Patent Description:
In Third Generation Partnership Project (3GPP) New Radio (NR), also referred to as "<NUM>", a slot may be defined to be <NUM> symbols and a subframe may be <NUM> millisecond (ms). The length of a subframe may hence be as in Long Term Evolution (LTE); however, depending of numerology the number of slots per subframe can vary in NR. On carrier frequencies below <NUM> the numerologies <NUM> and <NUM> Sub-Carrier Spacing (SCS) can be supported while <NUM> SCS may be optional for a wireless device (WD), such as a user equipment (UE). The <NUM> SCS may be equal to the LTE numerology for normal cyclic prefix.

Downlink control information (DCI) is transmitted over a Physical Downlink Control Channel (PDCCH) and is blindly searched for by the WD. The search performed by the WD may involve one or more decoding attempts that are performed based on a hypothetical PDCCH located in pre-defined time-frequency locations, called search space entry. The set of time-frequency locations where a PDCCH may be received may be called a search space. In NR, the region of frequency resources within a slot wherein the search space is defined can be called Control Region Set (CORESET) and can be configured very flexibly. A WD can have several CORESETs configured. The search space for a CORESET may further include multiple time-locations where PDCCH is monitored.

NR may further support two types of transmissions, Type A and Type B. Type A transmissions may be slot-based, where a slot is defined as <NUM> orthogonal frequency division multiplexed (OFDM) symbols, while Type B is non-slot-based. The purpose of Type B may be to enable making short transmissions that can start and end more flexibly than Type A. Mini-slot transmissions can be dynamically scheduled and in 3GPP Release <NUM> (Rel-<NUM>). For example, mini-slots may:.

Although NR can support flexible starts and ends of mini-slot transmissions it may be convenient from a scheduling perspective to define transmission time intervals (TTIs) and keep transmissions within a TTI. For the DL, i.e., network node to wireless device, it may be convenient to define PDCCH monitoring occasions at regular time instances and to keep DL transmissions between two consecutive monitoring occasions.

Type B transmissions may reduce latency for Ultra-Reliable Low-Latency Communication (URLLC). The transmissions can be scheduled and start sooner than for slot-based transmissions where scheduling and transmissions wait until the next slot.

NR can support two types of configured grants, Type <NUM> and Type <NUM>. For Type <NUM>, the WD may be radio resource control (RRC) configured with a grant that indicates the required transmission parameters; while for Type <NUM> the configured grant may be partly RRC configured and partly L1 signaled (e.g., DCI signaling). For a Type <NUM> configured grant, the resource allocation may follow an UL, i.e., from the wireless device to the network node, grant received on the DCI and the resource then recurs periodically, where the period is configured by RRC. The UL grant may have a time domain resource assignment field that provides a row index of a higher layer configured table e.g., pusch-symbolAllocation, where the indexed row defines the slot offset K2, the start and length indicator SLIV, and the physical uplink shared channel (PUSCH) mapping type to be applied in the PUSCH transmission. The WD may transmit a Medium Access Control-Control Element (MAC-CE) confirm message when the configured grant is activated or deactivated.

A configured grant can use one or more Hybrid Automatic Repeat reQuest (HARQ) processes. In the configuration of the configured grant the number of HARQ processes may be specified as well as a configuredGrantTime, which can take values of one or more periods P. The HARQ process ID may be determined by for example 3GPP Technical Specification (TS) <NUM>, v15. <NUM>, Section <NUM>. <NUM>, as follows:.

To improve reliability in uplink transmissions, HARQ-based retransmission may be a useful solution, if latency requirements allow for retransmission.

In NR 3GPP Rel-<NUM> (with implicit HARQ ACK/NACK), it may be specified in the MAC spec that the WD starts a timer when a MAC protocol data unit (PDU) is sent on the configured grant and flushes the buffer for new data when that timer expires. In other words, the WD may assume an implicit HARQ ACK after the timer expires. A dynamic grant for retransmission can be sent before the timer expires. This retransmission grant may effectively serve as an HARQ NACK.

The RRC ConfiguredGrantConfig information element is defined in 3GPP TS <NUM>, as shown below according to 3GPP TS <NUM>, version <NUM>.

However, there may be problems with implicit HARQ acknowledgements, where, for example, the WD may not be able to determine which of at least two cases is occurring, e.g., whether a lack of HARQ feedback from the network node indicates an implicit HARQ ACK or whether the network node is unaware that an UL transmission was even sent by the WD.

