WO2020199229A1

WO2020199229A1 - Techniques for implementing ack/nack in wireless communications

Info

Publication number: WO2020199229A1
Application number: PCT/CN2019/081625
Authority: WO
Inventors: Changlong Xu; Chao Wei; Qiaoyu Li; Jian Li
Original assignee: Qualcomm Incorporated
Priority date: 2019-04-05
Filing date: 2019-04-05
Publication date: 2020-10-08

Abstract

Aspects described herein relate to communicating ACK/NACK indication between a User equipment (UE) and a base station. For example, the UE may transmit an uplink transmission to the base station. The base station may receive and decode the uplink transmission. The base station may transmit an indication (ACK/NACK) indicating whether the uplink transmission from the UE was successfully received decoded by the base station. If NACK is received, the UE may retransmit the uplink transmission without receiving a further uplink grant for the retransmission.

Description

TECHNIQUES FOR IMPLEMENTING ACK/NACK IN WIRELESS COMMUNICATIONS

BACKGROUND

Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to implementing acknowledgement and non-acknowledgement (ACK/NACK) with regard to reception of wireless communication.

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems, and single-carrier frequency division multiple access (SC-FDMA) systems.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. For example, a fifth generation (5G) wireless communications technology (which can be referred to as 5G new radio (5G NR) ) is envisaged to expand and support diverse usage scenarios and applications with respect to current mobile network generations. In an aspect, 5G communications technology can include: enhanced mobile broadband addressing human-centric use cases for access to multimedia content, services and data; ultra-reliable-low latency communications (URLLC) with certain specifications for latency and reliability; and massive machine type communications, which can allow a very large number of connected devices and transmission of a relatively low volume of non-delay-sensitive information.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

According to an example, a method of wireless communication is provided. The method may include transmitting, by a base station, an uplink grant to a User Equipment (UE) via a Physical Downlink Control Channel (PDCCH) and receiving, by the base station, an uplink transmission via a Physical Uplink Shared Channel (PUSCH) . The method may further include transmitting, by the base station, an indication to the UE indicating whether the uplink transmission is successfully received by the base station via the PUSCH.

In some examples, the method may further include decoding, by the base station, the uplink transmission received from the UE, and generating, by the base station, the indication based on the decoding. The indication may include at least one bit selectively indicating acknowledgement (ACK) or non-acknowledgement (NACK) of successful decoding of the uplink transmission by the base station.

In some examples of the method, the indication may include a first bit indicating whether a first portion of the uplink transmission is successfully decoded by the base station and a second bit indicating whether a second portion of the uplink transmission is successfully decoded by the base station.

In some examples of the method, the indication may be transmitted from the base station to the UE via a Downlink Control Information (DCI) transmission. The DCI transmission may be transmitted via a Physical Downlink Control Channel (PDCCH) in common search space.

In some examples of the method, the DCI transmission may be masked by a dedicated Radio Network Temporary ID (RNTI) shared by a group of UE’s including the UE. In some examples of the method, the DCI transmission may include a plurality of bits each indicating ACK or NACK for uplink transmissions from UE’s in the group. In some examples of the method, locations of ACK/NACK bits in the DCI for each UE in the group may be indicated by a UE index transmitted to the UE in the uplink grant.

In some examples of the method, the indication may indicate that the uplink transmission was not successfully received by the base station. The method may further include receiving, by the base station, a retransmission of the uplink transmission from the UE, without transmitting an additional uplink grant to the UE for the retransmission. In some examples of the method, the retransmission may be received by the base station via same communication resources as the uplink transmission and the retransmission may include a same Modulation and Coding Scheme (MCS) as the uplink transmission.

In another example, a method for wireless communications is provided. The method may include receiving, by a User Equipment (UE) , an uplink grant from a base station via a Physical Downlink Control Channel (PDCCH) and transmitting, by the UE, an uplink transmission via a Physical Uplink Shared Channel (PUSCH) . The method may further include receiving, by the UE, an indication from the base station indicating whether the uplink transmission is successfully received by the base station via the PUSCH.

In some examples of the method, the indication may include at least one bit selectively indicating acknowledgement (ACK) or non-acknowledgement (NACK) of successful decoding of the uplink transmission by the base station. In some examples of the method, the indication may inclue a first bit indicating whether a first portion of the uplink transmission is successfully decoded by the base station and a second bit indicating whether a second portion of the uplink transmission is successfully decoded by the base station.

In some examples, the DCI transmission may be masked by a dedicated Radio Network Temporary ID (RNTI) shared by a group of UE’s including the UE. The DCI transmission may include a plurality of bits each indicating ACK or NACK for uplink transmissions from UE’s in the group.

In some examples, the method may further include, receiving a UE index in the uplink grant from the base station and locating one or more ACK/NACK bits for the UE in the DCI based on the UE index.

In some examples of the method, the indication may indicate that the uplink transmission was not successfully received by the base station. The method may further include transmitting a retransmission of the uplink transmission to the base station, without receiving an additional uplink grant for the retransmission from the base station. In some examples of the method, the retransmission may be transmitted via same communication resources as the uplink transmission and the retransmission comprises a same Modulation and Coding Scheme (MCS) as the uplink transmission.

