Method and apparatus for reducing latency of lte uplink transmissions

Abstract

This invention relates to a method and apparatus for reducing latency in LTE uplink transmission. A method and apparatus for reducing latency in LTE uplink transmission are provided. Configuration information regarding a DCI message for PUSCH transmission can be transmitted on the PDCCH in a first subframe. The DCI message can indicate multiple resource allocations for an uplink carrier in a second subframe, from which the UE can select one for transmission on the uplink carrier. The DCI message can be scrambled with a CRC scrambled by an RNTI indicated by a higher layer than the physical layer. A selection criterion can be used to select a resource allocation from the multiple resource allocations. Data packets in the resources of the selected resource allocation in the second subframe on the uplink carrier can be received from the UE on the PUSCH.

Description

[0001] This application is a divisional application of PCT application number PCT / US2016 / 035552, which entered the Chinese national phase on January 12, 2018, with an international filing date of June 2, 2016, Chinese application number 201680041277.6, and entitled "Method and apparatus for reducing latency of LTE uplink transmission".

[0002] Cross-references to related applications

[0003] This application relates to a method and apparatus for reducing uplink transmission latency in LTE, Motorola Mobility filing number MM01559, and a method and apparatus for reducing uplink transmission latency in LTE, Motorola Mobility filing number MM01560, both of which were filed on the same date as this application and jointly designate the assignee of this application, and are incorporated herein by reference. Technical Field

[0004] This disclosure relates to a method and apparatus for reducing latency in LTE uplink transmissions. More specifically, this disclosure relates to resource selection for reducing LTE uplink transmission latency. Background Technology

[0005] Currently, wireless communication devices such as smartphones, cellular phones, tablets, personal computers, and other devices communicate using wireless signals through networks such as Long Term Evolution (LTE) cellular networks. Many communications are sensitive to latency, such as communication delays, which slow down data transmission. Unfortunately, current systems suffer from latency due to the negotiation that communication devices must perform with base stations to transmit data. For example, in order to transmit data, a device must first request authorization from the base station to transmit the data, and then wait for authorization before transmitting the data. This results in undesirable latency that delays communication between the communication device and the network.

[0006] Therefore, there is a need for methods and devices for reducing LTE uplink transmission latency. Summary of the Invention

[0007] This invention relates to a method in a user equipment, the method comprising: acquiring configuration information regarding a downlink control information message for transmission on a physical uplink shared channel; receiving the downlink control information message on a physical downlink control channel in a first subframe, the downlink control information message indicating multiple resource allocations for an uplink carrier in a second subframe, the user equipment selecting one of the multiple resource allocations for transmission on the uplink, wherein the downlink control information message is scrambled with a cyclic redundancy check via a radio network temporary identifier indicated by a higher layer than the physical layer; selecting a resource allocation from the multiple resource allocations using a selection criterion based on at least one parameter measured by the user equipment; and transmitting data packets on the physical uplink shared channel on the uplink carrier in the resources of the selected resource allocation in the second subframe. Attached Figure Description

[0008] To describe the ways in which the advantages and features of this disclosure can be obtained, a description of this disclosure is presented with reference to specific embodiments illustrated in the accompanying drawings. These drawings depict only exemplary embodiments of this disclosure and are therefore not to be considered as limiting its scope.

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

[0010] Figure 2 This is an example signal flow diagram illustrating the signals required for transmitting uplink packets using the current LTE uplink mechanism between a wireless communication device and a base station.

[0011] Figure 3 This is an example 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.

[0012] Figure 4 This is an example flowchart illustrating the operation of a user equipment for a basic contention-based resource selection scheme according to possible embodiments;

[0013] Figure 5 This is an example flowchart illustrating the operation of a wireless communication device according to a possible embodiment;

[0014] Figure 6 This is an example flowchart illustrating the operation of a wireless communication device according to a possible embodiment;

[0015] Figure 7 This is an example flowchart illustrating the operation of a wireless communication device according to a possible embodiment;

[0016] Figure 8 This is an example block diagram of a device according to a possible embodiment. Detailed Implementation

[0017] The embodiments provide a method and apparatus for reducing latency in LTE uplink transmission.

[0018] According to possible embodiments, configuration information regarding downlink control information (DCI) messages for Physical Uplink Shared Channel (PUSCH) transmission can be obtained. The DCI message can be received on the Physical Downlink Control Channel (PDCCH) in the first subframe. The PDCCH can be a cell-specific reference signal demodulated PDCCH, an enhanced PDCCH based on a dedicated reference signal demodulated (EPDCCH), a further enhanced physical downlink control channel, or a combination thereof. The DCI message can indicate multiple resource allocations for the uplink carrier in the second subframe, from which the user equipment (UE) can select one for transmission on the uplink carrier. The DCI message can be scrambled with a Cyclic Redundancy Check (CRC) scrambled via a Radio Network Temporary Identifier (RNTI) indicated by a higher layer than the physical layer. A selection criterion can be used to select a resource allocation from the multiple resource allocations. Data packets can be transmitted on the PUSCH of the selected resource allocation in the second subframe on the uplink carrier.

[0019] According to a possible embodiment, a DCI message can be received in the first subframe. The DCI message can indicate resource allocation and modulation and coding schemes, and can indicate to the UE from which to select one of a plurality of cyclic shifts for transmission in a second subframe for the uplink carrier. A cyclic shift can be selected from the plurality of indicated cyclic shifts based on a selection criterion. Data packets can be transmitted on the PUSCH in the resources indicated by the resource allocation and modulation and coding schemes and using a demodulation reference signal (DMRS) based on the selected cyclic shift in the second subframe on the uplink carrier.

[0020] According to a possible embodiment, an indication can be obtained, wherein the indication can specify a set of frequency domain resource blocks for possible PUSCH transmissions in an uplink subframe. A subset of resource blocks for possible PUSCH transmissions can be selected from this set of frequency domain resource blocks based on selection criteria. The selection criteria can use at least the resource set size obtained from the indication, can use a modulo function, and can use an identifier associated with the UE, wherein the modulo function can be represented as "mod(a,b)" or "a mod b", representing the remainder after a is divided by b. The PUSCH can be transmitted in an uplink subframe with the selected subset of resource blocks. The duration (or transmission time interval or subframe duration) of the PUSCH used for latency reduction can be defined as a Rel-8 TTI size similar to 1 millisecond, or it can be shorter, such as half a millisecond, and this can be configured by the network based on the desired latency reduction target or application. In another example, the frequency domain resource blocks for potential PUSCH transmissions used to reduce latency can be defined as the same as in Rel-8 LTE, or they can be defined to correspond to short transmission intervals such as 0.5ms instead of 1ms. In a further example, the set of resource blocks available for potential PUSCH transmissions can be configured only in a subset of the possible uplink subframes. For example, the set of resource blocks can be obtained in each alternating subframe, where RB0-RB6 can be used for potential PUSCH transmissions in subframes indexed 0, 2, 4, etc., and each RB can have a duration of 1 millisecond.

[0021] Figure 1 This is an example block diagram of system 100 according to a possible embodiment. System 100 may include a wireless communication device 110 such as a UE, a base station 120 such as an enhanced Node B (eNB), and a network 130. The wireless communication device 110 may be a wireless terminal capable of transmitting and receiving communication signals on a wireless network, a portable wireless communication device, a smartphone, a cellular phone, a flip phone, a personal digital assistant, a device with a subscriber identity module, a personal computer, a selective call receiver, a tablet computer, a laptop computer, or any other device.

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

[0023] According to the LTE standard, uplink communication from the UE to the eNB uses single-carrier FDM(A) (SC-FDMA) or DFT-spread OFDM(A) (DFT-SOFDM(A)). In SC-FDM or DFT-SOFDM, block transmission of QAM data symbols can be performed by: first Discrete Fourier Transform (DFT) spreading (or precoding), followed by subcarrier mapping and OFDM modulation using a conventional OFDM modulator. Using DFT precoding allows for a moderate cubic metric / peak-to-average power ratio (PAPR), which can lead to reduced cost, size, and power consumption of the UE power amplifier. According to DFT-SOFDM, each subcarrier used for uplink transmission can include information for the modulated signal used for all transmissions, with the input data stream spread on each subcarrier. Uplink data can be transmitted using PUSCH. Although the embodiments describe uplink packet transmission based on the LTE standard, it is noted that the same techniques can be applied to uplink transmissions based on other modulation schemes such as conventional OFDM and other transmission schemes.

[0024] The embodiments can provide resource allocation and selection aspects for reducing latency in LTE uplink transmissions. Reducing latency for user data packets can provide a better user experience, such as reduced buffering requirements and other reductions in complexity, as well as improved performance such as faster link adaptability / feedback, improved TCP performance, and other performance improvements. It also supports new applications that may be latency-critical, such as augmented reality applications, vehicular communication applications, and other applications.