3GPP document with a title "Discussion on evaluation methodology for reliability" defines that before decoding PUSCH at gNB, the gNB has to detect PUSCH transmission by detecting DMRS or energy of PUSCH transmission.

The invention is defined by a method implemented in a network node according to claim <NUM>, a method implemented in a wireless device according to claim <NUM>, a network node according to claim <NUM> and a wireless device according to claim <NUM>. Further details are defined by claims <NUM>, <NUM> and <NUM>-<NUM>.

In some embodiments, a configured grant occurs periodically, and therefore, it may not be efficient for MAC to send a packet if the buffer is empty. Thus, a skip uplink transmission mechanism may be used, that may advantageously save energy and/or reduce interference.

However, this can lead to an error case that might be relevant for fulfilling a very demanding Ultra-reliable Low Latency Communication (URLLC) requirement, such as <NUM>-<NUM>. One problem is that the WD may not be able to distinguish between two cases, since in both cases the WD does not receive any response from the network node (e.g., gNB). The two cases may be as follows:.

If an explicit HARQ feedback (or more precisely, HARQ ACK is needed since HARQ NACK is already implicitly defined via the re-transmission DL grant) is introduced, then it can increase resource usage of the DL DCI. Since the target Block Error Rate (BLER) for URLLC is <NUM>-<NUM>-<NUM>-<NUM>, most of the transmissions are successful and introducing explicit HARQ ACK can introduce a high signaling load. For example, for BLER=<NUM>-<NUM>, after <NUM>,<NUM> transport block (TB) transmissions, an average network node may send <NUM>,<NUM> HARQ-ACK but only one NACK. Instead of transmitting HARQ-ACK, which is for Case <NUM>, some embodiments of this disclosure propose sending a signal for Case <NUM>, which could have lower occurrence and therefore a lower signaling load than HARQ ACK.

Some embodiments introduce a new downlink control signaling arrangement, which may be called energy_detection_indicator, and which can be transmitted to the WD for a configured grant transmission. The energy_detection_indicator may be one bit of information which comes out of the energy-detection process over the assigned resources for an uplink's configured grant transmission. In one example, the signaling is sent to the WD through the next available DCI. In another example, the signaling is sent where a separate/common physical downlink shared channel (PDSCH) resource can be allocated for the signaling transmission. In some embodiments, the techniques in this disclosure allow the energy_detection_indicator to be sent occasionally, only when the detected energy is less than a pre-defined threshold. This occasional transmission can reduce the load of the added signaling as compared to existing techniques. Accordingly, some embodiments of this disclosure may improve the reliability of uplink configured grant transmissions.

Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to an energy detection indicator. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

The term "network node" used herein can be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio node such as MSRBS, multi-cell/multicast coordination entity (MCE), relay node, integrated access and backhaul (IAB) node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment. The term "radio node" used herein may be used to also denote a wireless device (WD) such as a wireless device (WD) or a radio network node.

It can be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell/multicast Coordination Entity (MCE), relay node, IAB node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH).

Even though the descriptions herein may be explained in the context of one of a Downlink (DL) and an Uplink (UL) communication, it should be understood that the basic principles disclosed may also be applicable to the other of the one of the DL and the UL communication. In some embodiments in this disclosure, the principles may be considered applicable to a transmitter and a receiver using HARQ feedback schemes/mechanisms.

Any two or more embodiments described in this disclosure may be combined in any way with each other.

The term "resource", as used herein, is intended to be interpreted in a general way. It may indicate an arbitrary or predetermined combination of subcarriers, time slots, mini-slots, symbols, codes and/or spatial dimensions.

The allocation/assignment of radio resources to the at least one wireless device for communications may be interpreted as the set of resources for use for the at least one wireless device, that have been configured, e.g., preconfigured, by the network node. The radio resources comprised in the allocation/assignment may be referred to herein as the assigned resources to the at least one wireless device. In some embodiments, the assigned resources are configured by higher layers, such as RRC, for UL transmissions. In other embodiments, the assigned resources may the assigned or configured in other ways.

In some embodiments, energy detection may include detecting power-related or energy-related or amplitude-related or phase-related or signal strength-related aspects of a signal or resources.

In some embodiments, information on one or more resources may be considered to be transmitted in a message having a specific format. A message may comprise or represent bits representing payload information and coding bits, e.g., for error coding.

