User device, network device, and method

Abstract

Exemplary embodiments of the present disclosure relate to a method, an apparatus, and a computer storage medium for communication. A terminal device determines a first set of channel quality indicators (CQIs) conditional on a first precoding matrix indicator (PMI) corresponding to a first time unit. A second timing of the first time unit is after a first timing of a first time interval for reporting channel state information (CSI). Then, the terminal device transmits a CSI report including the first set of CQIs and the first PMI to a network device within the first time interval.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate generally to the field of communication technologies, and more particularly, to methods, apparatuses, and computer-readable media for communication.

Background Art

[0002] With the development of communication technologies, multi-antenna transmission has been introduced. In multi-antenna transmission, by carefully adjusting the phase of each antenna element and, in some cases, also the amplitude, multiple antennas on the transmitting side are used to provide directivity, i.e., concentrate the overall transmission power in a certain direction (beamforming), or more generally, concentrate it at a specific location in space. Such directivity can increase the achievable data rate and communication range because the power reaching the target receiver is higher. To efficiently establish a communication link between a transmitter and a receiver, multiple precoder matrices mapped to different beamforming shapes of the transmitter are predefined between the transmitter and the receiver.

[0003] In the case of downlink multi-antenna transmission, a terminal device may measure a channel state information reference signal (CSI-RS) transmitted from a network device and report to the network device in a CSI report a recommended precoder matrix or an indication of a recommended precoder matrix (e.g., a channel quality indicator (CQI)). Then, when performing data transmission to the terminal device, the network device may use the recommended precoder matrix. However, under non-ideal conditions, the preferred precoder matrix may be time-limited, and when the network device is scheduling downlink data transmission for the terminal device after a certain period, the recommended precoder matrix may no longer be applicable.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Overall, exemplary embodiments of the present disclosure provide a method, an apparatus, and a computer storage medium for communication.

Means for Solving the Problems

[0005] In a first aspect, a communication method is provided. The method includes, at a terminal device, determining a first set of Channel Quality Indicators (CQIs) conditioned on a first Precoding Matrix Indicator (PMI) corresponding to a first time unit, wherein a second timing of the first time unit is after a first timing of a first time interval for reporting Channel State Information (CSI), and transmitting a CSI report including the first set of CQIs and the first PMI to a network device within the first time interval.

[0006] In a second aspect, a communication method is provided. The method includes, at a network device, receiving, from a terminal device, a Channel State Information (CSI) report including a first Channel Quality Indicator (CQI) and a first PMI within a first time interval, wherein the first set of CQIs is conditioned on the first Precoding Matrix Indicator (PMI), the first PMI corresponds to a first time unit, and a second timing of the first time unit is after a first timing of a first time interval for reporting the Channel State Information (CSI).

[0007] In a third aspect, a terminal device is provided. The terminal device includes a processor and a memory. The memory is coupled to the processor and stores instructions. When the instructions are executed by the processor, the terminal device is caused to execute the method according to the first aspect described above.

[0008] In a fourth aspect, a network device is provided. The network device includes a processor and a memory. The memory is coupled to the processor and stores instructions. When the instructions are executed by the processor, the network device is caused to execute the method according to the second aspect described above.

[0009] In a fifth aspect, a computer-readable medium storing instructions for causing at least one processor to execute the method according to the first aspect or the second aspect when executed on the at least one processor is provided.

[0010] It should be understood that the summary of the invention is not intended to identify important or essential features of the embodiments of the present disclosure, nor to limit the scope of the present disclosure. Other features of the present disclosure should be readily understandable from the following description.

Brief Description of Drawings

[0011] The above and other objects, features and advantages of the present disclosure will become more apparent by describing some exemplary embodiments of the present disclosure in more detail with reference to the accompanying drawings.

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[0039] In the figures, the same or similar reference numerals represent the same or similar elements.

Embodiments for Carrying Out the Invention

[0040] Here, the principles of the present disclosure will be explained with reference to some exemplary embodiments. It should be understood that these embodiments are described for illustrative purposes only and are intended to assist those skilled in the art in understanding and implementing the present disclosure, and do not imply any limitation on the scope of the present disclosure. The embodiments described herein can be implemented in various ways different from the methods described below.

[0041] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein shall have the same meaning as commonly understood by those skilled in the art of the present disclosure.

[0042] References to "one embodiment", "an embodiment", "exemplary embodiment", etc. in the present disclosure indicate that the described embodiment can include certain features, structures, or characteristics, but each embodiment does not necessarily include such specific features, structures, or characteristics. Furthermore, such phrases do not necessarily refer to the same embodiment. Additionally, when describing a particular feature, structure, or characteristic in relation to an embodiment, it is considered within the knowledge of those skilled in the art that such feature, structure, or characteristic can affect other embodiments, whether explicitly described or not.

[0043] It should be understood that terms such as "first" and "second" can be used herein to describe various elements, but these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the exemplary embodiment, the first element may be named the second element, and similarly, the second element may be named the first element. As used herein, the term "and / or" includes any and all combinations of one or more of the recited terms.

[0044] The terms used in this specification are for the purpose of describing particular embodiments only and are not intended to limit the exemplary embodiments. As used herein, the singular forms "a", "an", and "the" also include the plural forms unless the context clearly dictates otherwise. As used herein, the terms "comprises", "comprising", "has", "having", "includes", and / or "including" specify the presence of the stated features, elements, and / or components, etc., but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0045] In some instances, values, procedures, or devices are referred to as "best", "lowest", "highest", "minimum", "maximum", etc. Such descriptions are intended to indicate that a selection can be made from among a number of functional alternatives in use, and it should be understood that such a selection need not be better, smaller, higher, or otherwise more preferred than other selections.

[0046] As used herein, the term "communication network" means a network that complies with any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA (registered trademark)), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT), and the like. Further, the communication between the terminal device and the network device in the communication network may be realized according to any suitable generation of communication protocol, including but not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), 5.5G, 5G-Advanced network or sixth generation (6G) communication protocol, and / or any other protocol known currently or developed in the future. Embodiments of the present disclosure are applicable to various communication systems. In view of the rapid development of communication, there will naturally be future types of communication technologies and systems that can embody the present disclosure. This should not be regarded as limiting the scope of the present disclosure to only the aforementioned systems.

[0047] As used herein, the term "terminal device" refers to any device having wireless or wired communication capabilities. Examples of terminal devices include user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, tablets, wearable devices, Internet of Things (IoT) devices, Ultra-reliable and Low Latency Communications (URLLC) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, in-vehicle devices for vehicle-to-everything (V2X) communication where X means pedestrian, vehicle, or infrastructure / network, devices for Integrated Access and Backhaul (IAB), satellite and unmanned aerial vehicle systems (UAS) including high altitude platforms (HAP) in non-terrestrial networks (NTN) such as satellite-mounted vehicles or aircraft-mounted vehicles, extended reality (XR) devices including different types of reality such as augmented reality (AR), mixed reality (MR), virtual reality (VR), unmanned aerial vehicles (UAV) which are aircraft without human pilots and are generally referred to as drones, devices on high speed trains (HST), or image acquisition devices such as digital cameras, sensors, game devices, music storage and playback devices, or Internet devices enabling wireless or wired Internet access and browsing, etc., but are not limited thereto.The "terminal device" can further have a multicast / broadcast function and support public safety, mission-critical, V2X applications, transparent IPv4 / IPv6 multicast delivery, IPTV, smart TV, wireless services, wireless software delivery, group communication, and IoT applications. Also, one or more subscriber identity modules (SIMs), known as multi-SIM, may be incorporated. The term "terminal device" may be used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device.

[0048] As used herein, the term "network device" means a device that can provide or host a cell or coverage with which a terminal device can communicate. Examples of network devices include, but are not limited to, satellites, unmanned aerial systems (UAS) platforms, Node B (NodeB or NB), evolved Node B (eNodeB or eNB), next-generation Node B (gNB), transmission reception point (TRP), remote radio unit (RRU), radio head (RH), remote radio head (RRH), IAB node, femto node, low-power nodes such as pico nodes, and reconfigurable intelligent surface (RIS).

[0049] In one embodiment, the terminal device may be connected to a first network device and a second network device. One of the first network device and the second network device may be a master node and the other may be a secondary node. The first network device and the second network device may use different radio access technologies (RATs). In one embodiment, the first network device may be a first RAT device, and the second network device may be a second RAT device. In one embodiment, the first RAT device is an eNB and the second RAT device is a gNB. Information regarding different RATs may be transmitted from at least one of the first network device and the second network device to the terminal device. In one embodiment, the first information may be transmitted from the first network device to the terminal device, and the second information may be transmitted from the second network device directly or via the first network device to the terminal device. In one embodiment, information regarding the settings of the terminal device set by the second network device may be transmitted from the second network device via the first network device. Information regarding the re - settings of the terminal device set by the second network device may be transmitted from the second network device directly or via the first network device to the terminal device.

[0050] The communications described in this specification may conform to any suitable standard, including but not limited to New Radio access (NR), Long-Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), cdma2000, and Global System for Mobile Communications (GSM). Further, the communications may be performed according to any generation of communication protocol known currently or developed in the future. Examples of communication protocols include, but are not limited to, the first generation (1G), second generation (2G), 2.5G, 2.85G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), and sixth generation (6G) communication protocols. The technologies described in this specification can be used in the above-mentioned wireless networks and wireless technologies, as well as other wireless networks and wireless technologies. Embodiments of the present disclosure may be performed according to any generation of communication protocol known currently or developed in the future. Examples of communication protocols include, but are not limited to, the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols, 5.5G, 5G-Advanced network, or sixth generation (6G) network.

[0051] The terminal device or network device may have the ability of artificial intelligence (AI) or machine learning. Generally, a trained model is included from a large number of data collected for a specific function and can be used to predict some information.

[0052] The terminal device or network device may operate, for example, in several frequency ranges such as FR1 (410 MHz to 7125 MHz), FR2 (24.25 GHz to 71 GHz), frequency bands greater than 100 GHz, and terahertz (THz). Furthermore, it can operate on licensed / unlicensed / shared spectrum. The terminal device may have two or more connections with the network device under a multi-radio dual connectivity (MR-DC) application scenario. The terminal device or network device can operate in full-duplex, flexible-duplex, and cross-split duplex modes.

[0053] Embodiments of the present disclosure may be implemented, for example, in test equipment such as a signal generator, a signal analyzer, a spectrum analyzer, a network analyzer, a test terminal device, a test network device, or a channel emulator.

[0054] Embodiments of the present disclosure may be executed according to any generation of communication protocol known currently or developed in the future. Examples of communication protocols include, but are not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G) communication protocol, 5.5G, 5G-Advanced network, or the sixth generation (6G) network.

[0055] As used herein, the term "circuit" may mean a hardware circuit and / or a combination of a hardware circuit and software. For example, a circuit may be a combination of analog and / or digital hardware circuits and software / firmware. As yet another example, a circuit may be any part of a hardware processor with software, including a digital signal processor, software, and one or more memories, that cooperate to perform various functions in a device such as a terminal device or a network device. In yet another example, a circuit may be a hardware circuit and / or a processor such as a microprocessor or a part thereof that requires software / firmware for operation, but the software may not be present if it is not required for operation. As used herein, the term "circuit" also includes the implementation of only a hardware circuit or one or more processors, or a part of a hardware circuit or one or more processors and their (or their) associated software and / or firmware.

[0056] As used herein, the singular forms "a", "an", and "the" also include the plural forms unless the context clearly dictates otherwise. The terms "comprising" and variations thereof should be understood as open-ended terms meaning "including, but not limited to". The term "based on" should be understood as "based at least in part on". The terms "one embodiment" and "embodiment" should be understood as "at least one embodiment". The term "another embodiment" should be understood as "at least one other embodiment". Terms such as "first", "second", etc. may refer to different or the same object. There may be other explicit and implicit definitions below.

[0057] In some examples, a value, procedure, or device is referred to as "best," "lowest," "highest," "minimum," "maximum," etc. Such descriptions are intended to indicate that a selection can be made from among a number of available functional alternatives, and it should be understood that such a selection need not be better, smaller, higher, or otherwise preferable to other selections.

[0058] As described above, the preferred precoder matrix for a terminal device may be time-limited. For example, in some cases, the terminal device may be an electronic device moving at medium or high speed, and since the channel characteristics between the network device and the terminal device may change relatively quickly, when the network device schedules data transmission to the terminal device, the precoder matrix recommended by the terminal device (or the precoder matrix corresponding to the codebook indication reported by the terminal device, such as PMI) may be inapplicable.

[0059] In one solution, for CSI reporting and measurements for type II codebook correction for high-speed / medium-speed, a predetermined length (e.g., N4) of a Doppler-domain (DD) or time-domain (TD) basis vector is used to improve CSI reporting. However, details for improving the CQI conditioned on the CSI report or the precoder matrix indicator (PMI) included in the CSI report are not considered. Further, the association between the CQI reported within the CSI report and the index of the time unit / time interval is also an important aspect.

[0060] Exemplary embodiments of the present disclosure propose a mechanism for CSI reporting and measurement. In this mechanism, a terminal device determines a first set of CQIs conditional on a first PMI, where the first PMI corresponds to a first time unit. A second timing of the first time unit is after a first timing of a first time interval for reporting CSI. Then, the terminal device transmits a CSI report including the first set of CQIs and the first PMI to a network device.

[0061] In this way, the network device can know the CQIs, codebooks, or precoder matrices measured and recommended by the terminal device for time units after or subsequent to the time interval for reporting CSI. And the network device may schedule data transmission for the terminal device based on this CQI, codebook, or precoder matrix. Thus, when the network device schedules data transmission for the terminal device, it can counter the fluctuations in channel characteristics caused by the movement of the terminal device with high / medium speed.

[0062] FIG. 1 shows an exemplary communication system 100 in which some embodiments of the present disclosure can be implemented. The communication system 100, which is part of a communication network, includes a terminal device 110 and a network device 120. The terminal device 110 may be moving at high / medium speed while measuring CSI-RS transmitted from the network device 120 and transmitting a corresponding CSI report. As shown in FIG. 1, the terminal device 110 may move from a first position to a second position when performing CSI-RS measurement and transmitting a CSI report. For clarity of explanation, the timing sequence regarding the measurement of CSI RS, the transmission of CSI report, and the CQI time window is illustrated in FIG. 2. The CQI time window includes at least a part of the time unit associated with the PMI determined by the terminal device for CSI reporting, and the CQIs reported in the CSI report are conditional on these PMIs.

[0063] In system 100, the link from network device 110 to terminal device 110 is referred to as the downlink (DL), and the link from terminal device 110 to network device 110 is referred to as the uplink (UL). In the downlink, network device 120 is a transmitting (TX) device (or transmitter), and terminal device 110 is a receiving (RX) device (or receiver). In the uplink, terminal device 110 is a transmitting TX device (or transmitter), and network device 120 is an RX device (or receiver). It should be understood that network device 120 may provide one or more serving cells. In some embodiments, network device 120 can provide multiple cells.

[0064] Communication in communication system 100 may conform to any suitable standard including, but not limited to, Long-Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), and Global System for Mobile Communications (GSM). Further, the communication may be carried out according to any generation of communication protocol known currently or developed in the future. Examples of communication protocols include, but are not limited to, the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), 5.5G, 5G-Advanced network, or sixth generation (6G) communication protocol.

[0065] It should be understood that the number of devices as shown in FIG. 1 and their connection relationships and types are used for illustrative purposes only and do not imply any limitation. Communication system 100 may include any suitable number of devices suitable for implementing the embodiments of the present disclosure.

[0066] FIG. 2 shows a timing diagram 200 according to some embodiments of the present disclosure. For illustrative purposes, the timing diagram 200 will be described with reference to FIG. 1.

[0067] In timing diagram 200, time interval 210 is used to transmit a CSI report. The terminal device 110 may transmit the CSI report within time interval 210. Time interval 210 may include one or more slots. As an example in FIG. 2, time interval 210 is a slot with index n. In different cases, time interval 210 is determined respectively.

[0068] In periodic or semi-persistent CSI reporting, time interval 210 is periodic in the time domain, and the terminal device 110 may transmit a CSI report to the network device 120 in time interval 210 having a predefined period. In this case, CSI reference resource slot 230 (which may also be referred to as n ref 230) may be determined based on the predefined time interval 210. Generally, the time length 220 between n ref 230 and time interval 210 is predefined, or n ref 230 may be determined by seeking a slot having an index smaller by a predefined value than the index of time interval 210. In one example, n ref 230 is calculated by the following formula (1).

Number

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Number

[0069] The determined n ref 230 represents the timing boundary of the measurement for the CSI - RS transmitted from the network device 120. The terminal device 110 should complete the measurement for the CSI - RS before or at n ref 230 to ensure the processing time for determining the CSI report by the terminal device 110. In some embodiments, the terminal device 110 measures the CSI - RS in a plurality of consecutive slots before n ref 230 to determine at least two PMIs. Also, the plurality of PMIs, each corresponding to a slot, can be measured by the DD / TD basis vectors. The length of these plurality of consecutive slots is also referred to as the CSI - RS measurement window "W meas ". As shown in FIG. 2, the block 240 represents the CSI - RS measurement window associated with n ref 230 for the time interval 210. The position of the CSI - RS measurement window is [k, W means - 1], where k is the slot index of the start slot of the CSI - RS measurement window.

[0070] In addition to periodic or semi-persistent CSI reporting, or as an alternative thereto, CSI reporting may be triggered by downlink control information (DCI) including a CSI request from the network device 120. In this case, the time interval 210 may be determined based on the slot in which the DCI including the CSI request is received. When the terminal device 110 transmits a physical uplink shared channel (PUSCH), the slot delay or slot offset between the slot for receiving the DCI and the time interval 210 is based on the time domain resource allocation for the PUSCH and a predefined slot offset for the CSI reporting. Also, the slot delay or slot offset between the slot for receiving the DCI and the time interval 210 may be based only on the predefined slot offset for the CSI reporting. In this case, similar to the above-described, n ref 230 may be determined based on the time interval 210.

[0071] The CSI report includes a CSI-RS resource indicator (CRI), a rank indicator (RI), a PMI, a CQI, and a layer indicator (LI). The RI is calculated conditional on the CRI. The PMI is calculated conditional on the RI and the CRI. The CQI is calculated conditional on the PMI, the RI, and the CRI. The LI is calculated conditional on the CQI, the PMI, the RI, and the CRI. As described above, in order to cope with high-speed / medium-speed movement of the terminal device 110, the CSI report includes a CQI conditional on the PMI corresponding to a time unit after the time interval 210. The time unit may include one or more slots, and the time unit, unlike the time interval, may have the same time length as the time interval.

[0072] As shown in FIG. 2, the CSI report may include a CQI that is conditional on a PMI corresponding to a time unit 260 with an index “n+M”, where M is a non-negative integer. The PMI corresponding to the time unit 260 is a precoder matrix W(4) or a codebook W(4) for the time unit 260, measured based on the CSI-RS received in the CSI measurement window 240 and the DD / TD basis vectors. In some embodiments, the CSI report includes a plurality of CQIs that are conditional on PMIs corresponding to time units within block 250. The CQI that is conditional on the PMI corresponding to the first time unit among the time units within block 250 is shown as CQI0 in FIG. 2. In some embodiments, the CSI report includes a plurality of CQIs that are conditional on PMIs corresponding to some of the time units within block 260. The PMI corresponding to the some of the time units may be selected based on a predefined criterion that will be described in detail below. In this case, the time units associated with the CSI report span the time interval 210 for transmitting the CSI report. Thus, the CQI that is conditional on the PMI corresponding to the time unit 260 within block 250 is shown as CQI4 in FIG. 2.

[0073] In some other embodiments, the CSI report includes only CQIs that are conditional on PMIs corresponding to time units after the time unit 260 or subsequent time units. In this case, the CQI that is conditional on the PMI corresponding to the time unit 260 is CQI0 (shown as CQI0’ in FIG. 2) within the CSI report.

[0074] Without limitation, for a better understanding of the solutions proposed by the present disclosure, an exemplary timing diagram according to an embodiment of the present disclosure is shown in FIG. 2. Embodiments of detailed processing operations will be further described with reference to FIGS. 3 to 8C. FIG. 3 shows a signaling process 300 according to some embodiments of the present disclosure. For the sake of explanation, the process 300 will be described with reference to FIG. 1.

[0075] In signaling process 300, at 310, the network device 120 transmits bursts of a plurality of CSI-RSs to the terminal device 110 to determine the channel state between the network device 120 and the terminal device 110. In some embodiments, the bursts of the plurality of CSI-RSs include a plurality of CSI-RS resources, and at least one setting / parameter for these CSI-RS resources may be the same. The at least one setting / parameter may include at least one of resourceMapping (frequency domain resources, period, number of symbols, subcarrier occupancy, number of ports, CDM type, density), power, and the TCI state for the plurality of CSI-RS resources. Additionally or alternatively, the bursts of the plurality of CSI-RSs include a first plurality of CSI-RS resources (for example, the number thereof may be 1) and a second plurality of CSI-RSs for tracking.

[0076] Additionally or alternatively, operation 310 may be expressed as follows.

Table 1

[0077] At 320, the terminal device 110 calculates a PMI corresponding to a plurality of time units based on the received bursts of the plurality of CSI-RSs and a DD / TD base vector having a predetermined length (for example, N4). The determined PMI includes at least one or more PMIs corresponding to time units after the first time interval for reporting CSI or subsequent time units.

[0078] Additionally or alternatively, operation 320 may be expressed as follows.

Table 2

[0079] At 330, the terminal device 110 determines a first set of CQIs on the condition of a first PMI corresponding to a first time unit. The second timing of the first time unit is after the first timing of the first time interval for reporting CSI. In the present disclosure, at least the terminal device 110 is configured to have a DD / DD-based report for PMI reporting, or TD / DD compression is applied to the codebook.

[0080] In some embodiments, the first time unit may be the first time unit after the third timing or among subsequent time units, and the third timing may be the first timing. In this case, the first time unit may include a slot of the first time interval and a slot after the first time interval. Therefore, the first PMI corresponding to the first time unit may be a PMI measured for a slot within the first time interval or a slot after the first time interval.

[0081] Additionally or alternatively, the third timing may be the start or end of a time interval corresponding to an index determined based on the first index + M of the first time interval, where M is a non-negative integer. In this case, when M is a positive integer, the first time unit may include a slot after the first time interval. For example, when M = 2, the third timing may be the start or end of a time interval having an index equal to the first index + 2 of the first time interval. Therefore, in one example, the first PMI corresponding to the first time unit may be a PMI measured for a slot after the first time interval, and the difference between the index of the slot and the index of the first time interval is M. Additionally, when M = 0, the third timing may be the first timing.

