RU2811939C1 - Method for controlling transmission power with emulation of propagation of reference signal used to estimate losses over channel with pre-coding, device implementing its and their variants - Google Patents

Abstract

FIELD: wireless communication.

SUBSTANCE: mentioned technical result is achieved by receiving a channel state information reference signal (CSI-RS), transmitted from the digital ports of the transmitting and receiving antenna unit of the transmitting and receiving point for user equipment located in the served cell; measuring the channel from the digital ports of the transmitting and receiving antenna unit of the transmitting and receiving point based on the mentioned CSI-RS; obtaining a direct indication or approximation of the precoding to be applied by the transceiver point for communication with the user equipment (UE); based on emulating the propagation of a reference signal from a transceiver point (TRP) to the UE over an equivalent channel obtained by applying the obtained precoding or precoding approximation to the measured channel, an RSRP estimate is calculated (S130); determining a PL value based at least in part on the RSRP estimate; and performing uplink transmission on the TRP with the transmit power adjusted based at least in part on the determined PL value.

EFFECT: improving the accuracy of estimating the reference signal receive power (RSRP), determining the propagation loss (PL), and performing power control (PC) without increasing overhead.

24 cl, 8 dwg

Description

Technical field

[0001] The present disclosure relates to the field of communications, namely to methods of communication between a User Equipment (UE) and a Transmit/Receive Point (TRP), and corresponding devices implementing the corresponding methods. These communication methods use emulation of the channel propagation of a reference signal used to estimate the losses required for transmit power control, with pre-coding performed.

State of the art

[0002] The sixth generation (6G) mobile communications system, operating in the high and mid-frequency range (9-13 GHz), will support extremely massive spatial signal coding antenna systems (Extreme Multiple Input Multiple Output, xMIMO) (≥ 1024 antenna elements) with hybrid analog and digital beamforming (BF) at the TRP (eg at the base station, BS) with a large number of antenna ports (≥ 128).

[0003] High gain narrow transmit/receive beamforming offered for 6G by xMIMO technology is considered a very attractive approach to compensate for propagation loss in downlink (DL) and uplink (UL), as well as to enable the use of advanced transmission schemes with multiple MIMO layers.

[0004] For UL transmission, transmit (Tx) Power Control (PC) is used to ensure comparable Power Spectral Density (PSD) of receive (Rx) UL signals from different UEs, as well as to reduce inter-cell interference and reducing UE power consumption. There are two types of uplink PC: standalone PC (also referred to as “open loop” PC), in which the UE itself determines the value of the required transmit power, and non-standalone PC (also referred to as “closed loop” PC), in which the UE uses, for PCs explicitly signaled by TRP transmit power control commands. Since the UL and DL channels are reciprocal, the UL Path Loss (PL) is typically measured at the UE through DL measurements.

Problems/tasks solved by the invention

[0005] To implement PC on the UE, the TRP broadcasts Synchronization Signal/Physical Broadcast Channel (PBCH) blocks. SS/PBCH blocks are used by the UE to synchronize with the network and based on them the UE measures the received power of the reference signal (Reference Signal Received Power, RSRP). To transmit SS/PBCH blocks, TRP uses relatively wide transmission beams (see 1 in Fig. 1 ) so that despite the limitation on the number of transmissions of SS/PBCH blocks in the 3GPP specifications (depending on the frequency used, this number can be 2, 4, 8 , 16, 64), SS/PBCH block transmissions covered the entire area served by a given TRP. Since subsequently, after synchronization of a UE in the network provided by a specific TRP, that TRP will form and use a (narrower) receive beam from a specific UE, a mismatch problem arises between the SS/PBCH transmit beams used on the TRP and the data receive beams from specific UEs. This mismatch, clearly illustrated in Fig. 1 (compare position 1 in FIG. 1 and the right side of this figure), causes the UE to measure RSRP based on the SS/PBCH, subsequently determine the PL value based on the measured RSRP, and perform PC based on the determined PL value will not as accurate as they could be if the reference signal was transmitted from the TRP already from the BF to the specific UE.

[0006] The mismatch problem described above is solved by generating on the TRP and transmitting, for measurement to the UE, a reference signal directly from the BF to a specific UE, i.e. transmission of a given reference signal is pre-coded to a specific UE. The reference signal transmitted in this solution can be the CSI-RS reference signal for Beam Management (BM). However, this solution to the above-described problem of data transmission/reception beam mismatch is characterized by another problem, which consists in a significant increase in overhead costs, since in this case, each UE generates and transmits its own pre-coded reference signal. In such a solution, the overhead increases as a multiple of the number of active UEs in the cell. This problem is also illustrated in FIG. 1 (see position 2). In addition, this solution can additionally apply, as schematically shown in FIG. 1 (see item 2), reducing the transmit power on the DL to meet the maximum effective isotropically radiated power (EIRP) requirements, which again degrades the coherence of the data transmission/reception beams.

[0007] Thus, there is a need in the art for an improved solution that allows the RSRP to be estimated, the PL to be determined, and the PC to be performed more accurately by taking into account the typically present mismatch on the TRP of the transmit/receive data paths in the situations described above, without increasing the overhead.

The essence of the invention (Tools for solving problems/tasks)

[0008] With the present invention, the above and other problems, although not explicitly stated, but related to or resulting from the above problems in the prior art are solved or at least mitigated. The above and additional problems/objectives and the corresponding beneficial technical effects achieved will be further discussed in the following description in the context of specific features of the technical solution proposed in this application.

[0009] In a first aspect of the present invention, a UE-implemented method of communicating with a TRP is provided, the method including: receiving CSI-RS transmitted from digital ports of a transceiver antenna unit of a transceiver point for those in a served cell user equipment; measuring the channel from the digital ports of the transmitting and receiving antenna unit of the transmitting and receiving point based on the mentioned CSI-RS; receiving a direct indication or approximation of the precoding to be applied by the transceiver point to communicate with the UE; based on emulating the propagation of a reference signal from the TRP to the UE over an equivalent channel obtained by applying the obtained precoding or precoding approximation to the measured channel, RSRP is calculated; determining a PL value based at least in part on the RSRP estimate; and performing UL transmission to the TRP with transmission power adjusted based at least in part on the determined PL value.

