WO2022047630A1

WO2022047630A1 - Mechanism for enhanced positioning scheme for devices

Info

Publication number: WO2022047630A1
Application number: PCT/CN2020/112896
Authority: WO
Inventors: Wenjian Wang; Kai Zhu
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2020-09-01
Filing date: 2020-09-01
Publication date: 2022-03-10
Also published as: CN116458070A

Abstract

Embodiments of the present disclosure relate to enhanced positioning scheme for devices. According to embodiments of the present disclosure, a solution for enhanced positioning scheme for devices is proposed. A first device receives a signal from a second device and receives a further signal from a third device. The first device determines a distance between the first device and the second device based on TOA of the signal and determines a further distance between the first device and the third device based on propagation loss of the second signal. Location information of the first device is determined based on the distance, the further distance and location information of the second and third devices. In this way, the location of the first device is determined more accurately. The first device is not required to be equipped with positioning function, for example, GNSS and the like. Further, it is effective with strong robust and adaptive capability.

Description

MECHANISM FOR ENHANCED POSITIONING SCHEME FOR DEVICES

FIELD

Embodiments of the present disclosure generally relate to the field of communications, especially in non-terrestrial network and in particular, to a method, device, apparatus and computer readable storage medium for enhanced positioning scheme for devices.

BACKGROUND

Resources and infrastructure are usually limited in remote areas. As a result, it is often difficult for a terrestrial network to provide proper coverage. The main benefits of introducing Non-Terrestrial Network (NTN) is to enable ubiquitous services to terminal devices by extending connectivity in less densely populated areas with extremely low density of devices and the overall cost of deployment may be much less than providing permanent infra-structure on the ground. A solution for new radio (NR) to support NTN has been proposed. However, it has also brought some problems in other aspects, such as, accuracy and efficiency.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for enhanced positioning scheme for devices.

In a first aspect, there is provided a method. The method comprises receiving, at a first device, a first signal from a second device. The method also comprises determining a first distance between the first device and the second device based arrival time of the first signal. The method further comprises receiving a second signal from a third device. The method also comprises determining a second distance between the first device and a third device based on a power of the second signal. The method yet comprises determining first location information of the first device based at least in part on the first distance, the second distance, and second location information of the second and third devices.

In a second aspect, there is provided a method. The method comprises transmitting, at a second device, a first signal to a first device. The method further comprises transmitting to the first device information associated with positioning the first device. The method also transmitting to the first device location information of the second device for determining a location of the first device.

In a third aspect, there is provided a first device. The first device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to receive a first signal from a second device. The first device is also caused to determine a first distance between the first device and the second device based arrival time of the first signal. The first device is further caused to receive a second signal from a third device. The first device is also caused to determine a second distance between the first device and a third device based on a power of the second signal. The first device is yet caused to determine first location information of the first device based at least in part on the first distance, the second distance, and second location information of the second and third devices.

In a fourth aspect, there is provided a second device. The second device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to transmit a first signal to a first device. The second device is also caused to transmit to the first device information associated with positioning the first device. The second device is further caused to transmit to the first device location information of the second device for determining a location of the first device.

In a fifth aspect, there is provided an apparatus. The apparatus comprises means for receiving, at a first device, a first signal from a second device; means for determining, at a first device, a first distance between the first device and the second device based arrival time of the first signal; means for receiving a second signal from a third device; means for determining a second distance between the first device and a third device based on a power of the second signal; and means for means for determining first location information of the first device based at least in part on the first distance, the second distance, and second location information of the second and third devices.

In a sixth aspect, there is provided an apparatus. The apparatus comprises means for transmitting, at a second device, a first signal to a first device; means for transmitting to the first device information associated with positioning the first device; and means for transmitting to the first device location information of the second device for determining a location of the first device.

In a seventh aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method according to any one of the above first or second aspect.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

Fig. 1 illustrates an example communication network in which embodiments of the present disclosure may be implemented;

Fig. 2 illustrates a schematic diagram of interactions among communication devices according to embodiments of the present disclosure;

Figs. 3A and 3B illustrate schematic diagrams of positioning a device according to embodiments of the present disclosure;

Fig. 4 illustrates a flowchart of a method implemented at a first device according to embodiments of the present disclosure;

Fig. 5 illustrates a flowchart of a method implemented at a second device according to embodiments of the present disclosure;

Fig. 6 illustrates a simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure; and

Fig 7 illustrates a block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) , New Radio (NR) , Non-terrestrial network (NTN) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.85G, the third generation (3G) , the fourth generation (4G) , 4.5G, the future fifth generation (5G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