[0025] For a UE in Radio Resource Control (RRC_CONNECTED) state, the UE is typically able to search for downlink grants in each downlink subframe, which lasts for one millisecond. If the eNB receives a packet to be sent to the UE, it can immediately transmit the packet to the UE in the next downlink subframe using control and data channels (such as PDCCH or EPDCCH) and the Physical Downlink Shared Channel (PDSCH).

[0026] Figure 2The diagram illustrates an example signaling flow diagram of the signals required for transmitting uplink packets using the current LTE uplink mechanism between a wireless communication device 110, such as a UE, and a base station 120, such as an eNB. For uplink packet transmission, if at 210 the uplink buffer of device 110 is empty and device 110 receives an uplink packet in its buffer, typically first at 220, device 110 must send a scheduling request (SR) to base station 120, then at 230, base station 120 sends an uplink grant to device 110, and then device 110 transmits the packet at 240 on the resource indicated by base station 120. Each of these three steps adds to the total delay that uplink packet transmission can experience. Typically, SR resources are dedicated resources for the UE and are configured with a specific periodicity such as every 5ms / 2ms / 10ms. By providing SR opportunities to UEs on a more frequent basis, such as by configuring a 2ms periodicity for all UEs, it is possible to reduce the latency used for SR transmission, but this may result in a significant increase in uplink overhead.

[0027] Figure 3 This is an example signal flow diagram illustrating, according to a possible embodiment, the signals associated with uplink packet transmission using a contention-based uplink (CB-UL) mechanism between a wireless communication device 110, such as a UE, and a base station 120, such as an eNB. At 310, the base station 120 is able to send a contention-based uplink grant to the device 110, such as via broadcast or other messages. At 320, the device 110 is able to have an uplink packet ready to be transmitted. At 330, the device 110 is able to send the uplink packet to the base station 120 using information from the uplink grant. For example, embodiments can avoid delays due to SRs used for some uplink transmissions. This can be accomplished by scheduling the CB-UL. In this case, the eNB can send an uplink grant in its cell, and any UE can use that grant to prepare and transmit its uplink packets. The UE can embed specific information such as a Media Access Control Identifier (MAC ID), a Cell Radio Network Temporary Identifier (C-RNTI), and other information in the packet, so the eNB can determine which UE is sending the packet. In another example, a group of UEs configured by UL authorization for CB-UL and addressed via group-based contention-based RNTI CB-RNTI can use specific resource allocations in the UL authorization.

[0028] Contention-based uplink grants can be transmitted using DCI formats 0 / 1A and / or 1C, which support a more compact payload size compared to some other DCI formats. Grants can be transmitted in any search space, such as the Common Search Space (CSS) or the UE-Specific Search Space (UESS). In some cases, the CB-UL-Downlink Control Information (CB-UL-DCI) format is aligned with the size of an existing DCI format searched by the UE. If the CB-UL-DCI format size is not aligned with an existing DCI format size, additional blind decoding can also be supported by the UE. For example, four additional blind decodings can be supported in the Common Search Space to support CB-UL-DCI. A specific RNTI (such as CB-RNTI) configured via higher layers can be used to distinguish the CB-UL-DCI format from other formats. Alternatively, explicit fields can be included in DCI 0 / 1A and / or 1C to distinguish the CB-UL grant from other grants carried in the DCI format.

[0029] For the Enhanced Physical Downlink Control Channel (EPDCCH) UESS, the UESS can be overlapped for a group of UEs. Therefore, it is possible to send CB uplink grants within a UE-specific search space. Then, the CB uplink DCI format payload size can be aligned with the UE's DCI format 0 / 1A / payload size in the UESS.

[0030] According to a possible embodiment, the UE can transmit packets with low latency. To transmit packets, the UE can indicate to the network its interest in and / or ability to support uplink latency reduction, and the UE can obtain configuration information regarding DCI messages used for Physical Uplink Shared Channel (PUSCH) transmission. The base station can indicate its ability to support uplink latency reduction via a system information broadcast message or by using reserved fields in a master information block or dedicated message. Upon receiving this indication, the UE can further indicate to the network that it also supports low latency. The base station can then send configuration information to the UE via a system information broadcast message or dedicated message. Alternatively, if a group of UEs camped on the cell has the capability to support latency reduction, the network can implicitly or explicitly authorize the group of UEs camped on the cell to operate in CB mode. The network can know this capability via UE category / capability information. The UE can be in a Radio Resource Control Connected (RRC_Connected) state and can perform Radio Resource Management (RRM) measurements, such as path loss estimation and other measurements, and can adjust uplink timing alignment based on network commands such as Timing Advance (TA) commands, and based on the UE's own downlink receive timing, such as adjusting to maintain uplink timing alignment when the timing alignment timer does not expire. The UE can then obtain information indicating one or more sets of resources for possible contention-based (CB) PUSCH transmissions, such as via Media Access Control (MAC), RRC, or other information sources. The UE can also obtain information such as the set of open-loop power control parameters (P0, α, etc.), the set of modulation and coding scheme parameters, redundancy versions, other information for, for example, virtual cell identifiers for reference signal generation, and other information also related to the transmission of CB PUSCH transmissions. When the UE has data in its UL buffer and wants to transmit data with low latency, the UE can search the downlink control area to detect uplink grants intended for the UE, such as from the first DCI message via DCI format 0 / 4 with a CRC scrambled with the UE's C-RNTI. Contention-based PUSCH transmissions can be configured only on the primary cell or on a subset of cells configured for the UE.

[0031] If the UE does not detect a DCI intended for use by the UE, the UE can detect a second DCI message using a second RNTI. For example, the UE can receive the second DCI message on the Physical Downlink Control Channel (PDCCH) in the first subframe. The second DCI message can indicate multiple resource allocations for the first carrier in the second subframe, from which the UE selects one for transmission on the first carrier. The second DCI message can be scrambled with a Cyclic Redundancy Check (CRC) scrambled via a Radio Network Temporary Identifier (RNTI) indicated by a higher layer than the physical layer. For example, the second DCI message can indicate multiple resource allocations that are subsets of resource allocations indicated by information obtained via MAC, RRC, and / or another DCI message. The UE can then use a selection method to select a subset of UL resources from the set of possible CB transmission resources in UL subframe n+k, where k can be fixed, such as 4 in Frequency Division Duplex (FDD), and k can be variable, such as based on the TDD uplink / downlink (UL / DL) configuration in Time Division Duplex (TDD). The selection method can include the UE selecting one or more of the following: a number of resource blocks (RBs), an MCS index, a transport block size, a demodulation reference signal (DMRS) cyclic shift, and a DMRS orthogonal cover code (OCC) sequence. The UE can then transmit the PUSCH to send UL data using the selected UL resources and associated parameters such as modulation and coding schemes, power control settings, and other parameters. The UE can also embed its identifier, such as a UE identifier (UE ID) or C-RNTI, or other UE identifiers, which the eNB can use to detect which UE transmitted the associated PUSCH. The UE can also include a buffer status report in the associated PUSCH. If the eNB successfully detects the PUSCH, it can acknowledge packet reception by sending feedback to the UE via a Physical Hybrid Automatic Repeat Request (ARQ) indicator channel (PHICH) or by sending an explicit downlink message addressed to the UE. The UE can then clear the contents of the UL buffer. PUSCHs transmitted based on contention-based resources can also be represented as low-latency PUSCHs.

[0032] Implementations can provide multiple resource allocations within a single grant. For example, the common search space, such as on the PDCCH, may be overloaded and only a limited number of transmission opportunities can be provided, where only 4 grants can be sent and the common search space (CSS) capacity is 16 CCE. Therefore, for CB uplink, a single CB-based grant can schedule uplinks on multiple uplink resources in a given subframe. When additional blind decoding is allowed to accommodate CB uplink transmissions, an extended common search space can be defined using a System Information Radio Network Temporary Identifier (SI-RNTI) or a CB-RNTI with more candidates for aggregation levels 4 or 8 and / or additional candidates for aggregation levels 1 and 2. New common search spaces with different aggregation levels (e.g., 2, 4, 8, 16) can be defined for the EPDCCH.

[0033] A first example of a CB authorization field indicating multiple resource allocations can include a 0 / 1A distinction field. The CB authorization field can include fields for the first resource allocation, including a frequency hopping flag, an RB allocation field, an MCS, a TPC for PUSCH, and a circular shift for DMRS and OCC indexes. The CB authorization field can also include fields for the second resource allocation, including a frequency hopping flag, an RB allocation, an MCS, a TPC for PUSCH, and a circular shift for DMRS and OCC indexes. The CB authorization field can also include a resource allocation (RA) type. These fields can be part of a DCI message. To maintain a consistent DCI message size, fields in the current DCI message that are not useful for CB authorization can be replaced with additional CB authorization fields. Table 1 illustrates example fields and descriptions for DCI format 1A. Example fields that can be replaced with CB authorization fields include the NDI field, the TPC for the PUSCH field, the circular shift for the DMRS and OCC index fields, the CSI request field, and other fields. Table 1 also illustrates example fields and descriptions of DCI format 1C, where the number of bits in 1C can be 12 bits (5MHz), 13 bits (10MHz), 15 bits (20MHz), or any other useful number of bits.

