Method and apparatus for improving co-channel operation of independent wireless systems

Abstract

A method and apparatus for improving co-channel operation of simultaneously operating independent wireless systems. The method and apparatus receive at least one signal, perform motion compensation correlation on the at least one signal, and determine the direction of arrival of the at least one signal. A response to the direction of arrival is performed to improve co-channel operation of the wireless system.

Description

Background

[0001] [Technical Field]

[0001] Embodiments of the present invention generally relate to wireless communication, and more particularly, to methods and apparatuses for providing co-channel operation of independent wireless systems.

[0002] [Description of Related Art]

[0002] The radio frequency band has become more congested with competing radio signals. For example, using various modulation techniques such as code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), quadrature amplitude modulation (QAM), time division multiplexing (TDM), or combinations thereof, has enabled transmitters and receivers to operate in the same band, i.e., in co-channel operation. However, signals using a very low signal-to-noise ratio or signals that do not use an advanced modulation scheme may be significantly affected by co-channel transmission.

[0003]

[0003] In recent situations, it has been found that 5G (fifth generation mobile communication system) cellular signal transmitters interfere with the altimeters of aircraft operating in the same band. One of the frequency bands in which the 5G system operates is 3.7 - 3.98 GHz, but certain aircraft altimeters used at altitudes below 2500 feet use a frequency band of 4.2 - 4.4 GHz. This type of altimeter is used for low-visibility approaches to airports, but the aircraft uses an autopilot system. The proximity of the 5G operating band to the altimeter band has resulted in incorrect altitude measurements. Interference with the accuracy of aircraft altimeters can be harmful to the operational safety of aircraft.

[0004]

[0004] Therefore, there is a need for methods and apparatuses for improving co-channel operation of independent wireless systems. Summary

[0005]

[0005] According to an aspect of the present invention, there is provided a method for improving co-channel operation between a plurality of wireless systems using a signal processing system, the method comprising: In a receiver of a signal processing system, receiving a first signal from a first remote source and a second signal from a second remote source, wherein the first signal and the second signal have the same or similar frequencies that cause the first signal to interfere with the reception of the second signal; Selecting one of the first signal and the second signal; Correlating at least one local signal with the selected signal to generate at least one correlation result; Determining the movement of the receiver's antenna; Generating a plurality of phasers each including a signal phase, wherein each phaser represents an estimation of the direction of arrival for the selected signal; Compensating the phase of at least one of the at least one local signal, the selected signal, or the at least one correlation result based on the plurality of phasers and the corresponding plurality of estimated directions of arrival to generate a plurality of phase-compensated correlation results; Determining phasers in the plurality of phasers for generating optimized phase-compensated correlation results; Identifying the direction of arrival for the selected signal using the determined phasers; Determining one or more actions for improving the reception of the second signal at the receiver from the direction of arrival of the selected signal; Performing the one or more actions; Including.

[0006]

[0006] In this way, interference between a first signal (which can correspond to an unwanted signal) and a second signal (which can correspond to a signal intended to be received by a signal processing system) in a receiver can be reduced. One or more actions utilize the determined direction of arrival to adjust the behavior of multiple wireless systems, namely, a first remote source, a second remote source, and / or the signal processing system, to improve the reception of the second signal in the receiver. This reduces the interference of these wireless systems operating at similar frequencies, or in other words, improves the operation of the wireless systems on the same channel.

[0007]

[0007] One or more actions can be any suitable action for minimizing interference. In one example, the action can be to switch the first or second remote source to a different frequency, or to request that the first or second remote source be switched. The determined direction of arrival can be used to identify the first or second remote source in order to make such a request.

[0008]

[0008] The second remote source can be the original radiation source, i.e., a transmitter external to the signal processing system. Alternatively, the second remote source can be the reflection point of a signal emitted by the transmitter of the signal processing system. In one example, the signal processing system is located at the same location as a radar system, and the second signal corresponds to a reflected radar signal used to determine the distance to an object. The first signal can also be a direct line-of-sight signal or a reflected signal. However, in any case, the first signal and the second signal originate from different transmitters.

[0009]

[0009] The first and second signals may have similar frequencies in the receiver that are sufficient to degrade the quality of reception of the second signal relative to the reception of the first signal. In one example, the first and second signals may be in adjacent frequency bands, or within the same frequency band. The first and second signals are preferably radio signals, and the first and second remote sources are preferably radio sources.

[0010]

[0010] The first and second signals may also include a deterministic code, such as a Gold code, or other GNSS satellite code, used in the positioning calculation.

[0011]

[0011] One or more actions may be performed based on the direction of arrival calculated for only one of the first and second signals. Alternatively, the direction of arrival can be determined in the same way for both signals, or in other words, the following further steps, namely, correlating at least one local signal with the remaining signal to generate at least one correlation result, and determining the movement of the antenna, and generating a plurality of phasors each having a signal phase, each phasor representing an estimate of the direction of arrival with respect to the remaining signal, compensating the phase of at least one of the at least one local signal, the remaining signal, or the at least one correlation result based on the plurality of phasors and the corresponding plurality of direction-of-arrival estimates to generate a plurality of phase-compensated correlation results, determining a phasor among the plurality of phasors that generates an optimized phase-compensated correlation result, identifying the direction of arrival with respect to the remaining signal using the determined phasor can be determined by performing. In this case, one or more actions can be determined and performed based on the direction of arrival calculated for both the first and second signals.

[0012]

[0012] Each phaser can numerically represent a phase offset where there is no relative motion between the antenna and the signal, such that a signal coming from a specific direction is detected due to the movement of the antenna. In this sense, each phaser represents a "hypothesis" of the direction of arrival for the signal, and can be referred to as a "hypothesis" as shown anywhere in this specification.

