EP3925120A1

EP3925120A1 - Resource indication scheme for repeated transmissions

Info

Publication number: EP3925120A1
Application number: EP19915046.7A
Authority: EP
Inventors: Chunli Liang; Xianghui HAN; Peng Hao; Hao Wu
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2019-02-15
Filing date: 2019-02-15
Publication date: 2021-12-22
Also published as: EP3925120A4; CN113439400A; WO2020164102A1

Abstract

A method of wireless communication includes receiving, at a user device, indication information associated with repeatedly transmitting a channel, determining, based on the indication information, availability of one or more resources for performing repeated transmissions on the channel to a network device, upon detecting that the one or more resources is unavailable, scheduling transmissions performed on the channel in accordance with a next available resource, upon detecting that the one or more resources are available, scheduling transmissions performed on the channel in accordance with the one or more resources.

Description

RESOURCE INDICATION SCHEME FOR REPEATED TRANSMISSIONS

TECHNICAL FIELD

This patent document is directed generally to wireless communications.

BACKGROUND

Wireless communication technologies are moving the world toward an increasingly connected and networked society. The rapid growth of wireless communications and advances in technology has led to greater demand for capacity and connectivity. Other aspects, such as energy consumption, device cost, spectral efficiency, and latency are also important to meeting the needs of various communication scenarios. In comparison with the existing wireless networks, next generation systems and wireless communication techniques need to provide support for an increased number of users and services with different types of latency requirements, as well as support multiple repetitions of certain channels in an effort to meet enhanced coverage.
SUMMARY
This patent document describes, among other things, techniques for resource determination when certain channels are repeatedly transmitted from a user equipment (UE) device. In one example aspect, the repeatedly-transmitted channel can be configured to carry control information and/or user information. In one example aspect, the repeatedly-transmitted channels are downlink transmission from the network to a UE. In one example aspect, the repeated transmission on the shared channel can utilize transmission resources in the time domain, or in the frequency domain, or both.
In one example aspect, a method of wireless communication is disclosed. The method includes receiving, at a user device, an indication information associated with repeatedly performing transmissions on a channel. The method also includes determining, based on the indication information, availability of one or more resources for performing transmissions on the channel to a network device. Upon detecting that the one or more resources is unavailable, scheduling transmission performed on the channel in accordance with a next available resource. However, upon detecting that the one or more resources are available, scheduling transmissions performed on the channel in accordance with the one or more resources. The method also includes transmitting or receiving the repeatedly performing transmissions on the channel based on the configuration information.
In another example aspect, a wireless communication apparatus comprising at least one processor configured to implement the above-described method is disclosed.
In yet another aspect, a computer readable medium is disclosed. The computer readable medium stores processor-executable code for implementing the above-described method.
These, and other, aspects are described in the present document.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows an example of a wireless communication network.
FIG. 2 shows an example of repeated transmissions on a channel.
FIGs. 3A-3D show different configurations of repeated transmissions for an example embodiment.
FIGs. 4A-4C show different configurations of repeated transmissions for another example embodiment.
FIGs. 5A-5D show different configurations of repeated transmissions for yet another example embodiment.
FIG. 6 is an example flowchart associated with performing repeated transmissions on a channel.
FIG. 7 is a block diagram of an example implementation of a wireless communication apparatus.