As mentioned above, the NTN has also brought some problems in other aspects. Conventionally, it has approved new study item (SI) solution evaluation for NR to support NTN. Among the objectives of the SI, UE location has been identified in TR 38.811 and 38.821that the related positioning information in NTN is beneficial for initial synchronization, uplink timing advance, random access, and mobility in terms of delay compensation, Doppler compensation, Located country identification, and Mobility trigger. Other research also has raised the issue of positioning to identify the located countries for NTN UEs. The NTN requirement for UE positioning are discussed from the following scenarios:

(1) Delay compensation:

There would be a benefit from knowing the position as the timing advance is largely predictable from the satellite positions and movements for a given location on earth. In NTN, the timing advance (TA) for one UE could be divided into satellite-specific common delay and UE-specific differential delay, where the satellite-specific common delay is known due to predictable satellite motion and can be broadcasted to the UE. The UE-specific differential delay can be estimated based on the random access preamble, and/or based on the UE positioning information. The UE positioning information can be derived at the UE side by using Global Navigation Satellite System (GNSS) positioning and/or other positioning solutions and/or derived at the network side. Therefore, it is proposed to study the mechanism of UE-positioning-information-based uplink timing advance in this SI for NTN. The uplink timing advance of one UE might be changed due to the relative motion of this UE and its serving satellite, where the speed of the UE is about up to 1000 km/h, and the orbital speed of the serving satellite is up to [27000] km/h. Therefore, the UE-positioning-information-based uplink timing advance adjustment due to the relative motion of UE and satellite also can be studied.

(2) Frequency compensation:

The acquisition times of Doppler shift can be lowered if the network knows the location of the UEs. Therefore, it is proposed to study UE positioning for the Doppler pre-compensation in NTN.

(3) Located country identification:

NTN is expected to provide global or at least multi-country coverage. This imposes new challenges as compared to the national terrestrial networks. It has discussed this and concluded that it important to know the location of a UE at country level.

(4) Mobility trigger

There is a strong varying delay between the satellite and UE because they are fast-moving and are not relatively static. As a result, the duration of staying in the given spotbeam for a given UE is very short, which will lead the frequently handover problems from the serving spot beam or satellite to the new target spot beam or new target satellite. The individual timing advances of the UEs also have to be fast updated dynamically and appropriate TA index values are needed.

In RAN2#105, it was agreed that UE location and satellite ephemeris information would be beneficial to be considered as an additional input for accuracy of mobility triggers in case of NTN. Especially in Low Earth Orbit (LEO) scenarios, as mentioned above, the impact of relative motion of UE and its serving satellite, UE and/or satellite velocity, large and varying propagation delay on validity of measurements and dynamic neighbour cell change were identified as some of the key issues to address for NTN.

Conventionally, GNSS positioning makes use of UEs that are equipped with radio receivers capable of receiving GNSS signals for UE positioning. The traditional GNSS include Global Positioning System (GPS) , Modernized GPS, Galileo, Global Navigation Satellite System (GLONASS) , Space Based Augmentation Systems (SBAS) , Quasi Zenith Satellite System (QZSS) , and BeiDou Navigation Satellite System (BDS) . Different GNSSs can be used separately or in combination to determine the location of a UE. However, not all of the UEs are GNSS-enabled. The system should also work without GNSS.

There are some conventional geolocation techniques including time-of-arrival (TOA) , time-difference-of-arrival (TDOA) , angle-of-arrival (AOA) and received signal strength indication (RSSI) methods. For TOA-based scheme, the distance from the UE to gNB is directly proportional to the propagation time. The UE and gNBs in the TOA-based systems have to be precisely synchronized. Rather than the absolute arrival time of TOA, TDOA-based systems makes use of the measured arrival time difference of downlink signals received from multiple gNBs at the UE. For TDOA-based systems, synchronization among gNBs is also required. Moreover, the conventional TDOA method need enough number of gNBs within one time window, however, there may not be multiple gNBs visible within this time window. Therefore, TDOA does not work well for NTN networks. The AOA measurements can be made without the requirement of the synchronization. The location of the UE can be found by the intersection of several pairs of angle direction lines. However, it is also sensitive to the lack of line-of-sight (LOS) path. Further, there is also work ongoing on positioning in the NR SI, but the scope is different as very accurate positioning is targeted and moreover the studied solutions are after network access. Therefore the solution for initial UE-based positioning no later than initial access procedure will be expected.

According to embodiments of the present disclosure, a solution for enhanced positioning scheme for devices is proposed. A first device receives a signal from a second device and receives a further signal from a third device. The first device determines a distance between the first device and the second device based on TOA of the signal and determines a further distance between the first device and the third device based on propagation loss of the second signal. Location information of the first device is determined based on the distance, the further distance and location information of the second and third devices. In this way, the location of the first device is determined more accurately. The first device is not required to be equipped with positioning function, for example, GNSS and the like. Further, it is effective with strong robust and adaptive capability.

