WO2020164011A1

WO2020164011A1 - Group-based downlink control information

Info

Publication number: WO2020164011A1
Application number: PCT/CN2019/074963
Authority: WO
Inventors: Changlong Xu; Chao Wei; Hao Xu
Original assignee: Qualcomm Incorporated
Priority date: 2019-02-13
Filing date: 2019-02-13
Publication date: 2020-08-20

Abstract

Methods, systems, and apparatuses for wireless communication are disclosed. In one exemplary aspect, a user equipment (UE) is associated with a first group of UEs for receiving group control messages from a base station. The UE detects a first control message in a control channel transmission. The first control message includes a plurality of group control messages, and each group control message may provide downlink control information (DCI) for a plurality of UEs in an associated group of UEs including the first group of UEs. The UE locates a first group control message which provides DCI for the first group of UEs in the first control message. The UE decodes the first group control message and may perform blind decoding on a plurality of decoding candidates within the first group control message to detect DCI for the UE. The UE may communicate with the base station based at least in part on detecting the DCI.

Description

GROUP-BASED DOWNLINK CONTROL INFORMATION

BACKGROUND Technical Field

The technology described below relates generally to wireless communications and more specifically to use of group-based downlink control information.

Introduction

Wireless communications 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 capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of 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, (e.g., a Long Term Evolution (LTE) system, or a New Radio (NR) system) . A wireless multiple-access communication system may include a number of base stations or access network nodes, each simultaneously supporting communication for multiple communication devices also known as user equipment (UE) .

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, regional, national, and even global level. For example, a fifth generation (5G) wireless communications technology (which may be referred to as new radio (NR) ) is being developed to expand and support diverse usage scenarios and applications with respect to current mobile network generations. Different aspects of 5G communications technology may 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 for a very large number of connected devices and transmission of a relatively low volume of non-delay-sensitive information. As the demand for such different types of service increases, however, further improvements in NR communications technology and beyond are needed.

BRIEF SUMMARY

Generally, the disclosed techniques provide group-based downlink control information for efficient use of control channel resources and improved device performance. In one aspect, the spectral efficiency of control channel transmissions is improved by grouping a plurality wireless devices according to channel conditions and sending group-based DCI messages using a different modulation and coding schemes with the different groups. In one aspect, the disclosed group-based DCI (also referred to herein as “G-DCI, ” or “group control messages” ) may enable a significant reduction in cyclic-redundancy check (CRC) overhead through use of a group-level CRC for each G-DCI, and a UE-specific CRC having a reduced size for individual DCI payloads of a group-based DCI message. In one aspect, the disclosed group-based DCI messages may include common DCI that may be shared by UEs in a corresponding user group as well as UE-specific DCI that is specific to an individual wireless device. This may further reduce the number of DCI bits or the length of the DCI message. The innovative channel-aware, group-based approach to DCI transmission, the reduction of CRC overhead, and savings from use of common DCI may increase the number of users for which DCI can be transmitted on a given amount of control channel resources without increasing device complexity.

According to the disclosed techniques, a plurality of group-based DCI messages may be arranged to form an aggregate control message. The aggregate control message may utilize a large code block size and a performance improvement may be realized via a corresponding coding gain. In one aspect, blind decoding to locate the aggregate control message may be avoided by indicating to wireless devices on which resources the aggregate control message is transmitted. By avoiding blind decoding, power efficiency at the device may be improved and latency may be reduced. In one aspect, group-based DCI forming the aggregate control message may be transmitted on contiguous control channel resources. In one aspect, the aggregate control message may have a variable-size that depends upon the number of scheduled users in the plurality of group-based DCI messages.

A method of wireless communication performed by a user equipment (UE) is described. The method may include determining that the UE is associated with a first group of UEs for receiving group control messages from a base station. The method may include detecting a first control message in a control channel transmission. The first control message may include a plurality of group control messages, and each group control message in the plurality of group control messages may provide downlink control information (DCI) for a plurality of UEs in an associated group of UEs including the first group of UEs. The method may include determining a location of a first group control message in the plurality of group control messages. The first group control message may provide DCI for the first group of UEs. The method may include decoding the first group control message and performing blind decoding on a plurality of decoding candidates in the first group control message to detect DCI for the UE. The method may include communicating with the base station based at least in part on the detected DCI for the UE.

A apparatus is described. The apparatus may be a user equipment (UE) or a part of a UE. The apparatus may include means for determining that the UE is associated with a first group of UEs for receiving group control messages from a base station. The apparatus may include means for detecting a first control message in a control channel transmission. The first control message may include a plurality of group control messages and each group control message in the plurality of group control messages may provide downlink control information (DCI) for a plurality of UEs in an associated group of UEs including the first group of UEs. The apparatus may include means for determining a location of a first group control message in the plurality of group control messages. The first group control message may provide DCI for the first group of UEs. The apparatus may include means for decoding the first group control message and means for performing blind decoding on a plurality of decoding candidates in the first group control message to detect DCI for the UE. The apparatus may also include means for communicating with the base station based at least in part on the the detected DCI for the UE.

Another apparatus is described. The apparatus may be a user equipment (UE) or a part of a UE. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be operable, when executed by the processor, to cause the apparatus to determine that the UE is associated with a first group of UEs for receiving group control messages from a base station. The instructions may be operable to cause the apparatus to detect a first control message in a control channel transmission. The first control message may include a plurality of group control messages. Each group control message in the plurality of group control messages may provide downlink control information (DCI) for a plurality of UEs in an associated group of UEs including the first group of UEs. The instructions may be operable to cause the apparatus to determine a location of a first group control message in the plurality of group control messages. The first group control message may provide DCI for the first group of UEs. The instructions may be operable to cause the apparatus to decode the first group control message and perform blind decoding on a plurality of decoding candidates in the first group control message to detect DCI for the UE. The instructions may also be operable to cause the apparatus to communicate with the base station based at least in part on the detected DCI for the UE.

A non-transitory computer readable medium storing code for wireless communication by a user equipment (UE) is described. The code comprises instructions executable by a processor to determine that the UE is associated with a first group of UEs for receiving group control messages from a base station. The code comprises instructions executable by the processor to detect a first control message in a control channel transmission. The first control message may include a plurality of group control messages. Each group control message in the plurality of group control messages may provide downlink control information (DCI) for a plurality of UEs in an associated group of UEs including the first group of UEs. The code comprises instructions executable by the processor to determine a location of a first group control message in the plurality of group control messages. The first group control message may provide DCI for the first group of UEs. The code comprises instructions executable by the processor to decode the first group control message and perform blind decoding on a plurality of decoding candidates in the first group control message to detect DCI for the UE. The code may also comprise instructions executable by the processor to communicate with the base station based at least in part on the detected DCI for the UE.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the wireless device may receive a second control message from the base station. The second control message may indicate the availability of the first control message in the control channel transmission. In some aspects, the second message includes scheduling information for the plurality of group control messages. In some aspects, the second control message indicates a starting location of the first control message in the control channel transmission. In some aspects, the plurality of group control messages comprises at least the first group control message and a second group control message. The modulation and coding scheme (MCS) used with the first group control message may be different than the MCS used with the second group control message. In some aspects, blind decoding by the wireless device includes detecting that a decoding candidate in the plurality of decoding candidates of the first group control message is scrambled with an identifier of the UE. In some aspects, at least a portion of the DCI in the first group control message is common DCI that is common to the UEs of the first group of UEs. The common DCI may include an uplink/downlink scheduling indication, a modulation and coding scheme (MCS) for use with data channel transmissions, a new data indicator (NDI) for hybrid automatic repeat request (HARQ) operation, or any combination thereof.

A method of wireless communication is described. The method may be performed by a base station and may include associating a user equipment (UE) with a first group of UEs for receiving group control messages from the base station. The method may include determining downlink control information (DCI) for transmission to the UE in a first group control message associated with the first group of UEs. The method may include sending a first control message in a control channel transmission. The first control message may comprise a plurality of group control messages, including the first group control message. Each group control message in the plurality of group control messages may provide DCI for a plurality of UEs in an associated group of UEs. The first group control message may include a group cyclic redundancy check (CRC) to facilitate decoding by UEs in the first group of UEs. DCI for transmission to the UE may be sent in one of a plurality of decoding candidates defined in the first group control message using an identifier of the UE. The method may include receiving a communication from the UE in response to sending the first control message.

An apparatus for wireless communication is described. The apparatus may be a base station or a part of a base station. The apparatus may include means for associating a user equipment (UE) with a first group of UEs for receiving group control messages. The apparatus may include means for determining downlink control information (DCI) for transmission to the UE in a first group control message associated with the first group of UEs. The apparatus may include means for sending a first control message in a control channel transmission. The first control message may comprise a plurality of group control messages, including the first group control message. Each group control message in the plurality of group control messages may provide DCI for a plurality of UEs in an associated group of UEs. The first group control message may include a group cyclic redundancy check (CRC) to facilitate decoding by UEs in the first group of UEs, and the DCI for transmission to the UE may be sent in one of a plurality of decoding candidates defined in the first group control message using an identifier of the UE. The apparatus may include means for receiving a communication from the UE in response to sending the first control message.

Another apparatus is described. The apparatus may be a base station or a part of a base station. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be operable, when executed by the processor, to cause the apparatus to associate a user equipment (UE) with a first group of UEs for receiving group control messages. The instructions may be operable to cause the apparatus to determine downlink control information (DCI) for transmission to the UE in a first group control message associated with the first group of UEs. The instructions may be operable to cause the apparatus to send a first control message in a control channel transmission. The first control message may comprise a plurality of group control messages, including the first group control message. Each group control message in the plurality of group control messages may provide DCI for a plurality of UEs in an associated group of UEs. The first group control message may include a group cyclic redundancy check (CRC) to facilitate decoding by UEs in the first group of UEs, and the DCI for transmission to the UE may be sent in one of a plurality of decoding candidates defined in the first group control message using an identifier of the UE. The instructions may be operable to cause the apparatus to receive a communication from the UE in response to sending the first control message.

