The present application concerns the field of wireless communication systems and networks, more specifically to a transceiver for receiving a receive signal (plurality of RSs) to be used for position determination and to a corresponding method. Embodiments refer to LOS/NLOS identification with phase measurements.
For data transmission a physical resource grid may be used. The physical resource grid may comprise a set of resource elements to which various physical channels and physical signals are mapped. For example, the physical channels may include the physical downlink, uplink and sidelink shared channels (PDSCH, PUSCH, PSSCH) carrying user specific data, also referred to as downlink, uplink and sidelink payload data, the physical broadcast channel (PBCH) carrying for example a master information block (MIB), the physical downlink shared channel (PDSCH) carrying for example a system information block (SIB), the physical downlink, uplink and sidelink control channels (PDCCH, PUCCH, PSSCH) carrying for example the downlink control information (DCI), the uplink control information (UCI) and the sidelink control information (SCI). For the uplink, the physical channels, or more precisely the transport channels according to 3GPP, may further include the physical random access channel (PRACH or RACH) used by UEs for accessing the network once a UE is synchronized and has obtained the MIB and SIB. The physical signals may comprise reference signals or symbols (RS), synchronization signals and the like. The resource grid may comprise a frame or radio frame having a certain duration in the time domain and having a given bandwidth in the frequency domain. The frame may have a certain number of subframes of a predefined length, e.g. 1 ms. Each subframe may include one or more slots of 12 or 14 OFDM symbols depending on the cyclic prefix (CP) length. All OFDM symbols may be used for DL or UL or only a subset, e.g. when utilizing shortened transmission time intervals (sTTI) or a mini-slot/non-slot-based frame structure comprising just a few OFDM symbols.
The wireless communication system may be any single-tone or multicarrier system using frequency-division multiplexing, like the orthogonal frequency-division multiplexing (OFDM) system, the orthogonal frequency-division multiple access (OFDMA) system, or any other IFFT-based signal with or without CP, e.g. DFT-s-OFDM. Other waveforms, like non-orthogonal waveforms for multiple access, e.g. filter-bank multicarrier (FBMC), generalized frequency division multiplexing (GFDM) or universal filtered multi carrier (UFMC), may be used. The wireless communication system may operate, e.g., in accordance with the LTE-Advanced pro standard or the NR (5G), New Radio, standard.
The wireless network or communication system depicted in
In addition to the above described terrestrial wireless network also non-terrestrial wireless communication networks exist including spaceborne transceivers, like satellites, and/or airborne transceivers, like unmanned aircraft systems. The non-terrestrial wireless communication network or system may operate in a similar way as the terrestrial system described above with reference to
In mobile communication networks, for example in a network like that described above with reference to
When considering two UEs directly communicating with each other over the sidelink, both UEs may be served by the same base station so that the base station may provide sidelink resource allocation configuration or assistance for the UEs. For example, both UEs may be within the coverage area of a base station, like one of the base stations depicted in
When considering two UEs directly communicating with each other over the sidelink, e.g. using the PC5 interface, one of the UEs may also be connected with a BS, and may relay information from the BS to the other UE via the sidelink interface. The relaying may be performed in the same frequency band (in-band-relay) or another frequency band (out-of-band relay) may be used. In the first case, communication on the Uu and on the sidelink may be decoupled using different time slots as in time division duplex, TDD, systems.
Naturally, it is also possible that the first vehicle 202 is covered by the gNB, i.e. connected with Uu to the gNB, wherein the second vehicle 204 is not covered by the gNB and only connected via the PC5 interface to the first vehicle 202, or that the second vehicle is connected via the PC5 interface to the first vehicle 202 but via Uu to another gNB, as will become clear from the discussion of
The autonomous resource selection method of NR V2X sidelink transmission mode 2 consists of a sensing and a resource selection phase delimited by corresponding time windows. The resource selection is further split into two steps:
Compared to LTE V2X mode 4 the sensing is shorter but still in the order of 100 ms and essentially continuous, i.e., the sensing window is moving. The long sensing duration may cause high power consumption which is a problem for battery-powered UEs. Partial sensing is proposed to address this problem, however, this essentially reduces RSSI and RSRP measurements while in NR the SCI reception and decoding is to be ongoing to cope with aperiodic traffic. In other words, this issue already persisting in LTE V2X mode 4 has not yet been solved in NR V2X mode 2.
