阅读说明：本技术 定位参考信号的延迟展宽和平均延迟准共置源 (Delay spread and average delay quasi-co-located source for positioning reference signals ) 是由 A·马诺拉科斯 S·阿卡拉卡兰 G·R·欧普斯奥格 J·B·索里阿加 骆涛 于 2019-09-25 设计创作，主要内容包括：所公开的是用于接收用于定位估计的参考射频(RF)信号的技术。在一个方面中,接收机设备在无线信道上从发射点接收参考RF信号,从定位实体接收对所述参考RF信号充当由所述接收机设备在所述无线信道上从所述发射点接收的定位参考RF信号的准共置(QCL)类型的源的指示,基于所述QCL类型测量所述参考RF信号的平均延迟、延迟展宽或者所述平均延迟和所述延迟展宽两者,在所述无线信道上从所述发射点接收定位参考RF信号,以及,基于所述参考RF信号的所测量的平均延迟、所述延迟展宽或者所述平均延迟和所述延迟展宽两者识别所述定位参考RF信号的到达时间(ToA)。(Disclosed are techniques for receiving reference Radio Frequency (RF) signals for position estimation. In one aspect, a receiver device receives a reference RF signal from a transmission point over a wireless channel, receives an indication from a positioning entity that the reference RF signal serves as a source of a quasi-co-location (QCL) type for a positioning reference RF signal received by the receiver device from the transmission point over the wireless channel, measures an average delay, a delay spread, or both the average delay and the delay spread of the reference RF signal based on the QCL type, receives a positioning reference RF signal from the transmission point over the wireless channel, and identifies a time of arrival (ToA) of the positioning reference RF signal based on the measured average delay, the delay spread, or both the average delay and the delay spread of the reference RF signal.)

1. A method of wireless communication performed by a receiver device, comprising:

receiving a reference RF signal from a transmission point over a wireless channel;

receiving, from a positioning entity over the wireless channel, an indication that the reference RF signal serves as a quasi-co-location (QCL) type source of positioning reference RF signals received by the receiver device from the transmission point;

measuring an average delay, a delay spread, or both the average delay and the delay spread of the reference RF signal based on the QCL type;

receiving a positioning reference RF signal from the transmission point over the wireless channel; and

identifying a time of arrival (ToA) of the positioning reference RF signal based on the measured average delay, the delay spread, or both the average delay and the delay spread of the reference RF signal.

2. The method of claim 1, further comprising:

calculating a channel energy response of the positioning reference RF signal; and

identifying the ToA of the positioning reference RF signal based on a peak in the channel energy response of the positioning reference RF signal occurring within a time period defined by the average delay, the delay spread, or both the average delay and the delay spread.

3. The method of claim 1, wherein the average delay comprises an average of a first time at which a first channel tap of the reference RF signal is received and a second time at which a last channel tap of the reference RF signal is received.

4. The method of claim 1, wherein the delay spread comprises an amount of time from a first time at which a first channel tap of the reference RF signal is received to a second time at which a last channel tap of the reference RF signal is received.

5. The method of claim 1, wherein the reference RF signal comprises a Synchronization Signal Block (SSB).

6. The method of claim 1, wherein the positioning reference RF signals comprise Positioning Reference Signals (PRS), Navigation Reference Signals (NRS), Transmitter Reference Signals (TRS), cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), Primary Synchronization Signals (PSS), or Secondary Synchronization Signals (SSS).

7. The method of claim 1, wherein the receiver device is configured with a plurality of positioning reference RF signal resources from a plurality of cells, wherein each positioning reference RF signal resource is carried in a same Orthogonal Frequency Division Multiplexing (OFDM) symbol and has a different cyclic shift, the method further comprising:

for each positioning reference RF signal resource, measuring a delay spread of a reference RF signal transmitted on the positioning reference RF signal resource;

for each cell, determining a time period defined by the delay spread of the reference RF signal transmitted on the positioning reference RF signal resource of the cell; and

for each cell, shifting the time period based on the cyclic shift of the positioning reference RF signal resource of the cell.

8. The method of claim 7, further comprising:

receiving a positioning reference RF signal from the transmission point through each of the plurality of positioning reference RF signal resources,

wherein the sequence for each positioning reference RF signal is a Zadoff-Chu sequence, and wherein each cell shifts the Zadoff-Chu sequence with the corresponding cyclic shift.

9. The method of claim 1, further comprising:

receiving, at the receiver device, a second reference RF signal from a second transmission point over a second wireless channel;

receiving, at the receiver device from the transmission point over the second wireless channel, an indication of the second reference RF signal serving as a source of a second QCL type for positioning reference RF signals received by the receiver device from the second transmission point;

measuring, by the receiver device, a second average delay, a second delay spread, or both the second average delay and the second delay spread of the second reference RF signal based on the second QCL type;

receiving, at the receiver device, a second positioning reference RF signal from the second transmission point over the second wireless channel; and

identifying, by the receiver device, a second ToA of the second positioning reference RF signal based on the second average delay, the second delay spread, or both the second average delay and the second delay spread of the second reference RF signal.

10. The method of claim 9, further comprising:

performing a positioning operation based on the ToA of the positioning reference RF signal and the second ToA of the second positioning reference RF signal,

wherein the positioning operation comprises calculating a Reference Signal Timing Difference (RSTD) between the ToA and the second ToA.

11. The method of claim 10, wherein the receiver device reports the RSTD to the positioning entity.

12. The method of claim 1, wherein the QCL type indicates that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

13. The method of claim 12, wherein, based on the QCL type indicating that the reference RF signal and the positioning reference RF signal have both the same average delay and the same delay spread, the transmission point transmits the positioning reference RF signal using a higher comb pattern than if the QCL type indicated that the reference RF signal and the positioning reference RF signal have only the same average delay or only the same delay spread.

14. The method of claim 12, wherein the transmission point transmits the positioning reference RF signal using a higher comb than a comb that can be used if the QCL type does not indicate that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

15. The method of claim 1, wherein the receiver device comprises a User Equipment (UE) and the transmission point comprises a base station.

16. The method of claim 1, wherein the receiver device comprises a base station and the transmission point comprises a User Equipment (UE).

17. A method of wireless communication performed by a transmission point, comprising:

transmitting a reference RF signal to a receiver device over a wireless channel;

transmitting, to the receiver device, an indication on the wireless channel that the reference RF signal serves as a quasi-co-location (QCL) type source of positioning reference RF signals received by the receiver device from the transmission point; and

transmitting a positioning reference RF signal to the receiver device over the wireless channel according to the QCL type, wherein the QCL type indicates that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

18. The method of claim 17, further comprising:

receiving, from the receiver device, a time of arrival (ToA) of the positioning reference RF signal calculated based on a measured average delay, a measured delay spread, or both the measured average delay and the measured delay spread of the reference RF signal.

19. The method of claim 17, wherein, based on the QCL type indicating that the reference RF signal and the positioning reference RF signal have both the same average delay and the same delay spread, the transmission point transmits the positioning reference RF signal using a higher comb pattern than if the QCL type indicated that the reference RF signal and the positioning reference RF signal have only the same average delay or only the same delay spread.

20. The method of claim 17, wherein the transmission point transmits the positioning reference RF signal using a higher comb than a comb that can be used if the QCL type does not indicate that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

21. The method of claim 17, wherein the receiver device comprises a User Equipment (UE) and the transmission point comprises a base station.

22. The method of claim 17, wherein the receiver device comprises a base station and the transmission point comprises a User Equipment (UE).

23. An apparatus for wireless communication, comprising:

at least one receiver of a receiver device configured to:

receiving a reference RF signal from a transmission point over a wireless channel; and

receiving, from the transmission point, an indication over the wireless channel that the reference RF signal serves as a quasi-co-location (QCL) type source of positioning reference RF signals received by the receiver device from the transmission point; and

at least one processor of the receiver device configured to perform operations comprising:

measuring an average delay, a delay spread, or both the average delay and the delay spread of the source reference RF signal based on the QCL type,

wherein the at least one receiver is further configured to receive a positioning reference RF signal from the transmission point over the wireless channel, and

wherein the at least one processor is further configured to identify a time of arrival (ToA) of the positioning reference RF signal based on the measured average delay, the delay spread, or both the average delay and the delay spread of the reference RF signal.

24. The apparatus of claim 23, wherein the at least one processor is further configured to:

calculating a channel energy response of the positioning reference RF signal; and

identifying the ToA of the positioning reference RF signal based on a peak in the channel energy response of the positioning reference RF signal occurring within a time period defined by the average delay, the delay spread, or both the average delay and the delay spread.

25. The apparatus of claim 23, wherein the QCL type indicates that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

26. The apparatus of claim 25, wherein, based on the QCL type indicating that the reference RF signal and the positioning reference RF signal have both the same average delay and the same delay spread, the transmission point transmits the positioning reference RF signal using a higher comb pattern than if the QCL type indicated that the reference RF signal and the positioning reference RF signal have only the same average delay or only the same delay spread.

