Patent Description:
The following abbreviations and acronyms are herewith defined, at least some of which are referred to within the following description.

Third Generation Partnership Project ("3GPP"), Positive-Acknowledgment ("ACK"), Channel State Information ("CSI"), Control Channel ("CCH"), Device-to-Device ("D2D"), Downlink Control Information ("DCI"), Downlink ("DL"), Downlink Pilot Time Slot ("DwPTS"), Evolved Node B ("eNB"), European Telecommunications Standards Institute ("ETSI"), Frequency-Division Multiplexing ("FDM"), Frequency Division Multiple Access ("FDMA"), Guard Period ("GP"), Hybrid Automatic Repeat Request ("HARQ"), Long Term Evolution ("LTE"), LTA Advanced ("LTE-A"), Medium Access Control ("MAC"), Multiple Access ("MA"), Modulation Coding Scheme ("MCS"), Mobility Management Entity ("MME"), Machine Type Communication ("MTC"), Narrowband ("NB"), Negative-Acknowledgment ("NACK") or ("NAK"), Next Generation Node B ("gNB"), Orthogonal Frequency Division Multiplexing ("OFDM"), Packet Data Convergence Protocol ("PDCP"), Packet Data Network ("PDN"), PDN Gateway ("P-GW"), Physical Broadcast Channel ("PBCH"), Physical Downlink Control Channel ("PDCCH"), Physical Downlink Shared Channel ("PDSCH"), Physical Sidelink Control Channel ("PSCCH"), Physical Sidelink Shared Channel ("PSSCH"), Physical Hybrid ARQ Indicator Channel ("PHICH"), Physical Random Access Channel ("PRACH"), Physical Resource Block ("PRB"), Physical Uplink Control Channel ("PUCCH"), Physical Uplink Shared Channel ("PUSCH"), Quality of Service ("QoS"), Radio Resource Control ("RRC"), Receive ("RX"), Serving Gateway ("S-GW"), Scheduling Assignment ("SA"), Scheduling Request ("SR"), Shared Channel ("SCH"), Sidelink Control Information ("SCI"), System Information Block ("SIB"), Transport Block ("TB"), Transport Block Size ("TBS"), Transmission Control Protocol ("TCP"), Time-Division Multiplexing ("TDM"), Transmission and Reception Point ("TRP"), Transmission Time Interval ("TTI"), Transmit ("TX"), Uplink Control Information ("UCI"), User Datagram Protocol ("UDP"), User Entity/Equipment (Mobile Terminal) ("UE"), Uplink ("UL"), Universal Mobile Telecommunications System ("UMTS"), Uplink Pilot Time Slot ("UpPTS"), Vehicle-to-Vehicle ("V2V"), and Worldwide Interoperability for Microwave Access ("WiMAX"). As used herein, "HARQ-ACK" may represent collectively the Positive Acknowledge ("ACK") and the Negative Acknowledge ("NAK"). ACK means that a TB is correctly received while NAK means a TB is erroneously received.

In mobile communication networks, a remote UE may operate in an indirect communication mode where the remote UE accesses mobile network communication services via a relay UE. Both D2D and V2V communications are broadcast-based communications. However, broadcast-based communications do not meet requirements on QoS, reliability, complexity and power consumption.

In the prior art, 3GPP DRAFT; R1-<NUM>, considered the closest prior art, discloses scheduling assignment procedures for Mode <NUM> User Equipments, while <CIT> discloses a wireless device comprising a ProSe UE-to-network relay; the wireless device may request transmission resources from network node according to the data transmission pattern information.

The invention is defined with reference to the appended claims. According to the invention, a method according to claim <NUM> and a device according to claim <NUM> are provided.

The embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:.

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 execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the schematic flowchart diagrams and/or schematic block diagrams.

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 which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the schematic flowchart diagrams and/or schematic block diagram.

In order to meet requirements on QoS, reliability, complexity and power consumption, unicast-based sidelink communications are provided. Disclosed herein are methods, apparatus, and systems that support a relay UE to perform the resource allocation for sidelink communication, indicate the data transmission and/or feedback information transmission from the remote UE. As described herein, the relay UE determines a transmission-reception pattern and generates an indicator of the same. The transmission-reception pattern indicator allows a remote UE to identify a relay UE reception frame, where the remote UE is permitted to transmit data and/or HARQ feedback information. Additionally, the relay UE and/or remote UE may send SCI that contains a scheduling assignment function differentiation flag that to differentiate an associated data transmission from a feedback ACK/NACK information transmission.

<FIG> depicts a wireless communication system <NUM> for sidelink control information indication, according to embodiments of the disclosure. In one embodiment, the wireless communication system <NUM> includes remote units <NUM>, base units <NUM>, and communication links <NUM>. Even though a specific number of remote units <NUM>, base units <NUM>, and communication links <NUM> are depicted in <FIG>, one of skill in the art will recognize that any number of remote units <NUM>, base units <NUM>, and communication links <NUM> may be included in the wireless communication system <NUM>.

In one implementation, the wireless communication system <NUM> is compliant with the LTE, LTE advanced and subsequent cellular network system specified in the 3GPP specifications. More generally, however, the wireless communication system <NUM> may implement some other open or proprietary communication network, for example, WiMAX, among other networks.

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), smart appliances (e.g., appliances 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 communicate directly with one or more of the base units <NUM> via uplink ("UL") and downlink ("DL") communication signals. Furthermore, the UL and DL communication signals may be carried over the communication links <NUM>. In addition, the remote units <NUM> may communicate indirectly with a base unit <NUM> via a relay unit <NUM>. Here, a relay unit <NUM> communicates with one or more remote units <NUM> using sidelink communication signals carried over one or more relay links <NUM>. A relay unit <NUM> is a remote unit <NUM> that also serves as a relay for one or more additional remote units <NUM>.

