Apparatus and method for communication system

Abstract

The embodiment of the invention relates to a device and a method for a communication system. An apparatus (100) for a communication system (1000), the apparatus (100) comprising at least one processor (102) and at least one memory (104) storing instructions (106) that, when executed by the at least one processor (102), cause the apparatus (100) to: determine (300) a first measurement of a first reference signal associated with a first analog beam used to receive the first reference signal, a second measurement of a second reference signal associated with a second analog beam used to receive the second reference signal is determined (302), and first information characterizing the digital beamformer is determined (304) based on the first measurement and the second measurement.

Description

Technical Field

[0001] Various example embodiments are directed to apparatus for use in a communication system.

[0002] Further embodiments relate to a method for a communication system. Background Art

[0003] A communication system (eg, a wireless communication system) may be used for wireless exchange of information between two or more entities (eg, including one or more terminal devices (eg, user equipment (UE)) and one or more network devices (eg, base stations)).

[0004] In some conventional wireless communication systems, beamforming is applied, for example, to enhance the quality and / or efficiency of radio transmissions. In some conventional methods, beamforming can be used to focus the transmitted signal in a specific direction by combining multiple antenna elements, thereby, for example, improving signal strength, reducing interference, and improving overall system performance.

[0005] In some conventional communication systems, beamforming may be based on reference signals exchanged between devices of the communication system (eg, between a terminal device and a network device).

[0006] In some conventional approaches, analog beamforming is used, which refers to techniques for manipulating the phase and / or amplitude of a signal in the analog domain (e.g., using phase shifters and / or attenuators, etc.) to, for example, control the directionality and / or characteristics of a transmit and / or receive beam.

[0007] In some conventional approaches, digital beamforming is used, which refers to techniques for manipulating the phase and / or amplitude of a signal in the digital domain to, for example, control the directionality and / or characteristics of a transmit and / or receive beam.

[0008] In some conventional methods, hybrid beamforming using a combination of digital beamforming and analog beamforming is proposed. Summary of the invention

[0009] Various embodiments of the present disclosure are set forth by independent claims. Exemplary embodiments and features described in this specification that do not belong to the scope of the independent claims, if any, are to be construed as useful examples for understanding various exemplary embodiments of the present disclosure.

[0010] Some embodiments relate to an apparatus for a communication system as defined in claim 1. In some embodiments, the first information may, for example, be used to perform digital beamforming.

[0011] In some embodiments, the communication system may be a wireless communication system.

[0012] In some embodiments, the wireless communication system may comply with and / or may be based on some recognized (and / or planned) standards, such as 3G, 4G, 5G, 6G or some other wireless communication standards.

[0013] In some embodiments, the apparatus may be an apparatus for a network device (e.g., a base station, such as a gNB).

[0014] In some embodiments, the device or its function may be provided in the network device, respectively. In some other embodiments, the device or its function may be provided outside the network device.

[0015] In some embodiments, the apparatus may be an apparatus for a terminal device (eg, user equipment (UE)).

[0016] In some embodiments, the device or its function may be provided in the terminal device, respectively. In some other embodiments, the device or its function may be provided outside the terminal device.

[0017] In some embodiments, the apparatus may be configured to perform hybrid beamforming that includes aspects of digital beamforming and analog beamforming.

[0018] In some embodiments, the first analog beam for receiving the first reference signal may be obtained, for example, by means of analog beamforming. Similarly, the second analog beam for receiving the second reference signal may also be obtained, for example, by means of analog beamforming.

[0019] In some embodiments, for example, the first reference signal and the second reference signal may be, for example, a sounding reference signal according to some recognized standard, for example a sounding reference signal (SRS) according to a 5G or 6G standard.

[0020] Note that in some embodiments, the first reference signal may include at least one reference signal. In other words, as used herein, "first reference signal" may, for example, include one or more reference signals, such as one or more first reference signals. Similarly, in some embodiments, the second reference signal may include at least one reference signal. In other words, as used herein, "second reference signal" may, for example, include one or more reference signals, such as one or more second reference signals.

[0021] In some embodiments, the first measurement and the second measurement are consecutive measurements. In other words, in some embodiments, no further measurements associated with the reference signal (eg, SRS) are performed between the first measurement and the second measurement.

[0022] In some embodiments, the duration between the first measurement and the second measurement may be an SRS period, for example according to some recognized standard.

[0023] In some embodiments, the instructions, when executed by at least one processor, cause the apparatus to: perform digital beamforming in a first direction using a digital beamformer, and perform analog beamforming in a second direction, the second direction being different from the first direction.

[0024] In some embodiments, digital beamforming is performed, for example, in the horizontal direction, and analog beamforming is performed, for example, in the vertical direction.

[0025] In some other embodiments, digital beamforming and analog beamforming may also be performed, for example, both in the vertical direction.

[0026] As an example, in some embodiments, four relatively narrow simulated beams may be used in the vertical direction, where, for example, each simulated beam is associated with a different elevation angle.

[0027] When executed by at least one processor, these instructions cause the device to: determine a measurement vector characterizing a first reference signal and a second reference signal based on the first measurement and the second measurement, determine a first covariance matrix based on the measurement vector, determine a second covariance matrix based on the first covariance matrix, and associate the second covariance matrix with at least one of the first simulated beam and the second simulated beam. For example, determine the second covariance matrix for any simulated beam (e.g., including the first simulated beam and the second simulated beam).

