Method for Correcting Departure Time in Observing Time Difference of Arrival Positioning

Abstract

A method, apparatus, and computer-readable storage medium for correcting the departure time of a positioning reference signal (PRR) used when estimating the position of a user equipment in a wireless network is provided. In an example implementation, the method may include: receiving, by a user equipment (UE), one or more positioning reference signals (PRS) from each of a plurality of cells. The example method may also include: determining, by the user equipment (UE), the arrival time of positioning reference signals (PRS) from different cells in the plurality of cells; and sending, by the user equipment (UE), a reference signal time difference (RSTD) value.

Description

Technical Field

[0001] The present description relates to wireless communications and, more particularly, to estimating the position of a user equipment (UE) in a wireless network. Background Art

[0002] A communication system may be a facility that enables communication between two or more nodes or devices, such as fixed or mobile communication devices. Signals may be carried on wired or wireless carriers.

[0003] An example of a cellular communication system is an architecture standardized by the Third Generation Partnership Project (3GPP). The latest development in this field is generally referred to as the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology. E-UTRA (Evolved UMTS Terrestrial Radio Access) is the air interface of the 3GPP Long Term Evolution (LTE) upgrade path for mobile networks. In LTE, a base station or access point (AP) (referred to as an enhanced node AP or evolved node B (eNB)) provides wireless access within a coverage area or cell. In LTE, a mobile device or mobile station is referred to as a user equipment (UE). LTE includes many improvements or developments.

[0004] The 5G New Radio (NR) development is part of the ongoing mobile broadband evolution process to meet the requirements of 5G, similar to the earlier evolution of 3G and 4G wireless networks. In addition, 5G targets emerging use cases beyond mobile broadband. One goal of 5G is to significantly improve wireless performance, which may include new levels of data rate, latency, reliability and security. 5G NR can also be extended to effectively connect the massive Internet of Things (IoT) and can provide new types of mission-critical services. Ultra-reliable and low-latency communication (URLLC) devices may require high reliability and extremely low latency. Summary of the invention

[0005] A method, apparatus, and computer-readable storage medium for correcting a departure time of a positioning reference signal (PRR) used when estimating a position of a user equipment in a wireless network is provided. In an example implementation, the method may include: receiving, by a user equipment (UE), one or more positioning reference signals (PRS) from each of a plurality of cells. In the example method, a second positioning reference signal (PRS) of one or more positioning reference signals (PRS) from a cell in the plurality of cells includes a second departure time of the second positioning reference signal (PRS), the second departure time being relative to a first departure time of a first reference positioning reference signal (PRS) received from the cell, the first reference positioning reference signal (PRS) being a reference positioning reference signal (PRS) first transmitted from the cell among the plurality of one or more reference positioning reference signals (PRS). The example method may also include determining, by a user equipment (UE), an arrival time of a positioning reference signal (PRS) from different cells in a plurality of cells; and sending, by the user equipment (UE), a reference signal time difference (RSTD) value, the reference signal time difference (RSTD) value of the reference signal time difference (RSTD) value being determined based on at least a first departure time and a second departure time and an arrival time of the positioning reference signal (PRS) from different cells in the plurality of cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a block diagram of a wireless network according to an example implementation.

[0007] Figure 2 is a diagram illustrating transmission of a positioning reference signal (PRS) from a cell according to additional example implementations.

[0008] Figure 3 is a diagram illustrating transmission of positioning reference signals (PRS) from multiple cells according to additional example implementations.

[0009] Figure 4 is a flow chart illustrating transmitting a reference signal time difference (RSTD) value according to an example implementation.

[0010] Figure 5 is a block diagram of a node or wireless station (eg, a base station / access point or a mobile station / user equipment / UE) according to an example implementation. DETAILED DESCRIPTION

[0011] Figure 1 is a block diagram of a wireless network 130 according to an example implementation. Figure 1In a wireless network 130, user devices (UD) 131, 132, 133, and 135, which may also be referred to as mobile stations (MS) or user equipment (UE), may be connected (and communicate) with a base station (BS) 134, which may also be referred to as an access point (AP), an enhanced Node B (eNB), or a network node. At least some of the functions of an access point (AP), a base station (BS), or an (e)Node B (eNB) may also be performed by any node, server, or host operably coupled to a transceiver (such as a remote radio head). BS (or AP) 134 provides wireless coverage within a cell 136, including to user devices 131, 132, 133, and 135. Although only four user devices are shown connected or attached to BS 134, any number of user devices may be provided. BS 134 is also connected to a core network 150 via an SI interface 151. This is just one simple example of a wireless network, and other examples may be used.

[0012] User equipment (UD) (user terminal, user equipment (UE)) may refer to a portable computing device including a wireless mobile communication device operating with or without a subscriber identity module (SIM), including but not limited to the following types of devices: a mobile station (MS), a mobile phone, a cell phone, a smart phone, a personal digital assistant (PDA), a handset, a device using a wireless modem (alarm or measurement equipment, etc.), a laptop and / or touch screen computer, a tablet, a phablet, a game console, a notebook computer and a multimedia device, for example, or any other wireless device. It should be understood that a user equipment may also be an almost exclusively uplink-only device, an example of which is a camera or camcorder that loads images or video clips to a network.

[0013] In LTE (as an example), the core network 150 may be referred to as an evolved packet core (EPC), which may include a mobility management entity (MME), one or more gateways, and other control functions or blocks, wherein the mobility management entity may handle or assist in mobility / handover of user equipment between BSs, and one or more gateways may forward data and control signals between the BS and a packet data network or the Internet.

[0014] In addition, as illustrative examples, various example implementations or techniques described herein may be applied to various types of user equipment or data service types, or may be applied to user equipment running multiple applications thereon, which may be different data service types. New radio (5G) developments may support a variety of different applications or a variety of different data service types, such as, for example: machine type communication (MTC), enhanced machine type communication (eMTC), Internet of Things (IoT) and / or narrowband IoT user equipment, enhanced mobile broadband (eMBB) and ultra-reliable low latency communication (URLLC).

[0015] IoT may refer to a growing set of objects that may have Internet or network connectivity, allowing them to send and receive information to and from other network devices. For example, many sensor-type applications or devices may monitor physical conditions or states and, for example, send reports to servers or other network devices when events occur. Machine type communications (MTC or machine-to-machine communications) may be characterized by, for example, fully automated data generation, exchange, processing, and actuation between intelligent machines with or without human intervention. Enhanced mobile broadband (eMBB) may support much higher data rates than are currently available in LTE.