[0013]

[0013] The signal phase at each phaser represents the direction of arrival for the selected signal. The signal phase can also include a phase component corresponding to the movement of the antenna. The step of generating a plurality of phasers can include the step of generating a set of phase hypotheses (or "phasers") regarding the movement of the antenna, and a set of phase hypotheses (or "phasers") regarding the direction of arrival for each received signal. Alternatively, two sets of hypotheses can be combined into a single set of hypotheses that are tested simultaneously to determine the direction of arrival.

[0014]

[0014] One or more actions preferably include changing the transmission pattern of the first signal and / or the second signal, and / or changing the sensitivity pattern of the antenna, based on the identified direction of arrival, to improve the reception of the second signal at the receiver. In this way, the gain, or intensity, of the first signal can be reduced, or alternatively, the gain of the second signal can be increased by aligning the low or high sensitivity regions of the antenna with the direction of arrival of the first and / or second signals. This minimizes the harmful interference effect of receiving the first signal and the second signal simultaneously.

[0015]

[0015] The transmission pattern can be a spatial antenna pattern, also known as the "radiation pattern" of the first or second remote source. The pattern can be changed to different three-dimensional profiles or rotated in different orientations so that the main transmission lobe points in the direction of the antenna of the signal processing system or in a direction away from the antenna. In a specific example, the antenna pattern can also be changed from a typical fan-shaped pattern to a "knife-edge" pattern that is more strongly weighted in a specific direction. The transmission pattern can also be a temporal pattern, and the transmission can be temporarily suppressed or "disabled" to prevent interference between the first signal and the second signal. In one example, the transmission of the first signal can be suppressed for a predetermined period or while the antenna and the first remote source are within a threshold distance. Similarly, the sensitivity pattern of the antenna can be changed spatially by redirecting or changing its radiation pattern again. Alternatively, the sensitivity pattern can be changed temporally by temporarily ignoring (or "disabling") the signal received by the antenna.

[0016]

[0016] Rotating or changing the radiation pattern of the antenna can be implemented mechanically by physically moving the antenna or digitally using, for example, an electronic beam steering unit that drives a phased array antenna to change the antenna pattern, as is known to those skilled in the art. Motion compensation can be used to artificially change or redirect the pattern of the antenna. For example, motion compensation can be used to adjust receiver parameters such as frequency and frequency rate to enhance the reception of desirable signals arriving at the antenna from a specific direction or to suppress the reception of undesirable signals arriving at the antenna from different directions.

[0017]

[0017] In one embodiment, the direction of arrival can be used to identify the source of the first signal. For example, the first signal can be radiated by a 5G radio tower at a known location, in which case the determined direction of arrival of the first signal can be compared to the known location. A command to temporarily block the transmission of the first signal can be sent to the identified source. Alternatively, the direction of arrival can be used to determine that the source cannot be identified, in which case the sensitivity pattern of the antenna or receiver can be changed to avoid interference.

[0018]

[0018] One or more of the determined actions preferably include performing beam steering of the antenna. In this way, the radiation pattern of the antenna can be aligned with the calculated direction of arrival and position of the first signal or the second signal to improve the reception of the second signal or the "gain" at the receiver.

[0019]

[0019] When selecting one of the first signal and the second signal includes selecting the second signal, performing beam steering of the antenna preferably includes steering the main sensitivity lobe of the antenna in the determined direction of arrival of the second signal. In this way, since the most sensitive region or lobe of the antenna is oriented to point in the direction of arrival of the (desired) second signal, the intensity or gain of the received second signal can be increased.

[0020]

[0020] When selecting one of the first signal and the second signal includes selecting the first signal, performing beam steering of the antenna preferably includes steering the sensitivity null of the antenna in the determined direction of arrival of the first signal. In this way, since the antenna is oriented such that at least one of the sensitivity regions of the antenna is aligned with the direction of arrival of the (undesired) first signal, the intensity or gain of the received first signal can be reduced. This indirectly improves the reception of the second signal or the signal-to-noise ratio because the first signal is detected at a low amplitude.

[0021]

[0021] In an embodiment in which the arrival directions of both the first signal and the second signal are calculated, the beam steering of the antenna or the adjustment of the radiation pattern can be performed so as to simultaneously align the arrival direction of the first signal with the sensitivity null of the antenna and align the arrival direction of the second signal with the main lobe. Doing so can further reduce the interference between the first signal and the second signal.

[0022]

[0022] The radiation pattern of the antenna can be steered or changed to continuously track the change in the arrival direction of the second remote source, taking into account the movement between the antenna and the second remote source. This can be achieved by continuously recalculating the arrival direction of the second signal. The recalculation of the arrival direction can be determined based on the previous calculation, for example, based on the incremental change with respect to the previous phase in a plurality of phasers that generate an optimized phase compensation correlation result. This takes advantage of the fact that any change in the relative positions of the antenna and the second remote source is likely to be done gradually to more efficiently recalculate the arrival direction. Similarly, the arrival direction of the first signal can be calculated continuously in the same way, for example, by repeatedly rotating or changing the radiation pattern of the antenna to align the arrival direction of the first signal with the sensitivity null.

[0023]

[0023] One or more actions preferably include sending a third signal to the first remote source or the second remote source to instruct the first remote source or the second remote source to perform a correction action to improve the reception of the second signal at the receiver. In this way, the signal processing system can communicate with the remote source to handle the interference at the receiver. The correction action can be any suitable means for reducing the interference at the receiver, such as switching to another frequency or adjusting the transmission pattern of the first or second signal.

