Channel state information measurement and calculation method and related user equipment

Abstract

A method for calculating and reporting downlink channel state information (DL CSI) is proposed to support high-speed scenarios in new radio (NR) systems. In a first novel aspect, two CSI reference time slots are defined. A CSI reference time slot for CSI measurement is defined to determine which CSI-RS / SSB timing to use for CSI calculation. A CSI reference time slot for CSI calculation is defined to determine a time slot where the UE assumes the CSI calculation should be based on that time slot and subsequent channels. In a second novel aspect, the UE can be configured with a CSI calculation period consisting of one or N time slots, and can be divided into multiple non-overlapping sub-periods. The UE can be configured to calculate and report the broadband CSI for the entire CSI calculation period and / or the subband CSI for each sub-period.

Description

[0001] Cross-referencing This application is a divisional application of the invention patent application with application number 202210720627.9, entitled "Method for measuring and calculating channel state information and related user equipment".

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 218,438, filed July 5, 2021, entitled “Extension of CSI Framework to Support High Mobility,” which is incorporated herein by reference in its entirety. Technical Field

[0003] The disclosed embodiments generally relate to mobile communication networks, and more specifically to a method for calculating channel state information (CSI) to support high-speed scenarios. Background Technology

[0004] Fifth-generation new radio (5G NR) is an improved radio access technology (RAT) that offers higher data rates, greater reliability, lower latency, and improved system capacity. In an NR system, the terrestrial radio access network comprises multiple base stations (BSs), called next-generation node base stations (gNBs), communicating with multiple mobile stations (called user equipment (UEs)). UEs can communicate with base stations (BSs) or gNBs via downlink and uplink. Downlink (DL) refers to communication from the base station to the UE. Uplink (UL) refers to communication from the UE to the base station. The 5G NR standard is defined by 3GPP. UEs use Channel State Information Reference Signals (CSI-RS) to measure and feedback the characteristics of the radio channel so that the gNB can transmit DL data using the correct modulation, code rate, beamforming, etc.

[0005] In practical development, a significant drop in throughput was observed in high-speed or medium-speed scenarios. A major reason is that reported CSIs become outdated due to rapid channel changes. Channel changes can be observed in the Doppler domain. In the current NR, CSIs are calculated based on the time slot where the CSI reference resource is located, which is before the uplink time slot where the CSI is reported. When the gNB needs to perform scheduling, CSIs calculated for past time slots may be useless later, especially in high-speed scenarios. To improve throughput, the gNB needs to know CSIs that are beneficial for "future" channels. Future CSIs cannot be learned through "one-time" measurements because any channel change requires at least two measurements to detect.

[0006] We are seeking a solution to extend the CSI framework in NR to support high-speed scenarios. Summary of the Invention

[0007] A downlink channel state information (DL CSI) calculation and reporting method is proposed to support high-speed scenarios in new radio (NR) systems. In a first novel aspect, two CSI reference time slots are defined. A CSI reference time slot for CSI measurement is defined to determine which CSI-RS / SSB timing to use for CSI calculation. A CSI reference time slot for CSI calculation is defined to determine a time slot from which the UE assumes the CSI calculation should be based on the channel from the start of that time slot onwards. In a second novel aspect, the UE can be configured with a CSI calculation period consisting of one or N time slots, and can be divided into multiple non-overlapping sub-periods. The UE can be configured to calculate and report the broadband CSI and subband CSI for the entire CSI calculation period and / or each sub-period.

[0008] In one embodiment, the UE receives Channel State Information (CSI) configuration information from the base station (BS). The UE determines a first CSI reference time slot for measurement and a second CSI reference time slot for calculation based on the CSI configuration information. The second CSI reference time slot occurs after the first CSI reference time slot in the time domain. The UE measures the CSI reference signal (CSI) of the downlink channel received before the first CSI reference time slot for measurement. The UE calculates the CSI of the downlink channel based on the second CSI reference time slot for calculation. The UE estimates and predicts the CSI of the downlink channel starting from the second CSI reference time slot for calculation.

[0009] In another embodiment, the UE receives Channel State Information (CSI) configuration information from the base station (gNB). The CSI configuration includes CSI resources and a CSI calculation period, which has one or more non-overlapping sub-periods within the time domain. The UE measures multiple timings of the CSI of the downlink channel received through the configured CSI resources. The UE uses the timing correlation of the multiple CSI timings to estimate the CSI of the downlink channel for the CSI calculation period. The UE reports the estimated downlink channel CSI to the gNB and the estimated CSI according to the configured CSI calculation period.