[0082] In some embodiments, the lengths of the M time intervals are greater than or equal to the time interval for the network device 120 to decode the CSI report. For example, the lengths of the M time intervals are equal to the time interval for the network device 120 to decode the CSI report and prepare for scheduling. In this way, when the network device 120 schedules data transmission to the terminal device 110, the CQI conditional on the PMI corresponding to a future time unit (the time unit for data transmission) may be retrieved from the CSI report. For this reason, the network device 120 may determine a preferable precoder matrix or codebook applicable during the executed data transmission.

[0083] For clarity of explanation, reference is made to FIGS. 4A and 4B to further explain the association between the first set of CQIs and the first PMI. FIG. 4A shows an example 400A of a set of reported channel quality indicators (CQIs) according to some embodiments of the present disclosure.

[0084] In FIG. 4A, as an example, the first set of CQIs is calculated conditional on the PMI corresponding to the first time unit within the time window 410 starting at time unit n+M. Further, the first set of CQIs may include at least one of the first wideband CQI and the first plurality of sub-band CQIs.

[0085] To calculate the first set of CQIs, the terminal device 110 may calculate a plurality of PMIs, each of the plurality of PMIs corresponding to the time units of the time window 410 respectively. For example, for each time unit within the time window 410, the terminal device 110 may calculate the corresponding PMI.

[0086] In some embodiments, the terminal device 110 further calculates an average PMI for a plurality of PMIs corresponding to time units within the time window 410. Then, this average PMI is determined as the first PMI. The terminal device 110 calculates a first set of CQIs on the condition of this average PMI. For example, at least one of the first wideband CQI and the first plurality of sub-band CQIs is determined based on this average PMI.

[0087] In some embodiments, the terminal device 110 obtains a filtered PMI for the time window 410 by repeatedly filtering the PMI in the order of time units of the time window 410. The filtered PMI is determined as the first PMI. The terminal device 110 calculates a first set of CQIs on the condition of this filtered PMI. For example, at least one of the first wideband CQI and the first plurality of sub-band CQIs is determined based on this filtered PMI.

[0088] In this case, the first set of CQIs is determined based on the PMI indicating the calculated codebook or precoder matrix (e.g., W(4), …, W(n4), and W(N4)) included in the block 420. The block 420 corresponds to the time window 410.

[0089] In some other embodiments, the first PMI may be averaged or filtered for the PMI corresponding to another time window that crosses the time unit n, for example, the time window 250 as shown in FIG. 2. Additionally or alternatively, the first PMI may be one PMI corresponding to the time units within the time window 410.

[0090] Figure 4B shows an example 400B of a reported set of Channel Quality Indicators (CQIs) according to some embodiments of the present disclosure. In Figure 4B, as an example, the first PMI may be the calculated PMI corresponding to the time unit n+M. In this case, the first set of CQIs is directly calculated on the condition of the PMI corresponding to the time unit n+M. In this case, the first set of CQIs is determined based on the PMI indicating the calculated codebook or precoder matrix (W(4)). As shown in Figure 4B, the first set of PMIs may include a broadband CQI4 and a plurality of first sub-band CQIs4.

[0091] Additionally or alternatively, the first PMI may also be one of the PMI corresponding to the time unit n or the PMI corresponding to the time units within the time window 410. For example, the first PMI may be the PMI indicating the codebook W(4) or the precoder matrix W(4), as shown in block 430.

[0092] Referring to Figure 3, the terminal device 110 may determine a plurality of sets of CQIs associated with a first plurality of time units, and the first set of CQIs is one of the plurality of sets of CQIs. One set of CQIs among the plurality of sets of CQIs is associated with a time unit among the first plurality of time units and includes at least one of a broadband CQI and a plurality of sub-band CQIs. At least one of the broadband CQI and the plurality of sub-band CQIs is determined based on the PMI corresponding to the associated time unit.

[0093] As an example, there may be two or more sets of CQIs for the broadband corresponding to a set of PMIs and / or for a plurality of sub-bands (including the first set of CQIs), and each set of CQIs (for example,

Number

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Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

[0094] In some embodiments, the first time unit among the first plurality of time units may be a time unit after or subsequent to the first time interval for reporting CSI. For example, the time unit, or the first slot of the time interval, or the index

Number

Number

[0095] Referring to the example of FIG. 4A or FIG. 4B, the first time unit among the first plurality of time units may be time unit n+M. In this case, the plurality of sets of CQIs may be associated with time unit n+M and a plurality of time units after time unit n+M. Further, each set of CQIs is associated with a corresponding time unit. For example, the plurality of sets of CQIs are associated with time units within time window 410, and the number of the plurality of sets of CQIs is equal to the number of time units within time window 410. And each set of CQIs is associated with a corresponding time unit within time window 410. Specifically, the set of CQIs with index i is calculated conditional on the PMI indicating codebook W(i) or precoder matrix W(i). Alternatively, the number of sets of CQIs corresponding to a part of time window 410 is determined.

[0096] In some embodiments, the first time unit among the first plurality of time units may be the first time unit within a time window that straddles the time interval for reporting the CSI. For example, referring to the example of FIG. 2, the first plurality of time units may be time units within time window 250. In this case, the plurality of sets of CQIs may be associated with time units within time window 250, and the number of the plurality of sets of CQIs is equal to the number of time units within time window 250. And each set of CQIs is associated with a corresponding time unit within time window 250. Specifically, the set of CQIs with index i is calculated conditional on the PMI indicating codebook W(i) or precoder matrix W(i). Alternatively, the number of sets of CQIs corresponding to a part of time window 250 is determined.

[0097] Continuing to refer to FIG. 3, at 340, the terminal device 110 transmits a CSI report including the first set of CQIs and the first PMI. In some embodiments, as described above, the CSI report includes a plurality of sets of CQIs associated with the first plurality of time units and the corresponding PMI. In the present disclosure, for simplicity of description, the number of sets within the first plurality of time units is N c and may be.

[0098] In some embodiments, N c is equal to the number of time units within the corresponding time window (e.g., time window 250 of FIG. 2 or time window 410 of FIGS. 4A and 4B). Specifically, each time unit within the corresponding time window has an associated set of CQIs within the CSI report.

[0099] Alternatively, N c is less than the number of time units within the corresponding time window. In this case, only the number of sets of CQIs associated with a portion of the corresponding time window is reported, rather than all sets of CQIs associated with the first plurality of time units reported within the CSI report. There may be a criterion for selecting a reported set of CQIs.

[0100] For example, if the difference between any other set of CQIs (after the first set of CQIs) and the first set of CQIs exceeds a first threshold, the other set of CQIs may be reported within the CSI report. For example, referring to the example of FIG. 2, if the difference between CQI4 (or the set of CQIs 4) conditioned on the PMI indicating W(4) and CQI0 (or the set of CQIs 0) conditioned on the PMI indicating W(0) exceeds the first threshold, CQI4 (or the set of CQIs 4) is reported within the CSI report. Otherwise, the terminal device 110 does not transmit CQI4 (or the set of CQIs 4) within the CSI report.

[0101] Additionally or alternatively, if the difference between a set of CQIs i-1 and a set of CQIs i exceeds a second threshold, the set of CQIs i may be reported within the CSI report. For example, referring to the example of FIG. 2, if the difference between CQI1 (or the set of CQIs 1) conditioned on the PMI indicating W(1) and CQI0 (or the set of CQIs 0) conditioned on the PMI indicating W(0) exceeds the second threshold, CQI2 (or the set of CQIs 2) is reported within the CSI report. Otherwise, the terminal device 110 does not transmit CQI2 (or the set of CQIs 2) within the CSI report.

[0102] Additionally, in some embodiments, if the difference between a set of CQIs or between CQI indexes is very large (e.g., greater than a threshold. For example, the threshold may be at least one of {4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}), the terminal device 110 may consider that the current conditions are not available for determining the channel state and may discard it without transmitting a CSI report. For example, if the difference between any other set of CQIs and the CQIs of the first set exceeds a third threshold, or if the difference between one set of CQIs i-1 and one set of CQIs i and the difference exceeds a fourth threshold, the CSI report is discarded.

[0103] For the payloads of multiple sets of CQIs in the CSI report, for clarity of explanation, reference is made to FIGS. 5A and 5B for description. FIG. 5A shows an example 500A of multiple sets of reported CQIs according to some embodiments of the present disclosure.

[0104] Without limitation, a set of CQIs0 including wideband CQI w _0 and / or multiple sub-band CQIs sb _0, a set of CQIs4 including wideband CQI w_4 and / or multiple sub-band CQIs sb _4, and a set of CQIs w_i including wideband CQI sb _ i are used as examples of sets of CQIs for explaining the payload. For simplicity, in this example, the set of CQIs0 may be the first set of CQIs, the set of CQIs4 may be referred to as the second set of CQIs, and the set of CQIs i may be referred to as the third set of CQIs. i may be referred to as the third set of CQIs.

[0105] In some embodiments, only the first set of CQIs is transmitted within the first part of the CSI report, e.g., CSI part 1, and the second set of CQIs and the third set of CQIs are transmitted within the second part of the CSI report, e.g., CSI part 2. The first set of CQIs may be a set of CQIs associated with the start or end of a time interval corresponding to an index determined based on the index of the first time interval + M, where M is a non - negative integer. Additionally or alternatively, the first set of CQIs may be a set of CQIs associated with the start time unit of a time window across the first time period.

[0106] FIG. 5B is a diagram showing an example 500B of a plurality of sets of reported CQIs according to some embodiments of the present disclosure. As an example shown in FIG. 5B, the wide - band CQI w _0 and / or the first plurality of sub - band CQIs s _0 are transmitted within the first part of the CSI report. Then, the wide - band CQI w _ i and / or the plurality of sub - band CQIs s _ i are transmitted within the second part of the CSI report. For example, the wide - band CQI w _4 and / or the plurality of sub - band CQIs s _4 are transmitted within CQI part 2. In another example, the wide - band CQI w _ i and / or the plurality of sub - band CQIs s _ i are transmitted within CQI part 2. In some embodiments, the CQI w _ i and / or the plurality of sub - band CQIs sb _ i may be shown in differential form with respect to the CQI w _0 and / or the plurality of sub - band CQIs sb _0.

[0107] Referring back to FIG. 5A, the payload of the first wide - band CQI w_0 is the first number of bits, e.g., for example

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Number

[0108] Specifically, the mapping between the sub - band differential CQI value and the offset value is shown in Table 1.

Table 3

[0109] For the CQIs of groups other than the first group of CQIs (for example, the CQIs of the second group and the third group), the corresponding wideband CQI i (for example, CQI w_4 and CQI w_i) may be indicated by the bits of the third number, for example, B3 bits, where B3 = 1, 2, 3, or 4. The bits of the third number are the index i CQI among a set of CQIs with an index i, the wideband CQI (for example, CQI w_4 and CQI w_i ), and the difference value between the wideband CQI (for example, CQI w_0 ) in the first set of CQIs. Next, the first wideband CQI w_0 functions as the standard CQI for other wideband CQIs. For example, in the case of the wideband CQI w_4 , the bits of the third number indicating the difference value between the wideband CQI w_4 and the first wideband CQI w_0 are the payload of the wideband CQI w_4 .

[0110] For each sub-band CQI (for example, CQI sb_i among a plurality of sub-band CQIs sb _4 and CQI sb _ i ), the payload of the sub-band CQI may be the bits of the third number (B3) indicating the difference value between the corresponding sub-band CQI and the wideband CQI w_0 . In this case, the sub-band offset level (for CQI sb_i ) = the sub-band CQI index (for CQI sb_i ) - the wideband CQI index (for CQI w_0 ).

[0111] Alternatively, for each sub-band CQI (for example, CQI sb _4 and CQI sb _ i ) among a plurality of sub-band CQIs, the payload of the sub-band CQI may be the bits of the second number (B2) indicating the difference value between the corresponding sub-band CQI and the corresponding wideband CQI. In one example, for each sub-band CQI of a plurality of CQIs sb_4 , the payload of the sub-band CQI is the difference value between the sub-band CQI and the wideband CQI w_4It may also be the bits of the second number (B2) indicating the difference value from []. In another example, for multiple CQIs sb_i For each sub - band CQI of [], the payload of the sub - band CQI may be the bits of the second number (B2) indicating the difference value between the sub - band CQI and the wide - band CQI w_i It may also be the bits of the second number (B2) indicating the difference value from []. For example, (for CQI sb_i ) sub - band offset level=(CQI sb_i ) sub - band CQI index-(CQI sb_i ) wide - band CQI index.

[0112] In some embodiments, the difference value table may be different from Table 1. For example, only when the CQI difference is large enough, it is necessary to report the set of CQIs i . In some other embodiments, when the first set of CQIs is determined based on searching for the strongest set of CQIs or the weakest set of CQIs, the bits of the third number indicate only non - negative values or non - positive values. The strongest set of CQIs may include the set of CQIs with the strongest absolute value, and the weakest set of CQIs may include the set of CQIs with the smallest absolute value. Specifically, the mapping between the wide - band CQI difference CQI value or the sub - band difference CQI value and the offset value is shown in Table 2 and Table 3.

Table 4

Table 5

[0113] In other embodiments, for each wide - band CQI other than the first wide - band CQI0 (e.g., CQI w_4 and CQI w_i ), the wide - band CQI may be shown in a differential form with respect to the previous wide - band CQI (rather than the first wide - band CQI w_0 ). For example, for wide - band CQI w_4 , the payload is the difference between CQI w_4 and the CQI w_3 associated with the previous time unit.It may include bits of a third number (B3) indicating a difference value from []. Wideband CQI w_i For, the payload may be CQI w_i and the CQI associated with the previous time unit w_(i-1) It may include bits of a third number (B3) indicating a difference value from []. In one example, (for CQI w_i ) wideband offset level = (for CQI w_i ) wideband CQI index - (for CQI w_(i-1) ) wideband CQI index. Each differential wideband CQI w_i (

Number

Number

[0114] And, in this case, for each sub - band CQI among a plurality of sub - band CQIs (e.g., CQI sb _4 and CQI sb _ i ), the payload of the sub - band CQI may be bits of a second number (B2) or a third number (B3) indicating a difference value between the corresponding sub - band CQI and another CQI functioning as a standard CQI. The standard CQI may include one of the first wideband CQI w_0 , the corresponding wideband CQI (e.g., CQI sb _4 and CQI sb _ i ), and the sub - band CQI for the same frequency sub - band corresponding to the previous time unit.

[0115] Wideband CQI w_0 or the corresponding wideband CQI functioning as a standard CQI (e.g., CQI w_4 and CQI w_iRegarding [0], as described above, the payload of the sub - band CQI indicating the difference value was explained. Regarding the sub - band CQI that functions as the standard CQI, in one example, the payload of the sub - band CQI sb _4 may include the bits of the second or third number indicating the difference value between CQI sb _4 and CQI sb _3. CQI sb _3 is the CQI for the same frequency sub - band and corresponds to the previous time unit (i.e., before the time unit associated with CQI sb_4 and consecutive with the time unit associated with CQI sb_4 ). Similarly, the payload of the sub - band CQI sb _ i may include the bits of the second or third number indicating the difference value between CQI sb _ i and CQI sb _ (i-1) . In one example, the sub - band offset level (for CQI sb _ i ) = the sub - band CQI index (for CQI sb _ i ) - the sub - band CQI index (for CQI sb _ i-1 ).

[0116] In some other embodiments, for each of the wide - band CQIs other than the first wide - band CQI0 (e.g., CQI w_4 and CQI w_i ), the payload of the wide - band CQI may include the bits of the first number (B1) or the third number (B3) indicating the absolute value for the wide - band CQI. In this case, the payload of each sub - band within a plurality of sub - band CQIs sb _ i (

Number

Number

[0117] Additionally or alternatively, among the plurality of sets of CQIs, there may be one set of the largest / strongest CQIs. The time unit index or slot corresponding to the index of the strongest set of CQIs and / or the strongest set of CQIs (

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Number

[0118] As described above, the reported set of CQIs may be selected based on a predefined criterion, for example, that the difference between sets of CQIs exceeds a first threshold or a second threshold. Next, the time unit, slot, or time interval associated with the reported set of CQIs should also be reported. In some embodiments, there may be a first indication field indicating the associated time unit, slot, or time interval. The terminal device 110 may transmit the first indication field within a second part of the CSI report, for example, within CSI part 2. For clarity of explanation, refer to FIGS. 6A and 6B and explain the payload of the first indication field.

[0119] FIG. 6A shows a reported corresponding time unit index 600A according to some embodiments of the present disclosure. As shown in FIG. 6A, as an example, a plurality of sets of CQIs associated with at least a part of N5 time units are reported within the CSI report as shown in block 610 of FIG. 6. N5 may be a positive integer and may be less than or equal to the length N4 of the above-described TD / DD basis vector. In some embodiments, N5 = N4. In some other embodiments, N5 = ceil(N4 / A), where A is a positive integer, for example, A ∈ {2, 3, 4, 5, 6, 7, 8, 10, 12, 16}.

[0120] In this case, the payload of the first indication field may be calculated as ceil[log2(C(N5, Nc))], where "ceil" is the ceiling function, C(X,X) is the combination operation, and Nc is the number of sets of CQIs reported as described above. Thus, all possible combinations of selecting Nc time units from N5 time units are mapped to a bit sequence having a length of ceil[log2(C(N5, Nc))]. Each bit sequence uniquely identifies one set of time units associated with the plurality of sets of CQIs.

[0121] In some embodiments, C(a,b) may be a function of nchoosek(a,b). In some embodiments, nchoosek may be a function of selecting k values from n values. In some embodiments, nchoosek(a, b) = a! / (b! * (a - b)!). In some embodiments, "!" may be a factorial. In some embodiments, a! = 1 * 2 * … * (a - 1) * a.

[0122] Additionally or alternatively, there may be a predefined time unit between the network device 120 and the terminal device 110. For example, a time unit associated with the first set of CQIs as described above, for example, T as shown in FIG. 6A CQI_0 is. The network device may know this time unit in advance. In this case, the payload of the first indication field may be calculated as ceil [log2(C(N5 - 1, Nc - 1))]. Additionally or alternatively, the predefined time unit may be any time unit, for example, the start time unit of a time window across the first time interval, and the time unit has an index equal to n + M.

[0123] FIG. 6B shows a reported corresponding time unit index 600B according to some embodiments of the present disclosure.

[0124] The payload of the first indication field may also depend on a certain timing and at least one of N4 (length of the TD / DD base) or the time window associated with the CSI report, and the timing may be a slot for the CSI report (for example, slot n shown in FIG. 6B) or slot n + M. Without limitation, taking the timing of slot n + M as an example. In this case, the bit size of the first indication field may be ceil[log2(C(N5 - X, Nc))], where X is the number of time units earlier than the timing.

[0125] Additionally or alternatively, T in FIG. 6B CQI_0As shown by, there may be a predefined time unit associated with the set of CQIs. In one example, the time unit index corresponding to the first set of CQIs ( [Number] ) may be fixed to a predefined / pre-determined / a certain time unit index or slot, or may be fixed to the first time unit or the first slot before or after that timing. Similarly, the bit size of the first indication field may be ceil[log2(C(N5-X-1, Nc-1))], where X is the number of time units earlier than that timing. In some embodiments, the predetermined time unit may include at least one of the start time unit among the first plurality of time units, the start time unit among the second plurality of time units, and the time unit corresponding to the strongest set of CQIs. In some embodiments, the first indication field is transmitted within the second part of the CSI report, for example, CSI part 2.

[0126] In addition to the payloads of the plurality of sets of CQIs and the payload of the first indication field, resource scheduling regarding Doppler characteristics may be further considered. For clarity of explanation, refer to FIG. 7 and explain the resource scheduling regarding Doppler characteristics.

[0127] FIG. 7 is a timing diagram 700 according to some exemplary embodiments of the present disclosure. The demodulation reference signal (DMRS) of the physical downlink shared channel (PDSCH) is QCL with a QCL source reference signal (for example, CSI-RS or TRS). In the case of TD / DD-based reporting, the channel characteristics are reflected based on TD / DD, and the Doppler characteristics corresponding to the time interval for PDSCH scheduling may be different from the Doppler characteristics corresponding to the time interval for the QCL source RS.

[0128] Next, in the case of TD / DD-based reporting, the UE may assume that the DMRS ports of the PDSCH are quasi-collocated with the DL RS of the TCI state, excluding the quasi-collocation parameters {Doppler shift, Doppler spread}. As shown in FIG. 7, block 710 represents the CSI measurement window. Additionally, the TD / DD-based reported within the CSI and / or QCL source RS may be applied to the quasi-collocation parameters {Doppler shift, Doppler spread}.

[0129] Furthermore, the QCL source RS within the TCI state for PDSCH scheduling may not be the same as or QCL with the RS for CSI acquisition, or if the TCI state for PDSCH is changed within the time interval WCSI, the codebook / CSI report may not be suitable for scheduling. This problem can be solved by the following embodiments of the present disclosure.

[0130] FIGS. 8A and 8B show timing diagrams 800A and 800B according to some exemplary embodiments of the present disclosure. As shown in FIG. 8A, block 810 represents the CSI measurement window, and timing 820 represents the integrated TCI state update. Additionally, as shown in FIG. 8B, the CSI measurement window is not QCL with the QCL source RS within the TCI state and the time unit 830 for PDSCH scheduling.

[0131] The terminal device 110 may expect that the QCL source RS for {Doppler shift} and / or {Doppler spread} within at least the TCI state for PDSCH scheduling is the same as or QCL with the RS for CSI acquisition (codebook with TD / DD base) with respect to the qcl type set to "typeA". Additionally or alternatively, the TD / DD-based reported within the CSI and / or the corresponding (e.g., QCL or related to the QCL source RS within the TCI state for PDSCH) RS for CSI acquisition may be applied to the quasi-collocation parameters {Doppler shift, Doppler spread}.

[0132] FIG. 8C shows a timing diagram 800C according to some exemplary embodiments of the present disclosure. In the case of an integrated TCI framework, if the CSI-RS for CSI acquisition for TD / DD-based codebook reporting and / or the CSI-RS for tracking (e.g., TRS) is not QCL with the RS within the indicated TCI state, the terminal device 110 may discard the CSI report. Alternatively, the UE anticipates that the CSI-RS for CSI acquisition and / or the CSI-RS for tracking is QCL with the RS within the indicated TCI state. As shown in FIG. 8C, the timing 810 indicates that the integrated TCI state has changed or that the RS is not QCL with the CSI-RS for CSI acquisition. At the time unit 850, the CSI report is discarded.