In some embodiments, receiving (or obtaining) information may comprise receiving one or more information messages (e.g., energy detection indictor or re-transmission). It may be considered that receiving signaling or messages comprises demodulating and/or decoding and/or detecting one or more messages, in particular a message carried by the signaling, e.g. based on an assumed set of resources, which may be searched and/or listened for. It may be assumed that both sides of the communication are aware of the configurations, and may determine the set of resources. In some embodiments, energy detection may be performed e.g., by network node even before demodulation and/or decoding a potential message is attempted.

An indication (e.g., an energy detection indication etc.) generally may explicitly and/or implicitly indicate the information it represents and/or indicates. Implicit indication may for example be based on position and/or resource used for transmission. Explicit indication may for example be based on a parametrization with one or more parameters, and/or one or more index or indices corresponding to a table, and/or one or more bit patterns representing the information.

Referring now to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in <FIG> a schematic diagram of a communication system <NUM>, according to an embodiment, such as a 3GPP-type cellular network that may support standards such as LTE and/or NR (<NUM>), which comprises an access network <NUM>, such as a radio access network, and a core network <NUM>. The access network <NUM> comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes <NUM>), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas <NUM>). Each network node 16a, 16b, 16c is connectable to the core network <NUM> over a wired or wireless connection <NUM>. A first wireless device (WD) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of WDs 22a, 22b (collectively referred to as wireless devices <NUM>) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node <NUM>. Note that although only two WDs <NUM> and three network nodes <NUM> are shown for convenience, the communication system may include many more WDs <NUM> and network nodes <NUM>.

A network node <NUM> is configured to include an energy detection unit <NUM> which is configured to perform energy detection on assigned resources corresponding to a configured uplink grant. In some embodiments, the energy detection unit <NUM> may be configured to, based on a level of the detected energy, one of: send an energy detection indication corresponding to the assigned resources associated with the configured uplink grant; and demodulate and decode a transport block associated with the configured uplink grant.

A wireless device <NUM> is configured to include a re-transmission determination unit <NUM> which is configured to receive an energy detection indication corresponding to assigned resources associated with a configured uplink grant; and determine whether to perform an UL re-transmission based at least in part on the energy detection indication.

The host application <NUM> may be operable to provide a service to a remote user, such as a WD <NUM> connecting via an OTT connection <NUM> terminating at the WD <NUM> and the host computer <NUM>. The "user data" may be data and information described herein as implementing the described functionality. In one embodiment, the host computer <NUM> may be configured for providing control and functionality to a service provider and may be operated by the service provider or on behalf of the service provider. The processing circuitry <NUM> of the host computer <NUM> may enable the host computer <NUM> to observe, monitor, control, transmit to and/or receive from the network node <NUM> and/or the wireless device <NUM>. The processing circuitry <NUM> of the host computer <NUM> may include a monitor unit <NUM> configured to enable the service provider to observe, monitor, control, transmit to and/or receive from the network node <NUM> and/or the wireless device <NUM>.

Thus, the network node <NUM> further has software <NUM> stored internally in, for example, memory <NUM>, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node <NUM> via an external connection. The processing circuitry <NUM> may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by network node <NUM>. Processor <NUM> corresponds to one or more processors <NUM> for performing network node <NUM> functions described herein. The memory <NUM> is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software <NUM> may include instructions that, when executed by the processor <NUM> and/or processing circuitry <NUM>, causes the processor <NUM> and/or processing circuitry <NUM> to perform the processes described herein with respect to network node <NUM>, such as the process described with reference to the flowchart in <FIG> and other figures. For example, processing circuitry <NUM> of the network node <NUM> may include energy detection unit <NUM> configured to perform energy detection on assigned resources corresponding to a configured uplink grant.

In some embodiments, the processing circuitry <NUM> and/or the energy detection unit <NUM> is further configured to communication an indication of a level of the detected energy to the wireless device as part of a HARQ feedback scheme. In some embodiments, the processing circuitry <NUM> and/or the energy detection unit <NUM> is further configured to at least one of: determine whether the detected energy is less than or equal to a pre-defined threshold value; determine whether or not to communicate an indication of a level of the detected energy based on whether the detected energy is less than or equal to the pre-defined threshold value; and determine whether or not to demodulate and decode an uplink transmission on the assigned resources based on the level of the detected energy. In some embodiments, the processing circuitry <NUM> and/or the energy detection unit <NUM> is further configured to communication an indication of a level of the detected energy in a downlink control information (DCI) message. In some embodiments, the processing circuitry <NUM> and/or the energy detection unit <NUM> is further configured to perform the energy detection by being configured to perform a demodulation reference signal (DMRS) sequence detection.