In another aspect, an apparatus for wireless communication is provided that includes a transceiver, a memory configured to store instructions, and one or more processors communicatively coupled with the transceiver and the memory. The one or more processors are configured to execute the instructions to perform the operations of methods described herein.

In still another aspect, an apparatus for wireless communication is provided that includes means for performing the operations of methods described herein. In yet another aspect, a computer-readable medium is provided including code executable by one or more processors to perform the operations of methods described herein.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will hereinafter be described in conjunction with the appended drawings, provided to illustrate and not to limit the disclosed aspects, wherein like designations denote like elements, and in which:

FIG. 1 illustrates an example of a wireless communication system, in accordance with various aspects of the present disclosure;

FIG. 2 is a block diagram illustrating an example of a UE, in accordance with various aspects of the present disclosure;

FIG. 3 is a block diagram illustrating an example of a base station, in accordance with various aspects of the present disclosure;

FIGs. 4A, 4B, 4C, and 4D are diagrams illustrating examples of a DL frame structure, DL channels within the DL frame structure, an UL frame structure, and UL channels within the UL frame structure, respectively.

FIG. 5 is a process flow illustrating an example of a method for communicating ACK/NACK indication between a UE and a base station, in accordance with various aspects of the present disclosure;

FIG. 6 is a diagram illustrating resource structures of a DCI including a plurality of ACK/NACK bits, in accordance with various aspects of the present disclosure;

FIG. 7 is a flow chart illustrating an example of a method for transmitting an ACK/NACK indication, in accordance with various aspects of the present disclosure;

FIG. 8 is a flow chart illustrating an example of a method for receiving an ACK/NACK indication, in accordance with various aspects of the present disclosure;

FIG. 9 is a block diagram illustrating an example of a MIMO communication system including a base station and a UE, in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect (s) may be practiced without these specific details.

The described features generally relate to communicating acknowledgement of uplink transmissions between a User Equipment (UE) and a base station. The UE may send an uplink scheduling request to the base station to request for uplink transmission. The base station may respond with an uplink grant for the UE to send an uplink transmission. After receiving the uplink grant, the UE may transmit the uplink transmission to the base station based on the uplink grant.

Conventionally, the base station does not respond with an acknowledgement or non-acknowledgement after receiving the uplink transmission from the UE. In an event that the uplink transmission is not successfully received or decoded by the base station, the base station may send another uplink grant to the UE for the UE to re-transmit the uplink transmission. However, when there is a large number of UEs (e.g., massive terminals) , a large number of PDCCH (uplink grants) are needed for the large number of uplink transmissions and/or uplink re-transmissions. Further, this is also not efficient for frequent uplink transmissions with small packets, such as in Internet of Things (IoT) . Without ACK/NACK indications, UE may be required to perform PDCCH detection frequently to wait for UL grants for retransmission, which may consume additional UE power.

In some aspects of the present disclosure, techniques are provided that allow for communication of acknowledgment or non-acknowledgement (ACK/NACK) that indicate whether the base station has successfully received and decoded an uplink transmission from the UE. For example, after the base station successfully receives and decodes an uplink transmission from the UE, the base station may generate and transmit ACK/NACK to the UE indicating whether the uplink transmission has been successfully received (and decoded) . In some examples, the ACK/NACK may be transmitted in a Downlink Control Information (DCI) via PDCCH in common search space.

In some examples, the DCI may be masked by a dedicated Radio Network Temporary ID (RNTI) that allows the UE to identify the DCI in a common search space. The RNTI may be predefined for a group of UEs and the DCI may include ACK/NACK bits for each of the UEs in the group. In particular, the location of the ACK/NACK bit in DCI for a particular UE may be indicated by a UE Index that was communicated to the UE in a previous uplink grant.

In some examples, when the UE received a NACK indicating that the uplink transmission was not successfully received by the base station, the UE may re-transmit the uplink transmission to the base station, without having to wait to receive an uplink grant for the re-transmission. In particular, for the uplink re-transmission, the UE may use the same resources as the previous uplink transmission with predefined interval and with the same Modulation and Coding Scheme (MCS) .

Accordingly, the proposed techniques provide an efficient mechanism for communicating ACK/NACK of uplink transmissions received from UEs. This may reduce the number of PDCCH for re-transmission uplink grants. This also may conserve UE power by avoiding unnecessary blind detection for re-transmission uplink grants, because the UE may receive an ACK indication to confirm that the uplink transmission is successfully received.

The described features will be presented in more detail below with reference to FIGS. 1-9.

As used in this application, the terms “component, ” “module, ” “system” and the like are intended to include a computer-related entity, such as but not limited to hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components can communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets, such as data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal.

Techniques described herein may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other systems. The terms “system” and “network” may often be used interchangeably. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA) , etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD) , etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM) . An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM ^TM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS) . 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP) . CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies, including cellular (e.g., LTE) communications over a shared radio frequency spectrum band. The description below, however, describes an LTE/LTE-A system for purposes of example, and LTE terminology is used in much of the description below, although the techniques are applicable beyond LTE/LTE-Aapplications (e.g., to fifth generation (5G) new radio (NR) networks or other next generation communication systems) .

The following description provides examples, and is not limiting of the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in other examples.

