Patent Description:
The following abbreviations are herewith defined, some of which are referred to within the following description: Third Generation Partnership Project (3GPP), European Telecommunications Standards Institute (ETSI), Frequency Division Duplex (FDD), Frequency Division Multiple Access (FDMA), Long Term Evolution (LTE), New Radio (NR), Very Large Scale Integration (VLSI), Random Access Memory (RAM), Read-Only Memory (ROM), Erasable Programmable Read-Only Memory (EPROM or Flash Memory), Compact Disc Read-Only Memory (CD-ROM), Local Area Network (LAN), Wide Area Network (WAN), Personal Digital Assistant (PDA), User Equipment (UE), Uplink (UL), Evolved Node B (eNB), Next Generation Node B (gNB), Downlink (DL), Central Processing Unit (CPU), Graphics Processing Unit (GPU), Field Programmable Gate Array (FPGA), Dynamic RAM (DRAM), Synchronous Dynamic RAM (SDRAM), Static RAM (SRAM), Liquid Crystal Display (LCD), Light Emitting Diode (LED), Organic LED (OLED), Multiple-Input Multiple-Output (MIMO), Physical Uplink Shared Channel (PUSCH), Physical Downlink Shared Channel (PDSCH), Sounding Reference Signal (SRS), Time division multiplexing (TDM), Code division multiplexing (CDM), Orthogonal Cover Code (OCC), Cycling Shift (CS), Physical Resource Block (PRB), Hybrid Automatic Repeat Request-Acknowledge (HARQ-ACK), Media Access Control-Control Element (MAC-CE). Listen Before Talk (LBT), Maximum Channel Occupancy Time (MCOT), Radio Resource Control (RRC), cyclic prefix (CP), downlink control indicator (DCI), NR-access on unlicensed spectrum (NR-U).

For transmission on unlicensed spectrum, in order to achieve fair coexistence with other wireless systems, LBT (listen before talk) is required before the transmission on unlicensed spectrum. By means of performing energy detection on a certain channel, if the received power is below a predefined threshold, then the LBT is successful, which means the channel is deemed as empty and available for transmission. Only when the LBT is successful, an equipment can start the transmission on the channel and occupy the channel up to a maximum channel occupancy time (MCOT); otherwise, the equipment can't start the transmission and continue to performing LBT until a successful LBT.

3GPP <NUM> new radio (NR) can support both slot-based transmission and mini-slot based transmission. In the slot-based transmission, a starting position and an ending position for a transmission are bound to slot boundaries. In the mini-slot based transmission, multiple flexible starting symbols and ending symbols for PDSCH transmission and PUSCH transmission are defined in TS38. The corresponding starting symbol and duration for PUSCH type A and B are listed in below table <NUM>. In table <NUM>, "S" represents a starting symbol; "L" represents a duration of symbols in a transmission.

Based on the starting symbols and durations defined for normal CP (cyclic prefix), PUSCH type A has only one starting symbol and up to <NUM> ending symbols; PUSCH type B has up to <NUM> candidate starting symbols and <NUM> candidate ending symbols. The detailed values are listed in Table <NUM>. It is noted that the maximum ending symbols is symbol <NUM> so that one PUSCH transmission is guaranteed not across slot boundary.

NR-U (NR-access on unlicensed spectrum) supports scheduling multiple slots for PUSCH by a single UL grant, i.e. a single DCI format 0_1.

The DCI format 0_1 includes, among other fields, a field of time domain resource assignment. The field of time domain resource assignment may be set to "common" for all of the scheduled multiple slots. For example, as shown in <FIG>, assuming four slots are scheduled by a single UL grant, when the time domain resource assignment in the UL grant indicates the row index <NUM> of Table <NUM>, then the starting symbol and ending symbol are symbol <NUM> and symbol <NUM> (calculated by <NUM>+<NUM>-<NUM>). If the field of time domain resource assignment is set to common for the four scheduled slots, then the starting symbol and ending symbol for all of the first to fourth slots are <NUM> and <NUM>, respectively. Thus, transmission gaps are formed between the first slot and the second slot, between the second slot and the third slot, and between the third slot and the fourth slot. Therefore, non-contiguous time domain resource allocation is caused. This non-contiguous time domain resource allocation is not suitable for burst based transmission on unlicensed spectrum because LBT is needed for each of the multiple scheduled slots. That means that any transmission gap bears the risk of 'losing' the channel to another node that sensed the channel to be idle in such a gap and henceforth starts its own transmission.