Resource selection involves not only the physical but also higher layers. This process could be implemented, for example, as follows:
Especially, the involvement of higher layers and signaling between the layers cause longer latency that not only delays the delivery of packets but also increases the risk of collisions since the sensing information becomes more outdated the longer the gap between sensing and transmission is. For example in [2] minimum desired values are stated for the processing times Tproc,0 (time between the end of sensing window and resource selection trigger) and Tproc,1 (maximum time between (re)selection trigger and start of selection window) with 0.5 ms and 1 ms, respectively. Depending on the numerology, 15, 30, 60 or 120 KHz the sum of these values of 1.5 ms together with additional time needed for slots alignment causes a latency between the last sensing slot and transmission of at least 3, 4, 7 or 13 slots, respectively. Since any transmission of a reservation of another UE during that time cannot be recognized in time, even if sensing is continued in the gap, a collision cannot be avoided if these reservations are overlapping, unless it is sufficiently far in the future that a pre-emption is possible.
Due to non-periodic traffic in NR V2X, the prediction of the behavior of other UEs is not possible. Though the resource reservation agreed for NR V2X mode 2 can indeed reduce the collision probability, however, the latency between sensing and resource selection yields more sensing results that are outdated which in turn increases the collision probability again, as explained above.
A known solution is specified on 3GPP RAN1. The corresponding options are described in the first proposal in section 7.2.4.2.2 of [1]. The final stage of 5G V2X in release 16, as specified in [3] chapter 16 and [4] chapter 8, is denoted as known in the following.
A correlation receiver normally identifies the first arriving path (FAP) and derives based on the FAP the measurements needed for determining a UE position (example Time of Arrival ToA measurements derived on the time the FAP is detected).
For 5G positioning several positioning methods are supported:
The accuracy of all these methods rely on LOS or NLOS condition. If the measurement device does not provides additional information beyond the timing, power or direction measurement the position calculation unit will not be able to identify the potential error and extract faulty measurement or determine the measurement quality. Therefore, there is the need for an improved approach.
According to an embodiment, a transceiver for receiving a receive signal or a plurality of receive signals to be used for position determination over multiple points of time may have: a measurement unit configured to perform a measurements to detect an information on a first arriving path, the information includes a time or a direction for the first arriving path; and a channel state analyzer configured to estimate a LOS channel condition to determine a channel state information describing the condition of the first arriving path.
According to another embodiment, a communication system may have at least a user equipment and a TRPTRP or at least two user equipments having an inventive transceiver.
According to another embodiment, a method for signaling the LOS channel condition within an inventive communication system may have the steps of (DL Procedure): NW checks UE capability for phase processing or channel state detection; Configure the UE to receive one or more PRS resource for phase processing or channel state detection; Provide UE with the PRS configuration and/or indicate resources to process coherently; UE process the PRS resources and/or report the phase measurements for multiple snapshots or the Movement information w.r.t. the PRS measurements or a LOS/NLOS/OLOS condition based on the PRS measurements within a TRP resource set.
According to another embodiment, a method for signaling the LOS channel condition within an inventive communication system may have the steps of (UL Procedure): NW checks UE capability for phase transmission; Configure the UE with SRS for phase tracking configuration; Indicate to the UE that SRS resource is configured for coherent processing; UE report the movement information w.r.t. the measurements and/or TRP process the SRS resources and/or Report the phase measurements to the LMF and/or report a LOS/NLOS/OLOS condition based on the SRS measurements within a SRS resource set and/or LMF detects the LOS/NLOS condition.