[0133] FIG. 9 is a flowchart of an exemplary method 900 implemented in a terminal device according to some embodiments of the present disclosure. The method 900 can be implemented in the terminal device 110 shown in FIG. 1. For the sake of explanation, the method 900 will be described with reference to FIG. 1. It should be understood that the method 900 may include additional operations not shown and / or may omit some of the operations shown, and the scope of the present disclosure is not limited in this regard.

[0134] At 910, the terminal device 110 determines a first set of CQIs conditional on a first PMI corresponding to a first time unit. The second timing of the first time unit is after the first timing of the first time interval for reporting CSI. At 920, the terminal device 110 transmits a CSI report including the first set of CQIs and the first PMI to the network device 120 within the first time interval.

[0135] In some embodiments, the first time unit is the first time unit among the time units after or subsequent to a third timing, and the third timing includes at least one of the first timing and the start or end of a time interval corresponding to an index determined based on the first index + M of a first time interval, where M is a non-negative integer.

[0136] In some embodiments, the length of M time intervals is greater than or equal to the time interval for the network device to decode the CSI report. In some embodiments, the first set of CQIs includes at least one of a first wideband CQI and a first plurality of subband CQIs. In some embodiments, at least one of the first wideband CQI and the first plurality of subband CQIs is determined based on at least two PMIs including the first PMI. In some embodiments, at least one of the first wideband CQI and the first plurality of subband CQIs is determined based on the first PMI.

[0137] In some embodiments, the CSI report includes a plurality of sets of CQIs associated with a first plurality of time units. The plurality of sets of CQIs includes the first set of CQIs. One set of CQIs among the plurality of sets of CQIs is associated with a time unit among the first plurality of time units and includes at least one of a wideband CQI and a plurality of subband CQIs. At least one of the wideband CQI and the plurality of subband CQIs is determined based on the PMI corresponding to the associated time unit.

[0138] In some embodiments, the CSI report further includes at least one of a second set of CQIs associated with a second time unit and a third set of CQIs associated with a third time unit, where the second time unit is different from the first time unit and the third time unit is different from the second time unit.

[0139] In some embodiments, the second set of CQIs includes at least one of a second wideband CQI and a second plurality of sub-band CQIs, and the at least one of the second wideband CQI and the second plurality of sub-band CQIs is determined based on a second PMI corresponding to a second time unit. The third set of CQIs includes at least one of a third wideband CQI and a third plurality of sub-band CQIs, and the at least one of the third wideband CQI and the third plurality of sub-band CQIs is determined based on a third PMI corresponding to the third time unit.

[0140] In some embodiments, transmitting the CSI report includes transmitting the first set of CQIs within a first portion of the CSI report and transmitting at least one of the second set of CQIs and the third set of CQIs within a second portion of the CSI report.

[0141] In some embodiments, transmitting the CSI report includes at least one of transmitting the second set of CQIs in response to a difference between the second set of CQIs and the first set of CQIs exceeding a first threshold and transmitting the third set of CQIs in response to a difference between the third set of CQIs and the second set of CQIs exceeding a second threshold.

[0142] In some embodiments, for a set of CQIs having index i among the plurality of sets of CQIs CQI the payload of the wideband CQI of the set of CQIs having index i CQI includes at least one of: a first number of bits indicating a value for the wideband CQI of the set of CQIs having index i, a third number of bits indicating a difference value between the wideband CQI of the set of CQIs having index i and the wideband CQI of the first set of CQIs, or a third number of bits indicating a difference value between the wideband CQI of the set of CQIs having index i and the wideband CQI of the set of CQIs having index i CQI -1, CQI and index i CQI is included in at least one of the third number of bits indicating the difference value between the wideband CQI of the set of CQIs having index i and the wideband CQI of the set of CQIs having index i CQIFor one sub - band CQI among a plurality of sub - band CQIs of a set of CQIs having, the payload for the sub - band CQIs is the index i CQI For the one sub - band CQI among the plurality of sub - band CQIs of the set of CQIs having and the index i CQI The second number of bits indicating the difference value between the wide - band CQI of the set of CQIs having and the one sub - band CQI among the plurality of sub - band CQIs of the set of CQIs having, and the index i CQI The third number of bits indicating the difference value between the wide - band CQI of the first set of CQIs and the one sub - band CQI among the plurality of sub - band CQIs of the set of CQIs having, and the index i CQI For the one sub - band CQI among the plurality of sub - band CQIs of the set of CQIs having and the index i CQI The second number of bits or the third number of bits indicating the difference value between the one sub - band CQI among the plurality of sub - band CQIs of the set of CQIs having - 1 and the one sub - band CQI among the plurality of sub - band CQIs of the set of CQIs having, and the one sub - band CQI among the second plurality of sub - band CQIs and the index i CQI The third number of bits indicating the difference value between the wide - band CQI having - 1 and, and at least one of them, where i CQI is a positive integer, and i CQI is greater than 1.

[0143] In some embodiments, the payload for the second wide - band CQI includes the first number of bits indicating the absolute value of the second wide - band CQI, and the payload for the second sub - band CQI among the second plurality of sub - band CQIs includes the second number of bits indicating the difference value between the second sub - band CQI and the second wide - band CQI.

[0144] In some embodiments, the payload of the second wideband CQI includes a third number of bits indicating a difference value between the second wideband CQI and the first wideband CQI, and the payload of the second sub-band CQI among the plurality of second sub-band CQIs includes the third number of bits indicating a difference value between the second sub-band CQI and the first wideband CQI, the second number of bits indicating a difference value between the second sub-band CQI and the second wideband CQI, and at least one of the third number of bits indicating a difference value between the second sub-band CQI and one of the first plurality of sub-band CQIs.

[0145] In some embodiments, the payload of the third wideband CQI includes any one of a third number of bits indicating a difference value between the third wideband CQI and the second wideband CQI, or a third number of bits indicating a difference value between the third wideband CQI and the first wideband CQI, and the payload of the third sub-band CQI among the plurality of third sub-band CQIs includes any one of the second number of bits indicating a difference value between the third sub-band CQI and the third wideband CQI, the third number of bits indicating a difference value between the third sub-band CQI and the second sub-band CQI, or the third number of bits indicating a difference value between the third sub-band CQI and the first sub-band CQI among the first plurality of sub-band CQIs.

[0146] In some embodiments, the payload of the third wideband CQI includes a first number of bits indicating an absolute value of the third wideband CQI, and the payload for the third sub-band CQI among the plurality of third sub-band CQIs includes a second or third number of bits indicating a difference value between the third sub-band CQI and the third wideband CQI.

[0147] In some embodiments, the first time unit is a second plurality of time units including a start time unit among a first plurality of time units and a second number of time units determined from the first plurality of time units, where each time unit is a start time unit among the second plurality of time units after or after that first timing, and a time unit corresponding to the strongest one set of CQI among the plurality of sets of CQI, where the strongest one set of CQI includes a wideband CQI or a subband CQI having a maximum value among the plurality of sets of CQI, and the CSI report includes the time unit including an index value of the time unit corresponding to the strongest one set of CQI, and is one of them.

[0148] In some embodiments, transmitting the CSI report includes transmitting an indication field within a second part of the CSI report, and the indication field indicates the first plurality of time units. In some embodiments, the payload of the indication field is determined based on a fourth number of time units among the first plurality of time units and a number of CQI sets among the plurality of CQI. In some embodiments, the payload of the indication field is determined based on a fifth number of time units among the second plurality of time units and a number of CQI sets among the plurality of sets of CQI.

[0149] In some embodiments, the first set of CQI includes a set of CQI associated with a predetermined time unit among the first plurality of time units, and the predetermined time unit includes at least one of a start time unit among the first plurality of time units and a start time unit among the second plurality of time units, and the payload of the indication field is determined based on one of a result of subtracting 1 from the fourth number and a result of subtracting 1 from the number of CQI sets, and a result of subtracting 1 from the fifth number of time units within the second plurality of time units and a result of subtracting 1 from the number of CQI sets.

[0150] FIG. 10 is a flowchart of an exemplary method 1000 implemented in a terminal device according to some embodiments of the present disclosure. The method 1000 can be implemented in the network device 120 shown in FIG. 1. For the sake of explanation, the method 1000 will be described with reference to FIG. 1. The method 1000 may include additional operations not shown and / or may omit some of the operations shown, and it should be understood that the scope of the present disclosure is not limited in this regard.

[0151] At 1010, the network device 120 receives from the terminal device 110 a CSI report including a first set of CQIs and a first PMI within a first time interval, where the first set of CQIs is conditioned on the first PMI. The first PMI corresponds to a first time unit. A second timing of the first time unit is after a first timing of the first time interval for reporting CSI.

[0152] In some embodiments, the first time unit is the first time unit after a third timing or among subsequent time units, where the third timing includes at least one of a first timing and a start or end of a time interval corresponding to an index determined based on the first index + M of the first time interval, and M is a non-negative integer.

[0153] In some embodiments, the length of the M time intervals is greater than or equal to the time interval for the network device 120 to decode the CSI report.

[0154] In some embodiments, the first set of CQIs includes at least one of a first wideband CQI and a first plurality of subband CQIs. In some embodiments, at least one of the first wideband CQI and the first plurality of subband CQIs is determined based on at least two PMIs including the first PMI. In some embodiments, at least one of the first wideband CQI and the first plurality of subband CQIs is determined based on the first PMI.

[0155] In some embodiments, the CSI report includes a plurality of sets of CQIs associated with a first plurality of time units. The plurality of sets of CQIs includes the first set of CQIs. One set of CQIs among the plurality of sets of CQIs is associated with a time unit among the first plurality of time units and includes at least one of a broadband CQI and a plurality of sub-band CQIs. At least one of the broadband CQI and the plurality of sub-band CQIs is determined based on a PMI corresponding to the associated time unit.

[0156] In some embodiments, the CSI report further includes at least one of a second set of CQIs associated with a second time unit and a third set of CQIs associated with a third time unit, where the second time unit is different from the first time unit and the third time unit is different from the second time unit.

[0157] In some embodiments, the second set of CQIs includes at least one of a second broadband CQI and a second plurality of sub-band CQIs, and the at least one of the second broadband CQI and the second plurality of sub-band CQIs is determined based on a second PMI corresponding to the second time unit. The third set of CQIs includes at least one of a third broadband CQI and a third plurality of sub-band CQIs, and the at least one of the third broadband CQI and the third plurality of sub-band CQIs is determined based on a third PMI corresponding to the third time unit. In some embodiments, receiving the CSI report includes, in a first portion of the CSI report, receiving the first set of CQIs and, in a second portion of the CSI report, receiving at least one of the second set of CQIs and the third set of CQIs.

[0158] In some embodiments, the index i among the plurality of sets of CQIs CQI The payload of the broadband CQI among one set of CQIs having CQIThe first number of bits indicating the value for the wideband CQI among a set of CQIs having [CQI], index i CQI The third number of bits indicating the difference value between the wideband CQI among a set of CQIs having [CQI] and the wideband CQI among the first set of CQIs, or index i CQI The wideband CQI among a set of CQIs having [CQI] and index i CQI At least one of the third number of bits indicating the difference value between the wideband CQI among a set of CQIs having [CQI] and -1, index i CQI The payload for one subband CQI among the plurality of subband CQIs among a set of CQIs having [CQI] is index i CQI The one subband CQI among the plurality of subband CQIs among a set of CQIs having [CQI] and index i CQI The second number of bits indicating the difference value between the wideband CQI among a set of CQIs having [CQI] and index i CQI The third number of bits indicating the difference value between the one subband CQI among the plurality of subband CQIs among a set of CQIs having [CQI] and the wideband CQI among the first set of CQIs, and index i CQI The one subband CQI among the plurality of subband CQIs among a set of CQIs having [CQI] and index i CQI At least one of the second number of bits or the third number of bits indicating the difference value between the one subband CQI among the plurality of subband CQIs among a set of CQIs having [CQI] and -1, and the second number of bits or the third number of bits indicating the difference value between the one subband CQI among the second plurality of subband CQIs and the index i among a set of CQIs CQI At least one of the third number of bits indicating the difference value between the wideband CQI having -1 and index i CQI i is a positive integer CQI is greater than 1

[0159] In some embodiments, the payload for the second wideband CQI includes a first number of bits indicating an absolute value of the second wideband CQI, and the payload for the second subband CQI among the plurality of second subband CQIs includes a second number of bits indicating a difference value between the second subband CQI and the second wideband CQI.

[0160] In some embodiments, the payload of the second wideband CQI includes a third number of bits indicating a difference value between the second wideband CQI and the first wideband CQI, and the payload of the second subband CQI among the plurality of second subband CQIs includes at least one of the third number of bits indicating a difference value between the second subband CQI and the first wideband CQI, the second number of bits indicating a difference value between the second subband CQI and the second wideband CQI, and the third number of bits indicating a difference value between the second subband CQI and one of the plurality of first subband CQIs.

[0161] In some embodiments, the payload of the third wideband CQI includes any one of a third number of bits indicating a difference value between the third wideband CQI and the second wideband CQI, or a third number of bits indicating a difference value between the third wideband CQI and the first wideband CQI, and the payload of the third subband CQI among the plurality of third subband CQIs includes any one of a second number of bits indicating a difference value between the third subband CQI and the third wideband CQI, a third number of bits indicating a difference value between the third subband CQI and the second subband CQI, or a third number of bits indicating a difference value between the third subband CQI and the first subband CQI among the plurality of first subband CQIs.

[0162] In some embodiments, the payload of the third wideband CQI includes the first number of bits indicating the absolute value for the third wideband CQI, and the payload for the third subband CQI among the plurality of third subband CQIs includes the second or third number of bits indicating the difference value between the third subband CQI and the third wideband CQI.

[0163] In some embodiments, the first time unit is a second plurality of time units including a start time unit among the first plurality of time units and a second number of time units determined from the first plurality of time units, each time unit being a start time unit among the second plurality of time units after or after the first timing, and a time unit corresponding to the strongest one set of CQIs among the plurality of sets of CQIs, the strongest one set of CQIs including a wideband CQI or a subband CQI having a maximum value among the plurality of sets of CQIs, and the CSI report including an index value of the time unit corresponding to the strongest one set of CQIs, and is one of the above time units.

[0164] In some embodiments, receiving the CSI report includes receiving an indication field within a second portion of the CSI report, the indication field indicating the first plurality of time units. In some embodiments, the payload of the indication field is determined based on a fourth number of time units among the first plurality of time units and the number of CQI sets among the plurality of CQIs. In some embodiments, the payload of the indication field is determined based on a fifth number of time units among the second plurality of time units and the number of CQI sets among the plurality of sets of CQIs.

[0165] In some embodiments, the first set of CQIs includes a set of CQIs associated with a predetermined time unit among the first plurality of time units, the predetermined time unit including at least one of a start time unit among the first plurality of time units and a start time unit among the second plurality of time units, and the payload of the indication field is determined based on one of a result of subtracting 1 from the fourth number and a result of subtracting 1 from the number of CQI sets, and a result of subtracting 1 from the fifth number of time units within the second plurality of time units and a result of subtracting 1 from the number of CQI sets.

[0166] FIG. 11 is a schematic block diagram of an apparatus 1100 suitable for implementing some embodiments of the present disclosure. The apparatus 1100 may be regarded as another exemplary embodiment of the terminal device 110 shown in FIG. 1 or the network device 120 shown in FIG. 1. Accordingly, the apparatus 1100 may be implemented in or as at least a part of the above network device or terminal device.

[0167] As shown, apparatus 1100 includes a processor 1110, a memory 1120 coupled to the processor 1110, a suitable transmitter (TX) and receiver (RX) 1140 coupled to the processor 1110, and a communication interface coupled to the TX / RX 1140. The memory 1120 stores at least a portion of program 1130. The TX / RX 1140 is used for two-way communication. The TX / RX 1140 has at least one antenna to facilitate communication, although the access nodes referred to herein may actually have multiple antennas. The communication interface may represent any interface necessary for communication with other network elements, such as an X2 interface for two-way communication between gNBs or eNBs, an S1 interface for communication between a Mobility Management Entity (MME) / Serving Gateway (S-GW) and an eNB, a Un interface for communication between a gNB or eNB and a relay node (RN), or a Uu interface for communication between a gNB or eNB and a terminal device.

[0168] It is assumed that program 1130 includes program instructions that, when executed by the associated processor 1110 as described herein with reference to FIGS. 2-10, enable apparatus 1100 to operate in accordance with embodiments of the present disclosure. Embodiments herein may be implemented by computer software executable by the processor 1110 of apparatus 1100, or by hardware, or by a combination of software and hardware. The processor 1110 may be configured to implement various embodiments of the present disclosure. Further, the combination of the processor 1110 and the memory 1120 may form processing means 1150 suitable for implementing various embodiments of the present disclosure.

[0169] Memory 1120 may be of any type suitable for a local technology network and, by way of non-limiting example, may be implemented using any suitable data storage technology such as a non-transitory computer-readable storage medium, a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, a fixed memory, and a removable memory. Only one memory 1120 is shown within device 1100, but there may be several physically different memory modules within device 1100. Processor 1110 may be of any type suitable for a local technology network and, by way of non-limiting example, may include one or more of a general-purpose computer, a dedicated computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Device 1200 may have an application-specific integrated circuit chip that is temporally dependent on a clock that synchronizes a plurality of processors, e.g., a main processor.

[0170] In some embodiments, the terminal device comprises circuitry configured to execute method 900.

[0171] In some embodiments, the network device comprises circuitry configured to execute method 1000.

[0172] The components included in the devices and / or apparatuses of the present disclosure may be implemented in various forms including software, hardware, firmware, or any combination thereof. In one embodiment, one or more units can be realized using software and / or firmware such as machine-executable instructions stored on a storage medium. In addition to or instead of the machine-executable instructions, some or all of the units within the device and / or apparatus may be implemented at least partially by one or more hardware logic components. By way of non-limiting example, exemplary types of hardware logic components that can be used include field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system on chips (SOCs), complex programmable logic devices (CPLDs), and the like.

[0173] Overall, various embodiments of the present disclosure may be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software executable by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are illustrated and described using block diagrams, flowcharts, or some other pictorial representation, it should be understood that the blocks, devices, systems, technical terminal devices, or methods described herein may be implemented, by way of non-limiting example, in hardware, software, firmware, dedicated circuitry or logic, general purpose hardware or a controller or other computing device, or any combination thereof.

[0174] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in program modules, that are executed within an apparatus on a target physical processor or virtual processor to perform the process or method described above with reference to any one of FIGS. 2 to 10. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functions of the program modules may be combined or divided among the program modules as needed. The machine-executable instructions of the program modules may be executed within a local or distributed apparatus. In a distributed apparatus, the program modules may be located in both local and remote storage media.

[0175] The program code for executing the method of the present disclosure may be described in any combination of one or more programming languages. These program codes are provided to a processor or controller of a general-purpose computer, a dedicated computer, or other programmable data processing equipment, and when executed by the processor or controller, the program codes implement the functions / operations specified in the flowchart and / or block diagram. The program code may be executed entirely on the machine, partially on the machine, as an independent software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0176] The above program code may be implemented on a machine-readable medium, which may be any tangible medium that can be utilized by or associated with an instruction execution system, apparatus, or device and that can contain or store a program for use by or in connection with the same. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing media. More specific examples of the machine-readable storage medium may include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0177] Note that although the operations have been described in a particular order, it should be understood that such operations may be performed in the particular order shown or in sequential order, or that all of the operations described may be required to obtain the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although details of some specific embodiments are included in the above discussion, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Some of the features described in the context of individual embodiments may be combined in a single embodiment to be implemented. Conversely, the various features described in the context of a single embodiment may be implemented separately in multiple embodiments or in any suitable sub-combination.

[0178] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the present disclosure as defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as exemplary forms of implementing the claims.

[0179] In short, embodiments of the present disclosure can provide the following solutions.

[0180] A communication method includes, at a terminal device, determining a first set of channel quality indicators (CQIs) conditional on a first precoding matrix indicator (PMI) corresponding to a first time unit, wherein a second timing of the first time unit is after a first timing of a first time interval for reporting channel state information (CSI), and transmitting a CSI report including the first set of CQIs and the first PMI to a network device within the first time interval.

[0181] In one embodiment, the first time unit is the first time unit after a third timing or among subsequent time units, the third timing including at least one of the first timing and a start or end of a time interval corresponding to an index determined based on the first index + M of the first time interval, and M is a non-negative integer.

[0182] In one embodiment, the length of M time intervals is equal to or greater than a time interval for a network device to decode a CSI report.

[0183] In one embodiment, the first set of CQIs includes at least one of a first wideband CQI and a first plurality of subband CQIs.

[0184] In one embodiment, at least one of the first wideband CQI and the first plurality of sub-band CQIs is determined based on at least two PMIs including the first PMI.

[0185] In one embodiment, at least one of the first wideband CQI and the first plurality of sub-band CQIs is determined based on the first PMI.

[0186] In one embodiment, the CSI report includes a plurality of sets of CQIs associated with a first plurality of time units, the plurality of sets of CQIs includes the first set of CQIs, and one set of CQIs among the plurality of sets of CQIs is associated with a time unit among the first plurality of time units and includes at least one of a wideband CQI and a plurality of sub-band CQIs, and at least one of the wideband CQI and the plurality of sub-band CQIs is determined based on a PMI corresponding to the associated time unit.

[0187] In one embodiment, the CSI report further includes at least one of a second set of CQIs associated with a second time unit and a third set of CQIs associated with a third time unit, the second time unit is different from the first time unit, and the third time unit is different from the second time unit.

[0188] In one embodiment, the second set of CQIs includes at least one of a second wideband CQI and a second plurality of sub-band CQIs, at least one of the second wideband CQI and the second plurality of sub-band CQIs is determined based on a second PMI corresponding to the second time unit, the third set of CQIs includes at least one of a third wideband CQI and a third plurality of sub-band CQIs, and at least one of the third wideband CQI and the third plurality of sub-band CQIs is determined based on a third PMI corresponding to the third time unit.

[0189] In one embodiment, transmitting the CSI report includes transmitting the CQI of the first set within a first portion of the CSI report and transmitting at least one of the CQI of the second set and the CQI of the third set within a second portion of the CSI report.