In order to form time-contiguous domain resource allocation without transmission gaps, a multiple full slot scheduling may be used as shown in <FIG>. However, the scheduling flexibility is restricted since the multiple scheduled slots have to start from the symbol <NUM>.

In the above tables <NUM> and <NUM>, S represents the starting position, L represents the duration, K2 represents slot level offset between the slot where UL grant is received and the slot where associated PUSCH is scheduled. µPUSCH is the subcarrier spacing. Different subcarrier spacing values correspond to different values of K2. So, j is used to indicate such difference.

<NPL>) discloses views on possible HARQ related issues to be addressed when designing HARQ enhancements for NR-U operation and multi-TTI scheduling.

<NPL>) discusses frame structure issues and views thereon. Another example of multi-slot scheduling in NR-U can be found in the later published document <CIT>.

Methods and apparatuses for multi-slot scheduling on unlicensed spectrum are disclosed. Several solutions are proposed to support time-contiguous domain resource allocation for multiple slots scheduled by a single UL grant for uplink transmission on unlicensed spectrum. The same principle may apply to downlink transmission. Any embodiment, aspect, example or implementation not claimed, is only presented as information.

Understanding that these drawings depict only some embodiments, and are not therefore to be considered as limiting of scope, the embodiments will be described and explained with additional specificity and detail using accompanying drawings, in which:.

Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may generally all be referred to herein as a "circuit", "module" or "system". Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine-readable code, computer readable code, and/or program code, referred to hereafter as "code".

Certain functional units described in this specification may be labeled as "modules", in order to more particularly emphasize their independent implementation. For example, a module may be implemented as a hardware circuit comprising custom very-large-scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components.

Nevertheless, the executables of an identified module need not be physically located together, but, may include disparate instructions stored in different locations which, when joined logically together, include the module and achieve the stated purpose for the module.

Similarly, operational data may be identified and illustrated herein within modules and may be embodied in any suitable form and organized within any suitable type of data structure. This operational data may be collected as a single data set, or may be distributed over different locations including over different computer readable storage devices.

The computer readable storage medium may be a storage device storing code. The storage device may be, for example, but need not necessarily be, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

A non-exhaustive list of more specific examples of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or Flash Memory), portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

Code for carrying out operations for embodiments may be any number of lines and may be written in any combination of one or more programming languages including an object-oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the "C" programming language, or the like, and/or machine languages such as assembly languages. The code may be executed entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the very last scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid any obscuring of aspects of an embodiment.

This code may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which are executed via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the schematic flowchart diagrams and/or schematic block diagrams for the block or blocks.

The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices, to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks.

The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices, to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code executed on the computer or other programmable apparatus provides processes for implementing the functions specified in the flowchart and/or block diagram block or blocks.

<FIG> depicts an embodiment of a wireless communication system <NUM> for multi-slot scheduling on unlicensed spectrum. In one embodiment, the wireless communication system <NUM> includes remote units <NUM> and base units <NUM>. Even though a specific number of remote units <NUM> and base units <NUM> are depicted in <FIG>, one skilled in the art will recognize that any number of remote units <NUM> and base units <NUM> may be included in the wireless communication system <NUM>.

In one embodiment, the remote units <NUM> may include computing devices, such as desktop computers, laptop computers, personal digital assistants (PDAs), tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle on-board computers, network devices (e.g., routers, switches, modems), or the like. The remote units <NUM> may be referred to as subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, user equipment (UE), user terminals, a device, or by other terminology used in the art.

