Method and apparatus for uplink power control

Abstract

The present invention relates to methods and apparatus for uplink power control. A method and apparatus schedules uplink transmissions with reduced delay. A first uplink transmission sent using a first transmission power may be received in a subframe. At least a second uplink transmission sent using a second transmission power may be received in the subframe, wherein the first uplink transmission and the second uplink transmission overlap in time for at least one symbol duration.

Description

[0001] This application is a divisional application of an application which entered the Chinese national phase on September 21, 2018, with PCT application number PCT / US2017 / 023918, international application date March 23, 2017, Chinese application number 201780019097.2, and invention name “Method and apparatus for uplink power control when uplink transmission overlaps at least one symbol duration in time”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to Motorola Mobility Docket No. MM02047, U.S. Provisional Application No. 62 / 317,149, filed on April 1, 2016, entitled “Method and Apparatus for Scheduling Uplink Transmissions with Reduced Latency”; and is related to Motorola Mobility Docket No. MM02049, entitled “Method and Apparatus for Scheduling Uplink Transmissions with Reduced Latency”, Motorola Mobility Docket No. MM02050, entitled “Method and Apparatus for Scheduling Uplink Transmissions with Reduced Latency”. The present application's respective applications, including, without limitation, those filed on the same day and jointly assigned to the assignee of the present application, are hereby incorporated by reference into this application, along with Motorola Mobility's respective applications having case number MM02047 and titled "Method and apparatus for scheduling uplink transmissions with reduced time delay", and Motorola Mobility's respective applications having case number MM02047 and titled "Method and apparatus for scheduling uplink transmissions with reduced time delay", and Motorola Mobility's respective applications having case number MM02052 and titled "Method and apparatus for scheduling uplink transmissions with reduced time delay", are hereby incorporated by reference into this application, along with, without limitation, those filed on the same day and jointly assigned to the assignee of the present application, and are hereby incorporated by reference into this application, along with, without limitation, those filed on the same day and jointly assigned to the assignee of the present application, and are hereby incorporated by reference into this application, along with, without limitation, those filed on the same day and jointly assigned to the assignee of the present application, and are hereby incorporated by reference into this application, Technical Field

[0004] The present disclosure is directed to a method and apparatus for scheduling uplink transmissions with reduced latency. More specifically, the present disclosure is directed to wireless communication device transmissions using shortened transmission time intervals. Background Art

[0005] Currently, in the Long Term Evolution (LTE) communication system, time-frequency resources are divided into subframes, where each 1ms subframe has two 0.5ms time slots, and each time slot has seven single carrier frequency division multiple access (SCFDMA) symbols for uplink transmission in the time domain. In the frequency domain, the resources within the time slot are divided into physical resource blocks (PRBs), where each resource block spans 12 subcarriers.

[0006] In current LTE systems, a 1ms minimum transmission time interval (TTI) is used to schedule user equipment (UE) uplink data. Within each scheduled TTI, the UE sends data through the physical uplink shared channel (PUSCH) in the PRB pair indicated by the uplink grant, which schedules the data transmission to the UE. Each PRB pair includes two PRBs, one in each time slot. For FDD systems, if an uplink grant is received in subframe n, the UE sends PUSCH in subframe n+4 in response to the grant, and looks for ACK / NACK corresponding to the transmission in subframe n+8. If NACK is indicated, the UE will retransmit in subframe n+12, resulting in a HARQ round-trip delay of 8ms. TDD systems typically have similar or longer round-trip delays. This results in delays in the transmission and reception of delayed communication signals.

[0007] Therefore, there is a need for a method and apparatus for scheduling uplink transmission with reduced latency. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to describe the manner in which the advantages and features of the present disclosure can be obtained, the description of the present disclosure is presented by reference to the specific embodiments of the present disclosure shown in the accompanying drawings. These drawings depict only example embodiments of the present disclosure and therefore should not be considered to limit its scope. The drawings may have been simplified for clarity and are not necessarily drawn to scale.

[0009] Figure 1 is an example illustration of a system according to a possible embodiment;

[0010] Figure 2 is an example diagram showing subframes for HARQ-ACK feedback in uplink subframe n+4 for downlink rTTI in DL subframe n and for downlink sTTI in DL subframe n+2 according to a possible embodiment;

[0011] Figure 3 is an example illustration of HARQ-ACK feedback in uplink subframe n+4 for downlink sTTI-1 in DL subframe n+2 and sTTI-2 in DL subframe n+2 according to a possible embodiment;

[0012] Figure 4 is an example diagram of a subframe showing an example of PUCCH resource mapping for a first case with rTTI and sTTI according to a possible embodiment;

[0013] Figure 5 is an example diagram of a subframe showing an example of PUCCH resource mapping for a second case with sTTI-1 and sTTI-2 according to a possible embodiment;

[0014] Figure 6 is an example subframe showing uplink of simultaneous PUSCH on sTTI and rTTI with common RS symbol position and separate DFT precoding according to a possible embodiment;

[0015] Figure 7 is an example subframe showing uplink of simultaneous PUSCH on sTTI and rTTI with common RS symbol position and separate DFT precoding according to a possible embodiment;

[0016] Figure 8 is an example illustration of device-to-device operations according to possible embodiments;

[0017] Fig. 9 is an example illustration of a 1 ms device-to-device subframe with 2 symbols UL data in symbols 9-10 according to a possible embodiment;

[0018] Fig.10 is an example flow chart illustrating the operation of the device according to possible embodiments; and

[0019] Fig.11 is an example block diagram of an apparatus according to a possible embodiment. DETAILED DESCRIPTION

[0020] Embodiments provide methods and apparatus for scheduling uplink transmissions with reduced latency. According to possible embodiments, a first transmission power of a first uplink transmission may be determined at a device based on a first set of power control parameters configured by a higher layer associated with a first TTI length. The higher layer may be higher than the physical layer. The first uplink transmission may span the first TTI length. The first TTI length may include a first number of symbols. A second transmission power of a second uplink transmission may be determined based on a second set of power control parameters configured by a higher layer associated with a second TTI length. The second uplink transmission may span the second TTI length. The second TTI length may include a second number of symbols. The second number may be different from the first number. The first uplink transmission may be sent in a subframe using the first transmission power. At least a second uplink transmission may be sent in a subframe using the second transmission power. The first uplink transmission and the second uplink transmission may overlap in time for at least one symbol duration.

[0021] Figure 11 is an example illustration of a system 100 according to a possible embodiment. The system 100 can include a wireless communication device 110, a base station 120, and a network 130. The wireless communication device 110 can be a user equipment (UE), such as a wireless terminal, a portable wireless communication device, a smart phone, a cellular phone, a flip phone, a personal digital assistant, a device with a user identification module, a personal computer, a selective call receiver, a tablet computer, a laptop computer, or any other device capable of sending and receiving communication signals on a wireless network. The base station 120 can be an enhanced node B, an access point, another device, or any other element capable of providing access between a wireless communication device and a network.

[0022] The network 130 can include any type of network capable of sending and receiving wireless communication signals. For example, the network 130 can include a wireless communication network, a cellular telephone network, a network based on time division multiple access (TDMA), a network based on code division multiple access (CDMA), a network based on orthogonal frequency division multiple access (OFDMA), a long term evolution (LTE) network, a network based on the third generation partnership project (3GPP), a satellite communication network, a high altitude platform network, and / or other WWAN communication networks.

[0023] In operation, the transmission of UE data using a shorter minimum transmission time interval (TTI) such as shorter than 1ms can be used to reduce latency in LTE systems. Compared to current LTE systems, a shorter minimum TTI (sTTI) can allow UEs to send data using reduced latency. For example, scheduling UE transmissions on a sTTI length of 0.5ms, such as a shortened physical uplink shared channel (shortened PUSCH or sPUSCH) scheduled using a 0.5ms physical resource block (PRB) across a 1ms subframe, or scheduling UE transmissions on a sPTI length of about 140us, such as sPUSCH, using a shortened physical resource block (PRB) scheduling of two single-carrier frequency division multiple access (SC-FDMA) symbols within a time slot in a subframe, can not only reduce the time spent sending data packets, but also reduce the round-trip time of possible hybrid automatic repeat request (HARQ) retransmissions associated with the data packet. The disclosed embodiments can enable UE transmissions through shortened TTIs.

[0024] UE transmissions can be received by one or more base stations, such as eNBs, or other UEs in the communication network. When a UE transmission is received by other UEs, the transmission can also be referred to as a sidelink transmission.