[0028] In some embodiments, when the instructions are executed by at least one processor, the apparatus performs at least one of the following: a) according to Z SRS =(w H w) -1 w H y determines the measurement vector, where Z SRS represents the measurement vector, where where y i A first measurement characterizing a first reference signal associated with a first simulated beam, wherein y k a second measurement characterizing a second reference signal associated with a second simulated beam, wherein where w i represents the weight matrix associated with the first simulated beam, where w k represents the weight matrix associated with the second simulated beam, where w H is the conjugate transpose of w, where () -1 Representation matrix inversion, b) according to The first covariance matrix is ​​determined based on the measurement vector, where R zzCharacterize the first covariance matrix, c) according to A second covariance matrix is ​​determined based on the first covariance matrix, where Characterizing a covariance matrix associated with at least one of the first simulated beam and the second simulated beam. For example, a second covariance matrix is ​​determined for any simulated beam (eg, including the first simulated beam and the second simulated beam).

[0029] In some embodiments, the instructions, when executed by at least one processor, cause the device to perform at least one of the following: a) determine a digital beam for exchanging, e.g., sending and / or receiving, signals based on first information; b) exchange (e.g., send and / or receive) signals using the digital beam; and c) update the digital beam.

[0030] In some embodiments, digital beams (and / or corresponding analog beams) may be used to exchange control signals, such as control signals according to some recognized standard.

[0031] As an example, in some embodiments, a digital beam (and / or a corresponding analog beam) may be used to send and / or receive at least one of the following signals: a) a signal associated with a physical downlink shared channel, PDSCH, and / or b) a signal associated with a physical uplink shared channel, PUSCH, for example according to some recognized standards.

[0032] In some embodiments, these instructions, when executed by at least one processor, cause the device to: determine an estimate of a measurement vector based on a first measurement and a second measurement, determine a first covariance matrix for the estimate based on the estimate, determine a second covariance matrix related to the estimate based on the estimated first covariance matrix, and the second covariance matrix is ​​associated with one of the first simulated beam and the second simulated beam.

[0033] In some embodiments, these instructions, when executed by at least one processor, cause the device to perform at least one of the following: a) determine the accuracy of the estimate of the measurement vector, for example based on the normalized mean square error (NMSE); b) determine the accuracy of a second covariance matrix associated with the estimate, for example based on the NMSE.

[0034] Some embodiments relate to an apparatus for a communication system, the apparatus comprising components for determining a first measurement of a first reference signal associated with a first analog beam used to receive a first reference signal, determining a second measurement of a second reference signal associated with a second analog beam used to receive a second reference signal, and determining first information characterizing a digital beamformer based on the first measurement and the second measurement.

[0035] In some embodiments, the means for determining the first and second measurements and for determining the first information may, for example, include at least one processor and at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus to perform the aforementioned aspects.

[0036] In some embodiments, the means for determining the first measurement and the second measurement and the means for determining the first information may, for example, comprise circuitry configured to perform the above-described aspects.

[0037] Some embodiments relate to a network device (e.g., a base station, such as a gNB) for a communication system, comprising at least one apparatus according to an embodiment.

[0038] Some embodiments relate to a terminal device (eg, UE) for a communication system, comprising at least one apparatus according to an embodiment.

[0039] Some embodiments relate to a communication system comprising at least one of the following: a) an apparatus according to an embodiment, and / or b) a network device according to an embodiment, and / or c) a terminal device according to an embodiment.

[0040] Some embodiments relate to a method for a communication system, comprising: determining a first measurement of a first reference signal associated with a first analog beam used to receive a first reference signal, determining a second measurement of a second reference signal associated with a second analog beam used to receive a second reference signal, and determining first information characterizing a digital beamformer based on the first measurement and the second measurement.

[0041] A further embodiment relates to a computer program comprising instructions which, when executed by a computer, cause the computer to perform at least some aspects of the method according to the embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1A schematically shows a simplified block diagram according to some embodiments,

[0043] Figure 1B schematically shows a simplified block diagram according to some embodiments,

[0044] Figure 2 schematically shows a simplified block diagram according to some embodiments,

[0045] Figure 3 schematically illustrates a simplified flow chart according to some embodiments,

[0046] Figure 4 schematically illustrates a simplified flow chart according to some embodiments,

[0047] Figure 5schematically illustrates a simplified signaling diagram according to some embodiments,

[0048] Figure 6 schematically shows a simplified block diagram according to some embodiments,

[0049] Figure 7 schematically illustrates a simplified flow chart according to some embodiments,

[0050] Figure 8 schematically illustrates a simplified flow chart according to some embodiments,

[0051] Fig. 9 schematically illustrates a simplified flow chart according to some embodiments,

[0052] Fig.10 schematically illustrates a simplified flow chart according to some embodiments,

[0053] Fig.11 Schematically illustrated is a simplified block diagram according to some embodiments. Specific embodiments

[0054] For some examples, see Figure 1A , Figure 2 , Figure 3 , relating to a communication system 1000( Figure 2 ) of the device 100( Figure 1A ), the device 100 includes at least one processor 102 ( Figure 1A ), and at least one memory 104 storing instructions 106, which, when executed by at least one processor 102, cause the apparatus 100 to: determine 300 ( Figure 3 ) and the first analog beam 1 used to receive the first reference signal (see Figure 5 ), determining 302 ( Figure 3 ) and the second analog beam 2 ( Figure 5 ), based on the first measurement RS-M-1 and the second measurement RS-M-2, determining 304 ( Figure 3 ) characterizes first information I-1 of the digital beamformer DBF. In some embodiments, the first information I-1 may be used, for example, to perform aspects of digital beamforming, see, for example, optional block 306.