DETAILED DESCRIPTION

Section headings are used in the present document only to improve readability and do not limit scope of the disclosed embodiments and techniques in each section to only that section. Certain features are described using the example of 5G wireless protocol. However, applicability of the disclosed techniques is not limited to only 5G wireless systems.
Systems, methods, and apparatus disclosed in this patent document are related to determining how time and/or frequency resources are to be allocated for repeated transmissions on an uplink shared channel (e.g., the PUSCH channel) from a user equipment (UE) . The allocated resources are determined based on indication parameters received from a base station. The disclosed technology has the advantage of being flexible in scheduling different variations of repeatedly transmitting the channel, which can be beneficial for services having low latency requirements. In contrast to conventional systems, the repeatedly-transmitted PUSCH channel can be sent in a single time slot or over multiple time slots. Furthermore, when transmitted over multiple time slots, the transmissions on the PUSCH channel can start at any suitable symbol in a time slot. Although the discussions herein are illustrated from the perspective of performing repeated transmissions “on the channel, ” this can be generally synonymous to performing repeated transmissions “of the channel. ” Although the present patent document is discussed with examples of PUSCH channel, the disclosed methods to determine the time domain resources for repeated transmissions are also applicable to channels other than PUSCH, e.g. PDCCH, PDSCH, PUCCH, PRACH.
FIG. 1 shows an example wireless communications network 100. The network 100 includes a base station BS 102 and multiple user devices (or, UEs) 106 being able to communicate with each other over a transmission medium 104. The transmissions from the devices 106 to the BS 102 are generally called uplink or upstream transmissions. The transmissions from the BS 102 to the devices 106 are generally called downlink or downstream transmissions. For example, the base station can send an uplink grant (UL grant) to devices 106. The UL grant (e.g., authorization information) is configured to schedule user devices 106 to perform a physical uplink shared channel (PUSCH) transmission. The PUSCH of a user device 106 occupies a corresponding time slot. The respective PUSCH transmissions associated with two or more user devices 106 may overlap with one another in the frequency domain. The overlap can be a partial overlap or complete overlap. The transmission medium 104 typically is wireless (air) medium. The BS 102 may also be communicatively coupled with other base stations or other equipment in the network via a backhaul or an access network connection 112.
FIG. 2 shows an example of repeated transmissions on a channel. In some embodiments, this channel can be the physical uplink shared channel (PUSCH) channel and the number of repeated transmissions on the PUSCH channel can be configured by radio resource control (RRC) signaling techniques. A UE can send the repeated transmissions across multiple time slots with at most one PUSCH transmission in a given time slot. Different PUSCH transmissions can have the same starting symbols across the multiple slots. In FIG. 2, PUSCH transmissions scheduled to be sent at time slot n, n+1, n+2 are shown, with each time slot divided into multiple mini-slots. In one example aspect (without limitation) , a time slot can be divided into fourteen (14) mini-slots for uplink symbols. Each mini-slot can correspond to a symbol. For example, mini-slot 1 corresponds to symbol 0, mini-slot 2 corresponds to symbol 1, min-slot 3 corresponds to symbol 2, .... mini-slot 14 corresponds to symbol 13. FIG. 2 demonstrates three PUSCH transmissions (or, synonymously three transmissions on the PUSCH channel) , with the PUSCH transmission repeated in slots n+1, n+2. The three transmissions (shown as grey shaded mini-slots) of the PUSCH channel start at symbol 10 in time slots n, n+1, n+2 at boundary positions 202, 206, 210 respectively. Irrespective of whether there is an uplink symbol at the beginning (e.g., symbol 0) of time slot n+1, the PUSCH transmission is repeated at symbol 10 of slots n+1 and n+2. The three transmissions on the PUSCH channel end at symbol 13 in time slots n, n+1, n+2 at boundary positions 204, 208, 212 respectively. Further, the three transmissions on the PUSCH channel have the same duration of 4 symbols each. Thus, FIG. 2 demonstrates that in current 5G systems, when the PUSCH channel is repeatedly transmitted, the same time domain resources (such as starting position of a PUSCH transmission, ending position of a PUSCH transmission, duration of a PUSCH transmission) are utilized across the repeated transmissions. This approach, however, can be detrimental for services with low latency requirements. Furthermore, the time/frequency resources utilized in the repeated transmission are the same. If the starting symbol (e.g., symbol 206) of the repeated transmission appears relatively late in the slot (e.g., near the end of slot n+1 or slot n+2) , the UE has to wait a long time before retransmitting a PUSCH channel. This can introduce unwanted delays. In the discussions herein, the slots are shown as being numbered from one. In alternate implementations, the slots can be numbered starting from zero (0) .