According to another embodiment, a method for signaling the LOS channel condition within an inventive communication system may have the steps of (DL- UL Procedure (RTT)): NW checks UE capability for coherent SRS resource transmission; NW checks UE capability for phase processing or channel state detection; Configure the UE with SRS for phase tracking configuration; Indicate to the UE that SRS resource is configured for coherent processing; Configure the UE to receive one or more PRS resource for phase processing or channel state detection; Provide UE with the PRS configuration and indicate resources to process coherently; UE report the Movement information w.r.t. the measurements and/or UE process the PRS resources and/or Report the phase measurements for multiple snapshots and/or Report the Movement information w.r.t. the PRS measurements and/or Report a LOS/NLOS/OLOS condition based on the PRS measurements within a TRP resource set and/or TRP process the SRS resources and/or Report the phase measurements to the LMF and/or Report a LOS/NLOS/OLOS condition based on the SRS measurements within a SRS resource set and/or LMF detects the LOS/NLOS condition.
According to another embodiment, a method for signaling the LOS channel condition within an inventive communication system may have the steps of (Sidelink Procedure (RTT)): NW checks UE(s) capability for coherent sidelink-PRS resource transmission; NW checks UE(s) capability for phase processing or channel state detection; Configure the UE (or UEs) with sidelink-PRS for phase tracking configuration; Indicate to the UE that sidelink-PRS resource is configured for coherent processing; Configure the UE to receive one or more sidelink-PRS resource for phase processing or channel state detection; Provide UE with the sidelink-PRS configuration and indicate resources to processed coherently; One or multiple UEs reports the Movement information w.r.t. the measurements and/or UE process the sidelink-PRS resources and/or Report the phase measurements for multiple snapshots and/or Report the Movement information w.r.t. the PRS measurements and/or report a LOS/NLOS/OLOS condition based on the sidelink-PRS measurements within a second UE and/or LMF detects the LOS/NLOS condition.
According to another embodiment, a method for performing a channel state analysis may have the steps of: receiving a receive signal or the plurality of receive signals to be used for position determination over multiple points of time; performing a measurements to detect an information on a first arriving path, advantageously a time or a direction for a first arriving path; and estimating a LOS channel condition to determine a channel state information describing the condition of the FAP.
Another embodiment may have a non-transitory digital storage medium having a computer program stored thereon to perform the method for performing a channel state analysis having the steps of: receiving a receive signal or the plurality of receive signals to be used for position determination over multiple points of time; performing a measurements to detect an information on a first arriving path, advantageously a time or a direction for a first arriving path; and estimating a LOS channel condition to determine a channel state information describing the condition of the FAP, when said computer program is run by a computer.
Another embodiment may have a transceiver configured to receive a receive signal and having a position/motion detection entity configured to determine a position/motion of the transceiver or a position/motion of another transceiver, wherein the position/motion detection entity uses for the determination of the position/motion a channel state information classifying the receive signal as LOS state, NLOS state, OLOS state, or MPC state.
According to another embdodiment, a communication system may have at least a user equipment and a TRP or at least two user equipments having an above-mentioned transceiver.
According to another embodiment, a method for position/motion detection may have the steps of: receiving a receive signal and for a position/motion detection entity; determining a position/motion of the transceiver or a position/motion of another transceiver by use of a channel state information classifying the receive signal as LOS state, NLOS state, OLOS state, or MPC state.
Another embodiment may have a non-transitory digital storage medium having a computer program stored thereon to perform the method for position/motion detection, the method having the steps of: receiving a receive signal and for a position/motion detection entity; determining a position/motion of the transceiver or a position/motion of another transceiver by use of a channel state information classifying the receive signal as LOS state, NLOS state, OLOS state, or MPC state, when said computer program is run by a computer.