[0055] In some embodiments, Figure 2 In the embodiment, the communication system 1000 may be a wireless communication system.

[0056] In some embodiments, the wireless communication system 1000 may comply with and / or may be based on some recognized (and / or planned) standards, such as 3G, 4G, 5G, 6G or some other wireless communication standards.

[0057] In some embodiments, Figure 2 As shown, the apparatus 100 may be an apparatus for a network device 10, such as a base station, such as a gNB.

[0058] In some embodiments, the apparatus 100 or its functionality may be provided separately within the network device 10. In some other embodiments, the apparatus 100 or its functionality may be provided outside the network device 10. Two exemplary variations are Figure 2 It is represented by a dashed rectangle 100 in FIG.

[0059] In some embodiments, Figure 2 As shown, the apparatus 100 may be an apparatus for a terminal apparatus 20 (eg, user equipment (UE)).

[0060] In some embodiments, the apparatus 100 or its functions may be provided in the terminal device 20, respectively. In some other embodiments, the apparatus 100 or its functions may be provided outside the terminal device 20. However, for the sake of clarity, and without loss of generality, the following example disclosure focuses on example embodiments in which the apparatus 100 or its functions are provided for the network device 10 (such as a gNB) and / or in the network device 10, respectively.

[0061] In some embodiments, see Figure 2 , the apparatus 100 may be configured to perform hybrid beamforming, see Figure 2 Example block HBF, hybrid beamforming HBF includes aspects of digital beamforming (see example block DBF) and analog beamforming (see example block ABF).

[0062] In some embodiments, for example, a first analog beam 1 ( Figure 5 ) can be obtained by means of analog beamforming ABF. Similarly, for example, the second analog beam 2 for receiving the second reference signal RS-2 can also be obtained by means of analog beamforming ABF.

[0063] In some embodiments, Figure 2 In the embodiment, the first reference signal RS-1 and the second reference signal RS-2 may be, for example, sounding reference signals, such as sounding reference signals (SRS) according to some recognized standards (eg, 5G or 6G standards).

[0064] In some embodiments, Figure 3In some embodiments, the first measurement RS-M-1 and the second measurement RS-M-2 are continuous measurements. In other words, in some embodiments, no further measurement associated with the reference signal (eg, SRS) is performed between the first measurement RS-M-1 and the second measurement RS-M-2.

[0065] Figure 5 An exemplary scenario is shown, where element E1 represents a gNB (see also, for example, Figure 2 10), where element E2 represents a UE (see also Figure 2 20). Arrows a1, a2, a3, a4 represent corresponding reference signals, such as SRS, periodically transmitted by UE E2 to gNBE1, for example. The SRS according to arrow a1 is received by gNB E1, for example, using the first analog beam 1, wherein the SRS according to arrow a2 is received by gNB E1, for example, using the second analog beam 2. Optionally, additional SRS a3, a4 can be received by gNB E1 using additional analog beams 3, 4.

[0066] As an example, Figure 5 The SRS transmission a1 can be, for example, Figure 2 The first reference signal RS-1 corresponds to, and Figure 5 The SRS transmission a2 can be, for example, Figure 2 corresponds to the second reference signal RS-2.

[0067] In some embodiments, Figure 5 In the embodiment, the duration TD between the first measurement and the second measurement may be, for example, an SRS period according to some recognized standards.

[0068] In some embodiments, Figure 4 In the embodiment, the instructions, when executed by at least one processor, cause the apparatus 100 to: perform 310 digital beamforming in a first direction DIR-1 using a digital beamformer DBF, and perform 312 analog beamforming ABF in a second direction DIR-2, the second direction DIR-2 being different from the first direction DIR-1.

[0069] In some embodiments, for example, digital beamforming DBF is performed in the horizontal direction. For example, analog beamforming ABF is performed in the vertical direction (eg, associated with altitude).

[0070] In some other embodiments, both digital beamforming and analog beamforming may be performed in the vertical direction.

[0071] As an example, in some embodiments, Figure 5In the embodiment of the present invention, four relatively narrow simulated beams 1, 2, 3, 4 may be used in the vertical direction. For example, each of the simulated beams 1, 2, 3, 4 is associated with another elevation angle.

[0072] Figure 6 1 and 2. The exemplary embodiment shows aspects of signal processing for measurements associated with received SRS in some embodiments, wherein a hybrid beamformer (see Figure 2 For example, element E10 represents the configuration of a column of the HBF architecture when applying an analog beamformer (see Figure 2 ABF), element E11 represents the input before the analog phase shifter of the analog beamformer, element E12 represents the weight of the analog phase shifter of the analog beamformer, and element E13 represents a digital port, such as an input.