[0025] For configuration of sTTI operation, at least one of two approaches can be used to support sTTI transmissions, such as transmissions based on a shortened minimum TTI length. For the first approach to supporting sTTI transmissions, the UE can be configured by a higher layer, such as a radio resource control (RRC) layer, a media access control (MAC) layer, or other higher layers, to operate in sTTI mode. The configuration can indicate a specific sTTI length. Once configured, the UE can expect to receive uplink (UL) grants only for sTTI transmissions, and can perform UE transmissions based on the configured sTTI length in response to the grant.

[0026] For the second approach for supporting sTTI transmissions, the UE can be configured by higher layers to operate in sTTI mode. The configuration can indicate a specific sTTI length. Once configured, in addition to receiving grants for scheduling UL transmissions with a regular TTI (rTTI) length such as the TTI length used in current LTE systems, the UE can also expect the UE to receive grants for scheduling UL transmissions with the configured sTTI length. As an example of TTI length in current LTE systems, the PUSCH / transmission and associated demodulation reference signal (DMRS) can continuously span the first 13 SC-FDMA symbols or all SC-FDMA symbols of a subframe. This transmission can generally be referred to as a 1ms TTI transmission or a regular TTI transmission.

[0027] The second approach can be more flexible compared to the simpler first approach. While sTTI transmissions help reduce latency, they may also require more control signaling and pilot overhead compared to conventional 1ms TTI transmissions. The second approach can provide the network with more options to weigh latency against control signaling / pilot overhead. In both approaches, the network can decide when to configure a UE with sTTI mode based on receiving an indication from the UE. The indication can be, for example, a scheduling request (SR) associated with sTTI operation or a buffer status report (BSR) indicating that there is data in the UE buffer that requires sTTI operation. According to a possible implementation, when the MAC layer is used to configure short TTI, configuration signaling can be sent in the form of an sTTI activation / deactivation MAC control element (MAC CE).

[0028] If the UE has data to send, it can request UL transmission resources using at least three different methods, such as requesting the network to send an UL grant. One method of requesting an UL grant is a method based on a scheduling request (SR). In this method, the UE can be configured with a set of physical layer SR resources by the network. When the UE has data to send, it can send a transmission on the SR resources, in response to which the network can send a grant to the UE. Each SR resource can be a physical uplink control channel (PUCCH) resource mapped to a pair of PRBs in a 1ms subframe, where each PRB occupies a 0.5ms time slot within a 1ms subframe. SR resources can occur in multiple subframes, where the SR resource set can include SR resources in all possible subframes. The subframes in which SR resources can appear can be configured by higher layers.

[0029] Another method for requesting UL grant can be a RACH-based method. In this method, if no SR resources are configured for the UE, the UE can initiate a random access procedure by sending using a physical random access channel (PRACH).

[0030] Another method for requesting UL grant is a method based on buffer status report (BSR). In this method, the UE can use a medium access control (MAC) layer message called BSR to indicate the amount of outstanding data it must send. The BSR can be carried on the physical layer using PUSCH. PUSCH can be sent using one or more PRB pairs in a subframe, where each PRB pair includes two PRBs, where each PRB can be sent in each 0.5ms slot of the subframe.

[0031] In order to send data using sTTI instead of regular TTI, the UE can request permission for sTTI transmission. One or more of the following methods can be used to enable data transmission using sTTI operation. One method of enabling data transmission using sTTI is by using different SR resources for regular and sTTI transmissions. In this method, the UE can be configured with two different sets of SR resources. The UE can use a first set of SR resources to indicate to the network that it has data that can be scheduled using regular TTI transmission. The second set of SR resources that the UE can use indicates to the network that it has data to send that requires sTTI transmission for lower latency.

[0032] A second set of SR resources can be sent on a physical channel spanning a duration of <= 0.5 ms. Each SR resource of the second set can be a shortened PUCCH resource (sPUCCH). Alternatively, each SR resource of the second set can be a shortened PUSCH (sPUSCH) resource. For this option, the UE can optionally send a buffer status report (BSR) on the SR resource. Alternatively, each SR resource of the second set can include a sounding reference signal (SRS) resource. Alternatively, each SR resource of the second set can include a demodulation reference signal (DMRS) resource.

[0033] The second set of SR resources can be mapped to a single PRB in a 0.5ms slot of a subframe. Alternatively, the SR resources can be mapped to one of 1 / 2 / 3 / 4 SCFDMA symbols of a subframe and span the entire transmission bandwidth configuration, or a subset of PRBs within the transmission bandwidth configuration. The UE can send a BSR in the second SR resource set indicating the presence of low-latency or critical data in its buffer. The BSR can also indicate the buffer size of outstanding low-latency / critical data in the UE buffer. The second SR resource set can be configured to occur more frequently than the first SR resource set.

[0034] For the case where the second resource set includes PUCCH resources, the UE is able to use a first PUCCH resource from a first higher layer configured PUCCH resource set to send an SR, which is used to indicate to the network that it has data to be sent that can be scheduled using a normal TTI transmission; and use a second PUCCH resource from a second higher layer configured PUCCH resource set to send an SR, which is used to indicate to the network that it has data to be sent that can be scheduled using an sTTI transmission. The UE is typically also able to use PUCCH resources to send HARQ-ACK in response to DL data, and is able to determine the use of PUCCH resources based on the control channel element (CCE) index of the control channel that schedules DL data transmission. If the UE has to send HARQ-ACK in a subframe and also has a pending SR for requesting a normal TTI transmission, the UE is able to use the PUCCH resources from the first higher layer configured PUCCH resource set in the subframe instead of the PUCCH resources determined from the CCE index to send the HARQ-ACK. If the UE has to send HARQ-ACK in a subframe and also has a pending SR for requesting sTTI transmission or has a pending request for both regular TTI transmission and sTTI transmission, the UE can use a PUCCH resource set from a second higher layer configuration in that subframe instead of the PUCCH resource determined from the CCE index to send HARQ-ACK. In one example, the first PUCCH resource can span a first number of symbols (e.g., 14 symbols) and the second PUCCH resource can span a second number of symbols less than the first number (e.g., 7 symbols). In another example, both the first and second PUCCH resources can span the same number of symbols.

[0035] For the case where each SR resource of the second SR resource set is a sounding reference signal (SRS) resource, the UE can be configured to transmit on regular SRS resources (such as resources on which the UE transmits for channel sounding purposes), and on SR-specific SRS resources (such as resources configured for SR transmissions on which the UE transmits for requesting UL transmission resources, such as requesting UL grants). If both regular SRS resources and SR-specific SRS resources appear in the same SC-FDMA symbol and the UE needs to send an SR, the UE can transmit on the SR-specific SRS resources and forgo transmission on the regular SRS resources. If the UE does not need to send an SR, the UE can transmit on its regular SRS resources.

[0036] For the case where each SR resource of the second SR resource set is a DMRS resource, the UE can send a DMRS using a predefined / preconfigured DMRS cyclic shift value to indicate the presence of a SR request.

[0037] Another way to be able to send data using sTTI is by using different PRACH resources to request regular and sTTI transmissions. With this method, when the UE is configured in sTTI mode of operation, the UE can be configured with two different sets of PRACH resources. The second set of PRACH resources can appear more frequently in time than the first set. The UE can use the second set of PRACH resources to send RACH preambles only when the UE has reduced latency data to send, otherwise the first set of RACH resources is used. When using the second set of RACH resources, the UE can use shorter RACH preambles, such as preambles of smaller duration, compared to preambles used for transmissions using the first set of PRACH resources, an example of which is PRACH format 4.

[0038] Another method of being able to send data using sTTI is to use a modified BSR. In this method, the UE can send a modified BSR that can be modified compared to the BSR sent by a conventional LTE UE and compared to a UE that is not configured with sTTI mode. The bits in the modified BSR can indicate that the UE has unprocessed data that needs to be sent with reduced latency. In response to the modified BSR, the network can send an UL grant to the UE to schedule UL sTTI resources. The modified BSR can include an additional bit indicating the presence of critical or low-latency data in the UE buffer, based on which the network can send an UL grant to schedule sTTI resources. For example, a BSR with a bit set to "1" can indicate the presence of critical or low-latency data that requires sTTI grant, and a BSR without an additional bit or a BSR with a bit set to "0" can indicate that sTTI grant is not required. In current LTE systems, buffer status can be indicated for 4 different logical channel groups (LCGs). For UEs configured with sTTI operation, the number of LCGs can be expanded. For example, the UE can be allowed to report the buffer status of 5 or more LCGs. The UE can report a BSR with LCG ID>=4 to indicate the presence of low-latency / critical data that requires sTTI-based transmission. The modified BSR can be configured with different BSR parameters, such as retxBSR-Timer, by a higher layer such as RRC. For example, the same retxBSR-Timer value can be set by a higher layer for both regular and low-latency data, but it can be indicated in a TTI instead of a subframe. In this case, a single indication can be used for this purpose, such as an indication of retxBSR-Timer=2, which means 2 subframes for regular data and 2 sTTIs for low-latency data. For regular and periodic BSRs, if more than one LCG has data available for transmission in the TTI in which the BSR is sent, a long BSR can be reported if a long BSR can be sent in the TTI. Otherwise, a short BSR can be reported. If the UE is configured with sTTI and a delay-tolerant packet arrives, the sTTI resources may or may not be used to send a BSR for delay-tolerant data, depending on the configuration done by higher layer signaling. The modified BSR can include bits indicating a TTI length value suitable for sending data in the UE buffer.

