Method and apparatus for improving channel estimation

Abstract

The invention relates to a method and an apparatus for improving channel estimation. An electronic device includes: a communication circuit that receives a physical channel from a base station; a memory; and a processor that determines whether the precoding maintenance signal is received from the base station, and transmits a precoding change restriction request to the base station based on a determination that the precoding maintenance signal is not received. The precoding change restriction request corresponds to a request to maintain a precoding matrix applied by the base station at a specific interval.

Description

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2024-0119563, filed on September 3, 2024, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure relates to a method and apparatus in a wireless communication system. More specifically, this disclosure relates to a method and apparatus for improving channel estimation in a wireless communication system. Background Technology

[0004] In new radio (NR) communication environments, base stations use precoding techniques to support multi-layer transmission. Base station precoding can be modified for each time slot and is transparent to the terminal; therefore, the terminal is unaware of information regarding the base station precoding.

[0005] When a terminal uses the demodulation reference signal (DMRS) of adjacent time slots, channel estimation performance can be improved. However, the DMRS of adjacent time slots cannot be used when the precoding differs between them. In other words, adjacent DMRS can only be used if the precoding is the same between adjacent time slots, but the base station does not notify the terminal that the precoding between adjacent time slots has been changed. To address this issue, a method has been proposed for the terminal to detect whether there is a precoding change between adjacent time slots. However, when the base station changes the precoding for each time slot, the DMRS in adjacent time slots may still not be used. Summary of the Invention

[0006] This disclosure provides a method and apparatus for improving channel estimation based on ensuring the same precoding matrix across time slots.

[0007] According to one aspect of this disclosure, an electronic device is provided, comprising: a communication circuit configured to receive a physical channel from a base station; a memory storing at least one instruction; and at least one processor, wherein when executed by the at least one processor, the at least one instruction is configured to control the electronic device to: determine whether a precoding sustain signal has been received from the base station; and send a precoding change restriction request to the base station based on the determination that no precoding sustain signal has been received, wherein the precoding change restriction request corresponds to a request for maintaining a precoding matrix applied by the base station at a first interval.

[0008] According to another aspect of the disclosure, an operating method of an electronic device is provided that includes determining whether a precoding maintenance signal is received from a base station, and transmitting a precoding change restriction request to the base station based on a determination that the precoding maintenance signal is not received, wherein the precoding change restriction request corresponds to a request to maintain a precoding matrix applied by the base station for a first interval.

[0009] According to another aspect of the disclosure, a base station is provided that includes communication circuitry configured to transmit a physical channel to an electronic device, a memory that stores at least one instruction, and at least one processor, wherein, when executed by the at least one processor, the at least one instruction is configured to control the base station to transmit a precoding change restriction to the electronic device, and transmit a downlink signal based on a precoding matrix during a precoding maintenance interval based on the precoding change restriction, wherein the precoding change restriction corresponds to a request to maintain a precoding matrix applied by the base station for a first interval. BRIEF DESCRIPTION OF DRAWINGS

[0010] The embodiments will be understood more fully from the following detailed description, taken in conjunction with the accompanying drawings, in which:

[0011] Figure 1 A wireless communication system according to an embodiment is shown;

[0012] Figure 2 is a block diagram of a base station according to an embodiment;

[0013] Figure 3 is a block diagram of an electronic device according to an embodiment;

[0014] Figure 4 A multiple input multiple output (MIMO) environment according to an embodiment is shown;

[0015] Figure 5 An example of channel estimation according to an embodiment is shown;

[0016] Figure 6 is a flowchart illustrating an operating method of a base station according to an embodiment;

[0017] Figure 7 is a flowchart illustrating an operating method of a base station according to an embodiment;

[0018] Figure 8 is a flowchart illustrating an operating method of a base station according to an embodiment;

[0019] Figure 9 An example of a table for indicating precoding change between adjacent slots according to an embodiment is shown;

[0020] Figure 10is a flowchart illustrating an operation method of an electronic device according to an embodiment;

[0021] Figure 11 is a flowchart illustrating an operation method of an electronic device according to an embodiment; and

[0022] Figure 12 is a block diagram of a wireless communication device according to an embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

[0024] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, same drawing reference numerals are used for same elements across different drawings.

[0025] In order to clearly describe the present disclosure, parts irrelevant to the description are omitted from the accompanying drawings, and throughout the specification, like reference numerals refer to like or similar constituent elements.

[0026] Throughout the present specification and in the claims that follow, when an element is described as "coupled / connected" to another element, the element can be "directly coupled / connected" to the other element, or "indirectly coupled / connected" to the other element through a third element. Also, unless explicitly described to the contrary, the word "comprise" and variations, such as "comprises" or "comprising," will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0027] According to one or more embodiments, various operations and / or functions described below can be implemented in a hardware approach. For example, according to some embodiments, the methods described below can be implemented by an electronic device configured to perform the described operation(s) or function(s). The electronic device can include a block, which can be referred to herein as a manager, unit, module, hardware component, “er” term, etc., can be physically implemented by analog circuitry and / or digital circuitry, such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits, etc., and can optionally be driven by firmware. For example, the circuitry can be embodied in one or more semiconductor chips, or on a substrate support such as a printed circuit board, etc. The circuitry making up a block can be implemented by dedicated hardware, or a processor (e.g., one or more programmed microprocessors and related circuitry), or a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block. Each block of an embodiment can be physically separated into two or more interacting and discrete blocks without departing from the scope of the present disclosure. Likewise, blocks of an embodiment can be physically combined into more complex blocks without departing from the scope of the present disclosure. However, the present disclosure is not limited as such, and thus a block that can be referred to herein as a manager, unit, module, etc. can be a software module implemented by software code, program code, software instructions, etc. The software module can be executed on one or more processors.

