Patent Application
20240031081
The present disclosure relates to timing offset communication.
New Radio uses CP-OFDM (Cyclic Prefix Orthogonal Frequency Division Multiplexing) in both downlink (DL) (i.e., from a network node, gNB, or base station, to a user equipment or UE) and uplink (UL) (i.e., from UE to gNB). Discrete Fourier Trandform spread OFDM is also supported in the uplink. In the time domain, NR downlink and uplink are organized into equally sized subframes of 1 ms each. A subframe is further divided into multiple slots of equal duration. The slot length depends on subcarrier spacing. For subcarrier spacing of Δf=15 kHz, there is only one slot per subframe, and each slot consists of 14 OFDM symbols.
Data scheduling in NR is typically in slot basis, an example is shown in
Different subcarrier spacing values are supported in NR. The supported subcarrier spacing values (also referred to as different numerologies) are given by Δf=(15×2μ) kHz where μ∈{0, 1, 2, 3, 4}. Δf=15 kHz is the basic subcarrier spacing. The slot durations at different subcarrier spacings is given by
In the frequency domain, a system bandwidth is divided into resource blocks (RBs), each corresponds to 12 contiguous subcarriers. The RBs are numbered starting with 0 from one end of the system bandwidth. The basic NR physical time-frequency resource grid is illustrated in
Downlink (DL) and uplink (UL) data transmissions can be either dynamically or semi-persistently scheduled by a gNB. In case of dynamic scheduling, the gNB may transmit in a downlink slot downlink control information (DCI) to a UE on PDCCH (Physical Downlink Control Channel) about data carried on a physical downlink shared channel (PDSCH) to the UE and/or data on a physical uplink shared channel (PUSCH) to be transmitted by the UE. In case of semi-persistent scheduling, periodic data transmission in certain slots can be configured and activated/deactivated.
For each transport block data transmitted over PDSCH, a HARQ ACK is sent in a UL physical uplink control channel (PUCCH) on whether it is decoded successfully or not. An ACK is sent if it is decoded successfully and a NACK is sent otherwise.
PUCCH can also carry other UL control information (UCI) such as scheduling request (SR) and DL channel state information (CSI).
There are three DCI formats defined for scheduling PDSCH in NR, i.e., DCI format 1_0 and DCI format 1_1 which were introduced in NR Rel-15, and DCI format 1_2 which was introduced in NR Rel-16. DCI format 1_0 has a smaller size than DCI 1_1 and can be used when a UE is not fully connected to the network while DCI format 1_1 can be used for scheduling MIMO (Multiple-Input-Multiple-Output) transmissions with multiple MIMO layers.
In NR Rel-16, DCI format 1_2 was introduced for downlink scheduling. One of the main motivations for having the new DCI format is to be able to configure a very small DCI size which can provide some reliability improvement without losing much flexibility. The main design target of the new DCI format is thus to have DCI with configurable sizes for some fields with a minimum DCI size targeting a reduction of 10-16 bits relative to Rel-15 DCI format 1_0.
NR HARQ ACK/NACK Feedback Over PUCCH
When receiving a PDSCH in the downlink from a serving gNB at slot n, a UE feeds back a HARQ ACK at slot n+k over a Physical Uplink Control Channel (PUCCH) resource in the uplink to the gNB if the PDSCH is decoded successfully, otherwise, the UE sends a HARQ ACK/NACK at slot n+k to the gNB to indicate that the PDSCH is not decoded successfully. If two transport blocks (TBs) are carried by the PDSCH, then a HARQ ACK/NACK is reported for each TB.
For DCI format 1_0, k is indicated by a 3-bit PDSCH-to-HARQ-timing-indicator field. For DCI formats 1_1 and 1_2, k is indicated either by a 0-3 bit PDSCH-to-HARQ-timing-indicator field, if present, or by higher layer configuration through Radio Resource Control (RRC) signaling. Separate RRC configuration of PDSCH to HARQ-Ack timing are used for DCI formats 1_1 and 1_2.
For DCI format 1_1, if code block group (CBG) transmission is configured, a HARQ ACK/NACK for each CBG in a TB is reported instead.
In case of carrier aggregation (CA) with multiple carriers and/or Time Division Duplexing operation, multiple aggregated HARQ ACK/NACK bits need to be sent in a single PUCCH.
In NR, up to four PUCCH resource sets can be configured to a UE. A PUCCH resource set with pucch-ResourceSetId=0 can have up to 32 PUCCH resources while for PUCCH resource sets with pucch-ResourceSetId=1 to 3, each set can have up to 8 PUCCH resources. A UE determines the PUCCH resource set in a slot based on the number of aggregated UCI (Uplink Control Information) bits to be sent in the slot. The UCI bits consists of HARQ ACK/NACK, scheduling request (SR), and channel state information (CSI) bits.