[0190] In one embodiment, transmitting the CSI report includes at least one of transmitting the CQI of the second set in response to the difference between the CQI of the second set and the CQI of the first set exceeding a first threshold value, and transmitting the CQI of the third set in response to the difference between the CQI of the third set and the CQI of the second set exceeding a second threshold value.

[0191] In one embodiment, the payload of the wideband CQI of one set of CQIs having index iCQI among the plurality of sets of CQIs includes at least one of: the first number of bits indicating the value for the wideband CQI of one set of CQIs having index iCQI; the third number of bits indicating the difference value between the wideband CQI of one set of CQIs having index iCQI and the wideband CQI of the first set of CQIs; or the third number of bits indicating the difference value between the wideband CQI of one set of CQIs having index iCQI and the wideband CQI of one set of CQIs having index iCQI−1. The payload for one subband CQI among the plurality of subband CQIs of one set of CQIs having index iCQI includes at least one of: the second number of bits indicating the difference value between the one subband CQI among the plurality of subband CQIs of one set of CQIs having index iCQI and the wideband CQI of one set of CQIs having index iCQI; the third number of bits indicating the difference value between the one subband CQI among the plurality of subband CQIs of one set of CQIs having index iCQI and the wideband CQI of the first set of CQIs; the second or third number of bits indicating the difference value between the one subband CQI among the plurality of subband CQIs of one set of CQIs having index iCQI and the one subband CQI among the plurality of subband CQIs of one set of CQIs having index iCQI−1; and the third number of bits indicating the difference value between the one subband CQI among the second plurality of subband CQIs and the wideband CQI of one set of CQIs having index iCQI−1. iCQI is a positive integer and iCQI is greater than 1.

[0192] In one embodiment, the payload for the second wideband CQI includes the first number of bits indicating the absolute value for the second wideband CQI. The payload for the second subband CQI among the second plurality of subband CQIs includes the second number of bits indicating the difference value between the second subband CQI and the second wideband CQI.

[0193] In one embodiment, the payload of the second wideband CQI includes a third number of bits indicating a difference value between the second wideband CQI and the first wideband CQI, and the payload of the second sub-band CQI among the plurality of second sub-band CQIs includes the third number of bits indicating a difference value between the second sub-band CQI and the first wideband CQI, the second number of bits indicating a difference value between the second sub-band CQI and the second wideband CQI, and the third number of bits indicating a difference value between the second sub-band CQI and one of the first plurality of sub-band CQIs, including at least one of them.

[0194] In one embodiment, the payload of the third wideband CQI includes either the third number of bits indicating a difference value between the third wideband CQI and the second wideband CQI or the third number of bits indicating a difference value between the third wideband CQI and the first wideband CQI, and the payload of the third sub-band CQI among the plurality of third sub-band CQIs includes either the second number of bits indicating a difference value between the third sub-band CQI and the third wideband CQI, the third number of bits indicating a difference value between the third sub-band CQI and the second sub-band CQI, or the third number of bits indicating a difference value between the third sub-band CQI and the first sub-band CQI among the first plurality of sub-band CQIs, including any one of them.

[0195] In one embodiment, the payload of the third wideband CQI includes the first number of bits indicating an absolute value for the third wideband CQI, and the payload for the third sub-band CQI among the plurality of third sub-band CQIs includes the second or third number of bits indicating a difference value between the third sub-band CQI and the third wideband CQI.

[0196] In one embodiment, the first time unit is a second plurality of time units including a start time unit among the first plurality of time units and a second number of time units determined from the first plurality of time units, where each time unit is a start time unit among the second plurality of time units that are after or after that first timing, and a time unit corresponding to the strongest one set of CQI among the plurality of sets of CQI, where the strongest one set of CQI includes a broadband CQI or a sub-band CQI having a maximum value among the plurality of sets of CQI, and the CSI report includes an index value of the time unit corresponding to the strongest one set of CQI, and is one of the time unit and the like.

[0197] In one embodiment, transmitting the CSI report includes transmitting an indication field within a second part of the CSI report, where the indication field indicates the first plurality of time units.

[0198] In one embodiment, the payload of the indication field is determined based on a fourth number of time units among the first plurality of time units and a number of CQI sets among the plurality of CQI.

[0199] In one embodiment, the payload of the indication field is determined based on a fifth number of time units among the second plurality of time units and a number of CQI sets among the plurality of sets of CQI.

[0200] In one embodiment, the first set of CQI includes a set of CQI associated with a predetermined time unit among the first plurality of time units, where the predetermined time unit includes at least one of a start time unit among the first plurality of time units, a start time unit among the second plurality of time units, and the time unit corresponding to the strongest one set of CQI, and the payload of the indication field includes at least one of a result of subtracting 1 from the fourth number and a result of subtracting 1 from the number of CQI sets, and a result of subtracting 1 from the fifth number of time units within the second plurality of time units and a result of subtracting 1 from the number of CQI sets.

[0201] A communication method includes, in a network device, receiving, from a terminal device, a channel state information (CSI) report including a first set of channel quality indicators (CQIs) and a first precoding matrix indicator (PMI) within a first time interval, where the first set of CQIs is conditional on the first PMI, the first PMI corresponds to a first time unit, and a second timing of the first time unit is after a first timing of the first time interval for reporting the CSI.

[0202] In one embodiment, the first time unit is the first time unit among those after a third timing or subsequent time units, the third timing includes at least one of the first timing and a start or end of a time interval corresponding to an index determined based on the first index + M of the first time interval, and M is a non-negative integer.

[0203] In one embodiment, the length of M time intervals is equal to or greater than the time interval for the network device to decode the CSI report.

[0204] In one embodiment, the first set of CQIs includes at least one of a first wideband CQI and a first plurality of subband CQIs.

[0205] In one embodiment, at least one of the first wideband CQI and the first plurality of subband CQIs is determined based on at least two PMIs including the first PMI.

[0206] In one embodiment, at least one of the first wideband CQI and the first plurality of subband CQIs is determined based on the first PMI.

[0207] In one embodiment, the CSI report includes a plurality of sets of CQIs associated with a first plurality of time units. The plurality of sets of CQIs includes the first set of CQIs. One set of CQIs among the plurality of sets of CQIs is associated with a time unit among the first plurality of time units and includes at least one of a broadband CQI and a plurality of sub-band CQIs. The at least one of the broadband CQI and the plurality of sub-band CQIs is determined based on a PMI corresponding to the associated time unit.

[0208] In one embodiment, the CSI report further includes at least one of a second set of CQIs associated with a second time unit and a third set of CQIs associated with a third time unit. The second time unit is different from the first time unit, and the third time unit is different from the second time unit.

[0209] In one embodiment, the second set of CQIs includes at least one of a second broadband CQI and a second plurality of sub-band CQIs. The at least one of the second broadband CQI and the second plurality of sub-band CQIs is determined based on a second PMI corresponding to the second time unit. The third set of CQIs includes at least one of a third broadband CQI and a third plurality of sub-band CQIs. The at least one of the third broadband CQI and the third plurality of sub-band CQIs is determined based on a third PMI corresponding to the third time unit.

[0210] In one embodiment, receiving the CSI report includes receiving the first set of CQIs in a first portion of the CSI report and receiving at least one of the second set of CQIs and the third set of CQIs in a second portion of the CSI report.

[0211] In one embodiment, the payload of the wideband CQI of one set of CQIs having index iCQI among the plurality of sets of CQIs includes at least one of: the first number of bits indicating a value for the wideband CQI of one set of CQIs having index iCQI; the third number of bits indicating a difference value between the wideband CQI of one set of CQIs having index iCQI and the wideband CQI of the first set of CQIs; and the third number of bits indicating a difference value between the wideband CQI of one set of CQIs having index iCQI and the wideband CQI of one set of CQIs having index iCQI−1. The payload of one subband CQI among the plurality of subband CQIs of one set of CQIs having index iCQI includes at least one of: the second number of bits indicating a difference value between the one subband CQI of the plurality of subband CQIs of one set of CQIs having index iCQI and the wideband CQI of one set of CQIs having index iCQI; the third number of bits indicating a difference value between the one subband CQI of the plurality of subband CQIs of one set of CQIs having index iCQI and the wideband CQI of the first set of CQIs; the second or third number of bits indicating a difference value between the one subband CQI of the plurality of subband CQIs of one set of CQIs having index iCQI and the one subband CQI of one set of CQIs having index iCQI−1; and the third number of bits indicating a difference value between the one subband CQI of the second plurality of subband CQIs and the wideband CQI of one set of CQIs having index iCQI−1. iCQI is a positive integer and iCQI is greater than 1.

[0212] In one embodiment, the payload for the second wideband CQI includes the first number of bits indicating the absolute value for the second wideband CQI, and the payload for the second subband CQI among the second plurality of subband CQIs includes the second number of bits indicating the difference value between the second subband CQI and the second wideband CQI.

[0213] In one embodiment, the payload of the second wideband CQI includes a third number of bits indicating a difference value between the second wideband CQI and the first wideband CQI. The payload of the second sub-band CQI among the plurality of second sub-band CQIs includes at least one of: the third number of bits indicating a difference value between the second sub-band CQI and the first wideband CQI; the second number of bits indicating a difference value between the second sub-band CQI and the second wideband CQI; and the third number of bits indicating a difference value between the second sub-band CQI and one of the first plurality of sub-band CQIs.

[0214] In one embodiment, the payload of the third wideband CQI includes either a third number of bits indicating a difference value between the third wideband CQI and the second wideband CQI, or a third number of bits indicating a difference value between the third wideband CQI and the first wideband CQI. The payload of the third sub-band CQI among the plurality of third sub-band CQIs includes either: the second number of bits indicating a difference value between the third sub-band CQI and the third wideband CQI; the third number of bits indicating a difference value between the third sub-band CQI and the second sub-band CQI; or the third number of bits indicating a difference value between the third sub-band CQI and the first sub-band CQI among the first plurality of sub-band CQIs.

[0215] In one embodiment, the payload of the third wideband CQI includes a first number of bits indicating an absolute value of the third wideband CQI. The payload for the third sub-band CQI among the plurality of third sub-band CQIs includes a second or third number of bits indicating a difference value between the third sub-band CQI and the third wideband CQI.

[0216] In one embodiment, the first time unit is a second plurality of time units including a start time unit among a first plurality of time units and a second number of time units determined from the first plurality of time units, each time unit being a start time unit among the second plurality of time units after or after the first timing and a time unit corresponding to the strongest one set of CQI among the plurality of sets of CQI, the strongest one set of CQI including a wideband CQI or a subband CQI having a maximum value among the plurality of sets of CQI, and the CSI report being one of the time unit including an index value of the time unit corresponding to the strongest one set of CQI.

[0217] In one embodiment, receiving the CSI report includes receiving an indication field within a second portion of the CSI report, the indication field indicating the first plurality of time units.

[0218] In one embodiment, the payload of the indication field is determined based on a fourth number of time units among the first plurality of time units and the number of sets of CQI among the plurality of CQI.

[0219] In one embodiment, the payload of the indication field is determined based on a fifth number of time units among the second plurality of time units and the number of sets of CQI among the plurality of sets of CQI.

[0220] In one embodiment, the first set of CQI includes a set of CQI associated with a predetermined time unit among the first plurality of time units, the predetermined time unit including at least one of a start time unit among the first plurality of time units, a start time unit among the second plurality of time units, and the time unit corresponding to the strongest one set of CQI, and the payload of the indication field includes at least one of a result of subtracting 1 from the fourth number and a result of subtracting 1 from the number of sets of CQI, and a result of subtracting 1 from the fifth number of time units within the second plurality of time units and a result of subtracting 1 from the number of sets of CQI.

[0221] Hereinafter, the terms "transmission opportunity", "reception opportunity", "repetition", "transmission", "reception", "PDSCH transmission opportunity", "PDSCH repetition", "PUSCH transmission opportunity", "PUSCH repetition", "PUCCH opportunity", "PUCCH repetition", "repetitive transmission", "repetitive reception", "PDSCH transmission", "PDSCH reception", "PUSCH transmission", "PUSCH reception", "PUCCH transmission", "PUCCH reception", "RS transmission", "RS reception", "communication", "transmission", and "reception" may be used interchangeably. The terms "TCI state", "set of QCL parameters", "QCL parameter", "QCL assumption", and "QCL configuration" may be used interchangeably. The terms "TCI field", "TCI state field", and "transmission configuration indication" may be used interchangeably. The terms "transmission opportunity", "transmission", "repetition", "reception", "reception opportunity", "monitoring opportunity", "PDCCH monitoring opportunity", "PDCCH transmission opportunity", "PDCCH transmission", "PDCCH candidate", "PDCCH reception opportunity", "PDCCH reception", "search space", "CORESET", "multi-chance", and "PDCCH repetition" may be used interchangeably. Hereinafter, the terms "PDCCH repetition", "repetitive PDCCH", "repetitive PDCCH signal", "PDCCH candidates configured for the same scheduling", "PDCCH", "PDCCH candidate", and "linked PDCCH candidate" may be used interchangeably. The terms "DCI" and "DCI format" may be used interchangeably. In some embodiments, the embodiments of the present disclosure may be applied to PDSCH and PUSCH scheduling. Hereinafter, PDSCH scheduling will be described as an example. For example, the embodiments of the present disclosure may be applied to PUSCH by replacing "transmission" with "reception" and / or "reception" with "transmission". The terms "PDSCH" and "PUSCH" may be used interchangeably. The terms "transmission" and "reception" may be used interchangeably.The terms "common beam", "common beam update / indication", "integrated TCI state", "integrated TCI state update / indication", "beam indication", "TCI state indication", "TCI_state_r17", "tci_StateId_r17", "TCI_state_r17 indicating the integrated TCI state", "TCI state shared / applied for all or a subset of CORESETs on PDSCH and UE-specific reception", "Rel-17 TCI state", "TCI state having tci_StateId_r17", "TCI state configured for TCI state update in the integrated TCI framework", "TCI state indicated in DCI for common beam update / indication", and "TCI state indicated in DCI and applied to all / subsets of CORESETs and PDSCH" may be used interchangeably. The terms "subset of CORESET", "subset of TCI state", "subset of integrated TCI state", "subset of downlink (integrated) TCI state", and "subset of combined (integrated) TCI state" may be used interchangeably. The terms "subset of PUCCH", "subset of TCI state", "subset of integrated TCI state", "subset of uplink (integrated) TCI state", and "subset of combined (integrated) TCI state" may be used interchangeably. The terms "precoding matrix", "precoding", "beam", "beamforming", "codebook", and "precoder" may be used interchangeably. The terms "size" and "number of PRBs" may be used interchangeably. The terms "vector", "beam", "base", and "basis" may be used interchangeably. The terms "first vector", "first beam", "first base", "spatial domain basis vector", "spatial domain vector", "spatial domain basis", "spatial domain base", and "first basis" may be used interchangeably. The terms "second vector", "second beam", "second base", "frequency domain basis vector", "frequency domain vector", "frequency domain basis", "frequency domain base", and "second basis" may be used interchangeably.The terms "third vector", "third beam", "third base", "Doppler / time domain basis vector", "Doppler / time domain vector", "Doppler / time domain basis", "Doppler / time domain base", "Doppler domain basis vector", "Doppler domain vector", "Doppler domain basis", "Doppler domain base", "time domain basis vector", "time domain vector", "time domain basis", "time domain base", and "third base" may be used interchangeably. The terms "index", "indicator", "indication", "field", "bit field", and "bitmap" may be used interchangeably. The terms "physical resource block", "resource block", "PRB", and "RB" may be used interchangeably. The terms "bit size", "size of bit", "number of bits", "size of field", and "field size" may be used interchangeably. The terms "time unit", "Doppler unit", "unit in time domain", "unit in Doppler domain", "time point", and "unit for third vector" may be used interchangeably.

[0222] As described above, precoding is a generalized beamforming method that supports multi-layer transmission in a MIMO system. Precoding is a technique that utilizes transmit diversity by weighting information streams, i.e., the transmitter transmits the encoded information to the receiver in order to achieve prior knowledge of the channel. By using precoding, multiple streams are transmitted from the transmit antennas with appropriate weighting independently for each antenna so that the throughput is maximized at the receiver output. The terms "precoding matrix", "precoding", "beam", "codebook", and "precoder" may hereinafter be used interchangeably. Also, it is possible to enable uplink transmission having eight anaports to support four or more layers.

[0223] To facilitate precoding, CSI (Channel State Information) is measured by a terminal device and reported to a network device. The terminal device obtains CSI information by measuring one or more downlink reference signals (e.g., one or more cell-specific reference signals, or CSI-RS, or CSI-RS for tracking, or tracking RS (TRS)). The CSI reported by the terminal device can reflect the channel quality of the PRBs (physical resource blocks) assigned to the specific terminal device, and can also reflect the channel quality of the PRBs not assigned to the specific terminal device. The CSI report may be periodic or aperiodic (triggered by an event).

[0224] In some embodiments, the CSI may include at least one of a CQI (Channel Quality Indicator), a PMI (Precoding Matrix Indicator), a CSI-RS resource indicator (CRI), a synchronization signal / physical broadcast channel (SS / PBCH) block resource indicator (SSBRI), a layer indicator (LI), a layer-1 reference signal received power (L1-RSRP), a layer-1 signal-to-noise and interference ratio (L1-SINR), a capabilityIndex, a capabilitysetIndex, a PTI (Precoding Type Indicator), and an RI (Rank Indicator). The RI indicates the transmission rank proposed by the terminal device to the network device for use in downlink transmission. In other words, the RI is the number of layers proposed by the terminal device to the network device for use in downlink transmission. The PMI indicates the precoder matrix proposed by the terminal device for use in downlink transmission by the network device. The precoder matrix is selected based on the assumption that the "number of layers indicated by the reported RI" is used. The PMI reported by the terminal device can be selected only from the codebook defined by the 3GPP (registered trademark) specifications.

[0225] Regarding the PMI proposal received from the terminal device, the network device only needs to send a confirmation response message to the terminal device, and may adopt the last reported PMI proposal for further downlink transmission with the terminal device. When the terminal device receives this confirmation response message, it demodulates and decodes the corresponding DL-SCH transmission using the settings proposed to the network device. Since there is frequency selectivity when the UE calculates the PMI, the network device may need to use different precoder matrices for different combinations of RBs. Thus, the CSI report from the terminal device may be used to facilitate precoding and improve communication performance.

[0226] In some embodiments, the network device 120 may be configured to have one or two or three or four TRPs / panels 120-1 and / or 120-2 and / or 120-3 and / or 120-4 (collectively referred to as TRP 120 or individually referred to as TRP 120). The network 100 further includes a terminal device 110 served by the network device 120. The serving area of the network device 120 is referred to as cell 101 and / or cell 102. It should be understood that the numbers of network devices, terminal devices, and TRPs are for illustrative purposes only and do not imply any limitation to the present disclosure. The network 100 may include any suitable number of network devices, terminal devices, and / or serving cells suitable for implementing the embodiments of the present disclosure. Although not shown, it should be understood that one or more terminal devices may be within cell 101 and / or cell 102 and be served by the network device 120.

[0227] In some scenarios, carrier aggregation (CA), where two or more CCs are aggregated to support a wider bandwidth, can be supported in network 100. For example, network device 120 may provide terminal device 110 with a plurality of serving cells including one primary cell (Pcell or Pscell or Spcell) 101 corresponding to a primary CC and at least one secondary cell (Scell) 102 corresponding to at least one secondary CC. It should be understood that the number of Scells is for illustrative purposes and does not imply any limitation to the present disclosure. Network 100 may include any suitable number of Scells suitable for implementing embodiments of the present disclosure.

[0228] In some other scenarios, terminal device 110 may establish connections with two different network devices, and thus can utilize the radio resources of the two network devices. These two network devices may be defined as a master network device and a secondary network device, respectively. The master network device may provide a group of serving cells, also referred to as a "Master Cell Group (MCG)". The secondary network device may also provide a group of serving cells, also referred to as a "Secondary Cell Group (SCG)". In the case of dual connection operation, the term "Special Cell (Spcell)" may refer to the Pcell of the MCG or the primary Scell (Pscell) of the SCG, depending on whether the terminal device 110 is associated with the MCG or the SCG, respectively. In cases other than dual connection operation, the term "SpCell" may refer to the PCell.

[0229] In one embodiment, the terminal device 110 may be connected to a first network device and a second network device. One of the first network device and the second network device may be within the master node, and the other may be within the secondary node. The first network device and the second network device may use different radio access technologies (RATs). In one embodiment, the first network device may be a first RAT device, and the second network device may be a second RAT device. In one embodiment, the first RAT device may be an eNB, and the second RAT device may be a gNB. Information regarding different RATs may be transmitted from at least one of the first network device and the second network device to the terminal device 110. In one embodiment, the first information may be transmitted from the first network device to the terminal device 110, and the second information may be transmitted from the second network device directly or via the first network device to the terminal device 110. In one embodiment, information regarding the settings of the terminal device set by the second network device may be transmitted from the second network device via the first network device. Information regarding the resetting of the terminal device set by the second network device may be transmitted from the second network device directly or via the first network device to the terminal device. This information may be transmitted via any one of radio resource control (RRC) signaling, medium access control (MAC) control element (CE), or downlink control information (DCI).

[0230] As used herein, the term "terminal device" refers to any device having wireless or wired communication capabilities. Examples of terminal devices include user equipment (UE), personal computers, desktop computers, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, tablets, wearable devices, Internet of Things (IoT) devices, any Internet of Everything (IoE) device, machine type communication (MTC) devices, ultra-reliable and low-latency communication (URLLC) devices, in-vehicle devices for V2X communication where X means a pedestrian, a vehicle, or infrastructure / network, or image acquisition devices such as digital cameras, game devices, music storage and playback devices, or Internet devices enabling wireless or wired Internet access and browsing, etc., but are not limited thereto. Hereinafter, for the sake of explanation, some embodiments will be described with reference to a UE as an example of the terminal device 110.

[0231] The term "network device" or "base station" (BS) as used herein means a device capable of providing or hosting a cell or coverage with which a terminal device can communicate. Examples of network devices include Node B (NodeB or NB), evolved Node B (eNodeB or eNB), next-generation Node B (gNB), transmission and reception point (TRP), remote radio unit (RRU), radio head (RH), remote radio head (RRH), femto node, pico node, and other low-power nodes, but are not limited thereto. The term "TRP" means an antenna array (having one or more antenna elements) available by a network device located at a specific geographical location. For example, a network device may be coupled to a plurality of TRPs at different geographical locations to achieve better coverage. It should be understood that a TRP may also be referred to as a "panel", and a "panel" may also refer to an antenna array or a group of antennas (having one or more antenna elements).

