CN114208326A

CN114208326A - Packet-based PRS resource mapping and configuration

Info

Publication number: CN114208326A
Application number: CN201980099156.0A
Authority: CN
Inventors: 孟艳; 陶涛; 刘建国; 沈钢
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2019-08-09
Filing date: 2019-08-09
Publication date: 2022-03-18
Also published as: WO2021026699A1

Abstract

Embodiments of the present disclosure relate to methods, apparatuses, and computer-readable storage media for packet-based Positioning Reference Signal (PRS) resource mapping and configuration. In an example embodiment, a location server determines a set of neighboring base stations based on the geographic locations of the base stations. The location server allocates at least one time domain resource and a set of frequency domain resources for a set of PRSs to be transmitted by a set of neighboring base stations. The location server also sends an indication indicating at least one time domain resource and a set of frequency domain resources to a set of neighboring base stations.

Description

Packet-based PRS resource mapping and configuration

Technical Field

Embodiments of the present invention relate generally to the field of communications, and more particularly, to a method, apparatus, and computer-readable storage medium for packet-based Positioning Reference Signal (PRS) resource mapping and configuration.

Background

Observed time difference of arrival (OTDOA) is a downlink positioning technique in Long Term Evolution (LTE) release 9 (Rel-9). The technology employs a multipoint measurement method in which a User Equipment (UE) measures time of arrival (TOA) of signals received from a plurality of base stations (e.g., enbs). In LTE, Positioning Reference Signals (PRS) have been introduced to allow UEs to make appropriate timing measurements on signals from base stations to improve OTDOA positioning performance.

Positioning techniques for New Radio (NR) systems are being developed in third generation partnership project (3GPP) standardization. The positioning technology needs to enable Radio Access Technology (RAT) dependent positioning to operate in both frequency range 1 (or FR1, also known as sub 6Ghz range) and frequency range 2 (or FR2, also known as millimeter wave range). However, there is no PRS design available in NR systems to enable OTDOA positioning algorithms to achieve higher positioning accuracy.

Disclosure of Invention

In general, example embodiments of the present disclosure provide methods, apparatuses, and computer-readable storage media for packet-based Positioning Reference Signal (PRS) resource mapping and configuration.

In a first aspect, there is provided a location server comprising at least one processor and at least one memory including computer program code. The at least one memory and the computer program code configured to, with the at least one processor, cause the location server to: a set of neighboring base stations is determined based on the geographic locations of the base stations. The method includes causing a location server to allocate at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations. The location server is further caused to transmit an indication indicating the at least one time domain resource and the set of frequency domain resources to a set of neighboring base stations.

In a second aspect, a user equipment is provided that comprises at least one processor and at least one memory including computer program code. The at least one memory and the computer program code configured to, with the at least one processor, cause the user equipment to: an indication is received indicating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations. A set of positioning reference signals transmitted by neighboring base stations. Causing the user equipment to determine a beam direction for receiving the set of positioning reference signals. The user equipment is further caused to receive a set of positioning reference signals in a beam direction on the time domain resources and the frequency domain resources.

In a third aspect, a base station is provided that includes at least one processor and at least one memory including computer program code. The at least one memory and the computer program code configured to, with the at least one processor, cause the base station to: an indication indicating at least time and frequency domain resources for transmitting positioning reference signals is received from a location server. The base station is also caused to transmit positioning reference signals on the time domain resources and the frequency domain resources.

In a fourth aspect, a method is provided. In the method, a location server determines a set of neighboring base stations based on the geographic locations of the base stations. The location server allocates at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations. The location server also sends an indication indicating at least one time domain resource and a set of frequency domain resources to a set of neighboring base stations.

In a fifth aspect, a method is provided. In the method, a user equipment receives an indication indicating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations. The user equipment determines a beam direction for receiving a set of positioning reference signals. The user equipment also receives a set of positioning reference signals in a beam direction on the time domain resources and a set of frequency domain resources.

In a sixth aspect, a method is provided. In the method, a base station receives an indication indicating at least time and frequency domain resources for transmitting positioning reference signals from a location server. The base station also transmits positioning reference signals on the time domain resources and the frequency domain resources.

In a seventh aspect, there is provided an apparatus comprising means for performing a method according to the third or fourth aspect.

In an eighth aspect, a computer-readable storage medium is provided on which a computer program is stored. The computer program, when executed by a processor of the apparatus, causes the apparatus to perform the method according to the third or fourth aspect.

It should be understood that this summary is not intended to identify key or essential features of the embodiments of the disclosure, nor is it intended to be used to limit the scope of the disclosure. Other features of the present disclosure will become readily apparent from the following description.

Drawings

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

figure 1 illustrates an example PRS resource mapping in LTE;

figure 2 illustrates an example PRS resource configuration in LTE;

fig. 3 shows an example scenario in which the gnbs are geographically distant from each other;

FIG. 4 illustrates an example environment in which embodiments of the present disclosure may be implemented;

fig. 5 shows a flow diagram of an example method according to some example embodiments of the present disclosure;

fig. 6 shows a flowchart of an example method according to some other example embodiments of the present disclosure;

fig. 7 illustrates an example use of a group ID in accordance with some example embodiments of the present disclosure;

fig. 8 shows a flowchart of an example method according to some other example embodiments of the present disclosure;

fig. 9 illustrates an example signaling flow 800 between a location server, a base station, and a UE, in accordance with some example embodiments of the present disclosure;

fig. 10 illustrates an example scenario of packet-based PRS transmissions, according to some example embodiments of the present disclosure;

fig. 11 illustrates an example scenario of packet-based PRS transmissions in accordance with some other example embodiments of the present disclosure; and

fig. 12 shows a simplified block diagram of a device suitable for implementing embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numbers refer to the same or similar elements.