[0073] For example, when a reference signal such as SRS is received, they Figure 6 In the exemplary configuration of Figure 6 to the right of Figure 6 The left side is processed, for example, undergoing at least one of the following: a) analog phase shift (if any); b) combination; c) amplification; d) analog-to-digital conversion.

[0074] Fig.11 illustratively illustrates aspects of measured signal processing associated with the received SRS in some embodiments. Element E20 represents, for example, a user layer associated with user data to be transmitted, element E21 represents digital beamforming, and element E22 represents a digital transmit / receive chain ("TRX") stream obtained by digital beamforming E21. Element E23 represents analog beamforming, for example by applying selected phase shifter weights, and element E24 represents an analog stream obtained by analog beamforming E23. Element E25 represents a pre-tilt application, for example characterizing a phase shifter to radiator mapping, and element E26 represents a radiator stream.

[0075] Element E27 represents an SRS signal, element E28 represents a pre-tilt application, e.g. similar to element E25, e.g. characterizing a mapping of phase shifters to radiators (for a receive direction). Element E29 represents an analog stream in the receive direction, element E30 represents analog beamforming, e.g. by applying selected phase shifter weights. Element E31 represents a digital TRX stream, element E32 represents a determination of a corresponding covariance matrix, e.g. according to the principles of an embodiment, element E33 represents a digital weight obtained, e.g. by determining block E32. In some embodiments, Figure 7In the embodiment, the instructions, when executed by at least one processor, cause the apparatus 100 to: determine 320 characterizing the first reference signal RS-1 and the second reference signal RS-2 based on the first measurement RS-M-1 and the second measurement RS-M-2 ( Figure 2 ) of the measurement vector MV, and determining 322( Figure 7 ) a first covariance matrix CV-M-1, determining 324 a second covariance matrix CV-M-2 based on the first covariance matrix CV-M-1, the second covariance matrix CV-M-2 being related to the first simulated beam 1 ( Figure 5 ) is associated with at least one item in the second simulated beam 2. For example, a second covariance matrix CV-M-2 is determined for any simulated beam (eg, including the first simulated beam 1 and the second simulated beam 2). Figure 7 Optional block 326 represents optionally determining first information I-1 characterizing the digital beamformer DBF based on the second covariance matrix CV-M-2.

[0076] In some embodiments, Figure 7 In the embodiment, when the instructions are executed by at least one processor, the apparatus 100 executes: according to Z SRS =(w H w) -1 w H y determines 320 the measurement vector MV, where Z SRS Representation, for example, represents the measurement vector MV, where y i Characterization and first simulation beam 1( Figure 5 ) is associated with the first reference signal RS-1 ( Figure 2 ) of the first measurement RS-M-1( Figure 3 ), y k Characterization and second simulation beam 2 ( Figure 5 ) is associated with a second reference signal RS-2 ( Figure 2 ) of the second measurement RS-M-2( Figure 3 ),in w i Characterizing the weight matrix associated with the first simulated beam 1 (e.g., Figure 6 Box E12), w k represents the weight matrix associated with the second simulated beam, w H is the conjugate transpose of w, () -1 Representation matrix inversion.

[0077] In some embodiments, Figure 7 In the embodiment, when the instructions are executed by at least one processor, the apparatus 100 executes: Determine 322 based on the measurement vector MV ( Figure 7)The first covariance matrix CV-M-1, where R zz Characterize the first covariance matrix CV-M-1.

[0078] In some embodiments, Figure 7 In the embodiment, when the instructions are executed by at least one processor, the apparatus 100 executes: A second covariance matrix CV-M-2 is determined 324 based on the first covariance matrix CV-M-1, wherein Characterizing the Second Covariance Matrix CV-M-2 In some embodiments, the second covariance matrix CV-M-2 may be determined for any simulated beam (eg, including the first simulated beam 1 and the second simulated beam 2).

[0079] In the following, further exemplary aspects and exemplary embodiments are disclosed, which in some embodiments may be combined with each other and / or with at least one of the aforementioned aspects.

[0080] In some embodiments, different simulation beams 1, 2 ( Figure 5 ) observed two consecutive SRS measurement sets (eg, reference signals RS-1, RS-2 ( Figure 2 )) is used to determine the first information I-1 and / or the corresponding digital beamformer as described below.

[0081] In some embodiments, assuming that y i is the SRS measurement vector after the simulated beam i is applied, where y i The size is N T ×1,N T is, for example, the number of digital transmit / receive chains ("TRXs") used to receive SRS.

[0082] In some embodiments, assuming that Z SRS is the SRS measurement vector (e.g., at least similar to Figure 7 The measurement vector MV), where Z SRS The size is N P ×1,N P is, for example, the number of phase shifters used to receive SRS.

[0083] In some embodiments, assuming that w i is the weight matrix corresponding to the simulated beam i, where w i The size is N T ×N T N P .

[0084] In some embodiments, y i With Z SRSThe relationship between i =w i Z SRS .