A 3 bits PUCCH resource indicator (PRI) field in DCI maps to a PUCCH resource in a set of PUCCH resources with a maximum of eight PUCCH resources. For the first set of PUCCH resources with pucch-ResourceSetId=0 and when the number of PUCCH resources, RPUCCH, in the set is larger than eight, the UE determines a PUCCH resource with index rPUCCH, 0≤rPUCCH≤RPUCCH−1 for carrying HARQ-ACK information in response to detecting a last DCI format 1_0 or DCI format 1_1 in a PDCCH reception, among DCI formats 1_0 or DCI formats 1_1 the UE received with a value of the PDSCH-to-HARQ_feedback timing indicator field indicating a same slot for the PUCCH transmission, as
where NCCE,p is a number of CCEs in CORESET P of the PDCCH reception for the DCI format 1_0 or DCI format 1_1 as described in Subclause 10.1 of 3gpp TS38.213 v15.4.0, nCCE,p is the index of a first CCE for the PDCCH reception, and ΔPRI is a value of the PUCCH resource indicator field in the DCI format 1_0 or DCI format 1_1.
PUCCH Formats: Five PUCCH formats are defined in NR, i.e., PUCCH formats 0 to 4. UE transmits UCI in a PUCCH using
PUCCH formats 0 and 2 use one or two OFDM symbols while PUCCH formats 1, 3, and 4 can span from 4 to 14 symbols. Thus, PUCCH format 0 and 2 are referred to as short PUCCH while PUCCH formats 1, 3, and 4 as long PUCCH.
Short PUCCH formats: A PUCCH format 0 resource can be one or two OFDM symbols within a slot in time domain and one RB in frequency domain. UCI is used to select a cyclic shift of a computer-generated length 12 base sequence which is mapped to the RB. The starting symbol and the starting RB are configured by RRC. In case of 2 symbols are configured, the UCI bits are repeated in 2 consecutive symbols.
A PUCCH format 2 resource can be one or two OFDM symbols within a slot in time domain and one or more RB in frequency domain. UCI in PUCCH Format 2 is encoded with Reed-Muller (RM) codes (≤11 bits UCI+CRC) or Polar codes (>11 bit UCI+CRC) and scrambled. In case of 2 symbols are configured, UCI is encoded and mapped across two consecutive symbols.
Intra-slot frequency hopping (FH) may be enabled in case of 2 symbols are configured for PUCCH formats 0 and 2. If FH is enabled, the starting PRB in the second symbol is configured by RRC. Cyclic shift hopping is used when 2 symbols are configured such that different cyclic shifts are used in the 2 symbols.
Long PUCCH formats: A PUCCH format 1 resource is 4-14 symbols long and 1 PRB wide per hop. A computer-generated length 12 base sequence is modulated with UCI and weighted with time-domain OCC code. Frequency-hopping with one hop within the active UL BWP for the UE is supported and can be enabled/disabled by RRC. Base sequence hopping across hops is enabled in case of FH and across slots in case of no FH.
A PUCCH Format 3 resource is 4-14 symbols long and one or multiple PRB wide per hop. UCI in PUCCH Format 3 is encoded with RM (Reed-Muller) codes (511 bit UCI+CRC) or Polar codes (>11 bit UCI+CRC) and scrambled.
A PUCCH Format 4 resource is also 4-14 symbols long but 1 PRB wide per hop. It has a similar structure as PUCCH format 3 but can be used for multi-UE multiplexing.
Sub-slot based PUCCH transmission: In NR Rel-16, sub-slot based PUCCH transmission was introduced so that HARQ-Ack associated with different type of traffic can be multiplexed in a same UL slot, each transmitted in a different sub-slot. The sub-slot size can be higher layer configured to either 2 symbols or 7 symbols. In case of sub-slot configuration each with 2 symbols, there are 7 sub-slots in a slot. In case of sub-slot with 7 symbols, there are two sub-slots in a slot.
HARQ A/N enhancement for URLLC in NR Rel-16: In NR Rel 16, a higher priority may be assigned to PDSCHs carrying URLLC (Ultra-reliable Low latency) traffic and indicated in DCIs scheduling the PDSCHs. HARQ Ack/Nack information for PDSCHs with higher priority is transmitted separately from HARQ A/N information for other PDSCHs. This allows HARQ A/N for URLLC traffic be transmitted early in different PUCCH resources and more reliably.