[0034] Table 1. Fields and descriptions for DCI format 0 and 1C

[0035]

[0036] In the second example, one or more grants can be jointly encoded to reduce load or adapt the grants to an existing UL DCI load. In this example, the CB grant field can include a 0 / 1A distinction field. The CB grant field can also include fields for the first and second resource allocations, including fields interpreting the joint allocation, a joint frequency hopping flag, a joint RB allocation field, a joint MCS, joint transmit power control (TPC) for PUSCH, and a joint cyclic shift for DMRS and OCC index selection. The CB grant field can also include an RA type.

[0037] To illustrate the example, a field can be included to interpret the joint allocation. A field set to 0 indicates the absence of a second resource allocation. A field set to 1 suggests the presence of 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 could be the next two resource blocks, RB2 and RB3. The joint MCS field can indicate that a single MCS is used for both resource allocations. The UE receiving this uplink grant can select one of the resource allocations based on random selection or using a set of predetermined rules. For example, if the number of RBs used for each resource allocation is different, the UE can select the resource allocation based on its uplink buffer state. The UE can also select the resource allocation based on a path loss threshold. This threshold can be configured via higher-layer signaling.

[0038] The implementation provides the UE with the ability to autonomously select from contention-based resource areas. For example, to reduce latency for uplink packets, the eNB can configure a set of resource blocks or frequency areas in the uplink system bandwidth, such as via higher layers. These resources, including Buffer Status Reports (BSRs), can be used by any UE or group of UEs for uplink transmission. These resources can be advertised in the SIB, in RRC messages, and / or in any other useful messages, and can be used by the UE at any time when it wants to transmit packets with low latency, without waiting for the SR to be sent, or in other useful situations. For example, the UE can obtain from the eNB an indication of a set of frequency domain resource blocks for possible PUSCH transmissions in uplink subframes.

[0039] The configured resources can be implicitly indicated. For example, resources for device-to-device (D2D) or sidelink operations can also be used to indicate resources to be used for advertised uplink resources. For Enhanced Interference Suppression and Service Adaptation (EIMTA) under TDD, the set of uplink resources for the CB uplink can be limited to the uplink subframes indicated by the TDD configuration corresponding to the DL reference UL / DL configuration. In another option, the set of UL resources to be used for the CB uplink can be determined using a dynamic UL / DL configuration indicated by a dynamic UL / DL configuration with a CRC scrambled by EIMTA-RNTI, indicated in DCI format 1C. In another example, resources can be indicated by RACH resources / configuration. Since RACH resources are allocated by the cell to serve UEs camped on that cell, the number of UEs attached to that cell can be implicitly taken into account. Therefore, this information can be used to allocate the number of CB-UL resources. For example, CB-UL resources can be determined based on a formula that takes into account the RACH configuration.

[0040] As another example, a subset of RACH resources can be reused as CB-UL resources. In a simple example, all RACH resources can be reused as CB-UL resources. For example, RACH configuration index 45 could have 6 RB resources available per odd-numbered subframe that can be reused for CB UL transmission. In this particular example, additional signaling to inform the UE about CB-UL resources may not be required. This approach might require additional detection processing at the eNB side.

[0041] The eNB can configure, for example via higher layers, a set of modulation and coding schemes (MCS) and / or transport block sizes that the UE can use to transmit uplink packets in configured resources. Alternatively, for example, if a contention-based uplink is used to transmit BSR or other fixed-size payloads, this configuration can be fixed in the specification. The MCS and / or TBS can also depend on other parameters, such as the channel quality of the link between the UE and the eNB, such as in TDD operation where reciprocity can be assumed. The eNB can also configure, for example via higher layers, any set of cyclic shift and / or overlay code sequences that the UE can use to transmit DMRS along with uplink packets in configured resources.

[0042] The eNB can additionally configure a set of PHICH resources, such as via higher layers, for sending ACK / NACK feedback information associated with uplink transmissions in the configured resources. The UE can use this information to receive feedback regarding its uplink transmissions in the configured resources. The eNB can also further configure, such as via higher layers, a separate set of power control settings parameters, such as P0 and α, and other power control settings for uplink transmissions in the configured resources by the UE. The eNB can also dynamically control the use of uplink resources configured by higher layers via physical layer and / or MAC layer signaling.

[0043] According to the first implementation, the eNB can configure a set of resource blocks (e.g., RB0, RB1, RB2, RB4) for a contention-based uplink, and the eNB can expect the UE to select a resource block and transmit on that resource block. The UE can select the resource block based on a hash function, which can be based on the UE's C-RNTI, subframe number, system frame number, set configuration index, UE-eNB link quality, determined cyclic shift (CS) and orthogonal overlay code (OCC) index, and other useful information. For example, the UE can select one RB from the set of RBs indexed by (L*M+C-RNTI+SFN)mod N_RBs, where L is selected from {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 coprime numbers.

[0044] According to the second implementation, the eNB can configure a set of starting resource blocks (e.g., RB0, RB1, RB2, RB4) for contention-based uplinks, and the UE can transmit on L consecutive resources at one of the allowed starting resource blocks from this set. The allowed value of L can be pre-configured or signaled via higher layers, and the UE can select a specific value of L based on the packet or transport block (TB) it is attempting to transmit to the eNB. For example, if the UE wants to transmit a 15-byte transport block, with a 24-bit CRC, the number of information bits can be 15*8+24=144 bits, and for 1 RB (14×14=144RE), QPSK modulation can correspond to a coding rate of 1 / 2. If the UE has a 33-byte packet size, it can choose to use a 2-RB allocation to transmit the TB, achieving the same coding rate of 1 / 2. The UE can use a first orthogonal coverage code (OCC) for the 1-RB allocation and a second orthogonal coverage code for the 2-RB allocation. The CS used by the UE for 1-RB and 2-RB allocation can be the same or different.

[0045] According to the third implementation, the eNB can configure a set of resource blocks (e.g., RB0, RB1, RB2, RB4), a set of resource allocations (e.g., 1, 2, 4 RB allocations), a set of MCSs (QPSK rate 1 / 2, QPSK, rate 3 / 4, 16QAM rate 1 / 2, etc.), a set of transport block sizes (TBS) (6-bit TCP-ACK with additional L2 / L3 headers, 320-bit VoIP packets, etc.), a set of cyclic shifts (from a subset of the allowed set), and / or other configurations for contention-based uplinks. The UE can select from the set of allowed combinations based on its requirements (such as the amount of uplink data to be transmitted) and can use at least a hash function based on the UE's C-RNTI, subframe number, system frame number, configured configuration index, and / or other information.

[0046] According to the fourth implementation, the eNB can configure multiple sets of contention-based uplink resources. Each set has one of the starting resource blocks (e.g., RB0, RB1, RB2, RB4), and sets of resource allocations (e.g., 1, 2, 4 RB allocations), sets of MCSs (QPSK rate 1 / 2, QPSK, rate 3 / 4, 16QAM rate 1 / 2, etc.), sets of TBSs (6-bit TCP-ACK with additional L2 / L3 headers, 320-bit VoIP packets, etc.), sets of cyclic shifts (from subsets of the allowed sets), and / or other configurations. The UE can select one set from multiple sets based on its requirements (such as the amount of uplink data to be transmitted) and can use resources at least based on a hash function based on the UE's C-RNTI, subframe number, system frame number, configured configuration index, and / or other information. Each set can be associated with a resource allocation. For example, the first set can have only a 1 RB allocation, the second set can have only a 2 RB allocation, and so on.

[0047] The above implementation illustrates how an eNB can configure resources at a higher layer and detect uplink transmissions from UEs using these resources by blind decoding within the allowed resource set. The number of blind decodes can be limited. For example, the transmission length in an RB can be indicated to the eNB via implied / explicit indication. An example of explicit indication is that the first "m" bits of each indication, or a subset of RBs, can be assigned to represent an RB index. The RB index indicates how many RBs are used for this transmission. In another example, a subset of RBs can be used for a single RB transmission, while another subset can be used for a 2RB transmission, etc. For example, all CB-RBs can be used for a single RB transmission, while a 2RB transmission might only be allowed in specific resources, etc.