[0010] The method according to the first aspect allows the UE to emulate, based on the measurement of a cell-specific (i.e., common/same for all UEs) reference signal, propagation of the reference signal over the channel as if the reference signal would be pre-encoded for transmission to a given UE (i.e. this reference signal would be UE-specific, i.e. a separate reference signal specifically for this UE). The precoding is obtained either by direct instruction from the TRP or by an approximation based on the assumption that, in general terms, the TRP will perform beamforming to communicate with a given UE in the most optimal manner. Thus, the technical solution stated in the attached claims makes it possible to estimate RSRP, determine PL and perform PC more accurately by taking into account the mismatch usually present in the situations described above on the TRP of data transmission/reception beams, without increasing overhead costs. The above favorable technical effects are achieved by a combination of features of each independent claim of the attached claims. The overhead is not increased because instead of a pre-coded reference signal, also referred to here as a UE-specific reference signal, CSI-RS transmitted from the digital ports of the TRP antenna unit, which is a cell-specific reference signal, is used. signal, i.e. a reference signal that is not subject to any precoding. Thus, in the first aspect of the present invention, the CSI-RS received at the UE is emitted by the CSI-RS TRP, which is not pre-coded.

[0011] In a possible implementation of the first aspect of the present invention, the method further comprises a step in which a direct indication of said precoding is received from the TRP, or a step in which a precoding provided by a precoder determined based on a predetermined codebook is used as precoding. In this case, the precoder is indicated or determined by a precoding matrix selected from a predefined codebook and signaled by a Precoding Matrix Indicator (PMI), and/or a precoding rank, signaled by a Rank Indicator (RI).

[0012] In a possible implementation of the first aspect of the present invention, when a direct indication of said precoding is received from the TRP, a PMI and/or RI indicating this precoding is received from the TRP in the Downlink Control Information (DCI), in Medium Access Control (MAC) signaling, or Radio Resource Control (RRC) signaling.

[0013] In a possible implementation of the first aspect of the present invention depending on the configuration of the RRC and/or UE capabilities as predefined codebook use a Type 1 codebook or an enhanced Type 2 codebook.

[0014] In a possible implementation of the first aspect of the present invention depending on the configuration of the RRC and/or UE capabilities as precoding rank, use Rank 1 or Rank 2.

[0015] In a possible implementation of the first aspect of the present invention, channel measurement from the digital ports of the transmit/receive antenna unit of the transmit/receive point is performed on a single occurrence basis (“single occasion”) of CSI-RS.

[0016] In a possible implementation of the first aspect of the present invention, configuring the UE to perform one or more, or all of the steps of receiving CSI-RS transmitted from the digital ports of the transmit/receive antenna unit of the transmit/receive point for user equipments located in the served cell; measuring the channel from the digital ports of the transmitting and receiving antenna unit of the transmitting and receiving point based on the mentioned CSI-RS; obtaining a direct indication or approximation of the precoding to be applied by the transceiver point to communicate with said UE; based on emulating the propagation of a reference signal from the TRP to the UE over an equivalent channel obtained by applying the obtained precoding or precoding approximation to the measured channel, calculating an RSRP estimate; determining a PL value based at least in part on the RSRP estimate; and performing UL transmission on the TRP with transmission power adjusted based at least in part on the determined PL value via RRC signaling. In another possible implementation of the first aspect of the present invention, these steps are configured to be repeated periodically.

[0017] In a possible implementation of the first aspect of the present invention, an uplink transmission on a TRP is a transmission of one or more of: a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel , PUCCH), Sounding Reference Signal (SRS), Physical Random Access Channel (PRACH).

[0018] In a second aspect of the present invention, there is provided a UE comprising a transceiver antenna unit and a processor configured to implement the method of the first aspect of the present invention or any possible implementation of the first aspect of the present invention.

[0019] In a third aspect of the present invention, there is provided a storage medium storing processor-executable instructions that, when executed by a processor of a device equipped with a transceiver antenna unit, perform the method of the first aspect of the present invention or any possible implementation of the first aspect of the present invention.

[0020] In a fourth aspect of the present invention, a TRP-implemented method of communicating with a UE is provided, the method including: generating a CSI-RS to be transmitted from digital ports of a TRP transceiver antenna unit for user equipments located in a served cell ; emit the generated CSI-RS without its preliminary encoding on the air; and receiving an uplink transmission from the UE with a transmit power adjusted based at least in part on a PL value determined based at least in part on an RSRP estimate calculated based on emulating reference signal propagation over an equivalent channel received by applying to the measured channel the precoding actually used or an approximation of the precoding used by the transceiver point to communicate with the UE, the measured channel being obtained from a measurement in the single occurrence channel of the emitted CSI-RS used between the TRP and the UE. In a possible implementation of the fourth aspect of the present invention, the CSI-RS is a CSI-RS broadcast periodically, semi-periodically, or aperiodically.

[0021] In a possible implementation of the fourth aspect of the present invention, the method further comprises directly transmitting an indication of said precoding to the UE. Here, the precoder is indicated by a precoding matrix selected from a predefined codebook and signaled by PMI, and/or a precoding rank signaled by RI.

[0022] In a possible implementation of the fourth aspect of the present invention, the indication of said precoding includes a PMI, and/or a precoding RI. Moreover, when directly indicating said precoding is transmitted to the UE, PMI and RI specifying the corresponding precoder providing such precoding are transmitted to the UE in DCI, in MAC signaling, or in RRC signaling.

[0023] In a possible implementation of the fourth aspect of the present invention, the precoding matrix is selected from a predefined codebook, which, depending on the RRC configuration and/or UE capabilities, use a Type 1 codebook or an enhanced Type 2 codebook.

[0024] In a possible implementation of the fourth aspect of the present invention, depending on the configuration of the RRC and/or UE capabilities as precoding rank, use Rank 1 or Rank 2.

[0025] In a possible implementation of the fourth aspect of the present invention, the method further comprises the step of the TRP configuring, using RRC signaling, the UE to perform one or more, or all of the following steps: receiving CSI-RS transmitted from the digital ports transmitting and receiving antenna unit of the receiving and transmitting point for user equipment located in the served cell; measuring the channel from the digital ports of the transmitting and receiving antenna unit of the transmitting and receiving point based on the mentioned CSI-RS; receiving a direct indication or approximation of the precoding to be applied by the transceiver point to communicate with the UE; based on emulating the propagation of a reference signal from the TRP to the UE over an equivalent channel obtained by applying the obtained precoding or precoding approximation to the measured channel, RSRP is calculated; determining a PL value based at least in part on the RSRP estimate; and performing uplink transmission on the TRP with the transmit power adjusted based at least in part on the determined PL value.