A non-transitory computer readable medium storing code for wireless communication is described. The code comprises instructions executable by a processor of a user equipment (UE) to associate the UE with a first group of UEs for receiving group control messages from the base station. The code comprises instructions executable by the processor to determine downlink control information (DCI) for transmission to the UE in a first group control message associated with the first group of UEs. The code comprises instructions executable by the processor to send a first control message in a control channel transmission. The first control message may comprise a plurality of group control messages, including the first group control message. Each group control message in the plurality of group control messages may provide DCI for a plurality of UEs in an associated group of UEs. The first group control message may include a group cyclic redundancy check (CRC) to facilitate decoding by UEs in the first group of UEs, and DCI for transmission to the UE may be sent in one of a plurality of decoding candidates defined in the first group control message using an identifier of the UE. The code comprises instructions executable by the processor to receive a communication from the UE in response to sending the first control message.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the base station may send a second control message comprising an indication of the availability of the first control message in the control channel transmission. The second control message may be sent on predetermined time-frequency resources and may indicate a location of the first control message in the control channel transmission. In one aspect, the second control message may include scheduling information for the plurality of group control messages and may indicate a number of UEs scheduled for DCI transmission in each group control message. In one aspect, the plurality of group control messages includes at least the first group control message and a second group control message. The MCS used with the first group control message may be different than the MCS used with the second group control message. In one aspect, at least a portion of the DCI in the first group control message is common DCI that is shared by the UEs of the first group of UEs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a system for wireless communication in accordance with aspects of the present disclosure.

FIG. 2A shows aspects of an exemplary group downlink control information indicator and group-based downlink control information in accordance with aspects of the present disclosure.

FIG. 2B shows additional aspects of the exemplary group downlink control information indicator in accordance with the present disclosure.

FIG. 2C shows additional aspects of the group-based downlink control message in accordance with the present disclosure.

FIGs. 3-5 show block diagrams of a wireless device that supports group-based downlink control information in accordance with aspects of the present disclosure.

FIGs. 6-8 show block diagrams of a base station that supports group-based downlink control information in accordance with aspects of the present disclosure.

FIGs. 9-10 illustrate exemplary methods of wireless communication utilizing group-based downlink control information in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

Advanced wireless communication systems such as New Radio (NR) from the 3 ^rd Generation Partnership Project (3GPP) will introduce new service types and are expected to support an increasingly large number of users. With a growing number of users, control channel capacity will be an important consideration. New designs may be needed to increase the efficiency of control channel resource utilization while maintaining support for flexible device scheduling. Device complexity will also be an important consideration in control channel design. A requirement for increased blind decoding, for example, may have a negative impact on device operation by raising power consumption, decreasing battery life, and potentially increasing latency associated with control channel processing. The present disclosure, in some aspects, provides techniques for transmission of group-based downlink control information. The disclosed techniques may enable a more efficient utilization of control channel resources while avoiding an increase in blind decoding requirements or a requirement for additional device complexity.

Downlink control information (DCI) may be transmitted to all users as a single group. With this approach, coordination between devices may be possible as each device may be aware of the resource allocations of all other devices. However, such a DCI transmission suffers when different devices experience different channel conditions. Different channel conditions may require, for example, the network to use a modulation and coding scheme (MCS) for DCI transmission that is suitable for the user experiencing the worst conditions. This lowers spectral efficiency and potentially results in a reduced control channel capacity as the number of users grows. Other approaches may send DCI on a per-user basis and may achieve some flexibility to address varying channel conditions through the use of multiple aggregation levels. As with a single-group DCI approach, reliance on per-user DCI may also have significant drawbacks for efficient control channel utilization and device complexity. Also, as with the single-group DCI approach, these drawbacks may become more pronounced as the number of users increases. For example, as the number of aggregation levels used for sending DCI increases, the burden on devices to monitor a large number of decoding candidates may also increase. Moreover, each per-user DCI may incur a substantial overhead in relation to its payload. Some systems, for instance, may utilize a 24-bit CRC for error detection when sending a 32-bit DCI payload. With a per-user DCI approach, the network may also need to duplicate DCI that is common to multiple users in each per-user DCI message.

Techniques described in the present disclosure may avoid these problems and may offer better performance than conventional approaches. In some examples, a base station may group users for sending DCI in a control channel transmission based on channel conditions. Users with similar channel conditions may be grouped together and a different MCS may be utilized for control channel transmission to the different control groups. The group MCS for each control group may be configured by radio resource control (RRC) signaling. In this way, high spectral efficiency transmissions can be utilized for wireless devices operating in good channel conditions and low spectral efficiency transmissions can be utilized for devices operating in poor channel conditions.

In some aspects, a group control message is generated for each group of users. A group control message may carry DCI for a plurality of users in an associated group and may include a CRC that is scrambled with a corresponding radio network temporary identifier (RNTI) of the group. A plurality of group control messages may be aggregated for transmission on a downlink control channel. The plurality of group control messages may be referred to as an “aggregate control message” without loss of generality. In some aspects, the group-based DIC messages may occupy contiguous control channel resources. The starting resource location of the aggregate control message may be indicated to wireless devices. In one aspect, wireless devices may locate and decode the group control message associated with their respective user groups in the aggregate control message. In some aspects, each wireless device may perform blind decoding on resource locations within its group control message to detect the availability of its DCI.

Aspects of the disclosure are initially described in the context of a wireless communications system and relate to transmission of group-based DCI in a control channel. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to the foregoing. While aspects and embodiments are described in this application using various illustrations and examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. The descriptions herein may be implemented across different platforms, devices, systems, shapes, sizes, packaging arrangements. For example, embodiments and/or uses may come about via integrated chip embodiments and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc. ) . Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the present disclosure. In some practical settings, devices incorporating described aspects and features may also include additional components and features for implementation and practice of claimed and described embodiments. For example, transmission and reception of wireless signals may include a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, filters, processor (s) , interleaver, adders/summers, etc. ) . It is intended that aspects of the present disclosure herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution.

FIG. 1 illustrates an example of a system 100 in accordance with various aspects of the present disclosure. System 100 includes base stations 105, UEs 115, and a core network 130. In some examples, system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, or a New Radio (NR) network. In some cases, system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

Base stations 105 may wirelessly communicate with UEs 115 via one or more base station antennas. As described herein, a base station 105 may include or may be referred to as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation Node B or giga-nodeB (either of which may be referred to as a gNB) , a Home NodeB, a Home eNodeB, or some other suitable terminology. System 100 may include base stations 105 of different types (e.g., macro or small cell base stations) . The UEs 115 described herein may be able to communicate with various types of base stations 105 and network equipment including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like.

Each base station 105 may be associated with a particular geographic coverage area 110 in which communications with various UEs 115 is supported. Each base station 105 may provide communication coverage for a respective geographic coverage area 110 via communication links 125, and communication links 125 between a base station 105 and a UE 115 may include one or more carriers. Communication links 125 shown in system 100 may include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions, from a base station 105 to a UE 115. Downlink transmissions may also be called forward link transmissions while uplink transmissions may also be called reverse link transmissions.

The geographic coverage area 110 for a base station 105 may be divided into sectors making up only a portion of a corresponding geographic coverage area 110, and each sector may be associated with a cell. For example, each base station 105 may provide communication coverage for a macro cell, a small cell, a hot spot, or other types of cells, or various combinations thereof. In some examples, a base station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or by different base stations 105. System 100 may include, for example, a heterogeneous LTE/LTE-A or NR network in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

The term “cell” refers to a logical communication entity used for communication with a base station 105 (e.g., over a carrier) , and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID) , a virtual cell identifier (VCID) ) operating via the same or a different carrier. In some examples, the cells may support different service and/or device types (e.g., machine-type communication (MTC) , narrowband Internet-of-Things (NB-IoT) , enhanced mobile broadband (eMBB) , ultra-reliable low-latency (URLLC) communications, and others) . In some cases, the term “cell” may refer to a portion of a geographic coverage area 110 (e.g., a sector) over which the logical entity operates.

UEs 115 may be dispersed throughout system 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a wireless device, a mobile device, a mobile station, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client. A UE 115 may also be a electronic device such as a cellular phone, a personal digital assistant (PDA) , a tablet computer, a laptop computer, a medical device, industrial equipment, a sensor, an entertainment device, and/or a personal computer. In some examples, a UE 115 may also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, or the like, which may be implemented in various articles such as appliances, vehicles, meters, or the like.

Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously) . In some examples half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for UEs 115 include entering a power saving “deep sleep” mode when not engaging in active communications, or operating over a limited bandwidth (e.g., according to narrowband communications) . In some cases, UEs 115 may be designed to support critical functions (e.g., mission critical functions) , and system 100 may be configured to provide ultra-reliable communications for these functions.

Base stations 105 may communicate with the core network 130 and with one another. For example, base stations 105 may interface with the core network 130 through backhaul links 132 (e.g., via an S1 or other interface) . Base stations 105 may communicate with one another over backhaul links 134 (e.g., via an X2 or other interface) either directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130) . The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) , which may include at least one mobility management entity (MME) , at least one serving gateway (S-GW) , and at least one Packet Data Network (PDN) gateway (P-GW) . The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the EPC. User IP packets may be transferred through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation as well as other functions. The P-GW may be connected to a network operator’s IP services. Operator IP services may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched (PS) Streaming Service.