[0016] Ultra-Reliable Low Latency Communication (URLLC) is a new type of data service, or new use case, that may be supported by new radio (5G) systems. This enables emerging new applications and services such as industrial automation, autonomous driving, vehicle safety, e-health services, etc. As an illustrative example, 3GPP aims to provide U-plane (user / data plane) latency connectivity of, for example, 1 millisecond with 1-1e-5 reliability. Thus, for example, a URLLC user equipment / UE may require significantly lower block error rates and low latency than other types of user equipment / UE. Thus, for example, a URLLC UE (or a URLLC application on a UE) may require shorter latency than an eMBB UE (or an eMBB application running on the UE).

[0017] Various example implementations may be applied to a variety of wireless technologies or wireless networks, such as LTE, LTE-A, 5G, IoT, MTC, eMTC, eMBB, URLLC, etc., or any other wireless network or wireless technology. These example networks, technologies, or data service types are provided as illustrative examples only.

[0018] Multiple-input multiple-output (MIMO) may refer to a technique for increasing the capacity of a radio link using multiple transmit and receive antennas to exploit multipath propagation. MIMO may include the use of multiple antennas at a transmitter and / or receiver. MIMO may include a multidimensional method for sending and receiving two or more unique data streams through one radio channel. For example, MIMO may refer to a technique for simultaneously sending and receiving more than one data signal on the same radio channel by exploiting multipath propagation. According to an illustrative example, multi-user multiple-input multiple-output (multi-user MIMO or MU-MIMO) enhances MIMO technology by allowing a base station (BS) or other wireless node to simultaneously send or receive multiple streams to user equipment or UEs of different users, which may include simultaneously sending a first stream to a first UE and a second stream to a second UE via the same (or common or shared) set of physical resource blocks (PRBs) (e.g., where each PRB may include a set of time-frequency resources).

[0019] In addition, the BS may use precoding to send data to the UE (based on a precoder matrix or precoder vector for the UE). For example, the UE may receive a reference signal or a pilot signal and may determine a quantized version of a DL channel estimate and then provide an indication of the quantized DL channel estimate to the BS. The BS may determine a precoder matrix based on the quantized channel estimate, wherein the precoder matrix may be used to focus or direct the transmitted signal energy in the direction of the best channel for the UE. In addition, each UE may use a decoder matrix to determine, for example, where the UE may receive a reference signal from the BS, determine a channel estimate for the DL channel, and then determine a decoder matrix for the DL channel based on the DL channel estimate. For example, a precoder matrix may indicate antenna weights (e.g., the amplitude / gain and phase of each weight) to be applied to an antenna array of a transmitting wireless device. Similarly, a decoder matrix may indicate antenna weights (e.g., the amplitude / gain and phase of each weight) to be applied to an antenna array of a receiving wireless device. This also applies to the UL when the UE sends data to the BS.

[0020] For example, according to an example aspect, a receiving wireless user device may determine a precoder matrix using interference suppression combining (IRC), wherein the user device may receive reference signals (or other signals) from multiple BSs (e.g., and may measure the signal strength, signal power, or other signal parameters of the signals received from each BS), and may generate a decoder matrix that may suppress or reduce signals from one or more interference sources (or interfering cells or BSs), for example, by providing a null or very low antenna gain in the direction of the interfering signal) to increase the signal to interference plus noise ratio (SINR) of the desired signal. In order to reduce the total interference from multiple different interference sources, the receiver may determine the decoding matrix using, for example, a linear minimum mean square error interference suppression combining (LMMSE-IRC) receiver. IRC receivers and LMMSE-IRC receivers are merely examples, and other types of receivers or techniques may be used to determine the decoder matrix. After determining the decoder matrix, the receiving UE / user device may apply antenna weights (e.g., each antenna weight including amplitude and phase) to multiple antennas at the receiving UE or device based on the decoder matrix. Similarly, the precoder matrix may include antenna weights that may be applied to antennas of the transmitting wireless device or node. This also applies to the receiving BS.

[0021] The present disclosure relates to Observed Time Difference of Arrival (OTDOA) and / or Downlink Time Difference of Arrival (DL-TDOA) positioning based on a specific reference signal, called Positioning Reference Signal (PRS), specifically used for positioning purposes in wireless networks.

[0022] The PRS is transmitted from a separate physical location point (e.g., cell, base station, transmission point, gNB, etc.) and is measured by the user equipment (UE) with respect to the time difference of arrival at the UE. That is, the UE measures the arrival time difference of two PRSs (e.g., PRS 1 and PRS 2) and reports to the network a corresponding reference signal time difference (RSTD) value equal to the arrival time difference corresponding to the two PRSs. Then, based on this report and other additional reports associated with other physical location points, the network may be able to estimate the location of the UE.

[0023] However, the above process of determining OTDOA and / or DL-TDOA is time-sensitive. For example, the location of the UE is estimated based on the reported arrival time, or more precisely, based on the arrival time difference of the PRS. This means that the PRS should be sent from different physical locations in a synchronized manner. However, if the PRS are not fully synchronized, the network should at least know the transmission time difference of the corresponding PRS so that the network can correct these differences when generating the reference signal time difference (RSTD) report.

[0024] In LTE, this synchronization is relatively easy because a) the location server (e.g., located in the core network) knows the potential synchronization differences of different transmission points and can therefore correct for the RSTD values; and b) each transmission point transmits a single PRS. However, in New Radio (NR) / 5G, features such as beam-specific PRS and / or dynamic PRS complicate this process.

[0025] For example, in 5G / NR, multiple PRSs may be transmitted from one transmission point, each PRS corresponding to a different beam, where these different beams are transmitted at different time instances according to a process called "beam scanning". That is, in a beamforming system, each beam transmitted at a different time instance and sequentially one after another transmits a separate PRS associated with a different PRSID. A downlink (DL) PRS resource may be defined as a set of resource elements used for NR DL PRS transmission, which may span multiple PRBs within one or more consecutive symbols within a slot. For NR DL PRS resource design, a PRS resource should have a PRS resource ID, and a PRS sequence should have a PRS sequence ID. A typical assumption is that PRS resource IDs transmitted by the same physical location are assigned the same PRS sequence ID.

[0026] The transmission of multiple PRSs per transmission point with beam-specific PRS IDs causes inefficient resource usage. In this regard, PRSs need to be configured and transmitted in a dynamic manner. This means that in scenarios where higher accuracy is required, PRSs are transmitted with increased resources (e.g., higher bandwidth and / or periodicity). More importantly, since PRSs are transmitted in a beam scanning manner in beamforming scenarios, fewer or even zero PRS resources should be allocated to beams that do not correspond to any UE requesting positioning services. In other words, this means that NR should be able to exclude certain beams from transmitting PRSs at a given time instance, resulting in an uneven overall distribution of PRSs across beams.

[0027] There are various issues associated with dynamic PRS allocation in a beamforming setting. For example, in a dynamic PRS scenario, the temporal order of PRS IDs across different beams is not static. This means that the UE does not know (and cannot directly infer) the temporal order of the PRS IDs. Therefore, the UE does not know the transmission time of the PRS IDs it receives, so that even if it forms an RSTD based on the time difference of the reception time of the PRS IDs so received, the RSTD cannot be used as such unless additional processing is applied.