To solve the above-mentioned problems, and other problems, the present patent document discloses example embodiments below in connection with two candidate PUSCH transmission repetition schemes. According to the first scheme, the repeated transmissions on the PUSCH channel may be in the same time slot or in different time slots. This scheme is called mini-slot PUSCH repetition. According to the second scheme, a PUSCH transmission is allowed at most once if there is only one uplink period within a given time slot, and repeated PUSCH transmissions on different time slots are allowed to have different start symbols and durations. Here the UL period is the duration of a set of contiguous symbols within a slot for potential UL transmission as determined by the UE. If there are more than one uplink periods within a slot, one repeated transmission occurs within one UL period. This scheme is called multi-segments transmission. The patent document discloses how resources (also termed “resource elements” ) allocated for PUSCH transmissions can be determined or calculated. Let the total number of estimated PUSCH transmissions be denoted as N, and i denote the transmission count such that i=0, 1, 2, ... N-1. For example, the number N can be estimated by the base station. The patent document discloses determining at least the following resources: (i) a starting symbol (S _i) number of a PUSCH transmission in a time slot and (ii) a duration (L _i) of a PUSCH transmission in a time slot. Other indication parameters that can be determined include the starting symbol (S ₀) of the first PUSCH transmission and the total transmission duration (L) summed over individual transmission durations L _i of each PUSCH transmission, the starting symbol number (S _j) of a first transmission in a time slot j and a total transmission duration (L _j) summed over transmissions on the channel in time slot j. Herein, the total transmission duration (L) and the total transmission duration in time slot j (L _j) are defined in units of symbols, and the slot is counted such that j=0, 1, 2, ... N-1, where N is an integer. In some embodiments, the UE determines the resources to be allocated for PUSCH transmissions based on one or more of the above-mentioned parameters S _i, S _j, L _i, L _j, S ₀, and L. These parameters can be included in (or, based upon) one or more of the following: the higher layer configurations, the uplink grant information, slot configurations, or the SFI. That is, in some implementations, the PUSCH channel in this patent document can be a grant-based PUSCH. In some implementations, the PUSCH channel in this patent document can be a configured-grant PUSCH.
The resources can be in the time domain, in the frequency domain, or in both domains. For purposes of illustration, the example embodiments discussed herein are based on assuming the total number of symbols in a slot P=14 and a maximum number of three (3) PUSCH transmissions. As a result, the transmission count i takes on values 0, 1, 2. However, the values used in the discussions herein are for illustration only. In alternate embodiments, other values of these quantities can be chosen. Various features and examples of the above-described schemes now described using a number of example embodiments.
Example Embodiment 1: Determining resources based on parameters (S _i, L)
In some embodiments, the UE can determine resources for PUSCH transmissions based on the values for the tuple (S _i , L) . Table 1 below shows a few example values that the tuple can take. In some embodiments, the UE can determine resources for PUSCH transmissions based on a value which is a joint coding of the tuple (S _i , L) .
Table 1
FIGs. 3A-3D show different configurations of PUSCH transmissions for this example embodiment. Row index 1, row index 2, row index 3 in the above table correspond respectively to the configurations shown in FIGs. 3A, 3B, 3C. S ₀ indicates the starting symbol number for the first PUSCH transmission, S ₁ indicates the starting symbol number for the 2nd PUSCH transmission, S ₂ indicates the starting symbol number for the 3rd PUSCH transmission, and L indicates the total transmission duration summed over PUSCH transmissions. PUSCH transmissions are shown as grey shaded mini-slots in FIGs. 3A-3D. For example, in FIG. 3A, two PUSCH transmissions are scheduled starting at the symbol 10 and symbol 0 in time slot n and time slot n+1 respectively. In the first PUSCH transmission, four symbols (symbols 10 through 13) are transmitted in time slot n. In the second PUSCH transmission, eight symbols (symbols 0 through 7) are transmitted in time slot n+1. Because the total transmission duration measured across all transmissions L is 12, two PUSCH transmissions are sufficient and no transmission occurs in time slot n+2. This is shown by a dash in the table above and no shaded mini-slots in time slot n+2 in FIG. 3A. In some embodiments, if the starting symbol number at a time slot is an invalid value (e.g., a value larger than 13) , this can indicate that there is no PUSCH transmission in that slot. Thus, it can be appreciated that one advantage of the disclosed technology is that delays can be greatly reduced, e.g., when PUSCH transmissions are completed by slot n+1 in FIG. 3A, whereas PUSCH transmissions are completed at slot n+2 in FIG. 2.
In FIG. 3B, three PUSCH transmissions with a total transmission duration of 12 are scheduled starting at symbol 10, symbol 12, and symbol 0 in time slots n, n+1, n+2 respectively. In the embodiments shown in FIG. 3A and FIG. 3B, all the symbols in each time slot are available for PUSCH transmission. In these cases, the starting symbol of each transmission is the same as the indication information in the uplink grant integrated with higher layer configuration information.
FIG. 3C shows more than one PUSCH transmission scheduled in a time slot. For example, FIG. 3C shows two PUSCH transmissions in slot n+1 in addition to one PUSCH transmission in slot n. In some embodiments, the symbols in a time slot are not necessarily all uplink symbols. For example, FIG. 3C shows that in time slot n+1, symbols 0 through 2, and symbols 7 through 8, are downlink symbols (shown with hatched mini-slots) . These downlink symbols are interspersed with uplink symbols 3 through 6 in slot n+1. Thus, there is a plurality of discontinuous uplink symbols in n+1, and the symbols in slot n and n+2 are all uplinks. If S _j represents the first transmission in slot n+j, then the first PUSCH transmission is from symbol 10 to 13 in slot n, the second PUSCH transmission is from symbol 3 to 6 in slot n+1, and the third PUSCH transmission is from symbol 9 to 10 in slot n+2. In some embodiments, the starting symbol is not available due to changes or updates to the slot configuration or slot format indicator (SFI) , e.g., in scenarios where the starting symbol is located on a downlink symbol or flexible symbol, then the starting symbol of a PUSCH transmission is postponed to a next first available symbol. In some embodiments, the slot format indicator (SFI) information field included as part of a physical downlink control channel (PDCCH) provides indication of the symbol being, an uplink symbol, a downlink symbol, or an otherwise flexible symbol. In some embodiments, the SFI is dynamically indicated by the base station.