The base units <NUM> may be distributed over a geographic region. In certain embodiments, a base unit <NUM> may also be referred to as an access point, an access terminal, a base, a base station, a Node-B, an eNB, a gNB, a Home Node-B, a relay node, a device, or by any other terminology used in the art. The base units <NUM> are generally part of a radio access network that includes one or more controllers communicably coupled to one or more corresponding base units <NUM>. These and other elements of radio access and core networks are not illustrated, but are well known generally by those having ordinary skill in the art.

In one implementation, the wireless communication system <NUM> is compliant with 3GPP <NUM> new radio (NR). More generally, however, the wireless communication system <NUM> may implement some other open or proprietary communication protocol.

The base units <NUM> may serve a number of remote units <NUM> within a serving area, for example, a cell (or a cell sector) or more cells via a wireless communication link.

<FIG> depicts one embodiment of an apparatus <NUM> that may be used for multi-slot scheduling on unlicensed spectrum. The apparatus <NUM> includes one embodiment of the remote unit <NUM>. Furthermore, the remote unit <NUM> may include a processor <NUM>, a memory <NUM>, an input device <NUM>, a display <NUM>, a transmitter <NUM>, and a receiver <NUM>. In some embodiments, the input device <NUM> and the display <NUM> are combined into a single device, such as a touch screen. In certain embodiments, the remote unit <NUM> may not include any input device <NUM> and/or display <NUM>. In various embodiments, the remote unit <NUM> may include at least one of the processor <NUM>, the memory <NUM>, the transmitter <NUM> and the receiver <NUM>, and may not include the input device <NUM> and/or the display <NUM>.

For example, the processor <NUM> may be a microcontroller, a microprocessor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processing unit, a field programmable gate array (FPGA), or similar programmable controller.

For example, the memory <NUM> may include a RAM, including dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), and/or static RAM (SRAM). In some embodiments, the memory <NUM> stores data relating to system parameters.

In some embodiments, the input device <NUM> may be integrated with the display <NUM>, for example, as a touch screen or similar touch-sensitive display. In some embodiments, the input device <NUM> includes a touch screen such that text may be input using a virtual keyboard displayed on the touch screen and/or by handwriting on the touch screen.

As another, non-limiting example, the display <NUM> may include a wearable display such as a smart watch, smart glasses, a heads-up display, or the like.

For example, the input device <NUM> and display <NUM> may form a touch screen or similar touch-sensitive display.

The transmitter <NUM> is used to provide UL communication signals to the base unit <NUM> and the receiver <NUM> is used to receive DL communication signals from the base unit <NUM>. In various embodiments, the transmitter <NUM> and the receiver <NUM> may transmit and receive resources via different cells.

<FIG> depicts one embodiment of another apparatus <NUM> that may be used for multi-slot scheduling on unlicensed spectrum. The apparatus <NUM> includes one embodiment of the base unit <NUM>. Furthermore, the base unit <NUM> may include at least one of a processor <NUM>, a memory <NUM>, an input device <NUM>, a display <NUM>, a transmitter <NUM> and a receiver <NUM>. As may be appreciated, the processor <NUM>, the memory <NUM>, the input device <NUM>, the display <NUM>, the transmitter <NUM>, and the receiver <NUM> may be substantially similar to the processor <NUM>, the memory <NUM>, the input device <NUM>, the display <NUM>, the transmitter <NUM>, and the receiver <NUM> of the remote unit <NUM>, respectively.

Although only one transmitter <NUM> and one receiver <NUM> are illustrated, the base unit <NUM> may have any suitable number of transmitters <NUM> and receivers <NUM>.

<FIG> illustrate a schematic view of a time-contiguous domain resource allocation for multiple slots scheduled by a single UL grant. As shown in <FIG>, the time-contiguous domain resource allocation for multiple UL slots is labeled as one UL burst. The time-contiguous domain resource may start from any symbol in the first slot, and end at any symbol in the last slot. The multiple slots scheduled by a single UL grant may be any integer, and preferably be <NUM> or more. <FIG> shows that the total scheduled slots are four. The slots between the first slot and the last slot are referred to as the middle slots. In <FIG>, the second slot and the third slot are middle slots. The number of middle slots equals the total scheduled slots minus <NUM>. Therefore, in the situation that the total scheduled slots are <NUM> slots, the number of middle slots is zero. To satisfy the time-contiguous domain resource allocation, all of the symbols (Symbol <NUM> to Symbol <NUM>) in each of the middle slots have to be fully scheduled.