System 100 may operate using one or more frequency bands, typically in the range of 300 MHz to 300 GHz. Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band, since the wavelengths range from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features. However, the waves may penetrate structures sufficiently for a macro cell to provide service to UEs 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter range (e.g., less than 100 km) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz. System 100 may also operate in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) , also known as the millimeter band. In some examples, system 100 may support millimeter wave (mmW) communications between UEs 115 and base stations 105, and EHF antennas of the respective devices may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate use of antenna arrays within a UE 115. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. Techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

In some examples, base station 105 or UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. For example, system 100 may use a transmission scheme between a transmitting device (e.g., a base station 105) and a receiving device (e.g., a UE 115) , where the transmitting device is equipped with multiple antennas and the receiving devices are equipped with one or more antennas. MIMO communications may employ multipath signal propagation to increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream, and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) where multiple spatial layers are transmitted to multiple devices.

Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105 or a UE 115) to shape or steer an antenna beam (e.g., a transmit beam or receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying certain amplitude and phase offsets to signals carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .

In one example, a base station 105 may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE 115. For instance, some signals (e.g. synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by the base station 105 or a receiving device, such as a UE 115) a beam direction for subsequent transmission and/or reception by the base station 105. Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115) . In some examples, the beam direction associated with transmissions along a single beam direction may be determined based at least in in part on a signal that was transmitted in different beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions, and the UE 115 may report to the base station 105 an indication of the signal it received with a highest signal quality, or an otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted in one or more directions by a base station 105, a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) , or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device) .

A receiving device (e.g., a UE 115, which may be an example of a mmW receiving device) may try multiple receive beams when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive beams or receive directions. In some examples a receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal) . The single receive beam may be aligned in a beam direction determined based on listening according to different receive beam directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based on listening according to multiple beam directions) .

Base station 105 may transmit a control channel, such as a physical downlink control channel (PDCCH) , in order to convey downlink control information (DCI) to UE 115. The DCI can be UE-specific (dedicated) or cell-specific (common) and placed in different dedicated and common search spaces within the PDCCH. A single PDCCH may carry DCI associated with multiple UEs 115. A particular UE 115, therefore, may need to be able to recognize the its DCI in the PDCCH. To that end, a UE 115 may be assigned one or more UE-specific search spaces in the control channel, and may also utilize common search spaces allocated to the UE 115 as well as other UEs 115 in the system 100. The UE 115 may attempt to decode the DCI by performing a process known as blind decoding, during which multiple decoding attempts are carried out in the search spaces until a DCI message is detected or all of the decoding candidates have been checked. Additionally, or alternatively, group-based DCI may be utilized in the PDCCH as described herein. In some aspects, UEs 115 may separately receive an indicator of the group-based DCI which may indicate a location of the G-DCI message in the PDCCH, a size of the G-DCI message, scheduling information for different control groups of the G-DCI message, etc.

In some cases, the antennas of a base station 105 or UE 115 may be located within one or more antenna arrays, which may support MIMO operations, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some cases, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

In some cases, system 100 may be a packet-based network that operate according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may in some cases perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use hybrid automatic repeat request (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a base station 105 or core network 130 supporting radio bearers for user plane data. At the Physical (PHY) layer, transport channels may be mapped to physical channels.

In some cases, UEs 115 and base stations 105 may support retransmissions of data to increase the likelihood that data is received successfully. HARQ feedback is one technique of increasing the likelihood that data is received correctly over a communication link 125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC) ) , forward error correction (FEC) , and retransmission (e.g., automatic repeat request (ARQ) ) . HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., signal-to-noise conditions) . In some cases, a wireless device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval.

The term “carrier” refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over a communication link 125. For example, a carrier of a communication link 125 may include a portion of a radio frequency spectrum band that is operated according to physical layer channels for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a pre-defined frequency channel (e.g., an E-UTRA absolute radio frequency channel number (EARFCN) ) , and may be positioned according to a channel raster for discovery by UEs 115. Carriers may be downlink or uplink (e.g., in an FDD mode) , or be configured to carry downlink and uplink communications (e.g., in a TDD mode) . In some examples, signal waveforms transmitted over a carrier may be made up of multiple sub-carriers (e.g., using multi-carrier modulation (MCM) techniques such as OFDM or DFT-s-OFDM) .

The organizational structure of the carriers may be different for different radio access technologies (e.g., LTE, LTE-A, NR, etc. ) . For example, communications over a carrier may be organized according to TTIs or slots, each of which may include user data as well as control information or signaling to support decoding the user data. A carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc. ) and control signaling that coordinates operation for the carrier. In some examples (e.g., in a carrier aggregation configuration) , a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the system 100. For example, the carrier bandwidth may be one of a number of predetermined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz) . In some examples, each served UE 115 may be configured for operating over portions or all of the carrier bandwidth. In other examples, some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a predefined portion or range (e.g., set of subcarriers or RBs) within a carrier (e.g., “in-band” deployment of a narrowband protocol type) .

System 100 may support communication with a UE 115 on multiple cells or carriers, a feature which may be referred to as carrier aggregation (CA) or multi-carrier operation. A UE 115 may be configured with multiple downlink CCs and one or more uplink CCs according to a carrier aggregation configuration. Carrier aggregation may be used with both FDD and TDD component carriers. In some cases, system 100 may utilize enhanced component carriers (eCCs) . An eCC may be characterized by one or more features including wider carrier or frequency channel bandwidth, shorter symbol duration, shorter TTI duration, or modified control channel configuration. In some cases, an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have a suboptimal or non-ideal backhaul link) . An eCC may also be configured for use in unlicensed spectrum or shared spectrum (e.g., where more than one operator is allowed to use the spectrum) . An eCC characterized by wide carrier bandwidth may include one or more segments that may be utilized by UEs 115 that are not capable of monitoring the whole carrier bandwidth or are otherwise configured to use a limited carrier bandwidth (e.g., to conserve power) .

In some cases, an eCC may utilize a different symbol duration than other CCs, which may include use of a reduced symbol duration as compared with symbol durations of the other CCs. A shorter symbol duration may be associated with increased spacing between adjacent subcarriers. A device, such as a UE 115 or base station 105, utilizing eCCs may transmit wideband signals (e.g., according to frequency channel or carrier bandwidths of 20, 40, 60, 80 MHz, etc. ) at reduced symbol durations (e.g., 16.67 microseconds) . A TTI in eCC may consist of one or multiple symbol periods. In some cases, the TTI duration (that is, the number of symbol periods in a TTI) may be variable. Wireless communications systems such as an NR system may utilize any combination of licensed, shared, and unlicensed spectrum bands, among others. The flexibility of eCC symbol duration and subcarrier spacing may allow for the use of eCC across multiple spectrums. In some examples, NR shared spectrum may increase spectrum utilization and spectral efficiency, specifically through dynamic vertical (e.g., across frequency) and horizontal (e.g., across time) sharing of resources.

FIGs. 2A-2C illustrate aspects of group-based DCI in accordance with the present disclosure. FIG. 2A shows an exemplary aggregate control message 200 and G-DCI indicator 205. FIGs. 2B-2C show additional aspects of the exemplary G-DCI indicator 205 and aspects of a group-based DCI message 210 that may form part of the aggregate control message 200. The exemplary aggregate control message 200, G-DCI indicator 205, and group-based DCI messages 210 may be transmitted by base station 105 and received by a UE 115 in system 100.

As shown in FIG. 2A, G-DCI indicator 205 and aggregate control message 200 may be sent in a same slot, subframe, frame, or other transmission time interval such as may be used for communicating in system 100. In some aspects, transmission of the G-DCI indicator 205 may precede transmission of the aggregate control message 200. For instance, in some aspects, G-DCI indicator may be transmitted in subframe i and aggregate control message 200 may be transmitted in subframe i +1. G-DCI indicator 205 and aggregate control message may both be sent in the PDCCH, or the G-DCI indicator 205 may be utilize an indicator channel that is distinct from the PDCCH. G-DCI indicator 205 may signal the availability of aggregate control message 200. In one aspect, G-DCI indicator 205 is transmitted on preconfigured resources and can be located by UEs 115 without the need for blind decoding. In some aspects, Q-PSK modulation or other preconfigured modulation order may be used with G-DCI indicator 205.

As shown in FIG. 2B, exemplary G-DCI indicator 205 may include information for N group-based DCI messages 210 (Ctrl_1, …, Ctrl_N) , an indicator of the location of aggregate control message 200, and a CRC code. A total of B bits of information for each of the N group-based DCI messages may be provided, with R bits allocated to location. In one aspect, the B bits of information for each group-based DCI message 210 may include scheduling information. The scheduling information may provide an indication of the number or identity of UEs 115 in each of the N groups for which DCI is provided in the group-based DCI messages 210. The size of aggregate control message 200 may vary based on the number of users scheduled in each control group. In some cases, a fixed number K of UEs 115 can be scheduled in each group-based DCI message 210. K may be less than the number of UEs 115 associated with a particular control group. For example, each group-based DCI message 210 may schedule up to K=16 users in a particular control group, whereas an unlimited number of users may be associated with each control group.

The R bits of location information conveyed by G-DCI indicator 205 may provide a pointer to control channel resources of aggregate control message 200. In one aspect, the R bits may indicate a starting location of aggregate control message 200 and/or may signal locations of the constituent group-based DCI messages 210. In one aspect, aggregate control message 200 may be sent on consecutive control channel resources such as control channel elements (CCEs) , physical resource blocks (PRBs) , or other time-frequency units, and the R-bit location information may point to a starting resource location. For example, the R bits of location information may point to a starting CCE index of aggregate control message 200. In another example, the R bits of location information may indicate a starting location in the frequency domain and a number of symbols in the time domain for aggregate control message 200.

Based on the scheduling information and group-specific MCS assignments, UEs 115 may determine the starting location of their respective group-based control messages 210. For instance, a UE 115 associated with the third control group may determine an offset for its corresponding group-based DCI message (e.g., G-DCI_3) from the starting location of aggregate control message 200. The UE 115 may also determine a length of G-DCI_3 based on scheduling information from G-DCI indicator 205 and may thereby significantly reduce the need for blind decoding. In one aspect, use of preconfigured resources for the G-DCI indicator 205, the R-bit location information for aggregate control message 200, and scheduling information by which to determine a size of each of the N group-based DCI messages 210 enable UEs 115 to largely avoid blind decoding. An L-bit CRC code may be included to enable error detection in the decoding of the G-DCI indicator 205. Values of B, N, R, L and K may be configured by RRC signaling.