[0010] This application provides a method and apparatus for CSI measurement and calculation in high-speed scenarios in extended NR that is beneficial to "future" channels. Further embodiments and advantages are described in the detailed description below. This overview is not intended to define the invention. The invention is defined by the scope of the claims. Attached Figure Description

[0011] Figure 1The illustration depicts a novel radio (NR) mobile communication network that uses Channel State Information Reference Signal (CSI-RS) for high-speed scenarios for measurement, calculation, and reporting, based on a novel aspect.

[0012] Figure 2 This is a simplified block diagram of a base station and user equipment implementing certain embodiments of the present invention.

[0013] Figure 3 The diagram illustrates the sequence flow of the entire process for CSI acquisition and reporting according to a novel aspect.

[0014] Figure 4 A first embodiment of a CSI reference time slot for measurement and a CSI reference time slot for calculation, based on a novel aspect, is shown to support high-speed scenarios.

[0015] Figure 5 The illustration shows a second embodiment of configuring the CSI computation cycle with full-cycle CSI and sub-cycle CSI according to a novel aspect to support high-speed scenarios.

[0016] Figure 6 The illustration shows an example of CSI calculation cycles with full-cycle CSI and sub-cycle CSI for broadband and sub-band.

[0017] Figure 7 The illustration shows an example of CSI calculations and reporting based on a novel aspect to support high-speed scenarios.

[0018] Figure 8 This is a flowchart of a method for using CSI reference time slots for measurement and CSI reference time slots for calculation to support high-speed scenarios, based on a novel application.

[0019] Figure 9 This is a flowchart of a novel approach to configuring the CSI calculation cycle from the UE's perspective to support high-speed scenarios. Detailed Implementation

[0020] Reference will now be made in detail to some embodiments of the invention, examples of which are shown in the accompanying drawings.

[0021] Figure 1The illustration depicts a novel radio (NR) mobile communication network 100 that measures, calculates, and reports based on a novel aspect of a high-speed channel state information reference signal (CSI-RS). The mobile communication network 100 is an OFDM network comprising a serving base station (gNB 101) and user equipment (UE 102). In a 3GPP NR system based on OFDMA downlink, radio resources are divided into multiple time slots in the time domain, each time slot consisting of multiple OFDMA symbols. Each OFDMA symbol is further composed of multiple OFDMA subcarriers in the frequency domain, depending on the system bandwidth. The basic unit of the resource grid is called a resource element (RE), which spans one OFDMA symbol on one OFDMA subcarrier. REs are grouped into resource blocks (RBs), where each RB consists of twelve consecutive subcarriers in one time slot.

[0022] Several physical downlink channels and reference signals are defined to carry information originating from higher layers using a set of resource elements. For downlink channels, the Physical Downlink Shared Channel (PDSCH) is the primary downlink channel carrying data in NR, while the Physical Downlink Control Channel (PDCCH) carries downlink control information (DCI). Control information may include scheduling decisions, information related to reference signal information, rules for forming the corresponding transport blocks (TBs) to be carried by the PDSCH, and power control commands. For Radio Resource Management (RRM) measurements in NR, each UE can be configured to measure Synchronization Signal (SS) Blocks (SSBs) and / or Channel State Information (CSI) Reference Signals (CSI-RS). For CSI-RS measurements, frequency and time resources need to be determined. The UE uses CSI-RS to measure and feedback the characteristics of the DL channel so that the gNB can transmit DL data using the correct modulation, code rate, beamforming, etc.

[0023] In actual development, a significant drop in throughput was observed in high-speed or medium-speed scenarios. A major reason is that reported CSI (Channel Indicator) data becomes outdated due to rapid channel changes. According to a novel aspect, such as... Figure 1As shown, a CSI acquisition and reporting approach is proposed to support high-speed scenarios. In a novel aspect, two CSI reference time slots are defined. A CSI reference time slot for CSI measurement is defined to determine which CSI-RS / SSB timing to use for CSI calculation. A CSI reference time slot for CSI calculation is defined to determine the first time slot, which is the first time slot from which the UE assumes the CSI calculation should be based on the channel starting from that time slot. For example, if CSI reporting occurs in time slot (n), the CSI reference time slot for CSI measurement appears in time slot (n-nCSI_REF), while the CSI reference time slot for calculation appears in slot (n+K). In another novel aspect, the UE can be configured with a CSI calculation period consisting of one or N time slots, and can be divided into multiple non-overlapping sub-periods. The UE can be configured to calculate and report broadband CSI and subband CSI for the entire CSI calculation period and / or each sub-period.