[0039] The downlink control information format (DCI format) used for UL grant scheduling sPUSCH transmission can be different from the DCI format used for UL grant scheduling conventional 1ms TTI PUSCH transmission. Assuming a first DCI format, such as DCI format 0 used in the current LTE system, and assuming a second DCI format, such as the new DCI format S0 for scheduling sPUSCH, a UE configured for sTTI operation mode can be configured to monitor UL grants. If the UE detects a UL grant with the first DCI format, it can send PUSCH in response to the grant. If the UE detects a UL grant with the second DCI format, it can send sPUSCH in response to the grant. The grant with the second DCI format can also optionally indicate the sTTI length. The sTTI length can be indicated by the number of SC-FDMA symbols. Alternatively, the grant with the second DCI format can indicate the number of consecutive sTTIs assigned to the UE. In some cases, the assigned sTTI can exist in more than one subframe.

[0040] The sTTI lengths for UL and DL can be the same. Alternatively, they can be different. For example, for coverage reasons, the UE can be configured with one OFDM symbol downlink (DL) sTTI and one slot (or 7 SC-FDMA symbols) UL sTTI. In this case, each DL subframe can have 14 DL sTTIs, while each UL subframe can have two UL sTTIs. One option can be to identify sTTIs based on a subframe index and a sTTI index pair, where (n, x) represents TTI x (or sTTI x) within subframe n. DL sTTIs within a given subframe can be sorted using 0, 1, 2, ..., Nsttid-1, where Nsttid can be the maximum number of possible DL sTTI durations within the subframe duration. Similarly, UL sTTIs within a given subframe can be sorted using 0, 1, 2, ..., Nsttiu-1, where Nsttiu can be the maximum number of possible UL sTTI durations within the subframe duration. After considering the minimum processing time (Tp) required for the UE to prepare for UL transmission after receiving the grant, the timing relationship between UL grant reception and UL transmission can be defined.

[0041] For example, assuming Tp = 0.5ms, Nsttid = 14 (DL sTTI length = 1 OFDM symbol), Nsttiu = 2 (UL sTTI length = 7 SC-FDMA symbols). Then, for a grant received in DL sTTI (n, 0), such as DL sTTI 0 in subframe n, the corresponding UL transmission can occur in UL sTTI (n, 1), such as UL sTTI 1 in subframe n. Similarly, for grants received in DL sTTI (n, 1), (n, 2)...(n, 6), after taking into account the processing time Tp, the corresponding UL transmission can occur in UL sTTI (n, 1), such as the first available uplink sTTI; and similarly, for grants received in DL sTTI (n, 7), (n, 8)...(n, 13), the corresponding UL transmission can occur in UL sTTI (n+1, 0).

[0042] For systems where the UL sTTI length is less than the DL sTTI length, an sTTI index parameter can be signaled in the grant to identify the specific UL sTTI to which the grant applies. The sTTI index parameter can be used to identify the sTTI index within a subframe using the approach described in the two paragraphs above. For example, assume Tp = 0.5ms, Nsttid = 2 (DL sTTI length = 7 OFDM symbols) and Nsttiu = 14 (UL sTTI length = 1 SC-FDMA symbol). For this case, the UL grant sent in DL sTTI (n, 0) can be used to schedule UL transmission in one or more of sTTI (n+1, 0) (i.e., subframe n+1 and sTTI index 0), (n+1, 1) (i.e., subframe n+1 and sTTI index 1), ... (n+1, 6) (i.e., subframe n+1 and sTTI index 1), and the UL grant sent in DL sTTI (n, 1) can be used to schedule UL transmission in one or more of sTTI (n+1, 7), (n+1, 1), ... (n+1, 13). In view of this, in addition to the implicit timing based on processing time, the bits in the UL grant can also be used to indicate to the UE a specific UL sTTI within the schedulable sTTI set (e.g., an sTTI within a given subframe). When cross-carrier scheduling is used, the TTI lengths of the UL and DL can be different. For example, a first component carrier (CC) can have a DL sTTI=0.5 ms and a second CC can have a UL sTTI=1 SC-FDMA symbol.

[0043] Figure 2is an example illustration 200 of a subframe according to a possible embodiment, showing hybrid automatic repeat request-acknowledgement (HARQ-ACK) feedback in uplink subframe n+4 for a downlink rTTI in DL subframe n and a downlink sTTI in DL subframe n+2. HARQ feedback on the UL in response to DL data transmission on an sTTI that is less than the traditional 1ms TTI subframe operation can be enhanced to support reduced latency. The HARQ-ACK can represent an ACK / NACK / DTX response for a semi-persistent scheduling (SPS) release physical downlink control channel / enhanced physical downlink control channel (PDCCH / EPDCCH) or transport block associated with a serving cell. Other enhancements can also be used for channel state information (CSI) feedback.

[0044] In this first case, for reduced latency, the UE can be configured with a regular / legacy 1 ms TTI subframe, rTTI, and a shorter TTI, sTTI. Within the UL subframe, the UE may need to send HARQ-ACK feedback corresponding to the PDSCH transmission on both the rTTI and the sTTI. For reduced latency, a shorter TTI for transmitting at least the HARQ-ACK feedback for the sTTI may be preferred over a 1 ms legacy TTI for HARQ-ACK transmission for the rTTI. For example, the HARQ-ACK PUCCH sTTI may be a slot duration, such as 0.5 ms.

[0045] Figure 3 is an example illustration 300 of HARQ-ACK feedback in uplink subframe n+4 for downlink sTTI-1 in DL subframe n+2 and sTTI-2 in DL subframe n+2 according to a possible embodiment. In this second case, the UE may be configured with only sTTIs, where the downlink sTTI is shorter than the uplink TTI PUCCH used for HARQ-ACK transmission, such as 1 / 4 slot. In this case, the UE is able to send HARQ-ACK feedback corresponding to multiple sTTIs within a single uplink PUCCH TTI. The uplink PUCCH sTTI may be shorter than the traditional TTI size of a 1ms subframe, for example, the PUCCH sTTI may be a slot duration.

[0046] Figure 4 is an example illustration of a subframe 400 according to a possible embodiment, showing an example of PUCCH resource mapping for the first case with rTTI and sTTI. Figure 5is an example illustration of a subframe 500 according to a possible embodiment, which shows an example of PUCCH resource mapping for the second case with sTTI-1 and sTTI-2. For a combination of the above two cases, a mechanism for transmitting HARQ-ACK feedback for multiple TTIs with one uplink PUCCH TTI can be used.

[0047] For example, if rTTI is configured, the UE can determine the PUCCH resources (n-rTTI) corresponding to the PDSCH transmission or downlink SPS release associated with the traditional 1ms subframe, rTTI. The UE can determine the PUCCH resources (nsTTI) corresponding to the PDSCH transmission or downlink SPS release associated with the shorter TTI, sTTI. The determination of n-sTTI PUCCH resources can be implicit, such as based on a DL assignment message for PDSCH, such as the location and / or type of DCI, and / or the type of downlink control channel and / or a resource indicator in the DCI. The determination of n-sTTI PUCCH resources can also be explicitly configured through higher layer configuration. In an alternative, the transmit power control (TPC) field in the DCI can be used to convey a resource indicator indicating the PUCCH resources. The TPC field in the DCI or one of the TPC bits or states of other fields may also be used to indicate the presence of another TTI HARQ-ACK feedback, such as a TTI assignment indicator or counter, in the same uplink subframe / time slot that includes the sTTI HARQ-ACK feedback.