[0024]

[0024] When one or more actions include sending a third signal to a first remote source, the corrective action preferably includes performing beam steering of the antenna of the first remote source away from the receiver or temporarily disabling the transmission of the first signal. In this way, the signal processing system can communicate with the first remote source to address interference at the receiver. Using the third signal, the angular position of the antenna of the signal processing system is notified to the first remote source so that the first remote source can steer its antenna beam away from the antenna of the signal processing system.

[0025]

[0025] The signal processing system is preferably installed on an aircraft. In this way, the method can be used to protect the aircraft from potentially dangerous interference that could impair various operations of the aircraft and pose a risk to the safety of those on board.

[0026]

[0026] The second signal is preferably a landing signal configured to assist the landing operation of the aircraft. In one example, the first remote source can be a 5G cellular network having an antenna mast near the airport. The receiver can be part of an aircraft altimeter radar that may provide inaccurate altitude readings when the 5G system is transmitting in the vicinity. In this case, the second signal can be a signal emitted by the transmitter of the altimeter reflected from the ground towards the aircraft. Embodiments of the present invention can be implemented on an aircraft to determine the direction of arrival of 5G signals from nearby masts. Embodiments can control the receiving antenna pattern of the altimeter to reduce the reception of signals in the direction of the 5G mast or disable the operation of the altimeter to avoid incorrect altitude measurements that could lead to a risk of collision with the aircraft.

[0027]

[0027] The first signal is preferably a 5G signal. In this way, interference caused by 5G signals, which can be a common type of signal causing interference, can be reduced.

[0028]

[0028] The first signal and the second signal preferably have a frequency difference of about 1 GHz or less. In one example, the first signal can have a frequency of about 3.7 GHz to 3.98 GHz, and the second signal can have a frequency of about 4.2 to 4.4 GHz.

[0029]

[0029] Improving the reception of the second signal in the receiver preferably includes improving the signal-to-noise ratio of the second signal in the receiver. Improving the reception of the second signal in the receiver may also be referred to as improving the gain or intensity of the second signal.

[0030]

[0030] The present invention is also said to provide a method for reducing wireless interference between two wireless signals in a receiver.

[0031]

[0031] According to a further aspect of the present invention, there is provided a signal processing system for improving the operation of the same channel between a plurality of wireless systems, the system comprising: A receiver comprising an antenna configured to receive a first signal from a first remote source and a second signal from a second remote source, the first signal and the second signal having the same or similar frequencies that interfere with the reception of the second signal in the receiver, the receiver; A controller, Selecting one of the first signal and the second signal, Correlating at least one local signal with the selected signal to generate at least one correlation result, Determining the movement of the antenna, Generating a plurality of phasers each having a signal phase, each phaser representing an estimate of the direction of arrival with respect to the selected signal, generating, Compensating the phase of at least one of the plurality of phasers, the selected signal, or at least one of the at least one correlation results based on the plurality of phasers and the corresponding plurality of direction-of-arrival estimates to generate a plurality of phase-compensated correlation results. Determining a phaser among a plurality of phasers that generate an optimized phase compensation correlation result Identifying the direction of arrival for a selected signal using the determined phaser Determining one or more actions for improving reception of a second signal at a receiver from the direction of arrival of the selected signal, and Performing the one or more actions A controller configured to perform the above Comprising

[0032]

[0032] A non-transitory computer-readable medium that, when executed by a computer, causes the computer to perform the following steps, namely Selecting one of a first signal received at a receiver from a first remote source and a second signal received at the receiver from a second remote source, wherein the first signal and the second signal have the same or similar frequencies such that the first signal can interfere with reception of the second signal at the receiver Correlating at least one local signal with the selected signal to generate at least one correlation result Determining movement of an antenna of the receiver Generating a plurality of phasers each having a signal phase, each phaser representing an estimate of the direction of arrival for the selected signal Compensating the phase of at least one of the at least one local signal, the selected signal, or the at least one correlation result based on the plurality of phasers and the corresponding plurality of estimated directions of arrival to generate a plurality of phase compensation correlation results Determining a phaser among a plurality of phasers that generate an optimized phase compensation correlation result Identifying the direction of arrival for the selected signal using the determined phaser Determining one or more actions for improving reception of a second signal at a receiver from the direction of arrival of the selected signal performing one or more actions; A non - transitory computer - readable medium storing executable instructions for causing steps including the above to be performed.

[0033]

[0033] According to a further aspect of the present invention, a method for improving co - channel operation between a plurality of wireless systems using a signal processing system is provided. The method includes: receiving at least one signal from at least one remote source; correlating at least one local signal with at least one received signal to generate at least one correlation result; determining the movement of an antenna of the signal processing system; generating a plurality of phasers, each phaser representing a hypothesis including a signal phase representing an estimate of the direction of arrival for at least one received signal; compensating the phase of at least one of the local signal, at least one received signal, or at least one correlation result based on a plurality of hypotheses regarding the determined movement and direction of arrival to generate a plurality of phase - compensated correlation results; determining a hypothesis among a plurality of hypotheses for optimizing at least one phase - compensated correlation result; identifying the direction of arrival for at least one received signal using the determined hypothesis; determining a response applied to at least one received signal from the direction of arrival of each at least one received signal to improve co - channel operation.

