Patent Description:
For better communication quality, a reception device may transmit information about acknowledgement to the transmission device, about a received data or any other information. Thus, the transmission device may understand whether the data or any other information is received and decoded by the reception device.

However, in a multicast communication (one transmission device to multiple reception device), it is very hard for all the reception devices to transmit the information about acknowledgement to the transmission device.

<NPL>, describes multicast HARQ-ACK operation.

Various embodiments of the present disclosure propose a solution for acknowledgement in multicast, particularly the transmission device may be aware of which data or other information needs to be retransmitted. More specifically, the present disclosure provides a method according to claim <NUM>, a terminal device according to claim <NUM>, and a computer program according to claim <NUM>. The dependent claims define further embodiments.

According to any of the embodiments of the present disclosure, a manner for acknowledgement in multicast is provided. Particularly, group-UEs are enabled to indicate NACK signals for multiple HARQ processes in the same uplink slot.

The disclosure itself, the preferable mode of use and further objectives are best understood by reference to the following detailed description of the embodiments when read in conjunction with the accompanying drawings, in which:.

As used herein, the term "communication network" refers to a network following any suitable communication standards, such as new radio (NR), long term evolution (LTE), LTE-Advanced, wideband code division multiple access (WCDMA), high-speed packet access (HSPA), and so on. Furthermore, the communications between a terminal device and a network node in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (<NUM>), the second generation (<NUM>), <NUM>, <NUM>, the third generation (<NUM>), <NUM>, <NUM>, <NUM> communication protocols, and/or any other protocols either currently known or to be developed in the future.

The term "network node" refers to a network device in a communication network via which a terminal device accesses to the network and receives services therefrom. The network node may refer to a base station (BS), an access point (AP), a multi-cell/multicast coordination entity (MCE), a controller or any other suitable device in a wireless communication network. The BS may be, for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a next generation NodeB (gNodeB or gNB), a remote radio unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, a low power node such as a femto, a pico, and so forth.

Yet further examples of the network node comprise multi-standard radio (MSR) radio equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, positioning nodes and/or the like. More generally, however, the network node may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a terminal device access to a wireless communication network or to provide some service to a terminal device that has accessed to the wireless communication network.

The term "terminal device" refers to any end device that can access a communication network and receive services therefrom. By way of example and not limitation, the terminal device may refer to a mobile terminal, a user equipment (UE), or other suitable devices. The UE may be, for example, a subscriber station, a portable subscriber station, a mobile station (MS) or an access terminal (AT). The terminal device may include, but not limited to, portable computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, a mobile phone, a cellular phone, a smart phone, a tablet, a wearable device, a personal digital assistant (PDA), a vehicle, and the like.

As yet another specific example, in an Internet of things (IoT) scenario, a terminal device may also be called an IoT device and represent a machine or other device that performs monitoring, sensing and/or measurements etc., and transmits the results of such monitoring, sensing and/or measurements etc. to another terminal device and/or a network equipment. The terminal device may in this case be a machine-to-machine (M2M) device, which may in a 3rd generation partnership project (3GPP) context be referred to as a machine-type communication (MTC) device.

As one particular example, the terminal device may be a UE implementing the 3GPP narrow band Internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances, e.g. refrigerators, televisions, personal wearables such as watches etc. In other scenarios, a terminal device may represent a vehicle or other equipment, for example, a medical instrument that is capable of monitoring, sensing and/or reporting etc. on its operational status or other functions associated with its operation.

The term "phase rotation" is referred in the art also as "cyclic shift".

As an implementation example without limitation, <NUM>rd generation partnership project New Radio (3GPP NR) illustrated below.

In NR, an adaptive retransmission scheme called Hybrid Automatic Repeat reQuest (HARQ) is widely used. According to this scheme the receiver of a packet sends back a positive (ACK) or a negative (NACK) acknowledgement to the sender, depending on whether the receiver has decoded the transport block successfully or unsuccessfully, respectively. If it is an ACK the sender will transmit a new transport block and if it is a NACK the sender will retransmit either the same version or a different version of the initial transport block. There can be multiple retransmission attempts for a single data transport block. Typically, the HARQ is most suitable for unicast and groupcast transmissions because these casting modes often have some ways of identifying the source and the destination of a transport block (e.g. source and destination identifiers, IDs), which facilitates both the feedbacks and data retransmissions. Currently, HARQ is often not used in broadcast mode where either feedback and retransmission are not of interest or their benefits cannot outweigh the associated complexity due to many participants.