[0048] The mapping of n-sTTI PUCCH resources to physical resource blocks can be similar to n-rTTI, which is mapped to each of the two time slots in the uplink subframe. This may require the eNB to configure additional PUCCH resources, such as different PUCCH resource offsets and / or different PUCCH resource blocks, corresponding to multiple sTTIs that should carry HARQ-ACK feedback in the subframe, and thereby increase the uplink overhead. The use of dual-slot spanning n-sTTI PUCCH resource mapping can also increase the latency of sTTI transmissions. Alternatively, in order to reduce uplink overhead and latency, a shorter transmission duration can be used for n-sTTI, such as a one-slot PUCCH duration, where a PDSCH transmission received on an sTTI within the first time slot of a downlink subframe (n) can have corresponding PUCCH resources only in the first time slot of an uplink subframe (n+k), where HARQ-ACK feedback delay based on UE processing time, preparation of the HARQ-ACK uplink and / or uplink timing advance can be possible. A PDSCH transmission received on an sTTI in the second slot of a downlink subframe can have corresponding PUCCH resources only in the second slot of an uplink subframe. The downlink sTTI can be a slot duration or a portion of a slot duration. If the UE receives PDSCH transmissions only on rTTI or sTTI, HARQ-ACK can be sent on the corresponding PUCCH resources n-rTTI or n-sTTI, respectively.

[0049] Different options can be used for HARQ-ACK feedback when the UE may be required to send HARQ-ACK in the same uplink subframe corresponding to PDSCH transmissions on multiple TTIs, such as rTTI and sTTI, a first sTTI (sTTI-1) and a second sTTI (sTTI-2), and HARQ-ACK feedback for multiple TTIs overlaps with the subframe. The following description can be for the first case of rTTI and sTTI HARQ-ACK feedback, but can be extended for other cases, such as the second case with sTTI-1 and sTTI-2.

[0050] The first option can be to use multiple PUCCH resource transmission, where HARQ ACK corresponding to rTTI is sent on n-rTTI PUCCH resources, and HARQ ACK corresponding to sTTI is sent on n-sTTI PUCCH resources. Due to multiple PUCCH resource transmission, the cubic metric (CM) of the waveform can be increased, resulting in the use of larger power amplifier (PA) back-off and corresponding smaller uplink control channel coverage compared to traditional single PUCCH resource transmission.

[0051] A second option could be to use a larger payload PUCCH, where the HARQ-ACK bits corresponding to rTTI and sTTI are concatenated, encoded and sent on nrTTI PUCCH resources. In an alternative scheme, HARQ-ACK for both rTTI and sTTI can be sent only in a time slot with both n-rTTI and n-sTTI PUCCH resources, and in another time slot, HARQ-ACK can be sent only for rTTI on n-rTTI PUCCH resources. Spatial bundling, such as an "AND" operation between HARQ-ACK bits in the case of multiple transport block reception, can be used to reduce the payload size for sTTI and / or rTTI.

[0052] A third option could be to use PUCCH resource / channel selection, where in a time slot with overlapping PUCCH resources, such as n-sTTI PUCCH resources, 1 bit associated with HARQ-ACK, with or without spatial bundling of HARQ-ACK, can be encoded via selection between n-rTTI PUCCH resources and n-sTTI PUCCH resources. In another time slot, n-rTTI PUCCH resources can be used to send HARQACK corresponding to rTTI. In the case where a HARQ-ACK response corresponding to another sTTI may need to be sent on another time slot, PUCCH resource selection can also be used on another time slot. For the case of HARQ-ACK feedback for two TTIs (xTTI, yTTI) on the serving cell, the PUCCH resource selection is described in the following table.

[0053] In a third option, a UE configured with a transmission mode that supports up to two transport blocks on a TTI type (rTTI or sTTI) can respond to a PDSCH transmission with a single transport block or a PDCCH / EPDCCH indicating a downlink SPS release associated with the TTI type using the same HARQ-ACK response for two transport blocks. The transmission modes for rTTI and sTTI may be different. In the case of a transmission mode such as multiple-input multiple-output (MIMO) that supports up to two transport blocks on two TTIs, the HARQ-ACK feedback corresponding to one of the two TTIs can be bundled spatially, such as for the case of A=3-1 in the table below. xTTI can be a value from two TTI sets {rTTI, sTTI} or {sTTI-1, sTTI-2}. yTTI can be other TTIs. In one example, xTTI=rTTI, yTTI=sTTI, and can be fixed in the specification.

[0054] In an alternative approach, the values ​​of xTTI and yTTI can be based on the TTI assignment indicator and possibly on the mapped sTTI PUCCH resource slot index. For two TTIs {rTTI, sTTI}, if the TTI assignment indicator is "set" and the UE has missed the TTI assignment message corresponding to the rTTI, xTTI=sTTI and yTTI=rTTI can be used. Assuming that rTTI is not assigned, the UE can send HARQ-ACK on the sTTI PUCCH resources (n-sTTI). Since there is no transmission on the rTTI PUCCH resources in another time slot, the eNB can detect the missed rTTI assignment. The eNB can use the decision about the missed assignment to interpret the bits on the sTTI PUCCH resources, resulting in some potential delays if the sTTI PUCCH resources are in the first time slot of the uplink subframe. The options could be to use xTTI=sTTI and if sTTI PUCCH resources are in the second time slot then yTTI=rTTI and send HARQ-ACK assuming rTTI is not assigned, if sTTIPUCCH resources are in the first time slot then use xTTI=rTTI and yTTI=sTTI and send HARQ-ACK according to the following table, where transmission on n-sTTI PUCCH resources is not used to indicate NACK for yTTI and discontinuous transmission (DTX) for xTTI.

[0055] For two TTIs {sTTI-1, sTTI-2}, if the TTI assignment indicator is "set" and the UE has missed the TTI assignment message corresponding to sTTI-1, xTTI=sTTI-1 and yTTI=sTTI-2 can be used and HARQ-ACK can be sent according to the following table, where the transmission on the n-sTTI-1 PUCCH resource cannot be used to indicate NACK for yTTI and DTX for xTTI. If the TTI assignment indicator is set and the UE has received an rTTI assignment message, xTTI=rTTI and yTTI=sTTI. HARQ-ACK can be sent according to the following table, where sTTI HARQ-ACK feedback is used for resource selection.

[0056] Table 1 shows the mapping options of transport blocks (TBs) and TTIs to HARQ ACK (j) for PUCCH format 1b HARQ-ACK channel selection within a slot according to possible embodiments.

[0057] Table 1

[0058]

[0059] Table 2 shows the transmission of Format 1b ACK / NACK channel selection for A=2 according to a possible embodiment.For Tables 2 and 3, "A" represents the number of HARQ-ACK responses after spatial bundling for 3-1.

[0060] Table 2

[0061]

[0062] Table 3 shows the transmission of Format 1b ACK / NACK channel selection for A=3,3-1 according to a possible embodiment.

[0063] Table 3

[0064]

[0065] In an alternative, for a transmission mode such as MIMO that supports up to two transport blocks, two PUCCH resources (n-xTTI-1, n-xTTI-2) can be determined. Resource n-xTTI-1 similar to the above can be determined, and resource n-xTTI-2 can be determined as n-xTTI-2=n-xTTI-1+1. Resource selection tables for A=3 and A=4 are given below. These tables are similar to the 2-cell carrier aggregation tables in LTE. For A=3, xTTI is a TTI with a transmission mode such as MIMO that supports up to two transport blocks. If no other TTIs are assigned or detected, the PUCCH resources corresponding to the TTI, such as the first PUCCH resource in the case where the TTI supports two TBs, can be used for HARQ-ACK feedback for the TTI, such as providing a fallback. If HARQ ACK feedback of ACK is to be indicated for a TTI that supports 1TB, the second PUCCH resource for the TTI that supports two TBs can be used. The TTI assignment indicator may not be needed since the additional PUCCH resources for two TB TTIs can be used to provide a fallback in case of a missed assignment message.

[0066] Table 4 shows the transmission of Format 1b ACK / NACK channel selection for A=3, for two PUCCH resources for two transport block TTIs according to a possible embodiment.For Tables 4 and 5, "A" represents the number of PUCCH resources.

[0067] Table 4

[0068]

[0069] Table 5 shows the transmission of format 1b ACK / NACK channel selection for A=4, for two PUCCH resources for two transport block TTIs according to a possible embodiment.

[0070] Table 5

[0071]

[0072] To extend to carrier aggregation (CA), larger payload PUCCH or PUCCH resource selection with spatial bundling and / or time domain bundling or compression can be used, such as similar to current time division duplex (TDD) CA.

[0073] Figure 6 600 is an uplink example subframe showing simultaneous PUSCH on sTTI and rTTI with common RS symbol positions and separate DFT precoding according to a possible embodiment. For UL shared channels for sTTI operation, the uplink rTTI and sTTI within a subframe can have common RS symbol positions. In the case of simultaneous transmission on an uplink rTTI and an uplink sTTI within a subframe, such as an sTTI that overlaps with the rTTI in time and includes a subset of SC-FDMA symbols, separate DFT precoding can be applied to the PUSCH corresponding to the sTTI and rTTI to achieve faster decoding, such as separate receiver processing blocks for rTTI and sTTI with different power levels, different modulation and coding schemes (MCS), and other differences.