[0034]

[0034] According to a further aspect of the present invention, a method for improving co - channel operation between two wireless systems including a first wireless system transceiver having an antenna and a transceiver controller for controlling an antenna pattern for the antenna is provided. The method includes: Receiving at least one signal from a remote source forming part of a second wireless system, wherein the at least one signal is an unwanted signal that interferes with the operation of a first wireless system transceiver; Correlating at least one local signal with the at least one received signal to generate at least one correlation result; Determining the movement of an antenna of the first wireless system transceiver; Generating a plurality of phasers, each phaser representing a hypothesis including a signal phase representing an estimate of the direction of arrival for the at least one received signal; Compensating at least one of the local signal, the at least one received signal, or at least one of the at least one correlation results based on a plurality of hypotheses regarding the determined movement and direction of arrival to generate a plurality of phase-compensated correlation results; Determining a hypothesis among a plurality of hypotheses that optimizes at least one of the phase-compensated correlation results; Identifying the direction of arrival for the at least one received signal using the determined hypothesis; Adjusting the antenna pattern using a transceiver controller to reduce signal reception of the unwanted signal; comprising.

[0035] According to a further aspect of the present invention, there is provided an apparatus for performing signal correlation within a signal processing system, the apparatus comprising at least one processor and at least one non-transitory computer-readable medium for storing instructions, the instructions, when executed by the at least one processor, causing the apparatus to perform the following steps, namely: Receiving at least one signal from at least one remote source; Correlating at least one local signal with the at least one received signal to generate at least one correlation result; Determining the movement of an antenna of the signal processing system; Generating a plurality of phasers, each phaser representing a hypothesis comprising a signal phase representing an estimate of the direction of arrival for at least one received signal; Compensating at least one phase of a local signal, at least one received signal, or at least one correlation result based on a plurality of hypotheses regarding the determined movement and direction of arrival to generate a plurality of phase-compensated correlation results; Determining a hypothesis among a plurality of hypotheses that optimizes at least one of the phase-compensated correlation results; and identifying a direction of arrival for at least one received signal using the determined hypothesis; Determining a response applied to at least one received signal from the direction of arrival of each at least one received signal to improve co-channel operation; Performing an operation including the above.

[0036]

[0036] These and other features and advantages of the present disclosure can be understood by reconsidering the following detailed description of the present disclosure in conjunction with the accompanying drawings, in which like reference numerals indicate like parts throughout.

Brief Description of the Drawings

[0037]

[0037] For a more detailed understanding of the features described above of the present invention, a specific description of the present invention has been made with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings only show typical embodiments of the present invention and should not be considered as limiting the scope of the present invention, and the present invention may admit other equally effective embodiments.

[0038]

Figure 1

[0038] FIG. 1 is a block diagram of a scenario in which two independent wireless systems operate simultaneously according to at least one embodiment of the present invention.

[0039]

Figure 2

[0039] FIG. 2 is a block diagram of the first wireless system transceiver of FIG. 1 according to an embodiment of the present invention.

[0040]

Figure 3

[0040] FIG. 3 is a flowchart of an operation method related to the signal processing software of FIG. 2 according to at least one embodiment of the present invention.

[0041]

Figure 4

[0041] FIG. 4 is a flowchart of an operation method of the control software of FIG. 2 according to an embodiment of the present invention. Detailed description

[0042]

[0042] Embodiments of the present invention include an apparatus and method for improving co-channel operation of simultaneously operating independent radio systems. Many of today's wireless communication systems utilize digital signals to improve communication throughput and security. Most of these systems utilize some form of deterministic digital code, such as a Gold code, to facilitate signal acquisition. Such digital codes are deterministic by the receiver and are communicated in lockstep by the transmitter to enable the communication receiver to find, acquire, and receive the transmitted signal. Using such a deterministic code in combination with accurate motion information for the receiver, embodiments of the present invention are useful for identifying the direction of arrival (DoA) of the signal transmission path between the receiver and the transmitter. Techniques for determining the DoA using the receiver's motion information are known as SUPERCORRELATION®, and are described in U.S. Patent No. 9,780,829, issued October 3, 2017, U.S. Patent No. 10,321,430, issued June 11, 2019, U.S. Patent No. 10,816,672, issued October 27, 2020, U.S. Patent Application Publication No. 2020 / 0264317, published August 20, 2020, and U.S. Patent Application Publication No. 2020 / 0319347, published October 8, 2020, all to the same applicant, which are hereby incorporated by reference in their entirety. If the DoA of desired and / or undesired signals is known, the receiver can implement responses to improve the performance of the co-channel. For example, the receiver can use this DoA to control the reception direction to perform one or more of the following: improve the reception of signals from some transmitters (desired signals), reduce the reception of signals from some transmitters (undesired signals), or send a control signal to the transmitter to enable the transmitter to take action to change the function of the equipment at the transmitter. The reception direction can be controlled, for example, using the SUPERCORRELATION® technique or using beam steering of the antenna pattern.

[0043]

[0043] For example, when two wireless systems are operating simultaneously in close proximity using the same or substantially the same channel (e.g., the same channel), a wireless receiver or transceiver equipped with an embodiment of the present invention controls the antenna pattern of the receiver to avoid receiving signals in the direction of a transmitter that may interfere with reception while an unwanted signal is being transmitted, and / or controls the antenna pattern to improve the reception of signals in the direction of the transmitter of a desired signal. In other embodiments, the first wireless system can notify the transceiver of the second wireless system to temporarily stop transmitting or receiving when the second transceiver may be subject to interference from the first wireless system or may cause interference to the first wireless system, e.g., "disable" the second wireless system at an appropriate time and for an appropriate duration.