Furthermore, in NR Rel-16, it has been agreed that at least one sub-slot configuration for PUCCH can be UE-specifically configured and that multiple HARQ Ack/Nack transmissions per slot are possible. The sub-slot configuration supports periodicities of 2 symbols (i.e., seven 2-symbol PUCCH occasions per slot) and 7 symbols (i.e., two 7-symbol PUCCH occasions per slot). One of the reasons for introducing these sub-slot configurations in NR Rel-16 is to enable the possibility for multiple opportunities of HARQ Ack/Nack transmissions within a slot without needing to configure several PUCCH resources. For example, in Rel-16, a UE running URLLC service may be configured with a possibility of receiving PDCCH in every second OFDM symbol e.g., symbol 0, 2, 4, . . . , 12 and be configured with a PUCCH resource with sub-slot configuration seven 2-symbol sub-slots within a slot for HARQ-ACK transmission also in every second symbol, e.g., 1, 3, . . . , 13. For a Rel-16 UE configured with sub-slots for PUCCH transmission, the PDSCH-to-HARQ feedback timing indicator field in DCI indicates the timing offset in terms of sub-slots instead of slots.
CSI framework in NR: In NR, a UE can be configured with multiple CSI reporting settings (each represented by a higher layer parameter CSI-ReportConfig with an associated identity ReportConfigID) and multiple CSI resource settings (each represented by a higher layer parameter CSI-ResourceConfig with an associated identity CSI-ResourceConfigId). Each CSI resource setting can contain multiple CSI resource sets (each represented by a higher layer parameter NZP-CSI-RS-ResourceSet with an associated identity NZP-CSI-RS-ResourceSetd for channel measurement or by a higher layer parameter CSI-IM-ResourceSetwith an associated identity CSI-IM-ResourceSetId forinterference measurement), and each NZP CSI-RS resource set for channel measurement can contain up to 8 NZP CSI-RS resources. For each CSI reporting setting, a UE feeds back a set of CSIs, which may include one or more of a CRI (CSI-RS resource indicator), a RI, a PMI, and a CQI per CW, depending on the configured report quantity.
Each Reporting Setting CSI-ReportConfig is associated with a single downlink BWP (indicated by higher layer parameter BWP-Id) given in the associated CSI-ResourceConfig for channel measurement and contains the parameter(s) for one CSI reporting band.
In each CSI reporting setting, it contains at least the following information:
For periodic and semi-static CSI reporting, only one NZP CSI-RS resource set can be configured for channel measurement and one CSI-IM resource set for interference measurement. For aperiodic CSI reporting, a CSI resource setting for channel measurement can contain more than one NZP CSI-RS resource set for channel measurement. If the CSI resource setting for channel measurement contains multiple NZP CSI-RS resource sets for aperiodic CSI report, only one NZP CSI-RS resource set can be selected and indicated to a UE. For aperiodic CSI reporting, a list of trigger states is configured (given by the higher layer parameters CSI-AperiodicTriggerStateList). Each trigger state in CSI-AperiodicTriggerStateList contains a list of associated CSI-ReportConfigs indicating the Resource Set IDs for channel and optionally for interference. For a UE configured with the higher layer parameter CSI-AperiodicTriggerStateList, if a Resource Setting linked to a CSI-ReportConfig has multiple aperiodic resource sets, only one of the aperiodic CSI-RS resource sets from the Resource Setting is associated with the trigger state, and the UE is higher layer configured per trigger state per Resource Setting to select the one NZP CSI-RS resource set from the Resource Setting.
When more than one NZP CSI-RS resources are contained in the selected NZP CSI-RS resource set for channel measurement, a CSI-RS resource indicator (CRI) is reported by the UE to indicate to the gNB about the one selected NZP CSI-RS resource in the resource set, together with RI, PMI and CQI associated with the selected NZP CSI-RS resource. This type of CSI assumes that a PDSCH is transmitted from a single transmission point (TRP) and the CSI is also referred to as single TRP CSI.
Aperiodic CSI feedback on PUCCH: In current NR specifications, aperiodic CSI feedback can only be carried via PUSCH. Furthermore, in current NR specifications, the aperiodic CSI feedback can only be trigged via uplink related DCI (i.e., DCI formats 0_1 and 0_2). However, this is not flexible in a scenario that is downlink heavy where the gNB would schedule the UE with PDSCH via downlink related DCI (i.e., DCI formats 1_1 and 1_2) more often than scheduling the UE with PUSCH via uplink related DCI. To improve network scheduling flexibility, it is beneficial to support triggering of aperiodic CSI via downlink related DCI. In this case, the aperiodic CSI will be carried on PUCCH.