[0085] In some embodiments, the first aspect ("step 1") may include one or more of the following aspects. i Determine Z SRS In some examples, y i A single measurement may not be sufficient to determine Z SRS , because it forms an underdetermined system to solve Z SRS However, in some embodiments, by performing, for example, simulations corresponding to two different simulated beams i and k (e.g., Figure 5 Two measurements (i≠k) of simulated beam 1 and simulated beam 2 (e.g., two different measurements) can yield a well-determined system, where y i =w i Z SRS and k =w k Z SRS In some embodiments, according to Z SRS =(w H w) -1 w H y, use y i and k Solving for Z SRS . and can be executed. Note that this is according to some embodiments from y i and k Get Z SRS In some embodiments, the principles and subsequent methods according to the exemplary description of the exemplary embodiments are also applicable to any other equation solving methods, for example.

[0086] Note that in some embodiments, such as when w is full rank, the pseudo-inverse (w H w) -1 w H Simplified to w -1 .

[0087] In some embodiments, the second aspect ("step 2") may include one or more of the following aspects. In some embodiments, Z SRS can be used to determine (e.g., calculate) the SRS The corresponding covariance matrix R zz ,because

[0088] In some embodiments, the third aspect ("step 3") may include one or more of the following aspects. In some embodiments, y corresponding to any simulated beam i i The covariance matrix of Can be determined as: (For example, instead of y i )

[0089] In some embodiments, for example, subsequently, Can be used, for example, to determine digital beams (e.g., DIG-B, see Figure 8 ). In some embodiments, the digital beam may be used, for example, for signal exchange, for example, PDSCH transmission and / or PUSCH reception.

[0090] In some embodiments, the digital beam so determined may be used, for example, for PDSCH transmission and / or PUSCH reception, for example between reception of subsequent SRS measurements, and may be updated, for example, when SRS measurements are received in the next period (e.g., SRS period).

[0091] In some embodiments, Z is at least temporarily stored. SRS A digital beamformer may be allowed to determine the (eg, current) best analog beam independent of the UE 20, thereby alleviating the need to store the covariance matrix for each analog beam, for example according to some conventional approaches.

[0092] In some embodiments, principles according to the embodiments may be used for static channels as well as time-varying channels over which reference signals may be received.

[0093] In some embodiments, in the case of a static channel, the channel over which the SRS is exchanged (e.g., sent, e.g., by the UE 20 to the gNB 10) does not change between two SRS receptions. In this case, in some embodiments, the first information I-1 and / or Z may be accurately determined. SRS , we can also accurately determine R zz and

[0094] In some embodiments, Figure 8In the embodiment, the instructions, when executed by at least one processor, cause the apparatus 100 to perform at least one of the following: a) determine 330 a digital beam DIG-B for exchanging 332 (e.g., sending and / or receiving) signals based on the first information I-1, b) exchange 332 (e.g., send and / or receive) signals CS using the digital beam DIG-B, c) update 334 the digital beam DIG-B, e.g., based on further measurements (e.g., SRS measurements), e.g., after a subsequent SRS period, whereby an updated digital beam DIG-B' may be obtained. In some embodiments, the updated digital beam DIG-B' may be used for exchanging signals, e.g., similar to Figure 8 Frame 332.

[0095] In some embodiments, digital beams (and / or corresponding analog beams) may be used to exchange control signals (e.g., control signals according to some recognized standard). Figure 8 The signal CS that may be exchanged by block 332 may be a control signal.

[0096] As an example, in some embodiments, digital beam DIG-B (and / or corresponding analog beams 1, 2, 3 or 4 ( Figure 5 )) sends and / or receives at least one of the following signals: for example, according to some recognized standards, a) a signal associated with a physical downlink shared channel PDSCH, and / or b) a signal associated with a physical uplink shared channel PUSCH.

[0097] In some embodiments, Fig. 9 In the embodiment, the instructions, when executed by at least one processor, cause the device 100 to: determine 340 an estimate EST-MV of the measurement vector MV based on the first measurement RS-M-1 and the second measurement RS-M-2, determine 342 a first covariance matrix CV-M-1-EST-MV for the estimate EST-MV based on the estimate EST-MV, determine 344 a second covariance matrix CV-M-2-EST-MV associated with the estimate based on the first covariance matrix CV-M-1-EST-MV for the estimate, the second covariance matrix CV-M-2-EST-MV being associated with one of the first simulated beam 1 and the second simulated beam 2. In some embodiments, the process can be used, for example, when the reference signals RS-1 and RS-2 are exchanged through a time-varying channel. Optional box 346 indicates that, optionally, the first information I-1 is determined based on the second covariance matrix CV-M-2-EST-MV.

[0098] In some embodiments, for example, in the case of a time-varying channel, for example, from one SRS transmission to a subsequent SRS transmission, the channel over which the SRS is transmitted may change. In some embodiments, this means that in two consecutive or consecutive SRS measurements considered in some embodiments, the underlying ZSRS However, in some embodiments, there may be a certain degree of correlation between the channels of consecutive SRS transmissions, i.e., the underlying Z values ​​from two corresponding consecutive measurements may be SRS There may be a certain degree of correlation between them.

[0099] Thus, in some embodiments, similar methods as exemplarily described above with respect to embodiments associated with static channels may be used.