Fig. 1 illustrates a schematic diagram of a communication environment 100 in which embodiments of the present disclosure can be implemented. The communication environment 100, which is a part of a communication network, further comprises a device 110-1, a device 110-2, ...., a device 110-N, which can be collectively referred to as “first device (s) 110. ” The communication environment 100 comprises a device 120-1, ..., 120-M, which can be collectively referred to as “second device (s) 120. ” The communication environment 100 also comprises a device 130-1, ..., 130-P, which can be collectively referred to as “third device (s) 130. ” The numbers N, M and P can be any suitable integer numbers. The first device 110 and the second device 120 can communicate with each other and the first device 110 can also communicate with the third device 130. Only for the purpose of illustrations, the second device 120 is described as a non-terrestrial device (for example, a satellite) and the third device 130 is described as a terrestrial device (for example, a terrestrial wireless local area network (WLAN) access point) .

The communication environment 100 may comprise any suitable number of devices and cells. In the communication environment 100, the first device 110 and the second device 120 can communicate data and control information to each other. In the case that the first device 110 is the terminal device and the second device 120 is the network device, a link from the second device 120 to the first device 110 is referred to as a downlink (DL) , while a link from the first device 110 to the second device 120 is referred to as an uplink (UL) . The second device 120 and the first device 110 are interchangeable.

It is to be understood that the number of first devices and cells and their connections shown in Fig. 1 is given for the purpose of illustration without suggesting any limitations. The communication environment 100 may include any suitable number of devices and networks adapted for implementing embodiments of the present disclosure.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Reference is now made to Fig. 2, which illustrates a signaling flow 200 for positioning devices. For the purpose of discussion, the signaling flow 200 will be described with reference to Fig. 1. The signaling flow 200 may involve the first device 110-1, the second device 120-1 and the third device 130-1.

The second device 120-1 transmits 2005 a first signal to the first device 110-1. For example, the second device 120-1 may transmit pilot signals to the first device 110-1. Alternatively, the first signal may be a reference signal. In some example embodiments, the second device 120-1 may transmit 2010 synchronization information to the first device 110-1. For example, the first device 110-1 may detect the synchronization signal to complete synchronization. In some embodiments, the synchronization information may be transmitted in a synchronization signal block (SSB) . The first device 110-1 may obtain 2015 identification from the synchronization information. For example, the SSB may carry a flag, for example, one-bit information. The one-bit information may indicate that the second device 120-1 is a non-terrestrial network device, for example, a satellite. In this situation, the first device 110-1 may adopt an interference compensation scheme due to excessively delay in NTN in frequency domain to improve the CSI accuracy.

The first device 110-1 determines 2020 a first distance between the first device 110-1 and the second device 120-1 based on the arrival time of the first signal. Only for the purpose of illustrations, the transmission signal from all candidate APs including the second device 120 and the third device 130 may suffer from the channel effects. The channel model can be described as:

S _r=γHS _t+N (1)

where S _t represents a sending signal, a receiving signal is represented as S _r, a channel response is represented as H, an attenuation factor is represented as γ, additional noise is represented as N.

If the attenuation factor γis considered to be accurate, the distance d between the AP (for example, the second device 120-1) and the first device 110-1 may figure out according to the Friis transmission equation which is defined as

where P _t represents the power of the transmitted signal, P _r represents the power of the received signal, d is the distance between the AP (for example, the second device 120-1) and the first device 110-1, λ i represents s the wavelength and the antenna gains of the transmitting and receiving antennas are represented as G _t and G _r, respectively.

In some embodiments, as mentioned above, the synchronization information may indicate that the second device 120-1 is a non-terrestrial network device. In this situation, the first device 110-1 may determine the arrival time of the first signal.

The first device 110-1 may determine 2025 quality of channel between the first device 110-1 and the second device 120-1. For example, the quality of channel may be determined based on the first signal. Alternatively, the Null signals may be used instead of part of the pilot signals for channel estimation and compensation.

If the quality of the channel is below threshold quality, the first device 110-1 may inform the second device 120-1 that the quality of the channel is poor. For example, the first device may transmit 2030 a preamble to the second device 120-1 in Message 1, which may comprise an indication that the second device 120-1 needs to do interference compensation in the next several symbols until the channel quality exceeds the threshold quality. Alternatively or in addition, the preamble may also indicate to improve channel state information (CSI) accuracy in the next several symbols until the channel quality exceeds the threshold quality.