Embodiments provide a transceiver for receiving a receive signal (plurality of RSs) to be used for position determination over multiple points of time, the transceiver comprising a measurement unit and a channel state analyzer. The measurement unit is configured to perform a measurements to detect an information on a first arriving path (FAP), advantageously a time or a direction for a first arriving path (FAP). The channel state analyzer is configured to estimate a LOS channel condition to determine a channel state information describing the condition of the FAP.
According to embodiments, the channel state analyzer may be configured to analyze a correlation profile of the receive signal (plurality of RSs), wherein the analyzing comprises:
According to embodiments, the receive signal (plurality of RSs) comprises multiple frames or is a periodic signal or a semi-persistent signal or a signal with a known time offset; additionally or alternatively the channel state analyzer may be configured to perform the evaluation for further points of time.
According to embodiments, the multi-points of time are defined by at least one out of the group comprising the following:
According to embodiments, the receive signal (plurality of RSs) is received along a movement of the transceiver for receiving the receive signal (plurality of RSs) over the first, second and third point of time or along a movement of a transmitter outputting the receive signal (plurality of RSs) over the first, second and third point of time.
According to embodiments, the channel state analyzer may be configured to classify the receive signal (plurality of RSs) as LOS state, NLOS state or to classify the receive signal (plurality of RSs) as LOS state, NLOS state, OLOS state; and/or to classify the receive signal (plurality of RSs) as LOS state, NLOS state or MPC state.
According to embodiments, the information to be extracted refers to at least one of the group comprising:
According to embodiments, the channel state analyzer may be configured to perform a phase measurement of the receive signal (plurality of RSs) received at the first point of time, second point of time and third point of time in order to extract the first, second and third information.
According to embodiments, the channel state analyzer is configured to perform a phase measurement to determine an angle of departure of a transmission signal and/or to determine an angle of arrival of the receive signal.
According to embodiments, a proportional course of a phase of the receive signal (plurality of RSs) over the first, second and third point of time may indicate to an LOS state; a discontinuous course of the phase of the receive signal (plurality of RSs) over the first, second and third point of time may indicate an NLOS state; wherein a combination of a proportional course and a discontinuous course of a phase of the receive signal (plurality of RSs) over the first, second and third point of time may indicate an OLOS state.
According to embodiments, the channel state analyzer is configured to account the phase measurement with directional information derived from the Angle of Arrival and/or Angle of Departure and/or antenna beam characteristics.
According to embodiments, the phase measurements can comprise either one or a combination of the phase measurements on different time intervals, phase measurements at different frequencies or bandwidth parts, or phase measurements between different transmitter units or phase measurements between different receiver units or phase measurements between the different antenna ports of the same transmitter or receiver units.
According to embodiments, the channel state analyzer is configured to detect a first arriving path and/ a time-position of the first arriving path at a first, second and third point of time.
According to embodiments, the transceiver comprises a position determination entity configured to determine a position information based on an information regarding the first arriving path of the receive signal (plurality of RSs) taking into account the channel state information.
According to embodiments, the transceiver comprises a reporting entity configured to output a report on the channel state information to a second transceiver; alternatively, the transceiver comprises a transmitter configured to output a report on the channel state information to a network entity (LMF) and wherein the report comprises an information out of the following:
This means according to embodiments, that a support reporting (e.g. to the LMF) is enabled. The reporting may include LoS/NLoS indicators for DL, UL, and DL+UL positioning measurements taken at both UE and TRP at least for UE assisted positioning.
According to embodiments, one of the following options (or combinations of the following options) for LoS/NLoS indicators may be supported:
According to embodiments, the channel state analyzer is configured to analyze the receive signal (plurality of RSs) with regard to a confidence of the channel state and/or with regard to a quality of the receive signal (plurality of RSs) ; a high amplitude and/or a sharp lobe may indicate a high quality of the receive signal (plurality of RSs) ; a low amount of information for the correlation profile out of a general trend of all information for the correlation profile may indicate a high confidence of the channel state.