Various aspects or features will be presented in terms of systems that can include a number of devices, components, modules, and the like. It is to be understood and appreciated that the various systems can include additional devices, components, modules, etc. and/or may not include all of the devices, components, modules etc. discussed in connection with the figures. A combination of these approaches can also be used.

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN) ) can include base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and/or a 5G Core (5GC) 190. The base stations 102 may include macro cells (high power cellular base station) and/or small cells (low power cellular base station) . The macro cells can include base stations. The small cells can include femtocells, picocells, and microcells. In an example, the base stations 102 may also include gNBs 180, as described further herein. In one example, some nodes of the wireless communication system may have a modem 240 and communicating component 242 for communicating ACK/NACK of uplink transmissions, and some nodes may have a modem 340 and uplink communication component 342 for receiving uplink communication, as described herein. Though a UE 104 is shown as having the modem 240 and communicating component 242 and a base station 102/gNB 180 is shown as having the modem 340 and uplink communication component 342, this is one illustrative example, and substantially any node or type of node may include a modem 240 and communicating component 242 and/or a modem 340 and uplink communication component 342 for providing corresponding functionalities described herein.

The base stations 102 configured for 4G LTE (which can collectively be referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) may interface with the EPC 160 through backhaul links 132 (e.g., using an S1 interface) . The base stations 102 configured for 5G NR (which can collectively be referred to as Next Generation RAN (NG-RAN) ) may interface with 5GC 190 through backhaul links 184. In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160 or 5GC 190) with each other over backhaul links 134 (e.g., using an X2 interface) . The backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with one or more UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102' may have a coverage area 110' that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group, which can be referred to as a closed subscriber group (CSG) . The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102 /UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (e.g., for x component carriers) used for transmission in the DL and/or the UL direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL) . The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .

In another example, certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152 /AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

The small cell 102' may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102' may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102', employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.

A base station 102, whether a small cell 102' or a large cell (e.g., macro base station) , may include an eNB, gNodeB (gNB) , or other type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies, and/or near mmW frequencies in communication with the UE 104. When the gNB 180 operates in mmW or near mmW frequencies, the gNB 180 may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW /near mmW radio frequency band has extremely high path loss and a short range. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range. A base station 102 referred to herein can include a gNB 180.

The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

The 5GC 190 may include a Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196. The AMF 192 can be a control node that processes the signaling between the UEs 104 and the 5GC 190. Generally, the AMF 192 can provide QoS flow and session management. User Internet protocol (IP) packets (e.g., from one or more UEs 104) can be transferred through the UPF 195. The UPF 195 can provide UE IP address allocation for one or more UEs, as well as other functions. The UPF 195 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services.

The base station may also be referred to as a gNB, Node B, evolved Node B (eNB) , an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a transmit reception point (TRP) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or 5GC 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) . The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

In an example, communicating component 242 may transmit an uplink transmission to base station 102 based on an uplink grant. Uplink communication component 342 may receive and decode the uplink transmission. Based on whether the uplink communication is successfully received and decoded, uplink communication component 342 may transmit an indication (ACK/NACK) to UE 104. As described further herein, communicating component 242 may receive the indication (ACK/NACK) indicating whether base station 102 successfully received the uplink transmission. Communication component 242 may re-transmit the uplink transmission based on the indication.

Turning now to FIGS. 2-9, aspects are depicted with reference to one or more components and one or more methods that may perform the actions or operations described herein, where aspects in dashed line may be optional. Although the operations described below in FIGS. 5, 7, and 8 are presented in a particular order and/or as being performed by an example component, it should be understood that the ordering of the actions and the components performing the actions may be varied, depending on the implementation. Moreover, it should be understood that the following actions, functions, and/or described components may be performed by a specially-programmed processor, a processor executing specially-programmed software or computer-readable media, or by any other combination of a hardware component and/or a software component capable of performing the described actions or functions.

Referring to FIG. 2, one example of an implementation of UE 104 may include a variety of components, some of which have already been described above and are described further herein, including components such as one or more processors 212 and memory 216 and transceiver 202 in communication via one or more buses 244, which may operate in conjunction with modem 240 and/or communicating component 242 to receive RRC configuration messages and/or to transmit RRC configuration responses.

In an aspect, the one or more processors 212 can include a modem 240 and/or can be part of the modem 240 that uses one or more modem processors. Thus, the various functions related to communicating component 242 may be included in modem 240 and/or processors 212 and, in an aspect, can be executed by a single processor, while in other aspects, different ones of the functions may be executed by a combination of two or more different processors. For example, in an aspect, the one or more processors 212 may include any one or any combination of a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receiver processor, or a transceiver processor associated with transceiver 202. In other aspects, some of the features of the one or more processors 212 and/or modem 240 associated with communicating component 242 may be performed by transceiver 202.

Also, memory 216 may be configured to store data used herein and/or local versions of applications 275 or communicating component 242 and/or one or more of its subcomponents being executed by at least one processor 212. Memory 216 can include any type of computer-readable medium usable by a computer or at least one processor 212, such as random access memory (RAM) , read only memory (ROM) , tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, memory 216 may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes defining communicating component 242 and/or one or more of its subcomponents, and/or data associated therewith, when UE 104 is operating at least one processor 212 to execute communicating component 242 and/or one or more of its subcomponents.