[0232] In one embodiment, the terminal device 110 may be connected to a first network device and a second network device. One of the first network device and the second network device may be within a master node, and the other may be within a secondary node. The first network device and the second network device may use different radio access technologies (RATs). In one embodiment, the first network device may be a first RAT device, and the second network device may be a second RAT device. In one embodiment, the first RAT device may be an eNB, and the second RAT device may be a gNB. Information regarding different RATs may be transmitted from at least one of the first network device and the second network device to the terminal device 110. In one embodiment, the first information may be transmitted from the first network device to the terminal device 110, and the second information may be transmitted from the second network device directly or via the first network device to the terminal device 110. In one embodiment, information regarding the settings of the terminal device set by the second network device may be transmitted from the second network device via the first network device. Information regarding the re - settings of the terminal device set by the second network device may be transmitted from the second network device directly or via the first network device to the terminal device. This information may be transmitted via any one of radio resource control (RRC) signaling, media access control (MAC) control element (CE), or downlink control information (DCI).

[0233] In some embodiments, the network device 120 may communicate with the terminal device 110 via a first TRP (e.g., TRP 120-1) and / or a second TRP (e.g., TRP 120-2) and / or a third TRP (e.g., TRP 120-3) and / or a fourth TRP (e.g., TRP 120-4). For example, the first TRP and / or the second TRP and / or the third TRP and / or the fourth TRP may be included in the same serving cell or different serving cells provided by the network device 120. Although some embodiments of the present disclosure have been described with reference to the first TRP and / or the second TRP and / or the third TRP and / or the fourth TRP within the same serving cell provided by the network device 120, these embodiments are for illustrative purposes only, to help those skilled in the art understand and implement the present disclosure, and do not imply any limitation on the scope of the present disclosure. It should be understood that the content of the present disclosure described herein can be implemented in various ways different from the methods described below.

[0234] In the communication network 100, the network device 120 can communicate data and control information to the terminal device 110, and the terminal device 110 can also communicate data and control information to the network device 120. The link from the network device 120 to the terminal device 110 is referred to as the downlink (DL), and the link from the terminal device 110 to the network device 120 is referred to as the uplink (UL).

[0235] Communication in network 100 may comply with any suitable standard, including but not limited to Long Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), and Global System for Mobile Communications (GSM). Further, the communication may be performed according to any generation of communication protocol known currently or developed in the future. Examples of communication protocols include, but are not limited to, the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, and fifth generation (5G) communication protocols.

[0236] In some embodiments, the first TRP and / or the second TRP and / or the third TRP and / or the fourth TRP may be explicitly associated with identities set by different upper layers. For example, the upper layer-set identities may be associated with a Control Resource Set (CORESET), a reference signal (RS), or a Transmission Configuration Indication (TCI) state used to distinguish transmissions between different TRPs 120 and the terminal device 110.

[0237] As used herein, the term "slot" means a dynamic scheduling unit. One slot contains a predetermined number of symbols. For example, the number of symbols in one slot may be 12 or 14. The term "sub-slot" may refer to a plurality of symbols. For example, the number of symbols in one sub-slot may be 1, 2, 4, 7, or 14. A sub-slot may contain fewer symbols than one slot. The slot as used herein may refer to a normal slot containing a predetermined number of symbols and a sub-slot containing fewer symbols than the predetermined number of symbols.

[0238] In some embodiments, the terminal device 110 may receive at least one setting regarding the codebook from the network device 120. The at least one setting regarding the codebook includes a plurality of CSI-RS resources, a plurality of antenna ports for one CSI-RS resource, at least one parameter regarding the antenna port setting, a setting regarding the codebook type, a setting regarding the reporting type, at least one parameter regarding the codebook, the number of physical resource blocks (PRBs) within a bandwidth part (BWP), the number of a plurality of first sub-bands, the size of one first sub-band, the number of PRBs of one first sub-band, the number of a plurality of second sub-bands (e.g., represented as

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[0239] In some embodiments, the number of the plurality of CSI-RS resources may be a positive integer. For example, the number of the plurality of CSI-RS resources may be 1 or more and 64 or less. In some embodiments, the number of the plurality of antenna ports for one CSI-RS resource may be a positive integer. For example, the number of the plurality of antenna ports for one CSI-RS resource may be at least one of {1, 2, 4, 8, 12, 16, 24, 32}.

[0240] In some embodiments, the terminal device 110 may transmit a plurality of layers and at least one codebook indicator to the network device 120 based on the at least one setting for the codebook. In some embodiments, the at least one codebook indicator may include at least one of one or more indicators for a plurality of first vectors, one or more indicators for a plurality of second vectors, one or more indicators for a plurality of third vectors, a field for a plurality of first amplitude coefficients corresponding to one layer having an index, a field for a plurality of second amplitude coefficients corresponding to one layer having an index, a field for a plurality of phase coefficients corresponding to one layer having an index, a bitmap for indicating non-zero coefficients corresponding to one layer having an index, and an indicator of the strongest coefficient corresponding to one layer having an index. In some embodiments, the bitmap for indicating non-zero coefficients may indicate which coefficients in the field for the plurality of second amplitude coefficients are non-zero or have been reported. In some embodiments, the bitmap for indicating non-zero coefficients may indicate which coefficients in the field for the plurality of phase coefficients are non-zero or have been reported.

[0241] In some embodiments, the at least one codebook indicator may include at least one of one or more fields for the plurality of second vectors and one or more fields for the plurality of third vectors. In some embodiments, one field for the plurality of second vectors may correspond to one indicator for the plurality of second vectors. In some embodiments, one field for the plurality of third vectors may correspond to one indicator for the plurality of third vectors. In some embodiments, each of the one or more fields for the plurality of second vectors may correspond to one layer with an index. In some embodiments, each of the one or more fields for the plurality of third vectors may correspond to one layer with an index. In some embodiments, the one or more fields for the plurality of second vectors may correspond to each layer among the plurality of layers. For example, the one or more fields for the plurality of second vectors may be the same for each layer among the plurality of layers. In some embodiments, the one or more fields for the plurality of third vectors may correspond to each layer among the plurality of layers. For example, the one or more fields for the plurality of third vectors may be the same for each layer among the plurality of layers.

[0242] In some embodiments,

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[0243] In some embodiments, the terminal device 110 may be set to have the number of physical resource blocks (PRBs) for a bandwidth part (BWP), or may be set to have a size for the BWP. In some embodiments, the number of PRBs for the BWP (e.g.,

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[0244] In some embodiments, the terminal device 110 may be set to have a start position of the BWP (e.g.,

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[0245] In some embodiments, the start position of the BWP and the number of PRBs for the BWP may be set within one upper layer parameter.

[0246] In some embodiments, the first sub - band may correspond to a sub - band for a channel quality indicator (CQI), or a CQI sub - band, or a CSI sub - band. For example, it corresponds to one time unit.

[0247] In some embodiments, the size of one first sub - band or the number of PRBs of one first sub - band is

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[0248] In some embodiments, the at least one parameter for the antenna port setting may include at least one of the number of the plurality of CSI-RS resources, the number of antenna ports for one CSI-RS resource, the first plurality of antenna port groups, the number of the first plurality of antenna port groups, the number of antenna ports within one antenna port group, the first parameter of the antenna port setting, and the second parameter of the antenna port setting. For example, one antenna port group may correspond to a TRP or the antenna ports of a TRP. In some embodiments, one antenna port group may correspond to one CSI-RS resource. In some embodiments, the number of antenna ports may be the same for each CSI-RS resource among the plurality of CSI-RS resources.

[0249] In some embodiments, the at least one setting for the codebook may include a plurality of antenna ports within one antenna port group or for one CSI-RS resource. In some embodiments, the number of the plurality of antenna ports within one antenna port group or for one CSI-RS resource (e.g., represented as P) may be at least one of {1, 2, 4, 6, 8, 12, 16, 24, 32}. In some embodiments, the number of antenna ports within each antenna port group or for each CSI-RS resource among the plurality of CSI-RS resources may be the same. For example, P may be a positive integer. For example, P may be at least one of {1, 2, 4, 6, 8, 12, 16, 24, 32}.

[0250] In some embodiments, the terminal device may receive at least one of the plurality of CSI-RS resources based on the number of antenna ports for the at least one CSI-RS resource.

[0251] In some embodiments, the value of the first parameter of the antenna port setting may be represented as N1. For example, N1 may be a positive integer. For example, N1 may be at least one of {2, 3, 4, 6, 8, 12, 16}. In some embodiments, the value of the second parameter of the antenna port setting may be represented as N2. For example, N2 may be a positive integer. For example, N2 may be at least one of {1, 2, 3, 4}. In some embodiments, the first parameter of the antenna port setting and the second parameter of the antenna port setting may be set within one upper layer parameter.

[0252] In some embodiments, the number of antenna ports within one antenna port group or for one CSI-RS resource may be determined based on the first parameter of the antenna port configuration and the second parameter of the antenna port configuration. In some embodiments, the number of antenna ports within one antenna port group or for one CSI-RS resource is

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[0253] In some embodiments, there may be a parameter "O1", and "O1" may represent the first discrete Fourier transform (DFT) oversampling in the first dimension. For example, "O1" may be at least one of {1, 2, 4}. For another example, "O1" may be 2 or 4. In some embodiments, there may be a parameter "O2", and "O2" may represent the second DFT oversampling in the second dimension. For example, "O2" may be at least one of {1, 2, 4}. For another example, "O2" may be 2 or 4.

[0254] In some embodiments,

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[0255] In some embodiments,

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Table 6

[0256] In some embodiments, the vector

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[0257] In some embodiments, the terminal device 110 may determine the number of layers and at least one codebook indicator based on at least one setting for the codebook, or report it to the network device 120. In some embodiments, the number of layers (for example, [Number] represented as) may be at least one of {1, 2} or {1, 2, 3, 4} or {1, 2, 3, 4, 5, 6, 7, 8}. In some embodiments, there may be multiple layers, each layer may have an index, and the layer index may be [Number] represented as [Number] may be a non - negative integer. For example, [Number] is. For example, [Number] is {1, 2, … [Number] } or {1, 2} or {1, 2, 3, 4} or {1, 2, 3, 4, 5, 6, 7, 8}, and may be at least one of them.

[0258] In some embodiments, at least one codebook indicator may include at least one of one or more indicators (or fields) for a plurality of first vectors, one or more indicators (or one or more fields) for a plurality of second vectors, one or more indicators (or fields) for a first plurality of rotations for the plurality of first vectors, one or more indicators (or fields) for a plurality of third vectors, one or more indicators (or one or more fields) for a second plurality of rotations for the plurality of third vectors, one or more indicators (or one or more fields) for the strongest coefficients, one or more indicators (or fields) for a plurality of first amplitude coefficients, one or more indicators (or one or more fields) for a plurality of second amplitude coefficients, one or more indicators (or one or more fields) for a plurality of phase coefficients, a first number of non - zero coefficients, and one or more indicators (or one or more bitmaps) for indicating non - zero coefficients.

[0259] In some embodiments, one or more indicators (or one or more bitmaps) for indicating non-zero coefficients may indicate the index of the second amplitude coefficient and / or the index of the phase coefficient, and the value of the second amplitude coefficient corresponding to the index and / or the value of the phase coefficient corresponding to the index may be non-zero. In some embodiments, one or more indicators (or one or more bitmaps) for indicating non-zero coefficients may indicate which coefficients within the one or more indicators or within a field for the plurality of second amplitude coefficients are non-zero or have been reported. In some embodiments, one or more indicators (or one or more bitmaps) for indicating non-zero coefficients may indicate which coefficients within the one or more indicators or within a field for the plurality of phase coefficients are non-zero or have been reported.

[0260] In some embodiments, one or more of at least one codebook indicator or field may be the same and may be applied to each of a plurality of layers. For example, it is layer-common. In some embodiments, each of the one or more of at least one codebook indicator or field may correspond to one layer having an index. For example, it is layer-specific.

[0261] In some embodiments, one or more indicators (or fields) for the plurality of first vectors may be the same and may be applied to each of the plurality of layers. For example, it is layer-common. In some embodiments, one or more indicators (or fields) for the plurality of first vectors may correspond to one layer having an index. For example, it is layer-specific.

[0262] In some embodiments, one or more indicators (or one or more fields) for the plurality of second vectors may be the same and may be applied to each of the plurality of layers. For example, they are layer-common. In some embodiments, one or more indicators (or the one or more fields) for the plurality of second vectors may correspond to one layer with an index. For example, they are layer-specific.

[0263] In some embodiments, one or more indicators (or fields) for the first plurality of rotations for the plurality of first vectors may be the same and may be applied to each of the plurality of layers. For example, they are layer-common. In some embodiments, one or more indicators (or fields) for the first plurality of rotations for the plurality of first vectors may correspond to one layer with an index. For example, they are layer-specific.

[0264] In some embodiments, one or more indicators (or the one or more fields) for the second plurality of rotations for the plurality of third vectors may be the same and may be applied to each of the plurality of layers. For example, they are layer-common. In some embodiments, one or more indicators (or the one or more fields) for the second plurality of rotations for the plurality of third vectors may correspond to one layer with an index. For example, they are layer-specific.

[0265] In some embodiments, one or more indicators (or the one or more fields) for the plurality of third vectors may be the same and may be applied to each of the plurality of layers. For example, they are layer-common. In some embodiments, one or more indicators (or the one or more fields) for the plurality of third vectors may correspond to one layer with an index. For example, they are layer-specific.

[0266] In some embodiments, the indicator (or field) for the strongest coefficient may be the same and may be applied to each of the plurality of layers. For example, it is layer - common. In some embodiments, the indicator (or field) for the strongest coefficient may correspond to one layer with an index. For example, it is layer - specific.

[0267] In some embodiments, one or more indicators (or the one or more fields) for the plurality of first amplitude coefficients may be the same and may be applied to each of the plurality of layers. For example, it is layer - common. In some embodiments, one or more indicators (or the one or more fields) for the plurality of first amplitude coefficients may correspond to one layer with an index. For example, it is layer - specific.

[0268] In some embodiments, one or more indicators (or one or more fields) for the plurality of phase coefficients may be the same and may be applied to each of the plurality of layers. For example, it is layer - common. In some embodiments, one or more indicators (or one or more fields) for the plurality of phase coefficients may correspond to one layer with an index. For example, it is layer - specific.

[0269] In some embodiments, one or more indicators (or one or more fields) for the plurality of second amplitude coefficients may be the same and may be applied to each of the plurality of layers. For example, it is layer - common. In some embodiments, one or more indicators (or the one or more fields) for the plurality of second amplitude coefficients may correspond to one layer with an index. For example, it is layer - specific.

[0270] In some embodiments, the one or more indicators (or fields) for indicating non-zero coefficients may be the same and may be applied to each of the plurality of layers. For example, they are layer-common. In some embodiments, the one or more indicators (or fields) for indicating non-zero coefficients may correspond to one layer with an index. For example, they are layer-specific.

[0271] In some embodiments, the first number of non-zero coefficients may be the same and may be applied to each of the plurality of layers. For example, they are layer-common. In some embodiments, the first number of non-zero coefficients may correspond to one layer with an index. For example, they are layer-specific.

[0272] In some embodiments, the number of the plurality of first vectors, the second parameter for the codebook, and the third parameter for the codebook may be set or indicated within one upper-layer parameter. In some embodiments, the fifth parameter for the codebook and the sixth parameter for the codebook may be set or indicated within one upper-layer parameter.

[0273] In some embodiments, the second parameter for the codebook may be at least one of {1 / 2, 1 / 4, 1 / 8}. In some embodiments, the third parameter for the codebook may be at least one of {1 / 4, 1 / 2, 3 / 4}. In some embodiments, the number of the plurality of first vectors (e.g.,

Number

Number

Number

[0274] In some embodiments, the third parameter for the codebook may further be based on the number of layers. In some embodiments, one upper layer parameter

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

[0275] In some embodiments, the first parameter for the codebook (e.g., [Number] represented as) may be a positive integer. For example,

Number

Number

[0276] In some embodiments, the second subband may correspond to a subband for a precoding matrix indicator (PMI) or a PMI subband.

[0277] In some embodiments, the size of one second subband or the number of PRBs of one second subband is

Number

Number

Number

Number

Number

Number

Number

Number

[0278] In some embodiments, the number of the plurality of second sub-bands

Number

Number

Number

Number

Number

Number

Number

Number

[0279] In some embodiments, [Number] If it is the case, one precoding matrix may be indicated for each first subband. In some embodiments, [Number] If it is the case, for one first subband that is not the first / starting subband or the last / ending subband among the plurality of first subbands within the BWP, for one subband among the plurality of first subbands, two precoding matrices may be indicated. For example, the first precoding matrix corresponds to the first [Number] number of PRBs, and the second precoding matrix corresponds to the last [Number] number of PRBs. In some embodiments, [Number] If it is the case, for one first subband that is the first / starting subband or the last / ending subband among the plurality of first subbands within the BWP, [Number] If so, one precoding matrix may be indicated corresponding to the first / starting subband among the plurality of first subbands. In some embodiments,

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

[0280] In some embodiments, the number

Number

Number

Number

[0281] In some embodiments, nchoosek may be a function that selects k values from n values. In some embodiments, nchoosek(a, b) = a! / (b! * (a - b)!). In some embodiments, "!" may be a factorial. In some embodiments, a! = 1 * 2 * … * (a - 1) * a.

[0282] In some embodiments, at least one codebook indicator may be included in the PMI or CSI. In some embodiments, the PMI or CSI may include a first portion of the PMI (or the CSI) and a second portion of the PMI (or the CSI). For example, the size of the second portion of the PMI (or the CSI) may be based on the first portion of the PMI (or the CSI). In some embodiments, the PMI (or the CSI) may include a first portion of the PMI (or the CSI), a second portion of the PMI (or the CSI), and a third portion of the PMI (or the CSI). For example, the size of the second portion of the PMI (or the CSI) may be based on the first portion of the PMI (or the CSI). As another example, the size of the third portion of the PMI (or the CSI) may be based on at least one of the first portion of the PMI (or the CSI) and the second portion of the PMI (or the CSI).

[0283] In some embodiments, the length of one first vector may be based on the number of antenna ports within one antenna port group or for one CSI-RS resource. In some embodiments, the length of one first vector may be the result of dividing the number of a plurality of antenna ports within one antenna port group or for one CSI-RS resource by 2. In some embodiments, the length of one first vector is

Number

Number

[0284] In some embodiments, the number of indicators (or fields) for the strongest coefficient may be based on the number of layers, and each one indicator (or field) for the strongest coefficient may correspond to a layer having an index.

[0285] In some embodiments, the indicator (or field) for the strongest coefficient corresponding to a layer having an index, or the bit size (or bit width) of the indicator (or field) for the strongest coefficient corresponding to a layer having an index, may be based on at least one of a value of 2, the first number of non-zero coefficients corresponding to one layer having an index, and the number of the plurality of first vectors.

[0286] In some embodiments, the bit size of the indicator (or field) for the strongest coefficient corresponding to a layer having an index may be based on at least one of the first number of non-zero coefficients corresponding to one layer having an index and 2×the number of the plurality of first vectors.

[0287] In some embodiments, the indicator (or field) for the strongest coefficient corresponding to a layer having an index may be included in the PMI (or the CSI), or a first portion of the PMI (or the CSI), or a second portion of the PMI (or the CSI).

[0288] In some embodiments,

Number

Number

[0289] In some embodiments, the one or more indicators (or one or more bitmaps) for indicating non-zero coefficients may indicate an index of a second amplitude coefficient and / or an index of a phase coefficient. In some embodiments, each bit or code point of the indicator (or bitmap) may correspond to a layer with an index, correspond to a first vector (or first beam) with an index, correspond to a second vector with an index, and indicate whether a second amplitude coefficient and / or a phase coefficient corresponding to a third vector with an index has been reported (or whether the value is zero). In some embodiments, the value of each bit is either 0 or 1. For example, 0 may indicate that a second amplitude coefficient and / or a phase coefficient corresponding to a layer with an index, corresponding to the first vector (or first beam) with the index, corresponding to the second vector with the index, and corresponding to the third vector with the index has not been reported (or the value is zero). For example, 1 may indicate that a second amplitude coefficient and / or a phase coefficient corresponding to a layer with an index, corresponding to the first vector (or first beam) with the index, corresponding to the second vector with the index, and corresponding to the third vector with the index has been reported (or the value is not zero).

[0290] In some embodiments, the number of the one or more indicators (or one or more bitmaps) for indicating non-zero coefficients may be the same as the number of layers. For example, each one of the indicators (or one bitmap) for indicating non-zero coefficients may correspond to one layer with an index.

[0291] In some embodiments, the size of the indicator (or bitmap) for indicating a non-zero coefficient corresponding to a layer with an index may be based on the number of a plurality of second vectors corresponding to the layer with the index, the number of a plurality of first vectors, and the number of a plurality of third vectors corresponding to the layer with the index.

[0292] In some embodiments, the number of the plurality of second vectors may be determined based on at least one of the number of layers, the size of one first sub-band, the first parameter for the codebook and the size of the one second sub-band, the third parameter for the codebook, and the second parameter for the codebook.

[0293] In some embodiments, the number of one or more indicators (or one or more bitmaps) for indicating non-zero coefficients may be based on the number of layers. In some embodiments, each of the one or more indicators (or one or more bitmaps) for indicating non-zero coefficients may correspond to a layer having an index.

[0294] In some embodiments, the number of one or more indicators (or one or more fields) for a plurality of second amplitude coefficients corresponding to a layer having an index may be based on at least one of the first number of non-zero coefficients and the number of values (or bits or code points) having the value "1" in the indicator (or bitmap) for indicating the non-zero coefficients corresponding to the layer having the index or the number of 1s.

[0295] In some embodiments, the number of one or more indicators (or one or more fields) for a plurality of phase coefficients corresponding to a layer having an index may be based on at least one of the first number of non-zero coefficients and the number of values (or bits or code points) having the value "1" in the indicator (or bitmap) for indicating the non-zero coefficients corresponding to the layer having the index or the number of 1s.