In United States Patent Application Publication 2020/0295903 “PUCCH RESOURCE INDICATION FOR CSI AND HARQ FEEDBACK” (hereinafter referred to as [1]), a solution is proposed where a CSI request field is introduced in downlink related DCI which would be used to trigger aperiodic CSI reports on PUCCH. Furthermore, the solution in [1] proposes to reuse the existing PUCCH resource indication field in downlink related DCI to indicate the PUCCH resource for aperiodic CSI feedback. Depending on if the downlink related DCI carries a downlink grant for PDSCH and/or a CSI request, the PUCCH resource indication field can be interpreted differently according to the solution in [1].
In [1], one solution is proposed where the Aperiodic CSI and the HARQ-ACK corresponding to the PDSCH being scheduled by the downlink related DCI are multiplexed and sent on the same PUCCH resource. To address the cases where the PDSCH processing time and the processing time for aperiodic CSI are different, another solution is proposed in [1] where the Aperiodic CSI and HARQ-ACK corresponding to the PDSCH being scheduled by the downlink related DCI are transmitted in different slots.
In some disclosures, methods on using uplink DCI to indicate whether A-CSI is on PUCCH or PUSCH, on support of specific PUCCH format, i.e., format 2, 3, 4, on A-CSI on PUCCH handling when colliding with other CSI on the same slot are provided.
In NR, the timing offset for a HARQ ACK/NACK is given by the PDSCH-to-HARQ-timing-indicator field in downlink related DCI. However, when aperiodic CSI is triggered via downlink related DCI (e.g., DCI formats 1_1 and 1_2), how to indicate the timing offset for a aperiodic CSI report is not specified. Although [1] proposes aperiodic CSI and HARQ-ACK/NACK corresponding to the PDSCH being scheduled by the downlink related DCI being transmitted in different slots, [1] does not solve the problem how to indicate the timing offset of the aperiodic CSI report. Hence, it is an open problem how to indicate the timing offset of the aperiodic CSI report when such a report is triggered by downlink related DCI.
Systems and methods for timing determination for aperiodic Channel State Information (CSI) on Physical Uplink Control Channel (PUCCH) are provided. In some embodiments, a method performed by a wireless device for reporting channel state information includes one or more of: receiving a downlink related Downlink Control Information (DCI) triggering an aperiodic CSI; determining a timing offset for the aperiodic CSI to be reported on PUCCH; and reporting the aperiodic CSI on PUCCH based on the determined timing offset. In this way, efficient and low overhead signaling of timing offset of aperiodic CSI report is enabled.
In this disclosure, methods are proposed for indicating timing offset for an aperiodic CSI to be reported on PUCCH which is triggered via a downlink related DCI. The methods proposed include on or more of: indicating the timing of aperiodic CSI via the PDSCH-to-HARQ-timing-indicator field in downlink related DCI, indicating the timing of aperiodic CSI via higher layer configuration (e.g., RRC signaling), providing the timing of aperiodic CSI as part of a trigger state for CSI request field in the downlink related DCI, providing the timing of aperiodic CSI via a configured PUCCH resource with a periodicity and slot offset.
The benefits of the proposed methods include efficient and low overhead signaling of timing offset of aperiodic CSI report on PUCCH when such a report is triggered by downlink related DCI.
The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.
The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.
Radio Node: As used herein, a “radio node” is either a radio access node or a wireless communication device.
Radio Access Node: As used herein, a “radio access node” or “radio network node” or “radio access network node” is any node in a Radio Access Network (RAN) of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), a relay node, a network node that implements part of the functionality of a base station or a network node that implements a gNB Distributed Unit (gNB-DU)) or a network node that implements part of the functionality of some other type of radio access node.
Core Network Node: As used herein, a “core network node” is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), or the like. Some other examples of a core network node include a node implementing a Access and Mobility Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), or the like.
Communication Device: As used herein, a “communication device” is any type of device that has access to an access network. Some examples of a communication device include, but are not limited to: mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or Personal Computer (PC). The communication device may be a portable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data via a wireless or wireline connection.
Wireless Communication Device: One type of communication device is a wireless communication device, which may be any type of wireless device that has access to (i.e., is served by) a wireless network (e.g., a cellular network). Some examples of a wireless communication device include, but are not limited to: a User Equipment device (UE) in a 3GPP network, a Machine Type Communication (MTC) device, and an Internet of Things (IoT) device. Such wireless communication devices may be, or may be integrated into, a mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or PC. The wireless communication device may be a portable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data via a wireless connection.
