CN113169794B

CN113169794B - Global navigation satellite system assisted aircraft wireless communication

Info

Publication number: CN113169794B
Application number: CN201980080007.XA
Authority: CN
Inventors: 王俊; 刘斌
Original assignee: Caton Technology Shanghai Ltd
Current assignee: Caton Technology Shanghai Ltd
Priority date: 2018-12-06
Filing date: 2019-03-12
Publication date: 2022-10-11
Anticipated expiration: 2039-03-12
Also published as: CN113169794A; WO2020117301A1; US10826595B2; US20200186236A1

Abstract

The present disclosure relates to systems and methods for providing fifth generation wireless communications or future wireless communications (5G +) for aircraft and other applications by integrating Global Navigation Satellite System (GNSS) data and other features and aspects. In various embodiments, systems and methods are disclosed for one or more of: GNSS assisted doppler estimation and tracking; GNSS assisted cell acquisition, measurement and handover target cell selection; GNSS assisted timing advance estimation and tracking; GNSS assisted power control; and/or GNSS-assisted beam identification and tracking. Each providing GNSS-assisted wireless communication, when considered alone or in any combination.

Description

Global navigation satellite system assisted aircraft wireless communication

Technical Field

The present invention relates to systems and methods for providing wireless communication between a cellular ground network and a mobile sub-network (e.g., aircraft, train, balloon, drone, etc.); and more particularly to a system and method utilizing Global Navigation Satellite System (GNSS) integration to provide fifth or future generation wireless communications (5G +) between cellular terrestrial networks and mobile subnetworks.

Background

With the advent of modern data-driven lifestyles and mobile connected devices, wireless data communication has become ubiquitous. In connection with this, aircraft passengers are increasingly demanding high-speed data connections for commercial and personal applications. There is a great demand for high-speed data connections for passengers and facilities onboard an aircraft. However, there are several challenges to providing these flight communication services.

There are two possible solutions to provide flight communications.

First, the aircraft may be serviced by a base station located on a satellite network. The Ku and Ka bands of satellites are used to establish a physical link between digital services and aircraft, with wide coverage, which may be effective for intercontinental long distance flights over the ocean. However, for short and medium haul overland flights, satellite-based solutions are relatively costly; the equipment is heavy, heavy and expensive and the time delay is long in areas with heavy air traffic. Ka-band and Ku-band satellite antennas are difficult to install on aircraft over land because installation of the satellite antenna requires a significant investment in the infrastructure of the aircraft. Furthermore, the Ka-band satellite solution requires a large transmission path from the aircraft to a stationary orbit 36,000 km above earth, which is a common obstacle for any service requiring strict delays.

A second method is that the aircraft can be served by a base station of a cellular wireless network located on the ground, i.e. a ground base station. Although the concept of flight traffic using terrestrial base stations (3G NBs and 4G enbs) has been considered in 3G and 4G communications, there are some issues related to 5G and architecture implementation using 5G terrestrial base stations (gnbs). For example, to implement a reliable 5G connection on an in-flight network, doppler shift and latency issues need to be addressed.

Flight User Equipment (FUE) differs from conventional ground User Equipment (UE) in at least the following ways: (i) The speed of the aircraft is much faster than typical ground user equipment UE and therefore the doppler speed is much higher; (ii) The aircraft has a more deterministic flight path than the ground UE; (iii) The aircraft is always connected to a Global Navigation Satellite System (GNSS).

Disclosure of Invention

Technical problem

Doppler shift and related problems associated with aircraft speed and ground-based networks make in-flight 5G wireless communications difficult to implement and maintain.

Solution to the problem

This patent relates to systems and methods for providing fifth generation (5G) wireless communications for flight communications and other applications by integrating Global Navigation Satellite System (GNSS) data and other features and aspects.

Technical effects of the invention

In some embodiments, systems and methods for GNSS assisted doppler estimation and tracking are disclosed.

In another embodiment, GNSS assisted cell acquisition, measurement and handover target cell selection is disclosed.

In another embodiment, timing advance estimation and tracking in an initial access procedure and subsequent data transmission procedure for GNSS based assistance is disclosed.

In another embodiment, GNSS-based assisted power control is disclosed.

In yet another embodiment, GNSS-based assisted beam identification, beam tracking and beam management are disclosed.