According to embodiments, the channel state information is used for the measuring out of the group:
According to embodiments, the reporting entity is configured by a higher layer (RRC, LPP, NLPPA or DCI) to report a channel state.
According to embodiments, the channel state analyzer is configured to be externally triggered, wherein the triggering comprises an exchange of the following information:
According to embodiments, the channel state analyzer is configured to conFig. the transmitter transmitting the receive signal with two or more resources with different configurations, where the configurations are out the group comprising:
According to embodiments, the channel state analyzer is configured to configure the transmitter transmitting the receive signal with two or more resources and indicating which resources may be coherently processed; additionally or alternatively the channel state analyzer is configured to configure the transmitter transmitting the receive signal comprising multiple signals or to receive the receive signal comprising multiple signals for a channel state detection mode with the same spatial domain transmission filter.
According to embodiments, the channel state analyzer is configured to trigger a transmission of a receive signal (plurality of RSs) comprising at least two coherent signals (coherent bands).
According to embodiments, the transceiver comprises a position / motion detection entity.
According to embodiments, the position/motion detection entity is configured to determine a motion of the transceiver and/or a direction of the motion of the transceiver using an internal sensor, advantageosuly an IMU sensor. In accordance with an embodiment, the position/motion detection is derived at least on one of the following reference signals :
Note the one or more recive signals as discussed above can be used as reference signal. This means that the receive signal forms according to embodiments a reference signal.
According to embodiments, the position/motion detection entity is configured to determine the motion and/or direction upon LMF requests; alternatively or additionally the LMF triggers the transceiver to report the motion / direction information to a given time interval in relation to a transmitted SRS or a received PRS; alternatively or additionally the motion and/or direction information comprises a displacement information Δd.
According to embodiments, the position/motion detection energy is configured to determine a position at a first point of time and at a second point of time and to calculate the displacement Δd based on the equation Δd = c (τB - τA) = cΔτ.
According to embodiments, wherein the channel state analyzer analyzes the channel state based on the formula using
wherein ε is a random error.
According to embodiments, wherein the position/motion detection entity is configured to use MPC, in case of NLOS state (as virtual TRP from the point of view of the UE).
Another embodiment provides method for performing a channel state analysis comprising the steps:
Note, the estimating may comprise an analyzing a correlation profile of a receive signal (plurality of RSs) to be used for a position determination over multiple points of time, comprising the sub steps of
Another embodiment provides a computer program having a program code for performing, when running on a computer, the above method.
Another embodiment provides a Transceiver configured to receive a receive signal and comprising a position/motion detection entity configured to determine a position/motion of the transceiver or a position/motion of another transceiver, wherein the position/motion detection entity uses for the determination of the position/motion a channel state information classifying the receive signal as LOS state, NLOS state, OLOS state, or MPC state.
According to embodiments, a user equipment (downlink measurements) comprises the above transceiver. According to embodiments, a TRP (uplink measurements) comprises the above transceiver. According to embodiments, a reference device (uplink and/or downlink measurements) comprises the above transceiver. According to embodiments, a user equipment (sidelink measurements) communicating with another user equipment comprises the above transceiver.
Another embodiment provides a communication system comprising at least a user equipment and a TRP or at least two user equipments as defined before. Here, one of the entities may transmit the receive signal (plurality of RSs).
Another embodiment provides method for position/motion detection, comprising:
According to embodiments, the channel analyzer is configured to determine the LOS or NLOS channel state condition from a complex correlation at a measurement instant based on the following method (performed by the channel analyzer), the method comprising:
According to embodiments, the evaluation can represent a complex correlation area; additionally or alternatively, the evaluation represent a difference between a reference complex correlation and a reference complex correlation; Note, the FAP from a NLOS tends to vary rapidly due behavior of the multipath with from large and changing relfection surfaces. The complex correlation channel analyzer can evaluate the complex correlation characteristics at multiple time instants from multiple measurements and estimate the LOS, NLOS, or LOS state from the multiple measurements. According to embodiments, the evaluation on the more evaluation at multiple time instants.