[0048] According to the fifth implementation, the eNB can configure multiple sets of contention-based uplink resources. Each set has one of the starting resource blocks (e.g., RB0, RB1, RB2, RB4), and resource allocation sets (e.g., 1, 2, 4 RB allocations), sets of MCS (QPSK rate 1 / 2, QPSK, rate 3 / 4, 16QAM rate 1 / 2, etc.), sets of TBS (6-bit TCP-ACK with additional L2 / L3 headers, 320-bit VoIP packets, etc.), sets of cyclic shifts (from subsets of allowed sets), and / or other configurations. The UE can select one set from the multiple sets based on its needs (such as the amount of uplink data to be transmitted) and / or at least based on physical layer signaling. Therefore, the eNB can control contention-based resources based on physical layer signaling. Physical layer signaling can be based on one or more fields within a common DCI transmitted on the control channel. For example, the DCI can have a one-bit indicator associated with the set, indicating whether the UE can use or not use the set in the corresponding subframe. For example, if the UE receives a DCI in downlink subframe n, the corresponding field can be applied to an uplink set in subframe n+4 or a predetermined uplink subframe (such as n+k), where k can be signaled by the eNB, or based on a set of UE capabilities indicated to the network or based on a configuration such as TDD configuration. Examples are shown in Table 2. In another example, for instance, the DCI can have a bit indicator associated with each set, indicating whether the UE can use or not use the set in the corresponding subframe.

[0049] Table 2: Uplink Type C Resource Indicator Fields

[0050]

[0051] Based on the above, 2 bits may be sufficient in the DCI format, but similar fields can also be used to control MCS indicators, TBS indicators, and other information as shown in Table 3.

[0052] Table 3: Uplink Type C Resource / MCS Indicator Fields

[0053]

[0054] According to the sixth implementation, the resource can be a small portion of the RB in the time domain. For example, the UL portion of a TDD-specific subframe can be configured as a CB resource.

[0055] The eNB can configure a set of resource blocks for a contention-based authorized area. The UE can perform a hash function to determine the starting RB and the number of RBs from that set. One of the four RRC signaling sets can be as follows:

[0056] 1. {RB3-6 (time slot 1), RB94-97 (time slot 2)}

[0057] 2. {RB13-16 (time slot 1), RB84-87 (time slot 2)}

[0058] 3. {RB23-26 (time slot 1), RB74-77 (time slot 2)}

[0059] 4. {RB33-36 (time slot 1), RB64-67 (time slot 2)}

[0060] This set can be defined to allow the UE to hop frequencies across time slots for frequency diversity. Grants can signal the allowed sets, and the UE can select resources from the allowed sets based on a hash function. Persistent resources, such as a set per subframe, can be allocated, and the sets in a given subframe can be a function indexed by the subframe. Additionally, the eNB can signal multiple sets in a subframe using dynamic signaling. A subset of the TB size and / or resource allocation size allowed for contention-based grants can be configured by the eNB. A subset of the MCS based on contention grants can be configured by the eNB. If the UE has already transmitted multiple packets in multiple subframes, e.g., in consecutive subframes, it can allow other UEs to use the resource. For example, it can perform some backoff or transmit with a lower probability than its previous attempts. The eNB can configure the probability of the UE transmitting in multiple subframes. A UE can only transmit contention-based uplink transmissions in a subframe if there is no uplink grant (such as a UE-specific grant) for transmission in the subframe.

[0061] The eNB can configure a set of resource blocks for a contention-based grant zone using methods such as bitmap indications via higher layers, where the bitmap indications can indicate whether a particular resource block belongs to a contention-based grant zone. For example, if the uplink system bandwidth corresponds to 100 resource blocks (indexed RB0, RB1, ..., RB99), a 100-bit bitmap (b0, b1, ..., b99) can be used to indicate the contention-based grant zone, and if bit b0 is set to 1, the corresponding resource block RB0 can belong to the contention-based grant zone; otherwise, RB0 may not belong to the contention-based grant zone.

[0062] In another example, the higher layer can indicate parameters that can be used to derive the corresponding bitmap, such as indicating resource block offsets and the number of resource blocks. For example, the eNB can indicate a first offset (O1) and the number of resource blocks (N1), and a second offset (O2), such that resource block RBx belongs to a contention-based region (if O1 <= x < O1 + N1, or if O2 - N1 < x <= O2). If the uplink system bandwidth corresponds to 100 resource blocks (indexed as RB0, RB1, ..., RB99), then if the higher layer indicates O1 = 10, O2 = 25, and N1 = 5, then RBx (0 <= x, 99) belongs to the contention-based grant area (if 10 <= x < 15, or if 20 < x <= 25). That is, the RBs belonging to the contention-based grant area can be given by {RB10, RB11, RB12, RB13, RB14, RB20, RB21, RB22, RB23, RB24}.

[0063] Figure 4 This is an example flowchart 400 illustrating the operation of a UE using a basic CB resource selection scheme according to a possible embodiment. At 410, the flowchart can begin. At 420, the UE can determine whether it has UL data in its buffer. If the UE has UL data in its buffer, then at 430, the UE can determine whether it has received a UL grant CRC scrambled with C-RNTI. If yes, then at 440, the UE can transmit in the resource indicated by the UL grant. If not, then at 450, the UE can determine whether there is a possible CB UL resource available in the subframe. If yes, then at 460, the UE can select a CB resource, and at 470, the UE can transmit in the selected resource. At 480, the flowchart can end.

[0064] Implementations can provide methods for resource selection, such as using hash functions to select subsets of resource blocks. For example, an uplink resource set, such as a set of frequency domain resource blocks, can include elements numbered from 0 to N. CCE，k The set of uplink resources for resource blocks of -1, where N CCE，k The total number of resources that can be configured in this set in subframe k. The set of UL resource candidates that the UE can transmit can be based on the resource space, where the resource space is at the resource aggregation level L, such as L∈{1, 2, 4, 8}. It can be limited by the set of UL resource candidates. (Related to resource space) The UL resource corresponding to UL resource candidate m can be given by the following equation:

[0065]

[0066] Where Yk As defined below, and i = 0, ..., L-1. For the common resource space, m′ = m. For the UE-specific resource space, m′ = m, where m = 0, ..., M (L) -1. M (L) This specifies the number of UL resource candidates that a UE can be allowed to transmit in a given resource space. In the first example, the UE can be allowed to select from a set of resource candidates, as shown in Example 1 of Table 4, where each resource candidate corresponds to a subset of resource blocks. In the second example, the UE can obtain resource candidates directly for transmission, as shown in Example 2 of Table 4. The RA level defining the resource space is also listed in Table 4.

[0067] Table 4: Number of candidates for resource selection

[0068]

[0069] Regarding public resource spaces, Y k It can be set to 0. In some cases, the common resource space may not be necessary, or the common resource space can be used for another purpose, such as when the UE has a fixed payload to transmit.

[0070] For UE-specific resource space at RA level L variable Y k It can be defined by the following equations

[0071] Y k =(A·Y k-1 )modD

[0072] The example value can be Y. -1 =n RNTI ≠ 0, A and D are relatively large coprime numbers, such as A = 39827 and D = 65537. And n s The number of time slots within a radio frame can be the number of time slots in which the UE transmits uplink UL subframes. For multiple RB allocations, the RB allocations can be consecutive or discontinuous based on the configuration of the uplink resource set. The RNTI can be indicated via a higher layer and can be the same as or different from the UE's C-RNTI.

[0073] The second uplink resource set can also be configured with its own set of uplink resources. The set of uplink resource candidates and the RA level can be defined or configured independently for each uplink resource set. Variable Y kIt is also possible to define uplink resource sets individually, such as for A=39829. Other hash functions, such as EPDCCH-based hashes, can also be used to determine UL resource candidates. Note that the UE can be configured with multiple uplink resource sets, and the hash functions described herein can be applied individually to each uplink resource set. In a given subframe, the UE can select an uplink resource set based on random selection or based on the number of resource blocks that the UE determines to transmit on it.

[0074] Table 5: Number of candidates for resource selection

[0075]

[0076] The implementation provides scheduling request (SR) operations under CB-UL transmissions. For example, if the UE has already transmitted in CB-UL resources but has not received an acknowledgment, the UE can send a scheduling request for SR resources. If the UE has already received an acknowledgment for the UL transmission in CB resources, the UE can release the SR resources and stop (re)transmitting scheduling requests, depending on factors such as data type. In one example, the UE can be configured to have SR and also use CB-UL resources. The UE can be configured to choose between using SR and CB-UL based on its uplink buffer state. For example, if the uplink buffer is less than a threshold, the UE can use CB-UL. Otherwise, the UE can use SR to initiate the transmission of its uplink data. In another example, the UE can always choose SR to transmit delay-tolerant uplink data to the eNB. In yet another example, the UE can choose the first available opportunity of the earlier of the CB-UL or SR transmission opportunities to initiate the transmission of uplink packets.