[0044]

[0044] In a more specific example, the first wireless system can be a 5G cellular network having an antenna mast near an airport. The second wireless system can be an aircraft altimeter radar that may transmit inaccurate altitude display values when the 5G system is transmitting. Embodiments of the present invention can be located at the same location as the aircraft to determine the DoA of 5G signals from nearby masts. This embodiment can control the antenna pattern of the altimeter to reduce the reception of signals in the direction of the 5G mast or disable the operation of the altimeter. Further improvements regarding the use of the altimeter can be made by using an antenna pattern of the altimeter directed towards the ground, perpendicular to the path of the aircraft's movement, having a fan-shaped pattern. Such a pattern facilitates the use for a very short disable period when the aircraft passes the 5G mast at high speed (e.g., 250 - 300 KPH). In a further embodiment, a transceiver using an embodiment of the present invention can send a signal to the 5G transmitter, and the transmitter can adjust the antenna pattern to avoid transmitting towards the aircraft.

[0045]

[0045] A transmitter or receiver using such an embodiment of the present invention can be fabricated to operate at low transmission power, thus reducing the cost of the overall components and / or increasing the battery life. Such improvements are useful, for example, but not limited to, in mobile devices that utilize communication techniques using deterministic codes, such as WiFi, Bluetooth®, cellular phones, etc.

[0046]

[0046] FIG. 1 shows a block diagram of a scenario 100 in which two independent wireless systems 122 and 124 (for example, system 122 is represented by first wireless system transceivers 102 and 104, and system 124 is represented by a second wireless system transceiver 106) operate simultaneously according to an embodiment of the present invention. In this exemplary embodiment, the first wireless transceiver 102 (remote source) is transmitting a desired signal 108 to the mobile first wireless signal transceiver 104, and the second wireless system transceiver 106 (another remote source) is transmitting an undesired signal 110. Signals 108 and 110 are transmitted in the same frequency band or in substantially the same frequency band (i.e., the same channel), and thus, if both signals 108 and 110 are received by the mobile transceiver 104, the transceiver 104 should not be able to receive the desired signal 108. In one embodiment, the first wireless system transceiver 102 can be a fixed base station that communicates with at least one mobile device (represented by mobile transceiver 104).

[0047]

[0047] The mobile first wireless system transceiver 104 includes a transceiver controller 118 that operates in accordance with an embodiment of the present invention to respond to a received signal to improve the same-channel operation of the wireless system. As described in detail below, the transceiver controller 118 uses the SUPERCORRELATION (registered trademark) technique described in U.S. Patent No. 9,780,829, issued October 3, 2017, U.S. Patent No. 10,321,430, issued June 11, 2019, U.S. Patent No. 10,816,672, issued October 27, 2020, U.S. Patent Application Publication No. 2020 / 0264317, published August 20, 2020, and U.S. Patent Application Publication No. 2020 / 0319347, published October 8, 2020, all of which are hereby incorporated by reference in their entirety, to determine the direction of arrival (DoA) of the received signals 108, 110, or both. As the mobile transceiver 104 moves (represented by arrow 120), the transceiver controller 118 calculates movement information representing the movement of the mobile transceiver 104. The movement information is used to perform movement compensation correlation on the received signals 108 and / or 110. From the movement compensation correlation process, the transceiver controller 118 estimates the DoA of the signals 108 and / or 110.

[0048]

[0048] From the DoA of the (multiple) signals, the transceiver controller 118 can respond to improve the same-channel operation in systems 122 and 124. In one embodiment, the response can be, for example, to change the antenna pattern 112 of the transceiver 104, such as beam steering. The pattern change can steer the main lobe 114 in the direction of the DoA of the desired signal (signal 108) to enhance the reception of the desired signal 108, or create an antenna pattern null 116 at the DoA of the undesired signal 110 to suppress the reception of the undesired signal 110, or a combination of both techniques.

[0049]

[0049] In other embodiments, the SUPERCORRELATION (registered trademark) technique can be used to enhance or suppress the reception of a signal based on its DoA. This technique adjusts receiver parameters such as frequency and frequency rate to enhance the reception of desired signals arriving at the antenna from a specific direction or to suppress the reception of unwanted signals arriving at the antenna from different directions.

[0050]

[0050] In other embodiments, the response of the transceiver can be to disable the operation of the mobile transceiver during the period when the second wireless system transceiver 106 is operating or when the mobile transceiver 104 is in proximity to the second wireless system transceiver 106.

[0051]

[0051] In an exemplary scenario, the desired signal 108 can reflect an altimeter signal transmitted by the mobile transceiver 104 located on an aircraft. The response of the transceiver controller 118 can be to change the antenna pattern to reduce unwanted signals (e.g., interfering 5G signals), switch the antenna pattern to a knife-edge to make the period of interference unimportant to the mobile transceiver, and / or disable the mobile transceiver 104 during the period when interference is likely.

[0052]

[0052] In an alternative embodiment where the wireless system is not completely independent, the mobile transceiver 104 can transmit a control signal (represented by path 126) to the second wireless system transceiver 106 in response to an unwanted signal 110. The control signal 126 can cause the transceiver 106 to change its antenna pattern to steer nulls in the direction of the mobile transceiver 104 or disable the operation of its transceiver when in proximity to the first wireless system transceiver 104. Generally, the response of the transceiver 106 to the control signal 126 is to reduce the potential for interfering with the operation of the first wireless system 122.

[0053] [

[0053] ]FIG. 2 shows a block diagram of the first wireless system transceiver 104 of FIG. 1 according to an embodiment of the present invention. The first wireless system transceiver 104 includes a mobile platform 200 and an antenna 202. The mobile transceiver 104 can form part of a laptop computer, a mobile phone, a tablet computer, an Internet of Things (IoT) device, an unmanned aerial vehicle, a mobile computing system in an autonomous vehicle, or a vehicle operated by a human. Generally, embodiments of the present invention are used in any environment where a mobile transceiver is used and may be subject to interference from another wireless system operating on the same channel.