The processing circuitry <NUM> may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by WD <NUM>. The processor <NUM> corresponds to one or more processors <NUM> for performing WD <NUM> functions described herein. The WD <NUM> includes memory <NUM> that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software <NUM> and/or the client application <NUM> may include instructions that, when executed by the processor <NUM> and/or processing circuitry <NUM>, causes the processor <NUM> and/or processing circuitry <NUM> to perform the processes described herein with respect to WD <NUM>, such as the process described with reference to the flowchart in <FIG> and other figures. For example, the processing circuitry <NUM> of the wireless device <NUM> may include a re-transmission determination unit <NUM> configured to receive an energy detection indication corresponding to assigned resources associated with a configured uplink grant; and determine whether to perform an uplink (UL) re-transmission based at least in part on the energy detection indication.

In some embodiments, the energy detection indication indicates a level of energy detected by the network node <NUM> on the assigned resources as part of a HARQ feedback scheme. In some embodiments, the energy detection indication is received in a downlink control information (DCI) message. In some embodiments, the processing circuitry <NUM> and/or the energy detection unit <NUM> is configured to perform the UL re-transmission based on whether the energy detection indication indicates an energy level that is less than a pre-defined threshold value.

Although <FIG> and <FIG> show various "units" such as energy detection unit <NUM>, and re-transmission determination unit <NUM> as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry.

<FIG> is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of <FIG> and <FIG>, in accordance with one embodiment. The communication system may include a host computer <NUM>, a network node <NUM> and a WD <NUM>, which may be those described with reference to <FIG>. In a first step of the method, the host computer <NUM> provides user data (Block S <NUM>). In an optional substep of the first step, the host computer <NUM> provides the user data by executing a host application, such as, for example, the host application <NUM> (Block S102). In a second step, the host computer <NUM> initiates a transmission carrying the user data to the WD <NUM> (Block S <NUM>). In an optional third step, the network node <NUM> transmits to the WD <NUM> the user data which was carried in the transmission that the host computer <NUM> initiated, in accordance with the teachings of the embodiments described throughout this disclosure (Block S106). In an optional fourth step, the WD <NUM> executes a client application, such as, for example, the client application <NUM>, associated with the host application <NUM> executed by the host computer <NUM> (Block S <NUM>).

<FIG> is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of <FIG>, in accordance with one embodiment. The communication system may include a host computer <NUM>, a network node <NUM> and a WD <NUM>, which may be those described with reference to <FIG> and <FIG>. In a first step of the method, the host computer <NUM> provides user data (Block S110). In an optional substep (not shown) the host computer <NUM> provides the user data by executing a host application, such as, for example, the host application <NUM>. In a second step, the host computer <NUM> initiates a transmission carrying the user data to the WD <NUM> (Block <NUM>). In an optional third step, the WD <NUM> receives the user data carried in the transmission (Block S <NUM>).

<FIG> is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of <FIG>, in accordance with one embodiment. The communication system may include a host computer <NUM>, a network node <NUM> and a WD <NUM>, which may be those described with reference to <FIG> and <FIG>. In an optional first step of the method, the WD <NUM> receives input data provided by the host computer <NUM> (Block S1 <NUM>). In an optional substep of the first step, the WD <NUM> executes the client application <NUM>, which provides the user data in reaction to the received input data provided by the host computer <NUM> (Block S <NUM>). Additionally or alternatively, in an optional second step, the WD <NUM> provides user data (Block S120). In an optional substep of the second step, the WD provides the user data by executing a client application, such as, for example, client application <NUM> (Block S <NUM>). In providing the user data, the executed client application <NUM> may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the WD <NUM> may initiate, in an optional third substep, transmission of the user data to the host computer <NUM> (Block S124). In a fourth step of the method, the host computer <NUM> receives the user data transmitted from the WD <NUM>, in accordance with the teachings of the embodiments described throughout this disclosure (Block S126).

<FIG> is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of <FIG>, in accordance with one embodiment. The communication system may include a host computer <NUM>, a network node <NUM> and a WD <NUM>, which may be those described with reference to <FIG> and <FIG>. In an optional first step of the method, in accordance with the teachings of the embodiments described throughout this disclosure, the network node <NUM> receives user data from the WD <NUM> (Block S128). In an optional second step, the network node <NUM> initiates transmission of the received user data to the host computer <NUM> (Block S <NUM>). In a third step, the host computer <NUM> receives the user data carried in the transmission initiated by the network node <NUM> (Block S132).