[0077] Implementations can provide multiple cyclic shift and / or orthogonal coverage code sequences within a single grant. For example, the eNB can improve uplink efficiency using Spatial Division Multiple Access (SDMA) or Multiple User Multiple Input Multiple Output (MU-MIMO). This can be achieved by scheduling the UE on the same time-frequency resources, but spatially separating the users by configuring them to transmit DMRS with different cyclic shifts. CB-UL can also use the same technique to improve the reception of CB-UL transmissions. In this technique, the UE can be configured to select a cyclic shift from a permitted set of cyclic shifts. For example, the UE can select from eight cyclic shifts for a given DCI format 0 uplink transmission. The exact value of the cyclic shift used by the UE can be indicated via a 3-bit field "Cyclic Shift of DMRS and OCC Index" in DCI format 0. The eNB can indicate multiple cyclic shift values ​​via downlink grants.

[0078] In the first example, the eNB can send a single downlink message containing an MCS (MCS0), a resource block allocation (RB0), and more than one cyclic shift value (CS0, CS1, CS2). Upon receiving the message, the UE can select one of the cyclic shift values ​​based on a selection criterion (CS0, CS1, CS2) and can transmit on the resource block allocation (RB0) using the indicated MCS value (MCS0). Similarly, the second UE can select one of the cyclic shift values ​​based on a selection criterion (CS0, CS1, CS2) and can transmit on the resource block allocation (RB0) using the indicated MCS value (MCS0). Therefore, the UE can select different cyclic shift values ​​and transmit on the same resource block.

[0079] In the second example, the eNB can send a first downlink message, such as a DCI, containing an MCS (MCS0) and a resource block allocation (RB0). The eNB can send a second message, such as via RRC, indicating a set of cyclic shift values ​​(CS0, CS1, CS2). After receiving the first message, the UE can select one of the cyclic shift values ​​based on a selection criterion such as CS0, CS1, CS2, where these values ​​can be obtained from the second message, and can transmit using the indicated MCS value (MCS0) on the resource block allocation (RB0). The second UE can select one of the cyclic shift values ​​based on a selection criterion such as CS0, CS1, CS2, where these values ​​can be obtained from the second message, and can transmit using the indicated MCS value (MCS0) on the resource block allocation (RB0). Thus, the UE can select different cyclic shift values ​​and transmit on the same resource block.

[0080] In another example, the eNB can configure multiple cyclic shift sets and / or orthogonal overlay code sequences via higher layers, and indicate via a DCI message a specific set of cyclic shifts and / or orthogonal overlay code sequences that can be used in a given subframe. Examples of such indications are given in Table 6. For instance, if the UE receives a DCI indicating a cyclic shift indication field "10", the UE can select a value from {CS0, CS1, CS2} based on a selection criterion to transmit its DMRS. At least one set can contain multiple cyclic shifts.

[0081] Table 6: Cyclic Shift Indicator Field

[0082]

[0083] The embodiments provide a means for selecting uplink resources from multiple grants based on UE coverage and eNB signaling. For example, the eNB can send multiple contention-based uplink grants for UEs with different coverage levels within the cell. For instance, the eNB can use a smaller payload size to send compact CB-UL grants, such as those based on DCI 1C, to assist UEs in poor coverage, and the eNB can use a slightly larger payload size to send non-compact CB-UL grants, such as those based on DCI 0 / 1A, for other UEs in improved coverage. In this case, the grant can be appropriately used by the UE based on its coverage level. For example, the UE can appropriately select the correct uplink grant to send over it using its downlink path loss measurement and, optionally, a relative threshold indicated by the eNB. Thus, if a UE detects multiple CB-UL grants with different payload sizes, it can select the UL grant to use based on a predetermined set of rules including, for example, coverage level, downlink measurement, and other parameters. If the UE detects multiple CB-UL grants with the same payload size, it can randomly select one of the grants, or each grant can have an associated probability metric, such as one embedded in the DCI, which the UE can use to determine which grant to use. An example grant is shown below. An example grant can include a 0 / 1A distinction field, a frequency hopping flag, an RB allocation field, an MCS field, a TPC for the PUSCH field, a cyclic shift for the DMRS and OCC index selection fields, a probability field, and an RA type field. The probability field, such as a 2-bit field, can indicate one of four values, such as 0.25, 0.5, 0.75, and 1, which indicates the probability that the UE can transmit on the uplink resources indicated by the grant.

[0084] As another example, the CB-UL resource sets (such as those transmitted via higher-layer signaling) for UEs with different coverage areas can be different. For instance, a UE may be closer to the cell center, for example, based on RSRP measured in specific subframes (e.g., indicated by higher layers) or in subframes containing discovery reference signals exceeding a specified threshold. A closer UE may obtain a larger CB-UL resource set, while a UE farther from the cell center may receive a smaller set for contention, even if the set includes an empty CB-UL resource set.

[0085] The implementation provides UE detection at the eNB from the received uplink. For example, if the UEID or C-RNTI is embedded in the MAC message, the eNB can detect it once the uplink TB is successfully decoded. Alternatively, the UE may be able to send its C-RNTI as uplink control information along with data on the PUSCH. In this case, for the case where UCI is associated with CB-UL, the eNB can instruct separate parameters (such as the δ parameter) to determine the number of REs used to transmit uplink control information (UCI). The C-RNTI can be encoded using an 8-bit or 16-bit CRC along with some additional information (such as BSR and / or information from the associated contention-based uplink grant).

[0086] Scrambling can be based on cyclic shifts and / or OCC indices and / or other parameters selected by the UE from control messages or using CB-RNTI. For example, a scrambling sequence for uplink PUSCH transmission can be generated using the following equation:

[0087]

[0088] Where c init This can serve as the initialization seed for the scrambling sequence generator used for PUSCH transmission, n RNTI Can represent RNTI, n s Capable of representing the number of time slots, This can be a cell identifier or a virtual cell ID, q is the MIMO codeword index (e.g., q = 1 for a single codeword transmission), and f(cs) can represent the cyclic_shift(cs) function and / or orthogonal overlay code sequence associated with the uplink transmission. As a first example, the function f(cs) = cs. As a second example, the function f(cs) = 2. x ·cs, where x can be greater than 0, transmitted by signal, or a fixed integer in the specification.

[0089] The implementation provides PHICH / HARQ retransmission for contention-based uplinks. For example, if the eNB detects a cyclic shift based on DMRS but fails to detect uplink data (e.g., when CRC fails), the eNB can signal the detected cyclic shift on the downlink to request a retransmission from the UE. For example, the eNB can transmit dedicated resources on specific UL resources addressing UEs using specific cyclic shifts, such as when the eNB knows, based on a hash function, that a particular UE can transmit with a specific cyclic shift already using that resource. However, if the eNB does not detect any transmissions on contention-based resources on the uplink, it can assume that the corresponding resource is not being used. If the eNB detects a transmission on a contention-based resource, but fails to reliably detect uplink data (e.g., when CRC fails) or even a DMRS cyclic shift or a UE using a specific cyclic shift, the eNB can use the PHICH resource corresponding to the contention-based uplink resource (e.g., via NACK) to indicate an uplink transmission failure, thus allowing the UE to handle packet failures using other means. For example, the UE can retry transmitting packets on another contention-based resource, or the UE can receive dedicated resources from the eNB after a longer delay in which it can use them to transmit packets.

[0090] LTE uplink HARQ is synchronous and supports both adaptive and non-adaptive (re)transmissions. For FDD, there can be 8 HARQ processes defined in the uplink for single-codeword transmission mode and 16 HARQ processes for dual-codeword transmission mode. In either transmission mode, for contention-based uplinks, the UE may use single-codeword transmission. For contention-based transmissions, separate HARQ processes can be specified in addition to the regular HARQ processes. Alternatively, the same HARQ processes can be shared between contention-based and non-contention-based transmissions. A NACK on the PHICH resource corresponding to uplink contention resources indicates to the UE that the corresponding uplink transmission has failed and the UE may have to retry transmitting the packet. One or more consecutive NACKs on the UE's PHICH can trigger an SR from the UE.

[0091] The embodiments can provide for power control. For example, the eNB can signal power adjustments in response to UE transmissions on specific resources where a CB uplink occurs. TPC-CB-RNTI can signal adjustments for multiple resource allocations, such as the starting RB position, within the CB resource pool. For example, for a UE transmission in subframe n on a CB-UL resource, a power adjustment can be sent in subframe n+4, which the UE can use for subsequent CB-UL transmissions. The adjustment steps can differ from those used for non-contention-based UL resources.

[0092] Depending on possible examples for power control, the UE can receive higher-layer signaling, such as via MAC or RRC, indicating the set of resources for possible contention-based (CB) PUSCH transmissions. The UE can also receive higher-layer signaling indicating open-loop power control parameters that the UE can use for CB transmissions. These parameters can include P0 and α, such as P0 for individual values ​​and α for CB transmissions. If the UE has data in its buffer, in each DL subframe n where it monitors the PDCCH / EPDCCH, the UE can check for DCI CRC scrambled with the UE's C-RNTI format 0 / 4.