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 terminal, a base, a base station, a Node-B, an eNB, a gNB, a Home Node-B, a relay node, a femtocell, an access point, a device, or by any other terminology used in the art. The base units <NUM> are generally part of a radio access network ("RAN") that may include one or more controllers communicably coupled to one or more corresponding base units <NUM>. These and other elements of radio access network are not illustrated but are well known generally by those having ordinary skill in the art. The base units <NUM> connect to the mobile core network <NUM> via the RAN.

The base units <NUM> may communicate directly with one or more of the remote units <NUM> via communication signals. The base units <NUM> communicate directly with the one or more relay units <NUM> via the communication signals. Generally, the base units <NUM> transmit downlink ("DL") communication signals to serve the remote units <NUM> and/or relay units <NUM> in the time, frequency, and/or spatial domain. Furthermore, the DL communication signals may be carried over the communication links <NUM>. The communication links <NUM> may be any suitable carrier in licensed or unlicensed radio spectrum. The communication links <NUM> facilitate communication between one or more of the remote units <NUM> (and/or relay units <NUM>) and one or more of the base units <NUM>.

The wireless communication system <NUM> includes one or more relay units <NUM> capable of relaying traffic of the remote units <NUM> to the base units <NUM>. As noted above, the relay units <NUM> are remote units <NUM> capable of relaying the traffic between a base unit <NUM> and another remote unit <NUM>. As such, a relay unit maintains its own network connections. In one embodiment, a relay unit <NUM> may communicate with a remote host <NUM> via a network connection with a base unit <NUM> and the mobile core network <NUM>. The remote units <NUM> and relay units <NUM> communicate using relay links <NUM>. In one embodiment, the relay links <NUM> may be any suitable carrier in licensed or unlicensed radio spectrum. Examples of relay links <NUM> include, but are not limited to LTE-direct links, WiFi-direct links, and the like.

In one embodiment, the mobile core network <NUM> is an evolved packet core ("EPC"). In another embodiment, the mobile core network <NUM> may be a <NUM> core network. The mobile may be coupled to a data network <NUM>, like the Internet and private data networks, among other data networks. In some embodiments, the remote units <NUM> and/or relay units <NUM> communicate with a remote host <NUM> via a network connection with the mobile core network <NUM>. Each mobile core network <NUM> belongs to a single public land mobile network ("PLMN").

The mobile core network <NUM> includes several network elements. As depicted, the mobile core network <NUM> includes at least one MME <NUM>, at least one S-GW <NUM>, and at least one P-GW <NUM>. Although a specific number of MMEs <NUM>, S-GWs <NUM>, and P-GWs <NUM> are depicted in <FIG>, one of skill in the art will recognize that any number of MMEs <NUM>, S-GWs <NUM>, and P-GWs <NUM> may be included in the mobile core network <NUM>.

The MME <NUM> is a control plane network element that handles signaling related to mobility and security for the remote unit <NUM>. The MME <NUM> is a termination point for a NAS connection of the remote unit <NUM> to the mobile core network <NUM>. The S-GW <NUM> is a user plane element that connects the RAN to the mobile core network <NUM>. The S-GW <NUM> serves the remote unit <NUM> by routing incoming/outgoing IP packets. The P-GW <NUM> is a user plane element that connects the mobile core network <NUM> to an external (IP) network, such as the data network <NUM>.

As depicted, a relay unit <NUM> may provide a remote unit <NUM> with access to a base unit <NUM>. A relay unit <NUM> used sidelink communications to communicate with one or more remote units <NUM>. To facilitate the sidelink communication, the relay unit <NUM> may indicate a transmission-reception pattern to the remote unit <NUM>, e.g., using sidelink control information ("SCI") sent on a PSCCH, as discussed in greater detail below. Additionally, the remote unit <NUM> and/or relay unit <NUM> may indicate whether a SCI message includes feedback information and/or is associated with a data transmission on the sidelink data channel, as discussed in greater detail below.

<FIG> depicts communication <NUM> for sidelink control information indication between a remote UE <NUM> and a relay UE <NUM>, according to embodiments of the disclosure. The remote UE <NUM> may be one embodiment of a remote unit <NUM>, while the relay UE <NUM> may be one embodiment of a relay unit <NUM>. The remote UE <NUM> and relay UE <NUM> communicate using sidelink communication over a D2D connection. Here, the sidelink communication includes a plurality of subframes <NUM>-<NUM>. As depicted, a first portion of the subframes are Relay UE Transmission subframes and a second portions of the subframes are Relay UE Reception subframes. During a Relay UE Transmission subframe, the relay UE <NUM> is scheduled to transmit data, signaling, feedback information, and the like to one or more remote UEs <NUM>. During a Relay UE Reception subframe, the relay UE <NUM> is scheduled to receive data, signaling, feedback information, and the like from the one or more remote UEs.

The number and location of the Relay UE Transmission subframes and Relay UE Reception subframes forms the transmission-reception pattern <NUM> for the sidelink communication. In order for the remote UE <NUM> and the relay UE <NUM> to successfully communicate each must know the transmission-reception pattern <NUM>. In the depicted embodiment, the relay UE <NUM> generates the transmission-reception pattern <NUM> and transmits an indicator of the transmission-reception pattern (item <NUM>) to the remote UE <NUM>.

In this case, when the relay UE <NUM> transmits a data transmission, the relay UE <NUM> needs to determine and generate an indicator <NUM> of the transmission-reception pattern <NUM> so that the remote UE <NUM> can identify at least one Relay UE Reception subframe, as shown in <FIG>. The remote UE <NUM> provides feedback of the decoding status (e.g., HARQ ACK/NACK) of one or more data transmission(s) it receives from the relay UE <NUM>.

