Source: https://patents.google.com/patent/KR102001991B1/en
Timestamp: 2020-05-28 05:25:25
Document Index: 620740077

Matched Legal Cases: ['art 400', 'art 500', 'art 500', 'art 500', 'art 500', 'art 600', 'art 600', 'art 600', 'art 600', 'art 700', 'art 700', 'art 700', 'art 700']

KR102001991B1 - Method and apparatus for reducing latency of LTE uplink transmissions - Google Patents
Method and apparatus for reducing latency of LTE uplink transmissions Download PDF
KR102001991B1
KR102001991B1 KR1020187000897A KR20187000897A KR102001991B1 KR 102001991 B1 KR102001991 B1 KR 102001991B1 KR 1020187000897 A KR1020187000897 A KR 1020187000897A KR 20187000897 A KR20187000897 A KR 20187000897A KR 102001991 B1 KR102001991 B1 KR 102001991B1
KR1020187000897A
KR20180017141A (en
호세인 바게리
2015-07-14 Priority to US14/798,489 priority Critical
2015-07-14 Priority to US14/798,489 priority patent/US9717079B2/en
2016-06-02 Application filed by 모토로라 모빌리티 엘엘씨 filed Critical 모토로라 모빌리티 엘엘씨
2016-06-02 Priority to PCT/US2016/035552 priority patent/WO2017011086A1/en
2018-02-20 Publication of KR20180017141A publication Critical patent/KR20180017141A/en
2019-07-19 Publication of KR102001991B1 publication Critical patent/KR102001991B1/en
The method and apparatus reduce the latency of long term evolution (LTE) uplink transmissions. Configuration information regarding the downlink control information (DCI) message for physical uplink shared channel (PUSCH) transmission may be obtained. The DCI message may be received on the physical downlink control channel (PDCCH) in the first subframe. The DCI message may indicate a plurality of resource assignments in the second subframe for the uplink carrier, wherein the user equipment (UE) can select at least one resource allocation from it for transmission on the uplink carrier. The DCI message may be a cyclic redundancy check (CRC) scrambled by a radio network temporary identifier (RNTI) indicated via higher layers that are higher than the physical layer. Using selection criteria, a resource allocation can be selected from a plurality of resource assignments. A data packet may be transmitted on the PUSCH in the resource of the selected resource allocation in the second subframe for the uplink carrier.
This application claims priority from the filing date of Motorola Mobility's document number MM01559 and entitled " Method and Apparatus for Reducing Latency of LTE Uplink Transmission ", and Motorola Mobility's document number MM01560, entitled &quot; Method and Apparatus for Reducing Latency of LTE Uplink Transmissions &quot;, both of which are filed on the same day and are commonly assigned to the assignee of the present application, which is incorporated herein by reference.
The present disclosure relates to a method and apparatus for reducing the latency of Long Term Evolution uplink transmissions. In particular, this disclosure relates to resource selection for reducing the latency of long term evolution uplink transmissions.
Currently, wireless communication devices such as smart phones, cellular phones, tablets, personal computers and other devices communicate using wireless signals over networks such as Long Term Evolution (LTE) cellular networks. A large number of communications are sensitive to latency, which slows down the transmission rate of the data, such as communication delays. Unfortunately, due to negotiations that a communication device must perform with a base station to transmit data, there is latency in current systems. For example, in order to transmit data, the device must first request permission from the base station to transmit data, and then wait for permission before transmitting the data. This results in an undesirable latency of delaying communication between the communication device and the network.
Therefore, a need exists for a method and apparatus for reducing the latency of LTE uplink transmissions.
To illustrate the manner in which the benefits and features of the present disclosure can be obtained, the description of the present disclosure is made with reference to the specific embodiments thereof illustrated in the accompanying drawings. These drawings should not be construed as limiting the scope of the present invention, since they only illustrate exemplary embodiments of the present disclosure.
1 is an exemplary block diagram of a system according to a possible embodiment.
2 is an exemplary signal flow diagram illustrating signals between a wireless communication device and a base station that are required to transmit uplink packets using the current LTE uplink mechanism.
3 is an exemplary signal flow diagram illustrating signals associated with uplink packet transmission between a wireless communication device and a base station using a contention-based uplink mechanism according to a possible embodiment.
4 is an exemplary flow chart illustrating operation of a user equipment for a basic contention-based resource selection scheme in accordance with a possible embodiment.
5 is an exemplary flow chart illustrating operation of a wireless communication device in accordance with a possible embodiment.
6 is an exemplary flow chart illustrating operation of a wireless communication device in accordance with a possible embodiment.
7 is an exemplary flow chart illustrating operation of a wireless communication device in accordance with a possible embodiment.
8 is an exemplary block diagram of an apparatus according to a possible embodiment.
Embodiments provide a method and apparatus for reducing the latency of LTE uplink transmissions.
According to a possible embodiment, configuration information regarding a Downlink Control Information (DCI) message for Physical Uplink Shared Channel (PUSCH) transmission may be obtained. The DCI message may be received on the physical downlink control channel (PDCCH) in the first subframe. The PDCCH may be a PDCCH that is demodulated based on cell-specific reference signals, or an enhanced PDCCH (EPDCCH) that is demodulated based on dedicated reference signals, or an additional enhanced physical downlink control channel or combination thereof. have. The DCI message indicates a plurality of resource assignments in a second subframe for an uplink carrier, where a User Equipment (UE) can select one resource allocation from it for transmission on the uplink carrier . The DCI message may be a Cyclic Redundancy Check (CRC) scrambled by a Radio Network Temporary Identifier (RNTI) indicated via upper layers that are higher than the physical layer. The resource allocation may be selected from a plurality of resource allocations using a selection criterion. The data packet may be transmitted on the PUSCH in the resource of the selected resource allocation in the second subframe for the uplink carrier.
According to a possible embodiment, a DCI message may be received in the first subframe. The DCI message may indicate a resource allocation and modulation and coding scheme and may indicate a plurality of cyclic shifts in which the UE may select one cyclic shift for transmission in the second subframe for the uplink carrier can do. The cyclic shift can be selected from a plurality of indicated cyclic shifts, based on the selection criteria. A data packet is transmitted over the PUSCH in the resource indicated by the resource allocation and modulation and coding scheme, using a demodulation reference signal (DMRS) based on the cyclic shift selected in the second subframe for the uplink carrier .
According to a possible embodiment, an indication may be obtained, where the indication may indicate a set of frequency domain resource blocks for possible PUSCH transmission in the uplink subframe. A subset of the resource blocks may be selected from the set of frequency domain resource blocks for possible PUSCH transmission based on the selection criteria. The selection criteria may use at least a resource set size obtained from the instruction, use a modulo function, and use an identifier associated with the UE, wherein the modulo function is a function of "mod (a, b) b ", which can represent the remainder after dividing a by b. The PUSCH may be transmitted in a subset of the selected resource blocks in the uplink sub-frame. The time duration (or transmission time interval or subframe duration) for the PUSCH with reduced latency may be defined similar to a Rel-8 TTI size of 1 millisecond, or may be shorter, such as 1/2 millisecond , Which may be configurable by the network based on the desired latency reduction target or application. In another example, a frequency domain resource block for possible PUSCH transmissions for reduced latency may be defined the same as Rel-8 LTE, or it may be defined to correspond to a short transmission time interval such as 0.5 ms instead of 1 ms have. In a further example, the set of available resource blocks for possible PUSCH transmissions may be configured in a subset of sub-frames of possible uplink sub-frames only. For example, a set of resource blocks may be available in all alternative subframes, and RB0-RB6 may be available for PUSCH transmission in possible subframes indexed as 0, 2, 4 ..., The RB may have a duration of 1 millisecond.
1 is an exemplary block diagram of a system 100 in accordance with a possible embodiment. The system 100 may include a base station 120 such as a wireless communication device 110 such as a UE, an enhanced NodeB (eNB), and a network 130. The wireless communication device 110 may be a wireless terminal, a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a personal digital assistant, a device with a subscriber identity module, a personal computer, Or any other device capable of transmitting and receiving communication signals over a wireless network.
Network 130 may include any type of network capable of transmitting and receiving wireless communication signals. For example, the network 130 may be a wireless communication network, a cellular telephone network, a Time Division Multiple Access (TDMA) -based network, a Code Division Multiple Access (CDMA) An Orthogonal Frequency Division Multiple Access (OFDMA) -based network, a Long Term Evolution (LTE) network, a 3rd Generation Partnership Project (3GPP) -based network, Lt; RTI ID = 0.0 &gt; and / or &lt; / RTI &gt; other communication networks.
