver 160 includes a biaser (bias-T) circuit 174 that provides a DC bias signal that is superimposed on the switching signal and sent via antenna cable 140 to LNA 126 of switching circuit 122 of antenna assembly 110 .

[0027] The receiver 160 includes a switching signal generator 130 that generates a switching signal that drives the switching circuit 122 of the antenna assembly 110. The switching signal generator 130 can be a pulse signal generator or an AC signal generator. The switching signal can be a synchronization signal formed by mixing the signal generated by the switching signal generator 130 with a local oscillation signal provided by a local oscillator (not shown). The switching period can be approximately 1 ms.

[0028] In an embodiment, the generated switching signal includes a plurality of signals having respective frequencies different from one another. A corresponding one of the plurality of switching signals having respective frequencies different from one another is provided to each of the plurality of polarization signals.

[0029] In another embodiment, the switching signal may include multiple signals having different corresponding signal magnitudes. A corresponding one of the multiple switching signals having different corresponding signal magnitudes is provided to each of the multiple polarization signals. For example, the switching signal may be a pulse signal including multiple pulses having different corresponding magnitudes.

[0030] In an embodiment, a power supply bias may be added to the generated switching signal such that a positive pulse drives switching while a negative pulse resets the switching sequence, and vice versa.

[0031] The generated switching signal is then sent to the switching circuit 122 of the antenna assembly 110 through the antenna cable 140. The switching signal may be superimposed on the DC bias signal for transmission to the antenna assembly 110.

[0032] Receiver 160 includes a control engine 162 that determines the desired null direction The control engine 162 may determine the desired null direction using a control loop that operates to find the location or direction of an interference source by optimizing signal levels and minimizing interference metrics in the receiver. For example, the GNSS signal 114 from the antenna 112 is a spread spectrum signal, and the control engine 162 may determine the direction of the dominant multipath interference through the operation of the control loop, and then determine the direction of the dominant multipath interference as the desired null direction. In addition to the desired null direction, the control engine 162 may also determine the beam direction.

[0033] In an embodiment, based on the determination of the desired null direction, the control engine 162 may also determine a desired amplitude and a desired phase for each of the multiple polarized signals included in the time-division multiplexed signal. In an embodiment, the control engine 162 may determine the desired amplitude and the desired phase for each of the multiple polarized signals based on the desired null direction, the desired beam direction, the direction of the interference source, the direction of the dominant multipath interference, or any combination thereof. If the antenna pattern (gain, phase, etc.) is known, the control engine 162 may determine the desired amplitude and the desired phase for each of the multiple polarized signals based on on-the-fly optimization. Alternatively, the control engine 162 may use a model, such as (but not limited to) a low-order polynomial model, to determine the desired amplitude and the desired phase for each of the multiple polarized signals.

[0034] In an embodiment, the control engine 162 may be implemented as software, and the operation of the control engine 162 may be implemented by a program stored in a computer-readable storage medium and executed by a processor. The processor may be implemented inside the receiver 160. In another embodiment, the control engine 162 may be implemented as hardware, which includes a program and a processor configured to execute the program to perform the functions of the control engine.

[0035] Receiver 160 includes a steering engine 164 that assigns complex weights to each of the multiple polarized signals included in input TDM signal 176. In an embodiment, the complex weights include amplitude weights (a1, a2, a3, etc.) and phase weights (ψ1, ψ2, ψ3, etc.) for each of the multiple polarized signals. For example, steering engine 164 may assign complex weights (a1, ψ1) to first polarized signal 116, complex weights (a2, ψ2) to second polarized signal 118, and complex weights (a3, ψ3) to third polarized signal 120.

[0036] In another embodiment, the steering engine 164 may assign a complex weight to each of the multiple polarized signals based on the desired null direction determined by the control engine 162. For example, for a known antenna pattern (gain and phase), the steering engine 164 may run an on-the-fly optimization to assign a complex weight to each of the multiple polarized signals. Alternatively, the steering engine 164 may use a model, such as a low-order polynomial model, to map the desired null direction to a complex weight for each of the multiple polarized signals. Alternatively, the steering engine 164 may obtain the complex weight corresponding to the desired null direction from a lookup table included in the receiver 160. In this embodiment, determining the desired amplitude and desired phase for each of the multiple polarized signals may not be performed by the control engine 162.