First, the relay UE <NUM> determines the transmission-reception pattern <NUM> for sidelink communication between one or more remote UE(s) <NUM>. After determining the transmission-reception pattern <NUM>, the relay UE <NUM> generates an indicator <NUM> of the transmission-reception pattern. In some embodiments, the indicator <NUM> of the transmission-reception pattern is transmitted in a sidelink control information ("SCI") message.

In some embodiments, the relay UE <NUM> determines the transmission-reception pattern <NUM> by selecting from a set of predefined patterns. <FIG> shows a table of eight different predefined patterns. In certain embodiments, the transmission-reception pattern <NUM> is selected based on the ratio of payload size to be transmitted between relay UE <NUM> and remote UE <NUM> on sidelink.

The payload size of the relay UE <NUM> is based on the payload size to be transmitted from the relay UE <NUM> to the remote UE <NUM>. The payload size of the remote UE <NUM> is based on the payload size to be transmitted from the remote UE <NUM> to the relay UE <NUM>. The information of payload (size) of the remote UE <NUM> may be obtained via a SR (scheduling request) or a BSR (Buffer Status Report) received by an eNB or relay UE <NUM>.

The buffer status of the relay UE <NUM> is used for the relay UE <NUM> to determine the number of relay UE transmission subframes (e.g., the number of reception subframes for the remote UE <NUM>). The information of buffer status of the relay UE <NUM> is based on triggered traffic on the relay UE <NUM> side. The buffer status report ("BSR") of the remote UE <NUM> is based on the triggered traffic on the remote UE <NUM> side. The remote UE <NUM> reports the BSR to the relay UE <NUM> in a BSR MAC control element (e.g., transmitted in UL data channel for legacy UE to eNB transmission). After receiving the BSR of the remote UE <NUM>, the relay UE <NUM> may determine the number of relay UE reception subframe (e.g., the number of transmission subframes for the remote UE).

In certain embodiments, the transmission-reception pattern <NUM> is generated by the relay UE <NUM> and may or may not conform to one of the predefined patterns. Here, the generated transmission-reception pattern <NUM> may also be based on the ratio of payload size to be transmitted between relay UE <NUM> and remote UE <NUM> on sidelink.

As depicted in <FIG>, the relay UE <NUM> transmits data to the remote UE <NUM> in four subframes <NUM>-<NUM> and the remote UE <NUM> receives the data during these subframes. Here, the remote UE <NUM> is to respond to the four subframes transmissions in one subframe. In the depicted embodiment, the payload size ratio is <NUM>:<NUM> and the transmission-reception pattern <NUM> is four transmission subframes on relay UE <NUM> side to one reception subframe on relay UE <NUM> side. In certain embodiments, the transmission-reception pattern <NUM> may be represented in bitmap manner, e.g., <NUM> bits (<NUM>), in sidelink control information. Here, a value of "<NUM>" in the bitmap indicates that the subframe is a Relay UE Transmission subframe, while a value of "<NUM>" indicates that the subframe is a Relay UE Reception subframe.

While the embodiments of <FIG> depict the relay UE <NUM> determining the transmission-reception pattern <NUM>, in other embodiments the transmission-reception pattern <NUM> may be generated by the eNB, e.g., based on the ratio of payload size to be transmitted between relay UE <NUM> to and remote UE(s) <NUM> on sidelink. In such embodiments, the transmission-reception pattern <NUM> is then transmitted from the eNB (not shown) to the relay UE <NUM>. Alternatively, the eNB may transmit the transmission-reception pattern <NUM> to both relay UE <NUM> and remote UE(s) <NUM> by downlink control information.

In one embodiment, the indicator <NUM> of the transmission-reception pattern may be an indication of one or more next reception subframes on the relay UE <NUM> side (e.g., indicate Relay UE Reception subframes). Here, the relay UE <NUM> may determine the next one reception subframe (e.g., to receive the transmission from the remote UE <NUM>) and then the relay UE <NUM> generates an indicator of next one reception subframe pattern. For example, a <NUM>-bit value of "<NUM>" may be included in SCI to indicate that the n+<NUM> subframe is used for relay UE <NUM> reception (i.e., receiving and detecting remote UE <NUM> transmission). Generally, the indicator of a next reception subframe must point to a subframe far enough ahead in time for the remote UE <NUM> to process the SCI and switch to transmission mode.

In the depicted embodiment, the relay UE <NUM> may send an indicator with a value of "<NUM>" (binary "<NUM>") during subframe #<NUM> (subframe <NUM>) to indicate that the next relay UE reception subframe is n+<NUM> subframes away (e.g., the next UE reception subframe is subframe #<NUM>). Similarly, in subframe #<NUM> (subframe <NUM>) the indicator may have a value of "<NUM>" (binary "<NUM>") and in subframe #<NUM> (subframe <NUM>) the indicator may have a value of "<NUM>" (binary "<NUM>"), each indicator pointing to the subframe #<NUM> (subframe <NUM>) as the next relay UE reception subframe.

However, in subframe #<NUM> (subframe <NUM>), there is insufficient processing time to point to the subframe #<NUM> (subframe <NUM>). Thus, in subframe #<NUM> (subframe <NUM>) the indicator may have a value of "<NUM>" (binary "<NUM>") to indicate that the next relay UE reception subframe is n+<NUM> subframes away (e.g., the next UE reception subframe is subframe #<NUM>). In another embodiment, the indicator <NUM> of the transmission-reception pattern may be an indication of one or more next transmission subframes on the relay UE <NUM> side (e.g., indicate Relay UE Transmission subframes).