Therefore, improvement is needed for implementing the retransmission for retransmission in multicast.

As an example without limitation, multicast in the downlink from a gNB to a group of UEs is illustrated below. The term multicast and Point-To-Multipoint (PTM) are used interchangeably.

<FIG> is a diagram showing an example for configuring HARQ_feedback timing.

The actual time-frequency resource that a UE shall use for HARQ feedback is determined as outlined in the following.

In the DCI, a PDSCH-to-HARQ_feedback timing indicator is contained that points to an element of an RRC-configurable list of timing for given PDSCH to the DL ACK (see 3GPP technical specification, TS <NUM> V16. <NUM>, clause <NUM>. <NUM>) contained in Information Element (IE) dl-DataToUL-ACK as in illustrated in <FIG>. The unit of the timings is a slot.

<FIG> is a diagram showing an example for feedback in PUCCH.

Within so defined slots in <FIG>, the time-frequency-code resource in terms of OFDM-symbols, PRBs and possibly an orthogonal code is determined by a combination of the <NUM> bit PUCCH Resource Indicator PRI in the DCI and RRC-configured PUCCH resources sets, as illustrated in the <FIG>, where ARI (Acknowledgement Resource Indicator) is stands for the standardized PRI.

Which resource set is used is determined from the UCI payload information in # bits as indicated by the x-axis.

A PUCCH resource set contains at least four PUCCH resource configurations, where each resource configuration contains the PUCCH format to use and all the parameters necessary for that format. The same PUCCH config may also appear for different formats.

The PUCCH configurations can be regarded as candidates for a UE, and the gNB can dynamically address the candidates in each DCI. This is advantageous as not all UEs are always scheduled, so for every uplink slot the gNB can dynamically assign a PUCCH config for those UEs that have actually a need, e.g. because the gNB has scheduled, using the DCI, data on the PDSCH before and the UE therefore are required to transmit A/N (ACK/NACK).

PUCCH format <NUM> occupies one OFDM symbol and one physical resource block (PRB) as shown in the subsequent figure.

<FIG> is a diagram showing an example for including a ACK/NACK bit in one resource block.

The transmitted sequence is generated by different phase rotations of the same underlying length-<NUM> base sequence. Thus, the phase rotation applied to the base sequence carries the information. In other words, the information selects one of several phase-rotated sequences. Twelve different phase rotations are defined for the same base sequence, providing up to <NUM> different orthogonal sequences from each base sequence.

In NR Rel-<NUM> the PTM transmission to a group of UEs is being standardized. It is agreed that group UEs may use NACK-only signaling for HARQ processes where decoding has failed, i.e. they will transmit only NACK but not ACK. If the UE needs to transmit NACK for only one HARQ process in an uplink slot, then all UEs having the need are assumed to transmit their NACK signal in the same PUCCH resource. The gNB will monitor the PUCCH resource but will not be able to discern which UE has transmitted NACK. If the detect energy received exceeds a configured threshold then the gNB assumes at least one UE has transmitted NACK and accordingly the gNB will retransmit the transport block associated with the HARQ process.

The gNB may instruct the group UEs to signal NACK for a set of HARQ processes in the same uplink slot, e.g. for all HARQ processes for which the gNB has transmitted a transport block since over a number of downlink slots and component carriers.

However, a current UE supports transmitting on only one PUCCH resource in a slot. The information the UE has to transmit, e.g. A/N from multiple HARQ processes, is gathered and constitutes the UCI payload. A PUCCH format is chosen that fits the UCI payload, as shown in a figure in the previous section. The gathered information is jointly encoded and transmitted in the PUCCH format, filling one PUCCH resource.

For the NACK-only signaling foreseen for PTM in Rel-<NUM>, it is desired that all UEs can use the same set of PUCCH resources and the signals transmitted from different UEs for NACK-indication are not orthogonal. Since different UEs may have to indicate NACK for different subsets of HARQ processes, an representation must be so that indications for different HARQ processes do not interfere with each other.

Embodiments of the present disclosure provide solutions with improvements.

Various embodiments of the present disclosure propose a solution for acknowledgement in multicast, particularly the transmission device may be aware of which data or other information needs to be retransmitted.