27. The apparatus of claim 25, wherein the transmission point transmits the positioning reference RF signal using a higher comb than a comb that can be used if the QCL does not indicate that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

28. An apparatus for wireless communication, comprising:

a transmitter of a transmission point configured to perform the following operations:

transmitting a reference RF signal to a receiver device over a wireless channel;

transmitting, to the receiver device, an indication on the wireless channel that the reference RF signal serves as a quasi-co-location (QCL) type source of positioning reference RF signals received by the receiver device from the transmission point; and

transmitting a positioning reference RF signal to the receiver device over the wireless channel according to the QCL type, wherein the QCL type indicates that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

29. The apparatus of claim 28, wherein, based on the QCL type indicating that the reference RF signal and the positioning reference RF signal have both the same average delay and the same delay spread, the transmission point transmits the positioning reference RF signal using a higher comb pattern than if the QCL type indicated that the reference RF signal and the positioning reference RF signal have only the same average delay or only the same delay spread.

30. The apparatus of claim 28, wherein the transmission point transmits the positioning reference RF signal using a higher comb than a comb that can be used if the QCL type does not indicate that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

Technical Field

Various aspects described herein relate generally to wireless communication systems, and more specifically to positioning a quasi-co-located source of delay spread and average delay for reference signals.

Background

Wireless communication systems have evolved through various generations including first generation analog wireless telephone service (1G), second generation (2G) digital wireless telephone service (including transitional phase 2.5G and 2.75G networks), third generation (3G) high speed data, internet-enabled wireless service, and fourth generation (4G) service (e.g., Long Term Evolution (LTE) or WiMax). There are currently many different types of wireless communication systems in use, including cellular and Personal Communication Services (PCS) systems. Examples of known cellular systems include the cellular analog Advanced Mobile Phone System (AMPS) and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), global system for mobile access (GSM) variants of TDMA, and the like.

The fifth generation (5G) mobile standard specifically requires higher data transfer speeds, a greater number of connections, and better coverage. According to the next generation mobile network alliance, the 5G standard is designed to provide data rates of tens of megabits per second to each of tens of thousands of users, and 1 gigabit per second to tens of workers in an office building. To support large-scale sensor deployments, hundreds of thousands of simultaneous connections should be supported. Therefore, the spectral efficiency of 5G mobile communication should be greatly enhanced compared to the current 4G standard. Furthermore, the signaling efficiency should be enhanced and the latency should be reduced considerably compared to the current standard.

To support location estimation in terrestrial wireless networks, mobile devices may be configured to measure and report observed time difference of arrival (OTDOA) or Reference Signal Timing Difference (RSTD) between reference Radio Frequency (RF) signals received from two or more network nodes, e.g., different base stations or different transmission points (e.g., antennas) belonging to the same base station.

Disclosure of Invention

The following presents a simplified summary in relation to one or more aspects disclosed herein. Thus, the following summary should not be considered a broad summary relating to all contemplated aspects, nor should the following summary be considered to identify key or critical elements relating to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the sole purpose of the following summary is to present certain concepts related to one or more aspects of the mechanisms disclosed herein in a simplified form as a prelude to the more detailed description that is presented below.

In one aspect, a method for receiving a reference RF signal for position estimation includes: receiving, at a receiver device, a reference RF signal from a transmission point over a wireless channel; receiving, at the receiver device, an indication from a positioning entity on the wireless channel that the reference RF signal serves as a source of a quasi-co-location (QCL) type of positioning reference RF signals received by the receiver device from the transmission point; measuring, by the receiver device, an average delay, a delay spread, or both the average delay and the delay spread of the source reference RF signal based on the QCL type; receiving, at the receiver device, a positioning reference RF signal from the transmission point over the wireless channel; and identifying, by the receiver device, a time of arrival (ToA) of the positioning reference RF signal based on the measured average delay, the delay spread, or both of the reference RF signal.

In one aspect, a method of wireless communication performed by a transmission point includes: transmitting a reference RF signal to a receiver device over a wireless channel; transmitting, to the receiver device, an indication on the wireless channel that the reference RF signal serves as a source of QCL types for positioning reference RF signals received by the receiver device from the transmission point; and transmitting a positioning reference RF signal to the receiver device over the wireless channel according to the QCL type, wherein the QCL type indicates that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

In one aspect, an apparatus for wireless communication comprises: at least one receiver of a receiver device configured to: receiving a reference RF signal from a transmission point over a wireless channel; and receiving, from a positioning entity over the wireless channel, an indication that the reference RF signal serves as a source of QCL type for positioning reference RF signals received by the receiver device from the transmission point; and at least one processor of the receiver device configured to perform the following operations: measuring an average delay, a delay spread, or both the average delay and the delay spread of the source reference RF signal based on the QCL type, wherein the at least one receiver is further configured to receive a positioning reference RF signal from the transmission point over the wireless channel, and wherein the at least one processor is further configured to identify a ToA of the positioning reference RF signal based on the measured average delay, the delay spread, or both the average delay and the delay spread of the reference RF signal.

In one aspect, an apparatus for wireless communication comprises: a transmitter of a transmission point configured to perform the following operations: transmitting a reference RF signal to a receiver device over a wireless channel; transmitting, to the receiver device, an indication on the wireless channel that the reference RF signal serves as a source of QCL types for positioning reference RF signals received by the receiver device from the transmission point; and transmitting, to the receiver device, a positioning reference RF signal over the wireless channel according to the QCL type, wherein the QCL type indicates that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

In one aspect, an apparatus for wireless communication comprises: means for receiving, at a receiver device, a reference RF signal from a transmission point over a wireless channel; means for receiving, at the receiver device, an indication from a positioning entity on the wireless channel that the reference RF signal serves as a source of QCL types for positioning reference RF signals received by the receiver device from the transmission points; means for measuring, by the receiver device, an average delay, a delay spread, or both the average delay and the delay spread of the source reference RF signal based on the QCL type; means for receiving, at the receiver device, a positioning reference RF signal from the transmission point over the wireless channel; and means for identifying, by the receiver device, a ToA of the positioning reference RF signal based on the measured average delay, the delay spread, or both the average delay and the delay spread of the reference RF signal.

In one aspect, an apparatus for wireless communication comprises: means for transmitting a reference RF signal to a receiver device over a wireless channel; means for transmitting, to the receiver device, an indication on the wireless channel that the reference RF signal serves as a source of QCL types for positioning reference RF signals received by the receiver device from the transmission point; and means for transmitting a positioning reference RF signal to the receiver device over the wireless channel according to the QCL type, wherein the QCL type indicates that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

In one aspect, a non-transitory computer-readable medium storing computer-executable instructions for wireless communications includes computer-executable instructions comprising: at least one instruction instructing a receiver device to receive a reference RF signal from a transmission point over a wireless channel; at least one instruction to instruct the receiver device to receive, from a positioning entity over the wireless channel, an indication that the reference RF signal serves as a source of QCL types for positioning reference RF signals received by the receiver device from the transmission point; at least one instruction to instruct the receiver device to measure an average delay, a delay spread, or both the average delay and the delay spread of the source reference RF signal based on the QCL type; at least one instruction instructing the receiver device to receive a positioning reference RF signal from the transmission point over the wireless channel; and at least one instruction instructing the receiver device to identify a ToA of the positioning reference RF signal based on the measured average delay, the delay spread, or both the average delay and the delay spread of the reference RF signal.

In one aspect, a non-transitory computer-readable medium storing computer-executable instructions for wireless communications includes computer-executable instructions comprising: transmitting a reference RF signal to a receiver device over a wireless channel; transmitting, to the receiver device, an indication on the wireless channel that the reference RF signal serves as a source of QCL types for positioning reference RF signals received by the receiver device from the transmission point; and transmitting a positioning reference RF signal to the receiver device over the wireless channel according to the QCL type, wherein the QCL type indicates that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

Other objects and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the drawings and detailed description.

Drawings

A more complete appreciation of the various aspects described herein and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings which are given by way of illustration only and not limitation, and wherein:

fig. 1 illustrates an example wireless communication system in accordance with aspects of the present disclosure.

Fig. 2A and 2B illustrate example wireless network structures in accordance with aspects of the present disclosure.

Fig. 3 illustrates an example base station and an example UE in an access network in accordance with aspects of the present disclosure.

Fig. 4 is a diagram illustrating an exemplary technique for determining a location of a mobile device using information obtained from multiple base stations in accordance with an aspect of the disclosure.

Fig. 5A and 5B illustrate graphs of example Channel Energy Responses (CER) in accordance with aspects of the present disclosure.

Fig. 6 is a graph comparing a Cumulative Distribution Function (CDF) to a fully initialized range error across all UEs of a particular sampling set, in accordance with aspects of the present disclosure.