<FIG> depicts a table <NUM> with predetermined transmission-reception patterns <NUM>. Here, 'T' represents the transmission subframe(s) on relay UE <NUM> side and 'R' represents the reception subframe(s) on relay UE <NUM> side). The table <NUM> includes a transmission-to-reception configuration <NUM>. Each transmission-to-reception configuration <NUM> corresponds to one of the predetermined transmission-reception patterns <NUM>. The relay UE <NUM> may send, as the indicator <NUM>, a binary value corresponding to the transmission-to-reception configuration <NUM>.

The table <NUM> also includes transmission-to-reception switch-point periodicity information <NUM> when indicates a periodicity with which a predetermined transmission-reception pattern <NUM> switches from relay UE transmission to relay UE reception, and back again. For example, the transmission-reception pattern <NUM> shown in <FIG> may correspond to the transmission-to-reception configuration #<NUM> and have a transmission-to-reception switch-point periodicity of <NUM> (each subframe being <NUM> in duration).

Returning to <FIG>, the relay UE <NUM> transmits the indicator <NUM> of the transmission-reception pattern to the remote UE <NUM>. In some embodiments, the indicator <NUM> is sent in a SCI message. The indicator <NUM> of pattern may be represented by a plurality of bits (e.g., <NUM>, <NUM> or <NUM> bits) in the SCI. As a first example, a bitmap indicator <NUM> of the transmission-reception pattern may use <NUM> bits to represent the transmission-reception pattern <NUM> in the following <NUM> subframes. As mentioned above, a '<NUM>' may be used to represent a transmission subframe and a '<NUM>' may be used to represent a reception subframe. Using this convention, the transmission-reception pattern <NUM> may be indicated using the bitmap "<NUM>".

In another embodiment, the indicator <NUM> of the transmission-reception pattern may use one or more bits to indicate the next one reception subframe (or alternative the next one transmission subframe). As mentioned above, a four-bit indicator <NUM> of "<NUM>" may be used to indicate that the n+<NUM> subframe is used for relay UE <NUM> reception (e.g., the remote UE <NUM> may transmit data or feedback information in this subframe). Alternatively, a three-bit indicator <NUM> of "<NUM>" may be used to indicate that the n+<NUM> subframe is to be used for relay UE transmission (e.g., the remote UE <NUM> is to receive data or feedback information in this subframe).

In certain embodiments, the indicator <NUM> may include one or more bits representing one of a set of pre-defined transmission-reception patterns <NUM>. For example, a three-bit indicator <NUM> may be used to represent one of a set of pre-defined pattern configurations in <FIG>. Specifically, an indicator <NUM> of '<NUM>' indicates the transmission-to-reception configuration #<NUM> where the first nine subframes (subframe <NUM>-<NUM>) in one frame (<NUM>) are used for relay UE <NUM> transmission and the last subframe (subframe <NUM>) is used for relay UE <NUM> reception.

In certain embodiments, the indicator <NUM> may include additional information. In a first example, an indicator of scheduling assignment ("SA") may indicate a time/frequency resource of feedback information. In a second example, an indicator of SA may indicate a time offset and/or frequency offset based on the transmission resource of the relay UE <NUM>. In a third example, an indicator of SA may indicate the time offset only. Here, the frequency resource is same as relay UE <NUM> transmission (SA and/or data) resource. In a fourth example, the time offset is preconfigured or fixed (e.g., n+<NUM>) and the frequency resource is same as the relay UE <NUM> transmission (SA and/or data) resource. In a fifth example, the indicator <NUM> may indicate a preconfigured or fixed time/frequency offset for resource hopping.

As discussed above, the relay UE <NUM> may send the indicator <NUM> of the transmission-reception pattern in a SCI message. Besides the indicator <NUM> of the transmission-reception pattern, the SCI transmitted from relay UE <NUM> to remote UE <NUM> may include a flag for scheduling assignment function differentiation. The SA function differentiation flag may be a <NUM>- or <NUM>-bit flag used to differentiate a SA is used to indicate its associated data transmission from a feedback ACK/NACK information transmission. The SA function differentiation flag aids the remote UE <NUM> in interpreting the SCI message.

In some embodiments, the SA function differentiation flag is a <NUM>-bit flag that indicates whether this SCI includes only an indication of feedback information transmission or whether it includes both an indication of data transmission and an indication of feedback information transmission. For example, a value of '<NUM>' may indicate that the SCI message contains an indication of feedback information, while a value of '<NUM>' may indicate that this SCI message include both an indication of data transmission and the indication of feedback information. Alternatively, a value of '<NUM>' may indicate that this SCI includes only an indication of feedback information, while a value of '<NUM>' may indicate that this SCI includes both an indication of data transmission and an indication of feedback information. The SA function differentiation flag is further explained with reference to <FIG>.

<FIG> depicts communication <NUM> for sidelink control information indication between the remote UE <NUM> and the relay UE <NUM>, according to embodiments of the disclosure. Note that the remote UE <NUM> and the relay UE <NUM> communicate over sidelink using a transmission-reception pattern <NUM> where the subframe <NUM> (subframe #<NUM>) is a Relay UE Reception Subframe and the subframes <NUM>-<NUM> are Relay UE Transmission Subframes.

As depicted, the relay UE <NUM> receives a data transmission from the remote UE <NUM> in subframe #<NUM> (subframe <NUM>) and attempts to transmit feedback information (e.g., HARQ feedback) corresponding to subframe #<NUM> (subframe <NUM>) in subframe #<NUM> (relay UE <NUM> transmission subframe). However, the remote UE <NUM> does not know a priori (e.g., it cannot foresee) whether the relay UE <NUM> has data to be transmitted in subframe #<NUM> to remote UE <NUM> or whether the relay UE <NUM> only has feedback information to transmit. Here, the SA function differentiation flag is included in SCI transmitted by the relay UE <NUM> so that the remote UE <NUM> is able to determine whether the SCI transmitted in subframe #<NUM> includes an indication of feedback information transmission only or whether this SCI includes both an indication of data transmission and an indication of feedback information.