[0028] It should be noted that if the dynamic PRS feature is not included but static PRS allocation is used, the problem of correcting the transmission time of PRSs transmitted from different beams still exists because the transmission time of different PRS resource IDs will still be different.

[0029] The present disclosure proposes a mechanism that assigns PRS resource IDs in a sequential manner and sends a sequence of PRS resource IDs as part of location assistance information via the LPP protocol. In one embodiment, the technical solution to the above problem may include a method that provides the UE with the necessary information for correcting the departure time difference of the PRS resource IDs received by the UE. Therefore, the steps of the present invention involve adding additional information to the PRS resource ID that reflects the departure time of a given PRS resource ID. In another example implementation, this information about the departure time of the corresponding PRS resource ID can be encoded into the PRS resource ID number itself.

[0030] Figure 2 is a block diagram illustrating the transmission of a positioning reference signal (PRS) from a cell (e.g., cell 100) according to an example implementation. In some implementations, a cell may also be referred to as a base station, a physical location point, a transmission point, a gNB (next generation NB / gNB or 5G NB), or an eNB.

[0031] like Figure 2 As shown, cell 100 may be configured to transmit one or more PRSs. In an example implementation, cell 100 may be configured to transmit PRSs 101-110. Each of PRSs 101-110 may be associated with a different PRS resource ID and may further be associated with a different beam transmitted from the cell. Figure 2 In the beamforming system shown, beams may be transmitted from a cell one after another, and each beam may transmit its own PRS and be associated with a different PRS resource ID. In some implementations, beams may be transmitted in a beam scanning order, which indicates that beams (and therefore PRSs) are transmitted in a given order. In the present disclosure, the term PRS may be used interchangeably with PRS resource ID. For example, PRS 101 may also be referred to as PRS resource ID 101, etc.

[0032] Furthermore, in some implementations, the PRS resource ID may be associated with the PRS cell ID. Figure 2As shown, PRS resource IDs 101-110 can be associated with PRS cell ID #10. That is, a set of PRS resource IDs can be grouped together as a set and associated with a PRS cell ID (e.g., a cell ID value of 10). In some implementations, this can allow the departure time (or departure time information) of the PRS resource ID from the cell to be indicated in a relative manner (rather than an absolute manner). In other words, the departure time of the PRS / PRS resource ID can be expressed as a departure time relative to the following items: the departure time of the first PRS resource ID sent from the cell, and the number of time units (e.g., milliseconds ms) between consecutive PRS resource IDs of the PRS cell ID. In some implementations, the PRS cell ID can be referred to as a PRS cell identifier, a PRS resource ID, etc. In some implementations, the association between the PRS resource ID, the PRS cell ID, and the relative time information can be forwarded to the UE via the observed time difference of arrival (OTDOA) in LTE or the downlink time difference of arrival (DL-TDOA) assistance information in 5G / LTE.

[0033] In some implementations, although the cell 100 is configured to support the transmission of PRS 101-110, the cell 100 (PRS cell ID #10) may not always transmit all PRS (PRS 101-110). In some implementations, the cell 100 may support the transmission of PRS in a dynamic manner. For example, in some implementations, the cell 100 may transmit PRS resource IDs 106, 109, and 110, such as Figure 2 In other words, in some implementations, the cell 100 may skip transmitting some beams (and thus corresponding PRSs) from the cell.

[0034] In some implementations, the PRS / PRS resource ID sent from the cell may include (or convey) the following information: i) a PRS cell ID associated with the PRS resource ID and ii) a departure time of the PRS resource ID from the cell. The departure time of the PRS resource ID may be indicated as a departure time relative to a departure time of a first PRS resource ID sent from the cell (e.g., a departure time of the PRS resource ID relative to a departure time of a PRS resource ID 106 that was first sent from the cell (e.g., before any other PRS resource IDs sent from the cell) (e.g., before any other PRS resource IDs sent from the cell) Figure 2 in the example scene)).

[0035] In some implementations, for example, Figure 2As shown, the cell 100 may transmit PRS / PRS resource IDs 106, 109, and 110 in a dynamic manner and beam scanning order. For example, the PRS resource ID 106 may include information that the PRS resource ID 106 is associated with the PRS cell ID #10 and the relative departure time of the PRS resource ID 106, which may be zero because the PRS resource ID 106 is the first PRS resource ID transmitted from the cell 100. It should be noted that although the cell 100 may be configured with ten PRSs (PRSs 101-110), only PRSs 106, 109, and 110 are transmitted from the PRS cell ID #10 in a given occasion, such as a PRS positioning occasion. In some implementations, for example, in another positioning occasion, the PRS transmitted from the PRS cell ID #10 may be changed from PRSs 106, 109, and 110 to PRSs 105 and 109, for example, depending on the number of UEs in the area requesting positioning services (e.g., less or more). In some implementations, for example, PRS resource ID 109 may include information that PRS resource ID 109 is associated with PRS cell ID #10 and a relative departure time of PRS resource ID 109, which may be 1X because PRS resource ID 109 is a second PRS resource ID transmitted from PRS cell ID 10, where X represents a time difference between consecutive PRS resource ID transmissions from PRS cell ID #10. Similarly, in some implementations, for example, PRS resource ID 110 may include information that PRS resource ID 110 is associated with PRS cell ID #10 and a relative departure time of PRS resource ID 110, which may be 2X because PRS resource ID 110 is a third PRS resource ID transmitted from PRS cell ID #10 (e.g., X represents a time difference between consecutive PRS resource ID transmissions).

[0036] In some implementations, the PRS resource ID may be modified such that the PRS resource ID includes a value of a PRS index (or a PRS index value). The PRS index may be considered a counter that is specific to each cell (e.g., specific to each PRS cell ID) and / or each PRS resource ID. For example, the PRS index may be an integer that may be incremented by a value of 1 each time a new PRS resource ID is sent from a cell. In some implementations, the PRS index may be reset to zero each time a first PRS resource ID (also referred to as a reference PRS resource ID) is sent from a cell.

[0037] In some implementations, the PRS index may convey departure time information for the PRS resource ID. The departure time information may be relative to the departure time of a reference PRS resource ID (e.g., the first PRS resource ID sent from the cell before any other PRS resource ID is sent from the cell). In other words, each PRS resource ID sent from the cell may contain information about how much time has passed after the first PRS resource ID was sent from the cell and before the current PRS resource ID is being sent (in other words, the time between). For example, if Figure 2 As shown, the PRS index value sent from PRS Cell ID #10 may be as follows:

[0038] PRS Index (10,106) = 1

[0039] PRS Index (10,109) = 2, and

[0040] PRS index (10,110) = 3

[0041] The above example indicates that PRS resource IDs 106, 109, and 110 are transmitted from PRS cell ID #10, and PRS resource ID 106 is the first PRS resource ID being transmitted from the cell. Based on the time difference X (ms) between consecutive PRS transmissions from PRS cell ID #10, PRS index values ​​1, 2, and 3 indicate time differences of 0, 1X, and 2X.