[0026] In a possible implementation of the fourth aspect of the present invention, the steps are: generating a CSI-RS to be transmitted from the digital ports of the TRP transceiver antenna unit to user equipment located in the served cell; radiation of the generated CSI-RS without its preliminary encoding on the air; and performing reception of an uplink transmission from the UE with a transmit power adjusted based at least in part on a PL value determined based at least in part on an RSRP estimate calculated based on emulating propagation of a reference signal over an equivalent channel received by applying to the actual measured channel directly the specified precoding or approximation of this precoding used by the given transceiver point for communication with the said UE, wherein the measured channel is obtained from a measurement in the single occurrence channel of the emitted CSI-RS used between the given TRP and the UE, configure on TRPs so that they repeat periodically.

[0027] In a possible implementation of the fourth aspect of the present invention, the received uplink transmission from the UE is a transmission of one or more of: PUSCH, PUCCH, SRS, PRACH.

[0028] In a fifth aspect of the present invention, there is provided a TRP comprising a transceiver antenna unit and a processor configured to implement the method of the fourth aspect of the present invention or any possible implementation of the fourth aspect of the present invention.

[0029] In a sixth aspect of the present invention, there is provided a storage medium storing processor-executable instructions that, when executed by a processor of a device equipped with a transceiver antenna unit, perform the method of the fourth aspect of the present invention or any possible implementation of the fourth aspect of the present invention.

[0030] In a seventh aspect of the present invention, there is provided a communication system comprising one or more TRPs of the fifth aspect of the present invention or any possible implementation of the fifth aspect of the present invention and one or more UEs of the second aspect of the present invention or any possible implementation of the second aspect of the present invention .

Brief description of drawings

[FIG. 1] Fig. 1 schematically illustrates problems encountered in the prior art.

[FIG. 2] Fig. 2 is a schematic diagram of flows of operations performed by a UE (right side of the figure) and performed by a TRP (left side of the figure) to implement communication between them according to an embodiment based on the first and fourth aspects of the present invention, respectively.

[FIG. 3] Fig. 3 is a schematic representation of an array of two-dimensional (2D) discrete Fourier transform (DFT) beamforming vectors in a codebook precoding matrix structure that, in accordance with embodiments of the present invention, is reported in direct indication from the TRP or approximated to the UE .

[FIG. 4] Fig. 4 is a schematic diagram of a transmit/receive beam used on a TRP after performing BF on a specific UE and approximated by the UE to be taken into account when calculating the RSRP estimate and determining the PL according to an embodiment of the present invention.

[FIG. 5] Fig. 5 is a schematic comparison of SS/PBCH and CSI-RS in terms of the number of ports used in the TRP to transmit said reference signals, as well as the time and frequency resources occupied by transmissions of said reference signals.

[FIG. 6] Fig. 6 illustrates a schematic diagram of a UE according to the second aspect of the present invention, which is configured to implement a communication method according to the first aspect of the present invention.

[FIG. 7] Fig. 7 illustrates a schematic diagram of a TRP according to the fifth aspect of the present invention, which is configured to implement a communication method according to the fourth aspect of the present invention.

[FIG. 8] Fig. 8 illustrates a schematic diagram of a communication system according to a seventh aspect of the present invention.

Detailed Description of Embodiments

[0031] FIG. 2 is a schematic diagram of flows of operations performed by a UE (right side of the figure) and performed by a TRP (left side of the figure) to implement communication between them according to an embodiment based on the first and fourth aspects of the present invention, respectively.

[0032] The communication method performed on the TRP begins and proceeds to the execution of the steps in which S200 CSI-RS is generated, to be transmitted from the digital ports of the transmit-receive antenna unit of the transmit-receiver point to the user equipment located in the served cell, and radiates the generated CSI S210 -RS from the digital ports of the transmitting and receiving antenna unit of the broadcast receiving and transmitting point. CSI-RS is a cell-specific CSI-RS that may be broadcast periodically, semi-periodically or aperiodically. A non-limiting example of such a CSI-RS is the signal used for channel state feedback (CSI feedback). CSI-RS emissions are conducted on predefined time-frequency resources that the UE is aware of in advance or that the UE can output according to 3GPP specifications. Since the CSI-RS is cell-wide, it is the same for all UEs sensing it in the cell. Thus, generating and emitting this CSI-RS in steps S200 and S210 does not add overhead since any pre-coding of the CSI-RS transmission to a specific UE is not performed.

[0033] In an embodiment, the CSI-RS is configured to be transmitted from part or all of the digital ports of the TRP antenna unit. For xMIMO technology that uses 128 or 256 digital ports, it is preferable for the TRP to transmit CSI-RS from all 128 digital ports or all 256 digital ports at a time. However, CSI-RS emission should not be limited to emission using all available digital ports, since in other embodiments it is possible to transmit CSI-RS first from a portion (½, ⅓, ¼, ¾, etc.) of the available digital ports, and then, one or more times, from the remainder of the available digital ports. The structure of the CSI-RS generated in step S200, emitted in step S210 and subsequently received/processed by the UE may correspond to, but is not limited to, the structure used in 5G NR CSI-RS, see for example section 8.4.1.5 of the TS specification 38.211 (v.17.5.0).

[0034] The UE's communication method with said TRP begins and proceeds to step S100, which receives CSI-RS emitted over the air and transmitted from the digital ports of the transceiver antenna unit of said TRP for user equipments located in the served cell, and step S110, in which the S110 channel is measured based on the received CSI-RS to obtain a channel matrix , Where represents the channel measured from all CSI-RS ports on the i _rx antenna port and the k -th CSI-RS subcarrier. Step S110 may be implemented by any channel measurement method known in the prior art. In non-limiting examples, practical implementation of channel measurement may be performed by comparing the actual received signal passing through the measured channel with the expected signal (for example, the CSI-RS defined in advance in the 3GPP specification) according to one or more criteria, including, but not limited to, the minimum mean square error (Minimum Mean Square Error (MMSE), Maximum Likelihood (ML), etc.