Network Node: As used herein, a “network node” is any node that is either part of the RAN or the core network of a cellular communications network/system.
Transmission/Reception Point (TRP): In some embodiments, a TRP may be either a network node, a radio head, a spatial relation, or a Transmission Configuration Indicator (TCI) state. A TRP may be represented by a spatial relation or a TCI state in some embodiments. In some embodiments, a TRP may be using multiple TCI states.
Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.
Note that, in the description herein, reference may be made to the term “cell”; however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.
The base stations 702 and the low power nodes 706 provide service to wireless communication devices 712-1 through 712-5 in the corresponding cells 704 and 708. The wireless communication devices 712-1 through 712-5 are generally referred to herein collectively as wireless communication devices 712 and individually as wireless communication device 712. In the following description, the wireless communication devices 712 are oftentimes UEs, but the present disclosure is not limited thereto.
In NR, the timing offset for a HARQ ACK/NACK is given by the PDSCH-to-HARQ-timing-indicator field in downlink related DCI. However, when aperiodic CSI is triggered via downlink related DCI (e.g., DCI formats 1_1 and 1_2), how to indicate the timing offset for a aperiodic CSI report is not specified. Although [1] proposes aperiodic CSI and HARQ-ACK/NACK corresponding to the PDSCH being scheduled by the downlink related DCI being transmitted in different slots, [1] does not solve the problem how to indicate the timing offset of the aperiodic CSI report. Hence, it is an open problem how to indicate the timing offset of the aperiodic CSI report when such a report is triggered by downlink related DCI.
Systems and methods for timing determination for aperiodic CSI on Physical Uplink Control Channel (PUCCH) are provided.
In some embodiments, a method performed by a wireless device for reporting channel state information includes one or more of: receiving (step 800) a downlink related Downlink Control Information (DCI) triggering an aperiodic CSI; determining (step 802) a timing offset for the aperiodic CSI to be reported on PUCCH; and reporting (step 804) the aperiodic CSI on PUCCH based on the determined timing offset. In this way, efficient and low overhead signaling of timing offset of aperiodic CSI report is enabled.
In some embodiments, a method performed by a base station for receiving channel conditions includes one or more of: transmitting (step 900) a downlink related Downlink Control Information, DCI, triggering an aperiodic Channel State Information, CSI; indicating (step 902) a timing offset for the aperiodic CSI to be reported on Physical Uplink Control Channel, PUCCH; and receiving (step 904) the aperiodic CSI on PUCCH based on the determined timing offset.
The benefits of the proposed methods include efficient and low overhead signaling of timing offset of aperiodic CSI report on PUCCH when such a report is triggered by downlink related DCI.
In one embodiment, the timing of aperiodic CSI report triggered via a downlink related DCI format is given by reusing the PDSCH-to-HARQ-timing-indicator field in DCI. Note that since this field already provides the timing of HARQ-ACK/NACK (i.e., PDSCH to HARQ-ACK/NACK timing), the solution in this embodiment essentially means that the timing of HARQ-ACK/NACK and the timing of aperiodic CSI report are provided by a single PDSCH-to-HARQ-timing-indicator field in DCI. However, a codepoint in the PDSCH-to-HARQ-timing-indicator field in DCI is interpreted differently when deriving the timing of an aperiodic CSI report and the timing of the HARQ-ACK/NACK.
An example is shown in
Table 1 shows an example mapping between the codepoints of PDSCH-to-HARQ_feedback timing indicator field to the timing of aperiodic CSI reporting on PUCCH. For instance, when the number of bits in PDSCH-to-HARQ_feedback timing indicator field is 3, a codepoint with value ‘010’ corresponds to a timing offset for aperiodic CSI reporting on PUCCH as follows:
In the above example embodiments, it is assumed that aperiodic CSI is transmitted by the UE in slot n+k over a PUCCH resource where n is the slot in which the UE received a PDSCH in the downlink and k is the timing offset for the aperiodic CSI report. Alternatively, the timing offset k may be configured by higher layers (e.g., RRC configuration).
In some embodiments, if the UE is configured for sub-slot based PUCCH transmission (for instance, via a higher layer parameter subslotLengthForPUlCCH-r16), the timing offset k for aperiodic CSI report on PUCCH is given in subslots where a subslot is defined by a PUCCH transmission that includes a number of symbols given by higher layer parameter subslotLengthForPUlCCH-r16.