[0296] In some embodiments, the number of the plurality of second vectors

Number

[0297] In some embodiments, the size or length of one second vector may be determined based on at least one of the number of PRBs for the BWP, the number of layers, the size of one first sub-band, the number of a plurality of first sub-bands, a first parameter for the codebook, the size of one second sub-band, the number of a plurality of second sub-bands, and a second parameter for the codebook. In some embodiments, the size or length of one second vector

Number

[0298] In some embodiments, the number of a plurality of third vectors

Number

[0299] In some embodiments, the number of a plurality of third vectors

Number

Number

[0300] In some embodiments, the number of a plurality of fourth vectors

Number

Number

Number

[0301] In some embodiments, the size or length of one third vector may be determined based on at least one of the number of time units, the number of layers, the size of one time unit, the number of slots / sub-slots / symbols for one time unit, the time interval between two time units, the fourth parameter for the codebook, the fifth parameter for the codebook, and the sixth parameter for the codebook. In some embodiments, the size or length of one third vector is

Number

[0302] In some embodiments, the fourth parameter for the codebook

Number

[0303] In some embodiments, the size or length of one third vector may be a positive integer. For example,

Number

[0304] In some embodiments, the terminal device may receive at least one CSI-RS, and the number of antenna ports for the CSI-RS may be determined based on at least one parameter for the antenna port setting.

[0305] In some embodiments, the first vector may be a vector in the spatial domain. In some embodiments, the first vector

Number

[0306] In some embodiments,

Number

Number

Number

Number

[0307] In some embodiments, the length of one first vector may be based on the result of dividing the number of the plurality of antenna ports in one CSI-RS resource by 2.

[0308] In some embodiments, the length of one second vector may be determined based on a first parameter for the codebook and the number of first subbands. In some embodiments, the number of a plurality of second vectors may be determined based on a third parameter for the codebook, the number of second subbands, and the first parameter for the codebook. In some embodiments, the number of second subbands may be based on the first parameter for the codebook and the number of first subbands. In some embodiments, the second size of one second subband may be determined based on the first parameter for the codebook and the first size of one first subband.

[0309] Figures 12A and 12B show schematic diagrams of a spatial domain, a frequency domain, and a Doppler / time domain basis according to a conventional method. To enhance precoding for a UE moving at a fairly high speed, it has been proposed to introduce a Doppler / time domain basis into a plurality of codebooks or a plurality of precoding matrices, e.g., a plurality of type II codebooks. As shown in FIGS. 12A and 12B, in the spatial domain, a first matrix W1 (e.g., composed of a spatial domain basis or a plurality of first vectors) has a dimension of P*2L, where P indicates the number of antenna ports for a CSI-RS resource or an antenna port group, and L indicates the number of beams or first vectors (e.g., within each polarization group consisting of two polarization directions). In the frequency domain, a third matrix W f H has a dimension of Mv*N3, where N3 indicates the number of frequency units or the number of second subbands. For example, N3 may be understood as the number of subbands in the frequency domain. Mv is the number of frequency basis vectors or second vectors. In the Doppler / time domain, a fourth matrix W d H has a dimension of Md*N4, where N4 indicates the number of Doppler / time units, and Md is the number of Doppler / time basis vectors or the number of third vectors.

[0310] As shown in FIG. 12A, in a plurality of codebooks or precoding matrices including spatial domain, frequency domain, and Doppler / time domain vectors,

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

[0311] As shown in FIG. 12B, in a plurality of codebooks or precoding matrices including spatial domain, frequency domain, and Doppler / time domain vectors,

Number

Number

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Number

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Number

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Number

[0312] In some embodiments,

Number

Number

Number

Number

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Number

Number

Number

Number

Number

Number

Number

Number

Number

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Number

[0313] In some embodiments, [Number] is the index [Number] corresponds to the layer having [Number] corresponding to a first vector having, index

Number

Number

[0314] In some embodiments,

Number

Number

Number

[0315] In some embodiments, index

Number

Number

Number

Number

Number

[0316] In some embodiments,

Number

[0317] In some embodiments,

Number

[0318] In some embodiments,

Number

[0319] In some embodiments,

Number

Number

[0320] In some embodiments, one first vector

Number

Number

[0321] In some embodiments,

Number

Number

Number

Number

Number

Number

Number

Number

[0322] In some embodiments,

Number

[0323] In some embodiments,

Number

Number

Number

Number

Number

Number

Number

[0324] In some embodiments,

Number

Number

Number

Number

Number

Number

Number

[0325] In some embodiments, it corresponds to a layer having an index r and the second matrix is, [Number] or [Number] may also be. [Number]

[0326] In some embodiments, [Number] and [Number] (for example, [Number] the same as) is the first amplitude coefficient corresponding to the layer with index [Number] It may also be. In some embodiments, [Number] corresponds to the layer with index [Number] and corresponds to one first vector with index [Number] and corresponds to a third vector with index [Number] and corresponds to the layer with index [Number] It may also be a second amplitude coefficient corresponding to a third vector having [Number] (For example, [Number] being the same as) corresponds to a layer having index [Number] and corresponds to a first vector having index [Number] and corresponds to a third vector having index [Number] and may be a phase coefficient corresponding to a third vector having index [Number] .

[0327] In some embodiments, for a codebook or precoding matrix or precoder corresponding to a layer having index r, a second sub - band having index z, and a time unit having index T, [Number] is.

[0328] In some embodiments, [Number] may be a variant for power calculation or power normalization.

[0329] In some embodiments,

Number

Number

[0330] In some embodiments,

Number

[0331] In some embodiments, for the bits or code points or values of the one or more indicators (or one or more bitmaps) indicating non-zero coefficients having a value of 0, the second amplitude coefficients and / or phase coefficients corresponding to these bits or code points or values may be set to 0.

[0332] In some embodiments, the index

Number

Number

Number

Number

Number

[0333] In some embodiments,

Number

[0334] In some embodiments,

Number

[0335] In some embodiments,

Number

[0336] In some embodiments,

Number

Number

[0337] In some embodiments, the value of one first amplitude coefficient is

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

[0338] In some embodiments, the value of one first amplitude coefficient is

Number

Number

Number

Number

Number

Number

Number

[0339] In some embodiments, for a first antenna port group (e.g., index

Number

Number

Number

[0340] In some embodiments, the value of the first amplitude coefficient corresponding to an antenna port group not included in the second plurality of antenna port groups may be 0. In some embodiments, the indicator or field value for the first amplitude coefficient corresponding to an antenna port group not included in the second plurality of antenna port groups may be 0. In some embodiments, the first amplitude coefficient corresponding to an antenna port group not included in the second plurality of antenna port groups, or the indicator or field value for the first amplitude coefficient, may not be reported within the PMI.

[0341] In some embodiments, the value of one second amplitude coefficient is

Number

Number

Number

Number

Number

Number

Number

[0342] In some embodiments, the value of one second amplitude coefficient is

Number

Number

Number

Number

Number

Number

[0343] In some embodiments, the value of one second amplitude coefficient is [Number] It may be at least one of. In some embodiments, the bit size for one second amplitude coefficient may be 3 bits. In some embodiments, the value of an indicator or field for one second amplitude coefficient may be at least one of {0, 1, 2, 3, 4, 5, 6, 7}. In some embodiments, an indicator or field for one second amplitude coefficient having a value of 0 is the value [Number] It may also correspond to a second amplitude coefficient having. In some embodiments, an indicator or field for one second amplitude coefficient having a value of 1 is the value [Number] It may also correspond to a second amplitude coefficient having. In some embodiments, an indicator or field for one second amplitude coefficient having a value of 2 is the value [Number] It may also correspond to a second amplitude coefficient having. In some embodiments, an indicator or field for one second amplitude coefficient having a value of 3 is the value [Number] ​It may correspond to a second amplitude coefficient having. In some embodiments, an indicator or field for one second amplitude coefficient having a value of 4 is the value

Number

Number

Number

Number

[0344] In some embodiments, the value of one second amplitude coefficient may be at least one of {

Number

Number

[0345] In some embodiments, the value of the second amplitude coefficient corresponding to an antenna port group not included in the second plurality of antenna port groups may be 0. In some embodiments, the value of the indicator or field for the second amplitude coefficient corresponding to an antenna port group not included in the second plurality of antenna port groups may be 0. In some embodiments, the second amplitude coefficient corresponding to an antenna port group not included in the second plurality of antenna port groups, or the value of the indicator or field for the second amplitude coefficient, may not be reported within the PMI.

[0346] In some embodiments, for one or more indicators (or one or more bitmaps) indicating a non-zero coefficient having a value of 0, the value of the first amplitude coefficient corresponding to these bits or code points or values may be set to 0, and / or the value of the indicator or field for the first amplitude coefficient corresponding to these bits or code points or values may be set to 0. In some embodiments, the value of the first amplitude coefficient corresponding to these bits or code points or values, and / or the value of the indicator or field for the first amplitude coefficient corresponding to these bits or code points or values, may not be reported within the PMI.

[0347] In some embodiments, for the bits or code points or values of one or more indicators (or one or more bitmaps) indicating non-zero coefficients having a value of 0, the value of the second amplitude coefficient corresponding to these bits or code points or values may be set to 0, and / or the value of the indicator or field for the second amplitude coefficient corresponding to these bits or code points or values may be set to 0. In some embodiments, the value of the second amplitude coefficient corresponding to these bits or code points or values, and / or the value of the indicator or field for the second amplitude coefficient corresponding to these bits or code points or values may not be reported within the PMI.

[0348] In some embodiments, for the bits or code points or values of one or more indicators (or one or more bitmaps) indicating non-zero coefficients having a value of 0, at least one value of the phase coefficients corresponding to these bits or code points or values may be set to 0, and / or the value of the indicator or field for at least one of the phase coefficients corresponding to these bits or code points or values may be set to 0. In some embodiments, at least one value of the phase coefficients corresponding to these bits or code points or values, and / or the value of the indicator or field for at least one of the phase coefficients corresponding to these bits or code points or values may not be reported within the PMI.

[0349] In some embodiments, the value of one phase coefficient is

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

[0350] In some embodiments,

Number

[0351] Next, reference is made to FIG. 13, which shows a signaling diagram illustrating a communication process 1300 according to some embodiments of the present disclosure.

[0352] In some embodiments of the present disclosure, the terminal device 110 determines (1310) whether to apply Doppler / time domain compression or a Doppler / time domain basis type in order to report a precoding matrix indicator (PMI) to the network device 120. In one example, the terminal device 110 may determine whether to apply Doppler / time domain compression to notify the network device 120 of the PMI. In another example, the terminal device 110 may determine a Doppler / time domain basis type for notifying the network device 120 of the PMI.

[0353] In some embodiments, a time unit may include a plurality of slots or sub - slots or symbols. For example, the number of a plurality of slots or sub - slots or symbols within a time unit may be

Number

Number

Number

Number

[0354] In some embodiments, the time interval between two time units may be a plurality of slots or sub - slots or symbols. For example, the number of a plurality of slots or sub - slots or symbols for the time interval may be

Number

Number

Number

Number

[0355] In some embodiments, the number of slots / sub-slots / symbols within a time unit and / or the time interval between two time units may be fixed or predetermined. In some embodiments, the number of slots / sub-slots within a time unit and / or the time interval between two time units may be set by the network device 120. In some embodiments,

Number

Number

[0356] In some embodiments, the terminal device 110 may determine the length of the time unit associated with the Doppler / time domain (e.g.,

Number

Number

[0357] In some embodiments, the Doppler / time domain basis type may include a first type and a second type. In some embodiments, the first type may indicate that Doppler / time domain compression has been applied. In some embodiments, the second type may indicate that Doppler / time domain compression has not been applied. In some embodiments, the first type may represent a third vector, and the Doppler / time domain vector may be a DFT, or a DCT, or an oversampled DFT, or a Slepain vector. In some embodiments, the second type may represent a third vector, or the Doppler / time domain vector may be a vector having only one element with a value of 1 and other elements with a value of 0, or an identity vector.

[0358] In some embodiments, if Doppler / time domain compression is applied, or if the Doppler / time domain basis type is the first type, the terminal device 110 may accordingly determine the rank indicator (RI) to be 1 or 2. In other words, if RI > 2, the number of Doppler / time domain bases may be 1, or there may be no report of the Doppler / time domain bases, or there may be no Doppler / time domain compression, or the Doppler / time domain basis type is the second type. Alternatively or additionally, such determination may be made by the network device 120. In other words, if Doppler / time domain compression is applied, or if the Doppler / time domain basis type is the first type, the network device 120 may accordingly determine the rank indicator (RI) to be 1 or 2.

[0359] Next, refer to FIG. 13 again. In some embodiments, the terminal device 110 transmits an instruction 1324 to the network device 120 (1320). The instruction 1324 indicates whether to apply Doppler / time domain compression or a Doppler / time domain base type. For example, the terminal device 110 may transmit an instruction 1324 to the network device 120 indicating whether to apply Doppler / time domain compression. As another example, the terminal device 110 may transmit an instruction 1324 of the Doppler / time domain base type to the network device 120. In some embodiments, such an instruction 1324 may be included in a CSI report reported to the network device 120. FIG. 14A shows a schematic bitmap of parameter settings according to some embodiments of the present disclosure. In this schematic bitmap, first, Md is arranged, and then Mv is arranged. The size of the bitmap may be 2L * Md * Mv for one layer with index r. For specific Md and Mv values, each bit in the bitmap is mapped to a specific Doppler-frequency domain coefficient. An indication of non-zero coefficients in bitmap form may be reported by the terminal device 110 to the network device 120. For example, the terminal device 110 may include a first indication field indicating non-zero coefficients in the CSI and report the CSI to the network device 120.

[0360] FIG. 14B shows another schematic bitmap of parameter settings according to some embodiments of the present disclosure. In this schematic bitmap, different from the bitmap shown in FIG. 14A, first, Mv is arranged, and then Md is arranged. For specific Md and Mv values, each bit in the bitmap is mapped to a specific frequency-Doppler domain coefficient.

[0361] In one example, the Doppler / time domain base or the length N4 of one third vector may be set by the network device 120 or reported by the terminal device 110. For example, the terminal device 110 may include the length N4 in CSI part 1 and report the CSI to the network device 120. As another example, the terminal device 110 may receive the length N4 from the network device 120.

[0362] In another example, the number Md of the third vectors may be set by the network device 120 or reported by the terminal device 110. For example, the terminal device 110 may include the number Md in CSI part 1 and report the CSI to the network device 120. As another example, the terminal device 110 may receive the number Md from the network device 120.

[0363] In another example, the length of the time unit (e.g., the number of slots) may be set by the network device 120 or reported by the terminal device. For example, the terminal device 110 may include the length of the time unit in CSI part 1 and report the CSI to the network device 120. As another example, the terminal device 110 may receive the length of the time unit from the network device 120.

[0364] In some embodiments, the terminal device 110 may report to the network device 120 the number of Doppler / time domain base vectors, the length of the Doppler / time domain base vectors, the length of the time unit associated with the Doppler / time domain, the bitmap of non-zero coefficients in the second matrix associated with the coefficients for the codebook, or any combination of the above. Alternatively or additionally, the terminal device 110 may receive from the network device 120 the number of Doppler / time domain base vectors, the length of the Doppler / time domain base vectors, the length of the time unit associated with the Doppler / time domain, or any combination of the above, set by the network device 120.

[0365] On the other side of the communication, the terminal device 110 may receive from the terminal device 110 the number of Doppler / time domain basis vectors, the length of the Doppler / time domain basis vectors, the length of the time unit associated with the Doppler / time domain, the bitmap of non-zero coefficients in the second matrix associated with the coefficients for the codebook, or any combination of the above. Alternatively, the terminal device 110 may transmit to the terminal device 110 the number of Doppler / time domain basis vectors, the length of the Doppler / time domain basis vectors, the length of the time unit associated with the Doppler / time domain, or any combination of the above, which are set by the network device 120.

[0366] In one example, the length N4 of the Doppler / time domain basis may be set by the network device 120 or reported by the terminal device 110. For example, the terminal device 110 may include the length N4 in CSI part 1 and report the CSI to the network device 120. As another example, the terminal device 110 may receive the length N4 from the network device 120.

[0367] In another example, the number Md of bases may be set by the network device 120 or reported by the terminal device 110. For example, the terminal device 110 may include the number Md in CSI part 1 and report the CSI to the network device 120. As another example, the terminal device 110 may receive the number Md from the network device 120.

[0368] In another example, the length of the time unit (e.g., the number of slots) may be set by the network device 120 or reported by the terminal device 110. For example, the terminal device 110 may include the length of the time unit in CSI part 1 and report the CSI to the network device 120. As another example, the terminal device 110 may receive the length of the time unit from the network device 120.

[0369] Referring again to FIG. 13, on the other side of the communication, the network device 120 receives an instruction 1324 from the terminal device 110 as to whether to apply Doppler / time domain compression or the Doppler / time domain base type (1330). For example, the instruction 1324 as to whether to apply Doppler / time domain compression or the Doppler / time domain base type may be reported from the terminal device 110 in the form of a CSI report, and the network device 120 can know how the terminal device 110 proposes regarding whether to apply Doppler / time domain compression or the Doppler / time domain base type by receiving such a CSI report and obtaining this instruction.

[0370] After receiving the instruction 1324 from the terminal device 110 (1330), the network device 120 processes the PMI reported by the terminal device 110 based on the instruction 1324 (1340). For example, when the instruction 1324 indicates to apply Doppler / time domain compression or the Doppler / time domain base type, the network device 120 may apply Doppler / time domain compression or the Doppler / time domain base type to process the reported PMI. As another example, when the instruction 1324 indicates not to apply Doppler / time domain compression or the Doppler / time domain base type, the network device 120 may process the reported PMI without applying Doppler / time domain compression or the Doppler / time domain base type.

[0371] In this way, it becomes more flexible to switch between high / medium mobility and low mobility. For example, during a business trip on a high-speed railway, Doppler / time domain compression or the Doppler / time domain base type may be provided to the businessman. When getting off the high-speed railway and walking on the road, this businessman may not be provided with Doppler / time domain compression or the Doppler / time domain base type as in the past. Therefore, the communication performance for high / medium mobility terminal devices can be improved without increasing the overhead for low mobility terminal devices.

[0372] FIG. 15A is a schematic diagram with Doppler / time compression according to some embodiments of the present disclosure. As shown in FIG. 15A, a plurality of Doppler / time domain basis vectors are selected from a set of Doppler / time domain basis vectors shown as W(0), W(1), W(2), W(3), … W(N4-1), where N4 represents the number of Doppler / time units. Due to the compression effect, the number of selected Doppler / time domain basis vectors should be smaller than N4.

[0373] For comparison, FIG. 15B shows a schematic diagram without Doppler / time compression according to some embodiments of the present disclosure. In this case, it may be the same as a plurality of W2 reported for different time unit indices. Specifically, when there is no Doppler shift, as shown in FIG. 15C, a conventional codebook is used.

[0374] As shown in FIGS. 15A, 15B, and 15C, according to the present disclosure, the switching between high / medium mobility and low mobility becomes more flexible. Therefore, the communication performance for high / medium mobility terminal devices can be improved without increasing the overhead for low mobility terminal devices.

[0375] In some embodiments, an indication 1324 to apply Doppler / time domain compression or Doppler / time domain basis type indicates a plurality of Doppler / time domain basis vectors selected from a set of Doppler / time domain basis vectors.

[0376] For example, there may be at least one codebook indication field indicating the index of the Doppler / time domain basis that implies that Doppler / time domain compression (e.g., DFT basis) is employed. Alternatively, as another example, at least one codebook indication field may not indicate any Doppler / time domain basis, which implies that a conventional codebook or W1, Wf, and a plurality of W2 (i.e., a plurality of codebooks on different time units) are employed.

[0377] In some embodiments, the indication 1324 not to apply Doppler / time domain compression or Doppler / time domain base type is associated with the Doppler / time domain, but indicates a plurality of codebooks or a plurality of PMIs or a plurality of second matrices for different indices of time units without Doppler / time domain compression. Each of the plurality of second matrices may be associated with coefficients for a codebook. For example, the second matrix may be referred to as M2.

[0378] In some embodiments, the terminal device 110 may determine whether to apply Doppler / time domain compression or Doppler / time domain base type as follows. If the terminal device 110 determines that the speed of the terminal device 110 is greater than or equal to a pre-defined threshold speed or the correlation between at least two CSI-RS resources is less than or equal to a pre-defined threshold, the terminal device 110 may determine to apply Doppler / time domain compression or Doppler / time domain base type. Alternatively, if the terminal device 110 determines that the speed of the terminal device is less than or equal to a pre-defined threshold speed or the correlation between at least two CSI-RS resources is greater than or equal to a pre-defined threshold, the terminal device 110 may determine not to apply Doppler / time domain compression or Doppler / time domain base type.

[0379] In one example, the terminal device 110 may determine its speed by calculating distance and time. Then, the terminal device 110 may determine whether its speed is greater than or equal to a pre-defined threshold Th1. If the determined (calculated) speed is greater than or equal to the pre-defined threshold Th1, the terminal device 110 may determine to apply Doppler / time domain compression or Doppler / time domain base type. Conversely, if the determined (calculated) speed is lower than the pre-defined threshold Th1, the terminal device 110 may determine not to apply Doppler / time domain compression or Doppler / time domain base type.

[0380] In another example, the terminal device 110 may determine whether the correlation between at least two CSI-RS resources is less than or equal to a predefined threshold Th2. If so, the terminal device 110 may determine to apply Doppler / time domain compression or a Doppler / time domain basis type. Otherwise, the terminal device 110 may determine not to apply Doppler / time domain compression or a Doppler / time domain basis type.

[0381] In some embodiments, a first matrix associated with the Doppler / time domain and indicated within at least one codebook information field in the PMI includes a plurality of Doppler / time domain basis vectors.

[0382] For W(t), the index of t(md) for non-zero W(t) is controllable by Wd. The selection of t for non-zero W(t), or the selection of the time unit index for non-zero W(t), may be based on the same indication field for the selection of the Doppler / time basis.

[0383] The fourth matrix or the plurality of third vectors or the Doppler / time basis is

Number

[0384] For example, when Wd is composed of a Doppler / time basis (in other words, in the case of Doppler / time domain compression), the indication field indicates the index of the Doppler / time basis. As another example, when Wd is a replacement matrix (meaning no Doppler / time domain compression), the indication field indicates the index of the column having a non-zero vector (in each vector, only one element is 1 and the other elements are 0). This is shown in FIG. 16.