FIG. 3D shows a scenario in which PUSCH transmissions scheduled according to a (S _i , L) tuple, e.g., indicated in row index 4 of the above table, is changed when the SFI is dynamically updated. Row index 4 indicates that three PUSCH transmissions are scheduled to start at symbol 10, symbol 3, and symbol 2 in time slots n, n+1, and n+2 respectively. The first PUSCH transmission starts at symbol 10 in time slot n. However, because of dynamically-changing SFI, the UE modifies the above-mentioned transmission schedule. Specifically, in view of the SFI in time slot n+1 indicating that time slots 0 through 9 are downlink symbols, the UE transmits the second PUSCH transmission at the first available uplink symbol (e.g., symbol 10) in time slot n+1. In some embodiments, several symbols may need to be reserved as a guard gag for switching from downlink to uplink, i.e., the first available uplink symbol may be a symbol which is several symbols after the first uplink symbol. Accordingly, the transmission duration in time slot n+1 is four (4) symbols starting at symbol 10. Two (2) symbols starting at symbol 2 are scheduled in time slot n+2. The resulting schedule for PUSCH transmissions is shown in FIG. 3D.
In accordance with disclosed embodiments, the actual time domain resource for transmission of each repetition is determined based on the higher layer configuration information (e.g., configurations such as those listed exemplarily in Table 1) , row index (e.g., row index 1, 2, 3, or 4 of Table 1 storing various configurations) indicated in the uplink (UL) grant, and the SFI. In the discussions above with respect to Table 1, FIG. 3C and FIG. 3D are shown to have different higher layer configurations. However, the embodiments in FIG. 3C and FIG. 3D can share the same higher layer configuration and uplink grant but have different SFI. If the number of rows (e.g., higher layer configurations) in Table 1 increases, the bit field in the uplink grant to indicate the row index may increase accordingly. FIG. 3C can also correspond to the configuration with row index=2, but the SFI in FIG. 3C and FIG. 3D are different.
In some embodiments, the base station can specify a number of repeated PUSCH transmissions implementable (by the UE) in a high-level indication table. Based on the above high-level table, in some embodiments, the number of start symbol control fields can be determined according to the maximum number of repetitions supported, and therefore, the start symbols in some configurations are redundant. In some embodiments, to reduce the redundancy in the high-level indication table, one method is to configure different tables for different repetition times. For example, one table can be configured for transmissions with a repetition number of 2 and another table can be configured for transmissions with a repetition number of 4.
Example Embodiment 2: Determining resources based on parameters (S _i, L _i)
In some embodiments, the UE can determine resources for PUSCH transmissions based on the values for the tuple (S _i , L _i ) . Table 2 below shows a few example values that the tuple can take. In some embodiments, the UE can determine resources for PUSCH transmissions based on a value which is a joint coding of the tuple (S _i , L _i ) .
Table 2
FIGs. 4A-4C show different configurations of PUSCH transmissions for this example embodiment. Row index 1, row index 2, row index 3 correspond respectively to the configurations shown in FIGs. 4A, 4B, 4C. S ₀ indicates the starting symbol number for the first PUSCH transmission, S ₁ indicates the starting symbol number for the 2nd PUSCH transmission, and S ₂ indicates the starting symbol number for the 3rd PUSCH transmission. Additionally, L ₀ indicates the duration of the 1st PUSCH transmission, L ₁ indicates the duration of the 2nd PUSCH transmission, and L ₂ indicates the duration of the 3rd PUSCH transmission. PUSCH transmissions are shown as grey shaded mini-slots in FIGs. 4A-4C. For example, in FIG. 4A, three PUSCH transmissions are scheduled starting at symbol 2, symbol 5, and symbol 0 in time slots n, n+1, and n+2 respectively. In the first PUSCH transmission, ten symbols (e.g., symbols 2 through 11) are transmitted in time slot n. In the second PUSCH transmission, nine symbols (e.g., symbols 5 through 13) are transmitted in time slot n+1. In the third PUSCH transmission, four symbols (e.g., symbols 0 through 3) are transmitted in time slot n+2. In FIG. 4B, two PUSCH transmissions are scheduled starting at symbol 8 and symbol 2 in time slots n and n+1 respectively. FIG. 4C shows a slot structure with downlink symbols and dynamically changing the transmission schedule in view of dynamically changing SFI. For example, the SFI from the base station can indicate that symbols 0 through 2 and symbols 7 through 8 are downlink symbols. As a result, the UE schedules: (i) in time slot n, a first PUSCH transmission starting at symbol 8 for a duration of 4 symbols and (ii) in time slot n+1, a second PUSCH transmission at symbol 3 (the first available uplink symbol) for a duration of 4 symbols and a third PUSCH transmission at symbol 9 for a duration of 4 symbols.
Example embodiment 1 and example embodiment 2 can be configured differently. Although embodiment 2 can be more flexible because it specifies the duration of each PUSCH transmission, embodiment 2 can consume additional signaling overhead. However, when signaling overhead is an issue, embodiment 1 can consume lower signaling overhead than embodiment 2.
Example Embodiment 3: Determining resources based on parameters (S ₀ , L _i)
In some embodiments, the UE can determine resources for PUSCH transmissions based on the values for the tuple (S ₀ , L _i ) . Table 3 below shows a few example values that the tuple can take. In some embodiments, the UE can determine resources for PUSCH transmissions based on a value which is a joint coding of the tuple (S ₀ , L _i ) .
Table 3