[0100] In some embodiments, for example, before the simulated beam is applied, it is assumed that Z SRS,t is the estimated SRS measurement at time t, Z SRS,t+p is the estimated SRS measurement at time t+p (e.g., at least similar to that given by Fig. 9 The estimated EST-MV obtained in box 340).

[0101] Note that in some embodiments, t+p and Z SRS,t+p cannot be determined (eg observed) directly, since in some embodiments the correlation signal may be measured / estimated, for example, only after applying the simulated beam weights.

[0102] In some embodiments, p may be an SRS transmission period, for example, see Figure 5 In some embodiments, assuming that y i,t is the SRS measurement at time t after the simulated beam i is applied, and assuming y k,t+p is the SRS measurement at time t+p after (another) simulated beam k is applied.

[0103] In some embodiments, for example, according to y i,t and k,t+p Two consecutive measurements of Z SRS,t+p In some embodiments, assuming It's Z SRS,t+p In some embodiments, determining (e.g., calculating) In some embodiments, for at least one (e.g., any one) simulated light beam i, it is determined (e.g., calculated)

[0104] In some embodiments, it is proposed to determine, for example calculate, the corresponding covariance matrix of one or more (eg, all) simulated beams in the current channel.

[0105] In some embodiments, for example, due to Z SRS,t and Z SRS,t+p In a time-varying channel, it is different. Can contain Z with beam iSRS,t (e.g., of the previous channel) and Z with beam k SRS,t+p Therefore, in some embodiments, the inherent information of the current channel is used. It is possible to efficiently determine (e.g., calculate) y k,t+p and the corresponding covariance matrix (e.g., of the current channel). Moreover, in some embodiments, y may also be determined i,t (e.g., compute) and the corresponding covariance matrix (e.g., of the previous channel). However, in some embodiments, in the current channel time slot t+p, (i≠k) may not be accurate because May contain Z with simulated beam k SRS,t+p , but does not contain information with simulated beam i.

[0106] In view of this, in some embodiments, Fig.10 In the instructions, when executed by at least one processor, the device 100 performs at least one of the following: a) determining 350 the accuracy ACC-EST-MV of the estimate EST-MV of the measurement vector, for example based on the normalized mean square error (NMSE), b) determining 352 the accuracy ACC-2-EST-MV of the second covariance matrix CV-M-2-EST-MV related to the estimate, for example based on the NMSE.

[0107] Therefore, in some embodiments, to measure the estimated to Z SRS,t+p The accuracy of the normalized mean square error (NMSE) can be used, and in some embodiments, to measure arrive The accuracy of The NMSE of (“RNMSE”) is as follows:

[0108] where ||·|| represents the L2 norm of the vector, and ||·|| F Represents the Frobenius norm of a matrix.

[0109] As an example, in some embodiments, NMSE may take y k,t+p The norm of the difference between the estimated measurement and the actual measurement is expressed as y k,t+p The actual norm of is used to normalize it.

[0110] As another example, in some embodiments, similarly, RMNSE may be taken to correspond to y k,t+pThe Frobenius norm of the difference between the estimated covariance matrix and the actual covariance matrix of , and the corresponding y k,t+p The actual covariance matrix of is normalized.

[0111] Figure 1B In some embodiments, an apparatus 100' for a communication system 1000 is provided, the apparatus 100' comprising a component 102', the component 102' being used to: determine 300( Figure 3 ) a first measurement of a first reference signal associated with a first analog beam used to receive a first reference signal, determining 302 a second measurement of a second reference signal associated with a second analog beam used to receive a second reference signal, and determining 304 first information characterizing a digital beamformer based on the first measurement and the second measurement.

[0112] In some embodiments, Figure 1B In the embodiment, the means for determining the first measurement and the second measurement and the device 102' for determining the first information may for example include at least one processor 102 ( Figure 1A ) and at least one memory 104 storing instructions 106, which when executed by at least one processor 102 cause the device to perform the above-mentioned aspects.

[0113] In some embodiments, Figure 1B The means 102 ′ for determining the first measurement and the second measurement and for determining the first information may, for example, comprise a circuit configured to perform one or more of the above aspects.

[0114] Figure 2 In the embodiments, some embodiments relate to a network device 10 (eg, a base station, eg, a gNB) for a communication system 1000, comprising at least one device 100, 100' according to the embodiments.

[0115] Figure 2 In the present invention, some embodiments relate to a terminal device 20 (eg, UE) for a communication system 1000, comprising at least one apparatus 100, 100' according to the embodiments.

[0116] Figure 2 In the present invention, some embodiments relate to a communication system 1000, at least one of the following: a) an apparatus 100, 100' according to an embodiment, and / or b) a network device 10 according to an embodiment, and / or c) a terminal device 20 according to an embodiment.

[0117] Figure 3In some embodiments, a method for a communication system 1000 is provided, comprising: determining 300 a first measurement of a first reference signal associated with a first analog beam used to receive a first reference signal, determining 302 a second measurement of a second reference signal associated with a second analog beam used to receive a second reference signal, and determining 304 first information characterizing a digital beamformer based on the first measurement and the second measurement.

[0118] In some embodiments, the method may include one or more further aspects according to these embodiments.

[0119] Figure 1A In the present invention, further embodiments relate to a computer program comprising instructions 106 which, when executed by a computer, for example comprising a processor 102, cause the computer to perform at least some aspects of the method according to the embodiments.