[0385] FIG. 16 shows a schematic diagram without Doppler / time compression according to some embodiments of the present disclosure. As shown in FIG. 16, all elements in the first column are 0, and the vector for column t(md) in Wd may be such that the (md + 1)-th element is 1 and the others are 0. In some embodiments, the first matrix associated with the Doppler / time domain and indicated within at least one codebook information field in the PMI is a permutation matrix.

[0386] In some embodiments, the terminal device 110 may select an index of a time unit based on an instruction field for selecting a Doppler / time domain basis vector from a set of Doppler / time domain basis vectors. The instruction field is designed within the CSI, and the terminal device 110 may transmit a CSI report to the network device 120. For example, the matrix Wd in FIG. 15B may be

Number

[0387] On the other side of the communication, the terminal device 110 may receive a CSI report and determine an index of a time unit based on the instruction field in the CSI. The instruction field is used to select a Doppler / time domain basis vector from a set of Doppler / time domain basis vectors as described above.

[0388] For W(t), the index of t for non-zero W(t) is controllable by Wd. For example, the selection of t for non-zero W(t), or the selection of the time unit index for non-zero W(t), may be based on the same indication field (e.g., the second indication field) for the selection of the Doppler / time basis. As another example, in the matrix Wd, the elements corresponding to t = 0, 2, 4, … 2n may all be zero, and the vector for column t(md) may be set such that the (md + 1)-th element is 1 and the others are 0.

[0389] FIG. 17 shows a schematic diagram without Doppler / time according to some embodiments of the present disclosure. In some embodiments, when there is no Doppler (meaning no Doppler shift), based on the new codebook structure introduced in the present disclosure, an indication not to apply Doppler / time domain compression or Doppler / time domain basis type indicates a codebook that does not have a first matrix associated with the Doppler / time domain or does not have at least one codebook information field in the PMI.

[0390] In one example, only one Doppler / time basis may be selected (in other words, Md = 1), and the value of Md may be reported by the terminal device 110 to the network device 120. In such a case, the network device 120 can know from the received report that the terminal device 110 is proposing not to apply Doppler / time domain compression or Doppler / time domain basis type, which indicates a codebook that does not have a first matrix (e.g., the matrix Wd as described above) associated with the Doppler / time domain. This scenario is shown in FIG. 15C for illustration purposes. As shown in FIG. 15C, only one Doppler / time unit may be selected. In such a case, as described above, a conventional codebook may be used.

[0391] In another example, only one column of coefficients corresponding to the Doppler / time-based is non-zero. In such a case, the network device 120 can know from the received report that the terminal device 110 proposes not to apply Doppler / time domain compression or Doppler / time domain base type, which indicates a codebook that does not have at least one codebook information field in the PMI. As shown in FIG. 18C, for the Doppler / time-based W 2, mv only one column of coefficients corresponding to it is non-zero. More specifically, only the first column of coefficients corresponding to the Doppler / time-based W 2, mv is non-zero. This indicates that there is no Doppler / time domain. The network device 120 can know from the received report that the terminal device 110 proposes not to apply Doppler / time domain compression or Doppler / time domain base type.

[0392] In some embodiments, the codebook may be indicated by indicating one of a set of Doppler / time domain base vectors. Alternatively, in some embodiments, the codebook is indicated by setting one column of a second matrix associated with the coefficients for the codebook to non-zero and setting all elements in the other columns of the second matrix to zero. As described above, in the example shown in FIG. 18C, only the first column of coefficients corresponding to the Doppler / time base W 2, mv is non-zero. As shown in FIG. 18, by indicating this one Doppler / time domain base vector within a set of Doppler / time domain base vectors, the network device 120 can know from the received report that the terminal device 110 proposes to use a codebook corresponding to one Doppler / time domain base vector for future communication.

[0393] FIG. 18A shows a schematic diagram without Doppler / time compression according to some embodiments of the present disclosure. A bitmap having a size of 2L×Md×Mv is shown in FIG. 18A. As mentioned in the description of FIGS. 12A and 12B above, 2L represents the number of spatial domain basis vectors, Md represents the number of Doppler / time domain basis vectors, and Mv represents the number of frequency domain basis vectors. The columns indicated by (md = 0, mv = 0) and (md = 0, mv = 1) in the bitmap all have zero values.

[0394] FIG. 18B shows another schematic diagram without Doppler / time compression according to some embodiments of the present disclosure. The columns indicated by (md = 0, mv = 0), (md = 0, mv = 1),..., and (md = 0, mv = Mv) in the bitmap all have zero values. FIG. 18C shows another schematic diagram without Doppler / time compression according to some embodiments of the present disclosure. As shown in FIG. 18C, the first column in the matrix W 2, mv all has zero values.

[0395] In some embodiments, the non-zero columns are represented by a bitmap having a size of 2L×Md×Mv, where 2L represents the number of spatial domain basis vectors, Md represents the number of Doppler / time domain basis vectors, and Mv represents the number of frequency domain basis vectors. For example, in the examples shown in FIGS. 18A and 18B, the zero-value columns and the non-zero columns are represented by a bitmap having a size of 2L×Md×Mv as described above. The positions of the non-zero columns shown in the bitmap may be arbitrary. The positions of the non-zero columns shown in FIGS. 18A, 18B, and 18C are for illustrative purposes only, and the present disclosure is not limited to such examples in this regard.

[0396] As another example, when a bitmap indicating non-zero coefficients shows that at least one column (for example, the number of columns may be Mz (1 ≦ Mz ≦ Md)) of the coefficients for W2,md (corresponding to each Doppler / time basis and having the same column index for all zero elements in each of W2,md) is 0, Wd may be a permutation matrix and there may be no Doppler / time compression. In such a case, the Md - Mz W2 matrices may be actually reported by the terminal device 110 to the network device 120, and the index of the time unit corresponding to each W2 may be based on the second indication field.

[0397] In some embodiments, the terminal device 110 may arrange the column of the strongest coefficients after the first column having all zero coefficients in the second matrix. For example, when Wd is a permutation matrix (in other words, Doppler / time compression is not employed), the index of the column corresponding to the strongest coefficient may be further indicated by the terminal device 110 to the network device 120. The strongest coefficient cannot be rotated to the first column. When there is no Doppler / time compression based on at least one column of all zero values, the index of the column corresponding to the strongest coefficient may be the first column having all non-zero values after the first column having all zero value coefficients. This scenario may be represented by the following formula (3).

Number

Number

Number

Number

Number

[0398] Note that the first column having all zero value coefficients is not necessarily the first column within W 2, mv and may be in any position. In another example, the first column having all zero value coefficients may not be the first column within W 2, mv . The following equation (4) shows such a scenario.

Number

Number

Number

Number

Number

[0399] In some embodiments, the terminal device 110 can rotate the column containing the strongest coefficient of the second matrix associated with the coefficients of the codebook so that it becomes the first column of the second matrix. For example, in the case of Wd composed at least based on DFT, and when there is a common Doppler / time domain basis for the spatial domain and the frequency domain, the strongest coefficient for layer r can be rotated to the first column. The rotation may be performed using a rotation matrix R defined as follows.

Number

Number

Number

Number

Number

Number

[0400] In some embodiments, the terminal device 110 may determine the bit size of the indication field of the strongest coefficient based on 2L representing the number of spatial region basis vectors, and determine the bit size of the indication field of the Doppler / time region basis vectors based on Ns-1 and Md-1. Md represents the number of Doppler / time region basis vectors, and Ns represents one of the length of the Doppler / time region basis vectors, the number of oversampled Doppler / time region basis vectors, and the number of Doppler / time region basis vectors within a window selected from the Doppler / time region basis vectors or the oversampled Doppler / time region basis vectors.

[0401] For example, as described above, in the case of Wd configured at least based on DFT, and when there is a common Doppler / time region basis for the spatial region and the frequency region, the strongest coefficient for layer r can be rotated to the first column.

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

Number

[0402] Furthermore,

Number

Number

Number

Number

Number

Number

Number

[0403] FIG. 19 shows a schematic diagram of a CSI structure according to some embodiments of the present disclosure. As shown in FIG. 19, there are a CSI part 1 and a CSI part 2. The CSI part 1 has a fourth instruction field. The fourth instruction field includes an instruction 1 and an instruction 2. The instruction 1 indicates that the fifth instruction field exists in the CSI part 2, and the instruction 2 indicates that the fifth instruction field does not exist in the CSI part 2. The CSI part 2 further includes a third instruction field that constitutes a first set of information fields. These instruction fields indicate whether the fifth instruction field exists or whether it does not constitute a set of second information fields.

[0404] In some embodiments, the Doppler / time basis selection may be reported by the terminal device 110 to the network device 120. For example, the terminal device 110 may transmit the Doppler / time basis selection to the network device 120 via a second indication field within the CSI report. The size of the second indication field may be ceil(log2( C(Ns, Md))) or ceil(log2(Ns-1,Md-1)) (e.g., there is rotation and one basis is rotated such that it is [1,1,…1]). Ns may be at least one of N4 (e.g., in the case of an orthogonal DFT basis for Doppler / time basis), N4*O3 (e.g., an oversampled DFT basis for Doppler / time basis), N5 (e.g., a window selected from N4 or N4*O3 similar to the case where N3>19 for frequency domain compression, e.g., N5 = A*Md, where A may be 2 or 3 or 4).

Number

[0405] In one example, in the absence of Doppler / time compression (or basis type) indicated / reported by a fourth indication field (e.g., within CSI part 1) by the terminal device 110, in the first set of information fields of CSI part 2, there may be a third indication field indicating the SCI for the layer with index r, and the bit size of the third indication field may be ceil(log2(2L)).

[0406] Also, in this example, when the fourth indication field indicates Doppler / time compression (e.g., DFT basis type), the third indication field in the first set of information fields of CSI part 2 indicates the index of the strongest coefficient, which is the same as the conventional method, and rotation may be applied.

[0407] Also, in this example, when the fourth indication field indicates no Doppler / time compression, there may be a fifth indication field in the first or second set of information fields of CSI part 2 to indicate the index of the column corresponding to the strongest coefficient, and the bit size of the fifth indication field may be ceil(log2(Md)). In this way, the third indication field and the fifth indication field jointly indicate the index of the strongest coefficient, where the fifth indication field indicates which column of the matrix Wd has the strongest coefficient, and the third indication field further indicates which element in the column indicated by the fifth indication field has the strongest coefficient.

[0408] In some embodiments, when Doppler / time domain compression or Doppler / time domain basis type is applied, the indication field indicates the element index of the strongest coefficient of the second matrix within a predefined column of the second matrix, and the second matrix is associated with the coefficients for the codebook. For example, when the indication field in CSI part 1 indicates Doppler / time compression (e.g., DFT basis type), the indication field in the first set of information fields of CSI part 2 can indicate the index of the strongest coefficient (i.e., the conventional method). For example, in this case, rotation may be applied.

[0409] If the Doppler / time domain compression or Doppler / time domain base type is not applied, another indication field indicates the column index of the strongest coefficient in the second matrix, and the indication field for indicating the element index indicates the element index of the strongest coefficient in the column. For example, if the indication field in CSI part 1 indicates no Doppler / time compression, there may be another indication field in the first or second set of information fields in CSI part 2 to indicate the index of the column corresponding to the strongest coefficient, and the bit size may be ceil(log2(Wd)). In other words, the indication field for indicating the element index and the fifth indication field for indicating the column index together indicate the index of the strongest coefficient.

[0410] For example, as described above, if the Doppler / time domain compression or Doppler / time domain base type is not applied, the fifth indication field may indicate which column of the matrix Wd (associated with the coefficients for the codebook according to the present disclosure as described above) has the strongest coefficient, and the third indication field may further indicate which element in the column indicated by the fifth indication field has the strongest coefficient.

[0411] In some embodiments, the indication 1324 of whether to apply Doppler / time domain compression or Doppler / time domain base type is included in a first part of channel state information (CSI), and the indication field for the element index and the indication field for the column index are included in a second part of the CSI. For example, as shown in FIG. 19, the fourth indication field, i.e., the indication 1324 of whether to apply Doppler / time domain compression or Doppler / time domain base type, may be included in a first part of channel state information (CSI) denoted as "CSI part 1". The indication field for the element index (corresponding to the "third indication field" in FIG. 19) and the indication field for the column index (corresponding to the "fifth indication field" in FIG. 19) are included in a second part of the CSI denoted as "CSI part 2".

[0412] In some embodiments, when Doppler / time domain compression or Doppler / time domain base type is applied, the indication field of the first size indicates the element index of the strongest coefficient within a pre-defined column of a second matrix within the second matrix, where the second matrix is associated with coefficients for a codebook, and when Doppler / time domain compression or Doppler / time domain base type is not applied, the indication field of the second size indicates the column index and the element index within the column for the strongest coefficient within the second matrix.

[0413] For example, as shown in FIG. 19, the bit size of the third indication field for indicating the SCI for the layer with index r may depend on the indication of the fourth indication field within CSI part 1. In such a case, the fourth indication field may indicate whether there is Doppler / time compression (or the base type for Wd). Also, in this example, when the fourth indication field indicates Doppler / time compression (e.g., DFT base type), the bit size for the third field within the first set of information fields of CSI part 2 may be ceil(log2(2L)). In this case, rotation may be applied. Also, in this example, when the fourth indication field indicates that there is no Doppler / time compression, the bit size for the third indication field within the first set of information fields of CSI part 2 may be ceil(log2(2L*Wd)).

[0414] In some embodiments, the indication 1324 of whether to apply Doppler / time domain compression or Doppler / time domain base type is included in the first part of the channel state information (CSI), and the indication field for the indication of the strongest coefficient is included in the second part of the CSI.

[0415] As shown in FIG. 19, the fourth indication field indicates whether to apply Doppler / time domain compression or Doppler / time domain base type, and the fourth indication field is included in the first part of the channel state information (CSI) represented as "CSI part 1" in FIG. 19. The fifth indication field is used for the indication of the strongest coefficient, and the fifth indication field is included in the second part of the CSI shown as "CSI part 2" in FIG. 19.

[0416] In some embodiments, the terminal device 110 may determine the bit size for each of the plurality of phase coefficients in the second matrix based on the length of the third vector or the Doppler / time domain basis vector, and the second matrix is associated with the coefficients for a plurality of codebooks or precoder matrices. In some embodiments, if the value of N4 is less than or equal to a first value, the bit size of the phase coefficient may be 4 (e.g.,

Number

Number

Number

Number

Number

[0417] FIG. 20 is a flowchart of an exemplary method 2000 implemented in a terminal device according to some embodiments of the present disclosure.

[0418] In block 2010, the terminal device 110 determines whether to apply Doppler / time domain compression or a Doppler / time domain basis type to report a precoding matrix indicator (PMI) to the network device 120. In block 2020, the terminal device 110 transmits an indication of whether to apply Doppler / time domain compression or a Doppler / time domain basis type to the network device 120.

[0419] In some embodiments, the indication to apply Doppler / time domain compression or a Doppler / time domain basis type indicates a plurality of Doppler / time domain basis vectors selected from a set of Doppler / time domain basis vectors.

[0420] In some exemplary embodiments, a first matrix associated with the Doppler / time domain and indicated within at least one codebook information field in the PMI includes a plurality of Doppler / time domain basis vectors.

[0421] In some exemplary embodiments, an indication not to apply Doppler / time domain compression or Doppler / time domain basis type indicates, for different indices of time units associated with the Doppler / time domain but without Doppler / time domain compression, a plurality of codebooks or a plurality of PMIs or a plurality of second matrices, each of the plurality of second matrices being associated with coefficients for a codebook.

[0422] In some exemplary embodiments, method 2000 further includes selecting an index of a time unit based on an indication field for selecting a Doppler / time domain basis vector from a set of Doppler / time domain basis vectors.

[0423] In some exemplary embodiments, a first matrix associated with the Doppler / time domain and indicated within at least one codebook information field in the PMI is a replacement matrix.

[0424] In some exemplary embodiments, an indication not to apply Doppler / time domain compression or Doppler / time domain basis type indicates a codebook that does not have a first matrix associated with the Doppler / time domain or does not have at least one codebook information field within the PMI.

[0425] In some exemplary embodiments, a codebook is indicated by indicating one of a set of Doppler / time domain basis vectors as the Doppler / time domain basis vector.

[0426] In some exemplary embodiments, a codebook is indicated by indicating one column of a second matrix associated with coefficients for the codebook as non-zero and all elements within other columns of the second matrix as zero.

[0427] In some exemplary embodiments, the non-zero columns are represented by a bitmap having a size of 2L×Md×Mv, where 2L represents the number of spatial-domain basis vectors, Md represents the number of Doppler / time-domain basis vectors, and Mv represents the number of frequency-domain basis vectors.

[0428] In some exemplary embodiments, method 2000 further includes, in a second matrix, placing a column of the strongest coefficients after a first column having all-zero coefficients.

[0429] In some exemplary embodiments, method 2000 further includes rotating a column including the strongest coefficients of a second matrix associated with coefficients for a codebook to be the first column of the second matrix.

[0430] In some exemplary embodiments, method 2000 further includes determining a bit size of an indication field of the strongest coefficients based on 2L that represents the number of spatial-domain basis vectors, and determining a bit size of an indication field of the Doppler / time-domain basis vectors based on Ns−1 and Md−1, where Md represents the number of Doppler / time-domain basis vectors, and Ns represents one of the length of the Doppler / time-domain basis vectors, the number of oversampled Doppler / time-domain basis vectors, and the number of Doppler / time-domain basis vectors within a window selected from the Doppler / time-domain basis vectors or the oversampled Doppler / time-domain basis vectors.

[0431] In some exemplary embodiments, when Doppler / time domain compression or Doppler / time domain basis type is applied, the first indication field (e.g., the indication field for the element index) indicates the element index of the strongest coefficient in the predefined column of the second matrix, the second matrix is associated with the coefficients for the codebook, and when Doppler / time domain compression or Doppler / time domain basis type is not applied, the second indication field (e.g., the indication field for the column index) indicates the column index of the strongest coefficient in the second matrix, and the first indication field indicates the element index of the strongest coefficient within the column.

[0432] In some exemplary embodiments, the indication of whether to apply Doppler / time domain compression or Doppler / time domain basis type is included in the first part of the channel state information (CSI), and the first indication field and the second indication field are included in the second part of the CSI.

[0433] In some exemplary embodiments, when Doppler / time domain compression or Doppler / time domain basis type is applied, the indication field of the first size indicates the element index of the strongest coefficient in the predefined column of the second matrix, the second matrix is associated with the coefficients for the codebook, and when Doppler / time domain compression or Doppler / time domain basis type is not applied, the indication field of the second size indicates the column index and the element index within the column for the strongest coefficient in the second matrix.

[0434] In some exemplary embodiments, the indication of whether to apply Doppler / time domain compression or Doppler / time domain basis type is included in the first part of the channel state information (CSI), and the indication field for the indication of the strongest coefficient is included in the second part of the CSI.

[0435] In some exemplary embodiments, method 2000 further includes determining a bit size for each of a plurality of phase coefficients in a second matrix based on the length of a Doppler / time domain basis vector, where the second matrix is associated with coefficients for a codebook.

[0436] In some exemplary embodiments, method 2000 further includes reporting to a network device at least one of a number of Doppler / time domain basis vectors, a length of a Doppler / time domain basis vector, a length of a time unit associated with the Doppler / time domain, and a bitmap of non-zero coefficients in a second matrix associated with coefficients for a codebook, or receiving from the network device at least one of a number of Doppler / time domain basis vectors, a length of a Doppler / time domain basis vector, and a length of a time unit associated with the Doppler / time domain, where the number of Doppler / time domain basis vectors, the length of the Doppler / time domain basis vector, and the length of the time unit associated with the Doppler / time domain are set by the network device.

[0437] In some exemplary embodiments, method 2000 further includes determining a length of a time unit associated with the Doppler / time domain as a time interval between measurement channel state information (CSI)-reference signal (RS) resources.

[0438] In some exemplary embodiments, method 2000 further includes determining a rank indicator (RI) as 1 or 2 in response to applying Doppler / time domain compression or a Doppler / time domain basis type.

[0439] In some exemplary embodiments, determining whether to apply Doppler / time domain compression or a Doppler / time domain base type includes determining to apply Doppler / time domain compression or a Doppler / time domain base type in response to determining that the speed of the terminal device is greater than or equal to a predefined threshold speed or that the correlation between at least two CSI-RS resources is less than or equal to a predefined threshold, and determining not to apply Doppler / time domain compression or a Doppler / time domain base type in response to determining that the speed of the terminal device is less than a predefined threshold speed or that the correlation between at least two CSI-RS resources is greater than or equal to a predefined threshold.

[0440] FIG. 21 is a flowchart of an exemplary method 2100 implemented in a network device according to some embodiments of the present disclosure.

[0441] In block 2110, network device 120 receives from terminal device 110 an indication of whether Doppler / time domain compression or a Doppler / time domain base type is applied to report a precoding matrix indicator (PMI) to the network device. In block 2120, network device 120 processes the PMI reported by terminal device 110 based on the indication.

[0442] In some exemplary embodiments, an indication that Doppler / time domain compression or a Doppler / time domain base type is applied indicates a plurality of Doppler / time domain base vectors selected from a set of Doppler / time domain base vectors.

[0443] In some exemplary embodiments, a first matrix associated with the Doppler / time domain and indicated within at least one codebook information field in the PMI includes a plurality of Doppler / time domain base vectors.

[0444] In some exemplary embodiments, an indication that Doppler / time domain compression or Doppler / time domain basis type is not applied indicates a plurality of codebooks or a plurality of PMIs or a plurality of second matrices for different indices of time units associated with the Doppler / time domain but without Doppler / time domain compression, and each of the plurality of second matrices is associated with coefficients for the codebook.

[0445] In some exemplary embodiments, method 2100 further includes determining an index of a time unit based on an indication field for selecting a Doppler / time domain basis vector from a set of Doppler / time domain basis vectors.

[0446] In some exemplary embodiments, a first matrix associated with the Doppler / time domain and indicated within at least one codebook information field in the PMI is a replacement matrix.

[0447] In some exemplary embodiments, an indication that Doppler / time domain compression or Doppler / time domain basis type is not applied indicates a codebook that does not have a first matrix associated with the Doppler / time domain or does not have at least one codebook information field within the PMI.

[0448] In some exemplary embodiments, the codebook is indicated by one of the indicated set of Doppler / time domain basis vectors.

[0449] In some exemplary embodiments, the codebook is indicated by showing one column of a second matrix associated with coefficients for the codebook as non-zero and showing all elements within other columns of the second matrix as zero.