<FIG> is a flowchart of an exemplary process in a network node <NUM> for providing for an energy detection indicator according to some embodiments of this disclosure. One or more Blocks and/or functions performed by network node <NUM> may be performed by one or more elements of network node <NUM> such as by the energy detection unit <NUM> in processing circuitry <NUM>, processor <NUM>, radio interface <NUM>, etc. The example process includes performing (Block <NUM>), such as for example via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, energy detection on assigned resources corresponding to a configured uplink grant for a wireless device <NUM>. The process includes, based on a level of the detected energy, one of: sending (Block S <NUM>), such as for example via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, an energy detection indication corresponding to the assigned resources associated with the configured uplink grant; and demodulating and decoding, such as via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, a transport block associated with the configured uplink grant.

In some embodiments, the method further includes if the transport block is correctly decoded, using an implicit hybrid automatic repeat request, HARQ, acknowledgement, ACK, scheme; and if the transport block is not correctly decoded, sending a dynamic grant for retransmission. In some embodiments, the dynamic grant for retransmission indicates to the wireless device a hybrid automatic repeat request, HARQ, non-acknowledgement, NACK, for the transport block. In some embodiments, based on the level of the detected energy, one of sending the energy detection indication and demodulating and decoding the transport block further including: if the level of the detected energy is less than a predefined threshold, sending, such as via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, the energy detection indication corresponding to the assigned resources associated with the configured uplink grant; and if the level of the detected energy is at least equal to the predefined threshold, demodulating and decoding, such as via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, the transport block associated with the configured uplink grant.

In some embodiments, the method further includes, as a result of sending the energy detection indication before a timer expires, receiving, such as via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, a retransmission of the transport block from the WD <NUM>. In some embodiments, the energy detection indication indicates to the WD <NUM> whether to retransmit data in a buffer. In some embodiments, sending the energy detection indication further includes sending, such as via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, the energy detection indication in a downlink control information, DCI, message. In some embodiments, sending the energy detection indication in the DCI message further includes setting, such as via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, at least one DCI field to a special value, the special value representing the energy detection indication.

In some embodiments, sending the energy detection indication further includes sending the energy detection indication in a group common downlink control information, DCI, message. In some embodiments, the energy detection indication in the group common DCI message includes at least one bitmap indicating energy detection in physical resource block, PRB, groups. In some embodiments, sending the energy detection indication further includes sending, such as via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, the energy detection indication in a physical downlink shared channel, PDSCH.

In some embodiments, performing the energy detection on the assigned resources corresponding to the configured uplink grant further includes performing, such as via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, a demodulation reference signal, DMRS, sequence detection on the assigned resources corresponding to the configured uplink grant, the DMRS sequence detection assuming that the wireless device has transmitted a physical uplink shared channel and an associated DMRS according to the configured uplink grant. In some embodiments, performing the energy detection on the assigned resources corresponding to the configured uplink grant further includes performing, such as via the energy detection unit <NUM>, processing circuitry <NUM>, processor <NUM>, communication interface <NUM> and/or radio interface <NUM>, the energy detection on the assigned resources based on a radio frequency signal detected on the assigned resources corresponding to the configured uplink grant.

In some embodiments, the method further includes communicating, such as for example via the energy detection unit <NUM> and/or the radio interface <NUM>, an indication of a level of the detected energy to the wireless device as part of a HARQ feedback scheme. In some embodiments, the method further includes at least one of: determining, such as for example via the energy detection unit <NUM>, whether the detected energy is less than or equal to a pre-defined threshold value; determining, such as for example via the energy detection unit <NUM>, whether or not to communicate an indication of a level of the detected energy based on whether the detected energy is less than or equal to the pre-defined threshold value; and determining, such as for example via the energy detection unit <NUM>, whether or not to demodulate and decode an uplink transmission on the assigned resources based on the level of the detected energy. In some embodiments, the method further includes communicating, such as for example via the energy detection unit <NUM> and/or the radio interface <NUM>, an indication of a level of the detected energy in a downlink control information (DCI) message. In some embodiments, the performing the energy detection comprises performing, such as for example via the energy detection unit <NUM>, a demodulation reference signal (DMRS) sequence detection.