[0028] According to one or more embodiments, various methods, operations, and / or functions described below can be implemented or supported by artificial intelligence techniques or one or more computer programs, each of which is configured with computer-readable program code and executed on a computer-readable medium. The term “computer-readable medium” includes any type of medium accessible by a computer, such as read-only memory (ROM), random-access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or other type of memory. A “non-transitory” computer-readable medium excludes wired links, wireless links, optical links, or other communication links that

[0029] Figure 1 A wireless communication system 10 according to an embodiment is shown.

[0030] Reference Figure 1The wireless communication system 10 can include a base station 110 and an electronic device 120. However, the present disclosure is not limited thereto, and thus the wireless communication system 10 can include a plurality of base stations and a plurality of electronic devices according to an embodiment. According to various embodiments, the base station 110 can include a network infrastructure that provides wireless access to the electronic device 120. According to an embodiment, the coverage of the base station 110 can be defined as a certain geographic area based on the distance of signal transmission. The base station 110 can also be referred to as an access point (AP), an eNodeB (eNB), a 5thgeneration node (5G node), a wireless point, or other terms having equivalent technical meanings thereto.

[0031] According to various embodiments, the base station 110 can be connected to one or more transmission / reception points (TRPs). The base station 110 can transmit a downlink signal to or receive an uplink signal from the electronic device 120 via the one or more TRPs.

[0032] According to an embodiment, the base station 110 can transmit a physical channel to the electronic device 120. For example, the physical channel can include, but is not limited to, at least a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), and a physical downlink control channel (PDCCH). The physical channel can include a reference signal (RS). The RS can be a demodulation RS (DMRS). The base station 110 can precode a transmission signal to be transmitted to the electronic device 120 and generate a physical channel. The base station 110 can variably determine a precoding matrix to the electronic device 120. For example, the precoding matrix applied to each slot, respectively, can be different, or the precoding matrix applied to each slot, respectively, can be the same.

[0033] According to an embodiment, base station 110 can notify electronic device 120 that it will not change the precoding matrix. For example, base station 110 can provide electronic device 120 with information about the precoding matrix applied to one or more time slots in the physical channel. For example, this information can indicate whether base station 110 will change the precoding matrix applied to the time slots in the physical channel. For example, this information can indicate whether and / or when base station 110 will change the precoding matrix applied to the time slots in the physical channel. For example, base station 110 can provide electronic device 120 with information indicating the length of the interval in which the precoding matrix will not be changed, or information indicating that the precoding matrix will not be changed until a specific event occurs. Based on this information, an interval in which the precoding matrix will not be changed can be guaranteed for electronic device 120, and electronic device 120 can improve channel estimation performance by interpolating the DMRS channel estimation results of adjacent time slots during this interval. A detailed description thereof is provided below.

[0034] According to various embodiments, electronic device 120 may include a device used by a user and communicating with base station 110 via a wireless channel. In addition to the term "terminal," electronic device 120 may also be referred to as user equipment (UE), mobile station, subscriber station, customer premises equipment (CPE), remote terminal, wireless terminal, user device, or other terms with equivalent technical meanings.

[0035] According to an embodiment, electronic device 120 may request base station 110 not to change the precoding matrix.

[0036] Figure 2 This is a block diagram of base station 200 according to an embodiment.

[0037] refer to Figure 2 Base station 200 may include wireless communication circuit 210, backhaul communication circuit 220, memory 230, and control circuit 240. However, this disclosure is not limited thereto, and thus, according to another embodiment, base station 200 may include one or more additional components, one or more components may be omitted, or one or more components may be combined together. Figure 2 The base station 200 can correspond to Figure 1 Base station 110 in the middle.

[0038] According to an embodiment, the wireless communication circuit 210 can perform the function of transmitting and receiving signals through a wireless channel. According to an embodiment, the wireless communication circuit 210 can perform the conversion function between baseband signals and bit strings according to the physical layer standard of the communication system. In the example case of transmitting data, the wireless communication circuit 210 can generate complex symbols by encoding and modulating the transmitted bit string. In the example case of receiving data, the wireless communication circuit 210 can recover the received bit string by demodulating and decoding the baseband signal. Furthermore, the wireless communication circuit 210 can up-convert the baseband signal to a radio frequency (RF) band signal and then transmit the RF band signal through an antenna, or it can down-convert the RF band signal received through the antenna back to a baseband signal. For example, the wireless communication circuit 210 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc.

[0039] The wireless communication circuit 210 can transmit and receive signals. For example, the wireless communication circuit 210 can transmit synchronization signals (SS), RS, system information, messages, control information, or data. Furthermore, the wireless communication circuit 210 can perform beamforming. The wireless communication circuit 210 can apply beamforming weights to the signal to provide directionality for the signal to be transmitted and received. The wireless communication circuit 210 can modify the formed beam and repeatedly transmit the signal.

[0040] The backhaul communication circuit 220 can provide an interface for communicating with other nodes in the communication network. For example, the backhaul communication circuit 220 can convert a bit string sent from the base station 200 to another node into a physical signal, and can convert a physical signal received from another node into a bit string. The other node may include, but is not limited to, another access node, another base station, a higher node, the core network, etc.

[0041] The memory 230 can store data used for the operation of the base station 200. This data may include, but is not limited to, basic programs, application programs, program code, software instructions, and setting information. The memory 230 may include volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory.

[0042] The control circuit 240 can control the operation of the base station 200. For example, the control circuit 240 transmits and receives signals via the wireless communication circuit 210 or the backhaul communication circuit 220. Furthermore, the control circuit 240 can write data to and read data from the memory 230. For example, the control circuit 240 may include at least one processor.