[0074] Figure 7 7 is an example subframe 700 according to a possible embodiment, which shows an uplink of simultaneous PUSCH on sTTI and rTTI with common RS symbol positions and separate DFT precoding. In the case where the sTTI PUSCH REs overlap with rTTI PUSCH REs within the subframe, the PUSCH corresponding to the sTTI can be sent, such as where the sTTI preempts the rTTI on the overlapping SC-FDMA symbols and the rTTI SCFDMA symbols are punctured. The PUSCH corresponding to the rTTI can be sent on the remaining SC-FDMA symbols.

[0075] In current LTE systems, the maximum transmit power is based on the path loss (PL), a set of higher layer configured parameters such as P0 and α, the PRB pairs allocated to the UE (M_PUSCH_RB), the subframe applicable for transmission, and the configured maximum transmit power of the serving cell (such as P for serving cell c and subframe n). cmax_c(n)), and power control adjustments received via DL physical layer control signaling (PDCCH / EPDCCH) to calculate the UE transmit power for a given serving cell. For UE transmissions with shorter TTIs, an advanced approach similar to the current LTE system can be used. However, for sTTI operation, the overall system performance can be improved by configuring a separate set of higher layer power control parameters, such as P0 and α, for conventional TTI operation and sTTI operation for each physical channel for a given serving cell. For example, separate higher layer parameters can be used for rTTI-based PUSCH and sTTI-based sPUSCH.

[0076] If a UE is scheduled to perform sTTI transmission and rTTI transmission in the same subframe and the same serving cell, the UE shall ensure that the sTTI transmission is performed in such a way that its total transmission power does not exceed P of the subframe and the serving cell. cmax_c For a UE configured with multiple serving cells, such as a UE supporting carrier aggregation, if the UE has a normal TTI transmission on one serving cell and an sTTI transmission on another serving cell, the UE can ensure that the total transmission power through the two serving cells does not exceed the applicable subframe power (P cmax ) configured maximum transmit power. This can be used to ensure that the UE's transmissions comply with any rules defined for the frequency band in which the UE is operating, to minimize out-of-band emissions and adjacent channel leakage ratio (ACLR), and to minimize frequency band interference by adhering to power control limits.

[0077] If the UE has to perform sTTI based transmission in at least SC-FDMA symbol x in subframe n with transmission power Pstti, and the UE is also scheduled with conventional TTI transmission in subframe n with transmission power Prtti, the UE can use one or more of the following methods to determine the transmission and power level of subframe n.

[0078] According to one method of determining transmissions and power levels for subframe n, the UE can prioritize transmissions according to one or more priority rules defined below and send only the highest priority transmission and discard all other transmissions in that subframe.

[0079] According to another method of determining the transmission and power level for subframe n, the UE can send both sTTI and regular transmissions. If the total transmission power of both sTTI transmissions and regular transmissions, such as during all SC-FDMA symbol durations in a subframe, is less than P cmax_c(n), this can be done without any power scaling. If the total transmission power of both sTTI transmission and regular transmission during any SC-FDMA symbol duration in a subframe would exceed P cmax_c(n) , the UE is able to scale the sTTI transmission power or the regular transmission power according to one or more priority rules so that, after scaling, the total transmission power of both sTTI transmission and regular transmission will not exceed P during all SC-FDMA symbol durations in the subframe cmax_c(n) .

[0080] One priority rule can be that a transmission of a particular TTI length, such as a shorter TTI, can be prioritized over a transmission of another TTI length, such as a longer TTI. According to another example, a transmission with a longer TTI can be prioritized over a transmission with a shorter TTI. This can be predefined or indicated to the UE via higher layer signaling or by other signaling as described below.

[0081] Another priority rule can be to be able to indicate prioritized transmissions to the UE via signaling. For example, if a UE is scheduled to transmit in subframe n using a regular TTI, such as via a first UL grant, and is also scheduled to transmit in an sTTI in subframe n, such as via a second UL grant, then a bit such as a priority flag field or a code point in the first grant can indicate whether the UE should prioritize the transmission scheduled by the first grant. Similarly, a bit such as a priority flag field or a code point in the second grant can indicate whether the UE should prioritize the transmission scheduled by the second grant.

[0082] Another priority rule can be a prioritization based on a combination of payload type, sTTI length, and physical channel type. For example, considering the following transmissions, the prioritization can be 1>2>3>4>5>6. Alternatively, the prioritization can be 2>1>3>4>5>6. These numbers can indicate 1) sTTI transmissions with HARQ-ACK; 2) sTTI transmissions in response to a UL grant with a priority flag field set to 1; 3) rTTI transmissions with HARQ-ACK; 4) sTTI transmissions without HARQ-ACK; 5) rTTI transmissions without HARQ-ACK; and 6) SRS transmissions.

[0083] Due to the overlap with the sTTI transmission in symbol x of subframe n, the UE may need to scale the transmit power of conventional transmission in subframe n. The UE is able to scale the transmit power of conventional transmission in all SC-FDMA symbols of subframe n where conventional transmission is performed. For example, the UE is able to use the same transmit power for all SC-FDMA symbols of subframe n where conventional transmission is performed. This can make it easier for the network to decode UE transmissions. Alternatively, the UE is able to scale the transmit power of conventional transmission in all SC-FDMA symbols of time slots of subframe n where conventional transmission and sTTI transmission overlap in time. Alternatively, the UE is able to scale the transmit power of conventional transmission only in SC-FMA symbol x of subframe n. This can ensure that at least other symbols are sent with higher power and can improve robustness. However, the network should be able to take into account the power differences between various SC-FDMA symbols when decoding conventional transmissions.

[0084] If a UE is scheduled to send a regular TTI transmission in a subframe and to send multiple sTTI transmissions in the same subframe, the UE can scale the regular TTI transmission power so that the total transmission power taking into account the scaled regular TTI transmission power and the sTTI transmission with the maximum power among the sTTI transmissions scheduled for the subframe does not exceed the configured maximum transmission power for the subframe. In some cases, such as when UL carrier aggregation is used, regular TTI transmissions and sTTI transmissions can be scheduled on different uplink component carriers or serving cells. When regular TTI transmissions and sTTI transmissions are performed on the same serving cell, it can generally be assumed that they use the same timing advance (TA) value. The TA value can be used to determine the start of each UL subframe with respect to the corresponding DL subframe.

[0085] To help the network set up or adjust UL transmission power, the UE can send one or more types of power headroom reports (PHRs). For example, at a high level, the UE can send a first type of PHR applicable to regular TTI transmissions and a second type of PHR applicable to shorter TTI transmissions.

[0086] In another example, the UE can send a first type of PHR for a subframe, where assuming there is only one type of TTI transmission in the subframe, the UE can calculate the configured maximum transmit power used for PHR calculation for the subframe, such as P cmax_c, even if there are actually transmissions of both types of TTI transmissions in the subframe. This can be a PHR where the configured maximum transmit power is calculated assuming that only regular TTI transmissions are present in the subframe, even if both regular TTI and sTTI transmissions are actually scheduled for the subframe. The UE can also send a second type of PHR for a subframe, where the PHR is calculated assuming that both regular TTI transmissions and sTTI transmissions are present in the subframe, even if only one type of TTI transmission is actually sent in the subframe. For example, the UE can report a PHR where the PHR is calculated assuming that the UE has both sTTI transmissions and regular TTI transmissions in the subframe. If the UE is actually scheduled to send only regular TTI transmissions in the subframe, the power adjustment for the assumed sTTI transmission used for the PHR calculation can be calculated assuming a fixed resource allocation, such as 1RB, and a TPC command value, such as 0dB.

[0087] Figure 8 is an example diagram 800 of device-to-device (D2D), such as sidelink, operation according to possible embodiments. D2D can be a broadcast type communication where the transmitting device may not be aware of the configuration of the receiving device, such as by the TTI length used by the receiving UE for UL / DL communication with the base station. Therefore, a common TTI length for D2D operation can be used for all UEs. For example, to maintain backward compatibility, a 1 ms TTI can be used for D2D operations, such as for discovery and communication, while each UE can support a shortened TTI for UL or DL ​​communication with the eNB. Assuming the use of a common TTI length for D2D operation, such as 1 ms, coexistence with cellular operations can be ensured.

[0088] Fig. 9 is an example illustration of a 1ms D2D subframe 900 with 2 symbols UL data in symbols 9-10 according to a possible embodiment. From a single user perspective, cellular operation can be prioritized; that is, if the UE's UL communication overlaps with its sidelink transmission, the sidelink transmission can be abandoned. If the UE is sending a D2D signal using a 1ms-TTI and it is scheduled to send UL data in symbols 9 and 10, the UE may not send a D2D signal at symbols 9 and 10. However, the UE does not need to abandon the entire D2D subframe, which is the case with the current specification. Different methods can be used to handle the case where the sidelink operation coincides with sTTI operation in the UL in a subframe.