[0042] Figure 3 is a block diagram illustrating transmission of positioning reference signals (PRS) or PRS resource IDs from multiple cells (eg, cells 100, 200, and 300) according to an example implementation.

[0043] In some implementations, UE 150 (which may be associated with Figure 1The user equipment 131-135 (which is the same or similar to) may receive PRS from cells 100, 200 and / or 300. A location server (also referred to as a location management function (LMF) in 5G / NR or a gateway mobile positioning center (GMLC) in LTE) may rely on information from these cells (e.g., a serving cell and two neighboring cells) to estimate the location of the UE. In some implementations, a UE (e.g., UE 150) may determine RSTD values ​​and report them to a network entity residing in a core network (e.g., via a serving cell). For example, such a core network entity may be referred to as a location server (e.g., a gateway mobile location center (GMLC) in LTE; a location management function (LMF) in 5G / NR). In addition to the information received from the UE, the focus server may rely on information related to the physical location of the cell and calculate (e.g., determine, calculate, etc.) the estimated location of the UE. It should be noted that communication between the UE and the location server is established via the non-access stratum (NAS) of the UE's serving cell (e.g., cell 100 / PRS cell ID #10). In an example implementation, Figure 3 PRS / PRS resource IDs transmitted from three cells (cells 100, 200, and 300) having PRS cell IDs of 10, 20, and 30, respectively, are shown. In some implementations, the UE may report RSTD values ​​to a network entity residing in a radio access network (RAN), which may be configured with location management capabilities as described above (e.g., a local LMF residing in the RAN). In such an example implementation, communications between the UE and the RAN-based entity may be established, for example, via a radio resource control (RRC) protocol.

[0044] In some implementations, for example, Figure 3 As shown (and referenced above Figure 2Detailed description), PRS cell ID #10 may transmit PRS / PRS resource IDs 106, 109, and 110 in a dynamic manner and in a beam scanning order. For example, PRS resource ID 106 may include information that PRS resource ID 106 is associated with PRS cell ID #10 and a relative departure time of PRS resource ID 106, which may be zero because PRS resource ID 106 is the first PRS resource ID transmitted from PRS Cell ID #10. It should be noted that although PRS Cell ID #10 may be configured with ten PRSs (PRSs 101-110), only PRS resource IDs 106, 109, and 110 may be transmitted from PRS cell ID #10 at a given opportunity, for example, a PRS positioning opportunity. In some implementations, for example, in another positioning occasion, the PRS transmitted from PRS Cell ID #10 may be changed, for example, from PRS 106, 109, and 110 to PRS 105 and 109, depending on the number of UEs in the area requesting positioning services (e.g., fewer or more). In addition, in some implementations, for example, PRS resource ID 109 may include information that PRS resource ID 109 is associated with PRS Cell ID #10 and a relative departure time of PRS resource ID 109, which may be IX because PRS 109 is the second PRS resource ID transmitted from PRS Cell ID #10, where X represents the time difference between consecutive PRS resource ID transmissions of PRS Cell ID #10. Similarly, in some implementations, for example, PRS resource ID 110 may include information that PRS resource ID 110 is associated with PRS cell ID #10 and a relative departure time of PRS resource ID 110, which may be 2X because PRS 110 is the third PRS resource transmitted from PRS cell ID #10 (X represents the time difference between consecutive PRS resource ID transmissions of PRS cell ID #10).

[0045] Similarly, in some implementations, for example, Figure 3 As shown, PRS cell ID #20 can transmit PRS / PRS resource IDs 202, 207, 208, and 210 in a dynamic manner and beam scanning order. For example, PRS resource ID 202 can include information that PRS resource ID 202 is associated with PRS cell ID #20 and a relative departure time of PRS resource ID 202, which can be zero because PRS 202 is the first PRS resource ID transmitted from PRS cell ID #20. It should be noted that although PRS Cell ID #20 can be configured to transmit 10 PRSs (PRS 201-210), in Figure 3In the example implementation of , only PRS 202, 207, 208, and 210 are transmitted from PRS Cell ID #20. In addition, in some implementations, for example, PRS resource ID 207 may include information associated with PRS resource ID 207 and PRS cell ID #20 and a relative departure time of PRS resource ID 207, which may be 1Y, because PRS resource ID 207 is the second PRS resource ID transmitted from PRS cell ID #20, where Y represents the time difference between consecutive PRS resource ID transmissions of PRS cell ID #20. Similarly, in some implementations, for example, PRS resource ID 208 may include information associated with PRS resource ID 208 and PRS cell ID #20 and a relative departure time of PRS resource ID 208, which may be 2Y, because PRS 208 is the third PRS resource ID transmitted from PRS cell ID #20 (Y represents the time difference between consecutive PRS resource ID transmissions of PRS cell ID #20).

[0046] Similarly, in some implementations, for example, Figure 3 As shown, PRS cell ID #30 may transmit PRS / PRS resource IDs 305 and 306 in a dynamic manner and beam scanning order. For example, PRS resource ID 305 may include information that PRS resource ID 305 is associated with PRS cell ID #30 and a relative departure time of PRS resource ID 305, which may be zero because PRS resource ID 305 is the first PRS resource ID transmitted from PRS cell ID #30. It should be noted that although PRS cell ID #30 may be transmitted together with ten PRSs (PRS 301-310), only PRS resource IDs 305 and 306 may be transmitted from PRS cell ID #30. Furthermore, in some implementations, for example, PRS resource ID 306 may include information that PRS resource ID 306 is associated with PRS cell ID #30 and a relative departure time of PRS resource ID 306, which may be 1Z because PRS 306 is the second PRS resource ID transmitted from PRS cell ID #30, where Z represents the time difference between consecutive PRS resource ID transmissions of PRS cell ID #30.