<FIG> is a flowchart of an exemplary process in a wireless device <NUM> according to some embodiments of the present disclosure. One or more Blocks and/or functions performed by wireless device <NUM> may be performed by one or more elements of wireless device <NUM> such as by the retransmission determination unit <NUM> in processing circuitry <NUM>, processor <NUM>, radio interface <NUM>, etc. The example method includes receiving (Block S <NUM><NUM>), such as for example via radio interface <NUM>, processing circuitry <NUM>, processor <NUM> and/or retransmission determination unit <NUM>, an energy detection indication corresponding to assigned resources associated with a configured uplink grant. The method includes determining (Block S <NUM>), such as for example via the re-transmission determination unit <NUM>, processing circuitry <NUM>, processor <NUM> and/or radio interface <NUM>, whether to perform an uplink (UL) re-transmission based at least in part on the energy detection indication.

In some embodiments, the method further includes determining, such as for example via the retransmission determination unit <NUM>, processing circuitry <NUM>, processor <NUM> and/or radio interface <NUM>, whether data was transmitted in the assigned resources associated with the configured uplink grant, the uplink retransmission being conditioned on the data being transmitted in the assigned resources associated with the configured uplink grant. In some embodiments, the energy detection indication indicates a level of energy detected on the assigned resources associated with the configured uplink grant relative to a predefined threshold. In some embodiments, the method further includes if a dynamic grant for retransmission on resources associated with the configured uplink grant is received, retransmit on the resources based on the dynamic grant. In some embodiments, the dynamic grant for retransmission indicates to the wireless device <NUM> a hybrid automatic repeat request, HARQ, non-acknowledgement, NACK. In some embodiments, determining whether to perform the uplink retransmission based at least in part on the received energy detection indication further includes if the energy detection indication is received before a timer expires, assuming, such as for example via the re-transmission determination unit <NUM>, processing circuitry <NUM>, processor <NUM> and/or radio interface <NUM>, hybrid automatic repeat request, HARQ, non-acknowledgement, NACK and performing the uplink retransmission. In some embodiments, if no energy detection indication is received before the timer expires, assuming, such as for example via the re-transmission determination unit <NUM>, processing circuitry <NUM>, processor <NUM> and/or radio interface <NUM>, an implicit HARQ acknowledgement, ACK.

In some embodiments, the energy detection indication indicates to the WD <NUM> whether to retransmit data in a buffer. In some embodiments, receiving the energy detection indication further includes receiving, such as for example via the re-transmission determination unit <NUM>, processing circuitry <NUM>, processor <NUM> and/or radio interface <NUM>, the energy detection indication in a downlink control information, DCI, message. In some embodiments, receiving the energy detection indication in the DCI message further includes receiving, such as for example via the re-transmission determination unit <NUM>, processing circuitry <NUM>, processor <NUM> and/or radio interface <NUM>, at least one DCI field that is set to a special value, the special value representing the energy detection indication.

In some embodiments, receiving the energy detection indication further includes receiving, such as for example via the re-transmission determination unit <NUM>, processing circuitry <NUM>, processor <NUM> and/or radio interface <NUM>, the energy detection indication in a group common downlink control information, DCI, message. In some embodiments, the energy detection indication in the group common DCI message includes at least one bitmap indicating energy detection in physical resource block, PRB, groups. In some embodiments, receiving the energy detection indication further includes receiving, such as for example via the re-transmission determination unit <NUM>, processing circuitry <NUM>, processor <NUM> and/or radio interface <NUM>, the energy detection indication in a physical downlink shared channel, PDSCH.

In some embodiments, the energy detection indication indicates a level of energy detected by a network node on the assigned resources as part of a HARQ feedback scheme. In some embodiments, the energy detection indication is received in a downlink control information (DCI) message. In some embodiments, the method further includes performing, such as via the re-transmission determination unit <NUM>, the UL re-transmission based on whether the energy detection indication indicates an energy level that is less than a pre-defined threshold value.

Having generally described some embodiments for an energy detection indicator, a more detailed description of some of the embodiments is described below, which may be implemented by network node <NUM> and/or wireless device <NUM>.