[0024] Figure 2 This is a simplified block diagram of a base station 201 and a user equipment 211 that execute certain embodiments of the present invention in a mobile communication network 200. For the base station 201, an antenna 221 transmits and receives radio signals. An RF transceiver module 208 (abbreviated as transceiver in the figures) is coupled to the antenna, receives RF signals from the antenna, converts them into baseband signals, and sends them to the processor 203. The RF transceiver 208 also converts the received baseband signals from the processor into RF signals and transmits them to the antenna 221. The processor 203 processes the received baseband signals and calls different functional modules to perform functions in the base station 201. A memory 202 stores program instructions and data 209 (abbreviated as program in the figures) to control the operation of the base station.

[0025] A similar configuration exists in UE 211, where antenna 231 transmits and receives RF signals. An RF transceiver module 218 (abbreviated as transceiver in the figures) is coupled to the antenna, receives RF signals from the antenna, converts them into baseband signals, and sends them to processor 213. RF transceiver 218 also converts baseband signals received from the processor, converts them into RF signals, and sends the output to antenna 231. Processor 213 processes the received baseband signals and calls different functional modules to execute features in UE 211. Memory 212 stores program instructions and data 219 (abbreviated as program in the figures) to control the operation of the UE.

[0026] Base station 201 and UE 211 also include several functional modules and circuits to perform some embodiments of the present invention. Different functional modules are circuits that can be configured and implemented by software, firmware, hardware, or any combination thereof. When executed by processors 203 and 213 (e.g., by executing programs 209 and 219), the functional modules and circuits, for example, allow base station 201 to schedule (via scheduler 204), precode (via precoder 205), encode (via MIMO encoding circuitry 206), and send control / configuration information and data (via control / configuration circuitry (CTL / CFG) 207) to UE 211, and allow UE 211 to receive control / configuration information and data (via control / configuration circuitry (CTL / CFG) 217), measure CSI reference signals (via measurement circuitry 216), estimate CSI (via estimation circuitry 215), and report the estimated CSI accordingly (via reporting circuitry 220).

[0027] Figure 3 The diagram illustrates the sequence flow of the entire process for CSI acquisition and reporting according to a novel aspect. In step 311, gNB 301 provides CSI configuration information to UE 302 for CSI acquisition and reporting. The CSI configuration information may include CSI reference signal configuration, CSI reference resource configuration, CSI reporting configuration, CSI reference time slots for CSI measurement, CSI reference time slots for CSI calculation, and CSI calculation period, etc. In step 312, gNB 301 transmits multiple opportunities for CSI reference signals to UE 302 based on the configured CSI-RS resources. In step 321, UE 302 receives multiple opportunities for multiple CSI reference signals, estimates the effective downlink channel, and performs CSI calculation based on the CSI configuration information.

[0028] In a novel aspect, two CSI reference time slots are defined. A CSI reference time slot for CSI measurement is defined to determine which CSI-RS is used to calculate the CSI. A CSI reference time slot for CSI calculation is defined to determine the UE's assumption that the CSI calculation should be based on the first time slot of the channel starting from that time slot. In another novel aspect, UE 302 can be configured by gNB 301 to have a CSI calculation period consisting of one or N time slots, and can be divided into multiple non-overlapping sub-periods. In step 322, UE 302 reports the calculated CSI to gNB based on the CSI configuration information. The reported CSI parameters may include a rank indicator (RI), a precoding matrix indicator (PMI), and a channel quality index (CQI). In step 331, gNB 301 receives the CSI feedback and determines scheduling parameters for subsequent PDSCH transport block (TB) transmissions. In step 341, gNB 301 transmits data to UE 302 via PDSCH using determined parameters including modulation, code rate, and beamforming.