Fig. 7 through 8B are graphs of example CER estimates, in accordance with aspects of the present disclosure.

Fig. 9 illustrates how cyclic shifts change the average delay of a wireless channel, in accordance with aspects of the present disclosure.

Fig. 10 and 11 illustrate example methods for wireless communication, in accordance with aspects of the present disclosure.

Detailed Description

Various aspects described herein relate generally to wireless communication systems, and more specifically to delay spread and average delay quasi-co-located sources for positioning reference signals in 5G NR and associated transmission parameters. These and other aspects are disclosed in the following description and related drawings to illustrate specific examples related to the exemplary aspects. From reading the present disclosure, alternative aspects will be apparent to persons skilled in the relevant art, and may be constructed and practiced without departing from the scope or spirit of the present disclosure. Additionally, well-known elements will not be described in detail or may be omitted so as not to obscure the relevant details of the aspects disclosed herein.

The terms "exemplary" and/or "example" are used herein to mean "serving as an example, instance, or illustration. Any aspect described herein as "exemplary" and/or "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term "aspects of the disclosure" does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation.

The terminology used herein describes particular aspects only and should not be interpreted as limiting any aspect disclosed herein. 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 by those within the art that the terms "comprises," "comprising," "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Those of skill in the art would understand that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the following description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the particular application, desired design, corresponding technology, and so forth.

Further, many aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be recognized that various actions described herein can be performed by specific circuits (e.g., Application Specific Integrated Circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of both. Additionally, the sequences of actions described herein can be considered to be embodied entirely within any form of non-transitory computer-readable storage medium having stored therein a corresponding set of computer instructions that upon execution would cause or instruct a processor of an associated device to perform the functions described herein. Thus, the various aspects of the disclosure may be embodied in many different forms, all of which have been contemplated to be within the scope of the claimed subject matter. Additionally, for each of the aspects described herein, any such aspect in a corresponding form may be described herein as, for example, "a logic unit configured to" perform the described action.

As used herein, unless otherwise indicated, the terms "user equipment" (UE) and "base station" are not intended to be dedicated to or limited to any particular Radio Access Technology (RAT). In general, a UE may be any wireless communication device (e.g., a mobile phone, router, tablet computer, laptop computer, tracking device, wearable device (e.g., smart watch, glasses, Augmented Reality (AR)/Virtual Reality (VR) headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.), internet of things (IoT) device, etc.) used by a user to communicate over a wireless communication network. The UE may be mobile or may be fixed (e.g., at a particular time) and may communicate with a Radio Access Network (RAN). As used herein, the term "UE" may be interchangeably referred to as an "access terminal" or "AT," "client device," "wireless device," "subscriber terminal," "subscriber station," "user terminal" or UT, "mobile terminal," "mobile station," or variations thereof. In general terms, a UE may communicate with a core network via a RAN, and through the core network, the UE may be connected with an external network such as the internet or with other UEs. Of course, other mechanisms of connecting to the core network and/or the internet are possible for the UE, such as through a wired access network, a Wireless Local Area Network (WLAN) network (e.g., IEEE 802.11 based, etc.), and so forth.

Depending on the network in which it is deployed, a base station, when communicating with a UE, may operate according to one of several RATs and may alternatively be referred to as an Access Point (AP), a network node, a node B, an evolved node B (enb), a New Radio (NR) node B (also referred to as a gNB or g-node B), or the like. In addition, in some systems, the base station may simply provide edge node signaling functionality, while in other systems it may provide additional control and/or network management functionality. The communication link through which a UE can transmit signals to a base station is called an Uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). The communication link through which a base station may transmit signals to a UE is called a Downlink (DL) or forward link channel (e.g., paging channel, control channel, broadcast channel, forward traffic channel, etc.). As used herein, the term Traffic Channel (TCH) may refer to either a UL/reverse or DL/forward traffic channel.

In accordance with various aspects, fig. 1 illustrates an example wireless communication system 100. The wireless communication system 100, which may also be referred to as a Wireless Wide Area Network (WWAN), may include various base stations 102 and various UEs 104. The base station 102 may include a macrocell base station (high power cellular base station) and/or a small cell base station (low power cellular base station). In one aspect, the macrocell base station may include an eNB (where the wireless communication system 100 corresponds to an LTE network) or a gNB (where the wireless communication system 100 corresponds to a 5G network) or a combination of both, and the small cell base station may include a femtocell, a picocell, a microcell, or the like.

The base stations 102 may collectively form a RAN and interface with a core network 170 (e.g., an Evolved Packet Core (EPC) or Next Generation Core (NGC)) over backhaul links 122 and to one or more location servers 172 over the core network 170. The base station 102 may perform, inter alia, functions related to one or more of transmitting user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, Multimedia Broadcast Multicast Service (MBMS), user and device tracking, RAN Information Management (RIM), paging, positioning, and delivery of alarm messages. Base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC/NGC) through backhaul links 134 (which may be wired or wireless).

The base station 102 may communicate wirelessly with the UE 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. In an aspect, one or more cells may be supported in each coverage area 110 by one base station 102. A "cell" is a logical communication entity used for communication with a base station (e.g., over some frequency resources referred to as carrier frequencies, component carriers, frequency bands, etc.) and may be associated with an identifier (e.g., a Physical Cell Identifier (PCID), a Virtual Cell Identifier (VCID)) for distinguishing cells operating via the same or different carrier frequencies. In some cases, different cells may be configured according to different protocol types (e.g., Machine Type Communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), etc.) that may provide access for different types of UEs. In some cases, the term "cell" may also refer to a geographic coverage area (e.g., a sector) of a base station only when a carrier frequency may be detected and used for communication within a certain portion of geographic coverage area 110.

While the neighboring macrocell base station 102 geographic coverage areas 110 can partially overlap (e.g., in a handover region), some of the geographic coverage areas 110 can substantially overlap with larger geographic coverage areas 110. For example, the small cell base station 102 'may have a coverage area 110' that substantially overlaps with the coverage area 110 of one or more macro cell base stations 102. A network that includes both small cell and macro cell base stations may be referred to as a heterogeneous network. The heterogeneous network may also include home enbs (henbs), which may serve a restricted group called a Closed Subscriber Group (CSG).

The communication link 120 between the base station 102 and the UE 104 may include UL (also referred to as reverse link) transmissions from the UE 104 to the base station 102 and/or Downlink (DL) (also referred to as forward link) transmissions from the base station 102 to the UE 104. The communication link 120 may use MIMO antenna techniques including spatial multiplexing, beamforming, and/or transmit diversity. The communication link 120 may be over one or more carrier frequencies. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than UL).

The wireless communication system 100 may further include a Wireless Local Area Network (WLAN) Access Point (AP)150 that communicates with a WLAN Station (STA)152 via a communication link 154 in an unlicensed spectrum (e.g., 5 GHz). When communicating in the unlicensed spectrum, the WLAN STA 152 and/or WLAN AP 150 may perform a Clear Channel Assessment (CCA) to determine whether a channel is available prior to communicating.

The small cell base station 102' may operate in a licensed and/or unlicensed spectrum. When operating in unlicensed spectrum, the small cell base station 102' may use LTE or 5G technology and use the same 5GHz unlicensed spectrum as used by the WLAN AP 150. Small cell base stations 102' using LTE/5G in unlicensed spectrum may improve coverage and/or increase capacity of the access network. LTE in unlicensed spectrum may be referred to as unlicensed LTE (LTE-U), Licensed Assisted Access (LAA), or MulteFire.

The wireless communication system 100 may further include a millimeter wave (mmW) base station 180 that may operate in mmW frequencies and/or near mmW frequencies when communicating with the UE 182. Extremely High Frequency (EHF) is a part of RF in the electromagnetic spectrum. The EHF has a range of 30GHz to 300GHz and a wavelength between 1 millimeter to 10 millimeters. The radio waves in this frequency band may be referred to as millimeter waves. Near mmW may extend down to a frequency of 3GHz with a wavelength of 100 mm. The ultra-high frequency (SHF) band extends between 3GHz and 30GHz, also known as centimeter waves. Communications using the mmW/near mmW wireless band have high path loss and relatively short range. The mmW base station 180 and the UE 182 may use beamforming (transmit and/or receive) on the mmW communication link 184 to compensate for extremely high path loss and short range. Further, it should be appreciated that in alternative configurations, one or more base stations 102 may also transmit using mmW or near mmW and beamforming. Accordingly, it should be recognized that the foregoing description is merely an example and should not be construed as limiting the various aspects disclosed herein.