The uplink communication from the UE to the eNB may be performed in accordance with the LTE standard using single carrier FDM (A) (SC-FDMA) or DFT-spread OFDM (A) -SOFDM (A)) is used. In SC-FDM or DFT-SOFDM, block transmission of QAM data symbols is performed by first discrete Fourier transform (DFT) -diffusion (or precoding), followed by subcarrier mapping and by conventional OFDM modulators OFDM modulation. The use of DFT precoding may allow for a proper cubic metric / peak-to-average power ratio (PAPR), which may reduce the cost, size and power consumption of the UE power amplifier . According to DFT-SOFDM, each subcarrier used for uplink transmission may include information about all transmitted modulated signals, and the input data stream is spread through them. Uplink data can be transmitted using the PUSCH. Although the embodiments describe uplink packet transmission based on the LTE standard, it should be noted that the same techniques may be applied to uplink transmissions based on other modulation schemes and other transmission schemes such as conventional OFDM.
Embodiments can provide resource allocation and resource selection aspects of reduced latency LTE uplink transmissions. Reducing the latency for a user's data packets is an improvement such as a better user experience, reduced complexity such as reduced buffering requirements and other reduced complexities, and faster link adaptation / feedback, improved TCP performance and other enhanced performance Performance and can support new applications that may be sensitive to delays, such as augmented reality applications, automotive communications applications, and other applications that may be sensitive to delays.
For a UE in the RRC_CONNECTED (Radio Resource Control_Connected) state, the UE may find downlink grants in all downlink subframes, which may typically be a duration of 1 millisecond. When the eNB receives the packet to be transmitted to the UE, the eNB uses the control and data channels in the subframe, such as the PDCCH or EPDCCH and the Physical Downlink Shared Channel (PDSCH), in the next downlink subframe, Can be transmitted.
2 is an exemplary signal flow diagram illustrating signals between a base station 120, such as an eNB, and a wireless communication device 110, such as a UE, required to transmit uplink packets using the current LTE uplink mechanism. In the case of an uplink packet transmission, in signal 210, when the uplink buffer of device 110 is empty and device 110 receives an uplink packet in its buffer, typically in priority signal 220, The base station 120 must send a scheduling request (SR) to the base station 120 and then in the signal 230 the base station 120 transmits an uplink grant to the device 110, In signal 240, device 110 transmits a packet via the resources indicated by base station 120. Each of the three steps adds to the overall delay that the transmission of uplink packets may experience. Typically, the SR resource is a dedicated resource for the UE, which is configured with a certain periodicity, such as every 5ms / 2ms / 10ms. The latency for SR transmissions may be reduced by providing SR opportunities to the UE much more frequently, for example, by configuring a 2 ms periodicity for all UEs, but this will result in a significantly increased overhead on the uplink .
Figure 3 illustrates an uplink packet between a wireless communication device 110, such as a UE, and a base station 120, such as an eNB, using a contention-based uplink (CB-UL) Lt; / RTI &gt; is an exemplary signal flow diagram illustrating signals associated with transmission. At signal 310, base station 120 may send a contention-based uplink grant to device 110 via a broadcast or other message. At signal 320, device 110 may have an uplink packet ready to transmit. At signal 330, the device 110 may send the uplink packet to the base station 120 using information from the uplink grant. For example, embodiments may avoid latency due to SR for some uplink transmissions. This can be done by scheduling the CB-UL. In this case, the eNB may send an uplink grant in its cell, and any UE may prepare and transmit its uplink packet using its grant. The UE may embed specific information such as a Medium Access Control Identifier (MAC ID), a Cell Radio Network Temporary Identifier (C-RNTI), and other information in the packet, Thereby allowing the UE to determine whether it has transmitted a packet. In another example, a group of UEs configured for CB-UL and possibly addressed by UL authorization, by a contention-based RNTI (CB-RNTI), etc., Can be used.
The contention-based uplink grant may be transmitted using DCI formats 0 / 1A and / or 1C that support more compact payload sizes than some other DCI formats. Permissions may be sent in any search space, such as a Common Search Space (CSS) or a UE-specific Search Space (UESS). In some cases, the CB-UL-Downlink Control Information (CB-UL-DCI) format is adjusted to the size of the existing DCI format that the UE searches. If the CB-UL-DCI format size is not adjusted to the existing DCI format size, additional blind decodings may be supported by the UE. For example, four additional blind decodes in the common search space may be supported to support CB-UL-DCI. A special RNTI, such as a CB-RNTI configured via higher layers, may be used to distinguish the CB-UL-DCI format from other formats. Alternately, explicit fields may be included in DCI 0 / 1A and / or 1C to distinguish the CB-UL grant from other grants conveyed in DCI format.
Enhanced Physical Downlink Control Channel (EPDCCH) In the case of UESS, the UESS may be overlaid for a group of UEs. Thus, a CB-uplink grant may be sent in the UE-specific search space. At this time, the CB-uplink DCI format payload size may be adjusted to the DCI format 0 / 1A / payload size of the UE at the UESS.
According to a possible embodiment, the UE can transmit packets with a low latency. To transmit a packet, the UE may indicate to the network that it is interested and / or capable of supporting latency reduction on the uplink and the UE may send a DCI message for Physical Uplink Shared Channel (PUSCH) transmission Can be acquired. The base station may indicate that it can support latency reduction on the uplink via system information broadcast messages or using reserved fields or dedicated messages in the master information block. Upon receiving the indication, the UE can in turn direct the network that it can also support low latency. The base station can then transmit the configuration information to the UE via a system information broadcast message or a dedicated message. Alternatively, the network may implicitly or explicitly authorize the set of UE camped in the cell to operate in CB mode under conditions that have the capability to support latency reduction. The network can recognize this capability through UE category / capability information. The UE may be in a Radio Resource Control Connected (RRC_Connected) state and may perform Radio Resource Management (RRM) measurements such as measurements including path loss estimates and other measurements, Based on network commands, such as Timing Advance (TA) commands, and also based on the timing adjustments of the UE itself based on the downlink reception timing, Link time alignment can be maintained. The UE may then obtain information indicating a set or multiple sets of resources for possible contention-based (CB) PUSCH transmission via Media Access Control (MAC), RRC or other sources of information. The UE may also use a set of open loop power control parameters (P0, alpha, etc.) associated with transmissions of CB PUSCH transmissions, a set of modulation and coding scheme parameters, a redundancy version, Other information such as the virtual cell identity, and other information, can be acquired. When the UE has data in its UL buffer and the data is scheduled to be transmitted with a low latency, the UE searches the downlink control region and, via the DCI format 0/4 with the CRC scrambled with the C-RNTI of the UE, Lt; RTI ID = 0.0 &gt; 1 &lt; / RTI &gt; DCI message. The contention-based PUSCH transmissions can only be configured on the primary cell or on a subset of the cells configured for the UE.
If the UE fails to detect the intended DCI for the UE, the UE may detect the second DCI message with the second RNTI. For example, the UE may receive a second DCI message on a physical downlink control channel (PDCCH) in a first subframe. A second DCI message may indicate a plurality of resource assignments in a second sub-frame for a first carrier, wherein the UE selects one resource allocation from it for transmission over the first carrier. The second DCI message may be a cyclic redundancy check (CRC) scrambled by a radio network temporary identifier (RNTI) indicated via higher layers that are higher than the physical layer. For example, the second DCI message may indicate a plurality of resource assignments that are a subset of the resource assignments indicated by information obtained via MAC, RRC, and / or other DCI messages. The UE then uses the selection method to select a subset of UL resources from the set of resources for possible CB transmission in UL subframe n + k, where k is a frequency division duplex (FDD) 4, and k may be variable based on a TDD uplink / downlink (UL / DL) configuration, for example in Time Division Duplex (TDD). The selection method may include at least one of a number of resource blocks (RBs), an MCS index, a transmission block size, a demodulation reference signal (DMRS) cyclic shift, and a DMRS orthogonal cover code (OCC) sequence &Lt; / RTI &gt; The UE may then transmit the UL data by transmitting the PUSCH using the selected UL resources and associated parameters such as modulation and coding scheme, power control settings and other parameters. The UE may also embed its own identifier, such as a UE ID (UE ID) or C-RNTI, or other UE identifiers that the eNB may use to detect which UE has transmitted the associated PUSCH transmission. The UE may also include a buffer status report in the associated PUSCH. If the eNB successfully detects the PUSCH, the eNB may send a feedback to the UE using a Physical Hybrid-Automatic Repeat Request (ARQ) Indicator Channel (PHICH) Acknowledging the packet reception by sending an addressed explicit downlink message. The UE can then clear the contents of the UL buffer. The PUSCH transmitted based on contention-based resources may also be represented by a low latency PUSCH.