In another embodiment, whether to use subslot based or slot based timing offset is independently configured for aperiodic CSI report on PUCCH and HARQ-ACK/NACK. In one example, the timing offset for aperiodic CSI report on PUCCH is given in slots while the timing offset for HARQ-ACK/NACK is given in subslots. In another example, the timing offsets for both aperiodic CSI report on PUCCH and HARQ-ACK/NACK are both given in subslots. In yet another example, the timing offsets for both aperiodic CSI report on PUCCH and HARQ-ACK/NACK are both given in slots.
In the discussion above, ‘slot’ and ‘sub-slot’ refers to those for uplink carrier. It is noted that if uplink and downlink carrier use different Subcarrier Spacing (SCS), a downlink slot (or DL subslot, if defined) has different duration than that of a uplink slot (or UL sub-slot).
In some further embodiments, the number of bits in PDSCH-to-HARQ_feedback timing indicator field is increased to a number higher than 3 bits (e.g., 5 bits) when this field is used to indicate the timings of both HARQ-ACK/NACK and aperiodic CSI reporting. The increase in the number of bits is motivated by the fact that the single field is used to indicate the two timings (i.e., HARQ-ACK/NACK timing and aperiodic CSI report timing). A larger number of bits in the PDSCH-to-HARQ_feedback timing indicator field helps maintain the granularity with which the timings of HARQ-ACK/NACK and aperiodic CSI reporting are indicated. For instance, a 5 bit PDSCH-to-HARQ_feedback timing indicator field allows 8 different timing values for HARQ-ACK/NACK to be flexibly combined with 4 different timing values for aperiodic CSI reporting (i.e., 8*4=32 combinations given by the 5 bits). In some embodiments, the condition for increasing the number of bits in the PDSCH-to-HARQ_feedback timing indicator field beyond 3 bits may be given by one or more of the following:
In another embodiment, a new field is introduced in DL related DCI to indicate the timing of aperiodic CSI reporting. This new field is different from the PDSCH-to-HARQ_feedback timing indicator field.
In this embodiment, the timing of aperiodic CSI report is given with respect to the timing of HARQ-ACK/NACK. As shown in
The signaling of k′ can also be combined with the method provided in embodiment 1. That is, the UE can be provided by a list/sequence of candidate k′ values in dl-DataToA-CSI-r17 in the case of DCI format 1_1 and/or a list/sequence of candidate k′ values in dl-DataToA-CSI-ForDCI-Format1-2-r17 in the case of DCI format 1_2. Then, one of the k′ values is indicated to the UE via a codepoint of PDSCH-to-HARQ_feedback timing indicator field or a similar field in DCI to indicate the timing of the aperiodic CSI on PUCCH.
In some cases, the UE may be able to report the aperiodic CSI report on PUCCH before transmitting the HARQ-ACK/NACK feedback. To cover these cases, in one specific embodiment, the value range for k′ can include negative integers.
In some other cases, when the processing time to compute aperiodic CSI is similar to the PDSCH processing time, it may be possible for the UE to multiplex HARQ-ACK/NACK and aperiodic CSI on the same PUCCH resource. To cover these cases, in one specific embodiment, a value of 0 is included in the value range for k′.
In some embodiments, if the UE is configured for sub-slot based PUCCH transmission (for instance, via a higher layer parameter subslotLengthForPUCCH-r16), the timing offset k for aperiodic CSI report on PUCCH is given in subslots as well, even though the PUCCH resources for A-CSI transmission can be defined for a slot. In this case, ‘n’ refers to the sub-slot that PDSCH transmission ended, and sub-slot (n+k+k) is where A-CSI transmission starts.
In another embodiment, whether to use subslot based or slot based timing offset is independently configured for aperiodic CSI report on PUCCH and HARQ-ACK/NACK. In one example, the timing offset for aperiodic CSI report on PUCCH is given in slots while the timing offset for HARQ-ACK/NACK is given in subslots. When A-CSI and HARQ-ACK uses different uplink time units (slot vs sub-slot), then timing indices n, k, and k′ are all converted into the unit used by A-CSI for the purpose of determining the start of A-CSI transmission.
In this embodiment, the timing of aperiodic CSI report is given with respect to the timing of PDSCH. As shown in
The signaling of k′ can also be combined with the method provided in embodiment 1. That is, the UE can be provided by a list/sequence of candidate k′ values in dl-DataToA-CSI-r17 in the case of DCI format 1_1 and/or a list/sequence of candidate k′ values in dl-DataToA-CSI-ForDCI-Format1-2-r17 in the case of DCI format 1_2. Then, one of the k′ values is indicated to the UE via a codepoint of PDSCH-to-HARQ_feedback timing indicator field or a similar field in DCI to indicate the timing of the aperiodic CSI on PUCCH.