Transceiver 202 may include at least one receiver 206 and at least one transmitter 208. Receiver 206 may include hardware, firmware, and/or software code executable by a processor for receiving data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium) . Receiver 206 may be, for example, a radio frequency (RF) receiver. In an aspect, receiver 206 may receive signals transmitted by at least one base station 102. Additionally, receiver 206 may process such received signals, and also may obtain measurements of the signals, such as, but not limited to, Ec/Io, signal-to-noise ratio (SNR) , reference signal received power (RSRP) , received signal strength indicator (RSSI) , etc. Transmitter 208 may include hardware, firmware, and/or software code executable by a processor for transmitting data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium) . A suitable example of transmitter 208 may including, but is not limited to, an RF transmitter.

Moreover, in an aspect, UE 104 may include RF front end 288, which may operate in communication with one or more antennas 265 and transceiver 202 for receiving and transmitting radio transmissions, for example, wireless communications transmitted by at least one base station 102 or wireless transmissions transmitted by UE 104. RF front end 288 may be connected to one or more antennas 265 and can include one or more low-noise amplifiers (LNAs) 290, one or more switches 292, one or more power amplifiers (PAs) 298, and one or more filters 296 for transmitting and receiving RF signals.

In an aspect, LNA 290 can amplify a received signal at a desired output level. In an aspect, each LNA 290 may have a specified minimum and maximum gain values. In an aspect, RF front end 288 may use one or more switches 292 to select a particular LNA 290 and its specified gain value based on a desired gain value for a particular application.

Further, for example, one or more PA (s) 298 may be used by RF front end 288 to amplify a signal for an RF output at a desired output power level. In an aspect, each PA 298 may have specified minimum and maximum gain values. In an aspect, RF front end 288 may use one or more switches 292 to select a particular PA 298 and its specified gain value based on a desired gain value for a particular application.

Also, for example, one or more filters 296 can be used by RF front end 288 to filter a received signal to obtain an input RF signal. Similarly, in an aspect, for example, a respective filter 296 can be used to filter an output from a respective PA 298 to produce an output signal for transmission. In an aspect, each filter 296 can be connected to a specific LNA 290 and/or PA 298. In an aspect, RF front end 288 can use one or more switches 292 to select a transmit or receive path using a specified filter 296, LNA 290, and/or PA 298, based on a configuration as specified by transceiver 202 and/or processor 212.

As such, transceiver 202 may be configured to transmit and receive wireless signals through one or more antennas 265 via RF front end 288. In an aspect, transceiver may be tuned to operate at specified frequencies such that UE 104 can communicate with, for example, one or more base stations 102 or one or more cells associated with one or more base stations 102. In an aspect, for example, modem 240 can configure transceiver 202 to operate at a specified frequency and power level based on the UE configuration of the UE 104 and the communication protocol used by modem 240.

In an aspect, modem 240 can be a multiband-multimode modem, which can process digital data and communicate with transceiver 202 such that the digital data is sent and received using transceiver 202. In an aspect, modem 240 can be multiband and be configured to support multiple frequency bands for a specific communications protocol. In an aspect, modem 240 can be multimode and be configured to support multiple operating networks and communications protocols. In an aspect, modem 240 can control one or more components of UE 104 (e.g., RF front end 288, transceiver 202) to enable transmission and/or reception of signals from the network based on a specified modem configuration. In an aspect, the modem configuration can be based on the mode of the modem and the frequency band in use. In another aspect, the modem configuration can be based on UE configuration information associated with UE 104 as provided by the network during cell selection and/or cell reselection.

In an aspect, communicating component 242 may optionally include an uplink transmission component 252 for transmitting uplink transmission to one or more base stations, and/or an uplink acknowledgement receiving component 254 for receiving and processing ACK/NACK of uplink transmission from one or more base stations.

In an aspect, the processor (s) 212 may correspond to one or more of the processors described in connection with the UE in FIG. 9. Similarly, the memory 216 may correspond to the memory described in connection with the UE in FIG. 9.

Referring to FIG. 3, one example of an implementation of base station 102 (e.g., a base station 102 and/or gNB 180, as described above) may include a variety of components, some of which have already been described above, but including components such as one or more processors 312 and memory 316 and transceiver 302 in communication via one or more buses 344, which may operate in conjunction with modem 340 and Uplink communication component 342 for receiving and processing uplink transmissions from UEs.

The transceiver 302, receiver 306, transmitter 308, one or more processors 312, memory 316, applications 375, buses 344, RF front end 388, LNAs 390, switches 392, filters 396, PAs 398, and one or more antennas 365 may be the same as or similar to the corresponding components of UE 104, as described above, but configured or otherwise programmed for base station operations as opposed to UE operations.

In an aspect, uplink communication component 342 may include a uplink receiving component 352 for receiving uplink transmissions from one or more UEs, and/or a uplink acknowledgement component 354 for generating and transmitting an indication (ACK/NACK) indicating whether uplink transmissions are successfully received by base station 102.

In an aspect, the processor (s) 312 may correspond to one or more of the processors described in connection with the base station in FIG. 9. Similarly, the memory 316 may correspond to the memory described in connection with the base station in FIG. 9.