Embodiments may provide multiple resource assignments in a single grant. For example, a common search space, such as the PDCCH, can be overloaded and provide only a limited number of transmit opportunities, where only four grants can be sent, and the common search space (CSS) admit. Thus, in the case of a CB-uplink, a single CB-based grant may schedule an uplink over multiple uplink resources in a given subframe. When the extra blind decodings are allowed to accommodate the CB uplink transmissions, the extended common search space may be updated by the additional candidates for aggregation levels 4 or 8 and / May be defined using a System Information Radio Network Temporary Identifier (SI-RNTI) or a CB-RNTI. A new common search space with different aggregation levels (e.g., 2, 4, 8, 16) may be defined for the EPDCCH.
A first example of CB-grant fields indicating a plurality of resource assignments may include a 0/1 A differentiation field. The CB-grant fields may include fields for a first resource allocation, including a frequency hopping flag, an RB assignment field, an MCS, a TPC for PUSCH, and a cyclic shift for DMRS and an OCC index. The CB-grant fields may include fields for frequency hopping flags, RB allocation, MCS, TPC for PUSCH, and second resource allocation including cyclic shift and OCC index for DMRS. The CB-grant fields may also include a resource allocation (RA) type. These fields may be part of the DCI message. To maintain a consistent DCI message size, the fields of current DCI messages that are not useful for CB-granting may be replaced with additional CB-grant fields. Table 1 illustrates exemplary fields and descriptions of DCI format 1A. Exemplary fields that may be replaced with CB-grant fields include an NDI field, a TPC field for the PUSCH, a cyclic shift and OCC index field for the DMRS, a CSI request field, and other fields. Table 1 also illustrates exemplary fields and description of DCI format 1C, where the number of bits of 1C may be 12 bits (5 MHz), 13 (10 MHz), 15 (20 MHz) or any other useful number of bits.
In the second example, one or more permissions may be cocoded to reduce the payload or to grant permission to existing UL DCI payloads. In this example, the CB-grant fields may include a 0 / 1A differential field. In addition, the CB-grant fields may include fields for interpreting joint assignments, joint frequency hopping flags, joint RB assignment fields, joint MCS, joint transmit power control (TPC) for PUSCH, and DMRS and OCC index selection And fields for first and second resource allocation, including joint cyclic shifts. The CB-grant fields may also include an RA type.
To illustrate the example in detail, there may be a field that interprets the joint assignment, which may be set to 0 to indicate that there is no second resource allocation. If the field is set to 1, it may imply that there is a second resource allocation in the grant. If the RB allocation field indicates that RB0 and RB1 are part of the first resource allocation, the second resource allocation may be the next two resource blocks RB2 and RB3. The joint MCS field may indicate that a single MCS is used for both resource allocations. A UE receiving such an uplink grant may select a resource allocation of one of the resource allocations based on a random selection or using a predetermined set of rules. For example, if the number of RBs for each resource allocation is not equal, the UE may select a resource allocation based on its uplink buffer status. The UE may also select a resource allocation based on a path loss value threshold. The threshold may be configured via higher layer signaling.
Embodiments can provide autonomous selection of UEs from contention-based resource areas. For example, to reduce latency for uplink packets, the eNB may configure a frequency domain within a set of resource blocks or uplink system bandwidths in the uplink, via higher layers or the like. These resources may be used by any UE or set of UEs to transmit on the uplink, which may include a Buffer Status Report (BSR). Resources can be advertised in SIB, RRC messages and / or any other useful message, and can be used by the UE whenever it wants to send a packet at low latency without having to wait for SR transmissions, or in other useful instances. For example, the UE may obtain an indication from the eNB indicating a set of frequency domain resource blocks for possible PUSCH transmission in the uplink sub-frame.
The configured resources can be implicitly indicated. For example, resources used for Device to Device (D2D) or side link operation may also be used to indicate resources used for uplink resources advertised. In the case of TDD Enhanced Interference Mitigation and Traffic Adaptation (EIMTA), the set of uplink resources used for the CB-uplink is determined by the TDD configuration corresponding to the DL-reference UL / DL configuration May be limited to the indicated uplink subframes. In another option, the set of UL resources used for CB-uplink is determined using a UL / DL configuration indicated by a dynamic UL / DL configuration indicated in DCI format 1C with CRC scrambled by EIMTA-RNTI . In another example, resources may be dictated by RACH resources / configuration. Since the RACH resources are allocated by the cell and serve UE camped in the cell, the number of UEs attached to that cell can be implicitly considered. Thus, the information may be used to allocate the number of CB-UL resources. For example, the CB-UL resources may be determined based on a formula that takes into account the RACH configuration.
As another example, a subset of the RACH resources may be reused for CB-UL resources. In one simple example, all PRACH resources can be re-used as CB-UL resources. For example, the PRACH configuration index 45 may enable 6 RB resources per odd subframe that can be reused for CB UL transmissions. In this particular example, additional signaling may not be required to notify UEs about CB-UL resources. This approach may require additional detection processes on the eNB side.
The eNB may configure, via higher layers, etc., a Modulation and Coding Scheme (MCS) and / or a set of transmission block sizes that the UE may use to transmit uplink packets to the configured resources . Alternatively, such an arrangement may be fixed in the specifications, for example, when the contention-based uplink is used to transmit a BSR or other fixed size payload. The MCS and / or TBS may also depend on other parameters, such as, for example, the channel quality of the link between the UE and the eNB, in the case of TDD operations where reciprocity can be assumed. The eNB may also configure a set of cyclic shifts and / or cover code sequences that may be used by any UE, such as higher layers, to transmit the DMRS with uplink packets to the configured resources.
The eNB may additionally configure a set of PHICH resources for transmission of ACK / NACK feedback information associated with uplink transmissions in configured resources, etc., via higher layers, etc., Can be used to receive feedback on its uplink transmission. The eNB can further configure a separate set of power control configuration parameters such as P0, alpha and other power control settings that the UE uses to transmit on the uplink to the configured resources have. The eNB may also dynamically control the use of upper layer configured uplink resources via physical and / or MAC layer signaling.
According to a first implementation, an eNB may configure a set of resource blocks (e.g., RB0, RB1, RB2, RB4) for a contention-based uplink and the eNB may select a resource block It can be expected to transmit through the resource block. The UE is based on the UE's C-RNTI, sub-frame number, system frame number, set configuration index, UE-eNB link quality, determined cyclic shift (CS) and orthogonal cover code (OCC) A resource block may be selected based on a hashing function that can be performed. For example, the UE may select one RB of the set of RBs indexed by (L * M + C-RNTI + SFN) mod N_RBs, where L is {0,1,2, ... N_RBs- 1}, N_RBs is the number of RBs in the set of RBs, M is a constant, and M and N_RBs are relatively prime to each other.
According to a second implementation, the eNB may configure a set of starting resource blocks (e.g., RB0, RB1, RB2, RB4) for the contention-based uplink, It can be transmitted over L consecutive resources starting from one. The allowed values of L may be preconfigured or signaled via higher layers and the UE may select a particular value of L based on a packet or a Transport Block (TB) attempting to deliver to the eNB. For example, if the UE wishes to carry a 15 byte transmission block, according to a 24 bit CRC, the number of information bits may be 15 * 8 + 24 = 144 bits, and one RB (14 x 14 = 144 RE ), The QPSK modulation may correspond to a coding rate of 1/2. If the UE has a packet size of 33 bytes, it may choose to transmit the TB using 2-RB allocation to achieve the same coding rate of 1/2. The UE may use a first orthogonal cover code (OCC) for 1-RB allocation and a second orthogonal cover code for 2-RB allocation. The CSs used by the UE for 1-RB and 2-RB allocation may be the same or different.
According to a third implementation, the eNB may include a set of resource blocks (e.g., RB0, RB1, RB2, RB4) for a contention-based uplink, a set of resource allocations A set of MCSs (QPSK-rate-1/2, QPSK, rate-3/4, 16QAM-rate-1/2, etc.), and a set of transport block sizes (TBS) 6 bytes of TCP-ACK with L3 header, 320 bits of VoIP packet, etc.), a set of cyclic shifts (a subset from the allowed set), and / or other configurations. The UE may select from a set of allowed combinations based on its requirements such as the amount of uplink data to be transmitted and may determine at least the C-RNTI, sub-frame number, system frame number, set configuration index and / A hashing function may be used that depends on at least one of the information.
According to a fourth implementation, the eNB has multiple sets of contention-based uplink resources, each set having one of the starting resource blocks (e.g., RB0, RB1, RB2, RB4) A set of MCSs (QPSK-rate-1/2, QPSK, rate-3/4, 16QAM-rate-1/2 etc.), a set of TBSs (Six bytes of TCP-ACK with additional L2 / L3 headers, 320 bits of VoIP packets, etc.), a set of cyclic shifts (a subset from the allowed set), and / or other configurations. The UE may select one set from a plurality of sets based on its requirements such as the amount of uplink data to be transmitted and determine from the set at least a C-RNTI of the UE, a subframe number, a system frame number, A configuration index, and / or other information based on a hashing function that depends on at least one of the information. Each set may be associated with a resource allocation. For example, the first set may have only one RB allocation, the second set may have only two RB allocations, and so on.