Detailed Description

The principles of the present disclosure will now be described with reference to a few exemplary embodiments. It is understood that these examples are described merely to illustrate and assist those of ordinary skill in the art in understanding and enabling the disclosure, and do not imply any limitation on the scope of the disclosure. The disclosure described herein may be implemented in various ways other than those 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 skill in the art to which this disclosure belongs.

As used herein, the term "base station" (BS) refers to a device via which a User Equipment (UE) may access a communication network. Examples of base stations include relays, Access Points (APs), transmission points (TRPs), node bs (NodeB or NB), evolved NodeB (eNodeB or eNB), New Radio (NR) NodeB (gnb), remote radio modules (RRUs), Radio Heads (RH), Remote Radio Heads (RRHs), low power nodes (such as femto, pico, etc.).

As used herein, the term "user plane function" (UPF) refers to a device, function, or component for providing various functions in the user plane in the core network. The UPF may provide interconnections, packet routing and forwarding, etc., between the mobile infrastructure and the data network.

As used herein, the term "user equipment" (UE) refers to a terminal station capable of Time Sensitive Communication (TSC) or a terminal device in wireless communication with a base station. Communication may involve the transmission and/or reception of wireless signals using electromagnetic signals, radio waves, infrared signals, and/or other types of signals suitable for conveying information over the air. Examples of UEs include, but are not limited to, smart phones, wireless-enabled tablets, Laptop Embedded Equipment (LEEs), laptop installation equipment (LMEs), and/or wireless Customer Premise Equipment (CPEs).

As used herein, the term "location server" refers to a device, function, or entity capable of providing location services or management to a UE. As an example, the location server may be a device in a core network of a communication network, such as an evolved serving mobile location center (E-SMLC) that may communicate with the base stations. As another example, the location server may be integrated with the base station.

As used herein, the term "circuitry" may refer to one or more or all of the following:

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

(b) a combination of hardware circuitry and software, such as (as applicable): (i) a combination of analog and/or digital hardware circuit(s) and software/firmware, and (ii) any portion of hardware processor(s) with software (including digital signal processor (s)), software and memory(s) that work together to cause a device, such as a mobile phone or server, to perform various functions, and (ii) a computer program product that includes computer program code for performing various functions

(c) Hardware circuit(s) and/or processor(s), such as microprocessor(s) or a portion of microprocessor(s), require software (e.g., firmware) for operation, but this software may not be present when the software is not required for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As another example, as used in this application, the term circuitry also encompasses implementations of: a hardware circuit or processor (or processors) alone or in part, and the accompanying software and/or firmware (or them). The term circuitry also encompasses, 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 a server, a cellular network device, or other computing or network device.

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. The term "include" and its variants are to be understood as open-ended terms meaning "including, but not limited to". The term "based on" is to be understood as "based at least in part on". The terms "an embodiment" and "an embodiment" are to be understood as "at least one embodiment". The term "another embodiment" should be understood as "at least one other embodiment". Other definitions, explicit and implicit, may be included below.

As used herein, the terms "first" and "second," etc. may be used herein to describe various elements, which should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element may be termed a second element, and, similarly, a second element may 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.

OTDOA has been specified in LTE standardization as a mature positioning technology. In OTDOA positioning, a UE needs to measure a time difference for receiving PRS signals from two or more base stations. In LTE, PRS resources of multiple cells are multiplexed in the frequency domain of one subframe. A cell-specific frequency shift is introduced in the PRS mapping rules.

As an example of this, the following is given,

wherein v is_shiftWhich is indicative of a frequency shift,

represents a physical cell identity (PID) and mod represents a modulo operation. In this case, there are six possible frequency shift modes to achieve the reuse of six cells in the frequency domain. The value of mod (PCI, 6) determines one of six possible frequency arrangements. Thus, the frequency domain resources of PRS can be determined for a cell by mod (PCI, 6)。

Fig. 1 illustrates an example PRS resource mapping 100. In this example, three base stations, represented by gNB #1, gNB #2, and gNB #3, transmit PRSs on the same time domain resource (such as symbol 105), but on different time domain resources to achieve multiplexing in the frequency domain. The frequency domain resources of these base stations may be identified by different mod (PCI, 6) values.

Further, PRSs may be transmitted in predefined positioning subframes grouped by a number of consecutive subframes, which are referred to as "positioning occasions". The positioning timing occurs periodically with a certain period. PRS subframe configurations, such as subframe offset, number of Downlink (DL) consecutive subframes, and PRS periodicity, may be configured separately by each base station.

PRS subframe configuration may also involve PRS muting. As described above, in the case of multiplexing 6 cells in the frequency domain, the frequency domain resource of the PRS may be determined by mod (PCI, 6). Thus, if the cells have the same mod (PCI, 6) value (e.g., PCI 0 and PCI 6), then the PRSs will collide and are no longer orthogonal. In this case, PRS muting can be introduced to make PRS occasions orthogonal to each other.

PRS muting requires that PRSs be transmitted with zero power at certain positioning occasions. For example, if a (strong) PRS received by a UE from its serving base station is muted, a (weak) PRS from a neighboring base station (with the same frequency shift) may be more easily detected by the UE. PRS muting may be configured by the central node.