[0035] After channel measurement, the method proceeds to the step of obtaining S120 a direct indication or approximation of the precoding that is to be applied by the transceiver point to communicate with the UE. If the precoding approximation (i.e., beamforming) is performed at this stage, the UE assumes that the TRP will perform the precoding in the most optimal manner. Obtaining S120 of a direct indication or precoding approximation is performed by applying to the measured channel precoder matrices , which is respectively received directly from the TRP or approximated to the UE. Precoder matrix represents a precoder for the i _p -th layer (for Rank 1 i _{p =} 1, for Rank 2 i _{p =} {1, 2), indicating the precoding that will most likely (and most rationally) be applied on the TRP side to communicate with the mentioned U.E. Precoder selection either at the TRP or during said approximation at the UE may be carried out, in non-limiting embodiments, based on various criteria, including, but not limited to, a criterion for maximizing network throughput or a criterion for maximizing the ratio of wanted signal power to the sum of noise powers and interference (Signal-to-Interference-plus-Noise Ratio, SINR). A non-limiting example of a precoder selection implementation may include a low complexity PMI/RI selection scheme described in D. Ogawa, C. Koike, T. Seyama and T. Dateki, “A Low Complexity PMI/RI Selection Scheme in LTE-A Systems,” " 2013 IEEE 77th Vehicular Technology Conference (VTC Spring) , Dresden, Germany, 2013, pp. 1-5, doi: 10.1109/VTCSpring.2013.6691823, but the implementation of precoder selection should not be limited to the mentioned implementation/circuitry, since the disclosed technical solution may use other known circuits and/or criteria.

[0036] It should be noted that the direct precoding indication obtained in step S120 may include both an explicit precoding (eg, in the form of an explicit PMI and/or RI) and an implicit precoding (eg, a codebook type or precoding rank). In the case of an implicit indication, the UE performs precoding determination (ie, precoder selection) itself based on the specified codebook type or rank. For example, the base station reports RI=1, the UE independently searches (based, for example, on the above criteria) for a precoder from the rank 1 codebook; another example, when the base station reports RI=2, the UE independently searches for a precoder from a rank 2 codebook. For example, the base station reports that the codebook type is type 1, the UE independently searches for a precoder from a rank 1 codebook; another example, when the base station reports that the codebook type is type 2 (or enhanced type 2), the UE independently searches for a precoder from the type 2 (or enhanced type 2) codebook. Some of the above non-limiting examples may be combined into one or more other examples of implementation of a given feature.

[0037] As noted above, the precoder is either a precoder defined (approximated) at the UE by a predefined codebook, or a precoder signaled by a direct indication (including implicit) from the TRP. In all cases, the precoder is specified by a precoding matrix selected from a predefined codebook and signaled by PMI, and/or a precoding rank signaled by RI. Because the implementation of certain types of codebooks is optional for the UE, the configuration of the codebook that the UE must use must take into account the UE's ability to support the particular codebook. Therefore, depending on whether the RRC configuration and/or UE capabilities support a particular codebook type or a particular precoding rank, a Type 1 codebook or an enhanced Type 2 codebook is used as the predefined codebook. “enhanced Type 2”), and as precoding rank use Rank 1 or Rank 2. These types of codebooks and precoding ranks are known from the prior art, see, for example, section 5.2.2.2 of the TS 38.214 specification (for the improved Type 2 codebook, see specifically section 5.2.2.2 .5 of the specified specification). In the case where a direct indication of said precoding is received from the TRP, a PMI and/or RI indicating this precoding is received from the TRP in DCI, in MAC signaling, or in RRC signaling.

[0038] In FIG. 3 shows a schematic representation of an array of 2D DFT-based vectors in a precoding matrix structure that define the precoding (beam pattern) communicated in direct indication from the TRP or approximated to the UE. What is shown in this figure should be considered as an example and not as a limitation. The precoding matrix structure shown can be used as an optimal (eg, minimal loss) radiation pattern used to emulate the propagation of a reference signal from the TRP to the UE over the equivalent channel obtained by applying to the channel actually measured over the cell-specific ( cell-specific) CSI-RS, this precoding or an approximation of this precoding, and calculating in step S130 (which will be described in detail below with reference to FIG. 2 ) an RSRP estimate. In a non-limiting example, the selection of a specific precoding matrix (i.e., PMI and RI) may be made from the structure of an existing 5G NR system codebook (see, for example, section 5.2.2.2 of the TS 38.214 specification), which is used for adaptive beamforming in downlink.

[0039] Based on the fact that the precoding weight indicating a particular direction is in the form of a DFT-based vector, the possible precoding matrices consist of orthogonal (N ₁ , N ₂ ) DFT-based vectors for both directions (vertical, horizontal) and, optionally, corresponding DFT-based vectors obtained by resampling the orthogonal DFT-based vectors in the spatial domain according to the values of the parameters O ₁ , O ₂ . The purpose of oversampling, when performed, is to provide a denser array of transmit/receive beams in the spatial domain to fill gaps between adjacent beams that might exist in some cases in the absence of such oversampling.

[0040] Thus, the structure of the precoding matrix based on the predefined codebook has a DFT structure, namely a DFT-based array of N ₁ O ₁ by N ₂ O ₂ 2D vectors (the individual circle in FIG. 3 represents one beam vector that is two-dimensional because it contains both a receive/transmit beam in the vertical plane and a transmit/receive beam in the horizontal plane), where N ₁ represents the number of digital ports in the vertical plane, O ₁ represents the beam sweep pitch in the vertical plane (elevation angle), N ₂ represents the number of digital ports in the horizontal plane, O ₂ represents the beam pitch in the horizontal plane (azimuth). The general functionality of the O ₁ and O ₂ parameters is to define beam sweep steps for beam steering; therefore, the greater the values of the parameters O ₁ and O ₂ , the more the beam can be deployed with a smaller step (i.e., at a smaller angle). In the example shown in FIG. 3 , N ₁₌ 2, N ₂₌ 4; O ₁₌ 4, O ₂₌ 4 (i.e., resampling is performed 4 times in both the vertical and horizontal planes); therefore, the resulting dimension of the precoding matrix structure in the non-limiting example of FIG. 3 is 8x16. Thus, the ray comb that is generated in this example contains a total of 128 2D vectors. However, the above values of the parameters _N1 , _N2 , _O1 , _O2 should not be interpreted as restrictions, since the values of the parameters _N1 , _N2 , _O1 , _O2 may differ from those illustrated in Fig. 3 in actual implementation; in addition, the values of the parameters O ₁ and O ₂ are not necessarily equal to each other. It is clear that for xMIMO technology the values of the parameters N ₁ , N ₂ , O ₁ , O ₂ will be greater than those illustrated in Fig. 3 values of the corresponding parameters, and similar illustrations for xMIMO are not given here to avoid cumbersome figures.