The implementations illustrate methods by which an eNB may configure resources at an upper layer and may rely on eNB blind decoding in a set of allowed resources to detect uplink transmissions from UEs using these resources. The number of blind decodings may be limited. For example, the transmission length of the RBs may be indicated to the eNB via implicit / explicit indications. An example of an explicit indication may be a respective first "m" bit, and a subset of RB (s) may be assigned to indicate an RB index. The RB index can illustrate how many RBs are used for this transmission. In another example, a subset of RBs may be used for a single RB transmission and another subset may be used for two RB transmissions, and so on. For example, although all CB-RBs may be used for a single RB transmission, two RB transmissions may only be allowed for certain resources, and so on.
According to a fifth implementation, the eNB has multiple sets of contention-based uplink resources, each set having one of the starting resource blocks (e.g., RB0, RB1, RB2, RB4) A set of MCSs (QPSK-rate-1/2, QPSK, rate-3/4, 16QAM-rate-1/2 etc.), a set of TBSs (Six bytes of TCP-ACK with additional L2 / L3 headers, 320 bits of VoIP packets, etc.), a set of cyclic shifts (a subset from the allowed set), and / or configurations. The UE may select one set from a plurality of sets based on its own requirements, such as the amount of uplink data to transmit, and / or based on at least physical layer signaling. Thus, the eNB may control contention-based resources based on physical layer signaling. Physical layer signaling may be based on one or more fields in a common DCI that are transmitted over a control channel. For example, the DCI may have a 1-bit indicator associated with the set indicating whether the UE can use the set in the corresponding subframe or not. For example, if the UE receives DCI in downlink sub-frame n, the corresponding fields may be applied in uplink sets in a predetermined uplink sub-frame in sub-frame n + 4 or n + k, Where k may be signaled by the eNB or based on the UE capabilities indicated in the network or based on a set of configurations such as a TDD configuration. An example is shown in Table 2. In another example, for example, the DCI may have a 1-bit indicator associated with each set indicating whether the UE can use the set in the corresponding subframe or not.
Based on the above, similar fields may also be used to control the MCS indicator, the TBS indicator, and other information shown in Table 3, although only two bits may be appropriate for the DCI format.
According to a sixth implementation, the resources may be part of an RB in the time domain. For example, the UL portion of the TDD special subframe (s) may be configured as a CB resource.
The eNB may configure a set of resource blocks for the contention-based grant area. The UE performs a hashing function to determine the number of RBs and RBs starting from the set. One of the four RRC signaled sets may be as follows.
1. {RB3-6 (Slot 1), RB94-97 (Slot 2)}
2. {RB13-16 (slot 1), RB84-87 (slot 2)}
3. {RB23-26 (slot 1), RB74-77 (slot 2)}
4. {RB33-36 (Slot 1), RB64-67 (Slot 2)}
This set may be defined such that the UE performs frequency hopping across the slots for frequency diversity. Permissions may signal allowed sets, and the UE may select resources from the allowed sets based on a hashing function. Permanent resources may be allocated, such as one set per subframe, and the set in a given subframe may be a function of the subframe index. In addition, the eNB may signal multiple sets in a subframe using dynamic signaling. The subset of TB sizes and / or resource allocation sizes allowed for contention-based grants may be configured by the eNB. A subset of the MCS allowed for contention-based grants can be configured by the eNB. If the UE has already transmitted a number of packets in a plurality of subframes, such as consecutive subframes, the UE may allow other UEs to use the resource. For example, the UE may perform some backoff, or may transmit with a lower probability than prior attempts. The eNB may configure the probability that the UE will transmit in multiple subframes. The UE may transmit a contention-based uplink transmission in a subframe only if there is no uplink grant, such as a UE-specific grant for transmission in the subframe.
The eNB may construct a set of resource blocks for a contention-based grant area using bitmap instructions, such as through higher layers, etc., where the bitmap directive may indicate whether a particular resource block belongs to a contention- Can be indicated. For example, if the uplink system bandwidth corresponds to 100 resource blocks (indexed to RB0, RB1, ... RB99), then the contention-based grant area is a 100-bit bitmap (b0, b1, ..., RB99). , b99), and if bit b0 is set to 1, then the corresponding resource block RB0 may belong to the contention-based grant area, otherwise, RB0 may be assigned to the contention- It may not belong.
In another example, the upper layer may indicate parameters that may be used to derive the corresponding bitmap, such as indicating the resource block offset and the number of resource blocks. For example, if the eNB has a first offset (O1), a number of resource blocks (N1) and a second offset (O2) of O1 <= x <O1 + N1 or O2-N1 < , The resource block (RBx) belongs to the contention-based area. If the uplink system bandwidth corresponds to 100 resource blocks (indexed by RB0, RB1, ... RB99), if the upper layers indicate O1 = 10, O2 = 25 and N1 = <15, or 20 <x <= 25, RBx (0 <= x, 99) belongs to the contention-based permission area, that is, the RBs belonging to the contention-based area {RB10, RB11, RB12, RB13 , RB14, RB20, RB21, RB22, RB23, RB24}.
4 is an exemplary flowchart 400 illustrating the operation of a UE for a basic CB resource selection scheme in accordance with a possible embodiment. At step 410, a flowchart may begin. In step 420, the UE may determine whether it has UL data in its buffer. If the UE has UL data in its buffer, at step 430, the UE may determine whether it has received a UL grant CRC scrambled with a C-RNTI. If so, in step 440, the UE may transmit in the resources indicated by the UL grant. If not, in step 450, the UE may determine whether there are possible CB UL resources available in the subframe. If yes, at step 460, the UE may select a CB resource, and at step 470, the UE may transmit on the selected resource. At step 480, the flowchart may end.
Embodiments may provide resource selection, such as selection of a subset of resource blocks, using a hashing function. For example, an uplink resource set, such as a set of frequency domain resource blocks , may include a set of uplink resources, such as resource blocks numbered from 0 to N CCE, k -1, where N CCE, k May be the total number of resources configured in the set in subframe k. The set of UL resource candidates that the UE can transmit may be in terms of resource spaces, where the resource space at resource aggregation level L, such as L {{1,2,4,8}
May be defined by a set of UL resource candidates. Resource space
The UL resources corresponding to the UL resource candidate m of &lt; RTI ID = 0.0 &gt;
Where Y k can be defined as described below, i = 0, ..., , L-1. For a common resource space, m '= m. For UE specific resource space, m '= m, where m = 0, ... , And M (L) -1. M (L) may be the number of UL resource candidates that the UE may be allowed to transmit on a given resource space. In the first example, the UE may be allowed to select from a set of resource candidates as shown in Example 1 of Table 4, where each resource candidate may correspond to a subset of the resource blocks. In the second example, the UE may obtain a resource candidate for direct transmission as shown in Example 2 of Table 4. [ The RA levels that define the resource space are also listed in Table 4.
For the common resource space, Y k can be set to zero. In some cases, the common resource space may not be needed, or the UE may have a fixed payload to transmit, etc., then the common resource space may be used for other purposes.
UE-specific resource space at RA level L
, The variable Y k can be defined by:
Where the exemplary values may be Y -1 = n RNTI ≠ 0, where A and D are relatively large prime numbers such as A = 39827, D = 65537, and k =
And n s may be the slot number in the radio frame. The slot number may be the slot number of the UL subframe in which the UE transmits the uplink. For multi-RB allocations, the RB allocations may be continuous or non-contiguous based on the configuration of the uplink resource set. The RNTI may be indicated via higher layers and may be the same as or different from the C-RNTI of the UE.
The second uplink resource set may also be composed of a set of its uplink resources. The set of uplink resource candidates and the RA levels may be individually defined or configured for each uplink resource set. The variable Y k may also be defined individually for each uplink resource set if A = 39829, and so on. Other hashing functions based on EPDCCH hashing and the like may also be used to determine UL resource candidates. Note that the UE may be composed of multiple sets of uplink resources and may apply the hashing functions described herein individually in each set of uplink resources. In a given subframe, the UE may select an uplink resource set based on random selection or based on the number of resource blocks the UE has decided to transmit.
Embodiments may provide a Scheduling Request (SR) operation under CB-UL transmission. For example, if the UE has already sent in the CB-UL resource but has not received the acknowledgment, the UE may send a scheduling request for the SR resource. When the UE receives an acknowledgment for the UL transmission in the CB resource, the UE may release the SR resource and stop the scheduling request (re) transmission, depending on factors such as data type. In one example, the UE may be configured with an SR and may use CB-UL resources. The UE may be configured to select between SR and CB-UL usage based on its uplink buffer status. For example, if the uplink buffer is smaller than the threshold, the UE may use the CB-UL. Alternatively, the UE may use the SR to initiate transmission of its uplink data. In another example, the UE may always select SR to send delay-tolerant uplink data to the eNB. In another example, the UE may select a first available opportunity, i.e., a CB-UL or SR transmission opportunity, which occurs first, to initiate transmission of an uplink packet.