FIG. 4A is a diagram 400 illustrating an example of a DL frame structure. FIG. 4B is a diagram 430 illustrating an example of channels within the DL frame structure. FIG. 4C is a diagram 450 illustrating an example of an UL frame structure. FIG. 4D is a diagram 480 illustrating an example of channels within the UL frame structure. Other wireless communication technologies may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes. Each subframe may include two consecutive time slots. A resource grid may be used to represent the two time slots, each time slot including one or more time concurrent resource blocks (RBs) (also referred to as physical RBs (PRBs) ) . The resource grid is divided into multiple resource elements (REs) . For a normal cyclic prefix, an RB contains 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols (for DL, OFDM symbols; for UL, SC-FDMA symbols) in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB contains 12 consecutive subcarriers in the frequency domain and 6 consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 4A, some of the REs carry DL reference (pilot) signals (DL-RS) for channel estimation at the UE. The DL-RS may include cell-specific reference signals (CRS) (also sometimes called common RS) , UE-specific reference signals (UE-RS) , and channel state information reference signals (CSI-RS) . FIG. 4A illustrates CRS for

antenna ports

0, 1, 2, and 3 (indicated as R0, R1, R2, and R3, respectively) , UE-RS for antenna port 5 (indicated as R5) , and CSI-RS for antenna port 15 (indicated as R) . FIG. 2B illustrates an example of various channels within a DL subframe of a frame. The physical control format indicator channel (PCFICH) is within symbol 0 of slot 0, and carries a control format indicator (CFI) that indicates whether the physical downlink control channel (PDCCH) occupies 1, 2, or 3 symbols (FIG. 2B illustrates a PDCCH that occupies 3 symbols) . The PDCCH carries downlink control information (DCI) within one or more control channel elements (CCEs) , each CCE including nine RE groups (REGs) , each REG including four consecutive REs in an OFDM symbol. A UE may be configured with a UE-specific enhanced PDCCH (ePDCCH) that also carries DCI. The ePDCCH may have 2, 4, or 8 RB pairs (FIG. 2B shows two RB pairs, each subset including one RB pair) . The physical hybrid automatic repeat request (ARQ) (HARQ) indicator channel (PHICH) is also within symbol 0 of slot 0 and carries the HARQ indicator (HI) that indicates HARQ ACK /negative NACK feedback based on the physical uplink shared channel (PUSCH) . The primary synchronization channel (PSCH) may be within symbol 6 of slot 0 within

subframes

0 and 5 of a frame. The PSCH carries a primary synchronization signal (PSS) that is used by a UE to determine subframe/symbol timing and a physical layer identity. The secondary synchronization channel (SSCH) may be within symbol 5 of slot 0 within

subframes

0 and 5 of a frame. The SSCH carries a secondary synchronization signal (SSS) that is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI) . Based on the PCI, the UE can determine the locations of the aforementioned DL-RS. The physical broadcast channel (PBCH) , which carries a master information block (MIB) , may be logically grouped with the PSCH and SSCH to form a synchronization signal (SS) block. The MIB provides a number of RBs in the DL system bandwidth, a PHICH configuration, and a system frame number (SFN) . The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs) , and paging messages.

As illustrated in FIG. 4C, some of the REs carry demodulation reference signals (DM-RS) for channel estimation at the base station. The UE may additionally transmit sounding reference signals (SRS) in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL. FIG. 4D illustrates an example of various channels within an UL subframe of a frame. A physical random access channel (PRACH) may be within one or more subframes within a frame based on the PRACH configuration. The PRACH may include six consecutive RB pairs within a subframe. The PRACH allows the UE to perform initial system access and achieve UL synchronization. A physical uplink control channel (PUCCH) may be located on edges of the UL system bandwidth. The PUCCH carries uplink control information (UCI) , such as scheduling requests, a channel quality indicator (CQI) , a precoding matrix indicator (PMI) , a rank indicator (RI) , and HARQ ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR) , a power headroom report (PHR) , and/or UCI.

FIG. 5 illustrates a process flow of an example of a method 500 for communicating ACK/NACK for uplink transmissions between a UE and a base station. In an example, a UE 104 and a base station 102 may perform the operations and/or functions described in method 500 using one or more of the components described in FIGS. 1-3.

In method 500, at step 502, UE 104 may determine to transmit data to base station 102 in an uplink transmission. UE 104 may first transmit an uplink scheduling request which requests base station 104 to schedule communication resources for an uplink transmission from UE 104. At step 504, base station 102 may generate an uplink grant in response to UE 104’s uplink scheduling request. The uplink grant may be transmitted from base station 102 to UE 104 in a downlink control information (DCI) via PDCCH. The uplink grant may designate communication resources and modulation and coding scheme (MCS) for UE 104 to perform an uplink transmission to base station 102 via PUSCH. In some examples, the uplink grant may further include a UE index that may be used later by UE 104 to identify locations of uplink transmission ACK/NACK bits in a DCI.

In method 500, at step 506, after receiving the uplink grant, UE 104 may transmit the uplink transmission via PUSCH to base station 102. At step 508, base station 102 may receive and decode the uplink transmission. Base station 102 may generate an indication to UE 104 as an acknowledgement or non-acknowledgement of whether the uplink transmission has been successfully received and decoded by base station 102. In particular, the indication may include ACK or NACK using an ACK/NACK bit (e.g., 1 for ACK and 0 for NACK) .