In some embodiments, the first device 110-1 may receive information indicating that an estimated distance between the first device and the second device exceeds a first threshold distance. In this situation, the first device 110-1 may determine the first distance based on the arrival time.

The first device 110-1 may receive other signals from other devices, for example, the devices 120-2, 120-3, ..., 120-i (not shown) . The non-terrestrial information source set can be represented as:

{i, ||RSSI _i-RSSI _α|≤κ} (3)

where RSSI _i represents the neighbouring device 120-i, RSSI _α represents the maximum RSSI non-terrestrial device which has potential to be selected as the serving device of the first device 110-1 and κ represents a threshold RSSI.

The third device 130-1 transmits 2035 a second signal to the first device 110-1. For example, the third device 130-1 may transmit pilot signals to the first device 110-1. Alternatively, the second signal may be a reference signal. In some example embodiments, the third device 130-1 may transmit synchronization information to the first device 110-1. For example, the first device 110-1 may detect the synchronization signal to complete synchronization. In some embodiments, the synchronization information may be transmitted in a synchronization signal block (SSB) . If the first device 110-1 does not obtain a non-terrestrial network device identification from the synchronization information, it means that the third device 130-1 is a terrestrial network device. In this situation, the channel between the first device 110-1 and the third device 130-1 may almost follow the Rayleigh distribution and the channel response varies around 1. Thus, the power averaging and maximum path selection scheme may be used to estimate the attenuation factor γ and do the distance estimation.

The first device 110-1 determines 2040 a second distance between the first device 110-1 and the second device 120-1 based on a power of the second signal. For example, the first device 110-1 may determine a Received Signal Strength Indicator (RSSI) of the second signal. In some embodiments, the first device 110-1 may measure Reference Signal Receive Power (RSRP) of the second signal. Alternatively or in addition, the first device 110-1 may measure Reference Signal Received Quality (RSRQ) of the second signal.

It should be noted that the first device 110-1 may receive the second signal prior to the first signal. In other words, the above procedures may be implemented in other order.

In some embodiments, to maintain the estimation error less than a threshold value (for example, 30m) , the maximum distance between the first device and the AP (for example, the second device 120-1 and the third device 130-1) is about 500m in terms of Cramer-Rao Lower Bound (CRLB) while the TOA based scheme could perform well for long distance positioning. Therefore, the RSSI scheme may be more appropriate for the terrestrial APs.

In some embodiments, a first threshold distance may be introduced to optimize and balance the CRLB of RSSI and TOA. The first threshold distance may be represented as:

where c represents the light speed, ε=4, η=8, SNR=0dB for a typical scenario in outdoor geolocation, W represents the signal bandwidth. Whend _i＜d _ref, the RSSI may perform better that the TOA method and vice versa.

As mentioned above, if the information indicates that the estimated distance between the first device and the second device exceeds a first threshold distance (i.e., d _i＞d _ref) , the first device 110-1 may determine the first distance based on the arrival time. In some embodiments, the prior informationd _i＞d _ref could be known at the deployment of the second device 120-1 and this information may be signalling when sending the SSBs so that the first device 110-1 could use TOA scheme.

Alternatively or in addition, the first device 110-1 may determine a second threshold distance based on the first threshold distance and a signal-to-noise (SNR) ratio between the first device 110-1 and the third device 130-1. For example, the first device 110-1 may calculate the modified d _ref' value (i.e., the second threshold distance) based on current SNR. If the second distance exceeds the second threshold distance, the second distance needs to be recalculated.

The first device 110-1 may receive other signals from other devices, for example, the devices 130-2, 130-3, ..., 130-n (not shown) . The terrestrial information source set can be represented as:

{n, ||RSSI _n-RSSI _β|≤μ} (5)

where RSSI _n represents the neighbouring device 130-n, RSSI _β represents maximum RSSI of the terrestrial device, and μ represents a threshold RSSI.

The first device 110-1 determines 2045 location information of the first device 110-1 based on the first distance, the second distance and further location information of the second device 120-1 and the third device 130-1. In some embodiments, the first device 110-1 may obtain the location information of the second device 120-1 and ephemeris of the second device 120-1 from system information transmitted by the second device 120-1. In some embodiments, the first device 110-1 may determine a first reliability factor of the second device 120-1 based on the received power of the first signal. Alternatively or in addition, the first device 110-1 may determine a second reliability factor of the third device 130-1 based on the received power of the second signal. For example, the reliability factor may be determined as:

η _i=P _ri/|P′ _ri-P _ri| (6)

where the parameter “i” represents the i ^th device, P′ _ri represents the received signal power of the i ^th device through an actual channel and P _ri represents the received signal power through a perfect channel. The P′ _ri can be determined as:

where the parameter “i” represents the i ^th device, P′ _ri represents the received signal power of the i ^th device through an actual channel, H represents the channel response, P _t is the power of the transmitted signal, d is the distance between the AP (for example, the second device 120-1) and the first device 110-1, λ represents the wavelength, the antenna gains of the transmitting and receiving antennas are represented asG _t and G _r, respectively and N represents the noise on the channel.