[0043] According to an embodiment, the control circuit 240 may further include a precoding control circuit 245. The precoding control circuit 245 can determine the parameters to be sent to an electronic device (e.g., Figure 1 The precoding matrix is ​​used for the transmission signals of electronic devices 120 in the system.

[0044] In the context of related technologies, the control circuit according to the comparative example can variably set the precoding matrix based on the channel environment. For example, the precoding control circuit can change the precoding matrix for each time slot. Because the precoding matrix can be changed for each time slot, and the base station does not notify the electronic equipment whether the precoding matrix has been changed, a disadvantage of the electronic equipment according to the comparative example is that it can only improve channel estimation performance by interpolating the channel estimation results of DMRS after identifying whether the precoding matrix is ​​the same between adjacent time slots.

[0045] According to an embodiment, the precoding control circuit 245 can determine whether to maintain precoding. According to an embodiment, maintaining precoding can be referred to as precoding maintenance. For example, precoding maintenance can correspond to not changing the precoding matrix applied to the transmitted signal within a specific interval. Precoding maintenance can also be referred to as precoding change constraint. The precoding control circuit 245 can ensure for the electronic device 120 that the precoding matrix has the same interval between adjacent time slots by signaling a specific event or the length of the precoding maintenance interval.

[0046] For example, the precoding control circuit 245 of base station 200 can indicate to electronic device 120 the length of the interval in which the precoding matrix is ​​not changed (or the precoding change constraint interval) (e.g., a specific number of time slots, subframes, frames, etc.). In this case, electronic device 120 can determine that the precoding matrix will remain the same within the length of the interval received from base station 200.

[0047] According to an embodiment, the precoding control circuit 245 of base station 200 can specifically notify electronic device 120 of the time when the precoding matrix is ​​changed. The precoding control circuit 245 can instruct electronic device 120 to change the precoding matrix based on the occurrence of a specific event. For example, the specific event may include, but is not limited to, the time of receiving a channel state information (CSI) report or the time of receiving a probe RS. Based on the specific event, electronic device 120 can determine that the precoding matrix remains the same until electronic device 120 sends a CSI report or probe RS to base station 200.

[0048] According to an embodiment, the precoding control circuit 245 of base station 200 can indicate to electronic device 120 the result of a comparison with adjacent time slots. The precoding control circuit 245 can indicate to electronic device 120 whether to change the precoding matrix between the previous and current time slots and whether to change the precoding matrix between the current and next time slots. Various signaling methods for notifying base station 200 that the precoding matrix has not been changed are described below.

[0049] Figure 3 This is a block diagram of an electronic device 300 according to an embodiment.

[0050] refer to Figure 3 The electronic device 300 may include a communication circuit 310, a memory 320, and a control circuit 330. However, this disclosure is not limited thereto, and thus, according to another embodiment, the electronic device 300 may include one or more additional components, one or more components may be omitted, or one or more components may be combined together. Figure 3 The electronic device 300 can correspond to Figure 1 120 electronic devices.

[0051] The communication circuit 310 can perform the functions of transmitting and receiving signals via a wireless channel. For example, the communication circuit 310 performs the conversion function between baseband signals and bit strings according to the physical layer standard of the system. For example, when transmitting data, the communication circuit 310 can generate complex symbols by encoding and modulating the transmitted bit string. Furthermore, when receiving data, the communication circuit 310 can recover the received bit string by demodulating and decoding the baseband signal. In addition, the communication circuit 310 can up-convert the baseband signal to an RF band signal and then transmit the RF band signal through an antenna, or it can down-convert the RF band signal received through the antenna back to a baseband signal. For example, the communication circuit 310 may include, but is not limited to, transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, ADCs, etc. The communication circuit 310 can perform beamforming. The communication circuit 310 can apply beamforming weights to the signal to be transmitted and received to provide directionality.

[0052] Communication circuit 310 can transmit and receive signals. Communication circuit 310 can receive downlink signals or transmit uplink signals. Downlink signals may include SS, RS, system information, configuration messages, control information, or downlink data. For example, communication circuit 310 can receive signals from a base station (e.g., Figure 1 The base station 110 receives downlink physical channels including RS. The downlink physical channels may include, but are not limited to, PDSCH, PDCCH and PBCH.

[0053] Memory 320 can store data used for the operation of electronic device 300. This data may include, but is not limited to, basic programs, application programs, program code, software instructions, and setting information. Memory 320 may include volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. Furthermore, memory 320 can provide the stored data based on a request from control circuitry 330. For example, memory 320 can provide the stored data in response to a request from control circuitry 330.

[0054] The control circuit 330 can control the operation of the electronic device 300. For example, the control circuit 330 can control all operations of the electronic device 300. For example, the control circuit 330 can send and receive signals through the communication circuit 310. Furthermore, the control circuit 330 can write data to and read data from the memory 320. For example, the control circuit 330 may include at least one processor or microprocessor, or may be part of a processor. When the control circuit 330 is part of a processor, the communication circuit 310 and part of the control circuit 330 may be referred to as a communication processor (CP).

[0055] According to an embodiment, the control circuit 330 may further include a precoding control circuit 331 and a channel estimation circuit 333. The precoding control circuit 331 may request a base station (e.g., Figure 1 The base station 110 maintains the precoding. Precoding maintenance can correspond to the precoding matrix applied to the transmitted signal not being changed within a specific interval. The precoding control circuit 331 can ensure that the precoding matrix has the same interval between adjacent time slots by signaling to the base station 110 to notify a specific event or the length of the precoding maintenance interval, and the channel estimation circuit 333 can improve the channel estimation performance by interpolating the DMRS channel estimation results of adjacent time slots during the period when the precoding matrix has the same interval between adjacent time slots.