Both the existing PUSCH mapping type A and type B may be used to indicate time domain resource allocation for a single slot. According to a first embodiment, described below in connection with <FIG>, a new PUSCH mapping type C is introduced to indicate time domain resource allocation for multiple slots.

As the time domain resource is contiguous across the multiple slots, it is only necessary to indicate a starting position and an ending position of the allocated resource. The starting position refers to a starting symbol in the first slot. Since the starting position is always in the first slot (in other words, the index of the first slot is always <NUM>), it is enough to determine the starting position according to the starting symbol. The ending position refers to an ending symbol in the last slot. The ending position is determined according to an index of the last slot and the ending symbol in the last slot. The index of the last slot may be calculated based on the number of scheduled slots. In particular, the index of the last slot equals the number of scheduled slots. In the example of <FIG>, the index of the last slot is <NUM>.

In the first embodiment, there is a number of alternative implementation to determine the starting position and the ending position of the allocated resource.

In a first alternative implementation of the first embodiment, a starting symbol in the first slot, an ending symbol in the last slot and the number of total scheduled slots are used for indicating the starting position and the ending position of the allocated resource.

The starting symbol in the first slot is selected from a set of starting symbols. The ending symbol in the last slot is selected from a set of ending symbols. In the first alternative implementation of the first embodiment, the set of starting symbols and the set of ending symbols are configured by RRC signaling. The number of total scheduled slots is a number that is no more than the maximum number of slots scheduled by a single UL grant. The maximum number of slots scheduled by a single UL grant may be configured by RRC signaling.

Upon receiving an indication of a starting symbol in the first slot, the indication of the ending symbol in the last slot, as well as the total number of scheduled slots as part of the received UL grant, UE knows the time domain resource allocation for the multiple slots, i.e. the starting position and the ending position of the allocated resource.

In a second alternative implementation of the first embodiment, similar to the first alternative implementation, a starting symbol in the first slot, an ending symbol in the last slot and the total number of scheduled slots are used for indicating the starting position and the ending position of the allocated resource; and the starting symbol in the first slot and the ending symbol in the last slot are selected, respectively from a set of starting symbols and a set of ending symbols.

The second alternative implementation differs from the first alternative implementation in that the starting symbols and ending symbols for PUSCH mapping type B shown in Table <NUM> are chosen as a set of starting symbols and a set of ending symbols. In this way, the RRC signaling for configuring the set of starting symbols and the set of ending symbols is not needed.

For the first and second alternative implementations of the first embodiment, the field size of time domain resource allocation in the single UL grant depends on the following three factors: (<NUM>) the number of possible starting symbols; (<NUM>) the number of possible ending symbols; and (<NUM>) the maximum number of slots scheduled by a single UL grant. The three factors may be separately indicated in the UL grant and each factor needs ceil(log<NUM>(the number of possible values)) bits. Alternatively, the three factors may be jointly coded in the UL grant, so that the field size is dependent on the number of possible combinations.

In a third alternative implementation of the first embodiment, a starting symbol in a first slot and a duration of the total number of scheduled symbols (i.e. the number of total scheduled symbols) are used for indicating a starting position and an ending position of the allocated resource.

The starting symbol in the first slot is selected from a set of starting symbols. In the third alternative implementation of the first embodiment, a set of starting symbols is configured by RRC signaling. The duration of the total number of scheduled symbols is dependent on the maximum number of slots scheduled by the single UL grant, which may be configured by RRC signaling.