FIG. 2C shows additional aspects of exemplary group-based DCI messages 210 in accordance with the present disclosure. As shown, group-based DCI messages 210 may include common DCI (B1 bits) , user DCI 220, and a group CRC (B4 bits) . User DCI 220 may include short DCI (B2 bits) elements for up to K-M users with a user CRC (B5 bits) , and full DCI (B3 bits) elements for up to M users with a user CRC (B5 bits) . The length of each exemplary group-based DCI message 210 may be expressed as B1 + (K -M) *B2 + M *B3 + B4 bits.

The common DCI element of a group-based DCI message 210 may include DCI shared by all UEs that are scheduled with short DCI and may enable a reduction in the size of group-based DCI messages 210. Examples of common DCI may include an uplink/downlink scheduling indication for resource allocations, a modulation and coding scheme (MCS) for use with data channel transmissions, a new data indicator (NDI) for hybrid automatic repeat request (HARQ) operation, or other elements that may be common to multiple users in a same control group. In the present example, (K-M) users are scheduled with short DCI and may leverage the B1 bits of common DCI to derive their UE-specific DCI. The remaining M users may receive a full DCI message with B3 bits (B3 > B2) . Users with full DCI do not require use of the common DCI element thereby providing an additional degree of scheduling flexibility for the network. Finally, each element of user DCI 220 may include a user CRC having B5 bits. In one aspect, the user CRC is masked with a UE identifier such that user DCI 220 can be identified to particular device using a blind decoding process. To minimize overhead, a small-size user CRC may be utilized. In one specific example, B5 may total 5 bits in length, and the user CRC may be masked with a 5-bit unique identifier of the target UE such as an index value assigned to the UE as part of a group control configuration.

In one aspect, each group-based DCI message 210 also includes a group CRC (B4 bits) . The group CRC may facilitate decoding of the group-based DCI message 210 and may be masked with an identifier that is specific to a particular group of users. For example, a UE 115 may be associated with a particular control group, G-DCI_2, in the plurality of N control groups supported by G-DCI indicator 205. The UE 115 may be assigned to the G-DCI_2 group based on its channel conditions and may receive a configuration indicating a MCS and a group radio network temporary identifier (G-RNTI) used with group-based DCI messages 210 for G-DCI_2. The UE 115 may decode its group-based DCI message 210 using the configured G-RNTI and, if the group-based DCI message 210 is successfully decoded, it may perform blind decoding to detect user DCI 220 in one of the K locations where user DCI 220 can be scheduled. In this way, the UE 115 may find its group-based DCI message 210 in aggregate control message 200 and perform a limited number of checks to determine whether it has been sent user DCI. In addition to the G-RNTI, values of B1, B2, B3, B4, and B5 may be signaled via RRC messages or otherwise configured for UEs 115 that receive group-based DCI.

FIG. 3 shows a block diagram 300 of a wireless device 305 that supports group-based control transmissions in accordance with aspects of the present disclosure. Wireless device 305 may be an example of aspects of the user equipment 115 described with reference to FIG. 1. Wireless device 305 may include a receiver 310, a decoding manager 315, and a transmitter 320. Wireless device 305 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

Receiver 310 may be configured to receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, system information, configuration messages, etc. ) . For example, under the control of decoding manager 315, receiver 310 may receive slots or subframes having a control channel that supports group-based DCI transmissions for wireless device 305. Receiver 310 may pass such information on to other components of wireless device 305. For example, receiver 310 may pass information to decoding manager 315.

Receiver 310 may be an example of aspects of the transceiver 535 described with reference to FIG. 5. Decoding manager 315 may be an example of aspects of the decoding manager 415 described with reference to FIG. 4, or decoding manager 515 described with reference to FIG. 5.

Decoding manager 315 and/or at least some of its various sub-components 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 of the decoding manager 315 and/or at least some of its various sub-components may be executed by a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , an field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. In some examples, decoding manager 315 and/or at least some of its sub-components may be configured as a separate and distinct element in accordance with various aspects of the present disclosure. In other examples, decoding manager 315 and/or at least some of its various sub-components may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

Decoding manager 315 may determine a configuration of wireless device 305 for receiving group-based downlink control information. The configuration may include an identifier or index of a control group with which wireless device 305 is associated and a corresponding MCS used for control channel transmissions. As previously described, the control group assignment for wireless device 305 and the corresponding MCS used for control channel transmissions may be based on channel conditions. Users with similar channel conditions may be group together and an MCS that is appropriate to those channel conditions may be used for group-based DCI messages. In one aspect, QPSK modulation with a variable coding rate may be used such that group-based DCI messages associated with groups of users having relatively good channel conditions may use a low coding rate whereas group-based DCI messages associated with groups of users having relatively poor channel conditions may use higher coding rates. In one aspect, both the modulation and coding rate may differ for different control groups.

In one aspect, decoding manager 315 detects the availability of an aggregate control message in a control channel transmission. Detecting the availability of the aggregate control message may include both detecting that it is present in a particular slot or subframe as well as detecting that it may contain DCI for the control group to which wireless device 305 is associated. The aggregate control message may be detected by receiving a G-DCI indicator. The G-DCI indicator may be received in a same or different subframe as an aggregate control message. It may be received on control channel resources, or in a separate indicator channel. In some aspects, the G-DCI indicator signals a location of the aggregate control message in the control channel transmission avoiding the need to search for it.

Decoding manager 315 may be configured to determine a location of its group-based DCI message in the aggregate control message. In some aspects, the location of different control groups may be explicitly signaled by the G-DCI indicator. In other aspects, decoding manager 315 may utilize information from the G-DCI indicator and its configuration for receiving group-based downlink control information to determine a location of its group-based DCI message in a plurality of group-based DCI messages forming the aggregate control message. For example, decoding manager 315 may determine a starting CCE index of the aggregate control message based on the G-DCI indicator and may determine an offset from the starting CCE index to its group-based DCI message based on the number of groups and users that are scheduled for control channel transmission in the aggregate control message.

Decoding manager 315 may attempt to decode its group-based DCI message at the determined location. In some aspects, each control group may have a unique G-RNTI value and the CRC of each group-based DCI message may be scrambled or masked with its corresponding G-RNTI value. While it is not necessary to use different G-RNTI values, by doing so, a base station 105 main gain additional flexibility in control channel resource utilization. If the group-based DCI message is successfully decoded, decoding manager 315 may perform blind decoding on a plurality of decoding candidates to detect the availability of user-specific DCI. This may include blind decoding at a location corresponding to each DCI payload of the K scheduled users as shown in FIG. 2C. The user specific DCI may be scrambled or masked with a short identifier of the UE to facilitate detection and may yield short DCI or full DCI depending upon how the user is scheduled. Decoding manager 315 may combine short DCI with elements of common DCI to obtain a complete set of control information for wireless device. If the blind decoding of user locations in the group-based DCI message is not successful, decoding manager 315 may continue monitor for successive group-based control in a next slot or subframe. If user-specific DCI is obtained, then decoding manager 315 may coordinate with other elements of wireless device 305 to receive a data transmission from, or send a data transmission to, a serving base station 105.

Transmitter 320 may be configured to transmit signals generated by other components of wireless device 305. For example, transmitter 320 may send acknowledgement (ACK) /negative acknowledgement (NACK) signals in connection with reception of downlink transmissions, or it may send uplink data transmissions in accordance with a resource grant. The operation of transmitter 320 may be controlled by decoding manager 315. In some examples, the transmitter 320 may be collocated with a receiver 310 in a transceiver module. For example, the transmitter 320 may be an example of aspects of the transceiver 535 described with reference to FIG. 5. The transmitter 320 may include a single antenna, or it may include a set of antennas.

FIG. 4 shows a block diagram 400 of a wireless device 405 that supports group-based control transmissions in accordance with various aspects of the present disclosure. Wireless device 405 may be an example of aspects of a wireless device 305 or a user equipment 115 as described with reference to FIGs. 1 and 3. Wireless device 405 may include a receiver 410, a decoding manager 415, and a transmitter 420. Wireless device 405 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

Receiver 410 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, etc. ) . In one aspect, receiver 410 is configured to receive a device configuration via RRC configuration, control channel transmissions, a G-DCI indicator channel, system information, and other signaling from a base station and to pass such information on to other components of wireless device 405. Receiver 410 may be an example of aspects of the transceiver 535 described with reference to FIG. 5.

Decoding manager 415 may be an example of aspects of the decoding manager 315 or decoding manager 515 described with reference to FIGs. 3 and 5. As shown, decoding manager 415 may include a configuration component 425, an indicator component 430, and a decoding component 435.

Configuration component 425 may be configured to manage a configuration for receiving group-based control information. The configuration may be received from a base station 105 and may, in some aspects, include a control group configuration of wireless device 405. The control group configuration may identify a control group with which wireless device 405 is associated and a corresponding MCS used for sending group-based DCI messages on control channel resources. The control group configuration may also provide a G-RNTI that is used to scramble group-based DCI message and a user-specific identifier for blind decoding the group-based DCI message. The control group configuration may also provide an indicator and an MCS for other control groups which may be scheduled with a same aggregate control message.