[0056] For example, the precoding control circuit 331 of electronic device 300 can request base station 110 not to change the precoding matrix until a specific event occurs. The specific event may include at least an event in which electronic device 300 sends a sounding reference signal (SRS) to base station 110, or an event in which electronic device 300 sends a CSI report to base station 110. Based on the specific event, electronic device 300 can determine that the precoding matrix remains the same until electronic device 300 sends a CSI report or a sounding RS to base station 110.

[0057] According to an embodiment, the precoding control circuit 331 of the electronic device 300 can request the base station 110 not to change the precoding matrix during a specific interval. For example, this specific time period can be indicated by any number of time slots, subframes, frames, etc., desired by the electronic device 300. Based on this request, the electronic device 300 can anticipate that the precoding matrix is ​​the same for each time slot during the specific time period requested from the base station 110. The channel estimation circuit 333 of the electronic device 300 can improve the channel estimation performance of the RE (resource element) of the current time slot by interpolating the expected channel estimation results of the DMRS included in adjacent time slots.

[0058] Figure 4 A multiple-input multiple-output (MIMO) environment according to an embodiment is shown.

[0059] refer to Figure 4 Base station 410 and user terminal 420 can communicate with each other using MIMO. Figure 4 Base station 410 in the middle can correspond to Figure 1 Base station 110 in the middle, and Figure 4 The user terminal 420 in the middle can correspond to Figure 1 Electronic devices 120.

[0060] According to an embodiment, base station 410 may include a plurality of first antennas Ant1_1 and Ant1_2, and user terminal 420 may include a plurality of second antennas Ant2_1 and Ant2_2. Although Figure 4 The illustration shows that base station 410 and user terminal 420 each include two first antennas Ant1_1 and Ant1_2 and two second antennas Ant2_1 and Ant2_2, but this disclosure is not limited thereto. Therefore, according to the embodiments, the inventive concept of this disclosure can be applied to embodiments where base station 410 and user terminal 420 each include two or more antennas.

[0061] Base station 410 may include a first transceiver 411, a second transceiver 412, a first antenna Ant1_1, and a second antenna Ant1_2. The first transceiver 411 and the second transceiver 412 may each be connected to one antenna. For example, the first transceiver 411 may be connected to the first antenna Ant1_1, and the second transceiver 412 may be connected to the second antenna Ant1_2. In an example where base station 410 operates as a transmitting device, the first transceiver 411 and the second transceiver 412 may each operate as a transmitter; and in an example where base station 410 operates as a receiving device, the first transceiver 411 and the second transceiver 412 may each operate as a receiver.

[0062] The first transceiver 411 can generate a first signal Sig by combining a first component carrier signal C1 and a second component signal C2 in transmit mode, and output the generated first signal Sig to the user terminal 420. According to an embodiment, the first transceiver 411 can extract the first component carrier C1 and the second component carrier C2 from the first signal Sig. That is, the first transceiver 411 can extract not only the first component carrier C1 from the first signal Sig, but also the second component carrier C2. Each of the first transceiver 411 and the second transceiver 412 can transmit not only one component carrier signal, but also multiple component carrier signals by combining multiple component carrier signals, and can extract not only one component carrier signal from the first signal Sig, but also multiple component carrier signals. The user terminal 420 may include a third transceiver 421, a fourth transceiver 422, a third antenna Ant2_1, and a fourth antenna Ant2_2. Because the user terminal 420 may be substantially the same as or similar to the base station 410, its description is omitted.

[0063] Figure 5 An example of channel estimation according to an embodiment is shown.

[0064] refer to Figure 5 The horizontal axis represents time, and the vertical axis represents frequency. The numbers on the horizontal axis are symbol indices, and the numbers on the vertical axis are subcarrier indices. According to an embodiment, with a sub-carrier spacing (SCS) of 15 kHz, each time slot may include 14 symbols. However, this disclosure is not limited to 15 kHz SCS and can be applied to various parameter sets (numerologies), such as 30 kHz SCS and 60 kHz SCS. The first time slot (slot n) and the second time slot (slot n+1) constitute a subframe, and the 12 subcarriers in the frequency domain can constitute a resource block (RB).

[0065] Channel estimation circuit (e.g., Figure 3 The channel estimation circuit 333 in the diagram can perform channel estimation on the DMRS. The DMRS can correspond to symbol indices 2 and 11 for each time slot. However, this disclosure is not limited thereto, and thus, according to embodiments, the location for transmitting the DMRS can vary depending on the antenna port, transmission mode, etc.

[0066] The channel estimation circuit 333 can perform channel estimation on resource elements (REs) in the first time slot (slot n) and on REs in the second time slot (slot n+1). In an example where the precoding matrices for the first time slot (slot n) and the second time slot (slot n+1) are the same, the channel estimation circuit 333 can perform inter-slot interpolation channel estimation on REs with symbol indices 12 and 13 in the first time slot (slot n) and REs with symbol indices 0 and 1 in the second time slot (slot n+1). In an example where channel estimation is performed on REs with symbol indices 12 and 13 in the first time slot (slot n) and REs with symbol indices 0 and 1 in the second time slot (slot n+1), channel estimation can be performed by interpolating the channel estimation results of adjacent DMRSs. The channel estimation circuit 333 can perform channel estimation by interpolating the channel estimation results of the DMRS resource element (RE) corresponding to the symbol index 11 of the first time slot (time slot n) and the DMRS RE corresponding to the symbol index 2 of the second time slot (time slot n+1).

[0067] According to an embodiment, in a base station (e.g., Figure 1 The base station 110 sends a signaling notification to maintain the precoded or electronic equipment (e.g., Figure 1 In the example case where electronic device 120 requests base station 110 to maintain precoding, since the precoding is guaranteed to be the same between adjacent time slots (e.g., the first time slot (time slot n) and the second time slot (time slot n+1)), channel estimation can be performed by interpolating the channel estimation results of DMRS without having to separately determine whether the precoding is the same between adjacent time slots.