[0054] [

[0054] ]In a typical mobile transceiver, the mobile platform 200 and the antenna 202 are non-separable units (e.g., a mobile phone), and the antenna 202 moves with the mobile platform 200. The operation of the SUPERCORRELATION (registered trademark) technique operates based on the movement of the signal receiving antenna. Any description of movement or transceiver movement described herein refers to the movement of the antenna 202. In some embodiments, the antenna 202 can be separated from the mobile platform 200. In such a situation, the motion estimation used in the motion compensation correlation process is the motion of the antenna 202. In most scenarios, the movement of the mobile platform 200 is the same as the movement of the antenna 202, and thus the following description will assume that the movement of the platform 200 and the movement of the antenna 202 are the same.

[0055]

[0055] The mobile platform 200 includes a transceiver 204, a signal processing and control system 208, and a motion module 222. The transceiver 204 includes an antenna controller 206 that facilitates antenna pattern control, i.e., beam steering of the antenna pattern. The antenna controller 206 can be a mechanical antenna steering mechanism or, more likely, an electronic beam steering unit that drives a phased array antenna to change the antenna pattern, as is well known to those skilled in the art.

[0056]

[0056] The signal processing and control system 208 includes at least one processor 210, support circuitry 212, and a memory 214. The at least one processor 210 can be in any form of a processor or combination of processors including, but not limited to, a central processing unit, a microprocessor, a microcontroller, a field programmable gate array, a graphics processing unit, a digital signal processor, etc. The support circuitry 212 can include well-known circuits and devices that facilitate the functions of the (one or more) processors. The support circuitry 212 can include one or more of, or a combination of, a power supply, a clock circuit, an analog-to-digital converter, a communication circuit, a cache, and / or the like.

[0057]

[0057] Memory 214 comprises one or more forms of a non-transitory computer-readable medium including one or more of read-only memory or random access memory, or any combination thereof. The memory 214 stores software and data, including, for example, signal processing software 216, control software 218, and data 220. The signal processing software 216, when executed by one or more processors 210, performs motion compensation correlation on the received signal to estimate the DoA of the received signal. In one embodiment, the signal processing may be used only for the targeted signals, i.e., the signals from the first wireless system and the signals from the second wireless system, and thus, the processing is concentrated on a specific signal source to improve the same-channel operation of the system. In other embodiments, the signal processing can process all received signals to achieve improved signal reception in the first wireless system transceiver, considering many simultaneously operating, same-channel systems. The motion compensation correlation process will be described in detail below with respect to FIG. 3. The operations of the signal processing software 216 and the control software 218 together function as the transceiver controller 118 of FIG. 1.

[0058]

[0058] The DoA information is used by the control software 218 to perform responses to the received signals, such as adjusting the antenna pattern, disabling the transceiver, etc. The data 220 stored in the memory 214 can also include signal estimation, correlation results, motion compensation information, motion information, position information, etc.

[0059]

[0059] The motion module 222 generates an estimate of the motion relative to the transceiver 104. The motion module can comprise an inertial navigation system (INS) as well as a global navigation satellite system (GNSS) such as GPS, GLONASS, GALILEO, DEIBOU, etc. The INS can comprise, but is not limited to, one or more of a gyroscope, a magnetometer, an accelerometer, and can also typically include other devices such as an altimeter not associated with the INS system. To facilitate motion compensation correlation, the motion module 222 generates motion information (sometimes called a motion model) that includes at least the velocity of the antenna 202 in the direction of the target transceiver, i.e., in the direction of the transmission path of the desired or undesired signal. The motion information can also include an estimate of the pitch, roll, and yaw of the platform 200 / antenna 202, as well as an estimate of the direction of travel (direction of movement) of the platform 200 / antenna 202.

[0060]

[0060] FIG. 3 is a flow diagram of an operating method 300 for signal processing software 216 according to at least one embodiment of the present invention. The method 300 can be implemented in software, hardware, or a combination of both (e.g., using the signal processing and control system 208 of FIG. 2).

[0061]

[0061] The method 300 starts at 302 and proceeds to 304, where, as described with respect to FIG. 1, signals are received at the receiver from a plurality of remote sources (e.g., transmitters such as the first and second wireless system transceivers). The received signals comprise, for example, a synchronization code of a Gold code extracted from the radio frequency (RF) signal received by the antenna. The processes of downconverting the RF signal and extracting the code are well known in the art. At 306, the method 300 receives motion information from the motion module 222 of FIG. 2. The motion information includes an estimate of the motion of the mobile transceiver 104 of FIG. 1.

[0062]

[0062] At 308, method 300 generates a plurality of phaser hypotheses regarding the direction of the received signal. Signal processing correlates at least one local code (at least one local signal) with at least one code extracted from the received RF signal. When multiple received signals are being processed, multiple local signals are generated. The phaser hypotheses are used to adjust the carrier phase of the local code with sub-wavelength accuracy relative to the extracted code. Such adjustment or compensation can be performed by adjusting the phase of the local oscillator signal, the received signal, or the correlation result. At 310, for each received signal, method 300 correlates the received signal with a local signal using a set of (multiple) motion hypotheses that includes an estimation of the phase offset required to accurately correlate the received signal with the local signal. After the motion-compensated correlation is complete, the received signal is correlated with the local signal using a phaser representing a DoA hypothesis to determine the direction of arrival of the received signal. In one embodiment, for each received signal, there is a set of hypotheses (including a set of phase hypotheses related to the motion of the antenna and a set of phase hypotheses related to the direction of arrival). In another embodiment, two sets of hypotheses can be combined into a single set of hypotheses that are all tested simultaneously.