In method 500, at step 510, base station 102 may transmit the indication (e.g., ACK/NACK of uplink transmission to UE 104 in a DCI via PDCCH. In some examples, the DCI may include a plurality of ACK/NACK bits indicating ACK/NACK of uplink transmissions from a group of UEs. For example, FIG. 6 illustrates a DCI 600 including a plurality of ACK/NACK bits 602a-602n. ACK/NACK bit 602a may indicate ACK/NACK for uplink transmission from UE1 and ACK/NACK bit 602b may indicate ACK/NACK for uplink transmission from UE2. As such, one DCI may include a plurality of ACK/NACK bits for a group of UEs.

In some examples, a UE may have more than one ACK/NACK bits. For example, a first ACK/NACK bit may indicate for a first portion of an uplink transmission and a second ACK/NACK bit may indicate for a second portion of the uplink transmission.

In some examples, the group of UEs may be associated with a dedicated Radio Network Temporary ID (RNTI) . As shown in FIG. 6, DCI 600 may be CRC masked by RNTI 610. The dedicated DCI 600 may be transmitted in common search space with dedicated RNTI which may be configured by higher layer (e.g., RRC) .

In some examples, the location of ACK/NACK bits for each UE in DCI 600 may be indicated using a UE index. The UE index may be included in the DCI for uplink grant previously provided to the UE to configure the uplink transmission. For example, a new field with several bits may be added to the uplink grant DCI to indicate the UE index (e.g., 5 bits for 32 UEs, 6bits for 64 UEs) . As such, UE 104 may use the UE index to locate the ACK/NACK bit (s) associate with UE 104 in DCI 600.

In method 500, at step 512, UE 104 may receive the ACK/NACK from base station 102 and may determine whether re-transmission is needed. For example, UE 104 may perform blind detection of PDCCH with dedicated DCI in common search space using the pre-defined RNTI of the group of UEs. After the dedicated DCI is identified, UE 104 may locate the ACK/NACK bit associated with UE 104 using the UE index previously received along with the uplink grant (in step 502) .

If the ACK/NACK bit indicates ACK, base station 102 successfully received and decode the uplink transmission, UE 104 may flush the HARQ buffer and may report the result to upper layer (e.g., RRC) . If the ACK/NACK bit indicates NACK, base station 102 did not receive and decode the uplink transmission successfully, UE 104 may retransmit the uplink transmission, without receiving further uplink grant for the retransmission. For example, UE 104 may perform retransmission of the MAC PDU in the HARQ buffer. In some examples, the retransmission may use the same resource as the original or previous uplink transmission. In some examples, the retransmission may use a predefined slot, such as the next uplink transmission slot. In some examples, the redundancy version may be applied in a sequence, such as 0, 1, 2, 3 for the retransmission.

Accordingly, the above examples provide an efficient scheme for communicating ACK/NACK for uplink transmissions from a group of UEs. This may reduce the number uplink grants needed for retransmissions. This may also allow for UE power saving by avoiding unnecessary blind detection of retransmission uplink grants.

FIG. 7 illustrates a flow chart of an example of a method 700 for communicating ACK/NACK indications. In an example, a base station 102 may perform the functions described in method 700 using one or more of the components described in FIGS. 1 and 3.

In method 700, at Block 702, base station 102 may transmit an uplink grant to UE 104 in a DCI via PDCCH. In an aspect, uplink communication component 342, e.g., in conjunction with processor (s) 312, memory 316, transceiver 302, etc., may transmit the uplink grant to UE 104. The uplink grant may be transmitted in a DCI including a UE index indicating a location of ACK/NACK bit for UE 104. The uplink grant may be transmitted in response to UE 104’s uplink scheduling request. The uplink grant may designate resources and MCS for an uplink transmission (PUSCH) . Block 702 may include or may correspond to step 504 of FIG. 5, as described above.

In method 700, at Block 704, base station 102 may receive an uplink transmission (PUSCH) from UE 104. Base station 102 may receive and may decode the uplink transmission form UE 104. In an aspect, uplink receiving component 352, e.g., in conjunction with processor (s) 312, memory 316, transceiver 302, etc., may receive and may decode the uplink transmission from UE 104. In an aspect, Block 704 may include or correspond to step 508 in FIG. 5, as described above.

In method 700, at Block 706, base station 102 may transmit an indication to UE 104 indicating whether the uplink transmission was successfully received (and decoded) . In an aspect, uplink acknowledgement component 354, e.g., in conjunction with processor (s) 312, memory 316, transceiver 302, and etc., may transmit the indication to UE 104. For example, base station 102 may indicate ACK with an ACK/NACK bit if the uplink transmission from UE 104 was successfully received and decoded by base station 102. Base station 102 may indicate NACK with an ACK/NACK bit if the uplink transmission from UE 104 was not successfully received and decoded by base station 102.

In some examples, base station 102 may allocate the ACK/NACK bit in an DCI based on an UE index associated with UE 104. The DCI may be masked by an RNTI associated with a group of UEs to which UE 104 belongs. The DCI may be transmitted in common search space with the dedicated RNTI which is configured by higher layer. In an aspect, Block 706 may include or correspond to step 510 in FIG. 5, as described above.