[0037] The steering engine 164 also generates a switching control signal for the switching signal generator 130. The generated switching control signal is then sent to the switching signal generator 130 and controls signal generation at the switching signal generator 130. In an embodiment, under the control of the switching control signal, the switching signal generator 130 may generate a switching signal such that the complex weight assigned to each of the first polarization signal 116, the second polarization signal 118, and the third polarization signal 120 is reflected through the operation of the switch 124.

[0038] In an embodiment, the steering engine 164 may be implemented as software, and the operation of the steering engine 164 may be implemented by a program stored in a computer-readable storage medium and executed by a processor. The processor may be a processor implemented within the receiver 160. In another embodiment, the steering engine 164 may be hardware, which includes a program and a processor configured to execute the program to perform the functions of the steering engine.

[0039] In alternative embodiments, the control engine 162 and the steering engine 164 may be combined into one operation to optimize receiver parameters, such as the carrier-to-noise density (C / N0) or signal-to-noise ratio (SNR) of the receiver 160.

[0040] Receiver 160 includes a correlator 166. Correlator 166 includes a plurality of correlator channels. Each of the plurality of correlator channels receives an input TDM signal 176. Each of the plurality of correlator channels includes a pseudorandom noise (PRN) code generator and a numerically controlled oscillator (NCO) coupled to a mixer. For example, correlator channel 1 includes a PRN code NCO 168 coupled to mixer 170. In each correlator channel, a PRN code generator generates a unique PRN code for the input TDM signal 176.

[0041] In an embodiment, the GNSS signal 114 received by antenna 112 is a signal transmitted from a single GNSS satellite, and correlator channel 1 (or any other correlator channel) is assigned to process the input TDM signal 176. The PRN code generator of correlator channel 1 generates a PRN code corresponding to the PRN code of the GNSS signal 114 from the single GNSS satellite. In correlator channel 1, mixer 170 mixes the input TDM signal 176 with the local oscillator signal generated by the NCO 168 of correlator channel 1. Complex weights assigned to each of the first polarization signal 116, the second polarization signal 118, and the third polarization signal 120 are applied to each signal. The phase weights of each signal can be applied by shifting the phase of each signal in the NCO based on the phase weights in the complex weights. The amplitude weights of each signal can be applied by adjusting the amplitude of each signal based on the amplitude weights in the complex weights. For example, in the complex weight (a1, ψ1) assigned to the first polarized signal 116, a1 may indicate an amount to be multiplied by the current amplitude of the first polarized signal 116, and ψ1 may indicate a phase shift to be applied to the current phase of the first polarized signal 116. The current amplitude and current phase of the first polarized signal 116 are adjusted based on a1 and ψ1. In this way, zero steering or beam steering can be achieved by determining a desired null direction or a desired beam direction, and assigning and applying complex weights to multiple polarized signals forming a time-division multiplexed signal during correlation.

[0042] The amplitude and / or phase adjusted polarization signals are correlated in correlator channel 1 to form an output signal for further processing. For example, the correlated multiple polarization signals can be recombined for tracking or positioning.

[0043] In another embodiment, the GNSS signal 114 received by the antenna 112 includes multiple signals transmitted from multiple different satellites. The multiple different satellites may correspond to one or more satellite frequency bands. For example, the multiple satellites may correspond to multiple satellite frequency bands. In this embodiment, each of the multiple correlator channels is assigned to a different one of the multiple satellites. For example, the receiver 160 may include a receiver manager (not shown) that assigns each of the multiple correlator channels to a different one of the multiple satellites based on multiple PRN codes corresponding to the multiple satellites. In an embodiment, the receiver manager may be implemented as software, and the operation of assigning the multiple satellite signals may be performed by a program stored in a computer-readable storage medium and executed by a processor. The processor may be a processor implemented within the receiver. In this embodiment, the control engine 162 may determine different expected null directions for the multiple correlator channels, and the steering engine 164 may assign complex weights to each of the multiple polarization signals in each correlator channel based on the expected null directions determined for each correlator channel. Each of the multiple correlator channels may independently perform signal processing on the signal received from a corresponding one of the multiple satellites. In this way, null steering may be performed locally, eg, null steering may be applied to an individual satellite rather than to multiple satellites, resulting in enhanced mitigation of multipath interference, spoofing, and jamming.

[0044] In an embodiment, the signal received by the antenna 112 includes a first signal corresponding to a first frequency band and a second signal corresponding to a second frequency band. In this embodiment, the receiver manager assigns a first correlator channel of the correlator 166 to the first frequency band signal based on the PRN code of the first frequency band signal and assigns a second correlator channel of the correlator 166 to the second frequency band signal based on the PRN code of the second frequency band signal.