[0063]

[0063] Motion estimation is typically a hypothesis of the motion in the direction of interest, such as the direction of the transceiver that transmitted the received signal. In initialization, the direction of interest may be unknown or inaccurately estimated. As a result, an exhaustive search technique may be used to search over all directions and for all relevant signals received in all directions to identify the direction of interest. Comparing the correlation results for all directions allows Method 300 to narrow the search space in the direction of the transceiver of interest. Using an iterative process, the search space is narrowed and the DoA estimate is determined. There is a very strong correlation between the true values of these hypotheses between iterations of the code, so the initial search can be thorough, but subsequent processing evolves over time and only requires tracking of the parameters in the system. As a result, subsequent compensation is performed on a narrower search space.

[0064]

[0064] In one embodiment, if a signal from a given transceiver has been previously received, a set of hypotheses for the newly received signal includes a set of phaser hypotheses using the predicted Doppler and Doppler rate, and / or the most recent Doppler and Doppler rate used for reception of the previous signal from that transceiver. The values can be centered around the most recent value used, or further offset by prediction of a further offset based on the motion of the mobile transceiver being predicted. Each phaser represents a hypothesis that includes the phase of the signal representing an estimate of the direction of arrival for at least one received signal. At 310, Method 300 correlates each received signal with a set of hypotheses for that signal. The hypotheses are used as parameters to form a phase compensation phaser and phase compensate the correlation process with sub-wavelength accuracy. Thus, phase compensation can be applied to the received signal, a local frequency source (e.g., an oscillator), or the correlation value. The hypotheses, collectively, are N VForm a search space, where N is the number of hypotheses and V is the number of variables that need to be determined. In addition to the search for the arrival direction space and the transceiver motion compensation space, method 300 can also apply hypotheses regarding other parameters such as oscillator frequency to correct frequency and / or phase drift. Other variables can include headings to ensure that correct motion compensation is applied. The result of the correlation process is a plurality of phase compensation correlation results, that is, for each hypothesis for each received signal, there is one phase compensation correlation value.

[0065]

[0065] At 312, method 300 processes the correlation results to find the "best" or optimal result for each received signal. In one embodiment, method 300 generates an integrated correlation output as a function (e.g., sum) of the plurality of correlation values obtained from all hypotheses for a given received signal. The integrated correlation result can be a single value, or a plurality of values, representing the parameters that provide the optimal, or best, correlation output. In one embodiment, a cost function is applied to each set of correlation values obtained for each received signal to find the optimal correlation output representing the most accurate set of variables used in the hypothesis.

[0066]

[0066] At 314, method 300 determines the DoA of each received signal from the optimal correlation result for the signal. Thus, by using motion compensation correlation, the mobile transceiver can be enabled to identify the arrival direction of the received signal. Method 300 ends at 316.

[0067]

[0067] In other embodiments, instead of using the maximum correlation value, other test criteria can also be used. For example, when the hypothesis is tested, method 300 monitors the progress of the correlation and applies a cost function that indicates one or more best hypotheses when the cost function reaches a minimum (e.g., a small Hamming distance among the peaks in the correlation plot). Thus, the integrated correlation output can be an integrated correlation value or a set of values. In other embodiments, for example, in addition to the direction hypothesis, further hypotheses can be tested to ensure that the motion compensation parameters (i.e., speed and direction of travel) are correct.

[0068]

[0068] FIG. 4 shows a flowchart of an operation method 400 of control software 218 according to the present embodiment. Method 400 starts at 402 and proceeds to 404, where method 400 receives, for example, the direction of arrival and signal information of a desired or undesired signal. At 406, method 400 determines a response considering the signal information, i.e., if the signal is desired, steers the antenna pattern to maximize the received signal strength, or if the signal is undesired, steers the antenna pattern to suppress the received signal strength. At 408, method 400 implements the response and ends at 410.

[0069]

[0069] Although multiple examples have been presented herein to illustrate various features, they are not intended to be limiting. Any one or more of the features may not be limited to the specific examples presented herein, regardless of the order, combination, or connection described. In fact, any combination of the features and / or elements described above as examples, including any variations or modifications that may not be enumerated, is intended to be achieved as well. Unless otherwise indicated, any one or more of the features can be combined in any order.

[0070] As described above, the figures are presented in this specification for illustrative purposes and are not meant to impose any structural limitations unless otherwise specified. It is contemplated that various modifications to any of the structures shown in the figures are within the scope of the invention presented in this specification. The invention is not intended to be limited to any scope of the language of the claims.

[0071]

[0071] When "coupled" or "connected" is used, unless otherwise specified, it should not be read as suggesting a limitation where coupling or connecting is restricted to physical coupling or connection, but rather should be read to include communication couplings including wireless transmission and protocols.

[0072]

[0072] Any block, step, module, or other thing described herein can represent one or more instructions that can be stored on a non - transitory computer - readable medium as software and / or can be implemented by hardware. Any such block, module, step, or other thing can be implemented in a manner automated by various software and / or hardware combinations, including the use of specialized hardware designed to achieve such purposes. As described above, any number of blocks, steps, or modules can be implemented in any order or not, including substantially simultaneously, i.e., within the tolerance of the system executing the blocks, steps, or modules.

[0073]

[0073] It should be understood that relevant features or elements are not required when conditional language including, but not limited to, "can", "could", "may", "might" is used. Thus, when conditional language is used, it should be understood that the elements and / or features are optionally present in at least some instances and, unless otherwise specified, are not necessarily conditional on anything.