Another embodiment provides a corresponding computer program having a program code for performing, when running on a computer, said method.
Embodiments of the present invention will be detailed subsequently referring to the appended drawings, in which:
to illustrate embodiments;
Before discussingsummar the invention, conventional technology will be discussed, where the recognition of drawbacks is part of the invention.
For LTE the accuracy requirements where below 50 meters. The channel state between the UE and Base station was for most of the deployment scenarios was in NLOS condition. With 5G, positioning was introduced in Release 16 targetting much higher accuracy levels (<20 cm). However supporting a channel state identification in 3GPP is not supported up to yet.
The current standard does not enable a mechanism for configuring an entity to perform or report complex-values (real-lm) for the correlation information.
The current standard does not enable a mechanism for configuring an entity to perform or report complex-values (real-lm) for the correlation information.
According to embodiments, it is possible to determine LOS/NLOS reception based on the phase measurements
Bellow, a possible definition of LOS, NLOS and OLOS in addition to the multipath will be given.
The multipath components in a LOS, OLOS or NLOS can be seen as result of either one or a combination of more than one of the following:
Narrow Surface reflections will be discussed with respect to
Reflection from edges or diffraction (knife edge obstacle), OLOS (obstructed LOS, cf.
Similar channel characteristics (RMS Delay Spread and Shadow Fading) Based on the above, the channel characterization enables the responsible entity to classify a Tx-Rx link as LOS, NLOS or OLOS. The MPC types gives an additional indication on the classified quality and uncertainty as well.
An example is illustrated by
A UE 10, as it is illustrated by
For example, a correlation profile of the receive signal or the plurality of receive signals (RSs) may be used. According to an embodiment, the analyzer 10a performs the analysis by attracting a first information for the correlation profile at a first point of time, a second information for the correlation profile at a second point of time and a third information for the correlation profile at a third point of time. The channel state information is then determined based on the relationship of the first, second and third information with respect to each other.
The processing entity 10a responsible for the classification can use one or more of the information to determine the FAP LOS condition. The processing entity can apply machine learning approach based on this input information.
According to embodiments, reporting channel state information can be performed: Based on this information derived the UE (as a measurement entity) can either report the measurements to a second entity (for LMF) or the UE can use this information to determine a LOS/OLOS/NLOS reception.
For this case the UE (or/and TRP) reports the LMF the channel state:
The reporting entity can associate the channel state reporting with the links used for the measurement performed for example RSTD for DL-TDOA and OTDOA, RTT for multi-RTT, RTOA of UTDOA, and DOA or AOA for directional based methods. The reporting provides the positioning entity (LMF) the channel state information with time information: systemFrameNumber and HyperSFN as defined in TS 36.331 and TS 38.331.
For TDOA measurement reporting like RSTD (involving two-TRP links per measurement), the reported channel state indicates the channel state for one link where the reporting entity can be configured to report the reference link separately. To reduce signaling overhead, the reporting entity can be configured by higher layers (RRC [2], LPP [1], MAC-CE) to configure a UE to report a change in state or NRPPa [3] to configure a TRP. In this case the reporting entity reports the channel state once the LOS/NLOS/OLOS changes. The configuration message provides the reporting entity with instruction on the reporting which can optionally configure triggering the Occurrence field.
Below a definition of the measurement and reporting entity will be given: For a downlink scenario the UE receives the RS signal transmitted from one or more TRPs and performs the measurements and is hence the measurement entity. For an Uplink scenario the TRP receives the RS signal transmitted from the UE and performs the measurements and is hence the measurement entity. For an Uplink-Downlink scenario both the UE and TRP are the measurement units. For sidelink, one or two communication UEs are the measurement units.