[0047] For example, in some implementations, UE 150 may receive PRS resource IDs 109 and 207 from PRS cell ID #10 and PRS cell ID #20, respectively (e.g., from cells 100 and 200, respectively), as follows:

[0048] PRS index (10,109) = 2

[0049] PRS Index (20,207) = 2

[0050] Upon receiving the above-mentioned PRS resource IDs, the UE 150 may determine that the PRS resource ID 109 is transmitted second from the PRS cell ID #10 and the PRS resource ID 207 is transmitted second from the cell ID 20. The PRS resource ID may further indicate that the X and Y values ​​(e.g., via OTDOA / DL-TDOA assistance information) represent the time difference between consecutive PRS transmissions from the PRS cell ID #10 and the PRS cell ID #20, respectively. In some implementations, the UE 150 may further determine the arrival time of the PRS resource ID 109 and the PRS resource 207 as T1 and T2, respectively, and may determine the RSTD values ​​associated with these PRS resource IDs as follows, where "a" and "b" (e.g., using the formula a=PRS index (10, 109)-1; b=PRS index (20, 207)-1) represent the relative time difference from the reference PRS in the PRS cell IDs 10 and 20, respectively:

[0051] RTSD 109，207 =(T1-aX)-(T2-bY)

[0052] In a similar example, UE 150 may determine RSTD values ​​associated with PRS resource IDs 109 and 208 as follows, where T3 represents the arrival time of PRS resource ID 208 .

[0053] RTSD 109，208 =(T1-X)-(T3-2Y)

[0054] In a further similar example, UE 150 may determine the RSTD values ​​associated with PRS resource IDs 109 and 305 as follows, where T4 represents the arrival time of PRS resource ID 305. Figure 3 In the example of , since the PRS index (30,305) = 1, the time unit corrected from T4 is zero, as shown below.

[0055] RTSD 109，305 =(T1-X)-(T4-0·Z)=(T1-X)-T4

[0056] In the above examples, the RSTD values ​​(RTSD 109 , 208 and RTSD 109 , 305 ) may be sufficient to provide a two-dimensional estimate of the location of the UE receiving the corresponding PRS from the corresponding cell.

[0057] In some implementations, the UE (e.g., UE 150) may report the RSTD value determined above to the network, for example, to an entity residing in the core network. In an example implementation, such a core network entity may be a location server, which may be referred to as a gateway mobile location center (GMLC) and a location management function (LMF) in 5G / NR. In some implementations, the UE may report the RSTD value to a network entity residing in a radio access network (RAN), which may be configured with a location management capability as described above (e.g., a local LMF residing in the RAN). In such an example implementation, communication between the UE and a RAN-based entity may be established, for example, via a radio resource control (RRC) protocol. Because the location server knows the physical location of the cell, the location server estimates the location of the UE 150 based on the RSTD report it receives from the UE 150.

[0058] Therefore, the above mechanism provides the ability to estimate the location of the UE to provide better service.

[0059] Figure 4 4 is a flow chart illustrating transmission of a reference signal time difference (RSTD) value from a user equipment (UE), such as UE 150, according to an example implementation.

[0060] At block 410, the UE may receive one or more PRSs from each of the plurality of cells. For example, in some implementations, the UE 150 may receive one or more PRSs from each of the plurality of cells (e.g., cells 100, 200, and 300), such as Figure 3 In some implementations, as described above, UE 150 may receive at least one PRS from three different cells, including a serving cell (eg, cell 100) and two neighboring cells (eg, cells 200 and 300).

[0061] In the example implementation, Figure 3 As shown, UE 150 may receive the following PRS resource IDs from PRS cell ID #10: 106, 109, and 110 from PRS cell ID #10; 202, 207, 208, and 210 from PRS cell ID #20; and 305 and 306 from PRS cell ID #30. Figure 2 and 3 As described, each PRS resource ID may convey a PRS cell ID indicating the cell from which the PRS resource ID was sent and the relative departure time of the PRS resource ID from the cell.

[0062] For example, in one implementation, PRS resource ID 109 may relay PRS resource ID 109 from PRS cell ID #10 and a relative departure time of 1X μs; PRS resource ID 207 may relay PRS resource ID 207 from PRS cell ID #20 and a relative departure time of 1Y μs; and PRS resource ID 305 may relay PRS resource ID 109 from PRS cell ID #30 and a relative departure time of 0 μs.

[0063] The UE 150 may receive this information via the PRS resource ID based on the index value. For example, in some implementations, the PRS resource IDs may be configured in such a way that they convey an index value for each PRS resource ID from a cell.

[0064] At block 420, the UE may determine the arrival times of the PRSs from different cells of the plurality of cells. For example, in some implementations, as described above, the UE 150 may determine the arrival times (e.g., T1, T2, T3, T4, etc.), as described above. The arrival time is a "time stamp" that the UE assigns to the event of receiving the PRS. That is, the UE may use its own clock to mark the time instances when the PRSs are received from different cells. The UE then compares these time stamps to form the RSTD.

[0065] At block 430, the UE may send the RSTD value. The RTSD value may be as described above with reference to Figure 2 and 3 Definitely as described.

[0066] Additional example implementations are described herein.

[0067] Example 1. A method of communication, comprising: receiving, by a user equipment (UE), one or more positioning reference signals (PRS) from each of a plurality of cells, a second positioning reference signal (PRS) from the one or more positioning reference signals (PRS) of a cell in the plurality of cells comprising a second departure time of the second positioning reference signal (PRS), the second departure time being relative to a first departure time of a first reference positioning reference signal (PRS) received from the cell, the first reference positioning reference signal (PRS) being a reference positioning reference signal (PRS) first transmitted from the cell in the plurality of one or more positioning reference signals (PRS); determining, by the user equipment (UE), arrival times of positioning reference signals (PRS) from different cells in the plurality of cells; and transmitting, by the user equipment (UE), a reference signal time difference (RSTD) value, the reference signal time difference (RSTD) value in the reference signal time difference (RSTD) value being determined based at least on the first departure time and the second departure time and arrival times of positioning reference signals (PRS) from different cells in the plurality of cells

[0068] Example 2. An example aspect of the method of Example 1, wherein each cell of the plurality of cells has a different positioning reference signal (PRS) cell identifier.

[0069] Example 3. An example aspect of the method according to Example 1 or 2, wherein each beam transmitted from a cell in the plurality of cells has a different positioning reference signal (PRS) index value based on a positioning reference signal (PRS) resource identifier of the corresponding beam.

[0070] Example 4. An example aspect of the method of Example 1 or 3, wherein a second departure time relative to the first departure time is indicated to a user equipment (UE) via an index value, wherein the index value is a positioning reference signal (PRS) index value.

[0071] Example 5. An example aspect of the method of Example 1, wherein the plurality of cells comprises at least one serving cell of a user equipment (UE) and at least two neighboring cells.

[0072] Example 6. An example aspect of the method of Example 1, wherein the reference signal time difference (RSTD) value is sent via a Long Term Evolution (LTE) Positioning Protocol (LPP).

[0073] Example 7. An example aspect of the method of Example 1, wherein a reference signal time difference (RSTD) value is sent to a network entity.

[0074] Example 8. An example aspect of the method according to Example 7, wherein the network entity is a location management function (LMF) or a gateway mobile location center (GMLC), and wherein a reference signal time difference (RSTD) value is sent to the network entity via a serving cell of the user equipment, the serving cell being a cell among the multiple cells.