S ₀ indicates the starting symbol number for the first PUSCH transmission, L ₀ indicates the duration of the 1st PUSCH transmission, L ₁ indicates the duration of the 2nd PUSCH transmission, and L ₂ indicates the duration of the 3rd PUSCH transmission.
When all symbols in the uplink slot are uplink symbols, and the indication parameters in the uplink grant control information received by the UE are, for example, indicated as row index 1 in the table, the UE may determine that the uplink grant control information schedules three PUSCH transmissions in three consecutive time slots. The UE schedules the first PUSCH transmission starting at symbol 10 and the number of transmitted symbols is 4. The UE schedules the second PUSCH transmission starting at symbol 0 and the number of transmitted symbols is 4. The UE schedules the third PUSCH transmission starting at symbol 0 and the number of transmitted symbols is 4.
Example Embodiment 4: Determining resources based on cross-slot transmission indicator
In some embodiments, the UE can determine resources for PUSCH transmissions based, at least in part, on a cross-slot transmission indicator. In some implementations, the indicator can be included along with the tuple (S ₀ , L) so that the resultant tuple is (S ₀ , L, cross-slot transmission indicator) . In some implementations, the indicator can be included along with the tuple (S ₀ , L _i) so that the resultant tuple is (S ₀ , L _i, cross-slot transmission indicator) . For the sake of simplicity in discussions, it is assumed that the transmission duration L _i for each PUSCH transmission is the same, e.g., 8 symbols. Hence, L ₀ = L ₁= L ₂ ... L _i-1 = 8. Table 4 below shows a few example values that the tuple (S ₀ , L _i, cross-slot transmission indicator) can take.
Table 4
S ₀ indicates the starting symbol number for the first PUSCH transmission, L _i indicates the duration of each PUSCH transmission, and the cross-slot transmission indicator can be a binary number (relative to the first PUSCH transmission) indicating whether or not to perform PUSCH transmissions across consecutive time slots. A “0” value in a field of the cross-slot indicator indicates that cross-slot transmission is disabled whereas a “1” indicates that a cross-slot transmission is enabled. If the maximum number of PUSCH transmissions N = 3, then a the cross-slot transmission indicator can be N-1 bits long. In the above table, N=3. As a result, the cross-slot transmission indicator is 2 bits long. From the left to the right, the first bit position of the cross-slot transmission indicator indicates whether a PUSCH transmission is to be scheduled in the next time slot with respect to the first PUSCH transmission, the 2nd bit position indicates whether a PUSCH transmission is to be scheduled in two time slots with respect to the first PUSCH transmission, and so on. FIGs. 5A-5D show different configurations of PUSCH transmissions for this example embodiment. Row index 1, row index 2, row index 3, row index 4 correspond respectively to the configurations shown in FIGs. 5A, 5B, 5C, 5D. In FIGs. 5A-5D the first PUSCH transmission is scheduled to occur at time slot n. Depending on the first bit of the cross-slot transmission indicator, the 2nd PUSCH transmission may (e.g., when the first bit is 1) or may not (e.g., when the first bit is 0) occur at time slot n+1. Similarly, depending on the second bit of the cross-slot transmission indicator, the 3rd PUSCH transmission may (e.g., when the second bit is 1) or may not (e.g., when the second bit is 0) occur at time slot n+1.
If the starting symbol number indicated by the base station as indication parameter included in the uplink grant control cannot be used for uplink transmission of the PUSCH, for example, when the symbol is a downlink symbol or a flexible symbol, the start symbol of the transmission defaults to the first valid uplink symbol that is available. That is, the UE schedules the start symbol as the first valid uplink symbol available for PUSCH transmission. In some embodiments, the starting symbol number and duration of a PUSCH transmission is the same across multiple repetitions of the PUSCH channel. In some embodiments, the resources can be based on another field indicating whether (or not) the cross-slot transmission (s) is/are related to the number of repeated transmissions of the PUSCH channel.
Example Embodiment 5: UE determines transmission block size (TBS)
In some embodiments, the base station sends an uplink grant to the UE, the UE determines a modulation and coding scheme (MCS) and time/frequency resources associated with PUSCH transmission (s) first, and then subsequently calculates the transport block size (TBS) of individual PUSCH transmissions based on the determined MCS and time/frequency resources.
In conventional systems, if repeated PUSCH transmissions are configured, the time/frequency resources in each time slot are the same every time across each repeated transmission. As a result, the TBS for each PUSCH transmission is the same.
In some implementations, the UE can determine the TBS as specified below:
Step 1: Determine the number of resource elements, wherein REs denote resource elements and N _RE denote the number of resource elements within a slot.
Step 2: Determine the intermediate number of information bits
Step 3: Determine the final number of information bits based on a pre-defined table.
The present patent document discloses details of Step 1. Specifically, the present patent document disclosed details of calculating N _RE. In some implementations, details of the other steps can be found in the technical specification (e.g., 38.214) for NR technology.
In Step 1, N _RE can be calculated as follows. First, the UE can determine the number of REs allocated for PUSCH within a PRB (N′ _RE) by:
Then, a number of resource elements allocated for the PUSCH transmission (denoted N _RE) can be calculated as:
N _RE=min (156, N′ _RE) ·n _PRB, where is the number of subcarriers in the frequency domain in a physical resource block, is the number of symbols allocated for the PUSCH transmission within a time slot, is the number of REs for DMRS per physical resource block (PRB) in a duration allocated for the PUSCH transmission, is an amount of overhead configured by one or more higher layer parameters, and n _PRB is the total number of allocated PRBs for the UE.