Figs. 3A and 3B illustrates a schematic diagram 300 of positioning a device according to embodiments of the present disclosure. As shown in Fig. 3A, there are 7 APs including four non-terrestrial devices (for example, the second devices 120-1, 120-2 and 120-3) and three terrestrial devices (for example, the third devices 130-1, 130-2 and 130-3) . It should be noted that the number of APs shown in Fig. 3A is only an example. Fig. 3B shows an example for adaptive terrestrial APs selection and UE location. As shown in Fig. 3B, there are three APs, for example, the second device 120-1, the third device 130-1 and the third device 130-2. It should be noted that the number of APs shown in Fig. 3B is only an example. The location information of the first device 110-1 may be determined as:

where (X _UE, Y _UE, Z _UE) represents the location of the first device 110-1, D _i represents the estimated distance from the i ^th AP (for example, the first distance and the second distance) , η _i is the weighted factor that indicate the reliability of the i ^th AP, (a _i, b _i, c _i) represents the location of the i ^th AP.

Table 1 below shows performance analysis according to embodiments of the present disclosure. The system is work on S band (2GHz) and the attenuation model is Friis with Rayleigh fading channel model, the transmitting signal strength from AP is 23dBm. The white noise is -90dBm. The first device 110-1 may move from the center point AP1 (shown as the third device 130-1 in Figs. 3A and 3B) outwards with the maximum d1 with 400m.

Table 1

According to embodiments of the present disclosure, the distance between the terminal device and a terrestrial AP is determined using RSSI-based power averaging scheme or maximum path selection scheme in the time domain for low complexity. In the scenario of a non-terrestrial AP, an interference compensation scheme due to excessively delay in NTN in frequency domain is applied to improve the CSI accuracy. In this way, the CSI quality is improved. The location of the terminal device may be determined more accurately. Further, it is effective with strong robust and adaptive capability.

Fig. 4 shows a flowchart of an example method 400 in accordance with some embodiments of the present disclosure. The method 400 may be implemented at any suitable devices. For the purpose of discussion, the method 400 will be described from the perspective of the first device 110-1 with reference to Fig. 1.

At block 410, the first device 110-1 receives a first signal from the second device 120-1. For example, the first device 110-1 may receive pilot signals from the second device 120-1. Alternatively, the first signal may be a reference signal. In some example embodiments, the first device 110-1 may receive synchronization information from the second device 120-1. For example, the first device 110-1 may detect the synchronization signal to complete synchronization. In some embodiments, the synchronization information may be transmitted in a synchronization signal block (SSB) . The first device 110-1 may obtain 2015 identification from the synchronization information. For example, the SSB may carry a flag, for example, one-bit information. The one-bit information may indicate that the second device 120-1 is a non-terrestrial network device, for example, a satellite. In this situation, the first device 110-1 may adopt an interference compensation scheme due to excessively delay in NTN in frequency domain to improve the CSI accuracy.

At block 420, the first device 110-1 determines a first distance between the first device 110-1 and the second device 120-1 based on the arrival time of the first signal. In some embodiments, as mentioned above, the synchronization information may indicate that the second device 120-1 is a non-terrestrial network device. In this situation, the first device 110-1 may determine the arrival time of the first signal.

In some embodiments, the first device 110-1 may determine quality of channel between the first device 110-1 and the second device 120-1. For example, the quality of channel may be determined based on the first signal. Alternatively, the Null signals may be used instead of part of the pilot signals for channel estimation and compensation.

If the quality of the channel is below threshold quality, the first device 110-1 may inform the second device 120-1 that the quality of the channel is poor. For example, the first device may transmit a preamble to the second device 120-1 in Message 1, which may comprise an indication that the second device 120-1 needs to do interference compensation in the next several symbols until the channel quality exceeds the threshold quality. Alternatively or in addition, the preamble may also indicate to improve channel state information (CSI) accuracy in the next several symbols until the channel quality exceeds the threshold quality.