According to embodiments, it is possible to determine the complex valued FAP. For the same measurement from
Classical methods analyze the correlation profile of the correlation magnitude in the time plane. A receiver receives multiple reflections from the same transmitted signal with different propagation times. For frequency band limited signals, the near reflection around the first arrival path might result in variations in amplitude and phase which depends on the power of each path and reception time. The complex correlation and contains additional phase information needed to estimate a channel state condition. Such information is lost when considering the correlation magnitude alone.
Thus, according to further embodiments, the receiver/measurement unit is configured to analyze a correlation profile and/or complex correlation profile with respect to an amplitude and/or a phase.
According to embodiments, phase measurements can be used to detect a LOS/NLOS condition. The measurement entity can perform successive phase measurements on the FAP path on the RSs transmitted on multiple time or frequency instants. The measurement entity can make a hypothesis whether the link corresponds to a channel state (NLOS, OLOS or LOS) by comparing the behavior of the measurements and the expectation of each of the channel state.
For the same example scenario,
Signaling 3GPP:To enable the procedure related to phase processing
When the UE is configured by the higher layer parameter SRS-for-Positioning or SRS and if the higher layer parameter within a resource or resource set indicates phase or coherent configuration: then the UE shall transmit the target SRS resource with the same spatial domain transmission filter over the configured resource.
The complex correlation profile provides additional information on the correlation lob (area under a peak) or peak magnitude. In general a higher Bandwidth enables the measurement unit to better resolve the channel response on the FAP. For the phase processing a higher update rate is needed to accommodate the frequency offset and the movement. Hence the NW can configure one or more resources with a high periodicity and low bandwidth for phase processing and configuring a wide bandwidth with lower periodicity for other resources:
In the presence of a movement profile along a track with unknown direction of movement and regular RS measurements (i.e., measurements made on periodic or semi-persistent RS along the track), for the determination of Δd (extra travelled distance between two successive measurements) two methods according to two embodiments can be distinguished.
Motion information related to the movement profile of a mobile UE can be obtained upon LMF request. Such information include, terminal speed and orientation of UE, and distance traveled (i.e., displacement) between two successive RS measurements. The difference a radio wave is traveled after d m (i.e.,Δd) can then be calculated in the following steps:
The UE orientation and the angle θ determined between the tracks points A, B and the TRP are determined using the Driving direction and Displacement information can also be estimated based on the information provided by internal sensors like IMU. The driving direction can be estimated with respect to a previous measurement point.
To enable this option, the LMF triggers the UE to report the Motion-Information (provided in LPP [1]) to a given time interval in relation to a transmitted SRS or a received PRS (or a reported measurement like RSTD). This LMF can request from the UE a startTime to associate the displacement information reported to the measurements used.
Once Δd is known, the phase difference between the two (coherent) radio signals received at point A and point B (i.e.,Δφ) is calculated using
where ε is a random error that account for frequency jitter. The phase difference is used to recognize state change (i.e., LOS/NLOS). In case the LOS path is blocked or obstructed, a NLOS scattering cluster (with multiple subpaths) can be considered as a virtual TRP 13 from the point of view of the UE as seen in
Below, different approaches according to different embodiments will be used. For example, a procedure based on PLOS or multiple frequency bands, a downlink procedure, a downlink-uplink procedure or a sidelink procedure may be used. Below the basic steps for these procedures will be discussed, when it is clear that each procedure represents its own embodiment. Some of the steps discussed in the context of the procedures are marked as optional steps or as conditional steps.
Assuming that coherence is maintained between two PRS resources (i.e., PRS are sent from the same TRP using the same local oscillator), then the UE can be indicated by the TRP that the two PRS are coherent. The UE uses this information to identify the phase difference between these two measurements. The relative phase difference with respect to two different measurements can be formulated as:
where f(t) is the frequency offset due to the oscillator impact and ε1 and ε2 are the a random errors that account for measurement noise at frequency 1 and 2.