Fig. 2 illustrates an example PRS resource configuration 200 in LTE. As shown in fig. 2, for a reference time 205 when a subframe number (SFN) is 0 and a slot number is 0, a PRS subframe offset 210 is configured by the base station. The base station also configures PRS occasion 215 and the number of consecutive subframes in PRS period 220. In this example, six cells are multiplexed, and PRS may collide for PCI-0, PCI-6, PCI-12, and PCT-18. The PRS muting patterns for these PCIs are configured accordingly as 1000, 0100, 0010, and 0001, with "1" indicating muting of PRS transmissions in the corresponding transmission occasions 215.

Conventionally, in LTE, the frequency domain resource of PRS may be determined by cell ID. The time domain resources of the PRS may be autonomously configured by the base station without any coordination with neighboring cells or neighboring base stations.

In NR, beamforming has been agreed to improve hearability, especially at least for high frequency bands. For example, in NR systems, receiver (Rx) beamforming needs to be supported to achieve high audibility in high frequency bands. In this case, the PRS resource configuration in LTE seems to be inefficient for NR systems if Rx beamforming is used on the UE side.

For example, with the PRS resource mapping 100 as shown in fig. 1, PRS signals for three gnbs have been configured to be transmitted on one subframe 105 with different subcarriers. The PRS configuration may be autonomously determined by one of the gnbs regardless of the geographic location of the gnbs. If the three gnbs are geographically distant from each other, the UE can only receive one of the PRS signals by using one receive beam direction at one time occasion.

Fig. 3 shows an example scenario 300 in which the gnbs are geographically distant from each other.

As shown in fig. 3, three

gnbs

305, 310, and 315 (represented by gNB #1, gNB #2, and gNB #3) transmit PRSs in the same time instance as shown in fig. 1. In this case, the UE 320 can only receive one of the PRSs at one time occasion by using one of the

reception beam directions

325, 330, and 335. Therefore, the UE 320 needs several time occasions to receive all PRSs of the three

gnbs

305, 310, and 315, which results in a waste of resources.

To date, there is no suitable PRS design in NR systems to enable OTDOA positioning algorithms to achieve high positioning accuracy.

Embodiments of the present disclosure provide a novel PRS resource mapping and configuration scheme to improve resource efficiency in Rx beamforming, e.g., NR systems. The scheme proposes a PRS configuration based on base station grouping. With this scheme, the location server divides the base stations into different groups of neighboring base stations based on their geographic locations. For a set of neighboring base stations, the location server allocates at least one time domain resource and a different set of frequency domain resources for transmission of PRSs. The number of time domain resources may depend on the number of base stations in the group.

As such, a set of PRSs may be transmitted by a set of base stations using different frequency domain resources at one time instance. Thus, the UE may receive a set of PRSs from multiple cells in one beam direction. In contrast to autonomous PRS configuration of base stations in LTE, PRS configuration schemes according to example embodiments of the present disclosure guarantee that neighboring gnbs transmit PRS at one time occasion under control of a location server. In this way, the UE can receive the maximum number of PRSs simultaneously, thereby achieving high resource efficiency.

FIG. 4 shows an example environment 400 in which embodiments of the present disclosure may be implemented. Environment 400, which is part of a communication network, includes a UE410 and a plurality of base stations 420-1, 420-2 … … 420-N (where N represents a positive integer). For purposes of discussion, these base stations will be collectively referred to as base stations 420. Environment 400 also includes a location server 430 that may communicate with base station 420 and with UE410 via base station 420 to provide location services to UE 410.

It should be understood that the number of base stations, UEs, and location servers shown in fig. 4 is for illustration purposes only and does not imply any limitation on the scope of the present disclosure. Environment 400 may include any suitable number of base stations, UEs, and location servers suitable for implementing embodiments of the present disclosure.

UE410 may communicate with base station 420 or with another terminal device or location server 430 or other network entity via base station 420. The communication between the UE410 and the base station 420 may follow any suitable wireless communication standard or protocol, such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), LTE-advanced (LTE-a), fifth generation (5G) NR, wireless fidelity (Wi-Fi), and Worldwide Interoperability for Microwave Access (WiMAX) standards, and employ any suitable communication technology including, for example, multiple-input multiple-output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), Code Division Multiplexing (CDM), bluetooth, ZigBee, and Machine Type Communication (MTC), enhanced mobile broadband (eMBB), large-scale Machine Type Communication (MTC), and ultra-reliable low latency communication (urrllc) techniques.

Location server 430 may communicate with base station 420. The communication between location server 430 and base station 420 may utilize any suitable communication technology. In some example embodiments, location server 430 and base station 420 may communicate over a cable.

As shown in FIG. 4, base stations 420-1 … … 420-N are in geographic proximity to each other. Location server 430 clusters 440 the base stations 420 into groups. It should be understood that one group 440 is shown in environment 400 for illustration purposes only and does not imply any limitation. Environment 400 may include any suitable number of groups 440 of neighboring base stations. For the group 440 of neighboring base stations, the location server 430 allocates the same time domain resources and different frequency domain resources for transmission of PRSs. The UE410 may receive PRSs from the group 440 of base stations using one beam direction 450.

Fig. 5 shows a flowchart of an example method 500 according to some example embodiments of the present disclosure. Method 500 may be implemented by location server 430 as shown in fig. 4. For discussion purposes, the method 500 will be described with reference to fig. 4.