[0045] Receiver 160 may include other components such as an analog-to-digital converter (ADC), but descriptions of these components are omitted for brevity.

[0046] By using a single antenna 110 with multiple feed points supporting different polarizations, time-division multiplexing multiple polarized signals using a switch, and then processing the time-division multiplexed signals in the digital domain at the receiver, there is no need to use an antenna array. As a result, the size and cost associated with the antenna are reduced. Assigning complex weights, including amplitude weights and phase weights, to each of the multiple polarized signals allows a single antenna to be used to perform zero steering for satellite signals during correlation. By using multiple correlator channels of the correlator 166 for multiple satellite signals, zero steering is performed individually for each satellite signal, thereby allowing for increased accuracy in mitigating multipath interference, jamming, and spoofing. In addition, superimposing multiple signals carried by the antenna cable 140 (e.g., switching signals and DC bias signals) avoids the need for multiple antenna cables, which results in reduced cost and size.

[0047] Figure 2 is a flow chart illustrating an exemplary method 200 for processing a signal consistent with some embodiments of the present disclosure. The method may be performed by, for example, Figure 1 The device 100 is executed by the device. Figure 2 , the method 200 includes a step S210 of generating a switching signal. For example, the switching signal may be generated by, for example, Figure 1 The switching signal may be generated by a receiver of the receiver 160. The switching signal may be synchronized by mixing with a local oscillator signal provided by a local oscillator. The generated switching signal may be transmitted to an antenna assembly such as the antenna assembly 110 via the antenna cable 140.

[0048] The method 200 includes a step S220 of controlling a switch in the antenna assembly based on the switching signal. For example, the switching signal sent to the antenna assembly 110 is used to control the switch 124 of the switching circuit 122 of the antenna assembly 110.

[0049] Method 200 includes step S230 of time-division multiplexing multiple polarized signals using a switch. For example, under the control of a switching signal, switch 124 of switching circuit 122 of antenna assembly 110 periodically switches between multiple feed points of antenna 112 and selects a signal at a time point, thereby time-division multiplexing the multiple polarized signals. The time-division multiplexed signal is then transmitted to receiver 160 for processing in the digital domain at the receiver (e.g., by control engine 162 and steering engine 164), for example, through software-based signal processing. In an embodiment, the time-division multiplexed signal may be amplified and filtered at antenna assembly 110 before being transmitted to receiver 160.

[0050] Method 200 includes step S240 of determining a desired amplitude and a desired phase for each of the plurality of polarized signals in the time-division multiplexed signal. For example, the desired amplitude and the desired phase for each of the plurality of polarized signals in the time-division multiplexed signal may be determined by a control engine (e.g., control engine 162 of receiver 160) or by a steering engine (e.g., steering engine 164 of receiver 160). The desired amplitude and the desired phase for each of the plurality of polarized signals may be determined based on at least one of the following: a desired null direction, a desired beam direction, a direction of an interference source, or a direction of dominant multipath interference. The desired amplitude and the desired phase for each of the plurality of polarized signals may be determined using on-the-fly optimization or a model.

[0051] The method 200 includes a step S250 of assigning a complex weight to each of the plurality of polarization signals in the time division multiplexed signal. The complex weight may include a weight for the amplitude and a weight for the phase of each of the plurality of polarization signals. In an embodiment, the complex weight for each of the plurality of polarization signals may be assigned by a steering engine (e.g., Figure 1 The steering engine 164 of the receiver 160 may be assigned by the steering engine 164. For example, the steering engine may obtain the complex weights corresponding to the desired null direction from a lookup table included in the receiver 160. In another embodiment, the complex weights for each of the multiple polarization signals may be assigned by the control engine. For example, the control engine may perform a sequential optimization process to instantly determine the complex weights to be used for a given correlator channel.

[0052] Method 200 includes step S260 of correlating a plurality of time-division multiplexed polarization signals. This correlation may be performed by a correlator comprising a plurality of correlator channels (e.g., correlator 166 of receiver 160). In each correlator channel, a mixer mixes the input time-division multiplexed signal with a local oscillator signal generated by an NCO of the correlator channel. In each correlator channel, a unique PRN code corresponding to a signal transmitted from a satellite may be generated, and a complex weight may be applied to each of the plurality of polarization signals.