The configuration for receiving group-based control information may also include a G-DCI indicator configuration. The G-DCI indicator configuration may include information for locating and interpreting the G-DCI indicator. In one aspect, the G-DCI indicator configuration identifies predetermined resources on which the G-DCI indicator is transmitted. In one aspect, the G-DCI indicator configuration indicates the number of control groups that are scheduled by the aggregate control message and a maximum number of users per control group. The G-DCI indicator configuration may indicate a number of bits allocated to each control group in the G-DCI indicator and their meaning. For example, as discussed in relation to FIGs. 2A-2C, B bits may be allocated for each of the N control groups in the G-DCI indicator and may convey the identity and/or number of users scheduled in a corresponding group DCI message. The G-DCI indicator configuration may also indicate how to locate the aggregate control message. In the example of FIGs. 2A-2C, R bits may be used to locate the aggregate control message and may be configured as a pointer to a starting time-frequency index of the aggregate control message, or as providing a starting frequency location of the aggregate control message and a number of symbols. The G-DCI indicator configuration may also define a CRC size for the G-DCI indicator.

The configuration for receiving group-based control information may also include a group DCI message configuration for wireless device 405. With information from the G-DCI indicator, the group DCI message configuration may enable a wireless device to determine a size of DCI for each control group. Referring to the example of FIGs. 2A-2C, the group DCI message configuration may indicate a size and meaning of common DCI information (e.g., B1 bits) , a size of short DCI messages (e.g., B2 bits) , a size of full DCI messages (e.g., B3 bits) , a number of full DCI payloads (e.g., full DCI for M users) , and a number of short DCI payloads (e.g., short DCI for K-M users) , etc. The group DCI message configuration may also specify a size of the group CRC (e.g., B4 bits) , and a size of the CRC used with DCI payloads (e.g., B5 bits) .

In one aspect, the various configuration elements managed by configuration component 425 may be received from a base station. For example, the configuration may be received via RRC signaling. In another aspect, portions of the configuration may be provisioned in wireless device 405 before it communicates with a base station. In still other aspects, configuration component 425 may determine some of the configuration for receiving group-based DCI from system information or broadcast messages.

Indicator component 430 may be configured to monitor for a G-DCI indicator in accordance with the configuration for receiving group-based control information of wireless device 405. In one aspect, indicator component 430 monitors predetermined resources of a control channel or indicator channel for a G-DCI indicator which may include some or all of the aspects described in connection with FIGs. 2A-2C. Based on information from the G-DCI indicator, indicator component 430 may determine a starting location of an aggregate control message and a size of its constituent group-based DCI messages. Indicator component 430 may also locate a first group-based DCI message associated with wireless device 405 based on information the G-DCI indicator and the related configuration. The aggregate control message may comprise a plurality of constituent group control messages (e.g., N group-based DCI messages corresponding to N control groups) . The plurality of group control messages may include at least the first group control message for wireless device 405 and a second group control message utilizing a different MCS. In some aspects, the indicator component 430 may determine a size of the group-based DCI messages based upon scheduling information obtained from the G-DCI indicator and a determination of their related modulation and coding. A starting location of the first group-based DCI message for wireless device 405 in the aggregate control message may be determined based on location information obtained from the G-DCI indicator and the size of the plurality of group-based DCI messages.

Decoding component 435 may be configured to decode a group-based DCI message identified by the indicator component 430. In one aspect, decoding component 435 may first decode the group-based DCI message and then attempt to decode UE-specific DCI. In some aspects, a location of the group-based DCI message may be provided by indicator component 430. Decoding component 435 may attempt to decode the group-based DCI message with error detection supported by a group CRC such as the B4-bit CRC discussed in connection with FIGs. 2A-2C. If decoding fails, decoding component 435 may discontinue further processing in the slot or subframe. If the group-based DCI message is successfully decoded, decoding component 435 may perform blind decoding on a plurality of decoding candidates in the group-based DCI message to detect whether any are scrambled with an identifier of wireless device 405. For example, referring to FIG. 2C, decoding component may identify the K possible locations for user DCI based on its group DCI message configuration and may attempt decoding using its UE-specific identifier. If it succeeds in decoding a short DCI payload, decoding manager 435 may also obtain common DCI elements to complete the UE-specific DCI. If it succeeds in decoding a full DCI payload, common DCI may not be needed. If the blind decoding fails, decoding component 435 may discontinue further processing.

Transmitter 420 may be configured to transmit signals generated by other components of wireless device 405. In one aspect, transmitter 420 may be configured to communicate with a base station based on a result of the decoding by decoding component 435. For instance, transmitter 420 may be configured to send ACK/NACK feedback to the base station in connection with downlink data reception on PDSCH resources assigned by the UE-specific DCI, or to transmit on uplink message on PUSCH resources granted by the UE-specific DCI.

Transmitter 420 may be collocated with receiver 410 in a transceiver module. In some aspects, transmitter 420 may form part of transceiver 535 as described with reference to FIG. 5. Transmitter 420 may include a single antenna, or it may include a set of antennas.

FIG. 5 shows a system 500 including a wireless device 505 that supports group-based DCI in accordance with various aspects of the present disclosure. Wireless device 505 may be an example of, or include the components of, a UE or wireless device as described above, e.g., with reference to FIGs. 1, 3, and 4. Wireless device 505 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including decoding manager 515, processor 520, memory 525, software 530, transceiver 535, antenna 540, and I/O controller 545. These components may be in electronic communication via one or more busses (e.g., bus 510) . Device 505 may communicate wirelessly with one or more base stations 105.

Processor 520 may include an intelligent hardware device, (e.g., a general-purpose processor, an application processor, a

aDSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, processor 520 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor 520. Processor 520 may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting control-free adaptive HARQ operation) .

Memory 525 may include RAM and ROM. The memory 525 may store computer-readable, computer-executable software 530 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 525 may contain, among other things, a BIOS which may control basic hardware and/or software operation such as the interaction with peripheral components or devices.

Software 530 may include code to implement aspects of the present disclosure, including code to support data channel search space operation. Software 530 may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software 530 may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

Transceiver 535 may form a communications interface of wireless device 505 and may be operative for bi-directional communication, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 535 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 535 may also include an RF front end to process a baseband signal and provide its output to the antennas 540 for transmission, and to similarly process packets received from the antennas.

In some cases, the wireless device 505 may include a single antenna 540. However, in some cases the wireless device 505 may have more than one antenna 540, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

I/O controller 545 may manage input and output signals for device 505. I/O controller 545 may also manage peripherals not integrated into wireless device 505. In some cases, I/O controller 545 may represent a physical connection or port to an external peripheral. In some cases, I/O controller 545 may utilize an operating system such as

or another known operating system. In other cases, I/O controller 545 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, I/O controller 545 may be implemented as part of a processor. In some cases, a user may interact with wireless device 505 via I/O controller 545 or via other hardware components controlled by I/O controller 545.

FIG. 6 shows a block diagram 600 of a wireless device 605 that supports group-based DCI in accordance with various aspects of the present disclosure. Wireless device 605 may be an example of aspects of a base station 105 as described with reference to FIG. 1. Wireless device 605 may include a receiver 610, a communications manager 615, and a transmitter 620. Wireless device 605 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

Receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, HARQ feedback, etc. ) . For example, receiver 610 may receive transmissions from wireless devices on PUCCH or PUSCH, including ACK/NACK signals responsive to the downlink transmissions of wireless device 605. Receiver 610 may pass such information on to other components of wireless device 605. Receiver 610 may be an example of aspects of transceiver 835 as described with reference to FIG. 8.

Transmitter 620 may transmit signals generated by other components of wireless device 605. For example, under the control of communications manager 615, transmitter 620 may transmit group-based DCI in downlink slots or subframes. In some examples, the transmitter 620 may be collocated with receiver 610 in a transceiver module. For example, the transmitter 620 may be an example of aspects of the transceiver 835 described with reference to FIG. 8. The transmitter 820 may include a single antenna, or it may include a set of antennas.

Communications manager 615 and/or at least some of its various sub-components 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 of the communications manager 615 and/or at least some of its various sub-components may be executed by a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , an field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. Communications manager 615 and/or at least some of its various sub-components may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical devices. In some examples, communications manager 615 and/or at least some of its various sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure. In other examples, communications manager 615 and/or at least some of its various sub-components may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. Communications manager 615 may be an example of aspects of the communications manager 715 described with reference to FIG. 7, or base station communications manager 815 described with reference to FIG. 8.

In one aspect, communications manager 615 may be configured to control operation of wireless device 605 to send control channel transmissions with group-based DCI to a plurality of UEs 115. In one aspect, communications manager 615 may associate a UE with a first group of UEs for receiving group-based DCI. Communications manager 616 may determine DCI for transmission to the UE in a first group control message associated with the first group of UEs. Communications manager 615 may cause transmitter 620 to send a first control message in a control channel transmission. The first control message may be an aggregate control message having a plurality of group control messages, including the first group control message. Each group control message in the plurality of group control messages may provide DCI for a plurality of UEs in an associated group of UEs.

In some aspects, the first group control message may include a group CRC to facilitate decoding by UEs in the first group of UEs. The DCI for transmission to the UE may be sent in one of a plurality of decoding candidates defined in the first group control message using an identifier of the UE. For example, communications manager 615 may choose a DCI payload location in the first control message for the user DCI, may generate a CRC for the user DCI, and may scramble it with an identifier of the UE so that it can be detected through blind decoding. In one aspect, communications manager 615 receives a communication from the UE in response to sending the first control message. For example, the user DCI may comprise an assignment of downlink resources, and the communication from the UE may comprise ACK/NACK feedback for a downlink data transmission. Alternatively, the user DCI may comprise a grant of uplink resources, and the communication from the UE may comprise an uplink data transmission on the granted resources.

FIG. 7 shows a block diagram 700 of a base station 705 that supports group-based DCI in accordance with various aspects of the present disclosure. Base station 705 may be an example of aspects of a wireless device 605, or a base station 105, as described with reference to FIGs. 1 and 6. Base station 705 may include a receiver 710, a communications manager 715, and a transmitter 720. Base station 705 may also include a processor. Each of these components may be coupled and configured to communicate with one another (e.g., via one or more buses) .