In an uplink grant-free transmission, the network node <NUM> may receive data over a physical uplink shared channel (PUSCH) according to the RRC configuration. In some embodiments of this disclosure, it is proposed that the network node <NUM> perform an energy detection process (in addition to the network node's <NUM> typical activities of decoding data in the PUSCH) over the assigned time-frequency resources for the WD's <NUM> configured grants. An example is shown in <FIG> illustrates a schematic of an example energy detection scheme for an uplink grant-free transmission. In <FIG>, the energy detector unit <NUM> in the network node <NUM> examines whether the energy level over the assigned resources is smaller than a pre-defined threshold value. If so, the network node <NUM> may assume Case <NUM> (e.g., WD <NUM> sent UL transmission on the assigned resources unsuccessfully). Thus, the network node <NUM> can send an energy level feedback to the WD <NUM> indicating e.g., the detected energy level. Otherwise (e.g., if the detected energy level meets or exceeds the pre-defined threshold value), the network node <NUM> may not send the energy feedback signal to the WD <NUM>.

In some further embodiments, a timer may be defined for the energy level feedback. In some embodiments, the energy level feedback is required to be sent to the WD <NUM> before such timer expires. If no energy level feedback is sent to WD <NUM> before the timer expires, the WD <NUM> may assume Case <NUM> (e.g., network node <NUM> received and decoded uplink transmission successfully); thus an implicit ACK scheme can be used and the WD <NUM> can flush its buffer for the corresponding transport block. In some embodiments, if an energy level feedback is received by the WD <NUM> before the timer expires, the WD <NUM> may assume Case <NUM> and retransmit the UL transmission.

<FIG> illustrates an example of the WD <NUM> receiving the feedback (e.g., energy detection indication) from the network node <NUM> as a result of the detected energy being lower than the threshold. In some embodiments, since the WD <NUM> may know whether or not, in the previous transmission occasion, the WD <NUM> sent UL data, the WD <NUM> can interpret the received energy detector indicator as HARQ NACK or a normal incident. <FIG> illustrates an example flowchart of a WD <NUM> decision-making process based on the received signals from the network node <NUM>. As shown in <FIG>, there may be data in the WD <NUM> buffer (Block S150). The WD <NUM> may determine whether data was transmitted on the previous configured grant (Block S152). If no, operation may continue based on the current specification (Block S154). On the other hand, if yes (i.e., data was transmitted in the previous configured grant), the WD <NUM> may determine whether the energy detector signal is less than (or at most meets) a threshold (Block S156). If yes, the WD <NUM> may consider it a NACK and arrange for re-transmission of the contents of the buffer (Block S158). If no (e.g., the energy detector signal is more than (or at least meets) a threshold, the WD <NUM> may continue operation based on the current specification (e.g., in some embodiments, this may include flushing the buffer when the timer expires as described in the introduction section).

In one embodiment, the energy detection may be based on baseband signals and using a demodulation reference signal (DMRS) sequence detection. That is, the network node <NUM> may perform DMRS sequence detection assuming the WD <NUM> has transmitted PUSCH and associated DMRS according to its UL configured grant configuration. In another embodiment, the energy detection can be based on a radio frequency (RF) signal.

In some embodiments, the energy-detection indicator is sent in a group-common DCI to the WD <NUM>. In some embodiments, the energy-detection indicator is a bitmap of Physical Resource Block (PRB) groups. In one example of such embodiments the PRBs may be divided into resource block groups (RBGs). In one example, an RBG may include a pair of adjacent PRBs, and the PRBs may be grouped into pairs of PRBs such as (PRB0, PRB1), (PRB2, PRB3), (PRB4, PRB5), (PRB6, PRB7), etc. In some embodiments, if the network node <NUM> does not detect energy in a set of PRBs, such as PRB4-PRB7, for a configured grant transmission opportunity, the network node <NUM> may transmit a bitmap or a sequence of bits (e.g., <NUM>. In some such embodiments, the group-common DCI may include and/or indicate, implicitly or explicitly, a time reference back in time relative to the time of reception of the group-common DCI. In other embodiments, when multiple configured grants are utilizing same or overlapping PRBs there may be more than one bitmap. For example, a first configured grant may use PRB2-PRB3 in a first part of a slot; while a second configured grant may also use PRB2-PRB3, but in a second part of a slot. In such examples the group-common DCI may comprise a first and second bitmap referencing a first and second part of a slot, respectively.

In one embodiment, for each WD <NUM> with an active UL configured grant (CG), the network node <NUM> may perform PUSCH detection according to each individual WD's <NUM> UL configured grant configuration, including cg-DMRS-Configuration, resourceAllocation, repK, periodicity, etc. In some embodiments, a WD <NUM> with an active UL configured grant may be denoted WD_A. The network node <NUM> may then perform energy detection according to the UL configured grant configuration of WD_A, for example, by sequence detection of DMRS according WD_A's cg-DMRS-Configuration, frequencyHopping, repK, etc. The energy detection may be performed for each occasion that the WD-A may transmit a TB associated with the CG. In some embodiments, the energy detection may be performed before the network node <NUM> performs demodulation and decoding of a potential TB carried by the PUSCH associated with the UL configured grant. In some embodiments, for occasion Tj that the WD-A may transmit a TB associated with the CG,.