Embodiments may provide multiple cyclic shifts and / or orthogonal cover code sequences in a single grant. For example, the eNB may use Space Division Multiple Access (SDMA) or Multiple User Multiple Input and Multiple Output (MU-MIMO) to improve uplink efficiency. . Although it can do so by scheduling UEs with the same time-frequency resources, it is spatially separated by configuring users to transmit DMRS with different cyclic shifts. CB-UL can also improve reception of CB-UL transmissions using the same technique. In this technique, the UE may be configured to select a cyclic shift from a set of allowed cyclic shifts. For example, the UE may select from 8 cyclic shifts for a given DCI format 0 uplink transmission. The exact value of the cyclic shift used by the UE may be indicated in DCI format 0 through the "Cyclic Shift and OCC Index for DMRS" of the 3-bit field. The eNB may indicate a plurality of cyclic shift values via downlink grant.
In the first example, the eNB may send a single downlink message comprising one MCS (MCS0) and a resource block allocation (RB0) and two or more cyclic shift values (CS0, CS1, CS2). Upon receiving the message, the UE can select one of the cyclic shift values (one of CS0, CS1, CS2) based on the selection criterion and transmit via resource block allocation RB0 using the indicated MCS value (MCS0) can do. The second UE may select one of the cyclic shift values (one of CS0, CS1, CS2) based on the selection criteria and transmit via resource block allocation RB0 using the indicated MCS value MCS0 . Thus, UEs can select different cyclic shift values and transmit on the same resource blocks.
In the second case, the eNB may send a first downlink message, such as a DCI, which includes one MCS (MCS0) and a resource block allocation (RB0). The eNB may transmit the second message via the RRC or the like, and this second message may indicate a set of cyclic shift values (CS0, CS1, CS2). Upon receiving the first message, the UE may select one of the cyclic shift values, such as one of CS0, CS1, CS2 based on the selection criteria, where these values may be obtained from the second message and the indicated MCS value (RB0) using resource block allocation (MCS0). The second UE may select one of the cyclic shift values, such as one of CS0, CS1, CS2 based on the selection criteria, where these values may be obtained from the second message and use the indicated MCS value (MCS0) And transmit it through resource block allocation (RB0). Thus, UEs can select different cyclic shift values and transmit on the same resource blocks.
In another example, the eNB may construct a plurality of sets of cyclic shifts and / or orthogonal cover code sequences via higher layers and may include cyclic shifts that may be used in a given subframe and / And may indicate a particular set of code sequences. Table 6 gives examples of directions. For example, if the UE receives a DCI indicating a Cyclic Shift Indication field of '10', the UE may select one value from {CS0, CS1, CS2} based on the selection criteria to transmit its DMRS have. The at least one set may comprise a plurality of cyclic shifts.
Embodiments can provide a selection of uplink resources from multiple grants based on the UE &apos; s coverage and eNB signaling. For example, the eNB may send a number of contention-based uplink grants targeted towards UEs of different coverage levels in the cell. For example, an eNB may support UEs in poor coverage by sending a compact CB-UL grant based on DCI 1C, etc., using a smaller payload size, and the eNB may be able to support UEs in poor coverage A large payload size can be used to transmit a non-compact CB-UL grant based on DCI 0 / 1A or the like. In this case, the permissions can be used appropriately by the UE based on its coverage level. For example, the UE may appropriately select the correct uplink grant for transmission using its downlink path loss measurements and, optionally, the relative threshold indicated by the eNB. Thus, when the UE detects a plurality of CB-UL grants with different payload sizes, the UE may use a UL grant to be used based on a predetermined set of rules including, for example, coverage level, downlink measurements, Can be selected. If the UE detects multiple CB-UL grants with the same payload size, the UE may randomly select one of the grants, or each grant may have an associated probability metric such as embedded in the DCI , Which may be used by the UE to determine which grant to use. Exemplary authorizations are shown below. An exemplary grant may include a 0 / 1A differential field, a frequency hopping flag, an RB assignment field, an MCS field, a TPC field for PUSCH, a cyclic shift for DMRS and an OCC index selection field, a probability field, and an RA type field. A probability field such as a 2 bit field may indicate one of four values such as 0.25, 0.5, 0.75 and 1, indicating the probability that the UE is able to transmit on the uplink resource indicated by the grant have.
As another example, for UEs with different coverage, the set of CB-UL resources, such as signaled via higher layer signaling, may be different. For example, the UEs may transmit RSRP measured in subframes including specific subframes as indicated by higher layers, or nearly empty subframes or discovery reference signals, to a signaled / specific threshold And may be closer to the center of the cell. Closer UEs may obtain a larger set of CB-UL resources, but UEs further away from the cell center may obtain smaller, including the case of an empty set of CB-UL resources configured for contention.
Embodiments may provide UE detection at the eNB from the received uplink. For example, if a UEID or C-RNTI is embedded in a MAC message, the eNB may once detect the uplink TB is successfully decoded. Alternatively, the UE may transmit its C-RNTI as uplink control information together with the data via the PUSCH. In this case, when the Uplink Control Information (UCI) is associated with the CB-UL, the eNB indicates individual parameters such as delta parameters to determine the number of REs to transmit the UCI . The C-RNTI may be encoded in 8-bit or 16-bit CRC as well as some additional information such as information from the BSR and / or associated contention-based uplink grant.
The scrambling may be based on cyclic shift and / or OCC index and / or other parameters selected by the UE from the control message or may use the CB-RNTI. For example, a scrambling sequence for uplink PUSCH transmission may be generated using:
Where c init may be an initialization seed that is used for scrambling sequence generator for a PUSCH transmission, n RNTI may indicate an RNTI, n s may indicate a slot number,
(Cs) is the cyclic shift (cs) associated with the uplink transmission, and q may be a cell identifier that may be a virtual cell ID, where q is a MIMO codeword index (e.g., q = 1 for a single codeword transmission) ) And / or a function of the orthogonal cover code sequence. As a first example, the function f (cs) = cs. As a second example, the function f (cs) = 2 x cs, where x may be signaled in the specification or may be an integer greater than zero fixed.
Embodiments may provide PHICH / HARQ retransmissions for a contention-based uplink. For example, if the eNB detects a cyclic shift based on the DMRS, but fails to detect the uplink data, such as when the CRC fails, the eNB may request a retransmission on the downlink The detected cyclic shift can be signaled. For example, if the eNB knows based on a hashing function that a particular UE may have transmitted using a particular resource with a particular cyclic shift, then the eNB will only use the dedicated Resources can be transmitted. However, if the eNB fails to detect any transmission on the contention-based resource on the uplink, the eNB may assume that the corresponding resource has not been used. Although the eNB detects that there was a transmission on the contention-based resource, it fails to detect the uplink data, such as when the CRC fails, or even detects the UE that reliably used the DMRS cyclic shift or a particular cyclic shift The eNB may indicate through the NACK or the like that the uplink transmission has failed using the PHICH resource corresponding to the uplink contention-based resource, and thus the UE may then handle the packet failure It is possible to rely on other means. For example, the UE may retry to send a packet on another contention-based resource, or the UE may receive a dedicated resource from the eNB after a longer delay that it may use to transmit the packet.
The LTE uplink HARQ can support both synchronous, adaptive and non-adaptive (re) transmission (s). In the case of FDD, eight HARQ processes can be defined in the uplink for the single-codeword transmission mode and sixteen HARQ processes for the two-codeword transmission mode. In any transmission mode, for a contention-based uplink, the UE is likely to use a single codeword transmission mode. In the case of contention-based transmissions, a separate HARQ process (s) may be specified in addition to the normal HARQ processes. As another alternative, the same HARQ process may be shared between contention-based versus non-contention based transmissions. A NACK on the PHICH resource corresponding to the uplink contention-based resource may indicate to the UE that the corresponding uplink transmission has failed and the UE may have to retry sending the packet again. One or more consecutive NACKs on the PHICH for the UE may trigger an SR from the UE.
Embodiments may provide power control. For example, a power adjustment in response to a UE transmission on a particular resource on which the CB uplink occurs can be signaled by the eNB. The TPC-CB-RNTI may signal adjustments for multiple resource assignments, such as the starting RB location in the CB resource pool. For example, for UE transmissions in subframe n on the CB-UL resource, the power adjustment may be sent in subframe n + 4, which may be used by the UE for subsequent CB-UL transmissions. The coordinating steps may be different from the steps used for non-contention-based UL resources.