Upon receiving an identification of the starting symbol in the first slot and the duration of the total scheduled symbols contained in the UL grant, the UE knows the time domain resource allocation for the multiple slots, i.e. the starting position and the ending position of the allocated resource. In particular, the starting position is the starting symbol in the first slot. The ending position can be calculated from the starting symbol in the first slot and the duration of the total scheduled symbols contained in the UL grant. For example, suppose the starting symbol is x and the duration of the total scheduled symbols is z, the index of the last scheduled slot (which equals the number of total scheduled slots) is N = ceil ((x+z)/<NUM>) and the ending symbol in the last slot is y = x+z-(N-<NUM>)*<NUM>-<NUM>. As an example, if the starting symbol is <NUM> and the duration of the total scheduled symbols is <NUM>, then the number of the last scheduled slot is N = ceil ((<NUM>+<NUM>)/<NUM>) =<NUM>, and the last symbol in the last slot is y = <NUM> + <NUM> - (<NUM>-<NUM>)*<NUM> -<NUM> = <NUM>.

In the third alternative implementation of the first embodiment, the field size of time domain resource assignment in the single UL grant depends on the following two factors: (<NUM>) the number of possible starting symbols; and (<NUM>) the number of bits for indicating a possible duration of symbols. The number of bits for indicating the number of possible starting symbols equals to ceil(log<NUM>(the number of possible starting symbols)). The number of bits for indicating the duration of symbols equals ceil(log<NUM>(the maximum number of symbols)). For example, assuming maximum <NUM> slots can be scheduled by single UL grant, then the maximum number of symbols is <NUM> so that <NUM> bits in the UL grant are required to indicate the duration.

A fourth alternative implementation of the first embodiment is similar to the third alternative implementation of the first embodiment. The only difference of the fourth alternative implementation from the third alternative implementation lies in that the starting symbols for PUSCH mapping type B shown in Table <NUM> are chosen as the set of starting symbols. In this way, the RRC signaling for configuring the set of starting positions is not needed.

In a fifth alternative implementation of the first embodiment, symbol <NUM> is always used as the starting symbol in the first slot. The ending symbol in the last slot is selected from a set of ending symbols. In the fifth alternative implementation of the first embodiment, the set of ending symbols is configured by RRC signaling. The number of total scheduled slots, that is no more than the maximum number of slots scheduled by a single UL grant, is also indicated in the fifth alternative implementation. The maximum number of slots scheduled by a single UL grant may be configured by RRC signaling.

Upon receiving the starting symbol in the first slot which is always symbol <NUM>, the ending symbol in the last slot and the number of total scheduled slots contained in the UL grant, the UE knows the time domain resource allocation for the multiple slots.

The field size representing the number of total scheduled slots equals to ceil(log<NUM>(the maximum number of slots)). For example, assuming a maximum of <NUM> slots can be scheduled by a single UL grant, then <NUM> bits in the UL grant are required to indicate the duration.

A sixth alternative implementation of the first embodiment is similar to the fifth alternative implementation of the first embodiment. The only difference of the sixth alternative implementation from the fifth alternative implementation lies in that the ending symbols for PUSCH mapping type B show in Table <NUM> are chosen as the set of ending symbols. In this way, the RRC signaling for configuring the set of symbols is not needed.

A seventh alternative implementation of the first embodiment is similar to the third alternative implementation of the first embodiment. The only difference of the seventh alternative implementation from the third alternative implementation lies in that, instead of choosing a starting symbol from a set of possible starting symbols, symbol <NUM> is always used as the starting symbol in the first slot.

Upon receiving the time domain resource allocation contained in the UL grant, UE knows the number of total scheduled symbols for the multiple slots. For example, suppose the duration of the total scheduled symbols is z, the index of the last scheduled slot (which equals the number of total scheduled slots) is N = ceil (z/<NUM>) and the ending symbol in the last slot is y = z-(N-<NUM>)*<NUM>-<NUM>.

The number of bits required for indicating the number of total scheduled symbols equals ceil(log<NUM>(the maximum number of symbols)). For example, assuming a maximum of <NUM> slots (e.g. <NUM> symbols) can be scheduled by a single UL grant ceil(log<NUM>(the maximum number of symbols)) = <NUM> bits in the UL grant are required to indicate the duration of scheduled symbols.

In an eight alternative implementation of the first embodiment, symbol <NUM> is always used as the starting symbol in the first slot. The ending symbol index in the last slot is directly indicated in the UL grant. The possible ending symbol may be any of <NUM> to <NUM>.