[0041] Each DFT-based 2D vector v is defined as v =vec(w ₁ ⊗ w ₂ ), where vec(A) is an operator that transforms a matrix into a column vector by vertically joining/concatenating the columns of matrix A, w ₁ represents a ray in the vertical plane, w ₂ represents a ray in the horizontal plane, ⊗ denotes the Kronecker product or equivalent product. Since the antenna array has two polarizations, the DFT-based 2D vector v for the other polarization of the antenna array is defined as φv , where the factor φ is chosen to coherently phase the two polarizations together. Described and illustrated with reference to FIG. 3 structure exists in 5G NR systems and is used to adaptively generate beamforming vectors used for downlink transmission.

[0042] Returning toFig. 2, after execution step S120 of obtaining a direct indication or approximation of the precoding to be applied by the transceiver point to communicate with the UE, the method proceeds to step S130 where, based on emulating the propagation of a reference signal from the TRP to the UE over an equivalent channel obtained by applying to on the actual measured channel of the received precoding or precoding approximation, an RSRP estimate is calculated. The RSRP estimate at this stage is obtained in linear form (e.g. in milliwatts (mW)) based on the following expression (1) or based on any functionally equivalent modification of this expression (1) or substitution in this expression (1):

[0043] (Expression 1),

Where

- level 1 reference signal reception power (L1-RSRP) at the UE receiving antenna port, indexed i _rx , with total RSRP ≥ ;

- the number of subcarriers on which CSI-RS was emitted, not subjected to pre-coding;

- channel measured from all CSI-RS ports on the i _rx antenna port and the k -th CSI-RS subcarrier;

- precoder (specified explicitly or implicitly from the TRP, or approximated on the UE) for the i _p th layer and k th subcarrier of the CSI-RS.

[0044] When ports {1, 2} are used to estimate the RSRP based on the received non-precoded CSI-RS, the RSRP estimate is obtained in linear form (e.g., in mW) based on the modified expression (1.1) or based on any equivalent by functionality modification of this expression (1.1) or replacement in this expression (1.1). Modified expression (1.1) differs from the above expression (1) in that linear averaging in it is carried out not only by quantity subcarriers, but also by number ports for RSRP {1, 2}:

[0045] (Modified expression 1.1).

[0046] Performing RSRP estimation as described above with reference to step S130, based on measuring a single occurrence of a CSI-RS that is not pre-coded, allows for RSRP accuracy that is comparable to the RSRP accuracy that could be achieved, but at the expense increased overhead (as described above in the Background Art section) when estimating RSRP from a pre-coded CSI-RS measurement. Thus, it should be clear that, compared to the prior art, the present invention provides improved accuracy of RSRP estimation from non-pre-encoded CSI-RS, does not increase overhead, and introduces only minor complexity to the UE's hardware and software implementation.

[0047] Once the RSRP estimate in step S130 is obtained, the method proceeds to the step of determining S140 a PL value based at least in part on the RSRP estimate. The PL estimate at this stage can be obtained, for example, in decibels (dB), based on the following prior art expression (2) or based on any functionally equivalent modification of this expression (2) or substitution in this expression (2). Units of referenceSignalPower and from Expression (2) should be consistent with each other before proceeding to determine PL at this step S140.

[0048] PL=referenceSignalPower - (Expression 2),

Where

referenceSignalPower - the reference signal power that the TRP has previously reported to the UE, or which is predefined as such in the 3GPP specification, and/or the manner in which the UE is output is predefined in the 3GPP specification as such for various predefined network, UE and/or TRP conditions/configurations , and/or depending on other factors; And

- the RSRP estimate previously obtained at step S130.

[0049] Determining the PL value taking into account the RSRP estimate obtained as described above with reference to step S130, based on the measurement of a single occurrence of a CSI-RS not previously encoded, allows for a PL accuracy that is comparable to the PL accuracy that could be achieve, but at the expense of increased overhead (as described above in the Background Art section), when taking into account the RSRP estimate from the pre-coded CSI-RS measurement in the PL calculation. Thus, it should be clear that, in comparison with the prior art, the present invention provides increased accuracy of PL determination, does not increase overhead costs and leads to only minor complication in the UE hardware and software implementation.

[0050] After determining the PL in step S140, the method proceeds to step S150, which performs uplink transmission to the TRP with transmit power adjusted based at least in part on the determined PL value. The transmission power can be adjusted based on expression (3):

(Expression 3)

Where

- (adjusted) uplink transmit power,

- the maximum allowed transmit power of the UE, this value may be signaled to the UE in a configuration message from the TRP, alternatively, in some cases, this value may be the maximum transmit power of the UE,

- the target power spectral density (Power Spectral Density, PSD) of reception/transmission, pre-configured by TRP and transmitted in the RRC configuration message, for each 15 kHz physical resource block (PRB), subject to full compensation of losses during signal propagation,

μ - numerological correction factor, μ={0, 1, 2, 3, 4} to reflect the separation between individual orthogonal subcarrier frequencies, different from the reference separation of 15 kHz,

- number of RBs allocated for PUSCH,

- propagation loss compensation control coefficient ∈ [0,1], in the specified range the extreme value =0 means no compensation for propagation losses at all, and the other extreme value =1 means full compensation of propagation losses,

- the propagation loss estimate between the TRP and the UE, previously determined in step S140,

- an optional (i.e. may not be present) power offset associated with the selected modulation and coding scheme (MCS), and

- a component of a non-autonomous PC, obtained on the basis of transmission power control commands explicitly signaled from the TRP.

[0051] In a non-limiting example of implementation, power adjustment can be carried out in accordance with the technical solution disclosed in another previously filed application RF 2023119092 (filing date 07.19.2023) of the same applicant (SAMSUNG ELECTRONICS CO., LTD.), entitled “METHOD FOR FREQUENCY -SELECTIVE TRANSMISSION POWER CONTROL, ITS DEVICE IMPLEMENTING, AND THEIR OPTIONS.”

[0052] The uplink transmission to the TRP in step S150 may be, but is not limited to, a Physical Uplink Shared Channel (PUSCH) transmission, a Physical Uplink Control Channel (PUSCH) transmission, PUCCH), transmission of a sounding reference signal (Sounding Reference Signal, SRS), transmission of a physical random access channel (Physical Random Access Channel, PRACH).

[0053] The power adjustment carried out before transmitting step S150 is more accurate because the PL value used in Expression 3 is determined based on the RSRP estimate, which was obtained by measuring the pre-uncoded CSI-RS emulating its reception from the TRP Pre-coding UE. This emulation makes it possible to eliminate the transmission/reception path misalignment described with reference to FIG. 1 , as schematically illustrated in FIG. 4 . As a consequence of the above, the communication efficiency between the TRP and the UE is improved, the overhead does not increase, and the complexity of the UE hardware implementation is negligible.