According to a possible example of power control, the UE may receive higher layer signaling, such as via MAC or RRC, indicating a set of resources for possible contention-based (CB) PUSCH transmission. The UE may also receive upper layer signaling indicating the open loop power control parameters that the UE may use for CB transmission. The parameters may include P0 and alpha, such as P0 and separate values of alpha for CB transmission. If the UE has data in its own buffer, in each DL sub-frame n in which the PDCCH / EPDCCH is monitored, the UE may transmit the DCI format 0/4 intended for the UE by a DCI CRC scrambled with the UE's C-RNTI You can check.
If the UE does not detect the intended DCI for the UE, the UE may use the selection method to select a subset of UL resources from the set of resources for possible CB transmission in the UL subframe n + k. The selection method may include the UE selecting one or more of a TB size, a number of RBs, an MCS index, a DMRS cyclic shift, and a DMRS orthogonal cover code sequence. To determine the transmit power for the CB-PUSCH transmission, the UE sends a TPC command corresponding to a higher layer parameters such as P0 and alpha configured for CB transmission and a subset of UL resources selected for the CB-PUSCH transmission by the UE Lt; RTI ID = 0.0 &gt; TPC &lt; / RTI &gt; The TPC command may be received by the UE via a PDCCH message with DCI format 3 / 3A. The DCI CRC is scrambled with an identifier associated with a CB-PUSCH transmission such as CB-TPC-PUSCH-RNTI. A PDCCH message with DCI format 3 / 3A may be received by the UE in subframe n for CB-PUSCH transmission, etc., in subframe n + k, and the UE may transmit the subframe n The DCI format 3 / 3A received from &lt; / RTI &gt; Alternatively, if the UE is configured by higher layers as a set of resources for possible CB PUSCH transmissions, the UE may begin monitoring the DCI format 3 / 3A with the CRC scrambled by the CB-TPC-PUSCH-RNTI have. The DCI may include TPC commands for a plurality of subsets of resources in a set of resources for possible CB transmission. The UE can maintain a separate TPC state for each subset and update it based on the TPC commands in each received DCI format 3 / 3A with the CRC scrambled by CB-TPC-PUSCH-RNTI have. If the UE selects a particular subset for PUSCH transmission, the UE may use its TPC state for that subset with the open-loop parameters to set its PUSCH transmit power for its transmission in a subset of that resource have.
If the UE detects an intended DCI for the UE, the UE may use the RA Assignment field of the DCI to determine UL resources for PUSCH transmission in UL subframe n + k. The transmit power used by the UE for PUSCH transmission is determined by the open loop power control parameters configured by the upper layers for regular PUSCH transmissions and the TPC adjustments received at the DCI, such as the DCI, And any TPC adjustments received at DCI 3 / 3A with a CRC scrambled by-PUSCH-RNTI. The variable k may be a fixed number in the specifications. For example, in the case of the LTE FDD frame structure, k = 4. For an LTE TDD frame structure, k may depend on the particular UL / DL configuration for the UE and may be, for example, 4 or 6.
In an event where there is a conflict between the side link resources and the CB-UL resources, the side link UE may drop the side link operation. For example, the UE may drop the transmission or reception of the side link signal at the CB-UL resource.
FIG. 5 is an exemplary flow chart 500 illustrating operation of a wireless communication device 110, such as a UE, in accordance with a possible embodiment. The flowchart 500 can be used to signal multiple resource allocations via a single grant. At step 510, flowchart 500 may begin. At step 520, configuration information regarding a downlink control information (DCI) message for physical uplink shared channel (PUSCH) transmission may be obtained.
In step 530, a DCI message may be received on the physical downlink control channel (PDCCH) in the first subframe. The DCI message may indicate a plurality of resource assignments in the second subframe for the uplink carrier, from which the UE may select one resource allocation for transmission on the uplink carrier. The DCI message may be a cyclic redundancy check (CRC) scrambled by a radio network temporary identifier (RNTI) indicated via higher layers that are higher than the physical layer. The UE may also have a cell radio network temporary identifier (C-RNTI) and a contention-based cell radio network temporary identifier (CB C-RNTI) configured via higher layers, and the DCI may be scrambled by CB C-RNTI . Each resource allocation of a plurality of resource allocations may have the same number of resource blocks. The number of resource assignments may be explicitly or implicitly indicated in the DCI message. In addition, the resource assignments may be in an uplink grant. For example, the DCI message may include a plurality of uplink grants, each of which may include at least one resource assignment. The resource allocation may include resource blocks, other information such as transmit power and reference signaling, and / or other information useful for transmitting on the UL. Occasionally, uplink grants may have different information beyond resource assignments.
In step 540, the resource allocation may be selected from a plurality of resource assignments using a selection criterion. The selection criteria may be a random resource allocation selection from a plurality of resource assignments. The selection criterion may also be based on at least one parameter measured by the UE. For example, the selection criteria may be based on measured parameters such as downlink reference signal received power (DL RSRP), signal propagation path loss, uplink buffer status, and / or any other useful parisellites. Also, the UE may have a UE identifier, and the selection criteria may be based on a hashing function based at least on the UE identifier.
In step 550, parameters may be determined for transmission of the data packet. According to a possible embodiment, the UE may have a cell radio network temporary identifier (C-RNTI), and a cyclic shift and / or orthogonal cover code (OCC) sequence may be provided for demodulation reference for transmission of data packets based on C- Can be determined for the signal DMRS. In some embodiments, the orthogonal cover code (OCC) sequence may be fixed or predetermined. According to another possible embodiment, the cyclic shift and / or orthogonal cover code (OCC) sequence may be determined for the DMRS for transmission based on at least one field indicated in the DCI message. According to another possible embodiment, a cyclic shift may be determined for the DMRS for transmission, and scrambling initialization for PUSCH transmission may be selected based on at least a cyclic shift determined for the DMRS for transmission. According to another possible embodiment, an orthogonal cover code (OCC) sequence may be determined for the DMRS for transmission and a scrambling initialization for PUSCH transmission is based on at least an orthogonal cover code (OCC) sequence determined for the DMRS for transmission Can be selected.
At step 560, a data packet may be transmitted on the PUSCH in the resource of the selected resource allocation in the second subframe for the uplink carrier. At step 570, the flowchart 500 may be terminated.
FIG. 6 is an exemplary flowchart 600 illustrating operation of a wireless communication device 110, such as a UE, according to a possible embodiment. The flowchart 600 can be used to signal multiple cyclic shifts with a single grant. At step 610, a flowchart 600 may begin. At step 620, configuration information regarding a downlink control information (DCI) message for physical uplink shared channel (PUSCH) transmission may be obtained.
In step 630, a DCI message may be received in the first subframe. The DCI message may indicate a resource allocation and modulation and coding scheme and may indicate a plurality of cyclic shifts in which the UE may select a cyclic shift therefrom for transmission in the second subframe for the uplink carrier . The number of cyclic shifts in the plurality of cyclic shifts indicated in the DCI message may be 2 or any other number of useful cyclic shifts. The DCI message may implicitly indicate the number of cyclic shifts in the plurality of cyclic shifts from which the UE may select one cyclic shift for transmission. The DCI message may be received on the physical downlink control channel (PDCCH) in the first subframe. The DCI message may indicate a resource allocation and modulation and coding scheme and may indicate a plurality of cyclic shifts in which the UE may select one cyclic shift from it for transmission. The DCI message may be a cyclic redundancy check (CRC) scrambled by a radio network temporary identifier (RNTI) indicated via higher layers that are higher than the physical layer. In addition, the indication for the plurality of cyclic shifts may comprise an indication for a plurality of cyclic shift and orthogonal cover code (OCC) sequence pairs. The first cyclic shift may be indicated using the Cyclic Shift and OCC Index fields for the demodulation reference signal (DMRS) of the DCI message. The second cyclic shift may be indicated using a field used for transmit power control (TPC) for the physical uplink shared channel (PUSCH) and a field used for the new data indicator (NDI) . This may allow 3 bits to indicate a second cyclic shift. Cyclic shifts may also be indicated using any other useful fields or information.
In step 640, the cyclic shift may be selected from a plurality of indicated cyclic shifts based on the selection criteria. The cyclic shift and OCC sequence pairs may be selected from a plurality of indicated cyclic shift and OCC sequence pairs based on the selection criteria. At step 650, scrambling initialization may be selected for PUSCH transmission based on at least a cyclic shift selected for the DMRS.
In step 660, a demodulation reference signal (DMRS) based on the cyclic shift selected in the second subframe for the uplink carrier is used to demultiplex the physical uplink shared channel The data packet can be transmitted via the PUSCH. The data packet may be transmitted on the PUSCH using the DMRS based on the selected cyclic shift and OCC sequence pair. At step 670, flowchart 600 may be terminated.