[0075] Example 9. An example aspect of the method according to Example 1, wherein a second departure time of a second positioning reference signal (PRS) relative to a first departure time is indicated via a positioning reference signal (PRS) resource identifier (PRS resource ID) of the second positioning reference signal (PRS) and a value of a positioning reference signal resource identifier (PRS resource ID) relative to the first positioning reference signal (PRS).

[0076] Example 10. An apparatus comprising: at least one processor and at least one memory, the at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to perform operations, the operations comprising: receiving one or more positioning reference signals (PRS) from each of a plurality of cells, a second positioning reference signal (PRS) from the one or more positioning reference signals (PRS) of a cell in the plurality of cells comprising a second departure time of the second positioning reference signal (PRS), the second departure time being relative to a first departure time of a first reference positioning reference signal (PRS) received from the cell, the first reference positioning reference signal (PRS) being a reference positioning reference signal (PRS) first transmitted from the cell in the plurality of one or more positioning reference signals (PRS); determining arrival times of positioning reference signals (PRS) from different cells in the plurality of cells; and transmitting reference signal time difference (RSTD) values, the reference signal time difference (RSTD) values ​​in the reference signal time difference (RSTD) values ​​being determined based at least on the first departure time and the second departure time and arrival times of positioning reference signals (PRS) from different cells in the plurality of cells.

[0077] Example 11. An example aspect of the apparatus of Example 10, wherein each cell of the plurality of cells has a different positioning reference signal (PRS) cell identifier.

[0078] Example 12. An example aspect of an apparatus according to Example 10 or 11, wherein each beam transmitted from a cell in a plurality of cells has a different positioning reference signal (PRS) index value based on a positioning reference signal (PRS) resource identifier of the corresponding beam.

[0079] Example 13. An example aspect of the apparatus of Example 10 or 12, wherein a second departure time relative to the first departure time is indicated to a user equipment (UE) via an index value, wherein the index value is a positioning reference signal (PRS) index value.

[0080] Example 14. An example aspect of the apparatus of Example 10, wherein the plurality of cells comprises at least one serving cell of a user equipment (UE) and at least two neighboring cells.

[0081] Example 15. An example aspect of the apparatus of Example 10, wherein the reference signal time difference (RSTD) value is sent via a Long Term Evolution (LTE) Positioning Protocol (LPP).

[0082] Example 16. The example aspect of boxing according to Example 10, wherein a reference signal time difference (RSTD) value is sent to the network entity.

[0083] Example 17. An example aspect of an apparatus according to Example 16, wherein the network entity is a location management function (LMF) or a gateway mobile location center (GMLC), and wherein a reference signal time difference (RSTD) value is sent to the network entity via a serving cell of a user equipment, the serving cell being a cell among a plurality of cells.

[0084] Example 18. An example aspect of an apparatus according to Example 10, wherein a second departure time of a second positioning reference signal (PRS) relative to the first departure time is indicated via a positioning reference signal (PRS) resource identifier (PRS resource ID) of the second positioning reference signal (PRS) and a value of a positioning reference signal resource identifier (PRS resource ID) relative to the first positioning reference signal (PRS).

[0085] Example 19. A computer program product, comprising program instructions, which when loaded into an apparatus, execute a method, the method comprising: receiving, by a user equipment (UE), one or more positioning reference signals (PRS) from each of a plurality of cells, a second positioning reference signal (PRS) from the one or more positioning reference signals (PRS) of a cell in the plurality of cells comprising a second departure time of the second positioning reference signal (PRS), the second departure time being relative to a first departure time of a first reference positioning reference signal (PRS) received from the cell, the first reference positioning reference signal (PRS) being a reference positioning reference signal (PRS) first transmitted from the cell in the plurality of one or more positioning reference signals (PRS); determining, by the user equipment (UE), arrival times of positioning reference signals (PRS) from different cells in the plurality of cells; and sending, by the user equipment (UE), reference signal time difference (RSTD) values, the reference signal time difference (RSTD) values ​​in the reference signal time difference (RSTD) values ​​being determined based at least on the first departure time and the second departure time and arrival times of positioning reference signals (PRS) from different cells in the plurality of cells.

[0086] Example 20. An example aspect of the computer program product of Example 19, wherein each cell of the plurality of cells has a different positioning reference signal (PRS) cell identifier.

[0087] Example 21. An example aspect of a computer program product according to Example 19 or 20, wherein each beam transmitted from a cell in the plurality of cells has a different positioning reference signal (PRS) index value based on a positioning reference signal (PRS) resource identifier of the corresponding beam.

[0088] Example 22. An example aspect of a computer program product according to Example 19 or 21, wherein a second departure time relative to the first departure time is indicated to a user equipment (UE) via an index value, wherein the index value is a positioning reference signal (PRS) index value.

[0089] Example 23. An example aspect of the computer program product according to Example 19, wherein the plurality of cells comprises at least one serving cell of a user equipment (UE) and at least two neighboring cells.

[0090] Example 24. An example aspect of the computer program product of Example 19, wherein the reference signal time difference (RSTD) value is sent via a Long Term Evolution (LTE) Positioning Protocol (LPP).

[0091] Example 25. An example aspect of the computer program product of Example 19, wherein a reference signal time difference (RSTD) value is sent to a network entity.

[0092] Example 26. An example aspect of a computer program product according to Example 25, wherein the network entity is a location management function (LMF) or a gateway mobile positioning center (GMLC), and wherein a reference signal time difference (RSTD) value is sent to the network entity via a serving cell of the user equipment, the serving cell being a cell among a plurality of cells.

[0093] 27. An example aspect of a computer program product according to Example 19, wherein a second departure time of a second positioning reference signal (PRS) relative to a first departure time is indicated via a value of a positioning reference signal (PRS) resource identifier (PRS resource ID) of the second positioning reference signal (PRS) relative to a positioning reference signal resource identifier (PRS resource ID) of the first positioning reference signal (PRS).

[0094] Figure 5 is a block diagram of a wireless station (e.g., user equipment (UE) / user device or AP / gNB / MgNB / SgNB) 500 according to an example implementation. The wireless station 500 may include, for example, one or more RF (radio frequency) or wireless transceivers 502A, 502B, each of which includes a transmitter for sending signals and a receiver for receiving signals. The wireless station also includes a processor or control unit / entity (controller) 504 / 508 to execute instructions or software and control the sending and receiving of signals, and a memory 506 to store data and / or instructions.