In certain embodiments, the SA function differentiation flag may be a <NUM>-bit flag to indicate whether this sidelink control information includes an indication of data transmission or whether this sidelink control information includes ACK/NACK feedback information. In such embodiments, the SCI will not have both an indication of data transmission and ACK/NACK feedback information. For example, a value of '<NUM>' may indicate that this SCI includes an indication of data transmission only, while a value of '<NUM>' may indicate that this SCI includes an indication of feedback information only. Alternatively, a value of '<NUM>' may indicate that this SCI includes an indication of data transmission only, while a value of '<NUM>' may indicate that this SCI includes an indication of feedback information only.

In some embodiments, the SA function differentiation flag may be a <NUM>-bit flag that indicates whether this SCI includes an indication of data transmission only (e.g., indicated using a value of '<NUM>'), whether this SCI includes an indication of feedback information transmission only (e.g., indicates using a value of '<NUM>'), or whether this SCI includes both an indication of data transmission and feedback information transmission (e.g., indicated using a value '<NUM>'). As only three scenarios are mapped, one value of the <NUM>-bit flag (e.g., the value '<NUM>') is reserved (e.g., not to be used).

In some embodiments, the content of the SCI varies based on the SA function differentiation flag. For example, if the flag for SA function differentiation is set to indicate data transmission only, then the SCI should include the following bits to indicate data transmission relevant information: a HARQ process number (e.g., <NUM> bits); a resource allocation indication of SA associated data (e.g., 12bits); a time gap between the SA and its associated data (e.g., 4bits), a frequency resource location of SA associated data (e.g., 8bits), or some combination thereof; a modulation and coding scheme (e.g., <NUM> bits); a modulation and coding scheme of SA associated data (e.g., <NUM> bits); and a new data indicator (e.g., <NUM> bit). Note that the time gap information is used to support FDM between PSCCH/PSSCH from the system perspective, but TDM from the UE perspective.

As another example, if the flag for SA function differentiation is set to indicate ACK/NACK feedback information only, then the SCI may be modified to indicate ACK/NACK feedback relevant information. Here, the above bits of HARQ process number (3bits) and modulation and coding scheme (5bits), may be used to indicate ACK/NACK feedback in bit manner. Moreover, these <NUM> bits may represent the decoding status of <NUM> HARQ process numbers in bitmap manner, e.g., using '<NUM>' to represent ACK status and '<NUM>' to represent NACK status. Here, one or more of these bits may be used to indicate DTX status where the remote UE <NUM> did not use this HARQ process number for transmission. Accordingly, if the remote UE <NUM> transmitted the data transmission with HARQ process number, it will check the corresponding HARQ process number bit of 8bits. Here, the value of '<NUM>' can represent HARQ process #<NUM> and #<NUM> are decoded unsuccessfully or didn't used for transmission, while the other processes (e.g., #<NUM>, #<NUM>, #<NUM>, #<NUM>, #<NUM>, and #<NUM>) are decoded successfully.

As yet another example, if the flag for SA function differentiation is set to indicate both ACK/NACK feedback information and data transmission together, then the SCI may indicate both data transmission relevant information and ACK/NACK feedback relevant information. In certain embodiments, this may require new bit fields to be defined for HARQ ACK/NACK feedback in SCI. Here, a new <NUM>-bit field may be defined to convey HARQ feedback information in the manner described above.

<FIG> depicts communication <NUM> for sidelink control information indication between the remote UE <NUM> and the relay UE <NUM>, according to embodiments of the disclosure. Here, the remote UE <NUM> sends SCI and associated data to the relay UE <NUM>. To do so, the remote UE <NUM> first determines the transmission subframe for sidelink communication based on transmission and reception configuration (e.g., based on the transmission-reception pattern <NUM>). In one embodiment, the transmission and reception configuration may be received from relay UE <NUM> in sidelink control information. For example, the relay UE <NUM> may send SCI containing the indicator <NUM> of the transmission-reception pattern discussed above. In another embodiment, the transmission and reception configuration may be received from an eNB (not shown) in downlink control information. Here, the remote UE <NUM> determines to transmit SCI containing an indicator of feedback information and an indicator of associated data in subframe <NUM> ("Subframe #<NUM>).

Next, the remote UE <NUM> generates an indicator of HARQ feedback information based on the decoding status of each relay UE <NUM> transmission subframe. As discussed above, the indicator of HARQ feedback information may be a bitmap (e.g., <NUM>-bit bitmap), e.g., using '<NUM>' to represent ACK status and '<NUM>' to represent NACK status. Because the relay UE <NUM> cannot know ahead of time whether the remote UE <NUM> will transmit feedback information, an indicator of data transmission, or both feedback information and an indicator of data transmission in the SCI of Subframe #<NUM> (subframe <NUM>), the generates a flag for SA function differentiation. Here, the SA function differentiation flag generated by the remote UE <NUM> is substantially as that generated by the relay UE <NUM> described above.

Because there is an associated data transmission (e.g., the remote UE <NUM> transmits data on same subframe), the remote UE <NUM> generates the additional data transmission relevant information in SCI as discussed above. Then in Subframe #<NUM>, the remote UE <NUM> transmits the indicator <NUM> of (HARQ) feedback information and indication of associated data transmission in SCI. Here, the remote UE <NUM> transmits the associated data using the sidelink data channel.

In some embodiments, the remote UE <NUM> and/or the relay UE <NUM> may reuse the SCI format <NUM> when sending the above described indicators in SCI. Here, certain bit fields of the SCI format <NUM> are replaces with the above described indicators, requiring a receiving UE to reinterpret the SCI format <NUM> in order to receive the indicators.