[0029] Figure 4 A first embodiment of a CSI reference time slot for measurement and a CSI reference time slot for calculation, based on a novel aspect, is illustrated to support high-speed scenarios. The CSI reference signal (CSI-RS) is a dedicated measurement signal introduced for use by the UE to obtain CSI, for example, for channel-dependent scheduling, link adaptation, and transmission settings related to multi-antenna transmission. The UE is configured to calculate CSI based on a single timing or multiple CSI-RS timings on configured CSI reference resources (e.g., a set of downlink frequency and time domain resource blocks). The CSI reference resources of the serving cell are defined as follows: In the frequency domain, the CSI reference resources are defined by a set of downlink physical resource blocks corresponding to the frequency band associated with the derived CQI value. In the time domain, the CSI reference resources are defined by a single downlink time slot or specific subframe associated with the derived CQI value. In the spatial / layer domain, the CSI reference resources are defined by the RI and PMI associated with the derived CQI value.

[0030] In the current NR, CSI is calculated based on the slot location of the CSI reference resource, which precedes the uplink slot used for CSI reporting. However, CSI calculated for past slots may be useless later when the gNB needs to perform scheduling, especially in high-speed scenarios. To improve throughput, the gNB needs to know the CSI for "future" channels when channel changes are significant. Future CSI cannot be learned through a "one-off" measurement because any channel change requires at least two measurements to detect. In a novel aspect, the UE can be configured to measure CSI-RS on multiple occasions across multiple slots of past DL channels, and the UE can also be configured to calculate and predict the CSI for future DL channels based on detected channel changes from multiple CSI-RS measurements.

[0031] Specifically, two CSI reference time slots are defined to support high-speed scenarios. A CSI reference time slot for CSI measurement is defined to determine which CSI-RS is used to calculate the CSI. A CSI reference time slot for CSI calculation is defined to determine the first time slot, which is the first time slot the UE assumes the CSI calculation should be based on the current channel. When the UE is configured to calculate CSI based on a single CSI-RS timing, the two CSI reference time slots overlap and are the same as the CSI reference resource for Rel-15 NR. When the UE is configured to calculate CSI based on multiple CSI-RS timings, the CSI reference time slot for CSI measurement is the same as the CSI reference resource for Rel-15 NR to determine which CSI-RS timing to use for CSI calculation. When the UE is configured to calculate CSI based on multiple CSI-RS timings, the CSI reference time slot for CSI calculation can be configured to be the same as or after the uplink time slot used for CSI reporting. Multiple CSI-RS opportunities can be multiple repetitions within a burst cycle, or multiple CSI-RS resources in a cross-timeslot CSI-RS resource set no later than the CSI reference resource.

[0032] exist Figure 4In this embodiment, the UE is configured to calculate the CSI based on multiple timings of the CSI-RS and report the CSI at time slot n. The CSI reference time slot used for CSI measurement is the same as the CSI reference resource that appears before time slot n with an offset of nCSI_ref, for example, at time slot (n-nCSI_ref). That is, the UE calculates the CSI based on multiple timings of the CSI-RS received and measured no later than time slot (n-nCSI_ref). The CSI reference time slot used for CSI calculation can be configured after the uplink time slot used for CSI reporting, with an offset of K, for example, at time slot (n+K). That is, the CSI calculated by the UE is for a future time, starting from time slot (n+K), where the UE assumes that the CSI calculation should be predicted on the channel starting at a future time from time slot (n+K). Traditionally, due to rapid channel changes, CSI calculated on past CSI reference resources (e.g., slot (n-nCSI_ref)) becomes outdated for future times (e.g., slot (n+K)). By configuring two separate CSI reference slots for CSI measurement and CSI calculation, the UE can calculate and predict future CSI in slot (n+K) based on multiple moments of CSI-RS received and measured no later than slot (n-nCSI_ref). For example, CSI prediction can use an autoregressive (AR) model. Multiple CSI-RS measurements can be used to estimate the AR coefficient {ci}. This equation can then be applied recursively. To calculate .

[0033] Figure 5 The illustration shows a second embodiment of configuring a CSI calculation cycle with full-cycle CSI and sub-cycle CSI to support high-speed scenarios according to a novel aspect. The UE can configure a CSI calculation cycle consisting of one or more time slots and can be divided into multiple non-overlapping sub-cycles. Each sub-cycle consists of X consecutive time slots, where X is configurable. The CSI calculated for the entire CSI calculation cycle is called the "full-cycle" CSI. The CSI calculated for a sub-cycle is called the "sub-cycle" CSI. A CSI calculation cycle can begin from a CSI reference time slot used for CSI calculation. The CSI calculation cycle can be set before the CSI resource reference specified in NRRrelease 15.