In the above first to sixth alternative implementations, the starting symbol and the ending symbol are selected from a set configured by RRC signaling or a set predetermined for PUSCH mapping type B. The ending symbol indication contained in the UL grant may be an index to the set. For example, an ending symbol indication of "<NUM>" means that the first value contained in the set is indicated. For example, if the set of the ending symbols are { <NUM>, <NUM>, <NUM>, <NUM>,. }, the ending symbol indication of "<NUM>" means that ending symbol is <NUM> (the first value contained in the set). On the other hand, in the eighth alternative implementation, the ending symbol indication is the ending symbol value itself. For example, if the ending symbol indication is "<NUM>", the ending symbol is <NUM>.

In the eighth alternative implementation, the number of total scheduled slots is also indicated.

In a ninth alternative implementation of the first embodiment, time domain resource assignment in UL grant is used to determine the starting symbol of the first slot and the ending symbol of the last slot. In time domain resource assignment field a starting symbol index (denoted as x) and a duration (denoted as L) are indicated. For multi-slot scheduling, in one variable implementation, the indicated starting symbol index is the starting symbol index in the first scheduled slot and the indicated duration is the duration in the last scheduled slot. Since the last scheduled slot starts from Symbol <NUM>, the ending symbol index in the last scheduled slot is equal to (L - <NUM>). For multi-slot scheduling, in another variable implementation, the indicated starting symbol index is the starting symbol index in the first scheduled slot and the indicated duration is used to derive the ending symbol index in the last scheduled slot. In detail, the ending symbol (denoted as y) in the last scheduled slot is calculated by an equation y = x + L -<NUM>. <FIG> shows a PUSCH mapping type B indication and a PUSCH mapping type C indication. The type B indicates one slot, in which x is the starting symbol and y is the ending symbol. In the type C, the starting symbol (x) may be interpreted as the starting symbol in the first slot. In addition, the ending symbol (y) may be interpreted as the ending symbol in the last slot. Here, full slot assignment is assumed for the middle slots (the second and third slots in <FIG>).

In the ninth alternative implementation of the first embodiment, the number of scheduled slots or the number of full slots in the middle (referred to as the middle slots) is indicated in the UL grant. It is obvious that the number of middle slots equals the number of scheduled slots minus <NUM>. In consideration that the minimum number of the scheduled slots is <NUM>, the minimum number of middle slots is zero.

In a tenth alternative implementation of the first embodiment, current time domain resource allocation in UL grant is applied for the first slot and the full slot assignment is assumed for the second to last slots of the multiple slots. In the tenth alternative implementation, to satisfy the time-contiguous domain resource allocation, the ending symbol of the first slot has to be set to the ending symbol of the first slot, i.e., symbol <NUM>. The number of scheduled slots needs to be indicated in the UL grant.

In an eleventh alternative implementation of the first embodiment, a series of time domain resource allocation patterns are predefined by RRC signaling. The field of time domain resource assignment in UL grant is used to indicate a certain time domain resource allocation pattern to UE.

For example, the PUSCH time domain resource allocation in RRC configuration for PUSCH mapping type C may be defined as below:
<IMG>.

In the above definition, X equals <NUM> for type A or type B. For type C, X equals <MAT> so as to support up to N full slots or <NUM>*N contiguous symbols. For example, if N=<NUM>, then <NUM> bits are needed to indicate the time domain resource allocation from <NUM> symbol to <NUM> contiguous symbols. Alternatively, to reduce the signaling overhead and exclude the potential resource allocation with smaller than <NUM> symbols, X equals <MAT> for type C so as to support up to N full slots or <NUM>*N contiguous symbols. For example, if N=<NUM>, then <NUM> bits are needed to indicate the time domain resource allocation from <NUM> symbol to <NUM> contiguous symbols plus <NUM> symbols (i.e. from <NUM> contiguous symbols to <NUM> contiguous symbols).