One or more of these embodiments, and others, may provide systems and methods for wireless communication between a cellular terrestrial network and a mobile subnetwork.

Each of these embodiments and others as disclosed herein, when considered individually or in any combination, can provide GNSS-assisted wireless communication. This GNSS-assisted wireless communication is the first to be able to provide fifth or future (5G +) in-flight wireless communication over cellular terrestrial networks.

Drawings

The function and effect thereof will be understood by those skilled in the art from the accompanying detailed description and drawings, in which:

FIG. 1 illustrates a network architecture for providing GNSS assisted wireless communication over a cellular terrestrial network;

FIG. 2 illustrates a GNSS assisted cell acquisition in accordance with an embodiment of the present invention;

FIG. 3 illustrates GNSS assisted beam prediction and management in accordance with an embodiment of the present invention;

FIG. 4 illustrates a signaling flow for GNSS assistance in accordance with various embodiments of the present invention.

Detailed Description

In the following description, embodiments of the invention are best understood from the following detailed description and the accompanying drawings, which are to be regarded in an illustrative rather than a restrictive sense. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments, including certain variations or alternative combinations, that depart from these details and descriptions. The examples disclosed herein are intended to enable those skilled in the art to practice the invention, but should not be construed as merely limiting the spirit and scope of the claimed invention.

Turning now to the drawings, FIG. 1 illustrates a network architecture for providing GNSS assisted wireless communication over a cellular terrestrial network.

The aircraft 200 includes in-flight user equipment 210 (also referred to herein as "in-flight UE" or "FUE"), which is typically integrated with or coupled to at least one wireless access point on the aircraft. The wireless access point serves various devices or user equipment on the aircraft, such as a laptop 220a or a mobile phone 220b, through the in-flight UE.

The in-flight UE is connected to a terrestrial cellular network that includes a plurality of terrestrial base stations, such as the next generation nodebs (gNBs) 100. Each gNB located on the flight path is configured to communicate with the in-flight UEs over forward link 110a and reverse link 110 b. As the aircraft flies along the flight path, the flying UE may switch from one connected gNB to the next gNB.

As will be further described herein, the in-flight UE is configured to communicate with satellites 300 of a Global Navigation Satellite System (GNSS) to obtain navigation data, such as: the position, vector direction and velocity of the aircraft, as well as other moving objects connected to the GNSS, may be used to compensate for wireless signal parameters to provide wireless communication for the mobile sub-network.

Terrestrial user equipment (also referred to as terrestrial UEs), such as cell phones, automobiles, and other connected devices on the ground, may further be connected to the gNBs on a terrestrial network (not shown). In this regard, the gNBs of the same cellular terrestrial network are generally capable of serving both ground UEs and in-flight UEs. Ground UEs typically do not need signal parameter compensation as do mobile subnetworks, such as when ground UEs move at speeds less than 100 miles per hour (mph).

However, as mentioned above, since the moving speed of the flying UE is much higher, the doppler velocity is particularly significant, and must be considered in order to achieve an effective connection of the flying UE with the terrestrial cellular network. For example, in the 4GHz band, the aircraft is moving at 1200 kilometers per hour (km/h) with a Doppler shift of approximately 4.4KHz. However, in the 28GHz band, at the same aircraft speed, the Doppler shift is approximately 30.8KHz.

The relatively high doppler velocity can negatively impact the performance of the system. For example, the channel may vary within a symbol of OFDM, which may result in inter-carrier interference (ICI). In addition, the channel may vary from one OFDM symbol to another OFDM symbol, which may cause channel estimation loss during data demodulation. In addition, further time-domain filtering is to reduce the channel estimation error, and fast channel variation is not favorable for time-domain filtering, which will degrade the channel estimation quality. In addition, existing Tracking Reference Signal (TRS) designs for the new air interface (i.e., 5G) can only allow doppler shifts within +/-3.75KHz in frequency range 1 (e.g., below 6GHz band) and +/-15KHz in frequency range 2 (e.g., in millimeter wave band).

Therefore, in order to achieve an effective connection between the in-flight UE and the ground network, not only the influence of the doppler velocity is considered, but also the doppler shift is sufficiently compensated.

Embodiments of the present invention disclose systems and methods for providing Global Navigation Satellite System (GNSS) assisted wireless communication between a cellular terrestrial network and a mobile sub-network.