[0068] Figure 6 This is a flowchart illustrating the operation method of base station 200 according to an embodiment.

[0069] refer to Figure 6 In operating S610, the base station (e.g., Figure 2 The base station 200 can send information about the precoded maintenance interval. For example, the base station can send information to electronic devices (e.g., Figure 3The electronic device 300 sends a signaling notification to the precoding maintenance interval (or precoding change constraint interval). The precoding maintenance interval may include information about the length of the interval in which the precoding matrix is ​​not changed. For example, the precoding maintenance interval may be a natural number less than or equal to m, where m may be the number of symbols per slot according to the current parameter set.

[0070] According to an embodiment, in the example case where the unit of the precoding maintenance interval is a time slot, the start time of the precoding maintenance interval can be calculated from time slot index 0. For example, the precoding maintenance interval can be p time slots. In this case, the precoding matrix can be maintained without change from time slot index 0 to time slot index p-1.

[0071] According to an embodiment, in the example case where the unit of the precoding maintenance interval is a time slot, the start time of the precoding maintenance interval can be calculated from the end time of the current time slot. For example, the precoding maintenance interval can be p time slots. In this example case, the precoding matrix can be maintained without change when the current time slot ends and p time slots have elapsed since the beginning of the next time slot.

[0072] According to an embodiment, base station 200 can provide information about the precoding maintenance interval to electronic device 300 via radio resource control (RRC) signaling. Base station 200 can send "PrecodingChangeRestrictSlot" as the precoding maintenance interval according to Table 1 below.

[0073] [Table 1]

[0074]

[0075] In the above embodiments, the unit notified by the signaling from the base station 200 is described as a time slot, but is not limited thereto. According to various embodiments, the unit of the interval for requesting precoding maintenance may include, but is not limited to, time slots, subframes, and frames.

[0076] In operation S620, base station 200 may transmit downlink signals based on the precoding matrix during the precoding maintenance interval. For example, base station 200 may transmit downlink signals based on a fixed precoding matrix during the precoding maintenance interval. Base station 200 may not change the precoding matrix for the time period determined by the precoding maintenance interval notified to electronic equipment 300 by signaling. For example, base station 200 may receive CSI reports and / or SRS indicating changes in the channel environment during the precoding maintenance interval from electronic equipment 300. According to an embodiment, base station 200 may change the precoding matrix in response to receiving a CSI report and / or SRS. For example, base station 200 must change the precoding matrix based on receiving a CSI report and / or SRS, but this change may be omitted in an example where the precoding maintenance interval has not yet ended.

[0077] Figure 7 This is a flowchart illustrating the operation method of base station 200 according to an embodiment.

[0078] refer to Figure 7 In operating the S710, the base station (e.g., Figure 2 The base station 200 can send information about precoded sustaining time slot candidates. For example, the base station can send information to electronic devices (e.g., Figure 3 The electronic device 300 sends a signaling notification to precoding maintenance slot candidates. Precoding maintenance slot candidates can include slot numbers whose precoding matrix will not change. For example, base station 200 can send “maxNrofPrecodingChangeRestrictSlot” as a precoding maintenance slot candidate according to Table 2 below.

[0079] [Table 2]

[0080]

[0081] According to an embodiment, base station 200 can provide electronic device 300 with information about precoded sustaining time slot candidates via RRC signaling.

[0082] In operation S720, base station 200 can send information about the selected time slot. For example, the base station can send signaling to notify the selected time slot, which is one of the candidate time slots. For example, base station 200 can select a time slot candidate with a time slot number of any integer from 2 to 80 and send signaling to electronic device 300 to notify the time slot number. The signaling can be sent via a media access control-control element (MAC-CE) or a downlink control indicator (DCI). Electronic device 300 can identify the time slot where the precoding matrix maintains the same time slot length by combining the precoded sustaining time slot candidate received via RRC signaling and the integer notified via signaling via MAC-CE or DCI.

[0083] In the above embodiments, the unit notified by signaling from base station 200 is described as a time slot, but is not limited thereto. According to various embodiments, the unit for precoding maintenance candidates may include, but is not limited to, time slots, subframes, and frames.

[0084] In operation S730, base station 200 can transmit downlink signals based on a fixed precoding matrix during the precoding sustaining interval. The precoding sustaining interval can be determined by a combination of the lengths of time slots selected from time slot candidates sent to electronic device 300 via MAC-CE or DCI. Base station 200 may not change the precoding matrix during the time period determined by the precoding sustaining interval notified to electronic device 300 by signaling. For example, base station 200 may receive CSI reports and / or SRS indicating changes in the channel environment during the precoding sustaining interval from electronic device 300. According to an embodiment, base station 200 may change the precoding matrix in response to receiving a CSI report and / or SRS. For example, base station 200 must change the precoding matrix based on receiving a CSI report and / or SRS, but may omit changing the precoding matrix before the precoding sustaining interval has ended.

[0085] Figure 8 This is a flowchart illustrating the operation method of base station 200 according to an embodiment.

[0086] refer to Figure 8 In operating S810, the base station (e.g., Figure 2 The base station 200 can send information about precoded change events. For example, the base station can send information to electronic devices (e.g., Figure 3The electronic device 300 sends a signaling notification of a precoding change event. The precoding change event can be an event indicating the time point at which the base station 200 begins to change the precoding matrix. For example, in the case of codebook-based precoding, the precoding change event can be a CSI report event. According to an embodiment, in the case of SRS-based precoding, the precoding change event can be an SRS transmission event.

[0087] According to an embodiment, base station 200 can provide information about precoding change events to electronic device 300 via RRC signaling. Base station 200 can send "PrecodingChangeRestrictCSIreport" or "PrecodingChangeRestrictSRStx" according to Table 3 below.