At block 430, the first device 110-1 receives a second signal from the third device 130-1. For example, the first device 110-1 may receive pilot signals from the third device 130-1. Alternatively, the second signal may be a reference signal. In some example embodiments, the first device 110-1 may transmit synchronization information from the third device 130-1. For example, the first device 110-1 may detect the synchronization signal to complete synchronization. In some embodiments, the synchronization information may be transmitted in a synchronization signal block (SSB) . If the first device 110-1 does not obtain a non-terrestrial network device identification from the synchronization information, it means that the third device 130-1 is a terrestrial network device. In this situation, the channel between the first device 110-1 and the third device 130-1 may almost follow the Rayleigh distribution and the channel response varies around 1. Thus, the power averaging and maximum path selection scheme may be used to estimate the attenuation factor γ and do the distance estimation.

At block 440, the first device 110-1 determines a second distance between the first device 110-1 and the second device 120-1 based on a power of the second signal. For example, the first device 110-1 may determine a Received Signal Strength Indicator (RSSI) of the second signal. In some embodiments, the first device 110-1 may measure Reference Signal Receive Power (RSRP) of the second signal. Alternatively or in addition, the first device 110-1 may measure Reference Signal Received Quality (RSRQ) of the second signal.

In some embodiments, a first threshold distance may be introduced to optimize and balance the CRLB of RSSI and TOA. As mentioned above, if the information indicates that the estimated distance between the first device and the second device exceeds a first threshold distance (i.e., d _i＞d _ref) , the first device 110-1 may determine the first distance based on the arrival time. In some embodiments, the prior informationd _i＞d _ref could be known at the deployment of the second device 120-1 and this information may be signaling when sending the SSBs so that the first device 110-1 could use TOA scheme.

It should be noted that the blocks 410-440 may take place in any suitable order. For example, the first device 110-1 may receive the second signal prior to the first signal. Alternatively or in addition, the first device 110-1 may receive the first and second signals simultaneously. The first distance may be determined prior to receiving the second signal or after receiving the second signal. Embodiments are not limited in this aspect.

At block 450, the first device 110-1 determines 2045 location information of the first device 110-1 based on the first distance, the second distance and further location information of the second device 120-1 and the third device 130-1. In some embodiments, the first device 110-1 may determine a first reliability factor of the second device 120-1 based on the received power of the first signal. Alternatively or in addition, the first device 110-1 may determine a second reliability factor of the third device 130-1 based on the received power of the second signal.

Fig. 5 shows a flowchart of an example method 500 in accordance with some embodiments of the present disclosure. The method 500 may be implemented at any suitable devices. For the purpose of discussion, the method 500 will be described from the perspective of the second device 120-1 with reference to Fig. 1. It should be noted that the method 500 may also be implemented at the third device 130-1.

At block 510, the second device 120-1 transmits a first signal to the first device 110-1. For example, the second device 120-1 may transmit pilot signals to the first device 110-1. Alternatively, the first signal may be a reference signal.

At block 520, the second device 120-1 transmits information associated with positioning the first device. In some embodiments, if the second device 120-1 is a non-terrestrial network device, the information may comprise an indication concerning that the second device is a non-terrestrial network device. For example, the indication may be in SSB. Alternatively, the information may comprise an indication concerning that an estimated distance between the first device and the second device exceeds a first threshold distance.

In some embodiments, the information may be transmitted in Radio Resource Control (RRC) signaling. Alternatively, the information may be broadcasted. In other embodiment, downlink control information may comprise the above information.

Only for the purpose of the illustrations, in the scenario where the second device is a satellite, the information may comprise one or more of the following: (1) satellite identification information; (2) defining the UE behaviour when the UE do not receive the satellite identification in SSB where the signal is regarded to come from the terrestrial AP signal; (3) UE triggering the interference compensation scheme due to NTN long propagation delay to improve the CSI quality. For example, if the quality of channel between the first device 110-1 and the second device 120-1 is below the threshold quality, the second device 120-1 may receive a preamble in Message 1 from the first device 110-1. The preamble may comprise an indication for interference compensation on the channel. The second device 120-1 may perform the interference compensation based on the preamble.

At block 530, the second device 120-1 may transmit location information of the second device 120-1 to the first device 110-1. For example, the location information may be transmitted in system information.

In some embodiments, an apparatus for performing the method 400 (for example, the first device 110-1) may comprise respective means for performing the corresponding steps in the method 400. These means may be implemented in any suitable manners. For example, it can be implemented by circuitry or software modules.

In some embodiments, the apparatus comprises means for receiving, at a first device, a first signal from a second device; means for determining, at a first device, a first distance between the first device and the second device based arrival time of the first signal; means for receiving a second signal from a third device; means for determining a second distance between the first device and a third device based on a power of the second signal; and means for determining first location information of the first device based at least in part on the first distance, the second distance, and second location information of the second and third devices.

In some embodiments, the apparatus further comprises means for determining quality of a channel between the first device and the second device; and means for in accordance with a determination that the quality of the channel is below threshold quality, transmitting to the second device a preamble for accessing the channel between the first device and the second device, the preamble comprising an indication for interference compensation on the channel.