As shown, at block 505, the location server 430 determines a group 440 of neighboring base stations based on the geographic locations of the base stations. The geographic location of the base stations 420 may be determined by the location server 430 based on geographic information received or collected from these base stations 420. In some example embodiments, location server 430 may collect positioning assistance information from surrounding base stations. The positioning assistance information may comprise geographical coordinates of surrounding base stations as geographical information about these base stations. Based on the geographic coordinates, location server 430 may determine which base stations are in proximity to each other and then determine that these base stations form a set of neighboring base stations.

Location server 430 may determine the proximity of base station 420 based on a comparison of the geographic distance between these base stations and a threshold distance. The threshold distance may be pre-configured according to network deployment and actual needs. For example, in an example embodiment where location service 430 obtains geographic coordinates of base stations 420 as geographic information, location server 430 may determine a geographic distance between the base stations based on the corresponding geographic coordinates and then compare the geographic distance to a threshold distance. If the geographic distance between the base stations 420 is below a threshold distance, the location server 430 may determine that the base stations 420 are in proximity to each other.

At block 510, the location server 430 allocates at least one time domain resource and a set of frequency domain resources for a set of PRSs to be transmitted by a set of neighboring base stations 420. The number of time domain resources allocated by location server 430 may depend on the number of base stations in group 440. For example, when the number of base stations in a group is greater than a threshold number, more than one time domain resource may be allocated to the group. The threshold number may depend on the multiplexing of base stations or PRSs in the frequency domain. For example, in the case of frequency domain multiplexing six base stations, the threshold number may be set to 6. Based on the time and frequency resource allocation, multiple PRSs may be transmitted by multiple neighboring base stations 420 at the same time instance using different frequency domain resources.

The time domain resources may include any suitable resources in the time domain. For example, the time domain resources may include transmission occasions for PRSs. Location server 430 may assign a transmission opportunity for a set of neighboring base stations. The frequency domain resources may comprise any suitable resources in the frequency domain. For example, the frequency domain resources may include subcarriers, subbands, and bandwidth parts in the frequency domain. In an example embodiment where the location server 430 may assign different subcarriers to neighboring base stations in a group, the group of neighboring base stations will transmit PRSs on the different subcarriers but at the same time instance.

Furthermore, the time and frequency resources may relate to any other suitable resource configuration. For example, the time domain resources may include a duration of the transmission opportunity, a location of the transmission opportunity, and a period of the transmission opportunity. The frequency domain resources may include cell-specific frequency shifts and PRS bandwidths. In the case of allocating subcarriers, the frequency shift may implicitly indicate the subcarrier index.

In some example embodiments, location server 430 may allocate different time domain resources, such as transmission opportunities, for different groups of base stations. Thus, different groups of base stations transmit PRSs on different time domain resources.

At block 515, the location server 430 sends an indication indicating at least one time domain resource and a set of frequency domain resources to the set of neighboring base stations 440. The indication may be sent to the group of neighboring base stations 440 by using LTE positioning protocol a (lppa) or any other suitable protocol that already exists or will be developed in the future.

In some example embodiments, location server 430 may send an indication to UE410 indicating at least one time domain resource and a set of frequency domain resources, e.g., via a serving cell of UE 410. For example, location server 430 may include information regarding both time and frequency domain resources in assistance data for UE 410. The indication may be sent by reusing existing signaling, such as a provideassistancedata message using the LTE Positioning Protocol (LPP). By reusing existing signaling to transfer time and frequency resources from location server 430 to the base station group, no additional signaling needs to be introduced to provide backward compatibility. It should be appreciated that any other suitable signaling may be used. With time and frequency resources, the UE410 may receive a set of PRSs from a set of neighboring base stations 440 in one beam direction 450.

In some example embodiments, location server 430 may configure a group Identification (ID) to group 440 of neighboring base stations and send the group ID to group 440 of neighboring base stations. Similar to the indication for indicating time and frequency domain resources, the group ID may be indicated to the base station 420 using LPP or any other suitable protocol.

In some example embodiments, location server 430 may send an indication of the group ID to UE 410. The indication may also be included in assistance data of the UE 410. As such, when the number of base stations in the group 440 is large and these base stations 420 are configured with more than one time domain resource, the UE410 may still determine, based on the group ID, that the same beam direction 450 will be used to receive PRSs from these base stations 420.

Based on the PRS configuration determined by location server 430, base station 420 transmits PRSs on the configured time and frequency resources. The UE410 receives PRSs on the configured time and frequency resources by using Rx beamforming.

Fig. 6 illustrates a flow diagram of an example method 600, according to some example embodiments of the present disclosure. The method 600 may be implemented by the UE410 as shown in fig. 4. For discussion purposes, the method 600 will be described with reference to fig. 4.

At block 605, the UE410 receives an indication from the location server 420 indicating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by the set 440 of neighboring base stations. As described above, in some example embodiments, the indication may be received from location server 430 via the serving cell in a PrivideAssistanceData message using LPP.

At block 610, the UE410 determines a beam direction 450 for receiving the set of positioning reference signals. The beam direction may be determined by beam scanning during PRS reception. The UE410 may determine the beam direction using any suitable beam training method that already exists or will be developed in the future.

In some example embodiments, Rx beamforming may be triggered under some conditions. For example, if the UE410 is located outside of the group 440, Rx beamforming would be preferred. An omni-directional antenna may be better if the UE410 is located inside the group 440, because in this case the UE410 cannot receive a set of PRSs at one time instance in one beam direction.