[0093] If the UE does not detect a DCI intended for use by the UE, the UE can use a selection method to select a subset of UL resources from the set of resources for possible CB transmissions in UL subframe n+k. The selection method can include the UE selecting one or more of the following: TB size, number of RBs, MCS index, DMRS cyclic shift, and DMRS orthogonal overlay code sequence. To determine the transmission power for CB-PUSCH transmissions, the UE can use higher-layer parameters configured for CB transmissions (such as P0 and α), and any TPC adjustments received in the TPC command corresponding to the subset of UL resources the UE has already selected for CB-PUSCH transmissions. The TPC command can be received by the UE via a PDCCH message with DCI format 3 / 3A, scrambling the DCI CRC using an identifier associated with the CB-PUSCH transmission (such as CB-TPC-PUSCH-RNTI). PDCCH messages in DCI format 3 / 3A can be received by the UE in subframe n, such as for CB-PUSCH transmission in subframe n+k. The UE can use the DCI format 3 / 3A received in subframe n to adjust its PUSCH transmission power. Alternatively, once the UE is configured by a higher layer for a set of resources for possible CB PUSCH transmissions, it can begin monitoring DCI format 3 / 3A with a CRC scrambled by CB-TPC-PUSCH-RNTI. The DCI can contain TPC commands for multiple subsets of resources within the set of resources for possible CB transmissions. The UE can maintain a separate TPC state for each subset and update it based on the TPC commands in format 3 / 3A of each received DCI with a CRC scrambled by CB-TPC-PUSCH-RNTI. When the UE selects a specific subset for PUSCH transmission, it can use the TPC state for that subset and open-loop parameters to set its PUSCH transmission power for transmissions in that resource subset.

[0094] If the UE detects a DCI intended for use by the UE, the UE can use the RA allocation field in the DCI to determine the UL resources for PUSCH transmission in UL subframe n+k. The transmit power used by the UE for PUSCH transmission can be based on the open-loop power control parameters for regular PUSCH transmission configured by higher layers and the TPC adjustment received in the DCI (such as a DCI that also has an RA allocation field), as well as any TPC adjustment received in DCI 3 / 3A with a CRC scrambled by TPC-PUSCH-RNTI. The variable k can be a fixed number in the specification. For example, for the LTE FDD frame structure, k = 4. For the LTE TDD frame structure, k can be based on the specific UL / DL configuration for the UE, and for example, can be 4 or 6.

[0095] In the event of a conflict between sidelink resources and CB-UL resources, a sidelink UE can relinquish sidelink operations. For example, a UE can relinquish the transmission or reception of sidelink signals in CB-UL resources.

[0096] Figure 5 This is an example flowchart 500 illustrating the operation of a wireless communication device 110, such as a UE, according to a possible embodiment. Flowchart 500 can be used to signal multiple resource allocations via a single grant. At 510, flowchart 500 can begin. At 520, configuration information regarding downlink control information (DCI) messages for Physical Uplink Shared Channel (PUSCH) transmission can be obtained.

[0097] At position 530, a DCI message can be received on the Physical Downlink Control Channel (PDCCH) in the first subframe. The DCI message can indicate multiple resource allocations for the uplink carrier in the second subframe, from which the UE can select one for transmission on the uplink carrier. The DCI message can be scrambled with a Cyclic Redundancy Check (CRC) scrambled via a Radio Network Temporary Identifier (RNTI) indicated by a higher layer than the physical layer. Furthermore, the UE can have a Cell Radio Network Temporary Identifier (C-RNTI) configured by a higher layer and a Contention-Based Cell Radio Network Temporary Identifier (CBC-RNTI), and the DCI can be scrambled by the CB C-RNTI. Each of the multiple resource allocations can have the same number of resource blocks. The number of resource allocations can be indicated explicitly or implicitly in the DCI message. Additionally, the resource allocation can be within an uplink grant. For example, the DCI message can include multiple uplink grants, each of which can include at least one resource allocation. Resource allocation can include resource blocks, other information such as transmission power and reference signal configuration, and / or other information that can be used for transmission over UL. Sometimes, uplink grants can also contain information other than resource allocation.

[0098] At point 540, a selection criterion can be used to select a resource allocation from multiple resource allocations. The selection criterion can randomly select a resource allocation from multiple allocations. The selection criterion can also be based on at least one parameter measured by the UE. For example, the selection criterion can be based on measured parameters such as downlink reference received signal power (DL RSRP), signal propagation path loss, uplink buffer state, and / or any other useful parameters. Additionally, the UE can have a UE identifier, and the selection criterion can be based on at least one hash function based on the UE identifier.

[0099] At 550, parameters can be determined for transmitting data packets. According to a possible embodiment, the UE can have a Cell Radio Network Temporary Identifier (C-RNTI), and cyclic shift and / or orthogonal coverage code (OCC) can be determined for the Demodulation Reference Signal (DMRS) to transmit data packets based on the C-RNTI. In some embodiments, the orthogonal coverage code (OCC) sequence can be fixed or predetermined. According to another possible embodiment, a cyclic shift and / or orthogonal coverage code (OCC) sequence can 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 for the DMRS can be determined for transmission, and scrambling initialization for PUSCH transmission can be selected based on the at least determined cyclic shift for the DMRS used for transmission. According to another possible embodiment, an orthogonal coverage code (OCC) sequence for the DMRS can be determined for transmission, and scrambling initialization for PUSCH transmission can be selected for transmission based at least on the determined orthogonal coverage code (OCC) sequence for the DMRS.

[0100] At 560, data packets can be transmitted on the PUSCH of the selected resource allocation in the second subframe on the uplink carrier. At 570, flowchart 500 can be terminated.

[0101] Figure 6 This is an example flowchart 600 illustrating the operation of a wireless communication device 110 such as a UE according to a possible embodiment. Flowchart 600 can be used to transmit multiple cyclic shifts via a single grant. At 610, flowchart 600 can begin. At 620, configuration information regarding downlink control information (DCI) messages for Physical Uplink Shared Channel (PUSCH) transmission can be obtained.

[0102] At 630, a DCI message can be received in the first subframe. The DCI message can indicate resource allocation and modulation and coding schemes, and indicate from which the UE can select one or more cyclic shifts for transmission in the second subframe on the uplink carrier. The number of cyclic shifts indicated in the DCI message can be two or any other useful number of cyclic shifts. The DCI message can implicitly indicate the number of cyclic shifts from which the UE can select one cyclic shift for transmission. The DCI message can be received on the Physical Downlink Control Channel (PDCCH) in the first subframe. The DCI message can indicate resource allocation and modulation and coding schemes, and indicate from which the UE can select one cyclic shift for transmission. The DCI message can be scrambled with a Radio Network Temporary Identifier (RNTI) indicated by a higher layer than the physical layer. Additionally, the indication of multiple cyclic shifts can include an indication of multiple cyclic shifts and Orthogonal Cover Code (OCC) sequence pairs. The first cyclic shift can be indicated using a cyclic shift of the Demodulation Reference Signal (DMRS) and the OCC Index field for DCI messages. The second cyclic shift can be indicated using the Transmission Power Control (TPC) field for the Physical Uplink Shared Channel (PUSCH) and the New Data Indicator (NDI) field. This allows for a three-bit indication of the second cyclic shift. Cyclic shifts can also be indicated using any other useful fields or information.

[0103] At 640, a cyclic shift can be selected from multiple indicated cyclic shifts based on selection criteria. The cyclic shift and OCC sequence pair can be selected from multiple indicated cyclic shift and OCC sequence pairs based on selection criteria. At 650, scrambling initialization for PUSCH transmission can be selected based on at least the selected cyclic shift for DMRS.

[0104] At 660, data packets can be transmitted on the Physical Uplink Shared Channel (PUSCH) within the resources indicated by the resource allocation and modulation and coding scheme, using a demodulation reference signal (DMRS) based on a selected cyclic shift in the second subframe on the uplink carrier. Data packets can be transmitted on the PUSCH using DMRS based on the selected cyclic shift and OCC sequence pair. At 670, flowchart 600 can terminate.

[0105] Figure 7This is an example flowchart 700 illustrating the operation of a wireless communication device 110 such as a UE according to a possible embodiment. Flowchart 700 can be used for transmission by selecting from a set of resources configured at a higher level, such as for signaling multiple resource allocations, and the UE can select a resource allocation based on selection criteria. At 710, flowchart 700 can begin.