[0054] After the UE performs the transmission in step S150, the TRP in step S230 receives the uplink transmission from the UE. Moreover, the communication efficiency between the TRP and the UE is improved since the power of this transmission is adjusted based on the PL value determined based on the RSRP estimate calculated based on emulation of the propagation of a reference signal over an equivalent channel obtained by applying the actually used precoding to the measured channel or an approximation of this preliminary encoding used by a given TRP for/when communicating with said UE. The measured channel is obtained from the measurement in the channel actually used between a given TRP and the UE of the single occurrence of emitted CSI-RS that has not been precoded.

[0055] In FIG. 2 does not show that the TRP may additionally transmit Downlink Control Information (DCI) containing a UL grant. By accepting such grant of time-frequency resources before step S150, the UE will transmit in step S150 in the specified time-frequency resources. In addition, in FIG. 2 does not show that the TRP may further request the UE to provide channel state feedback (CSI feedback), in response to receiving such a request, the UE may calculate channel state information (CSI) and report it to the TRP. Such CSI information may include one or more of: PMI, Channel Quality Information (CQI), RI, Layer Indicator (LI). These components of the channel state information may be determined by any method known in the art.

[0056] Additionally, in FIG. 2 does not show that if a TRP uses a limit on the maximum permissible EIRP when transmitting a pre-encoded signal to a particular UE to comply with emitted signal requirements or regulations, the magnitude of this limit can be taken into account additionally for a more accurate approximation (more accurately eliminating the beam mismatch described with reference to Fig. 1 ), a transmit/receive beam that will be used to transmit/receive data after performing a beamforming procedure to a specific UE. To do this, referenceSignalPower in expression 2 can be adjusted by the appropriate amount.

[0057] Next, with reference to FIG. 5 will further describe some features of the non-precoding CSI-RS that is generated on and emitted from the TRP, and subsequently used at the UE for channel sampling, calculating the RSRP estimate with precoding emulation that would be optimal to perform on the TRP for communications. with the given UE, determining PL based on this RSRP estimate, performing UL transmit power adjustment based on the determined PL value. As schematically illustrated in FIG. 5 SS/PBCH blocks are transmitted over the channel from one port of the TRP transmit antenna and occupy a narrow frequency band in the channel. Thus, when SS/PBCHs are used to sample a channel, it is typically necessary to sample the channel across multiple SS/PBCHs located on different frequency resources of the channel being measured, and then average those measurements to obtain an average sample for the entire channel. It is clear that such an approach may not be sufficiently accurate and representative.

[0058] The present invention proposes to use non-precoded CSI-RS, which, unlike the SS/PBCH block, is transmitted on the channel from more (in a non-limiting embodiment, all) TRP transmit antenna ports and occupies more of the channel. frequency band (e.g. 100% of the total available frequency band, typically CSI-RS occupies the entire band). The present inventors obtained fairly accurate channel estimates even based on a single occurrence of CSI-RS. In addition, the structure of the CSI-RS itself is more advantageous in terms of reflecting the characteristics of the measured channel than the structure of the SS/PBCH block, so the use of pre-coded CSI-RS instead of the SS/PBCH itself can improve the accuracy of the UE's (described) above with reference to Fig. 2 ) procedures.

[0059] FIG. 6 illustrates a schematic diagram of a UE 400 according to the second aspect of the present invention, which is configured to implement a communication method according to the first aspect of the present invention by at least including a transceiver antenna unit 405 configured to communicate with a TRP and any other devices within the coverage area of the corresponding cell, and a processor 410 operably coupled to the transmit/receive antenna unit 405 and configured to implement the method of the first aspect of the present invention or any possible implementation of the first aspect of the present invention. User Equipment (UE) may include, but is not limited to, a mobile phone, tablet, laptop, personal computer, wearable electronic device (e.g. glasses, watch), AR/VR headset, Internet of Things (IoT) device, equipment placed in a vehicle or any other electronic device that supports mobile communications. The UE may be called something else, such as user terminal, user device, subscriber device, etc.

[0060] The UE 400 is shown in FIG. 6 in a relatively simplified, schematic form, so this figure does not show all the components actually contained in the UE 400, but only those that make the present invention implemented. As is known, the UE may include other components not shown in the figure, such as a power supply, a battery, various interfaces, input/output means, interconnects, random access and read only memory storing instructions executable by the processor 410 for performing the method of the first aspect of the present invention or any a possible implementation of the first aspect of the present invention, as well as an operating system, etc. The transceiver antenna unit 405 may include a transceiver and an antenna coupled to each other. The antenna can be implemented as a massive or extremely massive MIMO antenna array with a large number of antenna ports that supports hybrid analog and digital beamforming capabilities.

[0061] The processor 410 of the UE 400 may be a central processing unit, a special purpose processor, another processing unit such as a graphics processing unit (GPU), or a combination thereof. Processor 410 may be implemented as a chip, such as a Field-Programmable Gate Array (FPGA), Application-Specific Integrated Circuit (ASIC), System-on-Chip, SoC), etc.

[0062] FIG. 7 illustrates a schematic diagram of a TRP 300 according to the fifth aspect of the present invention, which is configured to implement a communication method according to the fourth aspect of the present invention by at least including a transceiver antenna unit 305 configured to communicate with a UE and any other devices within the coverage area of the corresponding cell, and a processor 310 operably coupled to the transmit/receive antenna unit 305 and configured to implement the method of the fourth aspect of the present invention or any possible implementation of the fourth aspect of the present invention. The Transmission Point (TRP) may be, but is not limited to, a Base Station (BS), an Access Point (AP), or a NodeB, etc.

[0063] TRP 300 is shown in FIG. 7 in a relatively simplified, schematic form, so this figure does not show all the components actually contained in the TRP 300, but only those that make the present invention implemented. As is known, the TRP may contain other components not shown in the figure, such as a power supply, various interfaces, input/output means, interconnects, random access and read only memory storing instructions executable by the processor 310 for executing the method of the fourth aspect of the present invention or any possible implementation. the fourth aspect of the present invention, as well as the operating system, etc. The transceiver antenna unit 305 may include a transceiver and an antenna coupled to each other. The antenna can be implemented as a massive or extremely massive MIMO antenna array with a large number of antenna ports that supports hybrid analog and digital beamforming capabilities.