According to embodiments, the NW (gNB) may configure the UE to transmit multiple coherent resources]
In order to enable the channel state analyzer to estimate the channel state, the channel analyzer may according to embodiments derive one or more channel parameters and compare these parameters with an expected function (such as a distribution function) or a value of this channel parameter, or a combination of multiple parameters. The expected function or value is dependent on channel state (LOS, NLOS and OLOS) and the measurement or reference channel. Examples on the measurement or reference channel can be Urban Micro, Urban Macro, Industry factory Dense, Industry factory sparse, indoor office open, indoor office mixed, outdoor to indoor, satellite open sky ...
In one embodiment, the channel analyzer receives from the network a message including information to enable estimating the channel state.
In a first option, the information message includes a channel model indication which the channel analyzer uses as a reference to derive one or more parameters for the channel state estimation. The information can include a channel model indication which in one example is an indication on known channel models such as the channel models (UMi, Uma, InH, InF-DH, InF-SH ... ) in TR 38.901. In another example the channel indication may represent a scenario-defined model which is known or pre-configured to the channel analyzer.
In a second option, the information message includes an one or values of the channel parameters associated with each channel state. In one example the values can be represented with a reference value or/and include values for the distribution function such as the mean, median and standard deviation.
The information message may include an indication of the channel model and one or more specific parameter values which, when signaled, overwrites the default parameter values of the channel model.
Although some aspects of the described concept have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or a device corresponds to a method step or a feature of a method step. Analogously, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus.
Various elements and features of the present invention may be implemented in hardware using analog and/or digital circuits, in software, through the execution of instructions by one or more general purpose or special-purpose processors, or as a combination of hardware and software. For example, embodiments of the present invention may be implemented in the environment of a computer system or another processing system.
The terms “computer program medium” and “computer readable medium” are used to generally refer to tangible storage media such as removable storage units or a hard disk installed in a hard disk drive. These computer program products are means for providing software to the computer system 500. The computer programs, also referred to as computer control logic, are stored in main memory 506 and/or secondary memory 508. Computer programs may also be received via the communications interface 510. The computer program, when executed, enables the computer system 500 to implement the present invention. In particular, the computer program, when executed, enables processor 502 to implement the processes of the present invention, such as any of the methods described herein. Accordingly, such a computer program may represent a controller of the computer system 500. Where the disclosure is implemented using software, the software may be stored in a computer program product and loaded into computer system 500 using a removable storage drive, an interface, like communications interface 510.
The implementation in hardware or in software may be performed using a digital storage medium, for example cloud storage, a floppy disk, a DVD, a Blue-Ray, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective method is performed. Therefore, the digital storage medium may be computer readable.
Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.
Generally, embodiments of the present invention may be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer. The program code may for example be stored on a machine-readable carrier.
Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine-readable carrier. In other words, an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.
A further embodiment of the inventive methods is, therefore, a data carrier (or a digital storage medium, or a computer-readable medium) comprising, recorded thereon, the computer program for performing one of the methods described herein. A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or the sequence of signals may for example be configured to be transferred via a data communication connection, for example via the Internet. A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein. A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.
In some embodiments, a programmable logic device (for example a field programmable gate array) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. Generally, the methods are performed by any hardware apparatus.
While this invention has been described in terms of several advantageous embodiments, there are alterations, permutations, and equivalents, which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and compositions of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention.
Number | Date | Country | Kind |
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20189874.9 | Aug 2020 | EP | regional |
This application is a continuation of copending International Application No. PCT/EP2021/071945, filed Aug. 05, 2021, which is incorporated herein by reference in its entirety, and additionally claims priority from European Application No. EP 20189874.9, filed Aug. 06, 2020, which is also incorporated herein by reference in its entirety.
Number | Date | Country | |
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Parent | PCT/EP2021/071945 | Aug 2021 | WO |
Child | 18164452 | US |