Generally, the SCI format <NUM> contains <NUM> bits of priority information, <NUM> bits of resource reservation, a system-specific number of bits of frequency resource location of initial transmission and retransmission (e.g., using <MAT> bits, where <MAT> refers to the number of subchannels allocated for sidelink communication), <NUM> bits of time gap information (time gap between initial transmission and retransmission), <NUM> bits of modulation and coding scheme information, <NUM> bit for a retransmission index, and a balance of reserved information bits so that the size of the SCI format <NUM> message is <NUM>-bits in total (the reserved bits are typically set to '<NUM>').

In order to reuse the SCI format <NUM> message to indicate a transmission-reception pattern, HARQ ACK/NACK feedback information, the SA function differentiation flag, and other information discussed above, one or more bit fields may be used to carry new information. In some embodiments, the <NUM> bits of priority information may be used to represent the HARQ process number (a <NUM>-bit value) and the retransmission index may be used to represent the new data indicator. In certain embodiments, the <NUM> resource reservation bits may be used to indicate the transmission-reception pattern. Where the transmission-reception pattern can be represented with <NUM> bits, the remaining resource reservation bit may be used to represent the SA function differentiation flag. In other embodiments, the reserved information bits may be used to indicate the transmission-reception pattern and SA function differentiation flag.

In some embodiments, the priority bits and modulation and coding scheme bits may be used to represent the decoding status (HARQ ACK/NACK) of <NUM> HARQ process number in bitmap manner as discussed above. Additionally (or alternatively) bits of the reserved information bits may be used to indicate the HARQ ACK/NACK feedback indication.

<FIG> depicts one embodiment of a remote UE apparatus <NUM> that may be used for sidelink control information indication, according to embodiments of the disclosure. The remote UE apparatus <NUM> may be one embodiment of the remote unit <NUM> and/or the remote UE <NUM>. Furthermore, the remote UE apparatus <NUM> includes 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 touchscreen. In certain embodiments, the remote unit <NUM> may not include any input device <NUM> and/or display <NUM>.

The transmitter <NUM> and receiver <NUM> are used to communicate with a relay UE using sidelink communication. Here, and according to the invention, the sidelink communication is defined within preconfigured sidelink resource pools (PSCCH/PSSCH). Multiple pools can be configured by eNB for sidelink operation. In some embodiments, the sidelink communication uses frequency-division multiplexing ("FDM") between PSCCH and PSSCH, from both a UE and system perspective. In other embodiments, the sidelink communication uses FDM between PSCCH and PSSCH from the system perspective, but uses time-division multiplexing ("TDM") from the UE perspective.

In some embodiments, the receiver <NUM> receives an indicator of a transmission-reception pattern in a first control information message. The receiver <NUM> may also receive an indicator of scheduling assignment transmitted in the first control information message and associated data transmitted in a data message from a relay unit. In response to receiving one or more data processes (e.g., HARQ processes), and according to the invention, the processor <NUM> generates an indicator of hybrid automatic repeat request ("HARQ") feedback information. The processor <NUM> also determines a transmission subframe of the apparatus based on the received indicator of a transmission-reception pattern. The processor <NUM> may then control the transmitter <NUM> to transmit the indicator of HARQ feedback information to the relay unit in a second control information message on a remote unit transmission subframe determined from the transmission-reception pattern.

In some embodiments, receiving the indicator of the transmission-reception pattern includes the receiving a SCI format <NUM> message and reinterpreting the SCI format <NUM> message to determine the indicator of the transmission-reception pattern. In one embodiment, receiving the indicator of the transmission-reception pattern includes receiving the indicator of the transmission-reception pattern from the relay unit. In another embodiment, receiving the indicator of the transmission-reception pattern includes receiving the indicator of the transmission-reception pattern from a base unit.

In certain embodiments, the indicator of the transmission-reception pattern may indicate a particular pattern selected from a plurality of predetermined patterns. In one embodiment, the indicator of the transmission-reception pattern comprises a bitmap representing at least one transmission subframe and at least one reception subframe in the transmission-reception pattern. According to the invention, the indicator of the transmission-reception pattern is an offset value for instance pointing to a next reception subframe in the transmission-reception pattern. In yet another embodiment, the indicator of the transmission-reception pattern is an offset value pointing to a next transmission subframe in the transmission-reception pattern.

In certain embodiments, the second control information message includes a scheduling assignment ("SA") function differentiation flag that indicates whether the second control information message includes HARQ feedback information and whether a data transmission is associated with the second control information message. Additionally, the second control information message may also include a data offset indicating a time offset between the second control information message and the associated data transmission.

In some embodiments, the memory <NUM> stores data relating to sidelink control information indication, for example storing transmission-reception patterns, indicators, feedback information, and the like. In some embodiments, the memory <NUM> also stores program code and related data, such as an operating system or other controller algorithms operating on the remote unit <NUM> and one or more software applications.

The transmitter <NUM> and receiver <NUM> operate under the control of the processor <NUM> to transmit messages, data, and other signals and also to receive messages, data, and other signals. For example, the processor <NUM> may selectively activate the transmitter <NUM> or receiver <NUM> (or portions thereof) at particular times in order to send and/or receive messages. The remote UE apparatus <NUM> may include one or more transmitters <NUM> and one or more receivers <NUM> for communicating with the relay UE <NUM> (or relay UE <NUM>).

<FIG> depicts one embodiment of a relay UE apparatus <NUM> that may be used for sidelink control information indication, according to embodiments of the disclosure. The relay UE apparatus <NUM> may be one embodiment of the relay unit <NUM> and/or the relay UE <NUM>. Furthermore, the relay UE apparatus <NUM> includes 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 touchscreen. In certain embodiments, the remote unit <NUM> may not include any input device <NUM> and/or display <NUM>.