[0064] The processor 310 of the TRP 300 may be a central processing unit, a special purpose processor, another processing unit such as a graphics processing unit (GPU), or a combination thereof. Processor 310 may be implemented as a chip, such as a Field-Programmable Gate Array (FPGA), Application-Specific Integrated Circuit (ASIC), System-on-Chip, SoC), etc.

[0065] FIG. 8 illustrates a schematic diagram of a communication system 500 according to a seventh aspect of the present invention. The communications system 500 includes one TRP 300 that is installed to serve user equipments 400 in three deployed cells 1, 2, 3. The transmit point 300 may correspond to the TRP 300 that is described in detail above with reference to FIG. 7 , and each user terminal 400 may correspond to a UE 400, which is described in detail above with reference to FIG. 6 , so the TRP 300 and UE 400 are again not described in detail here. The communications system 500 may simultaneously support multiple active radio access technologies (RATs) from, for example, 4G LTE, 5G NR, 6G.

[0066] Specific details shown in FIG. 8 should not be considered as a limitation of the present technology, since the system 500 may have a different architecture and be characterized/illustrated differently, for example, each cell of cell 1, cell 2, cell 3 may have its own TRP 300, the number of UEs 400 in the cells may different from that shown, cells 1, 2, 3 may be one larger cell, the shape and space covered by the cells may be different from those shown, etc.

[0067] The present invention may further be implemented as a storage medium storing processor-executable instructions that, when executed by a processor of a device equipped with a transceiver antenna unit, perform a method of any aspect of the disclosed invention or any possible implementation of the corresponding aspect. A storage medium may be any non-transitory computer readable medium, memory, storage area, storage device, etc., such as, but not limited to, a hard disk drive, optical media, semiconductor media, solid state drive (SSD), or similar to them.

[0068] The technical solutions disclosed herein allow the RSRP to be estimated, the PL to be determined, and the PC to be performed more accurately by taking into account the commonly available prior art mismatch on the TRP of the transmit/receive data paths, without increasing the overhead. Such an assessment, according to the present disclosure, can be made from a single occurrence of a CSI-RS, which increases the accuracy and representativeness of channel sampling on such a signal and, at least in some cases, can help simplify the UE's hardware and software implementation, since the need to perform channel sampling on several reference signals with subsequent averaging of measurements is eliminated.

[0069] Industrial applicability

[0070] The present invention can be used in 3GPP compliant TRP and UE communication networks that support massive MIMO antenna technology with a very large number of digital antenna ports (e.g., ≥ 128), analog/digital single-beam/multi-beam beamforming, and TDD and/or FDD duplex modes. Other applications of the technology disclosed here will become apparent to those of ordinary skill in the art upon reading this detailed description of this application.

[0071] At least one aspect of the disclosed technical solution may be implemented by an AI model. An AI-related function can be performed through persistent memory, RAM, and processor(s) (CPU, GPU, NPU). The processor(s) controls the processing of input data according to a predefined operating rule or artificial intelligence (AI) model stored in read-only memory and main memory. A predefined operating rule or artificial intelligence model is provided through learning. Here, “providing by learning” means that by applying a learning algorithm to a plurality of training data, a predetermined operating rule or AI model with a desired characteristic is created, such as, but not limited to, an AI model to obtain an RSRP estimate (instead of calculating it in step S130). The training data in this case may include measured channel-corresponding RSRP estimate pairs (obtained as described above with reference to step S130). The training may be performed within the device itself using the AI according to an embodiment, and/or may be implemented through a separate server/system. In other examples, an AI model may be created to predict, in the precoding step S120, which is to be applied by the transceiver point to communicate with the UE. The training data in this case may include measured channel-selected precoding pairs.

[0072] The AI model may be a decision tree-based algorithm or consist of multiple neural network layers. Each layer has a plurality of weights and performs the operation of the layer through a calculation based on the result of the calculation in the previous layer and the application of a plurality of weights and other parameter values. Examples of decision tree-based algorithms include random forest, ensemble trees, etc., and examples of neural networks include, but are not limited to, convolutional neural network (CNN), deep neural network (DNN), recurrent neural network (RNN), Restricted Boltzmann Machine (RBM), Deep Belief Network (DBN), Bidirectional Network, Recurrent Deep Neural Network (BRDNN), Generative Adversarial Network (GAN), Transformer Networks, Deep Q-Net and so on.

[0073] A learning algorithm is a method of training a predetermined target device or target function based on a corresponding set of training data that causes, enables, controls, or provides an output of the target device or target function. Examples of learning algorithms include, but are not limited to, supervised learning, unsupervised learning, semi-supervised learning or reinforcement learning, and so on.

[0074] One skilled in the art will appreciate that the various illustrative logical blocks (functional blocks or modules) and steps (operations) used in embodiments of the disclosed technical solution may be implemented by electronic hardware, computer software, or a combination thereof. . Whether functions are implemented using hardware or software depends on the specific application and the design requirements of the overall system. One skilled in the art may employ various methods for implementing the described functions for each particular application, but such implementation should not be considered beyond the scope of the embodiments disclosed herein.

[0075] It should also be noted that the order of the steps of any disclosed method is not strict, because some one or more steps may be rearranged in the actual order of execution and/or combined with another one or more steps, and/or divided into more sub-steps, for example, step S200 may be combined with step S210, step S110 may be combined with step S120, step S130 may be combined with step S140, etc.

[0076] Throughout this application, reference to an element in the singular does not preclude the presence of multiple such elements in the actual implementation of the invention, and, conversely, reference to an element in the plural does not exclude the presence of only one such element in the actual implementation of the invention. Any specific value or range of values stated above should not be interpreted in a limiting sense, but rather such specific value or range of values should be considered to represent the midpoint of the specified larger range, up to approximately 50% on either side of the specified value or range. boundaries of a smaller range.

[0077] While this disclosure has been shown and described with reference to specific embodiments and examples thereof, those skilled in the art will understand that various changes in form and content may be made without departing from the spirit and scope of this disclosure as defined by the appended claims and their equivalents. In other words, the foregoing detailed description is based on specific examples and possible implementations of the present invention, but should not be interpreted to mean that only the explicitly disclosed implementations are feasible. It is intended that any change or substitution that could be made to this disclosure by one of ordinary skill in the art without creative and/or technical contribution shall be within the scope of protection (subject to equivalents) provided by the following claims.