Example 1: GNSS assisted Doppler precompensation

In one embodiment, global Navigation Satellite System (GNSS) data and derivative data that may be derived from the GNSS data, collectively referred to as "navigation data," are integrated into a wireless communication system or related method to address the doppler velocity problem described above in order to compensate for doppler frequency shift.

In a first embodiment, the in-flight UE connects to a GNSS and obtains velocity data associated with the aircraft. The in-flight UE may selectively receive other aircraft-related navigation data from the GNSS, including but not limited to: altitude, direction, and other environmental data. The navigation data estimates the doppler shift associated with the aircraft UE through a software algorithm.

With respect to signals received (Rx) by the in-flight UE, the in-flight UE is configured to compensate the received signals (received signals from the gNBs) based on the estimated doppler shift ("DS-Rx") and then continue processing other portions of the received signals Rx in accordance with known signal processing methods. Due to doppler shift, the received signal on the in-flight UE can be modeled as:

y(t)＝x(t)e ^j2π(Δft) +n(t),

where Δ f is the Doppler shift and n (t) is noise.

Thus, to reduce the doppler effect, the in-flight UE may compensate the received signal to:

y(t)e ^-j2π(Δft)

with respect to the in-flight UE transmitted (Tx) signal, the in-flight UE is configured to compensate the transmitted signal according to the estimated doppler shift ("DS-Tx") and then continue processing other portions of the transmitted signal in accordance with known signal processing methods. Similar to the above, the signal transmitted from the in-flight UE can be modeled as:

y(t)＝x(t)e ^j2π(Δft) +n(t),

where Δ f is the Doppler shift and n (t) is noise.

Thus, to reduce the doppler effect, the in-flight UE may pre-compensate the transmitted signal to:

x(t)e ^-j2π(Δft)

in this regard, the gNB of the cellular terrestrial network will receive the signal transmitted by the in-flight UE, which has been Doppler shift compensated. This compensation makes the signal suitable for 5G communication, that is, within an acceptable range of 5G.

In the first embodiment described above, the gNB is unaware of the transmit and receive functions of the in-flight UE, since all doppler shift compensation algorithms are implemented on the in-flight UE. Thus, the gNB does not need to know the speed (speed of the flying UE) and the position of the aircraft, i.e. the navigation data. However, in another embodiment, the in-flight UE may transmit the speed and position of the aircraft (navigation data) to one or more gnbs of the ground network, which may compensate the signal according to the navigation data.

Thus, in a second embodiment, the ground network is configured to process the in-flight UE communication signals to compensate for doppler shift. Thus, the network side needs navigation data such as aircraft speed and position, which may be shared from the in-flight UEs or obtained from other sources, e.g. directly from the GNSS network or through a network server with the required information.

Using the aircraft speed and location data, a server of the ground network may compensate for the doppler frequency offset based on the indicated aircraft speed and location.

In a second embodiment, the signal transmitted from the gNB to the in-flight UE is already doppler pre-compensated, and therefore, the in-flight UE does not need to be compensated during reception of the signal. Similarly, the in-flight UE may be configured to transmit signals without doppler compensation, and the gNB of the ground network may adjust the signals received at the gNB based on aircraft speed and position.

In either case, in the first embodiment, the in-flight UE makes doppler shift adjustments to the communication signal; or in the second embodiment, the communication signal is adjusted by doppler shift at the network side, and the uncompensated doppler effect can be processed by other 5G signals of the ground UE, such as Tracking Reference Signal (TRS), synchronization Signal Broadcast (SSB), and the like.

Accordingly, the present application may address the doppler shift problem of fifth generation wireless communication or future wireless communication (5G +) between in-flight devices and ground devices, which includes using an estimated doppler shift buffer to frequency shift compensate one or more of the following based on navigation data received from a GNSS (e.g., relative position between the gNB and the aircraft and aircraft speed): a received signal of the flying UE, a transmitted signal of the aircraft UE, a received signal of the gNB, and a transmitted signal of the gNB.

Example 2: GNSS assisted cell acquisition, measurement and handover target cell selection

In another embodiment, a system and method for providing GNSS assisted cell acquisition, measurement and handover target selection is described.

In contrast to conventional ground UEs, flying UEs on board an aircraft typically already have a specific predetermined route according to the aircraft flight plan, which facilitates cell acquisition, measurement and handover.