[0088] [Table 3]

[0089]

[0090] In operation S820, base station 200 can transmit downlink signals based on a fixed precoding matrix during the precoding maintenance interval. The precoding maintenance interval can correspond to the interval from the time point of sending RRC signaling for a precoding change event sent to electronic device 300 to the time point of the precoding change event occurring. In the example case where base station 200 sends RRC signaling notification "PrecodingChangeRestrictCSIreport" to electronic device 300 with "True", the precoding maintenance interval can continue until the time point when base station 200 receives the CSI report from electronic device 300. In the example case where base station 200 sends RRC signaling notification "PrecodingChangeRestrictSRStx" to electronic device 300 with "True", the precoding maintenance interval can continue until the time point when base station 200 receives the SRS from electronic device 300.

[0091] In operation S830, base station 200 can determine whether a precoding change event has been received. As described above, base station 200 can determine whether a CSI report or SRS has been received from electronic device 300. In the example case where base station 200 does not receive a CSI report or SRS from electronic device 300, base station 200 can determine that the precoding maintenance interval continues and repeatedly perform operation S820. In the example case where a CSI report or SRS has been received from electronic device 300, operation S840 can be performed.

[0092] In operation S840, base station 200 can transmit downlink signals based on the modified precoding matrix. In operation S830, the precoding maintenance interval can end when base station 200 receives a CSI report or SRS from electronic device 300. Accordingly, base station 200 can select an optimal precoding matrix for the modified channel conditions based on the received CSI report or SRS, and transmit downlink signals based on the optimal precoding matrix.

[0093] Figure 9 An example of a table 900, according to an embodiment, is shown for indicating precoding changes between adjacent time slots.

[0094] refer to Figure 9 Table 900 indicates precoding change information between adjacent time slots. For example, the precoding change information may include 2 bits and can be added to DCI format 1_3 and transmitted from base station 200 to electronic device 300 according to Table 4 below.

[0095] [Table 4]

[0096]

[0097] According to an embodiment, in the example case where the precoding change information is "00", the electronic device 300 can decode the DCI to identify that the precoding matrices of the previous time slot (e.g., the (n-1)th time slot) and the next time slot (e.g., the (n+1)th time slot) are the same as the precoding matrix of the current time slot (e.g., the nth time slot). According to the embodiment, since the precoding matrix of the current time slot is the same as the precoding matrix of the previous time slot, the electronic device 300 can perform channel estimation for the REs with symbol indices 0 and 1 in the current time slot by interpolating the DMRS channel estimation results of the previous time slot. For example, based on the fact that the precoding matrix of the current time slot is the same as the precoding matrix of the previous time slot, the electronic device 300 can perform channel estimation for the REs with symbol indices 0 and 1 in the current time slot by interpolating the DMRS channel estimation results of the previous time slot. According to the embodiment, the precoding matrix of the current time slot is the same as the precoding matrix of the next time slot. Therefore, the electronic device 300 can perform channel estimation for the REs with symbol indices of 0 and 1 in the next time slot by interpolating the DMRS channel estimation result of the current time slot. For example, based on the fact that the precoding matrix of the current time slot is the same as the precoding matrix of the next time slot, the electronic device 300 can perform channel estimation for the REs with symbol indices of 0 and 1 in the next time slot by interpolating the DMRS channel estimation result of the current time slot.

[0098] According to an embodiment, in the example case where the precoding change information is "01", the electronic device 300 can decode the DCI to identify that the precoding matrix of the current time slot (e.g., the nth time slot) is the same as the precoding matrix of the previous time slot (e.g., the (n-1)th time slot) (i.e., there is no change in the precoding matrix), and to identify that the precoding matrix of the current time slot is different from the precoding matrix of the next time slot (e.g., the (n+1)th time slot) (i.e., there is a change in the precoding matrix). According to the embodiment, since the precoding matrix of the current time slot is the same as the precoding matrix of the previous time slot, the electronic device 300 can perform channel estimation for the REs with symbol indices 0 and 1 in the current time slot by interpolating the DMRS channel estimation result of the previous time slot. For example, based on the fact that the precoding matrix of the current time slot is the same as the precoding matrix of the previous time slot, the electronic device 300 can perform channel estimation for the REs with symbol indices 0 and 1 in the current time slot by interpolating the DMRS channel estimation result of the previous time slot. According to the embodiment, the precoding matrix of the current time slot is different from the precoding matrix of the next time slot. Therefore, the electronic device 300 can perform channel estimation on the REs with symbol indices of 0 and 1 in the next time slot without using the DMRS channel estimation result of the current time slot. For example, based on the fact that the precoding matrix of the current time slot is different from the precoding matrix of the next time slot, the electronic device 300 can perform channel estimation on the REs with symbol indices of 0 and 1 in the next time slot without using the DMRS channel estimation result of the current time slot.

[0099] According to an embodiment, in the example case where the precoding change information is "10", the electronic device 300 can decode the DCI to identify that the precoding matrix of the current time slot (e.g., the nth time slot) is different from the precoding matrix of the previous time slot (e.g., the (n-1)th time slot) (i.e., there is a change in the precoding matrix), and identify that the precoding matrix of the current time slot is the same as the precoding matrix of the next time slot (e.g., the (n+1)th time slot) (i.e., there is no change in the precoding matrix). According to the embodiment, since the precoding matrix of the current time slot is different from the precoding matrix of the previous time slot, the electronic device 300 can perform channel estimation for the REs with symbol indices of 0 and 1 in the current time slot without interpolating the DMRS channel estimation results of the previous time slot. For example, based on the difference between the precoding matrix of the current time slot and the precoding matrix of the previous time slot, the electronic device 300 can perform channel estimation for the REs with symbol indices of 0 and 1 in the current time slot without interpolating the DMRS channel estimation results of the previous time slot. According to the embodiment, the precoding matrix of the current time slot is the same as the precoding matrix of the next time slot. Therefore, the electronic device 300 can perform channel estimation for the REs with symbol indices of 0 and 1 in the next time slot by interpolating the DMRS channel estimation result of the current time slot. For example, since the precoding matrix of the current time slot is the same as the precoding matrix of the next time slot, the electronic device 300 can perform channel estimation for the REs with symbol indices of 0 and 1 in the next time slot by interpolating the DMRS channel estimation result of the current time slot.