FIG. 7 is an exemplary flowchart 700 illustrating operation of a wireless communication device 110, such as a UE, in accordance with a possible embodiment. The flowchart 700 may be used for transmission by selecting from a set of higher layer configured resources for signaling multiple resource allocations, etc., and the UE may select a resource allocation based on the selection criteria. At step 710, flowchart 700 may begin.
At step 720, an indication may be obtained indicating a set of frequency domain resource blocks for a possible physical uplink shared channel (PUSCH) transmission in the uplink subframe. For example, the resource set size may be the number of resource blocks for possible PUSCH transmissions. The subset of resource blocks may be the first subset of resource blocks. The set of frequency domain resource blocks may be smaller than the uplink transmission bandwidth configuration. For example, the uplink transmission bandwidth configuration may be uplink system bandwidth. The indication may be an upper layer message from a layer higher than the physical layer. For example, the upper layer message may be an RRC message, a MAC message, or any other upper layer message, or the indication may be in a physical layer message. For example, the indication may include at least a physical layer message. The indication may be implicitly indicated through a RACH configuration or may be indicated in other ways. The indication may also be a bitmap indication indicating whether each resource block in the set of frequency domain resource blocks is allocated for possible PUSCH transmission.
At step 730, a physical layer message may be received. The physical layer message may indicate a second subset of resource blocks in the set of frequency domain resource blocks for possible PUSCH transmission in the uplink subframe. In step 740, an upper layer signaling indicating the open loop power control parameters may be received.
At step 750, a subset of resource blocks may be selected from the set of frequency domain resource blocks for possible PUSCH transmission based on selection criteria. The selection criteria may use at least a resource set size obtained from the instruction, a modulo function, and an identifier associated with the UE. A subset of the selected resource blocks may be one resource block. The selection criterion may use at least one of a sub-frame number and a resource block aggregation level. For example, the resource block aggregation level may be the number of resource blocks transmitted by the UE. The UE may have a UE Cell Radio Network Temporary Identifier (C-RNTI) and may be configured to transmit a Cyclic Redundancy Code (&quot; C-RNTI &quot;) scrambled by the UE C-RNTI over a downlink (DL) control channel for the uplink sub- A subset of the resource blocks may be selected in response to failing to detect a DCI format 0/4 having a CRC. The selecting may also include selecting a cyclic shift for the demodulation reference signal (DMRS) for PUSCH transmission in the uplink sub-frame based at least on the identifier of the UE.
In step 760, the transmit power for the PUSCH transmission in the subset of resources may be determined based on the open loop power control parameters. At step 770, at least one other parameter may be determined for the PUSCH transmission. According to a possible embodiment, the cyclic shift may be determined for the DMRS for the PUSCH transmission and the scrambling initialization for the PUSCH transmission may be selected based on the cyclic shift determined for the DMRS for the PUSCH transmission in the uplink sub-frame have. According to a possible embodiment, an orthogonal cover code (OCC) sequence for the demodulation reference signal DMRS may be selected for the PUSCH transmission in the uplink subframe based at least on the identifier of the UE. According to a possible embodiment, the OCC sequence may be determined for the DMRS for PUSCH transmission and the scrambling initialization for PUSCH transmission may be selected based on the OCC sequence determined for the DMRS for the PUSCH transmission in the uplink sub-frame have.
In step 780, the PUSCH may be transmitted in a subset of the selected resource blocks in the uplink subframe. The PUSCH may be transmitted in the uplink subframe to the first subset of the selected resource blocks only if the first subset of resource blocks belongs to the second subset of resource blocks. The PUSCH may also be transmitted in a subset of selected resource blocks regardless of whether the first subset of resource blocks belongs to the second subset of resource blocks. At step 790, the flowchart 700 may be terminated.
Notwithstanding the specific steps shown in the Figures, various additional or different steps may be performed according to the embodiment, and depending on the embodiment, one or more of the specific steps may be rearranged, repeated, . In addition, some of the steps performed may continue at the same time or be repeated continuously while the other steps are being performed. Furthermore, different steps may be performed by different elements or in a single element of the disclosed embodiments.
8 is an exemplary block diagram of an apparatus 800, such as a wireless communication device 110, in accordance with a possible embodiment. The apparatus 800 includes a housing 810, a controller 820 in the housing 810, an audio input and output circuit 830 connected to the controller 820, a display 840 connected to the controller 820, a controller 820, An antenna 855 connected to the transceiver 850, a user interface 860 connected to the controller 820, a memory 870 connected to the controller 820 and a network interface 820 connected to the controller 820. [ 880 &lt; / RTI &gt; Apparatus 800 may perform the methods described in all embodiments.
Display 840 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 850 may comprise a transmitter and / or a receiver. Audio input and output circuitry 830 may include a microphone, a speaker, a converter, or any other audio input and output circuitry. The user interface 860 may include a keypad, keyboard, buttons, touchpad, joystick, touch screen display, other additional display, or any other device useful for providing an interface between a user and an electronic device. The network interface 880 may connect a universal serial bus port, an Ethernet port, an infrared transmitter / receiver, a USB port, an IEEE 1398 port, a WLAN transceiver, or a device to a network, device or computer, Lt; RTI ID = 0.0 &gt; and / or &lt; / RTI &gt; The memory 870 may include a random access memory, a read only memory, an optical memory, a flash memory, a removable memory, a hard drive, a cache, or any other memory that may be coupled to the wireless communication device.
The device 800 or controller 820 may implement any operating system, such as Microsoft Windows®, UNIX® or LINUX®, Android ™, or any other operating system. Device operating software may be written in any programming language, such as, for example, C, C ++, Java, or Visual Basic. The device software may also be run on an application framework, such as, for example, a Java 占 framework, a .NET 占 framework, or any other application framework. The software and / or operating system may be stored in memory 870 or elsewhere on the device 800. [ The device 800 or controller 820 may also implement the disclosed operations using hardware. For example, the controller 820 may be any programmable processor. It should also be noted that the disclosed embodiments may be implemented in a general or special purpose computer, a programmed microprocessor or microprocessor, peripheral integrated circuit elements, application specific integrated circuits or other integrated circuits, hardware / electronic logic circuits such as discrete element circuits, Programmable logic devices such as arrays, field programmable gate arrays, and the like. In general, the controller 820 may be any controller or processor device or devices capable of operating the wireless communication device and implementing the disclosed embodiments.
According to a possible embodiment, the controller 820 may obtain configuration information regarding a downlink control information (DCI) message for physical uplink shared channel (PUSCH) transmission. The transceiver 850 may receive the DCI message on the physical downlink control channel (PDCCH) in the first subframe. The DCI message may indicate a plurality of resource assignments in the second subframe for the uplink carrier, from which the UE may select one resource allocation for transmission on the uplink carrier. The DCI message may be a cyclic redundancy check (CRC) scrambled by a radio network temporary identifier (RNTI) that may be indicated via higher layers that are higher than the physical layer. Each resource allocation of a plurality of resource allocations may have the same number of resource blocks. The controller 820 may select a resource allocation from a plurality of resource assignments using a selection criterion. The device 800 may have a UE identifier, and the selection criteria may be based on a hashing function based at least on the UE identifier, or may be based on any other useful selection criteria. The device 800 may have a cell radio network temporary identifier (C-RNTI) and the controller 820 may determine a parameter for a demodulation reference signal (DMRS) for transmission of a data packet based on the C-RNTI . The device 800 may also have a cell radio network temporary identifier (C-RNTI) and a contention-based cell radio network temporary identifier (CB C-RNTI) configured via higher layers, Can be scrambled. The controller 820 may also determine parameters for the DMRS for transmission based on the at least one field indicated in the DCI message. For example, the parameters may include cyclic shifts, orthogonal cover code (OCC) sequences, or other parameters for the DMRS for transmission. Transceiver 850 may transmit a data packet on the PUSCH in the resource of the selected resource allocation in the second subframe for the uplink carrier.
According to another possible embodiment, the controller 820 may obtain configuration information regarding a downlink control information (DCI) message for physical uplink shared channel (PUSCH) transmission. The transceiver 850 may receive the DCI message in the first subframe. The DCI message may indicate a resource allocation and modulation and coding scheme. The DCI message may indicate a plurality of cyclic shifts from which the UE may select one circular shift for transmission in the second sub-frame for the uplink carrier. The number of cyclic shifts in the plurality of cyclic shifts indicated in the DCI message may be 2 or any other useful number. For example, the first cyclic shift may be indicated using the cyclic shift and the OCC index field for the demodulation reference signal DMRS of the DCI message. The second cyclic shift may be indicated using a field used for transmit power control (TPC) for the physical uplink shared channel (PUSCH) and a field used for the new data indicator (NDI). The DCI message may implicitly or explicitly indicate the number of cyclic shifts in the plurality of cyclic shifts from which the UE may select a cyclic shift from it for transmission. The controller 820 may select a cyclic shift from a plurality of indicated cyclic shifts based on the selection criteria. The controller 820 may also select scrambling initialization for PUSCH transmission based on at least a cyclic shift selected for the DMRS. The transceiver 850 may transmit the data packet on the PUSCH in the resource indicated by the resource allocation and modulation and coding scheme, using the DMRS based on the cyclic shift selected in the second subframe for the uplink carrier.