In all of the varieties of the first embodiment, the number of the maximum slots that can be scheduled by a single UL grant is set to N, e.g. <NUM>, in <FIG>. In this sense, we assume that the number of the minimum slots that can be scheduled by a single UL grant is <NUM>. Therefore, in the condition that <NUM> is the maximum number, the field size of the number of total scheduled slots equals ceil(log<NUM>(the maximum number of slots)) = ceil(log<NUM><NUM>) = <NUM>.

However, if the number of the total scheduled slots equals <NUM>, the time domain resource allocated in <NUM> slot is definitely contiguous. Therefore, it is preferable to distinguish, by different UL grants, a multi-slot scheduling in which the number of the scheduled slots is larger than <NUM> and a single slot scheduling in which the number of the scheduled slots is set to <NUM>. The multi-slot scheduling covers <NUM> to N slots, where N is RRC configured maximum number of slots scheduled by a single UL grant. In this condition, the number of required bits for indicating the number of scheduled slots is equal to ceil(log<NUM>(N-<NUM>+<NUM>))=ceil(log<NUM>(N-<NUM>)). For example, when N is set to <NUM>, <NUM> bits can be used to indicate <NUM>, <NUM>, <NUM> or <NUM> scheduled slots.

On the other hand, if one UL grant has to be used for scheduling <NUM> to N slots, the minimum number of scheduled slots would be <NUM>. In this condition, the number of required bits for indicating the number of scheduled slots is equal to ceil(log<NUM>(N-<NUM>+<NUM>))=ceil(log<NUM>N). For example, when N is set to <NUM>, <NUM> bits can be used to indicate <NUM>, <NUM>, <NUM> or <NUM> scheduled slots. For another example, when N is set <NUM>, <NUM> bits are needed to indicate <NUM>, <NUM>, <NUM>, <NUM> or <NUM> scheduled slots.

In the first embodiment, the number of scheduled slots is indicated in the UL grant. As an alternative, the number of scheduled middle slots may be indicated in the UL grant. Due to the requirement of time-contiguous domain allocation, only the first slot and the final slot may be a partial slot, which means the starting symbol in the first slot is after symbol <NUM> or the ending symbol in the final slot is before symbol <NUM>. On the other hand, all of the middle slots that are between the first slot and the final slot have to be full, which means that the starting symbol in each middle slot is always symbol <NUM> and the ending symbol of each middle slot is always symbol <NUM>. So, if the UL grant is used for scheduling minimum <NUM> slots, then there is no ambiguity for UE to determine the time domain resource allocation when the number of scheduled middle slots is indicated. In this way, the total number of actually scheduled slots can be minimum <NUM> slots and maximum N slots. The number of required bits for indicating the number of scheduled middle slots is equal to ceil(log<NUM>(N-<NUM>+<NUM>))=ceil(log<NUM>(N-<NUM>)). For example, when N is configured to <NUM>, <NUM> bits can be used to indicate <NUM>, <NUM>, <NUM> or <NUM> scheduled middle slots. Correspondingly, the total number of scheduled slots can be <NUM>, <NUM>, <NUM> or <NUM>.

In the first embodiment, a new PUSCH mapping type C is introduced to indicate time-contiguous resource allocation for multiple slots. According to a second embodiment, the existing PUSCH mapping type A and type B are used in combination to indicate time-contiguous domain resource allocation for multiple slots.

The time-contiguous resource allocation for multi-slot transmission includes four cases: (<NUM>) all the slots are full slots; (<NUM>) the first slot is a partial slot and all the remaining slots are full slots; (<NUM>) the first to the last second slots are full slots and the last slot is a partial slot; (<NUM>) the first slot and the last slot are partial slots and all the middle slots are full slots. A full slot means that the starting symbol is symbol <NUM> and the ending symbol is symbol <NUM>. A partial slot includes three cases: in a first case, the starting symbol is after symbol <NUM> and the ending symbol is Symbol <NUM>; in a second case, the starting symbol is Symbol <NUM> and the ending symbol is before Symbol <NUM>; in a third case, the starting symbol is after Symbol <NUM> and the ending symbol is before symbol <NUM>.

In the first case, all the slots can be scheduled as PUSCH mapping type A since all the slots start from symbol <NUM> and occupy <NUM> symbols. Alternatively, all the slots may be scheduled as PUSCH mapping type B since PUSCH mapping type B may start from Symbol <NUM> and end at any symbol (including Symbol <NUM>) within one slot.