[0089] According to one possible approach, when a D2D subframe and sTTI data overlap, the entire D2D subframe can be discarded and the UE can only send data in the sTTI. This approach can be compatible with existing specifications, but depending on the arrival rate of low-latency data and HARQ and TCP ACK delays, multiple subframes may be affected (such as causing abandonment) while there are only a small number of subframes that conflict with sTTI data. For example, for a round-trip time (RTT) HARQ delay of 8 TTIs and a TTI length of 2 symbols, all consecutive UL subframes can contain sTTI data, each in only 2 symbols out of 14 symbols. In the case of a D2D subframe configuration such as indicated for consecutive subframes, multiple D2D subframes can be abandoned.

[0090] According to another possible approach, a D2D receiver such as a receiving UE can be informed which symbols can be punctured in a D2D subframe. For example, within or at the beginning of a D2D subframe, a transmitting UE can inform all D2D receivers which symbol indices will be punctured, such as for non-D2D operation. The information can be conveyed explicitly or implicitly, such as via a scrambling sequence. Due to the different TA assumptions for UL and D2D, the receiving and transmitting UEs can also abandon previous symbols before signaling the UL transmission position. The transmitting UE can also indicate such puncturing in a scheduling assignment sent to the D2D receiver. If a good portion of the D2D subframe is to be used through sTTI UL operation, the UE can abandon the D2D subframe. The abandonment threshold, such as exceeding one time slot in time, can be signaled by the serving cell or fixed in the specification. Unlike existing specifications where D2D reception is not possible in a subframe in which the receiving D2D UE has UL data to send, in the case of sTTI operation, when the D2D receiving UE has an sTTI for UL transmission, only those symbols affected by the UL transmission cannot be used for D2D reception.

[0091] Fig.10 is an example flow chart 1000 illustrating operation of a device, such as device 110, according to a possible embodiment. At 1010, a prioritization indicator can be received indicating which of a first uplink transmission and a second uplink transmission takes precedence over the other.

[0092] At 1020, the priorities of the first uplink transmission and the second uplink transmission may be arranged. The priorities may be arranged based on the prioritization indicator if such an indicator is received. Alternatively, the priorities may be arranged using a priority rule based on a combination of payload type, sTTI length, and physical channel type. The priorities of the first uplink transmission and the second uplink transmission may also be arranged based on the type of transmission. The priorities of the first uplink transmission and the second uplink transmission may be additionally arranged in the case where the transmission with a smaller TTI length has a higher priority.

[0093] At 1030, a first transmission power for a first uplink transmission may be determined at a device based on a first set of power control parameters configured by a higher layer associated with a first TTI length. The higher layer may be higher than the physical layer. The first uplink transmission may span the first TTI length. The first TTI length may include a first number of SC-FDMA symbols. The first uplink transmission may carry data, HARQ-ACK, and / or other transmissions. The same transmission power may be determined for all SC-FDMA symbols of the first uplink transmission. The SC-FDMA symbols in the first number of SC-FDMA symbols of the first uplink transmission may be based on a DFT extension according to the number of frequency resources used for the first uplink transmission. The first transmission power may be determined by determining a scaling factor value and using the scaling factor value when determining the first transmission power.

[0094] At 1040, a second transmission power for a second uplink transmission may be determined based on a second set of power control parameters configured by a higher layer associated with a second TTI length. The second uplink transmission may span a second TTI length. The second TTI length may include a second number of SC-FDMA symbols and the second number may be different from the first number. The SC-FDMA symbols in the second number of SC-FDMA symbols for the second uplink transmission may be based on a DFT extension according to the number of frequency resources used for the second uplink transmission. The second uplink transmission may carry data, HARQ-ACK, and / or other transmissions.

[0095] The first uplink transmission and the second uplink transmission may be performed using the same timing advance (TA) value. The overlapping SC-FDMA symbols of the first uplink transmission and the second uplink transmission may be based on a first DFT spreading according to the number of frequency resources used for the first uplink transmission (e.g., a first DFT spreading on a first number of subcarriers used for the first uplink transmission) and based on a second DFT spreading according to the number of frequency resources used for the second uplink transmission (e.g., a second separate DFT spreading on a second number of subcarriers used for the second uplink transmission). The first uplink transmission and the second uplink transmission may be performed on the same uplink carrier.

[0096] According to different embodiments, the first transmission power of the first uplink transmission may be determined so that the combined transmission power of the first uplink transmission and the second uplink transmission during any SC-FDMA symbol in the subframe does not exceed the configured maximum transmit power value. The first transmission power of the first uplink transmission may also be determined based on the priority of the scheduled first uplink transmission and the second uplink transmission. The same transmission power may be determined for the overlapping SC-FDMA symbols of the first uplink transmission that appear in the subframe where the first uplink transmission and the second uplink transmission overlap in time. Different transmission power levels may be determined for the symbols where the first transmission and the second transmission overlap each other in time and for the symbols where the first transmission and the second transmission do not overlap each other in time. The first transmission power of the first uplink transmission may also be determined based on a priority rule according to which the first uplink transmission has a lower priority than the second uplink transmission. In addition, the same transmission power may be determined for all SC-FDMA symbols of the first uplink transmission that appear in the same time slot of the subframe where the first uplink transmission and the second uplink transmission overlap in time.

[0097] At 1050, a first uplink transmission may be sent in the subframe using a first transmission power. At 1060, at least a second uplink transmission may be sent in the subframe using a second transmission power. The first uplink transmission and the second uplink transmission may overlap in time by at least one SC-FDMA symbol duration.

[0098] It should be understood that, although specific steps are shown in the accompanying drawings, various additional or different steps can be performed depending on the embodiment, and one or more specific steps can be rearranged, repeated, or completely eliminated depending on the embodiment. Moreover, some steps can be repeated simultaneously on a continuous or consecutive basis while other steps are performed. In addition, different steps can be performed by different elements or in a single element of the disclosed embodiments.

[0099] Fig.11 1 is an example block diagram of an apparatus 1100, such as a wireless communication device 110, according to possible embodiments. The apparatus 1100 can include a housing 1110, a controller 1120 within the housing 1110, audio input and output circuitry 1130 coupled to the controller 1120, a display 1140 coupled to the controller 1120, a transceiver 1150 coupled to the controller 1120, an antenna 1155 coupled to the transceiver 1150, a user interface 1160 coupled to the controller 1120, a memory 1170 coupled to the controller 1120, and a network interface 1180 coupled to the controller 1120. The apparatus 1100 can perform the methods described in all embodiments.

[0100] Display 1140 can be a viewfinder, a liquid crystal display (LCD), a light emitting diode (LED) display, a plasma display, a projection display, a touch screen, or any other device that displays information. Transceiver 1150 can include a transmitter and / or a receiver. Audio input and output circuit 1130 can include a microphone, a speaker, a transducer, or any other audio input and output circuit. User interface 1160 can include a keypad, a keyboard, a button, a touch pad, a joystick, a touch screen display, other additional displays, or any other device for providing an interface between a user and an electronic device. Network interface 1180 can be a universal serial bus (USB) port, an Ethernet port, an infrared transmitter / receiver, an IEEE 1394 port, a WLAN transceiver, or any other interface that can connect the device to a network, a device, or a computer and can send and receive data communication signals. Memory 1170 can include random access memory, read-only memory, optical memory, flash memory, removable memory, a hard drive, a cache, or any other memory that can be coupled to the device.

[0101] Device 1100 or controller 1120 may implement any operating system, such as Microsoft or Android TM or any other operating system. For example, the device operating software can be written in any programming language, such as C, C++, Java or Visual Basic. The device software can also be written in an application framework, such as frame, The disclosed embodiments may also be implemented on a general or special purpose computer, a programmed microprocessor or microprocessors, peripheral integrated circuit components, application specific integrated circuits or other integrated circuits, hardware / electronic logic circuits, such as discrete component circuits, programmable logic devices, such as programmable logic arrays, field programmable gate arrays, etc. In general, the controller 1120 may be any controller or processor device capable of operating the apparatus and implementing the disclosed embodiments.

[0102] In operation according to a possible embodiment, the controller 1120 can determine a first resource for sending a scheduling request indication in a subframe. The first resource can be associated with uplink data transmission using a first TTI length. The first TTI length can include a first number of SC-FDMA symbols. The controller 1120 can determine a second resource used to send a scheduling request indication in a subframe. The second resource can be associated with uplink data transmission using a second TTI length. The second TTI length can include a second number of SC-FDMA symbols. The second number of SC-FDMA symbols can be less than the first number of SC-FDMA symbols.