With respect to the above equation, the present patent document specifically discloses details related to the determination of the number of symbols allocated for PUSCH transmission across multiple time slots replacing with Thus,
According to the disclosed technology, can be different across multiple slots because the duration of individual PUSCH transmissions can be different across slots. Thus, the UE can determine the number of symbols for PUSCH allocation across multiple slots based on several implementation options. A few of them are discussed below:
Option 1: where L is the total number of symbols included across all PUSCH transmissions or L is the total number of symbols for data transmission included across all PUSCH transmissions; P is a semi-statically configured value or a predetermined fixed value. For example, P =14.
Option 2: number of available uplink data symbols among all PUSCH transmissions.
Option 3: is the number of available uplink data symbols of a predefined PUSCH transmission, where the predefined PUSCH transmission can be the first PUSCH transmission, or a PUSCH transmission with the maximum number of data symbols, or a PUSCH transmission with a maximum number of demodulation reference symbols (DMRS) .
Option 4: where L is the total number of symbols included in all PUSCH transmissions, N is the total number of PUSCH transmissions, and and are the floor and ceiling operations respectively.
Option 5: is the number of available uplink data symbols in each PUSCH transmission.
Option 6: The TBS can be related to the MCS as follows. If the MCS is greater than a certain MCS threshold, option 1 can be used to calculate otherwise option 2 can be used.
To illustrate options for determining the example discussed in FIG. 3B is considered. In FIG. 3B, three PUSCH transmissions are scheduled in slots n, n+1, n+2 with 4, 2, 6 symbols respectively. The total number of symbols summed over all PUSCH transmissions is 12 and the maximum number of symbols among all PUSCH transmissions is 6. The values of for these options are given below.
Option 1: P is assumed to be 14 in this example.
Option 2:
Option 3: If the predefined PUSCH is the first PUSCH transmission, If the predefined PUSCH is a PUSCH transmission with maximum number of data symbols,
Option 4:
Option 5: for the 1st, 2nd, 3rd PUSCH transmissions respectively.
Option 6: Assuming the predefined MCS threshold is 6, if the indicated MCS for PUSCH transmission is 4, option 2 is used and However, if the indicated MCS for PUSCH transmission is 10, option 1 is used and
The examples discussed herein are solely for illustration. In alternate embodiments, different formula or methods can be used to calculate the value of
Example Embodiment 6
In the current NR specification, low density parity check codes (LDPC) is adopted for uplink data transmission. Different redundant versions (RV) are also defined and a “Redundancy version” bit field is included in the uplink scheduling grant. For control information transmission, Polar is used as a channel coding scheme, and no redundant version is defined. On the other hand, A-CSI (one form of the uplink control information) transmission without UL-SCH can be enabled on PUSCH by setting the “UL-SCH indicator” control field to “0” in the DCI. In this case, there is UL-SCH on the PUSCH, but the “Redundancy version” bit field still exists in the uplink grant. This bit field is invalid for the A-CSI transmission on PUSCH without UL-SCH. Therefore, UE behavior can be specified in connection with handling the “Redundancy version” bit field.
“Redundancy version” bit field is not applicable for PUSCH without UL-SCH.
“Redundancy version” bit field (0, 1, or 2 bits) is not applicable for A-CSI transmission.
“Redundancy version” bit field is not applicable for PUSCH without UL-SCH if UL-SCH indicator is set to “0. ”
UE ignores “Redundancy version” bit field for PUSCH without UL-SCH.
Upon detection of a DCI format 0_1 with “UL-SCH indicator” set to “0” and with a non-zero “CSI request” where the associated “reportQuantity” in CSI-ReportConfig is not set to “none” for all CSI report (s) triggered by “CSI request” in this DCI format 0_1, the UE ignores bit field “Redundancy version” in this DCI and the UE can transmit the corresponding PUSCH as indicated by this DCI format 0_1.
Upon detection of a DCI format 0_1 with “UL-SCH indicator” set to “0” and with a non-zero “CSI request, ” the UE ignores bit field “Redundancy version” in this DCI.
Upon detection of a DCI format 0_1 with “UL-SCH indicator” set to “0, ” the UE ignores bit field “Redundancy version” in this DCI.
Example embodiment 7
In the current NR specification, there can be three cases possibly causing collision of grant free transmission and slot configuration or slot format indication (SFI) :
· Case 1: If a set of symbols of a slot is configured for grant-free PUSCH and the UE detects a DCI indicating that the UE is to receive CSI-RS or PDSCH in a subset of symbols from the set of symbols, the UE cancels the PUSCH transmission of the remaining symbols from the set of symbols, but does not expect to cancel the transmission in symbols from the subset of symbols within the PUSCH preparation time T _proc, 2.
· Case 2: If the UE is configured by higher layers to transmit PUSCH in the set of symbols of the slot, and if the UE detects an SFI-index field value in DCI format 2_0 indicating the set of symbols of the slot as downlink or flexible, the UE can cancel the PUSCH transmission (s) in the slot.
· Case 3: If a UE is configured by higher layers with parameter SlotFormatIndicator, but the UE does not detect a DCI format 2_0 providing a slot format for the slot, the UE does not transmit a configured PUSCH in the slot, starting from a symbol X that equals the number of symbols corresponding to the PUSCH preparation time N2 for the corresponding PUSCH timing capability after a last symbol of a CORESET where the UE is configured to monitor PDCCH for DCI format 2_0. The UE does not expect to cancel the transmission of the PUSCH starting before the symbol X.