Transmit beamforming is a technique for focusing RF signals in a particular direction. Conventionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectionally). By transmit beamforming, the network node determines where (relative to the transmitting network node) a given target device (e.g., UE) is located and projects a stronger downlink RF signal in that particular direction, thus providing a faster (in terms of data rate) and stronger RF signal for the receiving device. To change the direction of the RF signal when transmitting, the network node may control the phase and relative amplitude of the RF signal at each of the one or more transmitters that are broadcasting the RF signal. For example, a network node may use an array of antennas (referred to as a "phased array" or "antenna array") that produce beams of RF waves that may be "steered" to points in different directions, without actually moving the antennas. Specifically, the RF current from the transmitter is fed to the individual antennas with the correct phase relationship so that the radio waves from the individual antennas add together to increase the radiation in the desired direction and cancel out to suppress the radiation in the undesired direction.

In receive beamforming, a receiver uses a receive beam to amplify an RF signal detected on a given channel. For example, the receiver may increase the gain setting of the array of antennas in a particular direction and/or adjust its phase setting to amplify (e.g., to increase the gain level) the RF signals received from that direction. Thus, when it is said that the receiver performs beamforming in a particular direction, this means that the beam gain in that direction is relatively higher than the beam gain in other directions, or that the beam gain in that direction is the highest compared to all other receive beams available to the receiver. This results in a stronger received signal strength (e.g., Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), signal to interference plus noise ratio (SINR), etc.) of the RF signal received from that direction.

An "RF" signal comprises an electromagnetic wave that transports information through the space between a transmitter (e.g., base station 102) and a receiver (e.g., UE 104). As used herein, a transmitter may transmit a single "RF signal" or multiple "RF signals" to a receiver. However, the receiver may receive a plurality of "RF signals" corresponding to each transmitted RF signal due to the propagation characteristics of the RF signals through the multipath channel. The same transmitted RF signal on different paths between the transmitter and the receiver may be referred to as a "multipath" RF signal. The RF signal may also be referred to herein simply as a "signal".

Reference RF signals, such as Positioning Reference Signals (PRS) and Navigation Reference Signals (NRS), may be transmitted through a plurality of Resource Elements (REs) of one slot (e.g., 0.5ms) of one subframe (e.g., 1ms) of one radio frame (e.g., 10 ms). An RE is one time-frequency resource of one subcarrier (also referred to as a "tone") in the frequency domain and one Orthogonal Frequency Division Multiplexing (OFDM) symbol in the time domain. One slot may be divided into, for example, seven OFDM symbols in the time domain. One OFDM symbol/slot/subframe/frame may be divided into, for example, 12 subcarriers or tones in the frequency domain. The reference RF signal is referred to as comb 1 if it is transmitted through each tone of one OFDM symbol, and as comb 4 if it is transmitted through every fourth tone of one OFDM symbol.

In 5G, the frequency spectrum in which a wireless node (e.g., base station 102/180, UE 104/182) operates is divided into multiple frequency ranges FR1 (from 450 to 6000MHz), FR2 (from 24250 to 52600MHz), FR3 (above 52600MHz), and FR4 (between FR1 to FR 2). In a multi-carrier system (such as 5G), one of the carrier frequencies is referred to as a "primary carrier" or "anchor carrier" or "primary serving cell" or "pcell", while the remaining carrier frequencies are referred to as a "secondary carrier" or "secondary serving cell" or "scell". In carrier aggregation, an anchor carrier is a carrier operating on a primary frequency used by the UE 104/182 (e.g., FR1) and a cell in which the UE 104/182 performs an initial Radio Resource Control (RRC) connection establishment procedure or initiates an RRC connection reestablishment procedure. The primary carrier carries all common and UE-specific control channels. The secondary carrier is a carrier operating on a second frequency (e.g., FR2) that may be configured and used to provide additional radio resources once an RRC connection between the UE 104 and the anchor carrier is established. The secondary carrier may contain only necessary signaling information and signals, e.g., those that are UE-specific may not be present in the secondary carrier, as both the primary uplink and downlink carriers are typically UE-specific. This means that different UEs 104/182 in one cell may have different downlink primary carriers. The same is true for the uplink primary carrier. The network can change the primary carrier of any UE 104/182 at any time. This is done, for example, to balance the load on the different carriers. Since a "serving cell" (whether it is a P-cell or an S-cell) corresponds to one carrier frequency/component carrier with which a certain base station communicates, the terms "cell", "serving cell", "component carrier", "carrier frequency", etc. may be used interchangeably.

For example, still referring to fig. 1, one of the frequencies used by the macrocell base station 102 may be an anchor carrier (or "pcell"), while the other frequencies used by the macrocell base station 102 and/or the mmW base station 180 may be secondary carriers ("scells"). The simultaneous transmission and/or reception of multiple carriers enables the UE 104/182 to significantly increase its data transmission and/or reception rate. For example, two 20MHz aggregated carriers in a multi-carrier system would theoretically bring about a two-fold increase in data rate (i.e., 40MHz) compared to the data rate achieved by a single 20MHz carrier.

The wireless communication system 100 may further include one or more UEs (such as UE 190) indirectly connected to one or more communication networks via one or more device-to-device (D2D) end-to-end (P2P) links. In the example of fig. 1, the UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., the UE 190 may indirectly acquire a cellular connection through therebetween) and a D2D P2P link 194 with the WLAN STA 152 connected to the WLAN AP 150 (the UE 190 may indirectly acquire a WLAN-based internet connection through therebetween). In one example, any well-known D2D RAT may be utilized (such as LTE-direct (LTE-D), WiFi-direct (WiFi-D),Etc.) to support the D2D P2P links 192 and 194.

The wireless communication system 100 may further include a UE 164 that may communicate with the macrocell base station 102 via a communication link 120 and/or with the mmW base station 180 via a mmW communication link 184. For example, the macrocell base station 102 may support a P-cell and one or more S-cells for the UE 164, and the mmW base station 180 may support one or more S-cells for the UE 164.

According to various aspects, fig. 2A illustrates an example wireless network architecture 200. For example, the NGC 210 (also referred to as a "5 GC") may be functionally viewed as a control plane function 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and a user plane function 212 (e.g., UE gateway function, access to a data network, IP routing, etc.) that may operate cooperatively to form a core network. A user plane interface (NG-U)213 and a control plane interface (NG-C)215 connect the gNB 222 to the NGC 210, and in particular to the control plane functions 214 and the user plane functions 212. In an additional configuration, the eNB 224 may also be connected to the NGC 210 via NG-C215 to the control plane function 214 and NG-U213 to the user plane function 212. Further, eNB 224 may communicate directly with the gNB 222 via a backhaul connection 223. In some configurations, the new RAN 220 may have only one or more gnbs 222, while other configurations include one or more of enbs 224 and gnbs 222 in both enbs 224 and gnbs 222. The gNB 222 or the eNB 224 may communicate with a UE 204 (e.g., any of the UEs depicted in fig. 1). Another optional aspect may include a location server 230 (which may correspond to location server 172), which location server 230 may communicate with the NGC 210 to provide location assistance for the UE 204. Location server 230 may be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules distributed across multiple physical servers, etc.), or alternatively may each correspond to a single server. The location server 230 may be configured to support one or more location services for UEs 204 that may be connected to the location server 230 via the core network NGC 210 and/or via the internet (not illustrated). Further, the location server 230 may be integrated into a component of the core network or alternatively may be located external to the core network.

According to various aspects, fig. 2B illustrates another example wireless network architecture 250. For example, the NGC 260 (also referred to as a "5 GC") may be viewed functionally as a control plane function provided by an access and mobility management function (AMF)/User Plane Function (UPF)264 and a user plane function provided by a Session Management Function (SMF)262 that operate cooperatively to form a core network (i.e., the NGC 260). User plane interface 263 and control plane interface 265 connect eNB 224 to NGC 260, specifically to SMF 262 and AMF/UPF 264, respectively. In an additional configuration, the gNB 222 may also be connected to the NGC 260 via a control plane interface 265 to the AMF/UPF 264 and a user plane interface 263 to the SMF 262. Further, eNB 224 may communicate directly with gNB 222 via backhaul connection 223, with or without a direct connection to NGC 260. In some configurations, the new RAN 220 may have only one or more gnbs 222, while other configurations include one or more of enbs 224 and gnbs 222 in both enbs 224 and gnbs 222. The gNB 222 or the eNB 224 may communicate with a UE 204 (e.g., any of the UEs depicted in fig. 1). The base stations of the new RAN 220 communicate with the AMF side of the AMF/UPF 264 over an N2 interface and with the UPF side of the AMF/UPF 264 over an N3 interface.