[0034] exist Figure 5In the example, in the time domain, sub - periods SUB - P 0, SUB - P 1, ……, SUB - P P - 1 are defined. In the frequency domain, sub - bands SUB - B 0, SUB - B 1, ……, SUB - B B - 1 are defined. The size of the sub - period depends on the total number of time slots in the CSI calculation period. If the number of time slots in CSI calculation period A is greater than that in CSI calculation period B, then the sub - period size of A is greater than or equal to that of B. When the number of time slots in the CSI calculation period is less than or equal to a certain predefined value, only the CSI of the whole period is reported. If none of the time slots in the CSI calculation period includes at least one downlink or flexible symbol configured by a higher layer, the reporting of the CSI of the whole period is omitted. A valid sub - period is a sub - period in which all time slots include at least one downlink or flexible symbol configured by a higher layer. If a sub - period is not a valid sub - period, the reporting of the sub - period CSI is ignored. Starting from the first valid sub - period, only the valid sub - periods are indexed. The gNB can notify the UE which sub - periods can be omitted for CSI reporting. The omitted sub - periods are regarded as invalid sub - periods.

[0035] In a preferred embodiment, the CSI report is configured to be in time slot n, and the CSI calculation period starts from the CSI reference time slot for CSI calculation, for example, time slot (n + K), as Figure 5 shown. Since the UE is configured to calculate CSI based on the timing of multiple CSI - RSs measured no later than time slot (n - nCSI_ref), the UE can consider the time - domain correlation of multiple CSI - RSs to predict the CSI in time slot (n + K). In addition, the UE is configured with a CSI calculation period (e.g., across multiple time slots), which has a complete period and multiple non - overlapping sub - periods, and this can utilize the time - domain correlation. The CSI calculation period aims to help reduce the CSI feedback overhead. If N time slots within the same sub - period can share the same CSI with little performance loss, the overhead is reduced to 1 / N. In addition, the change of the channel over time is usually sparse in the transform domain, such as the Doppler domain (through DFT). Then, M' << M values can be used to describe M sub - periods, for example, M' / M = .

[0036] In another alternative embodiment, CSI reporting is configured to occur in slot n, and the CSI calculation period ends at the CSI reference slot used for CSI measurement, which is the same as the CSI reference resource, e.g., slot (n - nCSI_ref) (not shown). The goal is to allow the gNB to predict future CSIs, so the UE should calculate the CSI only based on past observations. In this case, the UE measures the CSI-RS received no later than slot (n - nCSI_ref) and calculates the CSI using a calculation period ending in the same slot. The UE still considers the temporal correlation of the entire calculation period to estimate the CSI of the DL channel while reducing CSI feedback overhead. However, the UE does not need to make any predictions for the CSI of the DL channel starting from a future slot (n+K). The UE simply reports the calculated past CSIs to the network, and the network can use the received past CSIs to predict future CSIs.

[0037] Figure 6 The illustration shows an example of CSI calculation cycles with full-cycle CSI and sub-cycle CSI for both broadband and subband. The gNB can be configured to calculate different combinations of CSI for the UE. For example... Figure 6 As shown in (a), the UE can be configured to calculate the broadband CSI over the entire CSI calculation period. The UE assumes that the gNB will apply the calculated CSI to the entire bandwidth over the entire CSI calculation period. Figure 6 As shown in (b), the UE can be configured to calculate the subband CSI for the entire CSI calculation period. For each subband CSI, the UE assumes that the gNB will apply the calculated CSI to the referenced subband throughout the entire CSI calculation period. In this example, three subbands, SUB-B 0, SUB-B 1, and SUB-B 2, are defined, and the UE is configured to calculate the subband CSIs for SUB-B 0, SUB-B 1, and SUB-B 2 for the entire CSI calculation period.

[0038] like Figure 6 As depicted in (c), the UE can be configured to calculate the broadband CSI for each sub-cycle. The UE assumes that each calculated CSI will be applied by the gNB to the entire bandwidth within the specified sub-cycle. In this example, three sub-cycles, SUB-P0, SUB-P1, and SUB-P2, are defined, and the UE is configured to calculate the CSI for the entire bandwidth in each of the three sub-cycles, SUB-P0, SUB-P1, and SUB-P2. Figure 6As shown in (d), the UE can be configured to calculate the subband CSI for each sub-cycle. The UE assumes that each calculated CSI will be applied by the gNB to a reference subband in a reference sub-cycle. In this example, three subbands SUB-B 0, SUB-B 1, and SUB-B 2 are defined, and three sub-cycles SUB-P 0, SUB-P 1, and SUB-P 2 are defined. The UE is configured to calculate the subband CSI (0-8) for SUB-B 0, SUB-B 1, and SUB-B 2 in the three sub-cycles SUB-P 0, SUB-P 1, and SUB-P 2.