[0100] According to an embodiment, in the example case where the precoding change information is "11", the electronic device 300 can decode the DCI to identify that the precoding matrix of the current time slot (e.g., the nth time slot) is different from the precoding matrix of the previous time slot (e.g., the (n-1)th time slot) (i.e., there is a change in the precoding matrix), and also identify that the precoding matrix of the current time slot is different from the precoding matrix of the next time slot (e.g., the (n+1)th time slot) (i.e., there is a change in the precoding matrix). According to the embodiment, since the precoding matrix of the current time slot is different from all precoding matrices of adjacent time slots, the electronic device 300 can perform channel estimation on the RE without using the DMRS channel estimation result of the current time slot. For example, based on the fact that the precoding matrix of the current time slot is different from all precoding matrices of adjacent time slots, the electronic device 300 can perform channel estimation on the RE without using the DMRS channel estimation result of the current time slot.

[0101] Figure 10 This is a flowchart illustrating the operation method of an electronic device 300 according to an embodiment.

[0102] refer to Figure 10 In operation S1010, electronic devices (e.g., Figure 3The electronic device 300 can determine whether it has been removed from the base station (e.g., Figure 2 The base station 200 receives information regarding precoding maintenance. For example, the electronic device 300 can determine whether it has received signaling from the base station regarding precoding maintenance. Signaling regarding precoding maintenance may include at least one of the following: a precoding maintenance interval instructing the base station 200 not to change the precoding matrix within a specific interval; a precoding change event instructing the base station 200 not to change the precoding matrix before a specific event occurs; and signaling regarding changes to the precoding matrix between adjacent time slots. In the example case where signaling regarding precoding maintenance is received from the base station 200, based on this signaling, the base station 200 may have already maintained the same precoding matrix without changing it in real time. Therefore, the electronic device 300 can terminate the process.

[0103] In operation S1020, electronic device 300 may send a precoding change event request. For example, electronic device 300 may send a signaling notification of the precoding change event request. The precoding change event request may correspond to a request for base station 200 to restrict changes to the precoding matrix until a precoding change event occurs. For example, the precoding change event request may be a request from electronic device 300 to base station 200 to change the precoding matrix solely based on events such as sending a CSI report or SRS.

[0104] According to an embodiment, electronic device 300 can provide a precoding change event request to base station 200 via UE capability signaling. For example, electronic device 300 can send "supportedPrecodingChangeRestrict" as a precoding change event request according to Table 5 below.

[0105] [Table 5]

[0106]

[0107] Figure 11 This is a flowchart illustrating the operation method of an electronic device 300 according to an embodiment.

[0108] refer to Figure 11 In operation S1110, electronic devices (e.g., Figure 3 The electronic device 300 can determine whether it has been removed from the base station (e.g., Figure 2The base station 200 receives information regarding precoding maintenance. For example, the electronic device 300 can determine whether it has received signaling from the base station regarding precoding maintenance. Signaling regarding precoding maintenance may include at least one of the following: a precoding maintenance interval instructing the base station 200 not to change the precoding matrix within a specific interval; a precoding change event instructing the base station 200 not to change the precoding matrix before a specific event occurs; and signaling regarding changes to the precoding matrix between adjacent time slots. In the example case where signaling regarding precoding maintenance is received from the base station 200, based on this signaling, the base station 200 may have already maintained the same precoding matrix without changing it in real time. Therefore, the electronic device 300 can terminate the process.

[0109] In operation S1120, electronic device 300 may send a precoding maintenance interval request. For example, electronic device 300 may send a signaling notification of the precoding maintenance interval request. The precoding maintenance interval request may correspond to a request for base station 200 to restrict changes to the precoding matrix during the interval period indicated by the precoding maintenance interval request. For example, the precoding maintenance interval request may be a request from electronic device 300 to base station 200 to not change the precoding matrix during an interval period corresponding to any number of time slots.

[0110] According to an embodiment, electronic device 300 can provide a precoding maintenance interval request to base station 200 via UE capability signaling. For example, electronic device 300 can send “supportedPrecodingChangeRestrictSlotDL” as a precoding maintenance interval request according to Table 6 below.

[0111] [Table 6]

[0112]

[0113] Figure 12 This is a block diagram of a wireless communication device 1200 according to an embodiment.

[0114] refer to Figure 12 The wireless communication device 1200 may include an application-specific integrated circuit (ASIC) 1210, an application-specific instruction set processor (ASIP) 1230, a memory 1250, a radio frequency integrated circuit (RFIC) 1260, a main processor 1270, and a main memory 1290. However, this disclosure is not limited thereto, and therefore, according to embodiments, the wireless communication device 1200 may include, in addition to...Figure 12 One or more components other than those shown. According to embodiments, one or more components may be omitted or combined. According to an embodiment, the wireless communication device 1200 may include a modem. The modem may include an ASIC 1210, an ASIP 1230, a memory 1250, an RFIC 1260, and a main processor 1270. Figure 12 The wireless communication device 1200 may include an electronic device 120 according to an embodiment.