The functions of the AMF include registration management, connection management, reachability management, mobility management, lawful interception, transmission of Session Management (SM) messages between UE 204 and SMF 266, transparent proxy service for routing SM messages, access authentication and authorization, transmission of Short Message Service (SMs) messages between UE 204 and a Short Message Service Function (SMSF) (not shown), and a security anchor function (SEAF). The AMF 264 also interacts with an authentication server function (AUSF) (not shown) and the UE 204 and receives intermediate keys established as a result of the UE 204 authentication procedure. In case of UMTS (universal mobile telecommunications system) subscriber identity module (USIM) based authentication, the AMF retrieves security material from the AUSF. The functions of the AMF also include Secure Context Management (SCM). The SCM receives its key from the SEAF for deriving the access network specific key. The functions of the AMF also include location service management for administrative services, transmission of location service messages between the UE 204 and a Location Management Function (LMF)270 (which may correspond to the location server 172) and between the new RAN 220 and the LMF 270, EPS bearer identifier allocation for interworking with an Evolved Packet System (EPS), and UE 204 mobility event notification. In addition, the AMF also supports the functionality of non-third generation partnership project (3GPP) access networks.

The functions of the UPF include acting as an anchor point for intra-RAT/inter-RAT mobility (when applicable), acting as an external Protocol Data Unit (PDU) session point for interconnection with a data network (not shown), providing packet routing and forwarding, packet detection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) handling for the user plane (e.g., UL/DL rate enforcement, reflective QoS marking in DL), UL traffic verification (service data flow (SDF) to QoS flow mapping), transport layer packet marking in UL and DL, DL packet buffering and DL data notification triggering, and sending and forwarding one or more "end marker" to the source node.

The functions of the SMF 262 include session management, UE Internet Protocol (IP) ground allocation and management, selection and control of user plane functions, configuration of traffic steering at the UPF for routing traffic to the appropriate destination, control of the policy enforcement and QoS components, and downlink data notification. The interface through which SMF 262 communicates with the AMF side of AMF/UPF 264 is referred to as the N11 interface.

Another optional aspect may include an LMF 270, and the LMF 270 may communicate with the NGC 260 to provide location assistance for the UE 204. LMFs 270 may be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules distributed across multiple physical servers, etc.), or alternatively may each correspond to a single server. The LMF 270 may be configured to support one or more location services for UEs 204 that may be connected to the LMF 270 via the core network NGC 260 and/or via the internet (not shown).

According to various aspects, fig. 3 illustrates one example base station 302 (e.g., eNB, gNB, small cell AP, WLAN AP, etc.) in a wireless network communicating with one example UE 304 in accordance with aspects of the present disclosure. Base station 302 can correspond to any of the base stations described herein. In the DL, IP packets from the core network (NGC 210/EPC 260) may be provided to the controller/processor 375. Controller/processor 375 implements the functions of a Radio Resource Control (RRC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, and a Medium Access Control (MAC) layer. Controller/processor 375 provides RRC layer functions associated with broadcast of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification) and handover support functions; RLC layer functions associated with transmission of upper layer Packet Data Units (PDUs), error correction by automatic repeat request (ARQ), concatenation, segmentation and reassembly of RLC Service Data Units (SDUs), re-segmentation of RLC data PDUs, and re-ordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel priority processing.

A Transmit (TX) processor 316 and a Receive (RX) processor 370 implement layer 1 functions associated with various signal processing functions. Layer 1, which includes the Physical (PHY) layer, may include error detection on transport channels, Forward Error Correction (FEC) encoding/decoding of transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to one OFDM subcarrier, multiplexed with a reference RF signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time-domain OFDM symbol stream. The OFDM streams are spatially precoded to produce a plurality of spatial streams. The channel estimates from channel estimator 374 may be used to determine coding and modulation schemes and for spatial processing. The channel estimate may be derived from the reference RF signal and/or the channel condition feedback sent by the UE 304. Each spatial stream may then be provided to one or more different antennas 320 via a separate transmitter 318 a. Each transmitter 318a may modulate an RF carrier with a respective spatial stream for transmission.

At the UE 304 (which may correspond to any of the UEs described herein), each receiver 354a receives a signal through its respective antenna 352. Each receiver 354a recovers information modulated onto an RF carrier and provides the information to RX processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functions associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams intended for the UE 304. If multiple spatial streams are intended for the UE 304, they may be combined into a single OFDM symbol stream by the RX processor 356. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency-domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises one separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference RF signal are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 302. These soft decisions may be based on channel estimates computed by channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by base station 302 on the physical channel. The data and control signals are then provided to a controller/processor 359 that implements layer 3 and layer 2 functionality.

The controller/processor 359 can be associated with memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression and control signal processing to recover IP packets from the core network. The controller/processor 359 is also responsible for error detection.

Similar to the functionality described in connection with the DL transmission by the base station 302, the controller/processor 359 provides RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression/decompression and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functions associated with transmission of upper layer PDUs, error correction by ARQ, concatenation, segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and re-ordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto Transport Blocks (TBs), demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction by hybrid automatic repeat request (HARQ), priority handling, and logical channel priority processing.

Channel estimates, derived by a channel estimator 358 from a reference RF signal or feedback transmitted by base station 302, may be used by TX processor 368 to select appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by TX processor 368 may be provided to different antennas 352 via separate transmitters 354 b. Each transmitter 354b may modulate an RF carrier with a respective spatial stream for transmission. In one aspect, the transmitter 354b and the receiver 354a may be one or more transceivers, one or more discrete transmitters, one or more discrete receivers, or any combination thereof.

UL transmissions are processed at the base station 302 in a manner similar to that described in connection with receiver functionality at the UE 304. Each receiver 318b receives a signal through its corresponding antenna 320. Each receiver 318b recovers information modulated onto an RF carrier and provides the information to RX processor 370. In an aspect, the transmitter 318a and receiver 318b may be one or more transceivers, one or more discrete transmitters, one or more discrete receivers, or any combination thereof.

The controller/processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 304. IP packets from controller/processor 375 may be provided to the core network. Controller/processor 375 is also responsible for error detection.

Fig. 4 illustrates an example wireless communication system 400 in accordance with various aspects of the disclosure. In the example of fig. 4, a UE 404, which may correspond to any of the UEs described herein, is attempting to compute an estimate of its location, or assisting another example (e.g., a base station or core network component, another UE, a location server, a third party application, etc.) in computing an estimate of its location. The UE 404 may wirelessly communicate with a plurality of base stations 402-1, 402-2, and 402-3 (collectively referred to as base stations 402) that may correspond to any combination of the base stations described herein, using RF signals and standardized protocols for modulation of RF signals and exchange of information packets. By extracting different types of information from the exchanged RF signals, and using the layout of the wireless communication system 400 (e.g., the location, geometry, etc. of the base stations), the UE 404 may determine its location in a predefined reference coordinate system or provide assistance in determining its location. In an aspect, the UE 404 may specify its location using a two-dimensional (2D) coordinate system; however, the aspects disclosed herein are not limited thereto, and may also be applicable to determining a position using a three-dimensional (3D) coordinate system if additional dimensions are required. Additionally, although fig. 4 shows one UE 404 and four base stations 402, it should be appreciated that there may be more UEs 404 and more or fewer base stations 402.

To support location estimation, the base station 402 may be configured to broadcast reference RF signals (e.g., PRS, NRS, Transmitter Reference Signal (TRS), cell-specific reference signal (CRS), channel state information reference signal (CSI-RS), Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), etc.) to UEs 404 in its coverage area to enable the UEs 404 to measure characteristics of such reference RF signals. For example, the observed time difference of arrival (OTDOA) positioning method defined by 3GPP (e.g., in 3GPP Technical Specification (TS) 36.355) for wireless networks providing wireless access using 5G NR) is a multipoint positioning method in which the UE 404 measures the time differences (referred to as RSTDs) between specific reference RF signals (e.g., PRS, CRS, CSI-RS, etc.) transmitted by different network nodes (e.g., base station 402, antennas of base station 402, etc.) and reports these time differences to a location server (such as location server 230 or LMF 270) or calculates a location estimate itself from these time differences.

The term "location estimate" is used herein to refer to an estimate of the location of a UE, which may be geographic (e.g., may include latitude, longitude, and possibly altitude) or municipal (e.g., may include a street address, building name, or an exact point or area within or near a building or street address (such as a particular entrance to a building, a particular room or suite in a building, or a landmark such as a town square) The specific method of taking the orientation estimation may be referred to as, for example, the "orientation method" or the "positioning method". The position estimate may include an expected error or uncertainty (e.g., by including an area or volume within which the location is expected to be included with some specified or default level of confidence).

In general, RSTD is measured between a reference network node (e.g., base station 402-1 in the example of FIG. 4) and one or more neighbor network nodes (e.g., base stations 402-2 and 402-3 in the example of FIG. 4). The reference network node remains unchanged for all RSTDs measured by the UE 404 for any single positioning purpose of OTDOA and will generally correspond to the serving cell of the UE 404 or another nearby cell with good signal strength at the UE 404. In an aspect, where the measured network node is a cell supported by a base station, the neighbor network node will typically be a cell supported by a base station different from that of the reference cell, and may have good or poor signal strength at the UE 404. The position calculation may be based on the measured time difference (e.g., RSTD) and knowledge of the position and relative transmission timing of the network nodes (e.g., related to whether the network nodes are precisely synchronized or whether each network node transmits with some known time difference relative to other network nodes).