The UE410 may determine a position relative to a set 440 of neighboring base stations 420 by measuring received signal strengths of a set of PRSs from the base stations 420. For example, the received signal strength may include a signal to noise ratio (SNR). If the received signal strength of the PRS is below a threshold strength, then the UE410 may be determined to be outside of the group 440. Rx beamforming is then triggered to facilitate reception of a set of PRSs for high audibility. If the received signal strength of the PRS exceeds a threshold strength, the UE410 will adaptively switch the RX antenna mode from the directional mode to the omni-directional mode to improve the performance of PRS reception, further improving positioning accuracy.

In example embodiments where group IDs are configured for respective groups of neighboring base stations, UE410 may determine the grouping of base stations based on the group IDs. For example, UE410 may receive a group ID for group 440 of neighboring base stations from location server 430. Based on the group ID, the UE410 may determine that one beam direction is to be used for detecting or receiving a set of PRSs.

To reduce the overhead of beam scanning, the UE410 only needs to perform one beam scan for each group of PRSs. In example embodiments where a group ID is indicated to the UE410, the UE410 may know the relationship between the group 440 and time domain resources (such as transmission occasions) to avoid repeating the beam scanning. The configuration of the group ID may save energy at the UE410 by avoiding repeated Rx beam scanning procedures.

Fig. 7 illustrates an example use of a group ID in accordance with some example embodiments of the present disclosure.

As shown, the UE410 receives PRSs from group #1 in the same beam direction 450-1 at time occasion 705 and time occasion 710. UE410 receives PRS from group #2 in beam direction 450-2 at time occasion 715.

Still referring to fig. 6, at block 615, the UE410 receives the set of positioning reference signals in the beam direction 450 on a time domain resource and a set of frequency domain resources.

Fig. 8 illustrates a flow diagram of an example method 800 in accordance with some example embodiments of the present disclosure. Method 800 may be implemented by one of base stations 420 as shown in fig. 4. For discussion purposes, the method 800 will be described with reference to fig. 4.

At block 805, the base station 420 receives an indication from the location server 420 indicating at least time and frequency domain resources for transmitting PRSs. In some example embodiments, the indication may be received from location server 430 using LPPa or any other suitable protocol.

In some example embodiments, the indicated time domain resource may be one of at least one time domain resource allocated by the location server 430 for a set of positioning reference signals to be transmitted by the set of neighboring base stations 440. The indicated frequency domain resources may be frequency domain resources of a set of frequency domain resources allocated by the location server 430 for the group 440 of neighboring base stations.

In some example embodiments, the indication may indicate to the base station 420 the time and frequency domain resources allocated for the entire group 440. The indication may indicate other configurations associated with the base station 420.

At block 810, the base station 420 transmits PRSs on time and frequency domain resources.

In some example embodiments, base station 420 may receive an indication of a group ID for group 440 of neighboring base stations from location server 430. The indication may also be received by using LPPa or any other suitable protocol.

In some demonstrative embodiments, base station 420 may transmit geographic information, such as its geographic coordinates, to location server 430. Thus, location server 430 may determine which base stations may be clustered into groups 440 based on the geographic locations of the various base stations 420.

All of the operations and features described above with reference to fig. 4-7 are equally applicable to method 800 and have similar effects. Details may be omitted for simplicity.

Fig. 9 shows an example signaling flow 900 between location server 430, base station 420 (e.g., a gNB), and UE410, according to some example embodiments of the present disclosure.

In flow 900, base station 420 provides (905) the geographic coordinates to location server 430. Location server 430 determines (910) a PRS packet and a PRS resource configuration. Location server 430 indicates (915) the PRS configuration to the corresponding group of base stations 420. Location server 430 also indicates (920) a PRS configuration to UE 410. The base station 420 performs (925) PRS transmission using the PRS resource configuration. The UE410 performs (930) PRS reception accordingly.

Fig. 10 shows an example scenario 1000 of packet-based PRS transmissions in accordance with some example embodiments of the present disclosure.

As shown, three neighboring base stations 420-1, 420-2, and 420-3 (labeled as gNB #1, gNB #2, gNB #3) form a group 440-1 (labeled as group # 1). Three neighboring base stations 420-4, 420-5, and 420-6 (labeled gNB #4, gNB #5, gNB #6) for another group 440-2 (labeled group # 2). The two groups are assigned to different transmit

occasions

1005 and 1010. PRSs of group #1 (gbb #1, gbb #2, gbb #3) are transmitted simultaneously on transmission occasion 1005, and PRSs of group #2 (gbb #4, gbb #5, gbb #6) are also transmitted simultaneously on transmission occasion 1010. The PRSs for base stations 410 in a group 440 are transmitted on different frequencies, such as

subcarriers

1015, 1020, and 1025.

In this scenario 1000, the UE410 is outside of the groups 440-1 and 440-2. Accordingly, Rx beamforming is triggered at the UE 410. The UE410 may receive one set of PRSs at one transmission occasion 1005 using one beam direction 450-1 and another set of PRSs at another transmission occasion 1010 using another beam direction 450-2.

Fig. 11 shows an example scenario 1100 of packet-based PRS transmissions in accordance with some other example embodiments of the present disclosure.

In scenario 1100, the grouping of base stations and PRS mapping for each group is the same as for scenario 1000. For simplicity, further description is omitted. As shown, in this example, UE410 is located within group 440-1. In this case, the UE410 may detect that the received SNR of the PRS is high. UE410 then receives PRSs from group 440-1 at transmission opportunity 1005 using omni-directional antenna in omni-directional pattern 1105.

For the PRS of group 440-2, the UE may still use Rx beamforming in beam direction 450-2 since the UE is outside of group 440-2. For example, the UE410 may determine that the measured SNR of the PRSs from the group 440-2 is below a threshold SNR and may trigger Rx beamforming to improve the audibility and positioning accuracy of the PRSs. Thus, a set of PRSs can be received from the set 440-2 of base stations at one time instance.