In some embodiments, the means for determining the first distance comprises: means for receiving from the second device synchronization information; means for in accordance with a determination that the synchronization information comprising an indication concerning that the second device is a non-terrestrial network device, determining the arrival time of the first signal; and means for determining the first distance based on the arrival time.

In some embodiments, the means for determining the second distance comprises: means for receiving from the third device synchronization information; means for in accordance with a determination that the synchronization information is free from an indication concerning that the third device is a non-terrestrial network device, determining the power of the second signal; and means for determining the second distance based on the power.

In some embodiments, the means for determining the first distance comprises: means for receiving from the second device information indicating that an estimated distance between the first device and the second device exceeds a first threshold distance; means for determining the arrival time of the first signal; and means for determining the first distance based on the arrival time.

In some embodiments, the apparatus further comprises means for determining a second threshold distance based on the first threshold distance and a signal-to-noise ratio between the first device and the third device; means for comparing the second distance with the second threshold distance; and means for in accordance with a determination that the second distance exceeds the second threshold distance, recalculating the second distance.

In some embodiments, the means for determining the first location information of the first device comprises: means for determining a first reliability factor of the second device based on a received power of the first signal; means for determining a second reliability factor of the third device based on the power of the second signal; and means for determining the first location information based on the first distance, the second distance, the first reliability factor, the second reliability factor and the second location information of the second and third devices.

In some embodiments, an apparatus for performing the method 500 (for example, the second device 120-1) may comprise respective means for performing the corresponding steps in the method 500. These means may be implemented in any suitable manners. For example, it can be implemented by circuitry or software modules.

In some embodiments, the apparatus comprises means for transmitting, at a second device, a first signal to a first device; means for transmitting to the first device information associated with positioning the first device; and means for transmitting to the first device location information of the second device for determining a location of the first device.

In some embodiments, the apparatus further comprises means for in accordance with a determination that quality of a channel between the first device and the second device is below threshold quality, receiving from the first device a preamble for accessing the channel between the first device and the second device, the preamble comprising an indication for interference compensation on the channel.

In some embodiments, the information comprises: an indication concerning that the second device is a non-terrestrial network device, or an indication concerning that an estimated distance between the first device and the second device exceeds a first threshold distance.

Fig. 6 is a simplified block diagram of a device 600 that is suitable for implementing embodiments of the present disclosure. The device 600 may be provided to implement the communication device, for example, the first device 110-1, the second device 120-1 or the third device 130-1 as shown in Fig. 1. As shown, the device 600 includes one or more processors 610, one or more memories 62620 coupled to the processor 610, and one or more communication module (for example, transmitters and/or receivers (TX/RX) ) 640 coupled to the processor 610.

The communication module 640 is for bidirectional communications. The communication module 640 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

The processor 610 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 600 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 62620 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 624, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 622 and other volatile memories that will not last in the power-down duration.

A computer program 630 includes computer executable instructions that are executed by the associated processor 610. The program 630 may be stored in the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

The embodiments of the present disclosure may be implemented by means of the program 630 so that the device 600 may perform any process of the disclosure as discussed with reference to Figs. 2 to 5. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 62620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. Fig. 7 shows an example of the computer readable medium 700 in form of CD or DVD. The computer readable medium has the program 630 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the methods 200-400 as described above with reference to Figs. 2-5. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A first device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to:

receive a first signal from a second device;

determine a first distance between the first and second devices based on arrival time of the first signal;

receive a second signal from a third device;

determine a second distance between the first and third devices based on a power of the second signal; and

determine a location of the first device based at least in part on the first distance, the second distance, and locations of the second and third devices.
The first device of claim 1, wherein the first device is further caused to:

in accordance with a determination that a quality of a channel between the first and second devices is below a threshold quality, transmit to the second device a preamble for accessing the channel between the first device and the second device, the preamble comprising an indication to trigger an interference compensation on the channel.
The first device of claim 1, wherein the first device is further caused to:

receive synchronization information from the second device; and

in accordance with a determination from the received synchronization information that the second device is a non-terrestrial network device, determine the arrival time of the first signal.
The first device of claim 1, wherein the first device is further caused to:

receive synchronization information from the third device; and

in accordance with a determination from the received synchronization information that the third device is a terrestrial network device, determine the power of the second signal.
The first device of claim 1, wherein the first device is further caused to:

receive from the second device information indicating that an estimated distance between the first and second devices exceeds a first threshold distance; and

determine the arrival time of the first signal.
The first device of claim 5, wherein the first device is further caused to:

determine a second threshold distance based on the first threshold distance and a signal-to-noise ratio between the first device and the third device; and

in accordance with a determination that the second distance exceeds the second threshold distance, recalculate the second distance.
The first device of claim 1, wherein the first device is caused to determine the location of the first device by:

determining a first reliability factor of the second device based on a received power of the first signal;

determining a second reliability factor of the third device based on the power of the second signal; and

determining the first location information based on the first distance, the second distance, the first reliability factor, the second reliability factor and the locations of the second and third devices.
The first device of claim 1, wherein the first device comprises a terminal device, the second device comprises a non-terrestrial network device and the third device comprises a terrestrial network device.
A second device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to:

transmit a first signal to a first device;

transmit to the first device information associated with positioning the first device; and

transmit to the first device location information of the second device for determining a location of the first device.
The second device of claim 9, wherein the second device is further caused to:

in accordance with a determination that a quality of a channel between the first and second devices is below a threshold quality, receive from the first device a preamble for accessing the channel between the first and second devices, the preamble comprising an indication to trigger an interference compensation on the channel.
The second device of claim 9, wherein the information comprises:

an indication concerning that the second device is a non-terrestrial network device, or

an indication concerning that an estimated distance between the first device and the second device exceeds a first threshold distance.
The second device of claim 9, wherein the first device comprises a terminal device, the second device comprises a non-terrestrial network device or a terrestrial network device.
A method comprising:

receiving, at a first device, a first signal from a second device;

determining a first distance between the first and second devices based on arrival time of the first signal;

receiving a second signal from a third device;

determining a second distance between the first and third devices based on a power of the second signal; and

determining a location of the first device based at least in part on the first distance, the second distance, and locations of the second and third devices.
The method of claim 13, further comprising:

in accordance with a determination that a quality of a channel between the first and second devices is below a threshold quality, transmitting to the second device a preamble for accessing the channel between the first device and the second device, the preamble comprising an indication to trigger an interference compensation on the channel.
The method of claim 13, further comprising:

receiving synchronization information from the second device; and

in accordance with a determination from the received synchronization information that the second device is a non-terrestrial network device, determine the arrival time of the first signal, determining the arrival time of the first signal.
The method of claim 13, further comprising:

receiving synchronization information from the third device; and

in accordance with a determination from the received synchronization information that the third device is a terrestrial network device, determining the power of the second signal.
The method of claim 13, further comprising:

receiving from the second device information indicating that an estimated distance between the first and second devices exceeds a first threshold distance; and

determining the arrival time of the first signal.
The method of claim 17, further comprising:

determining a second threshold distance based on the first threshold distance and a signal-to-noise ratio between the first device and the third device; and

in accordance with a determination that the second distance exceeds the second threshold distance, recalculating the second distance.
The method of claim 13, wherein determining the location of the first device comprises:

determining a first reliability factor of the second device based on a received power of the first signal;

determining a second reliability factor of the third device based on the power of the second signal; and

determining the first location information based on the first distance, the second distance, the first reliability factor, the second reliability factor and the locations of the second and third devices.
The method of claim 13, wherein the first device comprises a terminal device, the second device comprises a non-terrestrial network device and the third device comprises a terrestrial network device.
A method comprising:

transmitting, at a second device, a first signal to a first device;

transmitting to the first device information associated with positioning the first device; and

transmitting to the first device location information of the second device for determining a location of the first device.
The method of claim 21, further comprising:

in accordance with a determination that quality of a channel between the first device and the second device is below threshold quality, receiving from the first device a preamble for accessing the channel between the first device and the second device, the preamble comprising an indication for interference compensation on the channel.
The method of claim 21, wherein the information comprises:

an indication concerning that the second device is a non-terrestrial network device, or

an indication concerning that an estimated distance between the first device and the second device exceeds a first threshold distance.
The method of claim 21, wherein the first device comprises a terminal device, the second device comprises a non-terrestrial network device or a terrestrial network device.
A computer readable medium storing instructions thereon, the instructions, when executed by at least one processing unit of a machine, causing the machine to perform the method according to any one of claims 13-20, or the method according to any one of claims 21-24.
An apparatus comprising:

means for receiving, at a first device, a first signal from a second device;

means for determining, at a first device, a first distance between the first and second devices based arrival time of the first signal;

means for receiving a second signal from a third device;

means for determining a second distance between the first and third devices based on a power of the second signal; and

means for determining a location of the first device based at least in part on the first distance, the second distance, and locations of the second and third devices.
An apparatus comprising:

means for transmitting, at a second device, a first signal to a first device;

means for transmitting to the first device information associated with positioning the first device; and

means for transmitting to the first device location information of the second device for determining a location of the first device.