According to a possible implementation, the transceiver 850 may receive the DCI message on the physical downlink control channel (PDCCH) in the first subframe. The DCI message may indicate a resource allocation and modulation and coding scheme and may indicate a plurality of cyclic shifts in which the UE may select one cyclic shift from it for transmission. The DCI message may be a cyclic redundancy check (CRC) scrambled by a radio network temporary identifier (RNTI) indicated via higher layers that are higher than the physical layer.
According to another possible implementation, the indication for a plurality of cyclic shifts may comprise a plurality of cyclic shifts and an indication for orthogonal cover code (OCC) sequence pairs. The controller 820 may select a cyclic shift and OCC sequence pair from a plurality of indicated cyclic shift and OCC sequence pairs based on the selection criteria. The transceiver 850 may transmit the data packet over the PUSCH using the DMRS based on the selected cyclic shift and OCC sequence pair.
According to another possible embodiment, the controller 820 may obtain an indication indicating a set of frequency domain resource blocks for possible PUSCH transmission in an uplink subframe. The indication may be a bitmap indication indicating whether each resource block in the set of frequency domain resource blocks is allocated for possible PUSCH transmission. The indication may also be any other indication.
Controller 820 may select a subset of resource blocks from the set of frequency domain resource blocks for possible PUSCH transmission based on selection criteria. The selection criteria may use at least a resource set size obtained from the instruction, a modulo function, and an identifier associated with the device 800. The selection criteria may also use one or more of a sub-frame number and a resource block aggregation level. Transceiver 850 may transmit the PUSCH in a subset of the selected resource blocks in the uplink subframe.
According to a possible implementation, the subset of resource blocks may be the first subset of resource blocks. The indication may be an upper layer message from a layer higher than the physical layer. Transceiver 850 may receive physical layer messages. The physical layer message may indicate a second subset of resource blocks in the set of frequency domain resource blocks for possible PUSCH transmission in the uplink subframe. The transceiver 850 may transmit the PUSCH to the first subset of the selected resource blocks in the uplink subframe only if the first subset of resource blocks belongs to the second subset of resource blocks.
According to another possible implementation, the transceiver 850 may receive higher layer signaling indicating the open loop power control parameters. Controller 820 may determine transmit power for PUSCH transmission in a subset of resources based on open loop power control parameters. The controller 820 may also select a parameter for the demodulation reference signal DMRS for PUSCH transmission in the uplink subframe based at least on the identifier of the device 800. [ The controller 820 may further determine a parameter for the DMRS for PUSCH transmission and may select scrambling initialization for PUSCH transmission based at least on parameters determined for the DMRS for PUSCH transmission in the uplink subframe . The determined parameter may be a cyclic shift, OCC, or any other parameter useful for the DMRS for PUSCH transmission in the uplink subframe.
The method of the present disclosure may be implemented on a programmed processor. However, the controllers, flowcharts, and modules may also be implemented in a general purpose or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an integrated circuit, a hardware electronic or logic circuit, such as discrete element circuitry, Lt; / RTI &gt; In general, any device in which a finite state machine that can implement the flowcharts shown in the figures resides may be used to implement the processor functions of the present disclosure.
While this disclosure has been described using specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those of ordinary skill in the art. For example, in various embodiments, various components of the embodiments may be interchanged, added, or replaced. Furthermore, not all elements of each figure are required for operation of the disclosed embodiments. For example, one of ordinary skill in the art of the disclosed embodiments will be able to make and use the teachings of this disclosure by simply using the elements of the independent claims. Accordingly, the embodiments of the disclosure set forth herein are intended to be illustrative, not limiting. Various modifications may be made without departing from the spirit and scope of the disclosure.
In this document, relational terms such as "first "," second ", etc. may be used only to distinguish one entity or action from another entity or action and any such actual relationship There is no need to ask for or suggest an order. The phrase "at least one of" listed after the list is defined to mean one, some or all, without necessarily having to mean all of the elements of the list. The terms " comprises, "" comprising," or any other modified term thereof, are intended to encompass a non-exclusive inclusion relationship, Or apparatus may include other elements not expressly listed or inherent to such process, method, article of manufacture, or apparatus, but rather may include only those elements. Elements of a singular representation (such as "a", "an", etc.) do not exclude the presence of additional identical elements in a process, method, article of manufacture, or apparatus that includes the element, without additional constraints. Also, the term "another" is defined as at least a second or more. The terms "including" and "having" as used herein are defined as "comprising". Further, the background part is created by the inventor's own understanding of the context of some embodiments at the time of filing, and is not limited to any problems in existing technologies and / or problems encountered when the inventor himself / .
A method in a user equipment,
Acquiring configuration information on a downlink control information message for physical uplink shared channel transmission;
Receiving the downlink control information message on a physical downlink control channel in a first subframe, the downlink control information message comprising the step of the user equipment selecting a resource allocation therefrom for transmission on an uplink carrier Wherein the downlink control information message indicates a plurality of resource assignments in a second subframe for the uplink carrier, the downlink control information message indicating a cyclic scrambled by a wireless network temporary identifier indicated via higher layers A cyclic redundancy check;
Selecting a resource allocation from the plurality of resource allocations using a selection criterion, the selection criterion being based on at least one parameter measured by the user equipment; And
Transmitting a data packet on the physical uplink shared channel in the resource of the selected resource allocation in the second subframe for the uplink carrier
2. The method of claim 1, wherein each resource allocation of the plurality of resource assignments has the same number of resource blocks.
Wherein the user equipment has a cell wireless network temporary identifier,
The method further comprises determining a cyclic shift for a demodulation reference signal for transmission of the data packet based on the cell radio network temporary identifier.
2. The method of claim 1, further comprising: determining a cyclic shift for a demodulation reference signal for the transmission based on at least one field indicated in the downlink control information message.
The method further comprises determining an orthogonal cover code sequence for a demodulation reference signal for transmission of the data packet based on the cell radio network temporary identifier.
The method of claim 1, further comprising: determining an orthogonal cover code sequence for a demodulation reference signal for the transmission based on at least one field indicated in the downlink control information message .
2. The method of claim 1, wherein the number of resource assignments is explicitly indicated in the downlink control information message.
2. The method of claim 1, wherein the number of resource assignments is implicitly indicated in the downlink control information message.
2. The method of claim 1, wherein the user equipment has a cell radio network temporary identifier and a contention-based cell radio network temporary identifier configured via higher layers, and the downlink control information is determined by the contention-based cell radio network temporary identifier / RTI &gt;
Determining a cyclic shift for a demodulation reference signal for the transmission; And
Selecting scrambling initialization for physical uplink shared channel transmission based at least on the cyclic shift determined for the demodulation reference signal for the transmission
Determining an orthogonal cover code sequence for the demodulation reference signal for the transmission; And
Selecting scrambling initialization for physical uplink shared channel transmission based at least on the orthogonal cover code sequence determined for the demodulation reference signal for the transmission
A controller configured to obtain configuration information regarding a downlink control information message for physical uplink shared channel transmission; And
A transceiver configured to receive the downlink control information message on a physical downlink control channel in a first subframe, the downlink control information message including information indicating that the device has allocated one resource from it for transmission on an uplink carrier , The downlink control information message indicating a plurality of resource assignments in a second sub-frame for the uplink carrier, the downlink control information message indicating that the downlink control information message has been scrambled by a wireless network temporary identifier indicated via upper layers that are higher than the physical layer Cyclic redundancy check -
Wherein the controller is configured to select a resource allocation from the plurality of resource allocations using a selection criterion, the selection criterion being based on at least one parameter measured by the device,
Wherein the transceiver is configured to transmit a data packet over the physical uplink shared channel at a resource of a resource allocation selected in the second subframe for the uplink carrier.
16. The apparatus of claim 15, wherein each resource allocation of the plurality of resource assignments has the same number of resource blocks.
The device having a cell wireless network temporary identifier,
Wherein the controller is further configured to determine a parameter for a demodulation reference signal for transmission of the data packet based on the cell radio network temporary identifier.
16. The apparatus of claim 15, wherein the controller is further configured to determine a parameter for a demodulation reference signal for the transmission based on at least one field indicated in the downlink control information message.
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KR1020197020568A KR20190088569A (en) 2015-07-14 2016-06-02 Method and apparatus for reducing latency of lte uplink transmissions
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