To achieve high reliability of URLLC, PUSCH transmission with K times of repetitions can be a possible implementation. However, in view of the above-mentioned cases, a common consequence is that some of the transmission occasions for PUSCH transmission might be canceled due to collision with slot configuration or SFI. This implies that the K repetitions cannot be guaranteed since not all the transmission occasions (TO) are available for transmission and further enhancements can be considered.
Accordingly, in some implementations, it can be assumed that that the UE does not expect such collision to happen. If such collision indeed happens, one of the following options can be adopted as the UE behavior:
Option 1: Cancel the collided repetition, and the canceled repetition is not counted in the K repetitions. To ensure the K repetitions, the transmission can be postponed to the next available transmission occasion. In other words, the K repetitions are transmitted in continuous available occasions. The available occasion doesn’ t include a collided occasion.
Option 2: Cancel the collided symbols and the canceled symbols is not counted in the total number of symbols for all repetitions. To ensure the K repetitions with full length, the transmission can be postponed to the next available transmission symbols. In other words, the K repetitions are transmitted in continuous available symbols. The available symbols do not include a collided symbol.
Option 3: If only a portion of symbols collided for a repetition, the UE still transmits PUSCH in the remaining symbols in the repetition occasion. Or, the UE still transmits PUSCH in the remaining symbols in the repetition occasion if the number of remaining symbols is larger than a threshold T, e.g., T=2.
However, the collided repetition can be counted in the K repetitions. Or, the collided repetition is not counted in the K repetitions. Or, the collided symbols is counted in the total number of symbols for all repetitions.
Option 4: If the collision happens, the UE can transmit PUSCH on the collided symbols. In this case, UE can change the slot configuration or slot format indication.
FIG. 6 is an example flowchart showing steps of a process associated with performing repeated transmissions on a channel. The process may be performed, for example, a UE operating in a wireless network. At step 602, the process receives a configuration information (or, indication information) associated with performing repeated transmissions on a channel (e.g., a PUSCH channel) . At step 604, the process determines availability of one or more resources for performing repeated transmissions on the channel to a network device (e.g., a base station or another UE) , based on the configuration information. Upon detecting that the one or more resources is unavailable, the process schedules (step 606) transmissions performed on the channel in accordance with a next available resource. However, upon detecting that the one or more resources are available, the process schedules (step 608) transmissions performed on the channel in accordance with the one or more resources. At step 610, the process transmits or receives, (e.g., depending on whether the channel is PUSCH, PDCCH, PDSCH, PUCCH, PRACH, etc. ) the repeatedly performing transmissions on the channel based on the configuration information.
FIG. 7 depicts a block diagram representing an architecture of a communication apparatus such as a user equipment (UE) 700. A UE 700 can include one or multiple processor electronics 710 such as a microprocessor that implements one or more of the wireless techniques presented in this document. The UE 700 can include transmitter electronics 715 and receiver electronics 720 to send and/or receive wireless signals over one or more communication interfaces such as antenna 720. In some implementations, transmitter electronics 715 and receiver electronics 720 can be integrated into a single electronics transceiver unit or module. The UE 700 can include other communication interfaces for transmitting and receiving data. The UE 700 can include one or more memories 705 configured to store information such as data and/or instructions related to the methods disclosed herein. In some implementations, the processor electronics 710 can include at least a portion of the transceiver electronics 715. In some embodiments, at least some of the disclosed techniques, modules or functions are implemented using the UE 700.
It will be appreciated that the present document discloses techniques that can be embodied into wireless communication systems to enable the use of uplink grant control information from the base station to indicate configuration parameters to UEs for PUSCH transmissions from UEs. The final scheduling can depend on the configuration parameters and dynamically-updated SFI information. The disclosed techniques can be useful for determining time and/or frequency resources associated with scheduling PUSCH transmissions. Although the present patent document is discussed with examples of PUSCH, the disclosed methods to determine the time domain resources for repeated transmissions are also applicable to channels other than PUSCH, e.g. PDCCH, PDSCH, PUCCH, PRACH.
The disclosed and other embodiments, modules and the functional operations described in this document can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this document and their structural equivalents, or in combinations of one or more of them. The disclosed and other embodiments can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer readable medium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more them. The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to suitable receiver apparatus.
A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document) , in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code) . A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.
The processes and logic flows described in this document can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit) .
Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random-access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.
While this patent document contains many specifics, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this patent document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.
Only a few implementations and examples are described and other implementations, enhancements and variations can be made based on what is described and illustrated in this patent document.