In one embodiment, the in-flight UE may be pre-configured to store information about the distribution of cells within the connection network and/or a subset of the distribution of cells located along or near the aircraft-specific flight path according to the flight plan. Alternatively, the terrestrial network may be configured to provide the cell distribution or part of its related information to the in-flight UE, e.g. uploaded from the terrestrial network to the in-flight UE in a communication connection.

Additionally, the in-flight UE, the cellular ground network, or a combination thereof may be configured to obtain the location of the aircraft by GNSS or other means before and during flight.

Using the GNSS derived flighting data and location data, the flying UE may be configured to determine a subset of cells, i.e., a limited number of candidate cells, for cell search rather than selecting from hundreds (or thousands) of 5G cells throughout the network. Thus, the performance and complexity of cell acquisition may be significantly improved based on a search within a small range of a subset of candidate cells rather than a search of all cells of the network.

In fig. 2, an aircraft 200 with a flying UE is shown that is configured to use flight route data to limit the number of cells in the network (i.e., those cells along the flight route) for cell search, cell acquisition, measurement, and handover. Of all cells, fig. 2 shows

candidate cells

101a, 101B, 101c and performs cell search, acquisition, measurement and handover, while 101d, 101E, 101f (shown in dashed lines) are non-candidate cells. All cells are shown at 100a-100f, respectively. Note that fig. 2 is merely used to illustrate the concept and is not drawn to scale.

In some embodiments, the flight UE may be configured to transmit flight route data related to the aircraft to a ground network (gNB). The cellular terrestrial network may prepare and transmit a cell acquisition plan to the in-flight UE. Alternatively or additionally, the flight UE or ground network may adjust the cell acquisition plan as the aircraft travels along its flight path based on the aircraft position data and other navigation data from the GNSS. Thus, using the navigation data and the cell distribution data, the ground network may be configured to determine candidate cells for the in-flight UE to perform measurements and communicate this information from the ground network to the in-flight UE.

In these embodiments, the in-flight UE only needs to make measurements on a limited subset of candidate cells. Therefore, the complexity of measurement and the measurement report can be reduced.

Based on the navigation data and the cell distribution data, the in-flight UE may determine a target cell to handover to and may request the network to make an early preparation for handover. Alternatively, the network may determine the target cell for early handover preparation based on the in-flight UE navigation data and the flight path. In either variation, early handover preparation ensures seamless handover from one cell to the next, allowing the target cell to schedule upcoming in-flight UEs with improved resource preparation.

In some embodiments, navigation data, such as location and related information, for the in-flight UE may be exchanged between the gnbs in advance.

In some embodiments, the in-flight UE on the aircraft may determine that the in-flight UE has flown in proximity to cells 101 a-101 c (fig. 2) based on aircraft position data obtained from the GNSS. Thus, the in-flight UE only needs to search for the cells 101a to 101c, rather than all the cells in the network.

Similarly, in some embodiments, the in-flight UE on the aircraft may determine that the in-flight UE is near the cells 101 a-101 c (fig. 2) based on aircraft location data obtained from GNSS or otherwise, and therefore, does not need to search the entire network, only need to make measurements and report measurements on the cells 101 a-101 c.

Further, in some embodiments, the in-flight UE on the aircraft may determine that the in-flight UE is moving from cell 101a to cell 101b based on the aircraft location data and the cell distribution data obtained from the GNSS (fig. 2). The in-flight UE may then request early preparation for handover between cell 101a and cell 101 b.

Alternatively, the flying UE may indicate the aircraft location and the flight path to cell 101a, and then the ground network may request cell 101b (shown in fig. 2) for early preparation of the flying UE.

GNSS assisted cell acquisition, measurement and handover as described above provides a faster and more efficient protocol for network connectivity along flight paths.

Example 3: GNSS assisted timing advance estimation

In another embodiment, systems and methods for providing GNSS assisted time advance estimation are described for serving wireless communications around a mobile sub-network (such as in-flight).

For initial access, the in-flight UEs need to send a preamble to the gNB for estimating the Timing Advance (TA) to ensure that the received signals from all UEs are within the Cyclic Prefix (CP) to avoid inter-symbol interference (ISI) and inter-carrier interference (ICI).

The actual TA depends on the distance between the in-flight UE and the gNB, and it must be sufficient to cover the transmission delay to and from the UE and the gNB. For example, when the UE is flying a distance of gNB10 km, the corresponding TA may be 67 μ s; however, when the distance is 50km, TA may be 333 μ s. While the preamble format in FR1 can support such a large TA, the preamble format in FR2 does not.