Receiver 710 may be configured to receive information such as packets, user data, or control information. This information may include uplink data transmissions, ACK/NACK feedback from user equipment devices indicating whether downlink transmissions from base station 705 were successfully received, etc. Receiver 710 may pass such information on to other components of base station 705 and may be an example of aspects of transceiver 835 described with reference to FIG. 8.

Transmitter 720 may transmit signals generated by other components of base station 705. For example, transmitter 720 may be configured to transmit an aggregate control message received from communications manager 715 in a designated slot or subframe. In some designs, the transmitter 720 may be collocated with a receiver 710 in a transceiver module. For instance, the transmitter 720 may be an example of aspects of the transceiver 835 described with reference to FIG. 8. The transmitter 720 may include a single antenna, or it may include a set of antennas.

Communications manager 715 may be an example of aspects of the communications manager 615 described with reference to FIG. 6. As shown, communications manager 715 includes a configuration component 725, an indicator component 730, and a group DCI component 735.

Configuration component 725 may configure wireless devices served by base station 705 to receive group-based DCI. In one aspect, configuration component 725 may associate users with control groups based on channel conditions. Users may be associated with control groups based on explicit channel reporting to base station 705 or based on channel conditions inferred by base station 705. In some aspects, group-based DCI for the different control groups may be sent on different numbers of control channel resources (e.g., CCE-based aggregation) .

Aggregation Level	Control Group
AL1	G-DCI_1
AL2	G-DCI_2
AL4	G-DCI_3, G-DCI_4

AL8	G-DCI_5
AL16	G-DCI_6

Table 1

Table 1 shows an example in which a first control group, G-DCI_1, may be configured to receive group-based DCI at aggregation level AL1, a second control group, G-DCI_2, may be configured to receive group-based DCI at aggregation level AL2, and so on. Each control group may also be configured with its own modulation and coding scheme (MSC) for group-based DCI. In one example, variable rate coding with QPSK modulation may be used for the different groups. Configuration component 725 may include information for each control group in the group-based DCI configuration provided by base station 705 to wireless devices. In one aspect, combined with information from the G-DCI indicator, the group-based DCI configuration may enable wireless devices to determine the length of each group-based DCI in an aggregate control message. In some aspects, the control group configuration may include a G-RNTI used to scramble group-based DCI messages and a user-specific identifier for blind decoding the group-based DCI message.

In one aspect, configuration component 725 may also provide a G-DCI indicator configuration. The G-DCI indicator configuration may include information for locating and interpreting the G-DCI indicator. In one aspect, the G-DCI indicator configuration identifies predetermined resources on which the G-DCI indicator is transmitted. In one aspect, the G-DCI indicator configuration indicates the number of control groups that are scheduled by the aggregate control message and a maximum number of users per control group. The G-DCI indicator configuration may indicate a number of bits allocated to each control group in the G-DCI indicator and their meaning. For example, as discussed with FIGs. 2A-2C, each of N control groups may be allocate B bits in the G-DCI indicator which may convey the identity and/or number of users scheduled in a corresponding group DCI message. The G-DCI indicator configuration may also indicate how to locate the aggregate control message. In the example of FIGs. 2A-2C, R bits may be used to locate the aggregate control message and may be configured as a pointer to a starting time-frequency index of the aggregate control message, or as providing a starting frequency location of the aggregate control message and a number of symbols. The G-DCI indicator configuration may also define a CRC size for the G-DCI indicator.

In one aspect, configuration component 725 may provide a group DCI message configuration for wireless device 705. With information from the G-DCI indicator, the group DCI message configuration may enable wireless device to determine a size of DCI for each scheduled group. Referring to the example of FIGs. 2A-2C, group DCI message configuration may indicate a size and meaning of common DCI information (e.g., B1 bits) , a size of short DCI messages (e.g., B2 bits) , a size of full DCI messages (e.g., B3 bits) , a number of full DCI payloads (e.g., full DCI for M users) , and a number of short DCI payloads (e.g., short DCI for K-M users) . The group DCI message configuration may also specify a size of the group CRC (e.g., B4 bits) , and a size of the CRC used with DCI payloads (e.g., B5 bits) .

In one aspect, the configuration for group based DCI may be signaled by base station 705 to wireless devices. For example, the configuration may be sent via RRC signaling. In another aspect, portions of the configuration may be provisioned in the wireless device before it communicates with a base station. In still other aspects, configuration component 725 may convey some of the configuration in system information or broadcast messages.

Indicator component 730 may be configured to generate a G-DCI indicator in accordance with the group-DCI configuration of configuration component 725. In one aspect, indicator component 730 determines resources of a control channel or indicator channel for sending the G-DCI indicator. The G-DCI indicator resources may preconfigured for wireless devices. In one aspect, the G-DCI indicator generated by indicator component 730 may include some or all of the aspects described in connection with FIGs. 2A-2C. Information conveyed by the G-DCI indicator may also identify a starting location of an aggregate control message and a size of its constituent group-based DCI messages. This information and the G-DCI indicator configuration may enable a wireless device to locate its group-based DCI message in an aggregate control message. For example, the aggregate control message may comprise a plurality of constituent group control messages (e.g., N group-based DCI messages corresponding to N user groups) . The plurality of group control messages may include at least a first group control message and a second group control message in relation to which a modulation and coding scheme (MCS) used with first group control message is different than a MCS used with the second group control message. In some aspects, the G-DCI indicator may include scheduling information for each of the plurality of group-based DCI messages. Based on the start of the location of the aggregate control message, the modulation and coding used with the group-based DCI messages, and a number of users scheduled in the group-based DCI messages, a wireless device may locate candidates for receiving DCI.

Group DCI component 735 may be configured to send an aggregate control message. In one aspect, group DCI component 735 may form a group-based DCI message for each control group. For example, the aggregate control message may include N group-based DCI messages. Each group-based DCI message may provide DCI to a variable number of users in a corresponding control group as configured by configuration component 725. In one aspect, group-based DCI messages convey DCI for up to K users in a control group. The DCI can be full DCI or it may be short DCI. Short DCI may have common DCI elements abstracted. Users scheduled with short DCI may utilize common DCI information in the group-based DCI message for the abstracted elements. Users scheduled with full DCI may not need to access the common DCI. Examples of common DCI may include an uplink/downlink scheduling indication, a MCS for use with data channel transmissions, a new data indicator (NDI) for HARQ operation, or any combination thereof. The availability of short DCI and full DCI payloads in the group-based DCI message may be configurable and may provide added scheduling flexibility for base station 705.

Within each group-based DCI message, each DCI payload may utilize a CRC that is scrambled with a unique identifier of the scheduled user. This CRC may be relatively short to reduce overhead and may complement a group CRC of the group-based DCI message. For example, group DCI component 735 may collect DCI for a control group and may determine up to K users for a control channel transmission. The K users may be assigned to corresponding short DCI and full DCI payloads of the group-based DCI message. Group DCI component 735 may prepare a small-size CRC for each DCI payload which may be masked with a UE-specific identifier. Common DCI may be added and a group CRC for the resulting group message may be calculated. In some aspects, the group CRC may be masked with a G-RNTI for additional flexibility. Group DCI component 735 may form an aggregate control message from the plurality of group-based DCI messages. The aggregate control message may then be sent by transmitter 720 on control channel resources identified by the G-DCI indicator. Group-based DCI message may occupy contiguous control channel resources.

The group-based DCI described herein may significantly increase the efficiency of control channel transmissions. As an example, consider a system with 200 total users hypothetically scheduling 80 users per slot. A configuration for group based control may include a total of 5 control groups (N=5) , a maximum of 16 users scheduled per group-based DCI message (K=16) , and 4 users receiving a full DCI (M=4) . The configuration may include 4 bits of common DCI (B1=4) , 32 bits for the full DCI payload (B3=32) , 28 bits for the short DCI payload (B2= (32-4) ) , and a 16-bit group CRC (B4=16) . The G-DCI indicator may use 4 bits of scheduling information per control group (B=4) , 8 bits of location information (R=8) , and a 16-bit CRC (L=16) . In this example, the length of a group-based DCI message scheduling the full K=16 users, would be B1+ (K-M) *B2+M*B3+B4 = 4+12*28+32*4+16= 484 bits. The length of the G-DCI indicator would be B*N+R+L = 4*5+8+16=44 bits. By comparison, control information utilizing a 24-bit CRC for sending 32-bit per-user DCI would require (32+24) *16 = 896 bits to serve the same 16 users. It can be seen that the present techniques represent a substantial improvement.

FIG. 8 shows a diagram of a system 800 including a wireless device 805 that supports group-based DCI in accordance with various aspects of the present disclosure. For example, wireless device 805 may be an example of, or include the components of, base station 105, wireless device 605, or base station 705 as described above, e.g., with reference to FIGs. 1, 6, and 7. Wireless device 805 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including base station communications manager 815, processor 820, memory 825, software 830, transceiver 835, antenna 840, network communications manager 845, and backhaul communications manager 850. These components may be in electronic communication via one or more busses (e.g., bus 810) . Wireless device 805 may communicate with one or more UEs 115.

Processor 820 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a central processing unit (CPU) , a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, processor 820 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor 820. Processor 820 may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting search space for a decoder) .

Memory 825 may include random access memory (RAM) and read only memory (ROM) . The memory 825 may store computer-readable, computer-executable software 830 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 825 may contain, among other things, a basic input/output system (BIOS) which may control basic hardware and/or software operation such as the interaction with peripheral components or devices.

Software 830 may include code to implement aspects of the present disclosure, including code to support search space for a decoder. Software 830 may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software 830 may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

Transceiver 835 may form a communications interface of wireless device 805 and be operative for bi-directional communication, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 835 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 835 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device 805 may include a single antenna 840. However, in some cases it may have more than one antenna 840, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

Network communications manager 845 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 845 may manage the transfer of data communications for client devices, such as one or more UEs 115.