[0120] In the following, further exemplary aspects and exemplary embodiments are disclosed, which in some embodiments may be combined with each other and / or with at least one of the aforementioned aspects.

[0121] In some embodiments, hybrid beamforming HBF (HBF) using a combination of digital beamforming DBF and analog beamforming ABF Figure 2 ), the cost and / or weight of the apparatus 100 and / or the target device 10, 20 used for the apparatus can be reduced. In addition, in some embodiments, the complexity and / or power consumption can be reduced by hybrid beamforming HBF, for example, by reducing the number of RF signal processing chains.

[0122] As described above, in some embodiments, a hybrid beamforming architecture may be provided that uses digital beamforming in the horizontal direction and analog beamforming in the vertical direction, for example, because the distribution of UEs or users in the horizontal direction is large, while the distribution of users in the vertical direction is relatively low. In some embodiments, the low distribution of users in the vertical direction may mean that a relatively small number of analog beams in the vertical direction is sufficient (for example) to provide adequate coverage in the vertical direction.

[0123] In some embodiments, due to the additional phase shifters that may be included in the analog beamformer ABF, using a hybrid beamforming HBF (eg, instead of digital beamforming) for SRS reception may result in the SRS measurement being “colored” by the lens of the analog beamformer ABF.

[0124] In some embodiments, for example, at elevation angles {-2, -5, -8, -11} degrees, four relatively narrow analog beams 1, 2, 3, 4 ( Figure 5 ), for example, used in a 5G communication system 1000.

[0125] In some examples, for example, using conventional methods (eg, determining the UE's digital beamformer at any time), channel estimates and corresponding covariance matrices for at least all four analog beams must be determined.

[0126] In some examples, for example, for the case of four analog phase shifter settings and two TRXs per column for the HBF architecture, it may be necessary to calculate the channels and corresponding covariance matrices for up to 20 different beams (not shown). Thus, it may be necessary to calculate digital beamformers for all of these analog beams because, in some embodiments, the best analog beam for a UE may change over time based on changing channel conditions. In addition, in HBF, a UE may sometimes be scheduled on its second or even third or later best analog beam, for example to reduce the delay of waiting for the UE's best beam to be scheduled.

[0127] In some conventional approaches, a digital beamformer is determined by making as many estimates / measurements as analog beams and by using the measurements made on the analog beams only for that analog beam.

[0128] In contrast, the principles of an embodiment enable the digital beamformer (or the corresponding first information I-1) to be determined so that, for example, instead of performing as many estimates / measurements as an analog beam and using the measurements performed on the analog beam only for that analog beam, in some embodiments, only two (e.g. (but not necessarily) consecutive) SRS measurements performed on any two different analog beams are used.

[0129] In other words, in some embodiments, these two measurements are sufficient to select a digital beam for any analog beamformer, thereby, for example, saving the number of measurements and avoiding delays and outdated estimates.

[0130] Further, in some embodiments, for example, rather than storing a covariance matrix corresponding to each analog beam, in some embodiments only the covariance matrix of the channel before the phase shifter may be stored, and in some embodiments this matrix may then be used to determine the covariance matrix at the digital port (e.g., digital input). In some embodiments, this applies to static channels as well as time-varying channels.

Claims

1. An apparatus (100) for use in a communication system (1000), the apparatus (100) comprising at least one processor (102) and at least one memory (104) storing instructions (106), the instructions, when executed by the at least one processor (102), causing the apparatus (100) to: determining (300) a first measurement (RS-M-1) of a first reference signal (RS-1) associated with a first simulated beam (1) used to receive the first reference signal (RS-1), determining (302) a second measurement (RS-M-2) of a second reference signal (RS-2) associated with a second simulated beam (2) used to receive the second reference signal (RS-2), determining (304) first information (I-1) characterizing a digital beamformer (DBF) based on the first measurement (RS-M-1) and the second measurement (RS-M-2), wherein the instructions (106), when executed by the at least one processor (102), cause the apparatus (100) to: determining (320) a measurement vector (MV) characterizing the first reference signal (RS-1) and the second reference signal (RS-2) based on the first measurement (RS-M-1) and the second measurement (RS-M-2), determining (322) a first covariance matrix (CV-M-1) based on the measurement vector (MV), determining (324) a second covariance matrix (CV-M-2) based on the first covariance matrix (CV-M-1), the second covariance matrix (CV-M-2) being associated with at least one of the first simulated beam (1) and the second simulated beam (2), The first information (I-1) characterizing the digital beamformer (DBF) is determined (326) based on the second covariance matrix (CV-M-2).

2. The device (100) according to claim 1, wherein the first measurement (RS-M-1) and the second measurement (RS-M-2) are consecutive measurements.

3. The apparatus (100) of claim 1 or 2, wherein the instructions (106), when executed by the at least one processor (102), cause the apparatus (100) to: Digital beamforming is performed (310) in a first direction (DIR-1) and analog beamforming is performed (312) in a second direction (DIR-2) different from the first direction using the digital beamformer (DBF).