In the second case, the first slot should be scheduled as PUSCH mapping type B since it doesn't start from symbol <NUM> and all the other slots are full slots and can be scheduled as PUSCH mapping type A since all the other slots start from symbol <NUM> and occupy <NUM> symbols. Alternatively, all the other slots may be scheduled as PUSCH mapping type B since PUSCH mapping type B may start from Symbol <NUM> and end at any symbol (including Symbol <NUM>) within one slot.

In the third case, the last slot may be scheduled as PUSCH mapping type A if the last slot occupies at least <NUM> symbols or scheduled as PUSCH mapping type B. All the other slots are full slots and may be scheduled as PUSCH mapping type A or PUSCH mapping type B.

In the fourth case, the last slot may be scheduled as PUSCH mapping type A if the last slot occupies at least <NUM> symbols or scheduled as PUSCH mapping type B. The first slot should be scheduled as PUSCH mapping type B since it doesn't start from symbol <NUM>. All the middle slots are full slots and may be scheduled as PUSCH mapping type A or PUSCH mapping type B.

As can be seen from the analysis of the four cases, PUSCH mapping type A and/or PUSCH mapping type B may be used individually or in combination to schedule a time-contiguous resource allocation for multi-slot transmission. There are various varieties in the second embodiment.

According to the claimed implementation, separate mapping type may be specified for the first slot, all the middle slots, and the last slot.

In a second alternative implementation, separate mapping type may be specified for the first slot and the last slot. All the middle slots may be fixed to mapping type A or type B.

In a third alternative implementation, separate mapping type may be specified for the middle slots and the last slot. The first slot may use mapping type A if it starts from symbol <NUM> and use mapping type B if it starts from other symbols than symbol <NUM>.

In a fourth alternative implementation, separate mapping type may be specified for the first slot and the middle slots. The last slot may use mapping type A if the last slot occupies at least <NUM> symbols and use mapping type B if the last slot occupies <NUM>, <NUM> or <NUM> symbols.

In a fifth alternative implementation, mapping type may be specified only for the last slot. The first slot uses mapping type A if it starts from symbol <NUM> and use mapping type B if it starts from any of symbols <NUM> to <NUM>. All the middle slots may be fixed to mapping type A or type B.

In a sixth alternative implementation, the first slot may use mapping type A if it starts from symbol <NUM> and use mapping type B if it starts from any of symbols <NUM> to <NUM>. All the middle slots may be fixed to mapping type A or type B. The last slot may use mapping type A if the last slot occupies at least <NUM> symbols and use mapping type B if the last slot occupies <NUM>, <NUM> or <NUM> symbols.

<FIG> is a flow chart diagram illustrating a method for multi-slot scheduling on unlicensed spectrum.

In step <NUM>, the base unit transmits a downlink control information (DCI) for scheduling time-contiguous data transmission in multiple slots to a remote unit, wherein the DCI includes an indicator indicating time domain resource allocation in the multiple slots.

In step <NUM>, the remote unit receives the DCI for scheduling time-contiguous data transmission in multiple slots.

In step <NUM>, the remote unit determines a starting position and an ending position of the scheduled time-contiguous data transmission, based on the indicator included in the DCI.

In step <NUM>, the remote unit, in response to a successful listen before talk (LBT), transmits data from the determined starting position to the determined ending position.

Claim 1:
A method performed by a remote unit, comprising:
receiving (<NUM>) a downlink control information, DCI, for scheduling time-contiguous data transmission in multiple slots, wherein the DCI includes an indicator indicating the time domain resource allocation in the multiple slots;
determining (<NUM>), based on the indicator, a starting position and an ending position of the scheduled time-contiguous data transmission; and
transmitting (<NUM>) data from the determined starting position to the determined ending position; wherein the data are transmitted in response to a successful listen-before-talk, LBT, and characterized in that the indicator includes separate indications of PUSCH mapping types for a first slot, a last slot and middle slot(s) of the multiple slots.