[0450] In some exemplary embodiments, the non-zero columns are represented by a bitmap having a size of 2L×Md×Mv, where 2L represents the number of spatial domain basis vectors, Md represents the number of Doppler / time domain basis vectors, and Mv represents the number of frequency domain basis vectors.

[0451] In some exemplary embodiments, method 2100 further includes determining that the columns of the strongest coefficients in the second matrix are after a first column having all zero coefficients.

[0452] In some exemplary embodiments, method 2100 further includes determining that the strongest coefficient of the second matrix associated with the coefficients for the codebook is in the first column of the second matrix.

[0453] In some exemplary embodiments, method 2100 further includes determining the bit size of the indication field of the strongest coefficient based on 2L that represents the number of spatial domain basis vectors, and determining the bit size of the indication field of the Doppler / time domain basis vectors based on Ns−1 and Md−1, where Md represents the number of Doppler / time domain basis vectors, and Ns represents one of the length of the Doppler / time domain basis vectors, the number of oversampled Doppler / time domain basis vectors, and the number of Doppler / time domain basis vectors within a window selected from the Doppler / time domain basis vectors or the oversampled Doppler / time domain basis vectors.

[0454] In some exemplary embodiments, when Doppler / time domain compression or Doppler / time domain basis type is applied, the first indication field (e.g., the indication field for element index) indicates the element index of the strongest coefficient in a predefined column of the second matrix, where the second matrix is associated with the coefficients for the codebook; when Doppler / time domain compression or Doppler / time domain basis type is not applied, the second indication field (e.g., the indication field for column index) indicates the column index of the strongest coefficient in the second matrix, and the first indication field indicates the element index of the strongest coefficient within the column.

[0455] In some exemplary embodiments, an indication of whether Doppler / time domain compression or Doppler / time domain basis type is applied is included in a first part of channel state information (CSI), and the first indication field and the second indication field are included in a second part of the CSI.

[0456] In some exemplary embodiments, when Doppler / time domain compression or Doppler / time domain basis type is applied, the indication field of the first size indicates the element index of the strongest coefficient in a predefined column of the second matrix, where the second matrix is associated with the coefficients for the codebook; when Doppler / time domain compression or Doppler / time domain basis type is not applied, the indication field of the second size indicates the column index and the element index within the column of the strongest coefficient in the second matrix.

[0457] In some exemplary embodiments, an indication of whether Doppler / time domain compression or Doppler / time domain basis type is applied is included in a first part of channel state information (CSI), and the indication field for the indication of the strongest coefficient is included in a second part of the CSI.

[0458] In some exemplary embodiments, method 2100 further includes determining a bit size for each of a plurality of phase coefficients in a second matrix based on the length of a Doppler / time domain basis vector, where the second matrix is associated with coefficients for a codebook.

[0459] In some exemplary embodiments, method 2100 further includes receiving, from a terminal device, at least one of the number of Doppler / time domain basis vectors, the length of the Doppler / time domain basis vectors, the length of a time unit associated with the Doppler / time domain, and a bitmap of non-zero coefficients in a second matrix associated with coefficients for a codebook, or transmitting, to the terminal device, at least one of the number of Doppler / time domain basis vectors, the length of the Doppler / time domain basis vectors, and the length of a time unit associated with the Doppler / time domain, where the at least one is set by a network device.

[0460] In some exemplary embodiments, method 2100 further includes determining the length of a time unit associated with the Doppler / time domain as a time interval between measurement channel state information (CSI)-reference signal (RS) resources.

[0461] In some exemplary embodiments, method 2100 further includes determining a rank indicator (RI) as 1 or 2 in response to application of Doppler / time domain compression or a Doppler / time domain basis type.

[0462] Details of some embodiments according to the present disclosure have been described with reference to FIGS. 12 to 20. Next, exemplary realizations of a terminal device and a network device will be described below.

[0463] The communication method includes determining, in a terminal device, whether to apply Doppler / time domain compression or a Doppler / time domain basis type in order to report a precoding matrix indicator (PMI) to a network device, and sending an indication of whether to apply Doppler / time domain compression or a Doppler / time domain basis type to the network device.

[0464] In one embodiment, an indication to apply Doppler / time domain compression or a Doppler / time domain basis type indicates a plurality of Doppler / time domain basis vectors selected from a set of Doppler / time domain basis vectors.

[0465] In one embodiment, a first matrix associated with the Doppler / time domain and indicated within at least one codebook information field in the PMI includes a plurality of Doppler / time domain basis vectors.

[0466] In one embodiment, an indication not to apply Doppler / time domain compression or a Doppler / time domain basis type indicates a plurality of codebooks or a plurality of PMIs or a plurality of second matrices for different indexes of time units associated with the Doppler / time domain but without Doppler / time domain compression, and each of the plurality of second matrices is associated with coefficients for the codebook.

[0467] In one embodiment, the method further includes selecting an index of a time unit based on an indication field for selecting a Doppler / time domain basis vector from a set of Doppler / time domain basis vectors.

[0468] In one embodiment, a first matrix associated with the Doppler / time domain and indicated within at least one codebook information field in the PMI is a replacement matrix.

[0469] In one embodiment, an indication not to apply Doppler / time domain compression or Doppler / time domain base type indicates a codebook that does not have a first matrix associated with the Doppler / time domain or does not have at least one codebook information field within the PMI.

[0470] In one embodiment, the codebook is indicated by indicating one of a set of Doppler / time domain base vectors as the Doppler / time domain base vector.

[0471] In one embodiment, the codebook is indicated by showing one column of a second matrix associated with the coefficients for the codebook as non-zero and showing all elements within the other columns of the second matrix as zero.

[0472] In one embodiment, the non-zero column is indicated by a bitmap having a size of 2L×Md×Mv, where 2L represents the number of spatial domain base vectors, Md represents the number of Doppler / time domain base vectors, and Mv represents the number of frequency domain base vectors.

[0473] In one embodiment, the method further includes arranging, in the second matrix, the column of the strongest coefficients after the first column having all-zero coefficients.

[0474] In one embodiment, the method further includes rotating the column including the strongest coefficients of the second matrix associated with the coefficients for the codebook to be the first column of the second matrix.

[0475] In one embodiment, the method further includes determining the bit size of the indication field of the strongest coefficient based on 2L representing the number of spatial domain basis vectors, and determining the bit size of the indication field of the Doppler / time domain basis vectors based on Ns - 1 and Md - 1, where Md represents the number of Doppler / time domain basis vectors, and Ns represents one of the length of the Doppler / time domain basis vectors, the number of oversampled Doppler / time domain basis vectors, and the number of Doppler / time domain basis vectors within a window selected from the Doppler / time domain basis vectors or the oversampled Doppler / time domain basis vectors.

[0476] In one embodiment, when Doppler / time domain compression or Doppler / time domain basis type is applied, the first indication field indicates the element index of the strongest coefficient of the second matrix within a predefined column of the second matrix, the second matrix being associated with the coefficients for the codebook, and when Doppler / time domain compression or Doppler / time domain basis type is not applied, the second indication field indicates the column index of the strongest coefficient within the second matrix, and the first indication field indicates the element index of the strongest coefficient within the column.

[0477] In one embodiment, the indication of whether to apply Doppler / time domain compression or Doppler / time domain basis type is included in a first part of channel state information (CSI), and the first indication field and the second indication field are included in a second part of the CSI.

[0478] In one embodiment, when Doppler / time domain compression or Doppler / time domain base type is applied, the indication field of the first size indicates the element index of the strongest coefficient within a predefined column of the second matrix, where the second matrix is associated with the coefficients for the codebook. When Doppler / time domain compression or Doppler / time domain base type is not applied, the indication field of the second size indicates the column index and the element index within the column for the strongest coefficient within the second matrix.

[0479] In one embodiment, an indication of whether to apply Doppler / time domain compression or Doppler / time domain base type is included in a first part of channel state information (CSI), and an indication field for the indication of the strongest coefficient is included in a second part of the CSI.

[0480] In one embodiment, the method further includes determining, based on the length of the Doppler / time domain base vector, the bit size for indicating each of a plurality of phase coefficients within the second matrix, where the second matrix is associated with the coefficients for the codebook.

[0481] In one embodiment, the method further includes reporting to the network device at least one of the number of Doppler / time domain base vectors, the length of the Doppler / time domain base vector, the length of the time unit associated with the Doppler / time domain, and the bitmap of non-zero coefficients within the second matrix associated with the coefficients for the codebook, or receiving from the network device at least one of the number of Doppler / time domain base vectors, the length of the Doppler / time domain base vector, and the length of the time unit associated with the Doppler / time domain, which are set by the network device.

[0482] In one embodiment, the method further includes determining the length of the time unit associated with the Doppler / time domain as the time interval between measurement channel state information (CSI)-reference signal (RS) resources.

[0483] In one embodiment, the method further includes determining the rank indicator (RI) as 1 or 2 in response to applying Doppler / time domain compression or a Doppler / time domain base type.

[0484] In one embodiment, determining whether to apply Doppler / time domain compression or a Doppler / time domain base type includes determining to apply Doppler / time domain compression or a Doppler / time domain base type in response to determining that the speed of the terminal device is greater than or equal to a predefined threshold speed or the correlation between at least two CSI-RS resources is less than or equal to a predefined threshold, and determining not to apply Doppler / time domain compression or a Doppler / time domain base type in response to determining that the speed of the terminal device is less than a predefined threshold speed or the correlation between at least two CSI-RS resources is greater than or equal to a predefined threshold.

[0485] A method for communication includes receiving, at a network device, an indication from a terminal device as to whether Doppler / time domain compression or a Doppler / time domain base type is applied to report a precoding matrix indicator (PMI) to the network device, and processing the PMI reported by the terminal device based on the indication.

[0486] In one embodiment, an indication that Doppler / time domain compression or a Doppler / time domain base type is applied indicates a plurality of Doppler / time domain base vectors selected from a set of Doppler / time domain base vectors.

[0487] In one embodiment, a first matrix associated with the Doppler / time domain and indicated within at least one codebook information field in the PMI includes a plurality of Doppler / time domain basis vectors.

[0488] In one embodiment, an indication that Doppler / time domain compression or Doppler / time domain basis type is not applied indicates a plurality of codebooks or a plurality of PMIs or a plurality of second matrices for different indices of time units associated with the Doppler / time domain but without Doppler / time domain compression, and each of the plurality of second matrices is associated with coefficients for the codebook.

[0489] In one embodiment, the method further includes determining an index of a time unit based on an indication field for selecting a Doppler / time domain basis vector from a set of Doppler / time domain basis vectors.

[0490] In one embodiment, a first matrix associated with the Doppler / time domain and indicated within at least one codebook information field in the PMI is a replacement matrix.

[0491] In one embodiment, an indication that Doppler / time domain compression or Doppler / time domain basis type is not applied indicates a codebook that does not have a first matrix associated with the Doppler / time domain or does not have at least one codebook information field within the PMI.

[0492] In one embodiment, the codebook is indicated by one of the indicated set of Doppler / time domain basis vectors.

[0493] In one embodiment, the codebook is shown by showing one column of a second matrix associated with the coefficients for the codebook as non-zero and showing all elements in the other columns of the second matrix as zero.

[0494] In one embodiment, the non-zero column is shown by a bitmap having a size of 2L×Md×Mv, where 2L represents the number of spatial-domain basis vectors, Md represents the number of Doppler / time-domain basis vectors, and Mv represents the number of frequency-domain basis vectors.

[0495] In one embodiment, the method further includes determining that the columns of the strongest coefficients in the second matrix are after the first column having all-zero coefficients in the second matrix.

[0496] In one embodiment, the method further includes determining that the strongest coefficient of the second matrix associated with the coefficients for the codebook is in the first column of the second matrix.

[0497] In one embodiment, the method further includes determining the bit size of the indication field of the strongest coefficient based on 2L representing the number of spatial-domain basis vectors, and determining the bit size of the indication field of the Doppler / time-domain basis vectors based on Ns−1 and Md−1, where Md represents the number of Doppler / time-domain basis vectors, and Ns represents one of the length of the Doppler / time-domain basis vectors, the number of oversampled Doppler / time-domain basis vectors, and the number of Doppler / time-domain basis vectors within a window selected from the Doppler / time-domain basis vectors or the oversampled Doppler / time-domain basis vectors.

[0498] In one embodiment, when the Doppler / time domain compression or Doppler / time domain basis type is applied, the first indication field indicates the element index of the strongest coefficient in a predefined column of the second matrix, where the second matrix is associated with the coefficients for the codebook. When the Doppler / time domain compression or Doppler / time domain basis type is not applied, the second indication field indicates the column index of the strongest coefficient in the second matrix, and the first indication field indicates the element index of the strongest coefficient within the column.

[0499] In one embodiment, an indication of whether the Doppler / time domain compression or Doppler / time domain basis type is applied is included in a first part of the channel state information (CSI), and the first indication field and the second indication field are included in a second part of the CSI.

[0500] In one embodiment, when the Doppler / time domain compression or Doppler / time domain basis type is applied, the first size indication field indicates the element index of the strongest coefficient in a predefined column of the second matrix, where the second matrix is associated with the coefficients for the codebook. When the Doppler / time domain compression or Doppler / time domain basis type is not applied, the second size indication field indicates the column index and the element index within the column of the strongest coefficient in the second matrix.

[0501] In one embodiment, an indication of whether the Doppler / time domain compression or Doppler / time domain basis type is applied is included in a first part of the channel state information (CSI), and the indication field for the indication of the strongest coefficient is included in a second part of the CSI.

[0502] In one embodiment, the method further includes determining a bit size for each of a plurality of phase coefficients in a second matrix based on a length of a Doppler / time domain basis vector, where the second matrix is associated with coefficients for a codebook.

[0503] In one embodiment, the method further includes receiving, from a terminal device, at least one of a number of Doppler / time domain basis vectors, a length of a Doppler / time domain basis vector, a length of a time unit associated with the Doppler / time domain, and a bitmap of non-zero coefficients in a second matrix associated with coefficients for a codebook, or transmitting, to the terminal device, at least one of a number of Doppler / time domain basis vectors, a length of a Doppler / time domain basis vector, and a length of a time unit associated with the Doppler / time domain, where the at least one is set by a network device.

[0504] In one embodiment, the method further includes determining a length of a time unit associated with the Doppler / time domain as a time interval between measurement channel state information (CSI)-reference signal (RS) resources.

[0505] In one embodiment, the method further includes determining a rank indicator (RI) as 1 or 2 in response to a Doppler / time domain compression or a Doppler / time domain basis type being applied.

[0506] The terminal device includes a processor and a memory coupled to the processor and storing instructions, where when the instructions are executed by the processor, the method according to the communication method is performed.

[0507] The network device includes a processor and a memory coupled to the processor and storing instructions, and when the instructions are executed by the processor, it executes the method according to the above communication method.

[0508] The computer-readable medium stores instructions that, when executed on at least one processor, cause the at least one processor to execute the method according to the above communication method.

Claims

1. A method of communication, comprising: at a terminal device, determining a first set of channel quality indicators (CQIs) conditional on a first precoding matrix indicator (PMI) corresponding to a first time unit, wherein a second timing of the first time unit is after a first timing of a first time interval for reporting channel state information (CSI); transmitting a CSI report including the first set of CQIs and the first PMI to a network device within the first time interval; The method comprising the above steps.

2. The first time unit is the first time unit after a third timing or among subsequent time units, and the third timing includes at least one of: the first timing; a start or end of a time interval corresponding to an index determined based on a first index + M of the first time interval, where M is a non-negative integer. The method according to claim 1.

3. The first set of CQIs includes at least one of a first wideband CQI and a first plurality of subband CQIs. The method according to claim 2.

4. The CSI report includes a plurality of sets of CQIs associated with a first plurality of time units, the plurality of sets of CQIs includes the first set of CQIs, one set of CQIs among the plurality of sets of CQIs is associated with a time unit among the first plurality of time units and includes at least one of a wideband CQI and a plurality of subband CQIs, and the at least one of the wideband CQI and the plurality of subband CQIs is determined based on a PMI corresponding to the associated time unit. The method according to claim 1.

5. The CSI report further includes at least one of a second set of CQIs associated with a second time unit and a third set of CQIs associated with a third time unit, the second time unit is different from the first time unit, and the third time unit is different from the second time unit. The method according to claim 1.

6. The method according to claim 1. The method according to claim 1. The method according to claim 1. The method according to claim 1.

6. The CQI of the second set includes at least one of a second wideband CQI and a plurality of second sub-band CQIs, and the at least one of the second wideband CQI and the plurality of second sub-band CQIs is determined based on a second PMI corresponding to the second time unit. The CQI of the third set includes at least one of a third wideband CQI and a plurality of third sub-band CQIs, and the at least one of the third wideband CQI and the plurality of third sub-band CQIs is determined based on a third PMI corresponding to the third time unit. The method according to claim 1.

7. Sending the CSI report includes sending the CQI of the first set within a first part of the CSI report; and sending at least one of the CQI of the second set and the CQI of the third set within a second part of the CSI report. The method according to claim 1.

8. Sending the CSI report includes sending the CQI of the second set in response to the difference between the CQI of the second set and the CQI of the first set exceeding a first threshold; and at least one of sending the CQI of the third set in response to the difference between the CQI of the third set and the CQI of the second set exceeding a second threshold. The method according to claim 10.

9. Among the plurality of sets of CQI, the payload of the wideband CQI among one set of CQI with index i ＣＱＩ is as follows Index i ＣＱＩ The first number of bits indicating the value for the wideband CQI among the set of CQIs having Index i ＣＱＩ The third number of bits indicating the difference value between the wideband CQI among the set of CQIs having ＣＱＩ and the wideband CQI among the first set of CQIs, or Index i ＣＱＩ Among the set of CQIs having the wideband CQI and index i ＣＱＩ The third number of bits indicating the difference value between the wideband CQI among the set of CQIs having -1, includes at least one of them Index i ＣＱＩ For one sub-band CQI out of a plurality of sub-band CQIs of the set of CQIs having Index i ＣＱＩ One of the plurality of sub-band CQIs among the set of CQIs having index i and index i ＣＱＩ The second number of bits indicating the difference value from the wideband CQI among the set of CQIs having index i, and Index i ＣＱＩ the third number of bits indicating a difference value between the one sub-band CQI among the plurality of sub-band CQIs of the set of CQIs having the Index i ＣＱＩ one of the plurality of sub-band CQIs among the set of CQIs having an index i and index i ＣＱＩ the second number of bits or the third number of bits indicating a difference value from one of the plurality of sub-band CQIs among the set of CQIs having -1 at least one of the third number of bits indicating a difference value between the one sub-band CQI among the second plurality of sub-band CQIs and the wideband CQI having an index i - 1 among the one set of CQIs ＣＱＩ is included, i ＣＱＩ is a positive integer, and i ＣＱＩ is greater than 1 The method according to claim 4.

10. The payload of the second wideband CQI includes a third number of bits indicating a difference value between the second wideband CQI and the first wideband CQI. The payload of the second sub-band CQI among the plurality of second sub-band CQIs includes at least one of the third number of bits indicating a difference value between the second sub-band CQI and the first wideband CQI; the second number of bits indicating a difference value between the second sub-band CQI and the second wideband CQI; and the third number of bits indicating a difference value between the second sub-band CQI and one sub-band CQI among the first plurality of sub-band CQIs. The method according to claim 5.

11. The payload of the third wideband CQI includes either the third number of bits indicating a difference value between the third wideband CQI and the second wideband CQI, or the third number of bits indicating a difference value between the third wideband CQI and the first wideband CQI. The payload of the third sub-band CQI among the third plurality of sub-band CQIs is the second number of bits indicating the difference value between the third sub-band CQI and the third wideband CQI, the third number of bits indicating the difference value between the third sub-band CQI and the second sub-band CQI, or any one of the third number of bits indicating the difference value between the third sub-band CQI and the first sub-band CQI among the first plurality of sub-band CQIs, The method according to claim 5.

12. The payload of the third wideband CQI includes the first number of bits indicating the absolute value for the third wideband CQI, The payload of the third sub-band CQI among the third plurality of sub-band CQIs includes the second number of bits or the third number of bits indicating the difference value between the third sub-band CQI and the third wideband CQI The method according to claim 5.

13. The first time unit is the start time unit among the first plurality of time units, and a second plurality of time units including the second number of time units determined from the first plurality of time units, wherein each time unit is the start time unit among the second plurality of time units that is after or at the same time as the first timing, the time unit corresponding to the strongest one set of CQIs among the plurality of sets of CQIs, wherein the strongest one set of CQIs includes the wideband CQI or the sub-band CQI having the maximum value among the plurality of sets of CQIs, and the CSI report includes the index value of the time unit corresponding to the strongest one set of CQIs, one of The method according to claim 1.

14. Transmitting the CSI report includes transmitting an indication field within the second part of the CSI report, the indication field indicating the first plurality of time units The method according to claim 4.

15. The payload of the indication field is determined based on the fourth number of time units among the first plurality of time units and the number of sets of CQIs among the plurality of CQIs The method according to claim 14.

16. The first set of CQIs includes a set of CQIs associated with a predetermined time unit among the first plurality of time units, and the predetermined time unit is the start time unit among the first plurality of time units, and the start time unit among the second plurality of time units, including at least one of the time unit corresponding to the strongest set of CQIs the payload of the indication field the result of subtracting 1 from the fourth number and the result of subtracting 1 from the number of CQI sets determined based on one of the result of subtracting 1 from the fifth number of time units within the second plurality of time units and the result of subtracting 1 from the number of CQI sets The method according to claim 15.

17. A communication method, in a network device, receiving, from a terminal device, a channel state information (CSI) report including a first set of channel quality indicators (CQIs) and a first precoding matrix indicator (PMI) within a first time interval, wherein the first set of CQIs is conditional on the first PMI, the first PMI corresponds to a first time unit, and a second timing of the first time unit is after a first timing of the first time interval for reporting the CSI method.

18. A terminal device comprising a processor and a memory coupled to the processor and storing instructions, wherein when the instructions are executed by the processor, the method according to any one of claims 1 to 16 is performed terminal device.

19. A network device comprising a processor and a memory coupled to the processor and storing instructions, wherein when the instructions are executed by the processor, the method according to claim 17 is performed network device.

20. storing instructions for causing at least one processor to perform the method according to any one of claims 1 to 16 or the method according to claim 17 when executed on at least one processor computer-readable medium.

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