[0106] At 720, an indication can be obtained of the set of frequency-domain resource blocks used for possible Physical Uplink Shared Channel (PUSCH) transmissions in an uplink subframe. For example, the resource set size can be the number of resource blocks used for possible PUSCH transmissions. A subset of resource blocks can be a first subset of resource blocks. The set of frequency-domain resource blocks can be smaller than the uplink transmission bandwidth configuration. For example, the uplink transmission bandwidth configuration can be the uplink system bandwidth. The indication can be a higher-level message from a layer higher than the physical layer. For example, the higher-level message can be an RRC message, a MAC message, or any other higher-level message, or the indication can be within a physical layer message. For example, the indication can include at least a physical layer message. The indication can be implied via RACH configuration or can be otherwise indicated. The indication can also be a bitmap indication indicating whether each resource block in the set of frequency-domain resource blocks is allocated for possible PUSCH transmissions.

[0107] At 730, physical layer messages can be received. These messages can indicate a second subset of resource blocks within the set of frequency-domain resource blocks, for possible PUSCH transmissions in uplink subframes. At 740, higher-layer signaling indicating open-loop power control parameters can be received.

[0108] At 750, a subset of resource blocks for possible PUSCH transmissions can be selected from the set of frequency-domain resource blocks based on selection criteria. The selection criteria can use at least the resource set size, modulus function, and UE-associated identifier obtained from the indication. The selected subset of resource blocks can be a single resource block. The selection criteria can use one or more of the number of subframes and resource block aggregation levels. For example, the resource block aggregation level can be the number of resource blocks the UE transmits on. The UE can have a UE Cell Radio Network Temporary Identifier (C-RNTI) and can select a subset of resource blocks in response to the absence of a DCI format 0 / 4 with a Cyclic Redundancy Code (CRC) scrambled by the UE C-RNTI on the downlink (DL) control channel for uplink subframes. The selection can also include, at least based on the UE's identifier, a cyclic shift of the demodulation reference signal (DMRS) for PUSCH transmissions in the uplink subframe.

[0109] At 760, the transmission power for PUSCH transmission in a subset of resources can be determined based on open-loop power control parameters. At 770, at least one other parameter can be determined for PUSCH transmission. According to a possible embodiment, a cyclic shift can be determined for the DMRS for PUSCH transmission, and scrambling initialization for PUSCH transmission can be selected based at least on the determined cyclic shift for the DMRS for PUSCH transmission in the uplink subframe. According to a possible embodiment, an orthogonal coverage code (OCC) sequence for demodulation reference signal (DMRS) can be selected for PUSCH transmission in the uplink subframe based at least on the UE's identifier. According to a possible embodiment, an OCC sequence can be determined for the DMRS for PUSCH transmission, and scrambling initialization for PUSCH transmission can be selected based at least on the determined OCC sequence for the DMRS for PUSCH transmission in the uplink subframe.

[0110] At 780, PUSCH can be sent within a selected subset of resource blocks in the uplink subframe. PUSCH can only be sent within the selected first subset of resource blocks in the uplink subframe if the first subset of the resource block belongs to the second subset of the resource block. PUSCH can also be sent within the selected subset of resource blocks regardless of whether the first subset of the resource block belongs to the second subset. At 790, flowchart 700 can end.

[0111] It should be understood that although specific steps are shown in the figures, various additional or different steps can be performed according to the embodiments, and one or more of the specific steps can be rearranged, repeated, or completely eliminated according to the embodiments. Furthermore, some steps can be repeated on a continuous or sequential 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.

[0112] Figure 8 This is an example block diagram of a device 800, such as a wireless communication device 110, according to a possible embodiment. Device 800 may include a housing 810, a controller 820 within the housing 810, audio input and output circuitry 830 coupled to the controller 820, a display 840 coupled to the controller 820, a transceiver 850 coupled to the controller 820, an antenna 855 coupled to the transceiver 850, a user interface 860 coupled to the controller 820, a memory 870 coupled to the controller 820, and a network interface 880 coupled to the controller 820. Device 800 is capable of performing the methods described in all embodiments.

[0113] Display 840 can be a viewfinder for displaying information, a liquid crystal display (LCD), a light-emitting diode (LED) display, a plasma display, a projection display, a touchscreen, or any other device. Transceiver 850 can include a transmitter and / or a receiver. Audio input and output circuitry 830 can include a microphone, speaker, transducer, or any other audio input and output circuitry. User interface 860 can include a keypad, keyboard, buttons, touchpad, joystick, touchscreen display, another additional display, or any other device that provides an interface between the user and the electronic device. Network interface 880 can be a universal serial bus port, Ethernet port, infrared transmitter / receiver, USB port, IEEE 1398 port, WLAN transceiver, or any other interface capable of connecting the device to a network, device, or computer, and capable of sending and receiving data communication signals. Memory 870 can include random access memory, read-only memory, optical memory, flash memory, removable memory, hard disk drive, cache, or any other memory capable of being coupled to a wireless communication device.

[0114] Device 800 or controller 820 can implement any operating system, such as Microsoft. or Android TM Or any other operating system. Device operating software can be written in any programming language, such as C, C++, Java, or Visual Basic. Device software can also run on application frameworks, such as... frame, The framework, or any other application framework, may be used. The software and / or operating system may be stored in memory 870 or anywhere else on device 800. Device 800 or controller 820 may also use hardware to implement the disclosed operations. For example, controller 820 may be any programmable processor. The disclosed embodiments may also be implemented on general-purpose or special-purpose computers, programmable microprocessors, peripheral integrated circuit elements, 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.). Typically, controller 820 may be any controller or processor device or multiple devices capable of operating wireless communication devices and implementing the disclosed embodiments.

[0115] According to a possible embodiment, controller 820 can acquire configuration information regarding downlink control information (DCI) messages for transmission on the Physical Uplink Shared Channel (PUSCH). Transceiver 850 can receive DCI messages on the Physical Downlink Control Channel (PDCCH) in a first subframe. The DCI message can indicate multiple resource allocations for uplink carriers in a second subframe, from which the UE selects one for transmission on the uplink carrier. The DCI message can be scrambled with a Cyclic Redundancy Check (CRC) scrambled via a Radio Network Temporary Identifier (RNTI) indicated by a higher layer than the physical layer. Each of the multiple resource allocations can have the same number of resource blocks. Controller 820 can select a resource allocation from the multiple resource allocations using a selection criterion. Device 800 can have a UE identifier, and the selection criterion can be at least based on a hash function based on the UE identifier, or the selection criterion can be based on any other useful selection criterion. Device 800 may have a Cell Radio Network Temporary Identifier (C-RNTI), and controller 820 may determine parameters of the Demodulation Reference Signal (DMRS) for transmitting data packets based on the C-RNTI. Device 800 may also have a Cell Radio Network Temporary Identifier (C-RNTI) configured via a higher layer and a contention-based Cell Radio Network Temporary Identifier (CB C-RNTI), and may scramble the DCI using the CB C-RNTI. Controller 820 may also determine parameters of the DMRS for transmission based on at least one field indicated in the DCI message. For example, parameters may include cyclic shifts, orthogonal cover code (OCC) sequences, or other parameters for the DMRS for transmission. Transceiver 850 may transmit data packets on the PUSCH of a selected resource allocation resource in a second subframe on an uplink carrier.

[0116] According to another possible embodiment, controller 820 is capable of acquiring configuration information regarding downlink control information (DCI) messages for Physical Uplink Shared Channel (PUSCH) transmission. Transceiver 850 is capable of receiving DCI messages in a first subframe. DCI messages can indicate resource allocation and modulation and coding schemes. DCI messages can indicate multiple cyclic shifts, from which the UE can select one for transmission in a second subframe of the uplink carrier. The number of cyclic shifts indicated in the DCI message can be two or any other useful number. For example, a first cyclic shift can be indicated using cyclic shifts in the demodulation reference signal (DMRS) and orthogonal coverage code (OCC) index fields for the DCI message. A second cyclic shift can be indicated using the Transmission Power Control (TPC) field for the Physical Uplink Shared Channel (PUSCH) and the New Data Indicator (NDI) field. DCI messages can imply or explicitly indicate the number of cyclic shifts from which the UE can select one for transmission. The controller 820 is capable of selecting a cyclic shift from a plurality of indicated cyclic shifts based on selection criteria. The controller 820 is also capable of selecting scrambling initialization for PUSCH transmission based at least on the selected cyclic shift for DMRS. The transceiver 850 is capable of transmitting data packets on the PUSCH in the resources indicated by resource allocation and modulation and coding schemes, and using DMRS based on the selected cyclic shift in the second subframe on the uplink carrier.

[0117] Depending on the implementation, transceiver 850 can receive DCI messages on the Physical Downlink Control Channel (PDCCH) in the first subframe. The DCI message can indicate resource allocation and modulation and coding schemes, and indicate to the UE from which to select one of several cyclic shifts for transmission. The DCI message can be a cyclic redundancy check (CRC) message scrambled with a Radio Network Temporary Identifier (RNTI) indicated by a higher layer than the physical layer.