[0074]

[0074] When the lists are recited alternatively or in combination (e.g., one or more of A, B, and / or C), unless otherwise indicated, any one or more combinations of any number of the recited elements are to be understood to be included (e.g., A, AB, AC, ABC, ABB, etc.). When "and / or" is used, it is to be understood that the elements may be concatenated alternatively or in combination.

[0075]

[0075] The foregoing is directed to embodiments of the invention, but other and further embodiments of the invention may be devised without departing from the basic scope thereof, which is determined by the following claims.

Claims

1. A method for improving co-channel operation between a plurality of wireless systems using a signal processing system, comprising: receiving, at a receiver of the signal processing system, a first signal from a first remote source and a second signal from a second remote source, wherein the first signal and the second signal have the same or similar frequencies that cause the first signal to interfere with the reception of the second signal; selecting one of the first signal and the second signal; correlating at least one local signal with the selected signal to generate at least one correlation result; determining the movement of an antenna of the receiver; generating a plurality of phasers, each including a signal phase, wherein each phaser represents an estimate of the direction of arrival for the selected signal; compensating at least one phase of at least one of the at least one local signal, the selected signal, or the at least one correlation result based on the plurality of phasers and corresponding estimates of the plurality of directions of arrival to generate a plurality of phase-compensated correlation results; determining phasers in the plurality of phasers that generate optimized phase-compensated correlation results; identifying the direction of arrival for the selected signal using the determined phasers; determining one or more actions for improving the reception of the second signal at the receiver based on the direction of arrival of the selected signal; and performing the one or more actions. A method comprising the above steps.

2. The method of claim 1, wherein the one or more actions include changing a transmission pattern of the first signal or the second signal and / or changing a sensitivity pattern of the antenna based on the identified direction of arrival to improve the reception of the second signal at the receiver.

3. The method of claim 1 or 2, wherein the one or more determined actions include performing beam steering of the antenna.

4. The step of selecting one of the first signal and the second signal includes the step of selecting the second signal, and performing beam steering of the antenna includes the step of steering a main sensitivity lobe of the antenna in the identified direction of arrival of the second signal. The method according to claim 3.

5. The step of selecting one of the first signal and the second signal includes the step of selecting the first signal, and performing beam steering of the antenna includes the step of steering a sensitivity null of the antenna in the identified direction of arrival of the first signal. The method according to claim 3.

6. The one or more actions include the step of sending a third signal to the first remote source or the second remote source, and instructing the first remote source or the second remote source to take a correction action to improve reception of the second signal at the receiver. The method according to any one of claims 1 to 5.

7. The one or more actions include the step of sending the third signal to the first remote source, and the correction action includes the step of performing beam steering of an antenna of the first remote source away from the receiver, or the step of temporarily disabling transmission of the first signal. The method according to claim 6.

8. The signal processing system is provided on an aircraft. The method according to any one of claims 1 to 7.

9. The second signal is a landing signal configured to assist a landing operation of the aircraft. The method according to claim 8.

10. The first signal is a fifth-generation mobile communication system signal. The method according to any one of claims 1 to 9.

11. The first signal and the second signal have a frequency difference of about 1 GHz or less. The method according to any one of claims 1 to 10.

12. The step of improving reception of the second signal at the receiver includes the step of improving a signal-to-noise ratio of the second signal at the receiver. The method according to any one of claims 1 to 11.

13. A signal processing system for improving co-channel operation between multiple wireless systems, A receiver comprising an antenna configured to receive a first signal from a first remote source and a second signal from a second remote source, wherein the first signal and the second signal have one or more same frequencies that interfere with the reception of the second signal by the receiver in the receiver, and the receiver, A controller, Selecting one of the first signal and the second signal, Correlating at least one local signal with the selected signal to generate at least one correlation result, Determining the movement of the antenna, Generating a plurality of phasers each having a signal phase, and each phaser representing an estimation of the direction of arrival for the selected signal, Compensating the phase of at least one of the at least one local signal, the selected signal, or the at least one correlation result based on the plurality of phasers and the corresponding plurality of estimated directions of arrival to generate a plurality of phase-compensated correlation results, Determining a phaser among the plurality of phasers for generating an optimized phase-compensated correlation result, Identifying the direction of arrival for the selected signal using the determined phaser, Determining one or more actions for improving the reception of the second signal in the receiver from the direction of arrival of the selected signal, and Performing the one or more actions A controller configured to perform the above, and A signal processing system comprising the above.

14. A non-transitory computer-readable medium storing instructions that, when executed by a computer, cause the computer to: Selecting one of a first signal received by a receiver from a first remote source and a second signal received by the receiver from a second remote source, wherein the first signal and the second signal have the same or similar frequencies that interfere with the reception of the second signal by the receiver in the receiver, Correlating at least one local signal with the selected signal to generate at least one correlation result, Determining the movement of the antenna of the receiver, generating a plurality of phasers each including a signal phase, each phaser representing an estimate of the direction of arrival for the selected signal; compensating at least one phase of the at least one local signal, the selected signal, or the at least one correlation result based on the plurality of phasers and corresponding estimates of a plurality of directions of arrival to generate a plurality of phase-compensated correlation results; determining phasers among the plurality of phasers to generate optimized phase-compensated correlation results; identifying the direction of arrival for the selected signal using the determined phasers; determining one or more actions for improving reception of the second signal at the receiver from the direction of arrival of the selected signal; performing the one or more actions; A computer-readable medium that causes steps including the above to be performed.

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