In some embodiments, how to set the value of threshold_A for WD_A may be determined by the network node <NUM> implementation. According to the invention, the threshold A can be set considering the specific configuration of WD_A, for example, the DMRS configuration, antenna port configuration, PUSCH power control configuration of WD_A, etc. In some embodiments, the threshold_A can be the same as threshold_B of a different WD <NUM>, WD_B, for example, when WD_A and WD_B have similar configurations. Alternatively, the threshold_A can be different from threshold_B WD_B, for example, when WD_A and WD_B have different DMRS configuration.

In some embodiments, the energy level feedback can be signaled (e.g., by network node <NUM>) by setting fields of DCI format 0_0 to special values. In one example, the following setting of special fields may provide for the energy_detection indicator as follows, in Table <NUM>:.

Note that the "HARQ process number" field in DCI is shown set to the actual HARQ process number of the associated TB.

For the case where repK><NUM> is used, the WD <NUM> may be allowed to start PUSCH transmission at multiple slots for e.g., 3GPP Rel-<NUM> (and possibly mini-slots for future releases). To be efficient with feedback transmission, the network node <NUM> may in some embodiments transmit only one energy_detection_indicator for each period, when the network node <NUM> has decided that WD <NUM> didn't transmit TB for the entire set of repK slots (or mini-slots).

If the techniques disclosed herein are applied to configured grant UL transmission with an aperiodic traffic nature, the indicator may be deactivated or may be sent in a less frequent manner. In one embodiment, the indicator may be sent only periodically with possibly a larger period than the configured grant UL period. In another embodiment, the indication may be deactivated when a condition is met, e.g., when a number of consecutive indication transmissions exceeds a certain threshold.

Once the indication is deactivated, it may be reactivated following certain condition, e.g.,.

In one embodiment, the usage of indication may be according to the indication state (e.g., activated or deactivated) configured in e.g., RRC. If the indication is set to activated, the techniques in this disclosure for energy detection feedback may be used; otherwise if deactivated no energy detection indication may be used.

In some embodiments, comparison operations for a threshold or threshold value may be indicated such as greater than, or less than, or equal to. It should be understood that different types of operations can be used in other embodiments to implement the techniques in this disclosure. For example, where one embodiment may include performing a particular action if a detected level is less than a threshold, another embodiment may include performing the particular action if a detected level is less than or equal to the threshold. Any such comparison operators may be used. Furthermore, in some embodiments, there may be more than one threshold, such as for example, a hierarchy of threshold levels, such as a first threshold level where one type of indicator is sent in one message and, for example, another threshold level that can be used to trigger yet another type of indicator or another type of message or even addition information in the message to be sent.

Claim 1:
A method implemented in a network node (<NUM>), the method comprising: performing (S134) energy detection on assigned resources corresponding to a configured uplink grant for a wireless device (<NUM>), WD, wherein performing the energy detection on the assigned resources corresponding to the configured uplink grant further comprises one of:
performing a demodulation reference signal, DMRS, sequence detection on the assigned resources corresponding to the configured uplink grant, the DMRS sequence detection assuming that the wireless device has transmitted a transport block on a physical uplink shared channel and an associated DMRS according to the configured uplink grant; and
performing the energy detection on the assigned resources corresponding to the configured uplink grant on a physical uplink shared channel on which a transport block is transmitted by the wireless device, based on a radio frequency signal detected on the assigned resources corresponding to the configured uplink grant; and based on a level of the detected energy, one of:
when the level of the detected energy is less than a threshold, sending (S136) an energy detection indication corresponding to the assigned resources associated with the configured uplink grant, wherein as a result of sending the energy detection indication before a timer started when the transport block is sent on the physical uplink shared channel expires, receiving a retransmission of the transport block from the WD (<NUM>); and
when the level of the detected energy is at least equal to the threshold, demodulating and decoding the transport block associated with the configured uplink grant,
wherein the threshold is set considering the specific configuration of the WD (<NUM>), which configuration comprises one or more out of: DMRS configuration, antenna port configuration, PUSCH power control configuration of the WD (<NUM>).