[0053] Figure 3 is a block diagram of an exemplary apparatus 300 consistent with some embodiments of the present disclosure. Figure 3 The apparatus 300 may take any form, including but not limited to a laptop computer, a global positioning system (GPS), a wireless terminal including a mobile phone, a wireless handheld device, or a wireless personal device, or any other form. The apparatus 300 includes a receiver 302, an antenna 312 coupled to the receiver 302, a processor 304, a memory 306, a local clock 308, and an input / output device 310.

[0054] Receiver 302, coupled to antenna 312, is configured to receive signals from one or more signal sources. In some embodiments, receiver 302 may be part of a transceiver modem that includes a transmitter configured to transmit data to an external device. Local clock 308 provides the local time to which device 300 is set.

[0055] In an embodiment, similar to Figure 1 Receiver 160, receiver 302 may implement a correlator including multiple correlator channels (e.g., Figure 1 Each of the plurality of correlator channels may be assigned to a different one of the plurality of signals transmitted from a corresponding one of the plurality of satellites. In each correlator channel, a mixer may be used to mix the input time-division multiplexed signal with a local oscillator signal generated by the NCO of the correlator channel.

[0056] In an embodiment, similar to Figure 1 Receiver 160, receiver 302 may include a control engine (e.g., Figure 1Receiver 302 may also include a control engine 162 (e.g., steering engine 164) that determines a desired phase and a desired amplitude for each of the multiple polarized signals. Receiver 302 may also include a steering engine (e.g., steering engine 164) that assigns complex weights to each of the multiple polarized signals. A PRN code generator may generate a PRN code in each correlator channel. The control engine and / or steering engine may be implemented as a program stored in a computer-readable storage unit of the receiver. Receiver 302 may include a built-in processor (not shown) configured to execute the program and perform the functions of the control engine and steering engine.

[0057] The receiver 302 may include a switching signal generator (eg, Figure 1 The switching signal generator 130 of FIG. 1 may be controlled by the steering engine. The receiver 302 may include other components such as a bias signal generator. For the sake of simplicity, the description of these components is omitted here.

[0058] Processor 304 may include one or more dedicated processing units, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or various other types of processors or processing units. In an embodiment, the processor provided within receiver 302 may be a front-end processor that performs signal processing within receiver 302, and processor 304 may be a back-end processor that receives signal processing results from receiver 302 and provides feedback to receiver 302. In this embodiment, processor 304 may also perform a portion of the digital domain signal processing of receiver 302. Processor 304 may also perform additional calculations (e.g., for determining the receiver's location). Processor 304 may also be configured to control the performance of input / output device 310, clock 308, and memory 306. In another embodiment, receiver 302 does not have a built-in processor, and processor 304 performs all functions of a built-in processor. In another embodiment, device 300 does not have processor 304, and a built-in processor of receiver 302 performs all functions of processor 304.

[0059] Memory 306 can be any type of computer-readable storage medium, including volatile or non-volatile memory devices, or a combination thereof. Memory 306 can store information related to the identity of device 300 and GNSS signals received by receiver 302. Memory 306 can also store post-processed signals (e.g., correlation signals). Memory 306 can also store computer-readable program instructions and mathematical models used in signal processing in receiver 302 and calculations performed in processor 304. Memory 306 can also store computer-readable program instructions for use by processor 304 to operate device 300.

[0060] Input / output device 310 can be used to communicate signal processing results to a user or another device. Input / output device 310 may include a user interface, including a display and input devices for sending user commands to processor 304. The display can be configured to display the signal reception status at device 300, data stored in memory 306, signal processing status, and signal processing results. For example, the display can show the results of null steering, beam steering, tracking, and positioning. The display may include, but is not limited to, a cathode ray tube (CRT), a liquid crystal display (LCD), a light emitting diode (LED), a gas plasma display, a touch screen, or other image projection device for displaying information to a user. The input device can be any type of computer hardware device for receiving data and control signals from a user. The input device may include, but is not limited to, a keyboard, a mouse, a scanner, a digital camera, a joystick, a trackball, cursor direction keys, a touch screen monitor, or an audio / video controller. Input / output device 310 may also include a machine interface, such as an electrical bus connection or a wireless communication link.

[0061] The computer-readable storage medium of the present disclosure may be a tangible device that can store instructions for execution by an instruction execution device. The computer-readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of computer-readable storage media includes the following: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device (e.g., a punch card or a raised structure in a groove having instructions recorded therein), and any suitable combination of the foregoing.