Claims

A method of wireless communication, comprising:

receiving, at a user device, a configuration information associated with repeatedly performing transmissions on a channel;

determining, based on the configuration information, availability of one or more resources for performing transmissions on the channel to a network device;

upon detecting that the one or more resources is unavailable, scheduling transmissions performed on the channel in accordance with a next available resource;

upon detecting that the one or more resources are available, scheduling transmissions performed on the channel in accordance with the one or more resources; and

transmitting or receiving the repeatedly performing transmissions on the channel based on the configuration information.
The method of claim 1, wherein the one or more resources are in the time domain or frequency domain.
The method of claim 1, wherein the repeated performing transmissions is performed on a shared wireless channel associated with one transmission block.
The method of claim 1, wherein the configuration information includes a starting symbol number (S _i) of transmission number i in a time slot and a duration (L _i) of the transmission number i in the time slot.
The method of claim 1, wherein the configuration information includes a starting symbol number (S _j) of a first transmission in a time slot j and a total transmission duration (L _j) summed over transmissions on the channel in time slot j.
The method of claim 1, wherein the configuration information includes a starting symbol number (S _i) of transmission number i in a time slot and a total transmission duration (L) summed over transmissions on the channel.
The method of claim 1, wherein the configuration information includes a starting symbol number (S _j) of a first transmission in a time slot j and a total transmission duration (L) summed over transmissions on the channel.
The method of claim 1, wherein the configuration information includes a starting symbol number (S ₀) of a first transmission and a duration (L _i) of transmission number i in a time slot.
The method of claim 1, wherein the configuration information includes a starting symbol number (S ₀) of a first transmission and a total transmission duration (L) summed over transmissions on the channel in time slot j.
The method of claim 1, wherein the configuration information includes a starting symbol number (S ₀) of a first transmission and a total transmission duration (L) summed over transmissions on the channel.
The method of any of the aforementioned claims, wherein the channel corresponds to any of the PDCCH, PDSCH, PUCCH, PRACH channels of 4G mobile communication technology and 5G mobile communication technology.
The method of any of the aforementioned claims, wherein the configuration information associated with repeatedly transmitting a channel is included as part of uplink grant information from the network device and/or higher layer configuration information of the user device.
The method of any of the aforementioned claims, wherein the one or more resources that are not available includes a downlink symbol or a flexible symbol in a slot.
The method of claim 13, wherein slot format indicator (SFI) information provides indication of the downlink symbol or the flexible symbol, and wherein the SFI is included as part of the PDCCH channel.
The method of claim 14, wherein the SFI is dynamically indicated by the network device.
A method of wireless communication, comprising:

calculating, at a user device, a value of parameter wherein denotes a number of symbols allocated for a shared channel transmission across one or multiple slots;

determining, at the user device, a value of parameter N _RE based at least on wherein N _RE denotes a number of resource elements allocated for the shared channel transmission; and

computing a transport block size (TBS) based at least on the value of parameter N _RE.
The method of claim 16, wherein the value of parameter N _RE is based on N _RE=min (156, N' _RE) ·n _PRB, wherein N' _RE is based on wherein N _RE denotes a number of resource elements allocated for the shared channel transmission within a physical resource block (PRB) , RE denotes resource elements, DMRS denotes demodulation reference symbols, denotes a number of subcarriers in a frequency domain in the PRB, is a number of REs for DMRS per physical resource block (PRB) in a duration allocated for the shared channel transmission, and is an amount of overhead configured by one or more higher layer parameters, and n _PRB corresponds to a total number of allocated PRBs for the user device.
The method of claim 16, wherein the value of parameter is based on = min (P, L) , wherein L is a total number of symbols included across all shared channel transmissions or a total number of symbols for data transmission included across the all shared channel transmissions and P corresponds to a semi-statically configured value or a predetermined fixed value.
The method of claim 16, wherein the value of parameter is based on = a maximum number of available data symbols among all shared channel transmissions.
The method of claim 16, wherein the value of parameter is based on = a number of available data symbols of a predefined shared channel transmission, wherein the predefined shared channel transmission can be any one of the following: a first shared channel transmission, a shared channel transmission with a maximum number of data symbols, or a shared channel transmission with a maximum number of DMRS symbols.
The method of claim 16, wherein the value of parameter is based on or where L is a total number of symbols included in all the shared channel transmissions, N is a total number of the shared channel transmissions, and are floor and ceiling operations respectively.
The method of claim 16, wherein the value of parameter is based on = a maximum number of available data symbols in each shared channel transmission.
The method of claim 16, wherein the TBS is based at least in part on a modulation and coding scheme (MCS) further comprising:

upon determining that the MCS exceeds a threshold value, the value of parameter is based on = min (P, L) , wherein L is a total number of symbols for data transmission included across all the shared channel transmissions and P corresponds to a semi-statically configured value or a predetermined fixed value.
The method of claim 16, wherein the TBS is based at least in part on a modulation and coding scheme (MCS) further comprising:

upon determining that the MCS is equal to or less than a threshold value, the value of parameter is based on = a maximum number of available uplink data symbols among all the shared channel transmissions.
The method of claims 16 to 24, wherein the shared channel is a PUSCH or a PDSCH.
A method of wireless communication, comprising:

upon detection, at a user device, of a first uplink grant with a UL-SCH indicator field set to 0 and with a non-zero CSI request field, ignoring a Redundancy version bit field in the first uplink grant; and

upon detection of a second uplink grant with the UL-SCH indicator field set to 0, ignoring the Redundancy version bit field in the second uplink grant.
A method of wireless communication, comprising:

sending, to at least one user device, a configuration information associated with repeatedly performing transmissions on a channel, wherein the configuration information includes one or more of: (i) a starting symbol number (S _i) of transmission number i in a time slot, (ii) a duration (L _i) of the transmission number i in the time slot, (iii) a total transmission duration (L) summed over transmissions on the channel, and (iv) a starting symbol number (S ₀) of a first transmission.
A wireless communication apparatus comprising memory and at least one processor configured to implement the above-described methods.
A computer readable medium storing processor-executable code for implementing the above-described methods.