A packet-based PRS resource configuration mechanism may be used with the UE410 outside of any group 440 to receive a group of PRSs at a time by using Rx beamforming. This mechanism may also be used in the case where the UE410 is located within a group 440 of base stations. In this case, the UE410 may switch the antenna pattern from the directional antenna to the omni-directional antenna for PRS reception according to the measured SNR to guarantee PRS reception performance.

Fig. 12 is a simplified block diagram of a device 1200 suitable for implementing embodiments of the present disclosure. As shown in fig. 4, device 1200 may be implemented by location server 430, UE410, or base station 420.

As shown, the device 1200 includes a processor 1210, a memory 1220 coupled to the processor 1210, a communication module 1230 coupled to the processor 1210, and a communication interface (not shown) coupled to the communication module 1230. The memory 1220 stores at least the program 1240. The communication module 1230 is used for bi-directional communication, e.g., via multiple antennas. The communication interface may represent any interface required for communication.

The programs 1240 are assumed to include program instructions that, when executed by the associated processor 1210, enable the apparatus 1200 to operate in accordance with embodiments of the present disclosure, as discussed herein with reference to fig. 4-11. The embodiments herein may be implemented by computer software executable by the processor 1210 of the device 1200, or by hardware, or by a combination of software and hardware. The processor 1210 may be configured to implement various embodiments of the present disclosure.

The memory 1220 may be of any type suitable to the local technology network and may be implemented using any suitable data storage technology, such as non-transitory computer readable storage media, semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. Although only one memory 1220 is shown in device 1200, there may be several physically distinct memory modules in device 1200. Processor 1210 may be of any type suitable to a local technology network, and may include one or more of the following, as non-limiting examples: general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs) and processors based on a multi-core processor architecture. Device 1200 may have multiple processors, such as application specific integrated circuit chips that are time dependent from a clock synchronized to the main processor.

When the device 1200 acts as the location server 430 or as part of the location server 430, the processor 1210 and the communication module 1230 may cooperate to implement the method 500 as described above with reference to fig. 5. When the apparatus 1200 is included as UE410 or as part of UE410, the processor 1210 and the communication module 1230 may cooperate to implement the method 600 as described above with reference to fig. 6. When the apparatus 1200 acts as a base station 420 or as part of a base station 420, the processor 1210 and the communication module 1230 may cooperate to implement the method 800 as described above with reference to fig. 8. All of the operations and features described above with reference to fig. 4-11 are equally applicable to the apparatus 1200 and have similar effects. Details will be omitted for simplicity.

In general, the various embodiments of the 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 the embodiments of the disclosure are illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the blocks, apparatus, systems, techniques or methods 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) that are executed in a device on a target real or virtual processor to perform

methods

500, 600, and 800 as described above with reference to fig. 4-8. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or split between program modules as desired. Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote memory storage media.

Program code for performing the 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 functions/operations specified in the flowchart and/or block diagram are implemented when executed by the processor or controller. The program code may execute entirely on the 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, computer program code or related data may be carried by any suitable carrier for enabling a device, apparatus or processor to perform various processes and operations as described above. Examples of a 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 is 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 a 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), a Digital Versatile Disc (DVD), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are described 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 some cases, multitasking and parallel processing may be advantageous. Also, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the 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 can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the 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.

Various embodiments of these techniques have been described. In addition to or in the alternative to the above, the following embodiments are described. Features described in any of the examples below may be utilized with any of the other examples described herein.

In some aspects, a location server, comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the location server to: determining a set of neighboring base stations based on the geographic location of the base stations; allocating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations; and transmitting an indication indicating the at least one time domain resource and the set of frequency domain resources to a set of neighboring base stations.

In some example embodiments, the location server is caused to determine the set of neighboring base stations by: receiving geographical information about a plurality of base stations from the plurality of base stations; determining that the plurality of base stations are neighboring based on the received geographic information; and clustering the plurality of base stations into a set of neighboring base stations.

In some example embodiments, one of the at least one time domain resource comprises a time occasion of a positioning reference signal in the time domain.

In some example embodiments, the frequency domain resources of the set of frequency domain resources comprise at least one of subcarriers, subbands, and bandwidth portions in the frequency domain.

In some example embodiments, the location server is further caused to: an indication indicating at least one time domain resource and a set of frequency domain resources is sent towards a user equipment.

In some example embodiments, the location server is further caused to: assigning a group identification for a group of neighboring base stations; and transmitting an indication of the group identity to a group of neighboring base stations.

In some example embodiments, the location server is further caused to: an indication of the group identity is sent towards the user equipment.

In some aspects, a user equipment includes: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the user equipment to: receiving, from a location server, an indication indicating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations; determining a beam direction for receiving the set of positioning reference signals; and receiving a set of positioning reference signals in a beam direction on the time domain resources and the set of frequency domain resources.

In some example embodiments, the user equipment is caused to determine the beam direction by: measuring received signal strengths of a set of positioning reference signals; determining whether the received signal strength is below a threshold strength; and determining a beam direction for receiving a set of positioning reference signals in response to determining that the received signal strength is below the threshold strength.

In some example embodiments, the user equipment is further caused to: in response to determining that the received signal strength exceeds the threshold strength, a set of positioning reference signals is received using the omni-directional antenna.

In some example embodiments, the user equipment is further caused to: an indication of a group identification for a group of neighboring base stations is received from a location server.