[0062] The computer readable program instructions of the present disclosure can be source code or object code written in any combination of assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data or any combination of one or more programming languages, including object-oriented programming languages and traditional process programming languages. The computer readable program instructions can be executed completely on a computing device as an independent software package, or partially on a first computing device and partially on a second computing device away from the first computing device. In the latter case, the second remote computing device can be connected to the first computing device through any type of network, including a local area network (LAN) or a wide area network (WAN).

[0063] The flowcharts and block diagrams in the accompanying drawings illustrate examples of the architecture, functionality, and operation of possible implementations of systems, methods, and apparatus according to various embodiments. It should be noted that in some alternative implementations, the functions indicated in the blocks may not occur in the order indicated in the figures. For example, depending on the functionality involved, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in the reverse order.

[0064] It will be understood that the described embodiments are not mutually exclusive and elements, components, materials or steps described in conjunction with one example embodiment may be combined with or removed from other embodiments in a suitable manner to achieve the desired design objectives.

[0065] Reference herein to "some embodiments" or "some exemplary embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment. The appearance of the phrases "one embodiment," "some embodiments," or "another embodiment" in various places throughout this disclosure does not necessarily refer to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

[0066] It should be understood that the steps of the example methods described herein do not necessarily need to be performed in the order described, and the order of the steps of these methods should be understood to be merely an example. For example, depending on the functionality involved, two blocks shown in succession may in fact be performed substantially simultaneously, or the blocks may sometimes be performed in the reverse order. Similarly, these methods may include additional steps, and certain steps may be omitted or combined in methods consistent with various embodiments.

[0067] As used in this disclosure, the word "exemplary" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Instead, the word is used to present concepts in a concrete manner.

[0068] As used in this disclosure, unless specifically stated otherwise, the term "or" encompasses all possible combinations except those that are not feasible. For example, if a database is said to include either A or B, then unless specifically stated otherwise or not feasible, the database may include A, or B, or A and B. As a second example, if a database is said to include A, B, or C, then unless specifically stated otherwise or not feasible, the database may include A, or B, or C, or A and B, or A and C, or B and C, or A, B, and C.

[0069] In addition, as used in this disclosure and the appended claims, the articles "one or more" should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form.

[0070] Unless expressly stated otherwise, each numerical value and range should be interpreted as approximate as if the value or range were preceded by the word "about" or "approximately."

[0071] Even though elements in the accompanying method claims (if any) are recited in a specific order, those elements are not necessarily intended to be limited to implementation in that specific order unless the claim recitation otherwise implies a specific order of implementation of some or all of those elements.

[0072] It will be understood that certain features of the present disclosure that are described for clarity in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features of the specification that are described for clarity in the context of a single embodiment may also be provided individually or in any suitable subcombination or as appropriate in any other described embodiment of the specification. Unless so indicated, certain features described in the context of various embodiments are not essential features of those embodiments.

[0073] It will also be understood that various modifications, substitutions and changes in the details, materials and arrangements of parts described and shown to illustrate the nature of the described embodiments may be made by those skilled in the art without departing from the scope. Accordingly, the appended claims encompass all such substitutions, modifications and changes that fall within the terms of the claims.

Claims

1. An antenna assembly, comprising: an antenna configured to receive a signal and generate, at a plurality of feed points of the antenna, a corresponding plurality of polarized signals having respective polarization directions different from one another using the received signal; as well as A switching circuit is configured to time-division multiplex the polarization signals and periodically switch between the multiple feeding points of the antenna to select a corresponding one of the multiple polarization signals at a time point based on a switching signal.

2. The antenna assembly according to claim 1, wherein: The plurality of feeding points includes at least three feeding points.

3. A communication device, comprising the antenna assembly according to claim 1, further comprising: a receiver coupled to receive the selected polarization signal and configured to: processing the selected polarization signal; as well as The switching signal is generated based on the processing.

4. The communication device according to claim 3, further comprising: a cable coupling the antenna assembly and the receiver and configured to: transmitting the selected polarization signal from the antenna assembly to the receiver; as well as The generated switching signal is sent from the receiver to the antenna assembly.