[0115] RFIC 1260 can be connected to antenna Ant. RFIC 1260 can be configured to receive signals from or transmit signals to the outside via antenna Ant. According to embodiments, RFIC 1260 can receive and transmit signals using a wireless communication network. ASIP 1230 may include a purpose-specific integrated circuit and may support a dedicated instruction set for a particular application, as well as instructions for executing the instruction set. Memory 1250 can communicate with ASIP 1230 and store multiple instructions executed by ASIP 1230 as a non-transitory storage device. For example, as a non-limiting example, memory 1250 may include any type of memory accessible by ASIP 1230. For example, memory 1250 may include, but is not limited to, random access memory (RAM), read-only memory (ROM), magnetic tape, magnetic disk, optical disk, volatile memory, non-volatile memory, and combinations thereof.

[0116] The main processor 1270 can control the wireless communication device 1200 by executing multiple instructions. For example, the main processor 1270 can be configured to perform one or more operations of the wireless communication device 1200 by executing multiple instructions. For example, the main processor 1270 can control ASIC 1210 and ASIP 1230, and can process data received through the wireless communication network or process user input to the wireless communication device 1200. The main memory 1290 can communicate with the main processor 1270 and store the multiple instructions executed by the main processor 1270 as a non-transitory storage device. For example, as a non-limiting example, the main memory 1290 can include any type of memory accessible by the main processor 1270, such as RAM, ROM, magnetic tape, magnetic disk, optical disk, volatile memory, non-volatile memory, and combinations thereof.

[0117] While the inventive concept has been specifically shown and described with reference to embodiments thereof, it should be understood that various changes in form and detail may be made without departing from the spirit and scope of the appended claims.

Claims

1. An electronic device for improving channel estimation, comprising: a communication circuitry configured to receive a physical channel from a base station; a memory storing at least one instruction; and at least one processor, wherein the at least one instruction, when executed by the at least one processor, is configured to control the electronic device to: determine whether a precoding maintenance signal is received from the base station, and transmit a precoding change restraint request to the base station based on a determination that the precoding maintenance signal is not received, wherein the precoding change restraint request corresponds to a request to maintain a precoding matrix applied by the base station for a first interval. 2.The electronic device of claim 1, wherein the precoding change restraint request includes one of a precoding change event or a length of a precoding change restraint interval. 3.The electronic device of claim 2, wherein the precoding change restraint request is transmitted to the base station through user equipment (UE) capability signaling. 4.The electronic device of claim 2, wherein the precoding change event corresponds to a time point at which a channel state information (CSI) report or a sounding reference signal (SRS) is received by the base station. 5.The electronic device of claim 1, wherein the at least one processor is further configured to perform channel estimation for resource elements of a current time slot by interpolating channel estimation results of demodulation reference signals (DMRSs) of adjacent time slots during the first interval corresponding to the precoding change restraint request. 6.An operating method of an electronic device, the operating method comprising: determining whether a precoding maintenance signal is received from a base station; and transmitting a precoding change restraint request to the base station based on a determination that the precoding maintenance signal is not received, wherein the precoding change restraint request corresponds to a request to maintain a precoding matrix applied by the base station for a first interval. 7.The operating method of claim 6, wherein the precoding change restraint request includes one of a precoding change event or a length of a precoding change restraint interval. 8.The operating method of claim 7, wherein the precoding change restraint request is transmitted to the base station through user equipment (UE) capability signaling. 9.The operating method of claim 7, wherein the precoding change event corresponds to a time point at which a channel state information (CSI) report or a sounding reference signal (SRS) is received by the base station. 10.The operating method of claim 6, further comprising performing channel estimation for resource elements of a current time slot by interpolating channel estimation results of demodulation reference signals (DMRSs) of adjacent time slots during the first interval corresponding to the precoding change restraint request. 11.A base station for improving channel estimation, comprising: a communication circuitry configured to transmit a physical channel to an electronic device; a memory storing at least one instruction; and at least one processor, wherein the at least one instruction, when executed by the at least one processor, is configured to control the base station to: transmit a precoding change restraint to the electronic device, and transmit a downlink signal based on a precoding matrix during a precoding maintenance interval based on the precoding change constraint, wherein the precoding change constraint corresponds to maintaining the precoding matrix applied by the base station for a first interval.

12. The base station of claim 11, wherein the precoding change constraint comprises one of a precoding change event or a length of a precoding maintenance interval.

13. The base station of claim 12, wherein the precoding change event is transmitted to the electronic device through radio resource control (RRC) signaling, medium access control - control element (MAC-CE), or downlink control indicator (DCI).

14. The base station of claim 12, wherein the precoding change event corresponds to a time point at which a channel state information (CSI) report or a sounding reference signal (SRS) is received by the base station.

15. The base station of claim 12, wherein the length of the precoding maintenance interval is signaled as a number of change constraint slots or a slot length candidate.

16. The base station of claim 15, wherein the length of the precoding maintenance interval is signaled as the number of change constraint slots, and wherein the number of change constraint slots is transmitted to the electronic device through RRC signaling.

17. The base station of claim 15, wherein the length of the precoding maintenance interval is signaled as the slot length candidate, and wherein the slot length candidate is transmitted to the electronic device through RRC signaling.

18. The base station of claim 17, wherein the at least one processor is further configured to transmit a slot length of one of a plurality of slot length candidates to the electronic device, and wherein the slot length is signaled through medium access control - control element (MAC-CE) or downlink control indicator (DCI).

19. The base station of claim 11, wherein the at least one processor is further configured to provide adjacent slot change information to the electronic device, the adjacent slot change information comprising whether a precoding matrix is changed between a previous slot and a current slot and whether a precoding matrix is changed between the current slot and a next slot.

20. The base station of claim 19, wherein the adjacent slot change information is transmitted to the electronic device through a downlink control indicator (DCI).

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