In the connected state, the gNB may also issue TA commands to calibrate the UE transmit time, if needed. But the current TA command in the connected state can support only a limited TA range.

Therefore, it is proposed in embodiments of the present application that the in-flight UE can obtain its position and distance from the gNB and calculate the coarse TA accordingly. The location of the gNB is fixed and may be stored as network data. However, the location of the aircraft is constantly changing and location information obtained from GNSS may be prioritized. At any time (t), the in-flight UE may obtain (e.g., download) and use the gNB location data and the aircraft location data obtained from the GNSS to determine the distance between the aircraft and the gNB. From the navigation data (e.g., position and velocity) of the aircraft, the flying UE may predict a future distance between the flying UE and the gNB. This information may be stored in memory and may be updated from time to time, or may be retrieved only when needed.

In a preferred embodiment, the in-flight UE transmits an uplink signal with a timing advance based on the estimated coarse TA. For example, assuming that the in-flight UE needs to transmit signal x (t), with TA pre-compensation from GNSS (TA _ 1), the in-flight UE transmits x (t + TA _ 1). The estimation component of the remaining TAs is provided by the random access procedure or by the TA command. The gNB detects the remaining TA component due to the in-flight UE adjustment time and indicates the remaining TA component (TA _ 2) to the in-flight UE accordingly.

The actual TA that the UE signals is TA _1+ TA _2, and the UE advances its transmission by TA _1+ TA _2.

During initial access, the TA sent by the gNB cannot be negative, so GNSS based TA pre-compensation should be more conservative to ensure that uplink signals with TA _1 do not result in negative TA _2. This can be achieved by effectively backing off TA _1, and in the connected state, TA _2 sent by the gNB may be positive or negative, in which case TA _1 does not need an additional back-off.

Example 4: GNSS assisted power control

In another embodiment, systems and methods for power control with GNSS assistance are described.

Uplink power control is essential in Orthogonal Frequency Division Multiple Access (OFDMA) systems, where the difference in received power from multiple in-flight UEs must be controlled within a reasonable range in order to avoid adjacent carrier interference.

Power control is a function of path loss and/or data rate. When a flying UE is closer to the base station, it may transmit at a lower power than a flying UE located relatively far from the base station. In addition, when the UE needs to support a high data rate, it may transmit at a higher power than an in-flight UE with a low data rate.

Due to the relatively low speed of terrestrial UEs, open loop power control cannot adapt very fast. In addition, the path loss can change very dynamically due to the much higher speed of the flying UE.

In an embodiment, the in-flight UE estimates its path loss to the gNB based on the location of the gNB derived from the GNSS, and the in-flight UE may be configured to update its open loop power control. Based on the GNSS assisted path loss measurements, additional closed loop power control may be superimposed on the updated open loop power. Thus, closed loop power control does not require a very large dynamic range and does not need to be very fast.

Using the predetermined flight path (flight path data) and the GNSS-obtained position (navigation data), the gNB may also estimate the path loss of the flying UE and obtain open-loop power control parameters.

If the power control parameters between the in-flight UE and the gNB are inconsistent within a certain range, e.g., the in-flight UE transmits at a higher power than the path loss requirement, the gNB may choose to schedule fewer time or frequency resources for the in-flight UE to minimize the impact on overall system capacity.

Example 5: GNSS assisted beam prediction and management

In another embodiment, a GNSS assisted system and method for beam prediction for positioning antenna signals is described.

Narrow beam transmission is one aspect of successful implementation of 5G wireless communications.

In one example, multiple antennas are coherently combined to form a narrow beam to provide better penetration capability and high data rates for a flying UE. In another example, a single beam steering antenna may be used to achieve the same or similar results.

Regardless of the beamforming antenna used by the antenna system, narrow beam transmission through beam management is required, which requires synchronization of the in-flight UE and the gNB on the used beam. When the gNB and the in-flight UE are not synchronized on the beam, performance is significantly degraded.

In the embodiment shown in fig. 3, to ensure communication efficiency, GNSS-assisted beam prediction and management is implemented.