5. The communication device according to claim 3, wherein: The switching signal controls the switch in the switching circuit to switch between the plurality of feeding points, and The switching circuit is configured to time-division multiplex the plurality of polarization signals based on the switching signal and generate a time-division multiplexed signal. The communication device according to claim 5 , wherein: The receiver further comprises: a control engine configured to determine a desired amplitude and a desired phase for each of the plurality of polarized signals; and A steering engine is configured to assign a complex weight to each of the plurality of polarization signals based on the desired amplitude and the desired phase of each of the plurality of polarization signals, wherein the complex weight includes an amplitude weight and a phase weight.

7. The communication device according to claim 6, wherein: The signal received by the antenna is a spread spectrum signal, and The control engine includes a control loop configured to determine the desired amplitude and the desired phase for each of the plurality of polarized signals based on at least one of: Desired zero direction; Desired beam direction; The direction of the interference source; or The direction of dominant multipath interference. The communication device according to claim 6 , wherein: The receiver further comprises: A correlator is configured to correlate the time division multiplexed signals generated by the switching circuit.

9. The communication device according to claim 8, wherein: The correlator includes a correlator channel including a numerically controlled oscillator and a pseudo-random noise (PRN) code generator.

10. The communication device according to claim 9, wherein: The PRN code generator is configured to generate a PRN code corresponding to the signal received by the antenna. The communication device according to claim 10 , wherein: In the correlator channel, the complex weight assigned to each of the plurality of polarization signals is applied to a correlated time-division multiplexed signal by: shifting the phase of the correlated signal in the numerically controlled oscillator based on the phase weight in the complex weight; and The amplitude of the correlated signal is adjusted based on the amplitude weight in the complex weight.

12. The communication device according to claim 3, wherein: The receiver further includes a switching signal generator configured to generate a pulse signal or an AC signal as the switching signal.

13. The communication device according to claim 6, wherein: The control engine is configured to determine the desired amplitude and the desired phase for each of the plurality of polarized signals using an on-the-fly optimization or model.

14. The communication device according to claim 12, wherein: The antenna assembly further includes a switching signal detector configured to detect the switching signal generated by the switching signal generator.

15. The communication device according to claim 3, wherein: The antenna assembly further includes: a low noise amplifier configured to amplify the selected polarization signal; a low-pass filter configured to filter the switching signal; and a bandpass filter configured to receive and filter the amplified signal, and the receiver further comprising: A bias circuit is configured to provide a direct current (DC) bias to the low noise amplifier of the antenna assembly.

16. The communication device according to claim 8, wherein: The signal received by the antenna includes a plurality of signals respectively transmitted from a plurality of different satellites, and The correlator includes a plurality of correlator channels, each of the plurality of correlator channels is assigned to a different one of the plurality of signals, and each of the plurality of correlator channels includes a numerically controlled oscillator and a PRN code generator.

17. The communication device according to claim 16, wherein: The plurality of signals respectively correspond to a plurality of PRN codes, and the receiver is configured to assign each of the plurality of PRN codes to a corresponding one of the plurality of correlator channels.

18. The communication device according to claim 8, wherein: The signal received by the antenna includes a first signal corresponding to a first frequency band and a second signal corresponding to a second frequency band, and The correlator includes a first correlator channel corresponding to the first frequency band based on the PRN code of the first frequency band and a second correlator channel corresponding to the second frequency band based on the PRN code of the second frequency band.

19. A method for operating a device, wherein: The apparatus includes an antenna configured to receive a signal and generate a plurality of polarized signals having respective polarization directions different from each other, the method comprising the steps of: generating a switching signal; controlling a switch in the antenna based on the generated switching signal; time-division multiplexing the plurality of polarization signals using the switch; determining a desired amplitude and a desired phase for each of the plurality of polarized signals; Assigning a complex weight to each of the plurality of polarization signals, wherein the complex weight includes a weight of amplitude and a weight of phase; and The time-division-multiplexed plurality of polarization signals are correlated.

20. A non-transitory computer-readable medium storing instructions, the instructions, when executed by a processor, performing a method for controlling a device, the method comprising the steps of: generating a switching signal by the device; sending the generated switching signal to the antenna assembly so that the switching signal drives a switch in the antenna assembly; receiving, from the antenna assembly, a time division multiplexed signal generated by periodically selecting a polarization signal from a plurality of polarization signals based on the switching signal; determining, by the device, a desired amplitude and a desired phase for each of the plurality of polarized signals; Assigning, by the apparatus, a complex weight to each of the plurality of polarization signals, wherein the complex weight includes an amplitude weight and a phase weight; as well as The time-division-multiplexed plurality of polarization signals are correlated by the apparatus.

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