To assist in positioning operations, a location server (e.g., location server 230, LMF 270) may provide OTDOA assistance data to a UE 404 for a reference network node (e.g., base station 402-1 in the example of fig. 4) and neighbor network nodes relative to the reference network node (e.g., base stations 402-2 and 402-3 in the example of fig. 4). For example, the assistance data may provide a center channel frequency for each network node, various reference RF signal configuration parameters (e.g., number of consecutive positioning subframes, periodicity of positioning subframes, muting sequence, frequency hopping sequence, reference RF signal Identifier (ID), reference RF signal bandwidth), network node global ID, and/or other cell-related parameters suitable for OTDOA. The OTDOA assistance data may indicate a serving cell of the UE 404 as a reference network node.

In some cases, the OTDOA assistance data may further include an "expected RSTD" parameter that provides the UE 104 with information about the RSTD values between the reference network node and each neighbor network node that the UE 404 is expected to measure at its current location, as well as the uncertainty of the expected RSTD parameter. The expected RSTD and associated uncertainty may define a search window for the UE 404 within which the UE 404 is expected to measure the RSTD value. The OTDOA assistance information may further include reference RF signal configuration information parameters that allow the UE 404 to determine when reference RF signal positioning occasions occur in signals received from various neighbor network nodes relative to reference RF signal positioning occasions of the reference network nodes, and to determine reference RF signal sequences transmitted from various network nodes to measure signal time of arrival (ToA) or RSTD.

In an aspect, although the location servers (e.g., location server 230, LMF 270) may send assistance data to the UE 404, alternatively, the assistance data may come directly from the network node (e.g., base station 402) itself (e.g., in a periodically broadcast overhead message, etc.). Alternatively, the UE 404 may detect the neighbor network node itself without using assistance data.

The UE 404 (e.g., based in part on the assistance data, if provided) may measure and (optionally) report the RSTD between pairs of received reference RF signals from the network node. Using RSTD measurements, known absolute or relative transmission timing of each network node, and known locations of the reference and neighboring network node's transmit antennas, the network (e.g., location server 230/LMF 270, base station 402) or UE 404 may estimate the location of UE 404. Specifically, the RSTD of the neighbor network node "k" relative to the reference network node "Ref" may be given as (ToA)_k–ToA_Ref) Where ToA values may be measured modulo one subframe duration (1ms) to remove the effect of measuring different subframes at different times. In thatIn the example of FIG. 4, the measured time difference between the reference cell of base station 402-1 and the cells of neighboring base stations 402-2 and 402-3 is represented as τ₂–τ₁And τ₃–τ₁Wherein, τ₁、τ₂And τ₃Representing the toas of the reference RF signals from the transmit antennas of base stations 402-1, 402-2, and 402-3, respectively. UE 440 may then convert the ToA Measurements of the different network nodes into RSTD Measurements (e.g., as defined in 3GPP TS 36.214 entitled "Physical layer; measures") and (optionally) send them to location server 230/LMF 270. The location of the UE 404 may be determined (by the UE 404 or the location server 230/LMF 270) using (i) RSTD measurements, (ii) known absolute or relative transmission timing of each network node, (iii) known locations of physical transmit antennas of reference and neighboring network nodes, and/or (iv) directional reference RF signal characteristics such as transmit direction.

Still referring to fig. 4, when UE 404 obtains a location estimate using OTDOA measurement time differences, the necessary additional data (e.g., location and relative transmission timing of network nodes) may be provided to UE 404 by a location server (e.g., location server 230, LMF 270). In some implementations, a location estimate for the UE 404 may be obtained (e.g., by the UE 404 itself or by the location server 230/LMF 270) from OTDOA measurement time differences and from other measurements made by the UE 404 (e.g., measurements of signal timing from Global Positioning System (GPS) or other Global Navigation Satellite System (GNSS) satellites). In these implementations, referred to as hybrid positioning, OTDOA measurements may help obtain a location estimate for UE 404, but may not fully determine the location estimate.

Uplink time difference of arrival (UTDOA) is a positioning method similar to OTDOA, but based on uplink reference RF signals (e.g., Sounding Reference Signals (SRS), uplink positioning reference signals (UL PRS)) transmitted by UEs (e.g., UE 304). Further, transmit and/or receive beamforming at the base station 302 and/or the UE 304 may enable broadband bandwidth at the cell edge to improve accuracy. Beam refinement may also take advantage of the channel reciprocity process in the 5G NR.

As used herein, a "network node" may be a base station (e.g., base station 302), a cell of a base station (e.g., cell of base station 302), an RRH, a DAS, an antenna of a base station (e.g., antenna of base station 302, where the position of the antenna of the base station is completely different from the position of the base station itself), an antenna array of a base station (e.g., antenna array of base station 302, where the position of the antenna array is completely different from the position of the base station itself), or any other network entity capable of transmitting a reference RF signal. Further, as used herein, a "network node" may also refer to a UE other than the UE being located.

The term "base station" may refer to a single physical transmission point or a plurality of physical transmission points, which may or may not be co-located. For example, where the term "base station" refers to a single physical transmission point, the physical transmission point may be an antenna of a base station (e.g., base station 302) corresponding to a cell of the base station. Where the term "base station" refers to multiple co-located physical transmission points, the physical transmission points may be an antenna array of the base station (e.g., as in the case of a multiple-input multiple-output (MIMO) system or where the base station uses beamforming). Where the term "base station" refers to multiple non-co-located physical transmission points, the physical transmission points may be DASs (a network of spatially separated antennas connected to a common source via a transmission medium) or RRHs (remote base stations connected to a serving base station). Alternatively, the non-collocated transmission point may be a serving base station that is receiving measurement reports from a UE (e.g., UE 304) and a neighbor base station that UE 304 is measuring its reference RF signal.

To identify the ToA of a reference RF signal transmitted by a given network node (e.g., base station 302), a UE (e.g., UE 304) first processes all resource elements jointly on the channel over which the network node is transmitting the reference RF signal and performs an inverse fourier transform to convert the received RF signal to the time domain. The conversion of the received RF signal into the time domain is referred to as an estimate of the Channel Energy Response (CER). The CER shows a peak on the channel over time, and the earliest "distinct" peak should therefore correspond to the ToA of the reference RF signal. In summary, the UE will use a noise-related quality threshold to filter out false local peaks, and therefore presumably correctly identify significant peaks on the channel. For example, the UE may choose the ToA estimate as the earliest local maximum of the CER that is at least 'X' decibel (dB) above the median of the CER and at most 'Y' dB below the primary peak on the channel. The UE determines the CER for each reference RF signal from each network node to determine the ToA for each reference RF signal from a different network node.

Fig. 5A and 5B illustrate diagrams 500A and 500B, respectively, of an exemplary CER, in accordance with aspects of the present disclosure. The y-axis of graphs 500A and 500B represents the power of the received RF signal in dB, while the x-axis represents time. In graph 500A, graph 502A shows the CER without considering SINR (defined as the power of a particular RF signal of interest divided by the sum of the interference power from all other interfering RF signals and the power of some background noise) or delay spread (the difference between the ToA of the earliest significant peak and the ToA of the latest peak) information, while graph 504A shows the CER with SINR or delay spread information considered. Likewise, in graph 500B, graph 502B shows the CER when SINR or delay spread information is not considered, and graph 504B shows the CER when it is considered.

As shown on plot 502A, the peak at 512A may be incorrectly identified as an "apparent" peak, and thus incorrectly identified as corresponding to the ToA (approximately 300 nanoseconds (ns)) of the measured reference RF signal, without consideration of SINR or delay spread information. In contrast, as shown on plot 514A, the peak at 514A is correctly identified as an "apparent" peak when the SINR or delay spread information is considered, and thus is identified as corresponding to the correct ToA (approximately 1700ns) of the measured reference RF signal. Thus, as can be seen in fig. 5A and 5B, it is much easier to identify the actual peak, as opposed to a false peak caused by background noise on the channel, when SINR and/or delay spread are considered. Thus, knowledge of the delay spread and/or SINR may provide cleaner CER and thus potentially less false detection of the first peak.

Particularly those capable of 5G NR communications, may use beamforming to transmit and receive information over a wireless channel. The transmit beams may be quasi co-located, meaning that they appear to the receiver to have the same parameters, regardless of whether the transmit antennas themselves are physically co-located. In 5G NR, there are four types of quasi-co-location (QCL) relationships. The given type of QCL relationship indicates that certain parameters for the second reference RF signal on the second transmit beam can be derived from information about the source reference RF signal on the source transmit beam. In particular, if the source reference RF signal is QCL type a, the receiver may use the source reference RF signal to estimate doppler shift, doppler spread, average delay, and delay spread of a second reference RF signal transmitted over the same channel. If the source reference RF signal is QCL type B, the receiver may use the source reference RF signal to estimate the doppler shift and doppler spread of a second reference RF signal transmitted over the same channel. If the source reference RF signal is QCL type C, the receiver may use the source reference RF signal to estimate the doppler shift and average delay of a second reference RF signal transmitted over the same channel. If the source reference RF signal is QCL type D, the receiver may estimate spatial reception parameters of a second reference RF signal transmitted through the same channel using the source reference RF signal.