The transmitter <NUM> and receiver <NUM> are used to communicate with a relay UE using sidelink communication. Here, the sidelink communication is defined within preconfigured sidelink resource pools (PSCCH/PSSCH). Multiple pools can be configured by eNB for sidelink operation. In some embodiments, the sidelink communication uses frequency-division multiplexing ("FDM") between PSCCH and PSSCH, from both a UE and system perspective. In other embodiments, the sidelink communication uses FDM between PSCCH and PSSCH from the system perspective, but uses time-division multiplexing ("TDM") from the UE perspective.

In some embodiments, the receiver <NUM> receives a second control information message from a remote unit over sidelink communication. Here, the second control information message is in response to the remote unit receiving one or more data processes scheduled by a first control information message from a relay unit, e.g., from the relay UE apparatus <NUM>. The processor <NUM> determines a transmission-reception pattern for the sidelink communication between the relay UE apparatus <NUM> and the remote UE. The processor <NUM> also generates an indicator of the determined transmission-reception pattern. The processor <NUM> may then control the transmitter <NUM> to transmit the indicator of the determined transmission-reception pattern to the remote unit in a third control information message. In one embodiment, the first control information message, the second control information message, and the third control information message are transmitted in a same type of control channel (e.g., PSCCH).

In certain embodiments, the processor <NUM> determines the transmission-reception pattern comprises by determining a ratio of transmission payload to reception payload based on a buffer status of relay unit and/or a buffer status report of one or more remote units. The processor <NUM> may then generate the transmission-reception pattern based on one or more of: the ratio, the buffer status of relay unit, and the buffer status report of one or more remote units.

In one embodiment, the indicator of the determined transmission-reception pattern comprises a bitmap representing at least one transmission subframe and at least one reception subframe in the generated transmission-reception pattern. In another embodiment, the indicator of the determined transmission-reception pattern is an offset value pointing to a next reception subframe in the generated transmission-reception pattern. In yet another embodiment, the indicator of the determined transmission-reception pattern is an offset value pointing to a next transmission subframe in the generated transmission-reception pattern.

In certain embodiments, the processor <NUM> determines the transmission-reception pattern comprises by determining a ratio of transmission payload to reception payload based on a buffer status of relay unit and/or a buffer status report of one or more remote units. The processor <NUM> may then the transmission-reception pattern from a plurality of predetermined patterns based on one or more of: the ratio, the buffer status of relay unit, and the buffer status report of one or more remote units. Here, the indicator of the determined transmission-reception pattern may be a plurality of bits representing the selected transmission-reception pattern. For example, specific bit values may be mapped to specific patterns among the plurality of predetermined patterns.

In some embodiments, third control information message includes an indicator of scheduling assignment ("SA") function differentiation flag. Here, the SA function differentiation flag may indicate whether the third control information message includes hybrid automatic repeat request ("HARQ") feedback information. Where the third control information message includes HARQ feedback information, the third control information message may contain a bitmap representing HARQ feedback information corresponding to one or more HARQ processes.

In certain embodiments, the third control information message includes an indicator of scheduling assignment. Here, the indicator of scheduling assignment indicating an associated data transmission. In further embodiments, the third control information message may include a data offset indicating a time offset between the second SCI message and the associated data transmission.

In some embodiments, generating an indicator of the determined transmission-reception pattern comprises the processor <NUM> generating a SCI format <NUM> message to be reinterpreted by the remote UE to indicate the determined transmission-reception pattern. In such embodiments, the processor <NUM> may modify one or more bit fields of the SCI format <NUM> message to indicate the transmission-reception pattern.

In certain embodiments, the receiver <NUM> further receives a fourth control information message from the remote UE. Here, the fourth control information message may include an indicator of whether the fourth control information message contains ("HARQ") feedback information. The fourth control information message may also include an indicator of whether the fourth control information message is associated with a data transmission from the remote UE.

In some embodiments, the memory <NUM> stores data relating to sidelink control information indication, for example storing transmission-reception patterns, indicators, feedback information, and the like. In certain embodiments, the memory <NUM> also stores program code and related data, such as an operating system or other controller algorithms operating on the relay UE apparatus <NUM> and one or more software applications.

The transmitter <NUM> and receiver <NUM> operate under the control of the processor <NUM> to transmit messages, data, and other signals and also to receive messages, data, and other signals. For example, the processor <NUM> may selectively activate the transmitter <NUM> or receiver <NUM> (or portions thereof) at particular times in order to send and/or receive messages. The relay UE apparatus <NUM> may include one or more transmitters <NUM> and one or more receivers <NUM> for communicating with a remote UE <NUM> and/or a base unit <NUM> of a mobile communication network.

<FIG> depicts a method <NUM> for sidelink control information indication, according to embodiments of the disclosure. In some embodiments, the method <NUM> is performed by an apparatus, such as the relay unit <NUM>, the relay UE <NUM>, and/or relay UE apparatus <NUM>. In certain embodiments, the method <NUM> may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method <NUM> begins and receives <NUM> second control information message from a remote unit over sidelink communication. Here, the second control information message is in response to the remote unit receiving one or more data processes scheduled by a first control information message from a relay unit. In some embodiments, the first control information message includes a transmission-reception pattern, wherein the second control information message is received during a reception period of the transmission-reception pattern.