For example, the ground network may be configured to obtain and store beam information according to flight routes. Based on the in-flight UE location data, cell 101a;101b may predict that transmitting and receiving beams for aircraft 200 may be switched from 120a beams to 120b beams and then to 121a to 121b beams for communication for in-flight UEs.

Alternatively, based on the in-flight UE's location data, the in-flight UE may be configured to communicate with the network gNB using the predicted transmit Tx beam/receive Rx beam. The procedure is applicable to transmission and reception in the connection state and initial access. For example, in an initial Random Access (RACH) procedure, once FUE reports its UE ID (e.g., IMSI, RNTI), the gNB may use the beam corresponding to FUE for subsequent transmission and reception (e.g., MSG4, see fig. 4).

Example 6: overall system flow

The whole system flow is shown in fig. 4.

In one generalized embodiment, a cellular terrestrial network is represented by base station gNB100 and a mobile sub-network is represented by FUE 210.

FUE is configured to obtain navigation data from GNSS and may be further configured to obtain flight path data.

FUE uses navigation data and flight path data to determine a subset of candidate cells from all cells in a cellular ground network. Alternatively, the candidate cell may be uploaded to the FUE or retrieved from memory.

FUE performs a cell search for a subset of candidate cells (rather than for all cells of the network).

Step 1: the gNB transmits synchronization signals and physical broadcast channel blocks (SSBs) containing Primary Synchronization Signals (PSS) and Secondary Synchronization Signals (SSS), and a Master Information Block (MIB) on the Physical Broadcast Channel (PBCH).

Step 2: the gNB transmits a System Information Block (SIB), which defines scheduling information of other system information blocks and contains information required for initial access on a Physical Downlink Shared Channel (PDSCH).

And step 3: FUE transmits a random access preamble (MSG 1) on a Physical Random Access Channel (PRACH) using the same transmit beam direction as in the forward link receive beam and using GNSS based TA compensation.

And 4, step 4: upon receiving MSG1, the gNB sends two physical data: (i) A Physical Downlink Control Channel (PDCCH) masked with a radio access-radio network temporary identity (RA-RNTI), which carries Downlink Control Information (DCI) required to demodulate the PDSCH; (ii) PDSCH, MAC data carrying random access response message (RAR or MSG 2) and other information.

And 5: after successfully decoding the RAR, based on its location and the power control command indicated in the RAR, the FUE sends a Radio Resource Control (RRC) connection request (MSG 3) on the Physical Uplink Shared Channel (PUSCH) using the radio resources allocated by the reverse link grant specified by the RAR and using the power control parameters.

And 6: the gNB transmits an RRC connection setup message on the PDSCH and control information on the PDCCH required to decode the PDSCH. The gNB uses the FUE-specific beam based on the FUE ID (international mobile subscriber identity (IMSI) or Radio Network Temporary Identifier (RNTI)) received from step 5.

And 7: the FUE is in a connected state and subsequent data and control channels use GNSS based timing advance TA, power control, measurement, handover and beam management.

GNSS assisted wireless communication

Thus, according to the above embodiments, there is disclosed a method for providing wireless communication between a cellular terrestrial network and a mobile sub-network, the method comprising: obtaining navigation data from a Global Navigation Satellite System (GNSS), the navigation data including information associated with at least one of: location, vector direction and speed of the mobile subnetwork; and compensating one or more signal parameters for transmission, reception, or a combination thereof based on the navigation data.

In some embodiments, the mobile sub-network is mounted on an aircraft.

In some embodiments, the method further comprises: determining an estimated doppler shift component of the wireless signal based on the navigation data; the received or transmitted signal is compensated with the estimated doppler shift component.

In some embodiments, the method further comprises: compensating received signals to y (t) e using flying user equipment of a mobile subnetwork ^-j2∏(Δft) To reduce doppler effects, where Δ f is the estimated doppler shift component; wherein the compensation is implemented by the in-flight user equipment of the mobile subnetwork.

In some embodiments, the method further comprises: pre-compensation of transmitted signals to x (t) e using flying user equipment of a mobile subnetwork ^-j2∏(Δft) To reduce the doppler effect, where Δ f is the estimated doppler shift component; wherein the pre-compensation is implemented by the flying user equipment of the mobile subnetwork.