Fig. 6 illustrates a graph 600 comparing a Cumulative Distribution Function (CDF) to a fully initialized distance error in meters for all UEs across a particular sampling set, in accordance with aspects of the present disclosure. Plot 602 shows the results of a comb 1PRS pattern, a transmit/receive beam pairing (i.e., both transmitter and receiver use beamforming), and a 13dB Noise Figure (NF). Plot 604 shows the results of comb 4PRS pattern, transmit/receive beam pairing, and 13dB NF. In the example of fig. 6, the comb 4 mode has an Energy Per Resource Element (EPRE) ratio of 6 dB. As can be seen in fig. 6, the performance loss occurs at the tail of the CDF, after a percentage of about 60%.

If there is a gap in the frequency domain, such as for comb 4 mode (where the reference RF signal is transmitted in the same OFDM symbol for every fourth subcarrier), it leads to aliasing that produces CER, especially in cases where the measured network nodes are far apart. Aliasing is the result of converting the frequency domain to the time domain when estimating the CER and, as shown in fig. 7, looks like a number of equally sized peaks. Fig. 7 illustrates a graph 700 of CER estimation in the case of transmitting a detected reference RF signal using comb 4 mode, in accordance with aspects of the present disclosure. As shown in fig. 7, the CER has four distinct peaks due to the fact that the reference RF signal is being transmitted through comb 4 mode and the UE (e.g., UE 304) is far away from the network node. However, the UE may not be aware of the problem, and only one of these peaks is useful. Thus, in the example of fig. 7, the UE detects the distinct peak at 702 and erroneously identifies it as the strongest detected peak. In effect, the true peak is located at 704. This is a problem with frequency domain subsampling from the use of comb 4, especially in cases where the UE is far away from the network node. For reference, the CER plots in fig. 5A and 5B show the CER for the comb 1 mode.

Therefore, it would be beneficial for a UE that has detected aliasing in the CER to be able to identify which is the true peak of the channel. Accordingly, the present disclosure proposes new QCL types that configure QCL source reference RF signals for either "average delay" (the average of the time to receive the first channel tap of a multipath RF signal and the time to receive the last channel tap of the multipath RF signal) or "delay spread" (the time from when the first channel tap of the multipath RF signal is received to when the last channel tap of the multipath RF signal is received), or both, to enable a UE (e.g., UE 304) to derive these values for subsequently transmitted reference RF signals. If another reference RF signal is received as a QCL source for "average delay" and/or "delay spread" of other reference RF signals on the channel, the UE may estimate a coarse CER from the source reference RF signal, determine a valid window in the CER at which to look for a main peak of the reference RF signal received over the channel, receive a subsequent reference RF signal, and search for ToA within the determined window. As should be appreciated, for reference RF signals that provide QCL parameters for "average delay" and/or "delay spread," the allowable actual transmission parameters may be different from those if no QCL source is provided.

Fig. 8A illustrates a graph 800A of an example CER of received reference RF signals in accordance with aspects of the present disclosure. In the example of fig. 8A, a UE (e.g., UE 304) has received a source reference RF signal (e.g., TRS) configured for only average delay. Thus, the UE will know the average delay of subsequent reference RF signals received from the network node (e.g., base station 302) over the channel. The average delay is represented as line 804. For subsequently received reference RF signals (e.g., PRSs), the UE may listen for a certain time threshold before and after the delay average to detect any significant peaks that occur within the threshold, and any detected significant peaks (here, peak 802) may be considered as true peaks of the reference RF signal.

Fig. 8B illustrates a graph 800B of an example CER of received reference RF signals in accordance with aspects of the present disclosure. In the example illustration of fig. 8B, a UE (e.g., UE 304) has received a source reference RF signal (e.g., TRS) configured for mean delay and delay spread. Thus, the UE will know the average delay and delay spread of subsequent reference RF signals received from the network node (e.g., base station 302) over the channel. The average delay and delay spread may be used to determine the window 806. The width of the window 806 is a delay spread determined from the source reference RF signal, and the center of the window 806 is set at an average delay determined from the source reference RF signal. For subsequently received reference RF signals (e.g., PRSs), the UE may search within window 806 to detect any significant peaks occurring within window 806, and any detected significant peaks (here, peak 802) may be considered as true peaks of the reference RF signal. It should be noted that multipath peaks may appear aliased to the UE. Thus, it is preferable to have both average delay and delay spread when possible.

The present disclosure proposes defining new QCL relationships and using Synchronization Signal Blocks (SSBs) as source reference RF signals for these new QCL relationships. For convenience, these new QCL types are referred to as QCL types E1, E2, and E. For QCL type E1, the UE may use a source reference RF signal (SSB) to estimate the average delay of a second reference RF signal transmitted over the same channel. For QCL type E2, the UE may use a source reference RF signal (SSB) to estimate the delay spread of a second reference RF signal transmitted on the same channel. For QCL type E, the UE may use a source reference RF signal (SSB) to estimate the average delay and delay spread of a second reference RF signal transmitted over the same channel. The QCL type (E1/E2/E) may be a field in the SSB, and based on the QCL type contained in the SSB, the UE will know which measurements (delay spread, average delay, both) it can obtain for the SSB.

Thus, a reference RF signal transmitted over a given channel may be configured with QCL type E1, type E2, or both (type E), and the configuration may be conveyed in another downlink reference RF signal, such as an SSB for a network node. Currently in 5G NR, QCL type C or type C/D is allowed when the SSB is a source reference RF signal. The present disclosure will add type E. Alternatively, statements about the following may be added to the applicable standard: when configuring the reference RF signal for QCL type D, it is implicitly assumed that either QCL type E1 or E2 or both are also true. This allows the UE to receive SSBs from a network node and, depending on the QCL type provided (E1/E2/E), make a rough estimate of the average delay and/or delay spread of the reference RF signal from the network node, and then receive subsequent reference RF signals and search for early peaks within the smaller window.

If QCL type E source reference RF signals are provided, different sets of reference RF signal transmission parameters may be used by the network node (e.g., base station 302). For example, QCL type E (either E1 or E2) would allow higher combs to be used for PRS; otherwise, a full comb PRS (e.g., comb 1) should be used. This is because aliasing is more likely to occur if a higher comb level is used. However, if the PRS is configured with a source reference RF signal (e.g., SSB) of QCL type E1/E2/E, the UE may clip out the aliased CER and look for the earliest peak within the determined window as discussed above with reference to FIGS. 8A and 8B. Further, if QCL type E source reference RF signals are provided, the comb pattern may be even higher than when only QCL type E1 source reference RF signals are provided. For example, for a QCL type E1 source, a PRS with comb type 2 may be sent, while for a QCL type E source, a PRS with comb 12 may be sent.

If a QCL type E2 (delay spread) source reference RF signal (e.g., SSB) is provided and no QCL type E1 (average delay) source is provided, the network node may use a different set of reference RF signal transmission parameters. For example, in providing QCL type E2 source reference RF signals for subsequent reference RF signals (e.g., PRSs), then orthogonal code division multiplexing of subsequent reference RF signals from different cells may be allowed with a configured cyclic shift (i.e., cyclically shifted). The cyclic shift changes the "average delay" of the channel, so in this case it can be assumed that the "average delay" of the subsequent reference RF signal is the "average delay" of the source reference RF signal plus the cyclic shift. This is illustrated in fig. 9.

In fig. 9, as shown in graph 910, the UE detects a cluster of channel taps 912 for the SSB ("SSB 1") for a first cell ("cell 1") and a cluster of channel taps 914 for the SSB ("SSB 2") for a second cell ("cell 2"). Although the UE detects SSBs 1 before SSBs 2, it knows these SSBs have been cyclically shifted and the amount of cyclic shift. Thus, the UE may add the cyclic shift to the average delay, resulting in graph 920, graph 920 accurately representing the order in which SSBs would have been received without the cyclic shift.

As another example, a UE may be configured with 'N' PRS resources from 'N' cells in the same OFDM symbol (a PRS resource is a set of resource elements used to transmit PRSs and may correspond to a beam or cell of a network node), each PRS resource having a different cyclic shift. QCL type E2 may be configured for each PRS resource by the corresponding SSB. By measuring the SSBs, the UE may determine a suitable window for each cell and may then shift the window according to the configured cyclic shift.