Accordingly, the proposed techniques in method 700 may allow base station 102 to indicate to UE 104 whether an uplink transmission (PUSCH) from UE 104 was successfully received and decoded by base station 102.

FIG. 8 illustrates a flow chart of an example of a method 800 for receiving an ACK/NACK indication. In an example, a UE 104 may perform the functions described in method 800 using one or more of the components described in FIGS. 1-2.

In method 800, at Block 802, UE 104 may receive an uplink grant from base station 102 (via PDCCH) . In an aspect, uplink transmission component 252, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, communicating component 242, etc., may receive the uplink grant from base station 102. The uplink grant may be transmitted in a DCI. The DCI may include a UE index which may be used later by UE 104 to identify a location of ACK/NACK bit for UE 104. The uplink grant may be transmitted in response to UE 104’s uplink scheduling request. The uplink grant may designate resources and MCS for an uplink transmission (PUSCH) from UE 104. In some aspect, Block 802 may include or correspond to step 504 in FIG. 5 as described above.

In method 800, at Block 804, UE 104 may transmit an uplink transmission (PUSCH) to base station 102. In an aspect, uplink transmission component 252, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, communicating component 242, etc., may transmit the uplink transmission to base station 102. In some aspect, Block 804 may include or correspond to step 506 in FIG. 5, as described above.

In method 800, at Block 806, UE 104 may receive an indication from base station 102 indicating whether the uplink transmission was successfully received by the base station. In some examples, UE 104 may perform blink detection for PDCCH with dedicated DCI in common search space using a pre-defined RNTI associated with UE 104. UE 104 may further locate ACK/NACK bit for UE 104 using the UE index previously received along with the uplink grant DCI (e.g., Block 802) . In an aspect, uplink acknowledgement receiving component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, communicating component 242, etc., may receive the indication from base station 102. In some aspect, Block 806 may include or correspond to step 510 in FIG. 5, as described above.

Accordingly, the proposed techniques in method 800 may allow for UE 104 to receive ACK/NACK of an uplink transmission. If ACK, UE 104 may stop blind searching for retransmission uplink grants. If NACK, UE 104 may perform retransmission without further uplink grants. This may reduce search time and conserve UE power.

FIG. 9 is a block diagram of a MIMO communication system 900 including a base station 102 and a UE 104. The MIMO communication system 900 may illustrate aspects of the wireless communication access network 100 described with reference to FIG. 1. The base station 102 may be an example of aspects of the base station 102 described with reference to FIG. 1. The base station 102 may be equipped with

antennas

934 and 935, and the UE 104 may be equipped with

antennas

952 and 953. In the MIMO communication system 900, the base station 102 may be able to send data over multiple communication links at the same time. Each communication link may be called a “layer” and the “rank” of the communication link may indicate the number of layers used for communication. For example, in a 2x2 MIMO communication system where base station 102 transmits two “layers, ” the rank of the communication link between the base station 102 and the UE 104 is two.

At the base station 102, a transmit (Tx) processor 920 may receive data from a data source. The transmit processor 920 may process the data. The transmit processor 920 may also generate control symbols or reference symbols. A transmit MIMO processor 930 may perform spatial processing (e.g., precoding) on data symbols, control symbols, or reference symbols, if applicable, and may provide output symbol streams to the transmit modulator/

demodulators

932 and 933. Each modulator/demodulator 932 through 933 may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream. Each modulator/demodulator 932 through 933 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a DL signal. In one example, DL signals from modulator/

demodulators

932 and 933 may be transmitted via the

antennas

934 and 935, respectively.

The UE 104 may be an example of aspects of the UEs 104 described with reference to FIGS. 1-2. At the UE 104, the

UE antennas

952 and 953 may receive the DL signals from the base station 102 and may provide the received signals to the modulator/

demodulators

954 and 955, respectively. Each modulator/demodulator 954 through 955 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each modulator/demodulator 954 through 955 may further process the input samples (e.g., for OFDM, etc. ) to obtain received symbols. A MIMO detector 956 may obtain received symbols from the modulator/

demodulators

954 and 955, perform MIMO detection on the received symbols, if applicable, and provide detected symbols. A receive (Rx) processor 958 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, providing decoded data for the UE 104 to a data output, and provide decoded control information to a processor 980, or memory 982.

The processor 980 may in some cases execute stored instructions to instantiate a communicating component 242 (see e.g., FIGS. 1 and 2) .

On the uplink (UL) , at the UE 104, a transmit processor 964 may receive and process data from a data source. The transmit processor 964 may also generate reference symbols for a reference signal. The symbols from the transmit processor 964 may be precoded by a transmit MIMO processor 966 if applicable, further processed by the modulator/demodulators 954 and 955 (e.g., for SC-FDMA, etc. ) , and be transmitted to the base station 102 in accordance with the communication parameters received from the base station 102. At the base station 102, the UL signals from the UE 104 may be received by the

antennas

934 and 935, processed by the modulator/

demodulators

932 and 933, detected by a MIMO detector 936 if applicable, and further processed by a receive processor 938. The receive processor 938 may provide decoded data to a data output and to the processor 940 or memory 942.