In some aspects, a base station comprises: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the base station to: receiving an indication indicating at least time and frequency domain resources for transmitting positioning reference signals from a location server; and transmitting the positioning reference signal on the time domain resource and the frequency domain resource.

In some example embodiments, the time domain resources comprise one of at least one time-frequency resource allocated by the location server for a set of positioning reference signals to be transmitted by a set of neighboring base stations, and the frequency domain resources comprise frequency domain resources of a set of frequency domain resources allocated by the location server for a set of positioning reference signals.

In some example embodiments, the base station is further caused to: an indication of a group identification for a group of neighboring base stations is received from a location server.

In some example embodiments, the base station is further caused to: sending geographical information about the base station to a location server.

In some aspects, a method comprises: determining, by a location server, a set of neighboring base stations based on the geographic locations of the base stations; allocating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations; and transmitting an indication indicating the at least one time domain resource and the set of frequency domain resources to a set of neighboring base stations.

In some example embodiments, determining a set of neighboring base stations comprises: receiving geographical information about a plurality of base stations from the plurality of base stations; determining that the plurality of base stations are neighboring based on the received geographic information; and clustering the plurality of base stations into a set of neighboring base stations.

In some example embodiments, the method further comprises: an indication indicating at least one time domain resource and a set of frequency domain resources is sent towards a user equipment.

In some example embodiments, the method further comprises: assigning a group identification for a group of neighboring base stations; and transmitting an indication of the group identity to a group of neighboring base stations.

In some example embodiments, the method further comprises: an indication of the group identity is sent towards the user equipment.

In some aspects, a method comprises: receiving, by a user equipment from a location server, an indication indicating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals, the set of positioning reference signals to be transmitted by a set of neighboring base stations; determining a beam direction for receiving a set of positioning reference signals; and receiving a set of positioning reference signals in a beam direction on the time domain resources and the set of frequency domain resources.

In some example embodiments, determining the beam direction comprises: measuring received signal strengths of a set of positioning reference signals; determining whether the received signal strength is below a threshold strength; and determining a beam direction for receiving a set of positioning reference signals in response to determining that the received signal strength is below the threshold strength.

In some example embodiments, the method further comprises: in response to determining that the received signal strength exceeds the threshold strength, a set of positioning reference signals is received using the omni-directional antenna.

In some example embodiments, the method further comprises: an indication of a group identification for a group of neighboring base stations is received from a location server.

In some example embodiments, a method comprises: receiving, by a base station from a location server, an indication indicating at least time and frequency domain resources for transmitting positioning reference signals; and transmitting the positioning reference signal on the time domain resource and the frequency domain resource.

In some example embodiments, the time domain resource comprises one of at least one time domain resource allocated by the location server for a set of positioning reference signals to be transmitted by a set of neighboring base stations, and the frequency domain resource comprises a frequency domain resource of a set of frequency domain resources allocated by the location server for the set of positioning reference signals.

In some example embodiments, the method further comprises: sending geographical information about the base station to a location server.

In some aspects, an apparatus comprises: means for determining, by a location server, a set of neighboring base stations based on the geographic locations of the base stations; means for allocating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations; and means for transmitting an indication indicating the at least one time domain resource and the set of frequency domain resources to a set of neighboring base stations.

In some example embodiments, the means for determining a set of neighboring base stations comprises: means for receiving geographic information about a plurality of base stations from the plurality of base stations; means for determining that a plurality of base stations are nearby based on the received geographic information; and means for clustering the plurality of base stations into a set of neighboring base stations.

In some example embodiments, the apparatus further comprises: means for transmitting, towards a user equipment, an indication indicating at least one time domain resource and a set of frequency domain resources.

In some example embodiments, the apparatus further comprises: means for assigning a group identification for a group of neighboring base stations; and means for transmitting an indication of the group identity to a group of neighboring base stations.

In some example embodiments, the apparatus further comprises: means for sending an indication of the group identity towards the user equipment.

In some aspects, an apparatus comprises: means for receiving, by a user equipment from a location server, an indication indicating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations; means for determining a beam direction for receiving a set of positioning reference signals; and means for receiving a set of positioning reference signals in a beam direction on the time domain resources and the set of frequency domain resources by the user.

In some example embodiments, the means for determining the beam direction comprises: means for measuring received signal strengths of a set of positioning reference signals; means for determining whether the received signal strength is below a threshold strength; and means for determining a beam direction for receiving a set of positioning reference signals in response to determining that the received signal strength is below a threshold strength.

In some example embodiments, the apparatus further comprises: means for receiving a set of positioning reference signals using the omni-directional antenna in response to determining that the received signal strength exceeds the threshold strength.

In some example embodiments, the apparatus further comprises: means for receiving an indication of a group identity for a group of neighboring base stations from a location server.

In some example embodiments, an apparatus comprises: means for receiving, by a base station from a location server, an indication indicating at least time and frequency domain resources for transmitting positioning reference signals; and means for transmitting the positioning reference signal on the time domain resources and the frequency domain resources.

In some example embodiments, the apparatus further comprises: means for receiving an indication of a group identification for a group of neighboring base stations from a location server.

In some example embodiments, the apparatus further comprises: means for sending geographical information about the base station to a location server.

In some aspects, a computer-readable storage medium includes program instructions stored thereon that, when executed by a processor of a device, cause the device to perform a method according to some example embodiments of the present disclosure.

Claims

1. A location server, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the location server to:

determining a set of neighboring base stations based on the geographic location of the base stations;

allocating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by the set of neighboring base stations; and

transmitting an indication indicating the at least one time domain resource and the set of frequency domain resources to the set of neighboring base stations.