[0103] The controller 1120 can select a scheduling request indication resource from one of the first resource and the second resource. When the device 1100 has data to be sent using a TTI with a second number of SC-FDMA symbols, the controller 1120 can select the second resource as the scheduling request indication resource. When the device 1100 has data to be sent with a specific characteristic, the controller 1120 can also select the second resource as the scheduling request indication resource, and when the device has data to be sent without a specific characteristic, the controller 1120 can select the first resource as the scheduling request indication resource. The transceiver 1150 can send a scheduling request indication in the selected scheduling request indication resource in the subframe.

[0104] According to a possible implementation, the first resource can be a first PUCCH resource, and the second resource can be a second PUCCH resource.When the device has to send a HARQ-ACK indication in a subframe, the transceiver 1150 can send the HARQ-ACK indication in the selected scheduling request indication resource.

[0105] According to another possible implementation, the first resource can be a PUCCH resource and the second resource can be an SRS resource. When the apparatus 1100 also has to send a preconfigured SRS transmission in a subframe and when the selected scheduling request indicates that the resource is the second resource, the transceiver 1150 can send a scheduling request instead of a preconfigured SRS transmission in the subframe.

[0106] According to another possible implementation, the first resource can be a first PRACH resource, and the second resource can be a second PRACH resource. When the apparatus 1100 has data to be sent using a second TTI length, the controller 1120 can select the second PRACH resource as a scheduling request indication. The transceiver 1150 can use the second PRACH resource in the subframe to send a RACH preamble.

[0107] According to another possible implementation, the first resource can be a PUCCH resource, and the second resource can be a DMRS resource.The transceiver 1150 can transmit the DMRS using at least one selected from a DMRS cyclic shift value associated with the scheduling request transmission and an orthogonal sequence associated with the scheduling request transmission.

[0108] In operation according to another possible embodiment, when the device 1100 is configured for UL transmission using a first TTI length, the controller 1120 can use a first buffer status report (BSR) configuration, and when the device 1100 is configured for UL transmission using at least a second TTI length that is shorter than the first TTI length, a second BSR configuration can be used. The controller 1120 can determine whether the device 1100 has data to be sent using a specific characteristic. The data to be sent using the specific characteristic can be data that requires TTI resources using a second TTI length. The specific characteristic can be a specific QoS class identifier, a specific resource type, a specific priority level, a specific packet delay budget, a specific packet error loss rate, a specific delay requirement, a specific logical channel group identifier, and / or any other characteristic that may affect the BSR configuration. The specific characteristic can be associated with a reduced latency data transmission, which has a reduced latency relative to other data transmission latency.

[0109] When the apparatus 1100 has data to be transmitted with a specific characteristic, the transceiver 1150 can transmit the BSR using the second BSR configuration. When the apparatus 1100 has data to be transmitted without a specific characteristic, the transceiver 1150 can transmit the BSR using the first BSR configuration.

[0110] In operation according to another possible embodiment, the transceiver 1150 can receive a first downlink transmission in a first downlink TTI of a first duration in a first downlink subframe. The first downlink transmission can be a PDSCH transmission. The first downlink transmission can also be a control channel transmission indicating an SPS release. The transceiver 1150 can receive a second downlink transmission in a second downlink TTI of a second duration in a second downlink subframe. The first downlink TTI and the second downlink TTI may not overlap. The second downlink transmission can be a PDSCH transmission.

[0111] The controller 1120 can determine a first HARQ-ACK feedback and a first HARQ-ACK PUCCH resource in response to receiving a first downlink transmission in a first downlink TTI.The first HARQ-ACK PUCCH resource can be mapped to REs in a first uplink TTI of a third duration in a first uplink subframe.

[0112] The controller 1120 can determine a second HARQ-ACK feedback and a second HARQ-ACK PUCCH resource in response to receiving a second downlink transmission in a second downlink TTI. The second HARQ-ACK PUCCH resource can be mapped to an RE in a second uplink TTI of a fourth duration in a first uplink subframe. The first UL TTI can include a time portion overlapping with the second UL TTI. According to a possible implementation, the second downlink transmission can include two transport blocks, and the second HARQ-ACK feedback can be a spatial HARQ-ACK bundling response by a logical AND operation of corresponding individual HARQ-ACKs for the two transport blocks.

[0113] According to another possible implementation, the first downlink subframe can be different from the second downlink subframe, the second duration can be less than the first duration, and the fourth duration can be less than the third duration. According to another possible implementation, the first downlink subframe can be the same as the second downlink subframe, the second duration can be equal to the first duration, and the fourth duration can be equal to the third duration. According to another possible implementation, the second duration can be less than the fourth duration. According to another possible implementation, the first downlink TTI can include a first number of OFDM symbols, the second downlink TTI can include a second number of OFDM symbols, the first uplink TTI can include a first number of SC-FDMA symbols, and the second downlink TTI can include a second number of OFDM symbols.

[0114] The controller 1120 is capable of selecting between the first HARQ-ACK PUCCH resource and the second HARQ-ACK PUCCH resource based at least on the determined second HARQ-ACK feedback. The transceiver 1150 is capable of sending a signal in response to the first HARQ-ACK feedback and the second HARQ-ACK feedback determined on the selected HARQ-ACK PUCCH resource on the overlapping portion of the first uplink TTI and the second uplink TTI in the first uplink subframe. According to one possible embodiment, the transmitted signal includes a first signal, and the transceiver is capable of sending a second signal in response to the first HARQ-ACK feedback determined on the first HARQ-ACK PUCCH resource on the time portion of the first UL TTI that does not overlap with the second UL TTI.

[0115] In operation according to another possible embodiment, the controller 1120 can determine a first transmission power for a first uplink transmission based on a first set of power control parameters configured by a higher layer associated with a first TTI length. The higher layer can be higher than the physical layer. The first uplink transmission can span a first TTI length. The first TTI length can include a first number of SC-FDMA symbols. The first uplink transmission can carry data, HARQ-ACK, and / or any other transmission.

[0116] The controller 1120 can determine a second transmission power for the second uplink transmission based on a second set of power control parameters configured by a higher layer associated with the second TTI length. The second uplink transmission can span a second TTI length. The second TTI length can include a second number of SC-FDMA symbols. The second number can be different from the first number. The second uplink transmission can carry data, HARQ-ACK, and / or any other transmission.

[0117] According to a possible implementation, the controller 1120 can determine the first transmission power of the first uplink transmission so that the combined transmission power of the first uplink transmission and the second uplink transmission during any SC-FDMA symbol in the subframe does not exceed the configured maximum transmit power value. According to another possible implementation, the controller 1120 can determine the first transmission power of the first uplink transmission based on a priority rule, according to which the first uplink transmission has a lower priority than the second uplink transmission.

[0118] The transceiver 1150 can send a first uplink transmission in a subframe using a first transmission power. The transceiver 1150 can send at least a second uplink transmission in a subframe using a second transmission power. The first uplink transmission and the second uplink transmission overlap in time for at least one SC-FDMA symbol duration.

[0119] In operation according to another possible embodiment, the controller 1120 can calculate a first type of power headroom report (PHR) based on the presence of only transmissions of a first TTI length in a subframe. Even if there are transmissions of the first TTI length and transmissions of a second TTI length in the subframe, the controller 1120 can calculate the first type of PHR based on the presence of only transmissions of the first TTI length in the subframe. The controller 1120 can calculate the first type of PHR based on a first set of power control parameters configured by a higher layer associated with the first TTI length.

[0120] The controller 1120 can calculate the second type of PHR based on the presence of both the first TTI length and the second TTI length in the subframe. Even if there is only one of the first TTI length and the second TTI length in the subframe, the controller can calculate the second type of PHR based on the presence of the first TTI length and the second TTI length in the subframe. If there is no transmission of the second TTI length in the subframe, the controller 1120 can calculate the second type of PHR based on a fixed resource block allocation and a fixed TPC command value. The controller 1120 can calculate the second type of PHR based on a first set of power control parameters configured by a higher layer associated with the first TTI length and a second set of power control parameters configured by a higher layer associated with the second TTI length. The controller 1120 can calculate the second type of PHR based on a fixed resource block allocation and a fixed TPC command value for transmission of the second TTI length. The controller 1120 can calculate the second type of PHR based on a fixed resource block allocation and a fixed TPC command value for transmission of the second TTI length. The controller 1120 can calculate the second type of PHR based on a resource block allocation and a TPC command value for physical channel transmission of the second TTI length received in an uplink grant.