[0118] According to another possible implementation, the indications of multiple cyclic shifts can include indications of multiple cyclic shift and orthogonal overlay code (OCC) sequence pairs. The controller 820 can select a cyclic shift and OCC sequence pair from the multiple indicated cyclic shift and OCC sequence pairs based on selection criteria. The transceiver 850 can transmit data packets on the PUSCH using DMRS based on the selected cyclic shift and OCC sequence pair.

[0119] According to another possible embodiment, controller 820 is capable of acquiring an indication of a set of frequency domain resource blocks in an uplink subframe for possible PUSCH transmissions. The indication can be a bitmap indication indicating whether each resource block in the set of frequency domain resource blocks is allocated for possible PUSCH transmissions. The indication can also be any other indication.

[0120] The controller 820 can 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 can use at least the resource set size obtained from the indication, modulus function, and identifier associated with device 800. The selection criteria can also use one or more of the subframe number and resource block aggregation level. The transceiver 850 can transmit PUSCH within the selected subset of resource blocks in an uplink subframe.

[0121] Depending on the implementation, a subset of resource blocks can be a first subset of resource blocks. The indication can be a higher-level message from a layer higher than the physical layer. Transceiver 850 can receive physical layer messages. Physical layer messages can indicate a second subset of resource blocks within the set of frequency-domain resource blocks for possible PUSCH transmission in the uplink subframe. Transceiver 850 can only transmit PUSCH in the first subset of selected resource blocks in the uplink subframe if the first subset of resource blocks belongs to the second subset of resource blocks.

[0122] According to another possible implementation, transceiver 850 is capable of receiving higher-layer signaling indicating open-loop power control parameters. Controller 820 is capable of determining the transmission power for PUSCH transmissions in a subset of resources based on the open-loop power control parameters. Controller 820 is also capable of selecting parameters for the demodulation reference signal (DMRS) for PUSCH transmissions in uplink subframes, at least based on the identifier of device 800. Controller 820 is also capable of determining parameters for the DMRS for PUSCH transmissions and can select scrambling initialization for PUSCH transmissions, at least based on the determined parameters for the DMRS for PUSCH transmissions in uplink subframes. The determined parameters can be cyclic shift, OCC, or any other parameters that can be used for the DMRS for PUSCH transmissions in uplink subframes.

[0123] The methods disclosed herein can be implemented on a programmable processor. However, the controller, flowchart, and modules can also be implemented on general-purpose or special-purpose computers, programmable microprocessors or microcontrollers and peripheral integrated circuit elements, integrated circuits, hardware electronic devices or logic circuits (such as discrete component circuits), programmable logic devices, etc. Generally, any device residing in a finite state machine capable of implementing the flowcharts shown in the figures can be used to implement the processor functions of this disclosure.

[0124] Although this disclosure has been described with reference to specific embodiments, it will be apparent to those skilled in the art that many alternatives, modifications, and variations will be readily apparent. For example, various components of the embodiments may be interchanged, added, or substituted in other embodiments. Similarly, not all elements in every schematic diagram are necessary for the operation of the disclosed embodiments. For example, those skilled in the art will be able to make and use the teachings of this disclosure by simply employing the elements of the independent claims. Therefore, the embodiments of this disclosure set forth herein are intended to be illustrative rather than restrictive. Various changes may be made without departing from the spirit and scope of this disclosure.

[0125] In this document, relational terms (such as "first," "second," etc.) may be used only to distinguish one entity or action from another, without necessarily requiring or implying any actual such relationship or order between such entities or actions. The phrase "at least one of" followed by a list is defined as indicating one, some, or all (but not necessarily all) elements in the list. The terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes the list of elements does not only include those elements, but may include other elements not expressly listed in or inherent to those processes, methods, articles, or apparatus. Without further constraints, an element connected by "a," "an," etc., does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes that element. Furthermore, the term "another" is defined as at least a second or more. As used herein, the terms "including," "having," etc., are defined as "comprising." In addition, the background section is written as the inventor's own understanding of the context of some embodiments prior to the filing date, and includes the inventor's own awareness of any problems with the prior art and / or problems experienced in their work.

Claims

1. A method in a device, the method comprising: Transmit configuration information about downlink control information messages used for physical uplink shared channel transmission; In the first subframe, the downlink control information message is sent to the user equipment on the physical downlink control channel. The downlink control information message indicates multiple resource allocations and multiple cyclic shifts for uplink carriers in the second subframe. The user equipment selects one resource allocation and one cyclic shift from the multiple resource allocations for transmission on the uplink. The downlink control information message is scrambled with a cyclic redundancy check via a radio network temporary identifier indicated by a higher layer than the physical layer. On the uplink carrier, in the second subframe, a demodulation reference signal based on a selected cyclic shift (DMRS) is used to receive data packets on the physical uplink shared channel from the user equipment in the resources of a selected resource allocation, wherein the selected resource allocation is chosen from the plurality of resource allocations.

2. The method according to claim 1, wherein, Each of the multiple resource allocations has the same number of resource blocks.

3. The method according to claim 1, wherein, The cyclic shift of the demodulation reference signal used for the received data packets is based on the cell radio network temporary identifier of the user equipment that sent the data packets.

4. The method according to claim 1, wherein, The cyclic shift of the demodulation reference signal used for the received data packets is based on at least one field indicated in the downlink control information message.

5. The method according to claim 1, wherein, The orthogonal overlay code sequence used for the demodulation reference signal of the received data packets is based on the cell radio network temporary identifier of the user equipment that sent the data packets.

6. The method according to claim 1, wherein, The orthogonal overlay code sequence for the demodulation reference signal used for the received data packets is based on at least one field indicated in the downlink control information message.

7. The method according to claim 1, wherein, The number of resources allocated is explicitly indicated in the downlink control information message.

8. The method according to claim 1, wherein, The number of resources allocated is implied in the downlink control information message.

9. The method according to claim 1, wherein, The selection criterion for choosing the selected resource allocation is to randomly select a resource allocation from the plurality of resource allocations.

10. The method according to claim 1, wherein, The selection criteria used to select the chosen resource allocation are based on at least one parameter measured by the user equipment.

11. The method according to claim 1, in, The user equipment has a user equipment identifier, and The selection criteria for choosing the selected resource allocation are based at least on a hash function, which is based on the user equipment identifier.

12. The method according to claim 1, wherein, The user equipment has a cell radio network temporary identifier and a contention-based cell radio network temporary identifier configured via a higher layer, and the downlink control information is scrambled by the contention-based cell radio network temporary identifier.

13. The method according to claim 1, wherein, The scrambling initialization for the data packets received on the physical uplink shared channel is based at least on a determined cyclic shift of the demodulation reference signal for the transmission of the data packets through the user equipment.

14. The method according to claim 1, wherein, The scrambling initialization for the data packets received on the physical uplink shared channel is based at least on a determined orthogonal overlay code sequence of the demodulation reference signal used for the transmission of the data packets through the user equipment.

15. An apparatus comprising: Controller, which controls the operation of the device; as well as transceiver, the transceiver Transmit configuration information about downlink control information messages used for physical uplink shared channel transmission; In the first subframe, the downlink control information message is sent to the user equipment on the physical downlink control channel. The downlink control information message indicates multiple resource allocations and multiple cyclic shifts for uplink carriers in the second subframe. The user equipment selects one resource allocation and one cyclic shift from the multiple resource allocations for transmission on the uplink. The downlink control information message is scrambled with a cyclic redundancy check via a radio network temporary identifier indicated by a higher layer than the physical layer. as well as On the uplink carrier, in the second subframe, a demodulation reference signal based on a selected cyclic shift (DMRS) is used to receive data packets on the physical uplink shared channel from the user equipment in the resources of a selected resource allocation, wherein the selected resource allocation is chosen from the plurality of resource allocations.

16. The device according to claim 15, wherein, Each of the multiple resource allocations has the same number of resource blocks.

17. The device according to claim 15, wherein, The cyclic shift of the demodulation reference signal used for the received data packets is based on the cell radio network temporary identifier of the user equipment that sent the data packets.

18. The device according to claim 15, wherein, At least one field indicated in the downlink control information message includes parameters for determining a demodulation reference signal for the transmission of the data packets through the user equipment.

19. The device according to claim 15, in, The controller determines selection criteria for choosing a resource allocation from the plurality of resource allocations based at least on a hash function, the hash function being based on the identifier of the user equipment; and The transceiver sends selection criteria to the user equipment for selecting the resource allocation.

20. The device according to claim 15, wherein, The downlink control information is scrambled by the user equipment’s contention-based cell radio network temporary identifier, wherein the contention-based cell radio network temporary identifier is configured by a higher layer.

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