2. The location server of claim 1, wherein the location server is caused to determine the set of neighboring base stations by:

receiving, from a plurality of base stations, geographical information about the plurality of base stations;

determining that the plurality of base stations are neighboring based on the received geographic information; and

clustering the plurality of base stations into the set of neighboring base stations.

3. The location server of claim 1, wherein one of the at least one time domain resource comprises a time occasion of a positioning reference signal in the time domain.

4. The location server of claim 1, wherein a frequency domain resource of the set of frequency domain resources comprises at least one of a subcarrier, a subband, and a bandwidth portion in a frequency domain.

5. The location server of claim 1, wherein the location server is further caused to:

transmitting, towards a user equipment, an indication indicating the at least one time domain resource and the set of frequency domain resources.

6. The location server of claim 1, wherein the location server is further caused to:

assigning a group identification for the set of neighboring base stations; and

transmitting an indication of the group identification to the group of neighboring base stations.

7. The location server of claim 6, wherein the location server is further caused to:

sending an indication of the group identity towards a user equipment.

8. A user equipment, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the user equipment to:

receiving, from a location server, an indication indicating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations;

determining a beam direction for receiving the set of positioning reference signals; and

receiving the set of positioning reference signals in the beam direction on the time domain resources and the set of frequency domain resources.

9. The user equipment of claim 8, wherein the user equipment is caused to determine the beam direction by:

measuring received signal strengths of the set of positioning reference signals;

determining whether the received signal strength is below a threshold strength; and

determining the beam direction for receiving the set of positioning reference signals in response to determining that the received signal strength is below the threshold strength.

10. The user equipment of claim 9, wherein the user equipment is further caused to:

receiving the set of positioning reference signals using an omni-directional antenna in response to determining that the received signal strength exceeds the threshold strength.

11. The user equipment of claim 8, wherein the user equipment is further caused to:

receiving, from the location server, an indication of a group identification for the group of neighboring base stations.

12. A base station, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the base station to:

receiving an indication indicating at least time and frequency domain resources for transmitting positioning reference signals from a location server; and

transmitting the positioning reference signal on the time domain resources and the frequency domain resources.

13. The base station of claim 12, wherein the time domain resource comprises one of at least one time-frequency resource allocated by the location server for a set of positioning reference signals to be transmitted by a set of neighboring base stations, and the frequency domain resource comprises a frequency domain resource of a set of frequency domain resources allocated by the location server for the set of positioning reference signals.

14. The base station of claim 12, wherein the base station is further caused to:

15. The base station of claim 12, wherein the base station is further caused to:

sending geographic information about the base station to the location server.

16. A method, comprising:

determining, by a location server, a set of neighboring base stations based on the geographic locations of the base stations;

17. The method of claim 16, wherein determining the set of neighboring base stations comprises:

18. The method of claim 16, wherein one of the at least one time domain resource comprises a time occasion of a positioning reference signal in the time domain.

19. The method of claim 16, wherein a frequency domain resource of the set of frequency domain resources comprises at least one of a subcarrier, a subband, and a bandwidth portion in a frequency domain.

20. The method of claim 16, further comprising:

21. The method of claim 16, further comprising:

assigning a group identification for the set of neighboring base stations; and

22. The method of claim 16, further comprising:

sending an indication of the group identity towards a user equipment.

23. A method, comprising:

receiving, by a user equipment from a location server, an indication indicating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations;

24. The method of claim 23, wherein determining the beam direction comprises:

25. The method of claim 24, further comprising:

26. The method of claim 23, further comprising:

27. A method, comprising:

receiving, by a base station from a location server, an indication indicating at least time and frequency domain resources for transmitting positioning reference signals; and

28. The method of claim 27, wherein the time domain resource comprises one of at least one time domain resource allocated by the location server for a set of positioning reference signals to be transmitted by a set of neighboring base stations, and the frequency domain resource comprises a frequency domain resource of a set of frequency domain resources allocated by the location server for the set of positioning reference signals.

29. The method of claim 27, further comprising:

30. The method of claim 27, further comprising:

sending geographic information about the base station to the location server.

31. An apparatus, comprising:

means for determining, by a location server, a set of neighboring base stations based on the geographic locations of the base stations;

means for allocating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by the set of neighboring base stations; and

means for transmitting an indication indicating the at least one time domain resource and the set of frequency domain resources to the set of neighboring base stations.

32. An apparatus, comprising:

means for receiving, by a user equipment, an indication from a location server indicating at least one time domain resource and a set of frequency domain resources for a set of positioning reference signals to be transmitted by a set of neighboring base stations;

means for determining a beam direction for receiving the set of positioning reference signals; and

means for receiving the set of positioning reference signals in the beam direction on the time domain resources and the set of frequency domain resources.

33. An apparatus, comprising:

means for receiving, by a base station from a location server, an indication indicating time domain resources and frequency domain resources for transmitting positioning reference signals; and

means for transmitting the positioning reference signal on the time domain resources and the frequency domain resources.

34. A computer readable storage medium comprising program instructions stored thereon which, when executed by a processor of an apparatus, cause the apparatus to perform the method of any of claims 16 to 22.

35. A computer readable storage medium comprising program instructions stored thereon which, when executed by a processor of an apparatus, cause the apparatus to perform the method of any of claims 23 to 26.

36. A computer readable storage medium comprising program instructions stored thereon which, when executed by a processor of an apparatus, cause the apparatus to perform the method of any of claims 27 to 30.