In this embodiment, the timing of aperiodic CSI report is given with respect to the timing of PDCCH. As shown in
The signaling of k′ can also be combined with the method provided in embodiment 1. That is, the UE can be provided by a list/sequence of candidate k′ values in dl-DataToA-CSI-r17 in the case of DCI format 1_1 and/or a list/sequence of candidate k′ values in dl-DataToA-CSI-ForDCI-Format1-2-r17 in the case of DCI format 1_2. Then, one of the k′ values is indicated to the UE via a codepoint of PDSCH-to-HARQ_feedback timing indicator field or a similar field in DCI to indicate the timing of the aperiodic CSI on PUCCH.
In another embodiment, a new bit field in DCI may be added to indicate the time offset between a PDCCH carrying the DCI with A-CSI request (or the PDSCH scheduled by the DCI, or the HARQ A/N associated with the PDSCH) and the PUCCH carrying the corresponding A-CSI report. The presence or absence of the bit field in a DCI format may be configurable by the higher layers.
In another embodiment, the timing of Aperiodic CSI report is provided as part of the trigger state for CSI request field in downlink related DCI. An example is shown in
As shown in
In this embodiment, a different timing value (i.e., a different DL-timeToA-CSI) may be triggered depending on which CSI-Report configuration (i.e., which CSI-AssociatedReportConfigInfoDownlink) is triggered by downlink related DCI.
In some embodiments, the DL-timeToA-CSI may be an optional field in CSI-AssociatedReportConfigInfoDownlink.
In this embodiment, a PUCCH resource with a periodicity and slot offset is configured for aperiodic CSI reporting, but aperiodic CSI is only transmitted on the configured PUCCH resource when triggered via a downlink related DCI.
In one embodiment, when a downlink related DCI triggers an aperiodic CSI report, the aperiodic CSI is reported on the first instance of the periodic PUCCH resource.
In another embodiment, when a downlink related DCI triggers an aperiodic CSI report, the aperiodic CSI is reported on the first instance of the periodic PUCCH resource after a predefined time k′.
In yet another embodiment, when a downlink related DCI triggers an aperiodic CSI report, the aperiodic CSI is reported on the first instance of the periodic PUCCH resource that happens after time k′, where k′ is indicated to the UE using any of the embodiments 1-5.
In one example of embodiment 6, time k′ is the number of slots relative to the slot in which the UE transmits HARQ-ACK/NACK as shown in
In another example of embodiment 6, time k′ is the number of slots relative to the slot in which the UE receives the PDSCH as shown in
In yet another example of embodiment 6, time k′ is the number of slots relative to the slot in which the UE receives the PDCCH that carries the DL related DCI which triggers the aperiodic CSI report as shown in
The above embodiments can be combined with event driven aperiodic CSI on PUCCH. For instance, the timing of Aperiodic CSI on PUCCH may be provided by the Embodiments covered above. However, in some embodiments, whether the UE transmits the aperiodic CSI on PUCCH may depend on the UE's unsuccessful decoding the PDSCH. If the UE sends a HARQ-NACK, then the aperiodic CSI is transmitted on PUCCH. Otherwise, the aperiodic CSI is not transmitted on PUCCH.
In this embodiment, the time k′ is from the end of symbol for last CSI measurement resource defined for A-CSI.
For periodic CSI-RS and CSI-IM, the last measurement resource for CSI could be defined as the smallest n′ such as a CSI-RS or CSI-IM is present in slot n−n′, where n is the slot where the PDCCH that triggered the A-CSI on PUCCH was detected. In some embodiments, the n′ is further restricted by CSI processing times in UE such that n′ must be greater than a certain value Z. The value Z may be different depending on if the measurement resource for CSI is a CSI-RS or a CSI-IM, e.g., a larger value may hold for CSI-RS since UE need to perform channel estimation which typically is more complex that performing interference estimation. The measurement resource for CSI for A-CSI may consist of one or more occurrences of CSI-RS and/or CSI-IM.
One example of this embodiment for periodic CSI-RS and CSI-RS is illustrated in
As illustrated in
For aperiodic CSI-RS and CSI-IM the PDCCH that triggers A-CSI also indicates measurement resources for CSI (CSI MRs). The value k′ may be from the end of last symbol of the last indicated measurement resource for CSI as illustrated in
As used herein, a “virtualized” radio access node is an implementation of the radio access node 2000 in which at least a portion of the functionality of the radio access node 2000 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the radio access node 2000 may include the control system 2002 and/or the one or more radio units 2010, as described above. The control system 2002 may be connected to the radio unit(s) 2010 via, for example, an optical cable or the like. The radio access node 2000 includes one or more processing nodes 2100 coupled to or included as part of a network(s) 2102. If present, the control system 2002 or the radio unit(s) are connected to the processing node(s) 2100 via the network 2102. Each processing node 2100 includes one or more processors 2104 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 2106, and a network interface 2108.