The method <NUM> includes determining <NUM> a transmission-reception pattern for a remote unit using sidelink communication. In some embodiments, determining <NUM> the transmission-reception pattern includes determining a ratio of transmission payload to reception payload based on a buffer status of relay unit and/or a buffer status report of one or more remote units, and further generating the transmission-reception pattern based one or more of: on the ratio, the buffer status of relay unit, and the buffer status report of one or more remote units. In certain embodiments, determining the transmission-reception pattern includes selecting the transmission-reception pattern from a plurality of predetermined patterns based one or more of: on the ratio, the buffer status of relay unit, and the buffer status report of one or more remote units, wherein the indicator of the determined transmission-reception pattern comprises a plurality of bits representing the selected transmission-reception pattern.

The method <NUM> includes generating <NUM> an indicator of the determined transmission-reception pattern. In some embodiments, generating <NUM> an indicator of the determined transmission-reception pattern includes generating a SCI format <NUM> message to be reinterpreted by the remote unit to indicate the determined transmission-reception pattern.

In one embodiment, the indicator of the determined transmission-reception pattern comprises a bitmap representing at least one transmission subframe and at least one reception subframe in the generated transmission-reception pattern. In another embodiment, the indicator of the determined transmission-reception pattern is an offset value pointing to a next reception subframe in the generated transmission-reception pattern. In yet another embodiment, the indicator of the determined transmission-reception pattern is an offset value pointing to a next transmission subframe in the generated transmission-reception pattern. Where the transmission-reception pattern is selected from a plurality of predetermined patterns, the indicator of the determined transmission-reception pattern may be a plurality of bits representing the selected transmission-reception pattern.

The method <NUM> includes transmitting <NUM> the indicator to the remote unit in a third control information message. In one embodiment, the first control information message, the second control information message, and the third control information message are transmitted in a same type of control channel (e.g., PSCCH). In certain embodiments, the third control information message includes an indicator of scheduling assignment ("SA") function differentiation flag, the SA function differentiation flag indicating that the third control information message includes hybrid automatic repeat request ("HARQ") feedback information. Here, the third control information message may include a bitmap representing the HARQ feedback information in response to one or more HARQ process.

In some embodiments, the third control information message includes an indicator of scheduling assignment, the indicator of scheduling assignment indicating that a data transmission is associated with the third control information message. Here, the third control information message may further include a data offset indicating a time offset between the third control information message and the associated data transmission. In certain embodiments, the remote unit sends a fourth control information message in response to the transmitting <NUM> of the indicator to the remote unit. Here, the fourth control information message includes an indicator of whether the fourth control information message contains ("HARQ") feedback information. In further embodiments, the fourth control information message may include an indicator of whether the fourth control information message is associated with a data transmission from the remote unit. The method <NUM> ends.

<FIG> depicts a method <NUM> for sidelink control information indication, according to embodiments of the disclosure. In some embodiments, the method <NUM> is performed by an apparatus, such as the remote unit <NUM>, the remote UE <NUM>, and/or the remote UE apparatus <NUM>. In certain embodiments, the method <NUM> may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method <NUM> begins and receives <NUM> an indicator of a transmission-reception pattern in a first control information message. In one embodiment, the first control information message is a sidelink control information ("SCI") message. In another embodiment, the first control information message is a downlink control information ("DCI") message.

The method <NUM> includes receiving <NUM> an indicator of scheduling assignment transmitted in the first control information message and associated data transmitted in a data channel from a relay unit. In one embodiment, the associated data is received via a sidelink data message. In some embodiments, receiving <NUM> the indicator of the transmission-reception pattern comprises receiving a SCI format <NUM> message and reinterpreting the SCI format <NUM> message to determine the indicator of the transmission-reception pattern. In one embodiment, receiving <NUM> the indicator of the transmission-reception pattern comprises receiving the indicator of the transmission-reception pattern from the relay unit. In another embodiment, receiving <NUM> the indicator of the transmission-reception pattern comprises receiving the indicator of the transmission-reception pattern from a base unit.

The method <NUM> includes generating <NUM> an indicator of hybrid automatic repeat request ("HARQ") feedback information in response to the received one or more data processes. In one embodiment, the one or more data processes are one or more HARQ processes. In some embodiments, the indicator of the transmission-reception pattern indicates a particular pattern selected from a plurality of predetermined patterns. In one embodiment, the indicator of the transmission-reception pattern comprises a bitmap representing at least one transmission subframe and at least one reception subframe in the transmission-reception pattern. In another embodiment, the indicator of the transmission-reception pattern is an offset value pointing to a next reception subframe in the transmission-reception pattern. In yet another embodiment, the indicator of the transmission-reception pattern is an offset value pointing to a next transmission subframe in the transmission-reception pattern.

The method <NUM> includes determining <NUM> a transmission subframe of the apparatus based on the received indicator of a transmission-reception pattern. The method <NUM> includes transmitting <NUM> the indicator of HARQ feedback information to the relay unit in a second control information message on a transmission subframe of remote unit determined from the transmission-reception pattern. In one embodiment, the second control information message is a SCI message. In some embodiments, the second control information message includes a scheduling assignment ("SA") function differentiation flag that indicates whether the second control information message includes HARQ feedback information and whether a data transmission is associated with the second control information message. In certain embodiments, the second control information message further includes a data offset indicating a time offset between the second control information message and the associated data transmission. The method <NUM> ends.

Claim 1:
A method (<NUM>) performed by a first user equipment, the method comprising:
receiving (<NUM>) a second control information message from a second user equipment over sidelink communication, wherein the second control information message is in response to the second user equipment receiving one or more data processes scheduled by a first control information message from the first user equipment;
determining (<NUM>) a time offset for hybrid automatic repeat request, HARQ, feedback information for the sidelink communication, wherein the time offset is (pre-)configured per sidelink resource pool;
generating (<NUM>) an indicator of the determined time offset; and
transmitting (<NUM>) the indicator of the determined time offset to the second user equipment in a third control information message.