Neighbor cell communications manager 850 may manage communications with other base stations 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the neighbor cell communications manager 850 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, neighbor cell communications manager 850 may provide an X2 interface within an Long Term Evolution (LTE) /LTE-A wireless communication network technology to provide communication between base stations 105.

FIG. 9 is a flowchart a method 900 of wireless communication utilizing group-based DCI in accordance with various aspects of the present disclosure. The operations of method 900 may be implemented by a user equipment 115, a

wireless device

305, 405, 505, or components thereof. For example, the operations of method 900 may be performed by a decoding manager as described with reference to FIGs. 3, 4, and 5. In some examples, a user equipment 115 or

wireless device

305, 405, 505 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the user equipment 115 or

wireless device

305, 405, 505 may perform aspects of the functions described below using special-purpose hardware.

At block 905, the user equipment may determine that it is associated with a first group of UEs for receiving group control messages from a base station. The association may be indicated in a device configuration received from the base station and may reflect channel conditions experienced by the UE in common with other members of its control group. The configuration may also indicate a MCS and aggregation level used for control channel transmissions to the first group of UEs. The operations of block 905 may be performed by a decoding manger and a receiver as described with reference to FIGs. 3-5.

At block 910, the UE may detect a first control message in a control channel transmission. The first control message may include a plurality of group control messages and each group control message may provide DCI for a plurality of UEs in an associated group of UEs including the first group of UEs. For example, the UE may monitor a control channel in accordance with its device configuration and may detect that an aggregate control message is transmitted in a particular slot or subframe. The operations of block 905 may be performed by a decoding manger and a receiver as described with reference to FIGs. 3-5.

At block 915, the UE may determine a location of a first group control message in the plurality of group control messages and, at block 920, the UE may decode the first group control message. For example, the UE may determine an offset from a starting location of the firs control message at which the first group control message can be found. It may attempt to decode the first group control message utilizing a group CRC. In some aspects, the group CRC may be scrambled with a G-RNTI configured for the first group of UEs. In certain examples, aspects of the operations of blocks 915-920 may be performed by a decoding manger and a receiver as described with reference to FIGs. 3-5.

At block 925, the UE may perform blind decoding on a plurality of decoding candidates in the first group control message to detect DCI. In some aspects, when the first group control message has been successfully decoded, the UE checks whether it contains DCI for the UE. For example, the UE may attempt to decode a plurality of DCI payloads in the first group message using a UE-specific identifier. If any of the payloads are successfully decoded, the UE obtains its DCI. The DCI may be short DCI or full DCI as described herein. In some aspects, the DCI includes a downlink assignment or an uplink grant. At block 925, the UE may communicate with the base station based at least in part on detecting the DCI. For instance, the UE may receive a downlink transmission on assigned resources or the UE may send an uplink transmission on granted resources. The downlink transmission may be a PDSCH transmission and the uplink transmission may be a PUSCH transmission. In certain examples, aspects of the operations of blocks 925-930 may be performed by a decoding manger, a receiver, and a transmitter as described with reference to FIGs. 3-5.

FIG. 10 is a flowchart illustrating a method 1000 of wireless communication utilizing group-based DCI in accordance with various aspects of the present disclosure. The operations of method 1000 may be performed by a base station 105 or its components as described herein. In one aspect, the operations of method 1000 may be performed by a communications manager as described with reference to FIGs. 6-8. In some examples, a base station 105 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may perform aspects of the functions described below using special-purpose hardware.

At block 1005, the base station may associate a UE with a first group of UEs for receiving group control messages from the base station. The association may be indicated in a device configuration sent to the UE and may reflect channel conditions experienced by the UE in common with other members of its control group. In certain examples, aspects of the operations of block 1005 may be performed by a communication manager and a transmitter as described with reference to FIGs. 6-8.

At block 1010, the base station may determine DCI for transmission to the UE in a first group control message associated with the first group of UEs. For example, the base station may determine to send DCI to users in a control group and may prepare a corresponding group-based DCI message. At block 1015, the base station may send a first control message in a control channel transmission. The first control message may include a plurality of group control messages, including the first control message, and each group control message may provide DCI for a plurality of UEs in an associated group of UEs. The first group control message may include a group CRC to facilitate decoding by UEs in the first group of UEs. DCI for the UE may be sent in one of a plurality of decoding candidates defined in the first group control message using an identifier of the UE. In certain examples, aspects of the operations of blocks 1010-1015 may be performed by a communication manager and a transmitter as described with reference to FIGs. 6-8.

At block 1015, the base station may receive a communication from the UE in response to sending the first control message. For example, the DCI may include a downlink assignment on a PDSCH, or an uplink grant on a PUSCH. The base station may receive ACK/NACK feedback for a scheduled PDSCH transmission conveyed by the first control message, or an uplink transmission on PUSCH on resources granted by DCI conveyed by the first control message. In certain examples, aspects of the operations of block 1005 may be performed by a communication manager and a receiver as described with reference to FIGs. 6-8.

It should be noted that the methods described above describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Furthermore, aspects from two or more of the methods may be combined.

Techniques described herein may be used for various wireless communications systems such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , single carrier frequency division multiple access (SC-FDMA) , and other systems. The terms “system” and “network” are often used interchangeably. A code division multiple access (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 may be 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 time division multiple access (TDMA) system may implement a radio technology such as Global System for Mobile Communications (GSM) .

An orthogonal frequency division multiple access (OFDMA) system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications system (UMTS) . 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are releases of Universal Mobile Telecommunications System (UMTS) that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, NR, and Global System for Mobile communications (GSM) are described in documents from the 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. While aspects an LTE or an NR system may be described for purposes of example, and LTE or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE or NR applications.

In LTE/LTE-A networks, including such networks described herein, the term evolved node B (eNB) may be generally used to describe the base stations. The wireless communications system or systems described herein may include a heterogeneous LTE/LTE-A or NR network in which different types of evolved node B (eNBs) provide coverage for various geographical regions. For example, each eNB, gNB or base station may provide communication coverage for a macro cell, a small cell, or other types of cell. The term “cell” may be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g., sector, etc. ) of a carrier or base station, depending on context.

Base stations may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, eNodeB (eNB) , next generation NodeB (gNB) , Home NodeB, a Home eNodeB, or some other suitable terminology. The geographic coverage area for a base station may be divided into sectors making up only a portion of the coverage area. The wireless communications system or systems described herein may include base stations of different types (e.g., macro or small cell base stations) . The UEs described herein may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like. There may be overlapping geographic coverage areas for different technologies.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell is a lower-powered base station, as compared with a macro cell, that may operate in the same or different (e.g., licensed, unlicensed, etc. ) frequency bands as macro cells. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell, for example, may cover a small geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) . An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells (e.g., component carriers) .

The wireless communications system or systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

The downlink transmissions described herein may also be called forward link transmissions while the uplink transmissions may also be called reverse link transmissions. Each communication link described herein-including, for example, wireless communications system 100 of FIG. 1-may include one or more carriers, where each carrier may be a signal made up of multiple sub-carriers (e.g., waveform signals of different frequencies) .

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “exemplary” used herein 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 devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

Information and signals described herein 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, or any combination thereof.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A 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 computer-readable medium. Other examples and implementations are within the scope 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 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 (for example, a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive 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) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an exemplary step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory 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, non-transitory computer-readable media may comprise RAM, ROM, electrically erasable programmable read only memory (EEPROM) , compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory 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, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include 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 description herein 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 generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A method of wireless communication performed by a user equipment (UE) , comprising:

determining that the UE is associated with a first group of UEs for receiving group control messages from a base station;

detecting a first control message in a control channel transmission, the first control message comprising a plurality of group control messages, wherein each group control message in the plurality of group control messages provides downlink control information (DCI) for a plurality of UEs in an associated group of UEs including the first group of UEs;

determining a location of a first group control message in the plurality of group control messages, wherein the first group control message provides DCI for the first group of UEs;

decoding the first group control message;

performing blind decoding on a plurality of decoding candidates in the first group control message to detect DCI for the UE; and

communicating with the base station based at least in part on the detected DCI for the UE.
The method of claim 1, further comprising:

receiving, from the base station, a second control message comprising an indication of the availability of the first control message in the control channel transmission, and wherein detecting the first control message is based at least in part on the second control message.
The method of claim 2, wherein the second control message comprises scheduling information for the plurality of group control messages in the first control message.
The method of claim 3, wherein the scheduling information comprises an indication of a number of UEs scheduled for DCI transmission in each of the plurality of group control messages.
The method of claim 2, wherein the second control message is received on predetermined time-frequency resources.
The method of claim 2 wherein the second control message comprises a pointer to a starting location of the first control message in the control channel transmission.
The method of claim 3, wherein determining the location of the first group control message is based at least in part on the scheduling information and a starting location message of the first control message.
The method of claim 1, wherein the plurality of group control messages comprises at least the first group control message and a second group control message, and wherein a modulation and coding scheme (MCS) used with the first group control message is different than a MCS used with the second group control message.
The method of claim 1, wherein performing blind decoding comprises detecting that a decoding candidate in the plurality of decoding candidates of the first group control message is scrambled with an identifier of the UE.
The method of claim 1, wherein at least a portion of the DCI in the first group control message is common DCI that is shared by UEs of the first group of UEs.
The method of claim 10, wherein the common DCI comprises an uplink/downlink scheduling indication, a modulation and coding scheme (MCS) for use with data channel transmissions, a new data indicator (NDI) for hybrid automatic repeat request (HARQ) operation, or any combination thereof.
The method of claim 1, further comprising:

receiving, from the base station, a configuration indicating that the UE is associated with the first group of UEs, and wherein the configuration comprises at least one of a number of the plurality of group control messages, a maximum number of scheduled users per group control message, an indication of a modulation and coding scheme (MCS) used with each group control message in the plurality of group control messages, an indication of common DCI that is used in common for a same group control message, an indication of a number of UEs sharing the common DCI, or any combination thereof.
A method of wireless communication performed by a base station, comprising:

associating a user equipment (UE) with a first group of UEs for receiving group control messages from the base station;

determining downlink control information (DCI) for transmission to the UE in a first group control message associated with the first group of UEs;

sending a first control message in a control channel transmission, the first control message comprising a plurality of group control messages, including the first group control message, wherein each group control message in the plurality of group control messages provides DCI for a plurality of UEs in an associated group of UEs,

wherein the first group control message comprises a group cyclic redundancy check (CRC) to facilitate decoding by UEs in the first group of UEs, and

wherein the DCI for transmission to the UE is sent in one of a plurality of decoding candidates defined in the first group control message using an identifier of the UE; and

receiving a communication from the UE in response to the first control message.
The method of claim 13, further comprising:

sending a second control message comprising an indication of the availability of the first control message in the control channel transmission.
The method of claim 14, wherein the second control message is sent on predetermined time-frequency resources.
The method of claim 14, wherein the second control message indicates a location of the first control message in the control channel transmission.
The method of claim 14, wherein the second control message comprises scheduling information for the plurality of group control messages in the first control message.
The method of claim 17, wherein the scheduling information comprises an indication of a number of UEs scheduled for DCI transmission in each of the plurality of group control messages.
The method of claim 13, wherein the plurality of group control messages comprises at least the first group control message and a second group control message, and wherein a modulation and coding scheme (MCS) used with the first group control message is different than a MCS used with the second group control message.
The method of claim 13, wherein each of the plurality of group control messages is associated with a corresponding plurality of UEs based at least in part on channel conditions.
The method of claim 14, wherein at least a portion of the DCI in the first group control message is common DCI that is shared by UEs of the first group of UEs.
The method of claim 21, wherein the common DCI comprises at least an uplink/downlink scheduling indication, a modulation and coding scheme (MCS) for use with data channel transmissions, a new data indicator (NDI) for hybrid automatic repeat request (HARQ) operation, or any combination thereof.
The method of claim 13, further comprising:

transmitting, to the UE, a configuration indicating that the UE is associated with the first group of UEs, and wherein the configuration comprises at least one of a number of the plurality of group control messages, a maximum number of scheduled users per group control message, an indication of a modulation and coding scheme (MCS) used with each group control message in the plurality of group control messages, an indication of common DCI that is used in common for a same group control message, an indication of a number of UEs sharing the common DCI, or any combination thereof.
A user equipment (UE) , comprising:

means for determining that the UE is associated with a first group of UEs for receiving group control messages from a base station;

means for detecting a first control message in a control channel transmission, the first control message comprising a plurality of group control messages, wherein each group control message in the plurality of group control messages provides downlink control information (DCI) for a plurality of UEs in an associated group of UEs including the first group of UEs;

means for determining a location of a first group control message in the plurality of group control messages, wherein the first group control message provides DCI for the first group of UEs;

means for decoding the first group control message;

means for performing blind decoding on a plurality of decoding candidates in the first group control message to detect DCI for the UE; and

means for communicating with the base station based at least in part on the detected DCI for the UE.
The user equipment of claim 24, further comprising:

means for receiving, from the base station, a second control message comprising an indication of the availability of the first control message in the control channel transmission, and wherein detecting the first control message is based at least in part on the second control message.
The user equipment of claim 25, wherein the second control message comprises scheduling information for the plurality of group control messages in the first control message.
The user equipment of claim 26, wherein the scheduling information comprises an indication of a number of UEs scheduled for DCI transmission in each of the plurality of group control messages.
The user equipment of claim 24, wherein the plurality of group control messages comprises at least the first group control message and a second group control message, and wherein a modulation and coding scheme (MCS) used with the first group control message is different than a MCS used with the second group control message.
The user equipment of claim 24, wherein at least a portion of the DCI in the first group control message is common DCI that is shared by UEs of the first group of UEs.
The user equipment of claim 29, wherein the common DCI comprises an uplink/downlink scheduling indication, a modulation and coding scheme (MCS) for use with data channel transmissions, a new data indicator (NDI) for hybrid automatic repeat request (HARQ) operation, or any combination thereof.
A base station, comprising:

means for associating a user equipment (UE) with a first group of UEs for receiving group control messages;

means for determining downlink control information (DCI) for transmission to the UE in a first group control message associated with the first group of UEs;

means for sending a first control message in a control channel transmission, the first control message comprising a plurality of group control messages, including the first group control message, wherein each group control message in the plurality of group control messages provides DCI for a plurality of UEs in an associated group of UEs,

wherein the first group control message comprises a group cyclic redundancy check (CRC) to facilitate decoding by UEs in the first group of UEs, and

wherein the DCI for transmission to the UE is sent in one of a plurality of decoding candidates defined in the first group control message using an identifier of the UE; and

means for receiving a communication from the UE in response to the first control message.
The base station of claim 31, wherein the means for sending comprise means for sending a second control message that indicates a location of the first control message in the control channel transmission.
The base station of claim 32, wherein the second control message comprises scheduling information for the plurality of group control messages in the first control message.
The base station of claim 33, wherein the scheduling information comprises an indication of a number of UEs scheduled for DCI transmission in each of the plurality of group control messages.
The base station of claim 31, wherein the plurality of group control messages comprises at least the first group control message and a second group control message, and wherein a modulation and coding scheme (MCS) used with the first group control message is different than a MCS used with the second group control message.
A user equipment (UE) , comprising:

a processor;

memory coupled with the processor; and

instructions stored in the memory and operable, when executed by the processor, to:

determine that the UE is associated with a first group of UEs for receiving group control messages from a base station;

detect a first control message in a control channel transmission, the first control message comprising a plurality of group control messages, wherein each group control message in the plurality of group control messages provides downlink control information (DCI) for a plurality of UEs in an associated group of UEs including the first group of UEs;

determine a location of a first group control message in the plurality of group control messages, wherein the first group control message provides DCI for the first group of UEs;

decode the first group control message;

perform blind decoding on a plurality of decoding candidates in the first group control message to detect DCI for the UE; and

communicate with the base station based at least in part on the detected DCI for the UE.
The user equipment of claim 36, wherein the instructions are further operable, when executed by the processor, to receive, from the base station, a second control message comprising an indication of the availability of the first control message in the control channel transmission, and wherein detecting the first control message is based at least in part on the second control message.
The user equipment of claim 37, wherein the second control message comprises scheduling information for the plurality of group control messages in the first control message.
The user equipment of claim 38, wherein the scheduling information comprises an indication of a number of UEs scheduled for DCI transmission in each of the plurality of group control messages.
The user equipment of claim 36, wherein the plurality of group control messages comprises at least the first group control message and a second group control message, and wherein a modulation and coding scheme (MCS) used with the first group control message is different than a MCS used with the second group control message.
The user equipment of claim 36 wherein at least a portion of the DCI in the first group control message is common DCI that is shared by UEs of the first group of UEs.
The user equipment of claim 41, wherein the common DCI comprises an uplink/downlink scheduling indication, a modulation and coding scheme (MCS) for use with data channel transmissions, a new data indicator (NDI) for hybrid automatic repeat request (HARQ) operation, or any combination thereof.
A base station, comprising:

a processor;

memory coupled with the processor; and

instructions stored in the memory and operable, when executed by the processor, to:

associate a user equipment (UE) with a first group of UEs for receiving group control messages from the base station;

determine downlink control information (DCI) for transmission to the UE in a first group control message associated with the first group of UEs;

send a first control message in a control channel transmission, the first control message comprising a plurality of group control messages, including the first group control message, wherein each group control message in the plurality of group control messages provides DCI for a plurality of UEs in an associated group of UEs,

wherein the first group control message comprises a group cyclic redundancy check (CRC) to facilitate decoding by UEs in the first group of UEs, and

wherein the DCI for transmission to the UE is sent in one of a plurality of decoding candidates defined in the first group control message using an identifier of the UE; and

receive a communication from the UE in response to the first control message.
The base station of claim 43, wherein the instructions are further operable, when executed by the processor, to send a second control message that indicates a location of the first control message in the control channel transmission.
The base station of claim 44, wherein the second control message comprises scheduling information for the plurality of group control messages in the first control message.
The base station of claim 45, wherein the scheduling information comprises an indication of a number of UEs scheduled for DCI transmission in each of the plurality of group control messages.
The base station of claim 43, wherein the plurality of group control messages comprises at least the first group control message and a second group control message, and wherein a modulation and coding scheme (MCS) used with the first group control message is different than a MCS used with the second group control message.
A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable by a processor of a user equipment (UE) to:

determine that the UE is associated with a first group of UEs for receiving group control messages from a base station;

detect a first control message in a control channel transmission, the first control message comprising a plurality of group control messages, wherein each group control message in the plurality of group control messages provides downlink control information (DCI) for a plurality of UEs in an associated group of UEs including the first group of UEs;

determine a location of a first group control message in the plurality of group control messages, wherein the first group control message provides DCI for the first group of UEs;

decode the first group control message;

perform blind decoding on a plurality of decoding candidates in the first group control message to detect DCI for the UE; and

communicate with the base station based at least in part on the detected DCI for the UE.
A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable by a processor of a base station to:

associate a user equipment (UE) with a first group of UEs for receiving group control messages from the base station;

determine downlink control information (DCI) for transmission to the UE in a first group control message associated with the first group of UEs;

send a first control message in a control channel transmission, the first control message comprising a plurality of group control messages, including the first group control message, wherein each group control message in the plurality of group control messages provides DCI for a plurality of UEs in an associated group of UEs,

wherein the first group control message comprises a group cyclic redundancy check (CRC) to facilitate decoding by UEs in the first group of UEs, and

wherein the DCI for transmission to the UE is sent in one of a plurality of decoding candidates defined in the first group control message using an identifier of the UE; and

receive a communication from the UE in response the first control message.