In this example, functions 2110 of the radio access node 2000 described herein are implemented at the one or more processing nodes 2100 or distributed across the one or more processing nodes 2100 and the control system 2002 and/or the radio unit(s) 2010 in any desired manner. In some particular embodiments, some or all of the functions 2110 of the radio access node 2000 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 2100. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 2100 and the control system 2002 is used in order to carry out at least some of the desired functions 2110. Notably, in some embodiments, the control system 2002 may not be included, in which case the radio unit(s) 2010 communicate directly with the processing node(s) 2100 via an appropriate network interface(s).
In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of radio access node 2000 or a node (e.g., a processing node 2100) implementing one or more of the functions 2110 of the radio access node 2000 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).
In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the wireless communication device 2300 according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).
With reference to
The telecommunication network 2500 is itself connected to a host computer 2516, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server, or as processing resources in a server farm. The host computer 2516 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 2518 and 2520 between the telecommunication network 2500 and the host computer 2516 may extend directly from the core network 2504 to the host computer 2516 or may go via an optional intermediate network 2522. The intermediate network 2522 may be one of, or a combination of more than one of, a public, private, or hosted network; the intermediate network 2522, if any, may be a backbone network or the Internet; in particular, the intermediate network 2522 may comprise two or more sub-networks (not shown).
The communication system of
Example implementations, in accordance with an embodiment, of the UE, base station, and host computer discussed in the preceding paragraphs will now be described with reference to
The communication system 2600 further includes a base station 2618 provided in a telecommunication system and comprising hardware 2620 enabling it to communicate with the host computer 2602 and with the UE 2614. The hardware 2620 may include a communication interface 2622 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 2600, as well as a radio interface 2624 for setting up and maintaining at least a wireless connection 2626 with the UE 2614 located in a coverage area (not shown in
The communication system 2600 further includes the UE 2614 already referred to. The UE's 2614 hardware 2634 may include a radio interface 2636 configured to set up and maintain a wireless connection 2626 with a base station serving a coverage area in which the UE 2614 is currently located. The hardware 2634 of the UE 2614 further includes processing circuitry 2638, which may comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The UE 2614 further comprises software 2640, which is stored in or accessible by the UE 2614 and executable by the processing circuitry 2638. The software 2640 includes a client application 2642. The client application 2642 may be operable to provide a service to a human or non-human user via the UE 2614, with the support of the host computer 2602. In the host computer 2602, the executing host application 2612 may communicate with the executing client application 2642 via the OTT connection 2616 terminating at the UE 2614 and the host computer 2602. In providing the service to the user, the client application 2642 may receive request data from the host application 2612 and provide user data in response to the request data. The OTT connection 2616 may transfer both the request data and the user data. The client application 2642 may interact with the user to generate the user data that it provides.
It is noted that the host computer 2602, the base station 2618, and the UE 2614 illustrated in
In
The wireless connection 2626 between the UE 2614 and the base station 2618 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 2614 using the OTT connection 2616, in which the wireless connection 2626 forms the last segment. More precisely, the teachings of these embodiments may improve the e.g., data rate, latency, power consumption, etc. and thereby provide benefits such as e.g., reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc.
A measurement procedure may be provided for the purpose of monitoring data rate, latency, and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 2616 between the host computer 2602 and the UE 2614, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 2616 may be implemented in the software 2610 and the hardware 2604 of the host computer 2602 or in the software 2640 and the hardware 2634 of the UE 2614, or both. In some embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 2616 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which the software 2610, 2640 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 2616 may include message format, retransmission settings, preferred routing, etc.; the reconfiguring need not affect the base station 2618, and it may be unknown or imperceptible to the base station 2618. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer's 2602 measurements of throughput, propagation times, latency, and the like. The measurements may be implemented in that the software 2610 and 2640 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 2616 while it monitors propagation times, errors, etc.
Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.
While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).
At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s).
Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/CN2020/119890 | Oct 2020 | WO | international |
This application claims the benefit of PCT patent application serial number PCT/CN2020/119890, filed Oct. 9, 2020, the disclosure of which is hereby incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/059255 | 10/8/2021 | WO |