[0095] The processor 504 may also make decisions or determinations, generate frames, packets, or messages for transmission, decode received frames or messages for further processing, and other tasks or functions described herein. For example, the processor 504, which may be a baseband processor, may generate messages, packets, frames, or other signals for transmission via the wireless transceiver 502 (502A or 502B). The processor 504 may control the transmission of signals or messages through a wireless network, and may control the reception of signals or messages via a wireless network, etc. (e.g., after being down-converted by the wireless transceiver 502). The processor 504 may be programmable and capable of executing software or other instructions stored on a memory or other computer medium to perform the various tasks and functions described above, such as one or more of the tasks or methods described above. The processor 504 may be (or may include) for example, hardware, programmable logic, a programmable processor that executes software or firmware, and / or any combination of these. For example, using other terms, the processor 504 and the transceiver 502 may be considered together as a wireless transmitter / receiver system.

[0096] In addition, refer to Figure 5, the controller (or processor) 508 can execute software and instructions and can provide overall control for the station 500 and can Figure 5 Other systems not shown in the figure provide control, such as controlling input / output devices (e.g., display, keyboard), and / or may execute software for one or more applications that may be provided on the wireless station 500, such as, for example, an email program, an audio / video application, a word processor, an IP voice application, or other applications or software. In addition, a storage medium may be provided that includes stored instructions that, when executed by a controller or processor, may cause the processor 504 or other controller or processor to perform one or more of the functions or tasks described above.

[0097] According to another example embodiment, the RF or wireless transceiver 502A / 502B may receive signals or data and / or transmit or send signals or data. The processor 504 (and possibly the transceiver 502A / 502B) may control the RF or wireless transceiver 502A or 502B to receive, transmit, broadcast or transmit signals or data.

[0098] However, these aspects are not limited to the systems given as examples, but those skilled in the art may apply the scheme to other communication systems. Another suitable communication system example is the 5G concept. It is assumed that the network architecture in 5G will be very similar to that of advanced LTE. 5G is likely to use multiple-input multiple-output (MIMO) antennas, many more base stations or nodes than LTE (the so-called small cell concept), including macro sites that operate in cooperation with smaller stations, and may also adopt various radio technologies to obtain better coverage and higher data rates.

[0099] It should be understood that future networks will most likely utilize network function virtualization (NFV), which is a network architecture concept that proposes to virtualize network node functions into "building blocks" or entities that can be operationally connected or linked together to provide services. A virtualized network function (VNF) may include one or more virtual machines that run computer program code using standard or general-purpose servers rather than custom hardware. Cloud computing or data storage may also be utilized. In radio communications, this may mean that node operations may be performed at least in part in a server, host, or node that is operably coupled to a remote radio head. Node operations may also be distributed among multiple servers, nodes, or hosts. It should also be understood that the distribution of labor between core network operations and base station operations may be different from LTE or even non-existent.

[0100] The implementation of the various techniques described herein may be implemented in a digital electronic circuit system, or in computer hardware, firmware, software, or a combination thereof. The implementation may be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, for example, in a machine-readable storage device or a propagated signal, for execution or control of its operation by a data processing device (e.g., a programmable processor, a computer, or multiple computers). The implementation may also be provided on a computer-readable medium or a computer-readable storage medium, which may be a non-transient medium. The implementation of various techniques may also include an implementation provided via a transient signal or medium, and / or a program and / or software implementation, which may be downloaded via the Internet or (multiple) other networks (wired networks and / or wireless networks). In addition, the implementation may be provided via machine type communication (MTC) and via the Internet of Things (IOT).

[0101] A computer program may be in source code form, object code form or some intermediate form, and it may be stored on some carrier, distribution medium or computer readable medium, which may be any entity or device capable of carrying the program. For example, such carriers include recording media, computer memories, read-only memories, optical and / or electrical carrier signals, telecommunication signals and software distribution packages. Depending on the required processing power, the computer program may be executed in a single electronic digital computer or distributed among multiple computers.

[0102] Furthermore, implementations of the various techniques described herein may use cyber-physical systems (CPS) (systems where collaborative computing elements control physical entities). CPS can implement and utilize a large number of interconnected ICT devices (sensors, actuators, processors microcontrollers, ...) embedded in physical objects at different locations. Mobile cyber-physical systems, where the physical system in question has inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals. The popularity of smartphones has increased interest in the field of mobile cyber-physical systems. Therefore, various implementations of the techniques described herein may be provided via one or more of these technologies.

[0103] Computer programs, such as the above-mentioned (multiple) computer programs, can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, including as a stand-alone program or as a module, component, subroutine or other unit or part thereof suitable for use in a computing environment. The computer program can be deployed to be executed on one computer or on multiple computers at one site, or distributed across multiple sites and interconnected by a communication network.

[0104] The method steps may be performed by one or more programmable processors executing a computer program or portion of a computer program to perform functions by operating on input data and generating output. The method steps may also be performed by, and the apparatus may be implemented as, special purpose logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0105] Processors suitable for executing computer programs include, for example, general and special purpose microprocessors, and any one or more processors of any type of digital computer, chip or chipset. Typically, the processor will receive instructions and data from a read-only memory or a random access memory or both. Elements of a computer may include at least one processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer may also include, or be operatively coupled to receive data from or send data to one or more mass storage devices (e.g., magneto-optical disks, magneto-optical disks, or optical disks) for storing data or to both. Information carriers suitable for containing computer program instructions and data include all forms of non-volatile memory, including, for example, semiconductor memory devices (e.g., EPROM, EEPROM) and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD ROM and DVD-ROM disks. The processor and memory may be supplemented by or incorporated into a dedicated logic circuit system.

Claims

1. A method of communication, comprising: receiving, by a user equipment (UE), one or more positioning reference signals (PRS) from each of a plurality of cells, a second positioning reference signal (PRS) from the one or more positioning reference signals (PRS) from a cell of the plurality of cells comprising a second departure time of the second positioning reference signal (PRS), the second departure time being relative to a first departure time of a first reference positioning reference signal (PRS) received from the cell, the first reference positioning reference signal (PRS) being a first positioning reference signal (PRS) transmitted from the cell; determining, by the user equipment (UE), arrival times of positioning reference signals (PRS) from different cells among the plurality of cells; as well as A reference signal time difference (RSTD) value is sent by the user equipment (UE), wherein a reference signal time difference (RSTD) value in the reference signal time difference (RSTD) value is determined by subtracting the second departure time from the arrival time of a positioning reference signal (PRS) from a different cell in the plurality of cells, wherein the reference signal time difference (RSTD) value is calculated by: RSTD=(T1-aX)–(T2-bY), where T1 is the arrival time of a positioning reference signal from a first cell among the plurality of cells, aX is the second departure time of the positioning reference signal from the first cell, T2 is the arrival time of a positioning reference signal from a second cell of the plurality of cells, and bY is the second departure time of the positioning reference signal from the second cell.

2. The method of claim 1, wherein each of the plurality of cells has a different positioning reference signal (PRS) cell identifier.