4. The apparatus (100) of claim 1, wherein the instructions, when executed by the at least one processor (102), cause the apparatus (100) to perform at least one of the following: a) According to Z SRS =(w H w) -1 w H y determines (320) the measurement vector (MV), where Z SRS represents the measurement vector (MV), where where y i characterizes said first measurement (RS-M-1) of said first reference signal (RS-1) associated with said first simulated beam (1), wherein y k characterizing said second measurement (RS-M-2) of said second reference signal (RS-2) associated with said second simulated beam (2), wherein where w i represents the weight matrix associated with the first simulated beam (1), where w k represents the weight matrix associated with the second simulated beam (2), where w H is the conjugate transpose of w, where () -1 Representation matrix inversion, b) According to The first covariance matrix (CV-M-1) is determined (322) based on the measurement vector (MV), where R zz Characterize the first covariance matrix (CV-M-1), c) According to The second covariance matrix (CV-M-2) is determined (324) based on the first covariance matrix (CV-M-1), wherein Characterizing the covariance matrix (CV-M-2) associated with at least one of the first simulated beam (1) and the second simulated beam (2).

5. The apparatus (100) of claim 1 or 2, wherein the instructions (106), when executed by the at least one processor (102), cause the apparatus (100) to perform at least one of the following: a) determining (330) a digital beam (DIG-B) for exchanging, e.g. sending and / or receiving, signals based on said first information (I-1), b) exchanging, e.g., sending and / or receiving, (332) signals using said digital beam (DIG-B), c) Updating (334) the digital beam (DIG-B).

6. The apparatus (100) of claim 1 or 2, wherein the instructions (106), when executed by the at least one processor (102), cause the apparatus (100) to: determining (340) an estimate of a measurement vector (EST-MV) based on the first measurement (RS-M-1) and the second measurement (RS-M-2), determining (342) a first covariance matrix (CV-M-1-EST-MV) for the estimate (EST-MV) based on the estimate (EST-MV), Based on the first covariance matrix (CV-M-1-EST-MV) for the estimate (EST-MV), A second covariance matrix (CV-M-2-EST-MV) associated with the estimate (EST-MV) is determined (324), the second covariance matrix (CV-M-2-EST-MV) being associated with one of the first simulated beam (1) and the second simulated beam (2).

7. The apparatus (100) of claim 6, wherein the instructions (106), when executed by the at least one processor (102), cause the apparatus (100) to perform at least one of the following: a) determining (350) an accuracy (ACC-EST-MV) of said estimate (EST-MV) of said measurement vector, b) determining (352) an accuracy (ACC-2-EST-MV) of said second covariance matrix (CV-M-2-EST-MV) associated with said estimate (EST-MV).

8. An apparatus (100') for a communication system (1000), the apparatus (100') comprising a component (102'), the component (102') being configured to: determining (300) a first measurement (RS-M-1) of a first reference signal (RS-1) associated with a first simulated beam (1) used to receive the first reference signal (RS-1), determining (302) a second measurement (RS-M-2) of a second reference signal (RS-2) associated with a second simulated beam (2) used to receive the second reference signal (RS-2), determining (304) first information (I-1) characterizing a digital beamformer (DBF) based on the first measurement (RS-M-1) and the second measurement (RS-M-2), determining (320) a measurement vector (MV) characterizing the first reference signal (RS-1) and the second reference signal (RS-2) based on the first measurement (RS-M-1) and the second measurement (RS-M-2), determining (322) a first covariance matrix (CV-M-1) based on the measurement vector (MV), determining (324) a second covariance matrix (CV-M-2) based on the first covariance matrix (CV-M-1), the second covariance matrix (CV-M-2) being associated with at least one of the first simulated beam (1) and the second simulated beam (2), The first information (I-1) characterizing the digital beamformer (DBF) is determined (326) based on the second covariance matrix (CV-M-2).

9. A network device (10) for a communication system (1000), comprising at least one apparatus (100; 100') according to any one of the preceding claims.

10. A terminal device (20) for a communication system (1000), comprising at least one apparatus (100; 100') according to any one of claims 1 to 8.

11. A communication system (1000), comprising at least one of the following: a) A device (100; 100') according to any one of claims 1 to 8, and / or b) The network device (10) according to claim 9, and / or c) The terminal device (20) according to claim 10.

12. A method for a communication system (1000), comprising: determining (300) a first measurement (RS-M-1) of a first reference signal (RS-1) associated with a first simulated beam (1) used to receive the first reference signal (RS-1), determining (302) a second measurement (RS-M-2) of a second reference signal (RS-2) associated with a second simulated beam (2) used to receive the second reference signal (RS-2), determining (304) first information (I-1) characterizing a digital beamformer (DBF) based on the first measurement (RS-M-1) and the second measurement (RS-M-2), Wherein the method further comprises: determining (320) a measurement vector (MV) characterizing the first reference signal (RS-1) and the second reference signal (RS-2) based on the first measurement (RS-M-1) and the second measurement (RS-M-2), determining (322) a first covariance matrix (CV-M-1) based on the measurement vector (MV), determining (324) a second covariance matrix (CV-M-2) based on the first covariance matrix (CV-M-1), the second covariance matrix (CV-M-2) being associated with at least one of the first simulated beam (1) and the second simulated beam (2), The first information (I-1) characterizing the digital beamformer (DBF) is determined (326) based on the second covariance matrix (CV-M-2).

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