[0121] The controller 1120 can calculate the first type of PHR and / or the second type of PHR by calculating the PHR based on transmission of only the first type of physical channel in the subframe. The first type of physical channel can be a PUSCH. The controller 1120 can calculate the first type of PHR and / or the second type of PHR by calculating the PHR based on at least two types of physical channels in the subframe. The at least two types of the first type of physical channels can be PUSCH, and the at least two types of the second type of physical channels can be PUCCH.

[0122] The transceiver 1150 can send a first type of PHR and at least a second type of PHR. The transceiver 1150 can send at least a second type of PHR in a subframe using a physical channel transmission of a first TTI length, and the second TTI length can be shorter than the first TTI length. The transceiver 1150 can send a second type of PHR in a subframe using a physical channel transmission of a second TTI length, and the second TTI length can be shorter than the first TTI length.

[0123] In operation according to another possible embodiment, the controller 1120 can compare the number of SC-FDMA symbols used for UL transmission in a TTI with a threshold value of the SC-FDMA symbol. The transceiver 1150 can send an indication on a sidelink channel. When the number of SC-FDMA symbols occupied by the UL transmission is less than the threshold value, the indication can indicate the position of the SC-FDMA symbol used for the UL transmission. The indication can be sent in a scheduling allocation sent by a device on the sidelink channel. The scrambling sequence for the sidelink transmission can be used to indicate the position of the SC-FDMA used for the UL transmission. The sidelink channel can be a sidelink shared channel, a sidelink control channel, a sidelink discovery channel, and / or any other sidelink channel. When the number of SC-FDMA symbols occupied by the UL transmission is less than the threshold value, the transceiver 1150 can send both the sidelink transmission and the UL transmission in the TTI. When the number of SC-FDMA symbols occupied by the UL transmission is less than the threshold value, the controller 1120 can abandon the symbol associated with the sidelink transmission, wherein the symbol can be immediately before the UL transmission. The sidelink transmission and the UL transmission may not overlap in time. When the number of SC-FDMA symbols occupied by the UL signal is at least a threshold, the transceiver 1150 can send only UL transmission in a TTI. The transceiver 1150 can send only UL transmission by abandoning all sidelink transmissions scheduled during the TTI. The TTI can be a first TTI having a first TTI length, and the UL transmission can be sent using a second TTI having a TTI length less than the first TTI length, wherein the first TTI and the second TTI overlap in time.

[0124] The method of the present disclosure can be implemented on a programmed processor. However, the controller, flow chart and modules can also be implemented on a general or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit components, an integrated circuit, a hardware electronic or logic circuit such as a discrete component circuit, a programmable logic device, etc. In general, any device on which resides a finite state machine capable of implementing the flow charts shown in the accompanying drawings can be used to implement the processor functions of the present disclosure.

[0125] Although the present disclosure has been described with its specific embodiments, it is apparent that many substitutions, modifications and variations are apparent to those skilled in the art. For example, in other embodiments, the various components of the embodiments may be interchanged, added or replaced. Moreover, all elements of each of the accompanying drawings are not necessary for the operation of the disclosed embodiments. For example, by simply adopting the elements of the independent claims, a person of ordinary skill in the art of the disclosed embodiments is enabled to make and use the teachings of the present disclosure. Therefore, the embodiments of the present disclosure as described herein are intended to be illustrative rather than restrictive. Various changes may be made without departing from the spirit and scope of the present disclosure.

[0126] In this document, in the absence of any actual such relationship or order between such entities or actions, relational terms such as "first", "second", etc. can be used only to distinguish one entity or action from another entity or action. The phrases "at least one", "at least one selected from a group", or "at least one selected from" followed by a list are defined to mean one, some or all, but not necessarily all elements in the list. The terms "include", "comprise", "include", "include" or any other variation thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including the list of elements does not include only those elements, but may include other elements that are not explicitly listed or inherent in these processes, methods, articles or devices. In the absence of more constraints, the elements continued by "one", "one", etc. do not exclude the presence of additional identical elements in the process, method, article or device including the element. Moreover, the term "another" is defined as at least the second or more. The terms "include", "have", etc. as used herein are defined as "include". In addition, the background technology section is written as the inventor's own understanding of the context of some embodiments at the time of filing, and includes the inventor's own recognition of any problems with the prior art and / or problems encountered in the inventor's own work.

Claims

1. A method for scheduling uplink transmission with reduced latency, the method comprising: receiving, in a subframe, a first uplink transmission sent using a first transmission power; receiving, in the subframe, at least a second uplink transmission sent using a second transmission power, wherein the first uplink transmission and the second uplink transmission overlap in time by at least one symbol duration; wherein the first transmission power of the first uplink transmission is based on a first set of higher layer configured power control parameters associated with a first transmission time interval length, wherein the first uplink transmission spans the first transmission time interval length, and wherein the first transmission time interval length includes a first number of symbols; and A second transmission power for a second uplink transmission is based on a second set of higher layer configured power control parameters associated with a second transmission time interval length, wherein the second uplink transmission spans the second transmission time interval length, and wherein the second transmission time interval length includes a second number of symbols and the second number is different from the first number.

2. The method according to claim 1, in, The first uplink transmission carries at least one selected from data and a hybrid automatic repeat request response, and The second uplink transmission bears at least one selected from data and a hybrid automatic repeat request response.

3. The method according to claim 1, further comprising: sending an indication of a priority for each of the first uplink transmission and the second uplink transmission, wherein the first uplink transmission and the second uplink transmission are received based on a priority for each of the first uplink transmission and the second uplink transmission.

4. The method according to claim 3, wherein: symbols of the first number of symbols of the first uplink transmission are spread based on a discrete Fourier transform according to the number of frequency resources used for the first uplink transmission, and Symbols of the second number of symbols of the second uplink transmission are based on a discrete Fourier transform spreading according to a number of frequency resources used for the second uplink transmission.

5. The method according to claim 4, wherein: The overlapping symbols of the first uplink transmission and the second uplink transmission are based on a first discrete Fourier transform extension of the frequency resources used for the first uplink transmission according to the number of the frequency resources used for the first uplink transmission, and based on a second discrete Fourier transform extension of the frequency resources used for the second uplink transmission according to the number of the frequency resources used for the second uplink transmission.

6. The method according to claim 1, wherein: The first uplink transmission and the second uplink transmission are associated with a same timing advance value.

7. The method according to claim 1, wherein: The first number of symbols comprises a first number of single carrier frequency division multiple access symbols, and wherein the second number of symbols comprises a second number of single carrier frequency division multiple access symbols.

8. A base station for scheduling uplink transmission with reduced latency, comprising: Memory; as well as a processor coupled to the memory, the processor being configured to cause the base station to: receiving, in a subframe, a first uplink transmission associated with a first transmission power; receiving at least a second uplink transmission associated with a second transmission power in the subframe, wherein the first uplink transmission and the second uplink transmission overlap in time by at least one symbol duration wherein the first transmission power associated with the first uplink transmission is based on a first set of power control parameters of a higher layer configuration associated with a first transmission time interval length, wherein the first uplink transmission spans the first transmission time interval length, and wherein the first transmission time interval length includes a first number of symbols, and wherein the second transmission power associated with the second uplink transmission is based on a second set of power control parameters of a higher layer configuration associated with a second transmission time interval length, wherein the second uplink transmission spans the second transmission time interval length, and wherein the second transmission time interval length includes a second number of symbols and the second number is different from the first number.

9. The base station according to claim 8, in, The first uplink transmission carries at least one selected from data and a hybrid automatic repeat request response, and The second uplink transmission bears at least one selected from data and a hybrid automatic repeat request response.

10. The base station according to claim 8, wherein the processor is further configured to cause the base station to: sending an indication of a priority for each of the first uplink transmission and the second uplink transmission, in, The first uplink transmission and the second uplink transmission are received based on a priority for each of the first uplink transmission and the second uplink transmission.

11. The base station according to claim 8, wherein: symbols of the first number of symbols of the first uplink transmission are spread based on a discrete Fourier transform according to the number of frequency resources used for the first uplink transmission, and Symbols of the second number of symbols of the second uplink transmission are based on a discrete Fourier transform spreading according to a number of frequency resources used for the second uplink transmission.

12. The base station according to claim 11, wherein: The overlapping symbols of the first uplink transmission and the second uplink transmission are based on a first discrete Fourier transform extension of the frequency resources used for the first uplink transmission according to the number of the frequency resources used for the first uplink transmission, and based on a second discrete Fourier transform extension of the frequency resources used for the second uplink transmission according to the number of the frequency resources used for the second uplink transmission.

13. The base station according to claim 8, wherein: The first uplink transmission and the second uplink transmission are associated with a same timing advance value.

14. The base station according to claim 8, wherein: The first number of symbols comprises a first number of single carrier frequency division multiple access symbols, and wherein the second number of symbols comprises a second number of single carrier frequency division multiple access symbols.

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