[0039] Figure 7 The illustration shows an example of CSI calculation and reporting based on a novel aspect to support high-speed scenarios. In one embodiment, the gNB can inform the UE which sub-periods can be omitted from the CSI report. Omitted sub-periods are considered invalid sub-periods. Figure 7 In the example of (a), sub-slots 1 and 5 are omitted according to the gNB notification, and sub-slot 2 is omitted because no time slot includes at least one downlink or flexible symbol configured at a higher layer. Therefore, the UE only needs to report the sub-period CSI for SUB-P 0 (0), SUB-P 3 (1), and SUB-P 4 (2). In another embodiment, the gNB can configure the UE to report the sub-period CQI only for the best K sub-periods in the CSI calculation period, where K is configurable. Figure 7 In the example of (b), the CQI of each sub-period (sub-periods) of sub-periods 1, 2, and 4 is superior to the CQI of sub-periods 0, 3, and 5. If K=3, then only the UE reports the sub-period CQIs of SUB-P 1 (0), SUB-P 2 (1), and SUB-P 4 (2). In one embodiment, the number of reported sub-periods can be determined by the UE. The reported CSI consists of two phases, in which the UE reports the selected number of sub-periods in the first phase.

[0040] In one example, the sub-cycle CQI is reported by the UE via signaling the quantization difference from the full-cycle CQI. In another example, the sub-cycle RI is reported by the UE via signaling the difference from the full-cycle RI. In yet another example, the sub-cycle PMI shares the same basis vector as the full-cycle PMI. The coefficients of the sub-cycle PMI are reported by sending the quantized amplitude and phase difference from the coefficients of the full-cycle PMI.

[0041] In one example, for semi-persistent CSI reporting on PUSCH, the CSI calculation period configuration can be updated by activating DCI scrambled with SP-CSI-RNTI, for example, the number of time slots. In another example, for semi-persistent CSI reporting on PUCCH, the CSI calculation period configuration can be updated by activating a command, for example, the number of time slots. In yet another example, for aperiodic CSI reporting, the CSI calculation period configuration can be updated by triggering DCI, for example, the number of time slots.

[0042] Figure 8 This is a flowchart of a method for using a novel application of CSI reference time slots for measurement and calculation to support high-speed scenarios. In step 801, the UE receives Channel State Information Reference Signal (CSI-RS) configuration information from the base station (BS). In step 802, the UE determines a first CSI reference time slot for measurement and a second CSI reference time slot for calculation from the CSI-RS configuration information. In the time domain, the second CSI reference time slot occurs after the first CSI reference time slot. In step 803, the UE measures the CSI reference signal (CSI-RS) of the downlink channel received before the first CSI reference time slot for measurement. In step 804, the UE calculates the CSI of the downlink channel based on the second CSI reference time slot for calculation. The UE estimates and predicts the CSI of the downlink channel from the beginning of the second CSI reference time slot for calculation.

[0043] Figure 9 This is a flowchart of a method for configuring a CSI calculation period to support high-speed scenarios based on a novel aspect. In step 901, the UE receives Channel State Information Reference Signal (CSI-RS) configuration information from the base station (gNB). The CSI-RS configuration includes CSI-RS resources and a CSI calculation period, having one or more non-overlapping sub-periods within the CSI calculation period in the time domain. In step 902, the UE measures multiple timings of the CSI-RS of the downlink channel received through the configured CSI-RS resources. In step 903, the UE uses the timing correlation of the multiple CSI-RS timings to estimate the CSI of the downlink channel within the CSI calculation period. In step 904, the UE reports the estimated downlink channel CSI to the gNB and reports the estimated CSI according to the configured CSI calculation period.

[0044] Although the invention has been described in conjunction with certain specific embodiments for illustrative purposes, the invention is not limited thereto. Therefore, various modifications, alterations, and combinations of features of the described embodiments can be implemented without departing from the scope of the invention as set forth in the claims.