As yet another example, if QCL type E2 source reference RF signals (e.g., SSBs) are provided for all PRS resources transmitted over the same OFDM symbol, more cyclic shifts may be configured for the UE than if QCL type E2 were not provided.

As yet another example, if QCL type E2 source reference RF signals (e.g., SSBs) are provided and cyclic shift is used for network node (e.g., base station 302) orthogonalization, a Zadoff-Chu sequence may be used as the PRS sequence.

It should be noted that although the foregoing has been generally described in terms of a network node (such as a base station) transmitting downlink reference RF signals and QCL types to a UE, it should be appreciated that a UE may transmit uplink reference RF signals and QCL types to a network node, and different network nodes (whether base stations or UEs) may transmit reference RF signals and QCL types to each other.

Fig. 10 illustrates an example method 1000 for receiving reference RF signals for position estimation in accordance with aspects of the present disclosure. The method 1000 may be performed by a receiver (e.g., a UE 304 on the downlink or a base station 302 on the uplink).

At 1002, a receiver device (e.g., receiver 354a and/or RX processor 356 or receiver 318b and/or RX processor 370) receives a reference RF signal (e.g., SSB) from a transmission point (e.g., UE 304 on the uplink or base station 302 on the downlink, an antenna or antenna array of base station 302, RRH, DAS, etc.) over a wireless channel (e.g., communication link 120). In one aspect, the reference RF signal comprises SSBs.

At 1004, the receiver device (e.g., receiver 354a and/or RX processor 356 or receiver 318b and/or RX processor 370) receives, from a positioning entity (e.g., location server 230 or LMF 270), an indication of a source of QCL type (e.g., E1/E2/E) that the reference RF signal serves as a positioning reference RF signal received by the receiver device from a transmission point over a wireless channel.

At 1006, the receiver device (e.g., channel estimator 358 and/or RX processor 356 or channel estimator 374 and/or RX processor 370) measures an average delay, delay spread, or both the average delay and delay spread of the source reference RF signal based on the QCL type. In one aspect, the average delay comprises an average of a first time at which a first channel tap of the reference RF signal is received and a second time at which a last channel tap of the reference RF signal is received. In one aspect, the delay spread comprises an amount of time from a first time at which a first channel tap of the reference RF signal is received to a second time at which a last channel tap of the reference RF signal is received.

At 1008, a receiver device (e.g., receiver 354a and/or RX processor 356 or receiver 318b and/or RX processor 370) receives positioning reference RF signals (e.g., PRS, NRS, TRS, CRS, CSI-RS, etc.) from transmission points over a wireless channel.

At 1010, the receiver device (e.g., channel estimator 358 and/or RX processor 356 or channel estimator 374 and/or RX processor 370) identifies a ToA of the positioning reference RF signal based on the measured average delay, delay spread, or both the average delay and delay spread of the reference RF signal.

In one aspect, the method 1000 may further include (not shown) calculating a CER for the positioning reference RF signal, and identifying a ToA for the positioning reference RF signal based on peaks in the CER for the positioning reference RF signal that occur within a time period (window) defined by the average delay, the delay spread, or both the average delay and the delay spread.

In one aspect, a receiver device may be configured with multiple positioning reference RF signal resources from multiple cells, where each positioning reference RF signal resource is carried in the same OFDM symbol and has a different cyclic shift. In this case, the method 1000 further comprises (not shown): for each positioning reference RF signal resource, measuring a delay spread of a reference RF signal transmitted on the positioning reference RF signal resource; for each cell, determining a time period defined by a delay spread of a reference RF signal transmitted on a positioning reference RF signal resource of the cell; and shifting, for each cell, the time period based on the cyclic shift of the positioning reference RF signal resource of that cell. The method 1000 may further include (not shown): receiving a positioning reference RF signal from a transmission point through each of a plurality of positioning reference RF signal resources, wherein a sequence for each positioning reference RF signal is a Zadoff-Chu sequence, and wherein each cell shifts the Zadoff-Chu sequence with a respective cyclic shift.

In one aspect, the method 1000 further comprises (not shown): receiving, at the receiver device, a second reference RF signal from a second transmission point over a second wireless channel; receiving, at the receiver device from the transmission point over the second wireless channel, an indication of a second QCL type source for which the second reference RF signal serves as a positioning reference RF signal received by the receiver device from the second transmission point; measuring, by the receiver device, a second average delay, a second delay spread, or both the second average delay and the second delay spread of the second reference RF signal based on the second QCL type; receiving, at the receiver device, a second positioning reference RF signal from a second transmission point over a second wireless channel; and identifying, by the receiver device, a second ToA of the second positioning reference RF signal based on the second average delay, the second delay spread, or both the second average delay and the second delay spread of the second reference RF signal. In one aspect, the method 1000 may further include (not shown): performing a positioning operation based on the ToA of the positioning reference RF signal and a second ToA of the second positioning reference RF signal, wherein the positioning operation includes calculating an RSTD between the ToA and the second ToA. In one aspect, a receiver device reports the RSTD to a positioning entity.

In one aspect, the QCL type indicates that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread. In one aspect, based on the QCL type indicating that the reference RF signal and the positioning reference RF signal have both the same average delay and the same delay spread, the transmission point transmits the positioning reference RF signal using a higher comb pattern than if the QCL type indicating that the reference RF signal and the positioning reference RF signal have only the same average delay or only the same delay spread. In one aspect, the transmission point transmits the positioning reference RF signal using a higher comb than can be used if the QCL type does not indicate that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

Fig. 11 illustrates an example method 1100 for transmitting reference RF signals for location estimation in accordance with aspects of the present disclosure. The method 1100 may be performed by a transmission point (e.g., a UE 304 on an uplink, an antenna or antenna array of the UE 304, a base station 302 on a downlink, an antenna or antenna array of the base station 302, etc.).

At 1102, a transmission point (e.g., transmitter 318a and/or TX processor 316 or transmitter 354b and/or TX processor 368) transmits a reference RF signal over a wireless channel to a receiver device (e.g., UE 304 on the downlink or base station 302 on the uplink).

At 1104, the transmission point (e.g., transmitter 318a and/or TX processor 316 or transmitter 354b and/or TX processor 368) transmits an indication to the receiver device over the wireless channel that the reference RF signal serves as a source of QCL type for positioning reference RF signals received by the receiver device from the transmission point.

At 1106, the transmitting point (e.g., transmitter 318a and/or TX processor 316 or transmitter 354b and/or TX processor 368) transmits a positioning reference RF signal to the receiver device over the wireless channel according to a QCL type, wherein the QCL type indicates that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

In one aspect, the method 1100 further comprises (not shown): receive, from the receiver device, a ToA for a positioning reference RF signal calculated based on a measured average delay, a measured delay spread, or both a measured average delay and a measured delay spread of the reference RF signal.

In one aspect, based on the QCL type indicating that the reference RF signal and the positioning reference RF signal have both the same average delay and the same delay spread, the transmission point transmits the positioning reference RF signal using a higher comb pattern than if the QCL type indicating that the reference RF signal and the positioning reference RF signal have only the same average delay or only the same delay spread.

In one aspect, the transmission point transmits the positioning reference RF signal using a higher comb than can be used if the QCL type does not indicate that the reference RF signal and the positioning reference RF signal have only the same average delay, only the same delay spread, or both the same average delay and the same delay spread.

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Further, those of skill would appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an ASIC, a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The methods, sequences and/or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in Random Access Memory (RAM), flash memory, Read Only Memory (ROM), erasable programmable ROM (eprom), electrically erasable programmable ROM (eeprom), registers, a hard disk, a removable disk, a CD-ROM, or any other form of non-transitory computer-readable medium known in the art. An exemplary non-transitory computer readable medium can be coupled to a processor such that the processor can read information from, and write information to, the non-transitory computer readable medium. Alternatively, the non-transitory computer readable medium may be an integral part of the processor. The processor and the non-transitory computer readable medium may reside in an ASIC. The ASIC may reside in a user equipment (e.g., UE) or a base station. Alternatively, the processor and the non-transitory computer readable medium may be separate components in the user equipment or the base station.

In one or more exemplary aspects, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a non-transitory computer-readable medium. Computer-readable media may include both storage media and/or communication media including any non-transitory medium that can facilitate transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. The terms magnetic disk and optical disk, as may be used interchangeably herein, include Compact Disk (CD), laser disk, optical disk, Digital Versatile Disk (DVD), floppy disk and blu-ray disk that usually reproduce data magnetically and/or optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects, those skilled in the art will recognize that various changes and modifications can be made herein without departing from the scope of the disclosure as defined by the appended claims. Further, in light of the various illustrative aspects described herein, those of skill in the art will recognize that the functions, steps, and/or actions described above and/or recited in any method claims appended thereto need not be performed in any particular order. Still further, to the extent that any element is recited in the singular, in the above description and/or in the appended claims, those skilled in the art will recognize that the plural is contemplated unless limitation to the singular is explicitly stated.