In some embodiments, the method further comprises: transmitting, with a flying user equipment of a mobile subnetwork, at least a portion of navigation data to a gNB of a cellular terrestrial network, the at least a portion of navigation data including information relating to a location and a velocity of the mobile subnetwork; determining an estimated Doppler shift component using a gNB of a cellular ground network; at least one of: compensating the received signal based on the estimated doppler shift component and pre-compensating the transmitted signal based on the doppler shift component prior to transmission; wherein the compensation and/or pre-compensation is implemented by a cellular terrestrial network.

In some embodiments, the method may further comprise: obtaining flight path data; and determining a subset of candidate cells from all cells of the cellular terrestrial network using at least part of the navigation data and the flight path data to implement cell acquisition, measurement and handover functions.

In some embodiments, the method may further comprise: receiving, with a flying user equipment of a mobile subnetwork, navigation data from a GNSS; receiving flight route data; determining a subset of candidate cells based on the navigation data and the flight route data; determining a target cell for handover; and transmits an early handover preparation request to the cellular terrestrial network.

In some embodiments, the method may further comprise: receiving, with a cellular ground network, navigation data from a flying user equipment of a mobile sub-network; receiving flight route data; determining a subset of candidate cells based on the navigation data and the flight route data; determining a target cell for handover; and prepare to switch between cellular terrestrial networks. The in-flight user equipment may be configured to communicate the navigation data to a currently serving gNB of the cellular terrestrial network, and the currently serving gNB of the cellular terrestrial network communicates with a target gNB of the target cell for effecting the handover.

In some embodiments, the method further comprises: determining an estimated Time Advance (TA) parameter of the wireless signal based on the navigation data; and compensates the transmitted signal based on the estimated TA parameter. The estimated TA parameter may be selected as a parameter that ensures that the corresponding TA parameter issued by the cellular terrestrial network is positive.

In some embodiments, the method may further comprise: obtaining flight path data; determining power control parameters for the wireless signals based on the navigation data and the flight path data; the signal is transmitted according to the power control parameter.

In some embodiments, the method may further comprise: estimating, with the flying user equipment of the mobile subnetwork, a path loss to a currently serving gNB of the cellular terrestrial network from the navigation data and the flight route data, and updating the open-loop power control based on the estimated path loss.

In some embodiments, the method may further comprise: estimating a path loss of the flying user equipment from the navigation data and the flight route data using a current serving gNB of the mobile cellular ground network, and updating the open loop power control based on the estimated path loss.

In some embodiments, the method may further comprise: if the in-flight user equipment transmits at a higher power than the path loss requirement, less time or frequency resources are scheduled to the in-flight user equipment to minimize the impact on system capacity, utilizing the currently serving gNB of the cellular terrestrial network.

In some embodiments, the method may further comprise: obtaining flight path data; determining beam parameters of the wireless signals based on the navigation data and the flight path data; transmitting, receiving, or both transmitting and receiving one or more wireless signals based on the determined beam parameters. The transmitting, receiving, or transmitting and receiving one or more wireless signals based on the determined beam parameters may be accomplished by the mobile sub-network during initial access. Alternatively, the transmitting, receiving, or both transmitting and receiving one or more wireless signals may be implemented by a mobile sub-network in a connected state based on the determined beam parameters.

In some embodiments, the mobile sub-network may be mounted on an aircraft train, balloon, drone, or the like.

Although various details, features, and combinations are described in the illustrated embodiments, those skilled in the art will understand that a myriad of possible alternative combinations and arrangements of features and details are disclosed herein. As such, the description is intended to be merely illustrative, and not restrictive. Instead, the spirit and scope of the invention is intended to be determined from the appended claims.

INDUSTRIAL APPLICABILITY

The present invention relates to the field of wireless communications for flight applications.

gNB(100)

gNB A(100a)

gNB B(100b)

gNB C(100c)

gNB D(100d)

gNB E(100e)

gNB F(100f)

Cell A (101 a)

Cell B (101B)

Cell C (101C)

Cell D (101 c)

Cell E (101E)

Cell F (101F)

Forward link (110 a)

Reverse link (110 b)

Transmitting/receiving beam (120 a)

Transmit/receive beam (120 b)

Transmitting/receiving beam (121 a)

Transmitting/receiving wave beam (121 b)

Aerocraft (200)

Flight user equipment (210)

Notebook computer (220 a)

Mobile phone (220 b)