Claims (44)

1. A method of communication with a Transmit-Receive Point (TRP) implemented by User Equipment (UE), the method containing the steps of: receive (S100) a channel state information reference signal (Channel State Information Reference Signal, CSI-RS), transmitted from the digital ports of the transmit-receive antenna unit of the transmit-receive point for user equipment located in the served cell; measuring (S110) the channel from the digital ports of the transmitting and receiving antenna unit of the transmitting and receiving point based on the mentioned CSI-RS; receiving (S120) a direct indication or approximation of the precoding to be applied by the transceiver point for communication with the UE; based on emulating the propagation of the reference signal from the TRP to the UE over the equivalent channel obtained by applying the obtained precoding or precoding approximation to the measured channel, an estimate of the reference signal received power (RSRP) is calculated (S130); determining (S140) a Path Loss (PL) value based at least in part on the RSRP estimate; And performing (S150) uplink transmission to the TRP with transmission power adjusted based at least in part on the determined PL value. 2. The method according to claim 1, in which CSI-RS is not precoded (unprecoded) and is broadcast periodically, semi-periodically or aperiodically. 3. The method according to claim 1, additionally containing: a step where a direct indication of said precoding is received from the TRP, or a step of using the precoding provided by the precoder determined based on the predetermined codebook as precoding, wherein the precoder is indicated or determined by a precoding matrix selected from a predefined codebook and signaled by a Precoding Matrix Indicator (PMI), and/or a precoding rank signaled by a Rank Indicator (RI). 4. The method of claim 3, wherein when a direct indication of said precoding is received from the TRP, a PMI and/or RI indicating the precoding is received from the TRP in Downlink Control Information (DCI), in Medium Access Control (MAC) signaling or Radio Resource Control (RRC) signaling. 5. The method according to claim 3, in which, depending on the RRC configuration and/or UE capabilities as predefined codebook use a Type 1 codebook or an enhanced Type 2 codebook. 6. The method according to claim 3, in which, depending on the RRC configuration and/or UE capabilities as precoding rank, use Rank 1 or Rank 2. 7. The method according to claim 1, wherein the measurement (S110) of the channel from the digital ports of the transmit-receive antenna unit of the transmit-receive point is performed based on a single occurrence of CSI-RS. 8. The method of claim 1, wherein configuring the UE to perform one or more or all of the steps of S100, S110, S120, S130, S140, S150 is performed via RRC signaling. 9. The method according to claim 1, in which steps S100, S110, S120, S130, S140, S150 are repeated periodically. 10. The method of claim 1, wherein the uplink transmission to the TRP is the transmission of one or more of: a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel , PUCCH), Sounding Reference Signal (SRS), Physical Random Access Channel (PRACH). 11. User equipment (UE, 400) comprising a transceiver antenna unit (405) and a processor (410) configured to implement the method according to any one of claims. 1-10. 12. A storage medium storing instructions executable by the processor, which, when executed by the processor of a device equipped with a transceiver antenna unit, ensure execution of the method according to any one of claims. 1-10. 13. A method of communication with user equipment (User Equipment, UE) implemented by a Transmit-Receive Point (TRP), the method comprising the steps of: generating (S200) a channel state information reference signal (Channel State Information Reference Signal, CSI-RS) to be transmitted from the digital ports of the transmitting and receiving antenna unit of the transmitting and receiving point for user equipment located in the served cell; radiate (S210) the generated CSI-RS without its preliminary encoding on the air; And perform (S230) receiving an uplink transmission from the UE with a transmit power adjusted based at least in part on a Path Loss (PL) value determined based at least in part on an estimate of the receive power of the reference signal (Reference Signal Received Power, RSRP), calculated based on the emulation of the propagation of a reference signal over an equivalent channel obtained by applying to the measured channel the actually used precoding or an approximation of this precoding used by a given transceiver point to communicate with the said UE, wherein the measured channel is obtained from the measurement in the single occurrence channel of the emitted CSI-RS used between the given TRP and the UE. 14. The method according to claim 13, in which the CSI-RS is a CSI-RS that is broadcast periodically, semi-periodically or aperiodically. 15. The method according to claim 13, further comprising the step of directly transmitting an indication of said precoding to the UE, wherein the precoder is indicated by a precoding matrix selected from a predefined codebook and signaled by a Precoding Matrix Indicator (PMI), and/or a precoding rank signaled by a Rank Indicator (RI). 16. The method of claim 15, wherein the indication of said precoding includes a Precoding Matrix Indicator (PMI) and/or a Rank Indicator (RI) of the precoding, wherein, when directly indicating said precoding is transmitted to the UE, PMI and RI specifying the corresponding precoder providing such precoding are transmitted to the UE in Downlink Control Information (DCI), in Medium Access Control signaling Access Control (MAC), or in Radio Resource Control (RRC) signaling. 17. The method of claim 16, wherein the precoding matrix is selected from a predefined codebook, which, depending on the RRC configuration and/or UE capabilities, use a Type 1 codebook or an enhanced Type 2 codebook. 18. The method according to claim 16, in which, depending on the RRC configuration and/or UE capabilities as precoding rank, use Rank 1 or Rank 2. 19. The method of claim 13, further comprising the step of the TRP configuring, using RRC signaling, the UE to perform one or more or all of the following steps: receive CSI-RS transmitted from the digital ports of the transmit-receive antenna unit of the transmit-receive point for user equipment located in the served cell; measuring the channel from the digital ports of the transmitting and receiving antenna unit of the transmitting and receiving point based on the mentioned CSI-RS; receiving a direct indication or approximation of the precoding to be applied by the transceiver point to communicate with the UE; based on emulating the propagation of a reference signal from the TRP to the UE over an equivalent channel obtained by applying the obtained precoding or precoding approximation to the measured channel, an RSRP estimate is calculated; performing uplink transmission on the TRP with transmit power adjusted based at least in part on the determined PL value. 20. The method according to claim 13, in which steps S200, S210, S230 are repeated periodically. 21. The method of claim 13, wherein the uplink transmission from the UE is transmission of one or more of: PUSCH, PUCCH, SRS, PRACH. 22. Transmission-reception point (TRP, 300), containing a transmit-receive antenna unit (305) and a processor (310), configured to implement the method according to any one of paragraphs. 13-21. 23. A storage medium storing instructions executable by the processor, which, when executed by the processor of a device equipped with a transceiver antenna unit, ensure execution of the method according to any one of claims. 13-21. 24. A communication system (500) comprising one or more transmit and receive points (TRP, 300) according to claim 22 and one or more user equipment (UE, 400) according to claim 11.