3. The method of claim 1, wherein each beam transmitted from a cell among the plurality of cells has a different positioning reference signal (PRS) index value based on a positioning reference signal (PRS) resource identifier of the corresponding beam.

4. The method of claim 1 , wherein the second departure time relative to the first departure time is indicated to the user equipment (UE) via an index value, wherein the index value is a positioning reference signal (PRS) index value. 5 . The method of claim 1 , wherein the plurality of cells include at least one serving cell of the user equipment (UE) and at least two neighboring cells.

6. The method of claim 1, wherein the reference signal time difference (RSTD) value is sent via a Long Term Evolution (LTE) Positioning Protocol (LPP).

7. The method of claim 1, wherein the reference signal time difference (RSTD) value is sent to a network entity.

8. The method of claim 7, wherein the network entity is a location management function (LMF) or a gateway mobile location center (GMLC), and wherein the reference signal time difference (RSTD) value is sent to the network entity via a serving cell of the user equipment, the serving cell being a cell among the plurality of cells.

9. The method of claim 1 , wherein the second departure time of the second positioning reference signal (PRS) relative to the first departure time is indicated via a positioning reference signal (PRS) resource identifier (PRS resource ID) of the second positioning reference signal (PRS) relative to the value of the positioning reference signal resource identifier (PRS resource ID) of the first positioning reference signal (PRS).

10. An apparatus for communication, comprising: at least one processor and at least one memory, the at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to perform operations comprising: receiving one or more positioning reference signals (PRS) from each of a plurality of cells, a second positioning reference signal (PRS) from the one or more positioning reference signals (PRS) from a cell of the plurality of cells comprising a second departure time of the second positioning reference signal (PRS), the second departure time being relative to a first departure time of a first reference positioning reference signal (PRS) received from the cell, the first reference positioning reference signal (PRS) being a first positioning reference signal (PRS) transmitted from the cell; determining a time of arrival of a positioning reference signal (PRS) from different cells of the plurality of cells; and and transmitting a reference signal time difference (RSTD) value, wherein a reference signal time difference (RSTD) value in the reference signal time difference (RSTD) value is determined by subtracting the second departure time from the arrival time of a positioning reference signal (PRS) from a different cell among the plurality of cells, wherein the reference signal time difference (RSTD) value is calculated by: RSTD=(T1-aX)–(T2-bY), where T1 is the arrival time of a positioning reference signal from a first cell among the plurality of cells, aX is the second departure time of the positioning reference signal from the first cell, T2 is the arrival time of a positioning reference signal from a second cell of the plurality of cells, and bY is the second departure time of the positioning reference signal from the second cell.

11. The apparatus of claim 10, wherein each cell of the plurality of cells has a different positioning reference signal (PRS) cell identifier.

12. The apparatus of claim 10, wherein each beam transmitted from a cell among the plurality of cells has a different positioning reference signal (PRS) index value based on a positioning reference signal (PRS) resource identifier of the corresponding beam.

13. The apparatus according to one of claims 10 or 12, wherein the second departure time relative to the first departure time is indicated to the apparatus via an index value, wherein the index value is a Positioning Reference Signal (PRS) index value.

14. The apparatus of claim 10, wherein the plurality of cells comprises at least one serving cell and at least two neighboring cells of the apparatus.

15. The apparatus of claim 10, wherein the reference signal time difference (RSTD) value is sent via a Long Term Evolution (LTE) Positioning Protocol (LPP).

16. The apparatus of claim 10, wherein the reference signal time difference (RSTD) value is sent to a network entity.

17. The apparatus of claim 16, wherein the network entity is a location management function (LMF) or a gateway mobile location center (GMLC), and wherein the reference signal time difference (RSTD) value is sent to the network entity via a serving cell of the apparatus, the serving cell being a cell among the plurality of cells.

18. The apparatus of claim 10, wherein the second departure time of the second positioning reference signal (PRS) relative to the first departure time is indicated via a positioning reference signal (PRS) resource identifier (PRS resource ID) of the second positioning reference signal (PRS), relative to the value of the positioning reference signal resource identifier (PRS resource ID) of the first positioning reference signal (PRS).

19. A computer program product comprising program instructions which, when loaded into a device, perform a method comprising: receiving, by a user equipment (UE), one or more positioning reference signals (PRS) from each of a plurality of cells, a second positioning reference signal (PRS) from the one or more positioning reference signals (PRS) from a cell of the plurality of cells comprising a second departure time of the second positioning reference signal (PRS), the second departure time being relative to a first departure time of a first reference positioning reference signal (PRS) received from the cell, the first reference positioning reference signal (PRS) being a first positioning reference signal (PRS) transmitted from the cell; determining, by the user equipment (UE), arrival times of positioning reference signals (PRS) from different cells among the plurality of cells; as well as A reference signal time difference (RSTD) value is sent by the user equipment (UE), wherein a reference signal time difference (RSTD) value in the reference signal time difference (RSTD) value is determined by subtracting the second departure time from the arrival time of a positioning reference signal (PRS) from a different cell in the plurality of cells, wherein the reference signal time difference (RSTD) value is calculated by: RSTD=(T1-aX)–(T2-bY), where T1 is the arrival time of a positioning reference signal from a first cell among the plurality of cells, aX is the second departure time of the positioning reference signal from the first cell, T2 is the arrival time of a positioning reference signal from a second cell of the plurality of cells, and bY is the second departure time of the positioning reference signal from the second cell.

20. The computer program product of claim 19, wherein each cell of the plurality of cells has a different positioning reference signal (PRS) cell identifier.

21. The computer program product of claim 19, wherein each beam transmitted from a cell of the plurality of cells has a different positioning reference signal (PRS) index value based on a positioning reference signal (PRS) resource identifier of the corresponding beam.

22. The computer program product of one of claims 19 or 21, wherein the second departure time relative to the first departure time is indicated to the user equipment (UE) via an index value, wherein the index value is a positioning reference signal (PRS) index value.

23. The computer program product of claim 19, wherein the plurality of cells comprises at least one serving cell and at least two neighboring cells of the user equipment (UE).

24. The computer program product of claim 19, wherein the reference signal time difference (RSTD) value is sent via a Long Term Evolution (LTE) Positioning Protocol (LPP).

25. The computer program product of claim 19, wherein the reference signal time difference (RSTD) value is sent to a network entity.

26. The computer program product of claim 25, wherein the network entity is a location management function (LMF) or a gateway mobile positioning center (GMLC), and wherein the reference signal time difference (RSTD) value is sent to the network entity via a serving cell of the user equipment, the serving cell being a cell among the plurality of cells.

27. The computer program product of claim 19, wherein the second departure time of the second positioning reference signal (PRS) relative to the first departure time is indicated via a value of a positioning reference signal (PRS) resource identifier (PRS resource ID) of the second positioning reference signal (PRS) relative to the first positioning reference signal (PRS).

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