Claims

1. A method for providing wireless communication between a cellular terrestrial network and a mobile sub-network, the method comprising:

obtaining navigation data from a Global Navigation Satellite System (GNSS), the navigation data including information relating to at least one of a location, a vector direction, and a velocity of a moving subnetwork;

updating one or more parameters for signal transmission, reception, or a combination thereof based on the navigation data;

determining a Doppler shift component of a wireless signal estimate based on the navigation data;

compensating the received or transmitted signal with the estimated doppler shift component;

by moving the in-flight user equipment of the sub-network,

transmitting at least a portion of the navigation data to a gNB of a cellular terrestrial network, the at least a portion of the navigation data including information relating to a location and a velocity of a mobile subnetwork; and a gNB through the cellular terrestrial network,

determining an estimated doppler shift component; and

at least one of:

compensating the received signal based on said estimated Doppler shift component, an

Pre-compensating a transmission signal based on the Doppler shift component before transmission; wherein compensation and/or pre-compensation is implemented by the cellular terrestrial network; and

wherein the mobile subnetwork is equipped on an aircraft.

2. The method of claim 1, further comprising:

acquiring flight route data; and

using at least a portion of the navigation data and the flight path data,

a subset of candidate cells is determined from all cells of the cellular terrestrial network to implement cell acquisition, measurement and handover functions.

3. The method of claim 2, further comprising:

by means of the in-flight user equipment in connection with the mobile sub-network,

receiving navigation data from a GNSS;

receiving the flight route data;

determining a subset of the candidate cells based on the navigation data and the flight route data;

determining a target cell for handover; and

transmitting an early handover preparation request to the cellular terrestrial network.

4. The method of claim 2, further comprising:

through the cellular land network,

receiving the navigation data from a flight user device of the mobile subnetwork;

receiving the flight route data;

determining a target cell for handover; and

preparing the cellular terrestrial network for handover.

5. The method of claim 4, wherein the in-flight user equipment transmits the navigation data to a currently serving gNB of the cellular terrestrial network, and the currently serving gNB of the cellular terrestrial network communicates with a target gNB of a target cell to effect a handover.

6. The method of claim 1, further comprising:

determining an estimated Time Advance (TA) parameter of a wireless signal based on the navigation data; and

the transmitted signal is compensated based on the estimated TA parameter.

7. The method of claim 6, further comprising: wherein the selected estimated TA parameter ensures that a corresponding TA parameter issued by the cellular terrestrial network is a positive value.

8. The method of claim 1, further comprising:

obtaining flight path data;

determining a power control parameter for a wireless signal based on the navigation data and the flight path data; and

the signal is transmitted based on the power control parameter.

9. The method of claim 8, further comprising:

by moving the in-flight user equipment of the sub-network,

estimating a path loss to a currently serving gNB of a cellular ground network based on the navigation data and the flight path data, an

Updating open loop power control based on the estimated path loss.

10. The method of claim 8, further comprising:

with the current serving gbb of the mobile cellular terrestrial network,

estimating a path loss to a flying user device from said navigation data and said flight path data, an

The open loop power control is updated based on the estimated path loss.

11. The method of claim 10, further comprising:

if the in-flight user equipment transmits at a higher power than the path loss requirement,

then through the currently serving gbb of the cellular terrestrial network,

fewer time or frequency resources are scheduled for the in-flight user equipment to minimize the impact on system capacity.

12. The method of claim 1, further comprising:

obtaining flight path data;

determining beam parameters of wireless signals based on the navigation data and the flight path data; and

transmitting, receiving, or transmitting or receiving one or more wireless signals based on the determined beam parameters.

13. The method of claim 12, wherein transmitting, receiving, or transmitting or receiving one or more wireless signals based on the determined beam parameters is accomplished with a mobile sub-network during initial access.

14. The method of claim 13, further comprising:

by moving user equipment of a sub-network:

transmitting user identification data to the cellular terrestrial network during the initial access, the transmitting being accomplished with the determined beam parameters; and

gNB over cellular terrestrial network:

-receiving said user identification data in a form of a digital signature,

determining corresponding beam parameters based on said user identification data, and

subsequent return signals and messages are transmitted using the corresponding beam parameters.

15. The method of claim 14, wherein transmitting, receiving, or transmitting or receiving one or more wireless signals based on the determined beam parameters is accomplished by a mobile subnetwork being in a connected state.

16. The method of claim 1, wherein the mobile sub-network is mounted on a train, balloon, or drone.