Claims

1. A method for measuring and calculating channel state information, comprising: User equipment (UE) receives channel state information (CSI) configuration information from base station (BS); The first Channel State Information (CSI) reference time slot for measurement and the second CSI reference time slot for calculation are determined based on the CSI configuration information, wherein the second CSI reference time slot appears after the first CSI reference time slot in the time domain; Measure the CSI-RS of the downlink channel received before the first CSI reference time slot used for measurement; as well as The CSI-RS of the downlink channel is calculated based on the second CSI reference time slot used for calculation, wherein the UE estimates and predicts the CSI of the downlink channel starting from the second CSI reference time slot used for calculation.

2. The channel state information measurement and calculation method according to claim 1, characterized in that, The UE is configured to report the CSI in the CSI reporting slot.

3. The channel state information measurement and calculation method according to claim 2, characterized in that, The first CSI reference time slot used for measurement appears at an offset prior to the CSI reporting time slot.

4. The channel state information measurement and calculation method according to claim 2, characterized in that, The second CSI reference time slot used for calculation occurs at an offset after the CSI reporting time slot.

5. The method for measuring and calculating channel state information according to claim 1, characterized in that, The UE reports the CSI of the downlink channel to the BS, including at least one of the rank indicator, precoding matrix indicator, and channel quality indicator.

6. The channel state information measurement and calculation method according to claim 1, characterized in that, The UE is configured with multiple CSI-RS times prior to the first CSI reference time slot used for CSI measurement.

7. The channel state information measurement and calculation method according to claim 6, characterized in that, The UE uses the timing correlation of the multiple CSI-RS timings to estimate and predict the CSI of the downlink channel.

8. The method for measuring and calculating channel state information according to claim 1, characterized in that, The UE is configured with a calculation period for calculating the CSI of the downlink channel during the calculation period.

9. The channel state information measurement and calculation method according to claim 8, characterized in that, The calculation cycle also includes multiple sub-cycles within the calculation cycle.

10. The method for measuring and calculating channel state information according to claim 9, characterized in that, The calculated CSI includes the sub-cycle-CSI and the full-cycle-CSI for the downlink channel.

11. A user equipment (UE) for measuring and calculating channel state information, comprising: The receiver receives Channel State Information (CSI) configuration information from the base station (BS); The control circuit determines a first channel state information (CSI) reference time slot for measurement and a second channel state information (CSI) reference time slot for calculation based on the CSI configuration information, wherein the second channel state information (CSI) reference time slot appears in the time domain after the first channel state information (CSI) reference time slot; The measurement circuit measures the CSI of the downlink channel received before the first Channel State Information (CSI) reference time slot used for measurement; and The CSI processing circuit calculates the CSI-RS of the downlink channel based on the second channel state information (CSI) reference time slot used for calculation, wherein the UE estimates and predicts the CSI of the downlink channel at a time starting from the second channel state information (CSI) reference time slot used for calculation.

12. The UE for measuring and calculating channel state information according to claim 11, characterized in that, The UE is configured to report the CSI in the CSI reporting slot.

13. The UE for measuring and calculating channel state information according to claim 12, characterized in that, The first Channel State Information (CSI) reference slot used for measurement appears at an offset prior to the CSI reporting slot.

14. The UE for measuring and calculating channel state information according to claim 12, characterized in that, The second channel state information (CSI) reference slot used for calculation occurs at an offset after the CSI reporting slot.

15. The UE for measuring and calculating channel state information according to claim 11, characterized in that, The UE reports to the BS the CSI of the downlink channel, including at least one of the rank indicator, precoding matrix indicator, and channel quality indicator.

16. The UE for measuring and calculating channel state information according to claim 11, characterized in that, The UE is configured with multiple CSI-RS timings prior to the first Channel State Information (CSI) reference time slot used for CSI measurement.

17. The UE for measuring and calculating channel state information according to claim 16, characterized in that, The UE uses the timing correlation of the multiple CSI-RS timings to estimate and predict the CSI of the downlink channel.

18. The UE for measuring and calculating channel state information according to claim 11, characterized in that, The UE is configured with a calculation period during which it calculates the CSI of the downlink channel.

19. The UE for measuring and calculating channel state information according to claim 18, characterized in that, The calculation cycle also includes multiple sub-cycles within the calculation cycle.

20. The UE for measuring and calculating channel state information according to claim 19, characterized in that, The calculated CSI includes the sub-cycle-CSI and the full-cycle-CSI for the downlink channel.

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