The processor 940 may in some cases execute stored instructions to instantiate a RRC component 342 (see e.g., FIGS. 1 and 3) .

The components of the UE 104 may, individually or collectively, be implemented with one or more ASICs adapted to perform some or all of the applicable functions in hardware. Each of the noted modules may be a means for performing one or more functions related to operation of the MIMO communication system 900. Similarly, the components of the base station 102 may, individually or collectively, be implemented with one or more ASICs adapted to perform some or all of the applicable functions in hardware. Each of the noted components may be a means for performing one or more functions related to operation of the MIMO communication system 900.

The above detailed description set forth above in connection with the appended drawings describes examples and does not represent the only examples that may be implemented or that are within the scope of the claims. The term “example, ” when used in this description, means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and apparatuses are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, computer-executable code or instructions stored on a computer-readable medium, or any combination thereof.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a specially-programmed device, such as but not limited to a processor, a digital signal processor (DSP) , an ASIC, a FPGA or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, or any combination thereof designed to perform the functions described herein. A specially-programmed processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A specially-programmed processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a non-transitory computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a specially programmed processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) .

Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the common principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Furthermore, although elements of the described aspects and/or embodiments may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect and/or embodiment may be utilized with all or a portion of any other aspect and/or embodiment, unless stated otherwise. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

A method of wireless communication, comprising:

transmitting, by a base station, an uplink grant to a User Equipment (UE) via a Physical Downlink Control Channel (PDCCH) ;

receiving, by the base station, an uplink transmission via a Physical Uplink Shared Channel (PUSCH) ; and

transmitting, by the base station, an indication to the UE indicating whether the uplink transmission is successfully received by the base station via the PUSCH.
The method of claim 1, further comprising:

decoding, by the base station, the uplink transmission received from the UE, and

generating, by the base station, the indication based on the decoding,

wherein the indication comprises at least one bit selectively indicating acknowledgement (ACK) or non-acknowledgement (NACK) of successful decoding of the uplink transmission by the base station.
The method of claim 2, wherein the indication comprises a first bit indicating whether a first portion of the uplink transmission is successfully decoded by the base station and a second bit indicating whether a second portion of the uplink transmission is successfully decoded by the base station.
The method of claim 2, wherein the indication is transmitted from the base station to the UE via a Downlink Control Information (DCI) transmission.
The method of claim 4, wherein the DCI transmission is transmitted via a Physical Downlink Control Channel (PDCCH) in common search space.
The method of claim 4, wherein the DCI transmission is masked by a dedicated Radio Network Temporary ID (RNTI) shared by a group of UE’s including the UE.
The method of claim 6, wherein the DCI transmission comprises a plurality of bits each indicating ACK or NACK for uplink transmissions from UE’s in the group.
The method of claim 7, wherein locations of ACK/NACK bits in the DCI for each UE in the group are indicated by a UE index transmitted to the UE in the uplink grant.
The method of claim 1,

wherein the indication indicates that the uplink transmission was not successfully received by the base station, and

wherein the method further comprises receiving, by the base station, a retransmission of the uplink transmission from the UE, without transmitting an additional uplink grant to the UE for the retransmission;
The method of claim 9, wherein the retransmission is received by the base station via same communication resources as the uplink transmission and the retransmission comprises a same Modulation and Coding Scheme (MCS) as the uplink transmission.
A method of wireless communication, comprising:

receiving, by a User Equipment (UE) , an uplink grant from a base station via a Physical Downlink Control Channel (PDCCH) ;

transmitting, by the UE, an uplink transmission via a Physical Uplink Shared Channel (PUSCH) ; and

receiving, by the UE, an indication from the base station indicating whether the uplink transmission is successfully received by the base station via the PUSCH.
The method of claim 11, wherein the indication comprises at least one bit selectively indicating acknowledgement (ACK) or non-acknowledgement (NACK) of successful decoding of the uplink transmission by the base station.
The method of claim 12, wherein the indication comprises a first bit indicating whether a first portion of the uplink transmission is successfully decoded by the base station and a second bit indicating whether a second portion of the uplink transmission is successfully decoded by the base station.
The method of claim 12, wherein the indication is transmitted from the base station to the UE via a Downlink Control Information (DCI) transmission.
The method of claim 14, wherein the DCI transmission is transmitted via a Physical Downlink Control Channel (PDCCH) in common search space.
The method of claim 14, wherein the DCI transmission is masked by a dedicated Radio Network Temporary ID (RNTI) shared by a group of UE’s including the UE.
The method of claim 6, wherein the DCI transmission comprises a plurality of bits each indicating ACK or NACK for uplink transmissions from UE’s in the group.
The method of claim 17, further comprising:

receiving a UE index in the uplink grant from the base station; and

locating one or more ACK/NACK bits for the UE in the DCI based on the UE index.
The method of claim 11,

wherein the indication indicates that the uplink transmission was not successfully received by the base station, and

wherein the method further comprises transmitting a retransmission of the uplink transmission to the base station, without receiving an additional uplink grant for the retransmission from the base station;
The method of claim 19, wherein the retransmission is transmitted via same communication resources as the uplink transmission and the retransmission comprises a same Modulation and Coding Scheme (MCS) as the uplink transmission.