<FIG> is a flow chart showing a method performed by a terminal device, according to embodiments of the present disclosure.

According to an embodiment <NUM> of the present disclosure, there is provided a method performed by a terminal device, comprising:.

As an example, the information about acknowledgement may include at least one NACK (negative acknowledgement).

Embodiment <NUM>, the method according to embodiment <NUM>, wherein the configuration is received from the network node.

Embodiment <NUM>, the method according to any of embodiments <NUM> to <NUM>, wherein the configuration indicates using multiple Physical Uplink Control Channel, PUCCH, resources in a slot.

Embodiment <NUM>, the method according to embodiment <NUM>,.

As an exemplary alternative embodiment of the present disclosure, the multiple PUCCH resources may include M = <NUM>^N - <NUM> PUCCH resources for N HARQ processes, M, N are positive integers. Each terminal device in the plurality of terminal devices transmits on one of the PUCCH resources according to a subset of HARQ processes for which the terminal device needs to signal NACK. The terminal device transmits on at least one PUCCH resource of the multiple PUCCH resources if the terminal device has at least one NACK, and the terminal device does not transmit on the multiple PUCCH resources if the terminal device does not have a NACK.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein each PUCCH resource of the multiple PUCCH resources represents one HARQ process and the terminal device transmits multiple NACK signals, one NACK signal on each PUCCH resource corresponding to a HARQ process for which the terminal device has to signal a NACK.

Embodiment <NUM>, the method according to any of embodiments <NUM> to <NUM>, wherein the configuration indicates using PUCCH format <NUM> phase rotations as a dimension in addition to OFDM-symbol and PRB.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein each rotation is associated with a HARQ process.

Embodiment <NUM>, the method according to any of embodiments <NUM> to <NUM>, wherein the configuration indicates associating each NACK signal with a set of HARQ processes, and wherein the plurality of terminal devices uses the same PUCCH resource for the NACK-only signal relating to the same subset of HARQ processes.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein a size of the subset is <NUM>.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein the terminal device transmits the NACK signal if at least one process of the associated subset of HARQ processes has a decoding failure.

<FIG> is a flow chart showing a method performed by a network node (e.g. a base station), according to embodiments of the present disclosure.

Embodiment <NUM>: a method performed by a network node (the network node may be a base station), comprising:.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein the configuration is transmitted to the plurality of terminal devices.

Embodiment <NUM>, a terminal device <NUM>, comprising:.

Embodiment <NUM>, network node <NUM>, comprising:.

Embodiment <NUM>, computer-readable medium <NUM> having computer program codes <NUM> embodied thereon for use with a network node <NUM>, wherein the computer program codes comprise codes for performing the method according to any one of embodiments <NUM> to <NUM> and <NUM> to <NUM>.

Embodiment <NUM>, computer-readable medium <NUM> having computer program codes <NUM> embodied thereon for use with a terminal device <NUM>, wherein the computer program codes comprise codes for performing the method according to any one of embodiments <NUM> to <NUM> and and <NUM> to <NUM>.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein a HARQ codeword may comprises of at least Q bits for at least Q HARQ processes, wherein each of the bits may be associated to one HARQ process and each bit indicates if a NACK for the associated HARQ process needs to be signaled, wherein the multiple PUCCH resources may include <NUM>^N PUCCH resources for the Q HARQ processes with Q><NUM> and Q>N, Q and N are positive integer values, wherein possible HARQ codewords may be grouped so that (<NUM>^Q/<NUM>^N) HARQ codewords are associated to each PUCCH resource except for one PUCCH resource, wherein the terminal device (<NUM>) may determine a HARQ codeword according to a subset of HARQ processes for which the terminal device (<NUM>) needs to signal NACK, and wherein the terminal device (<NUM>) may transmit on the PUCCH resource where the determined HARQ codeword is associated to.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein the HARQ codewords of one group may differ by up to Q-N bit(s).

Embodiment <NUM>, the method according to embodiment <NUM>, wherein a HARQ codeword may comprise of at least Q bits for at least Q HARQ processes, wherein each of the bits may be associated to one HARQ process and each bit may indicate if a NACK for the associated HARQ process needs to be signaled, wherein the multiple PUCCH resources may include <NUM>^N-<NUM> PUCCH resources for the Q HARQ processes with Q>N, Q and N are positive integer values, wherein HARQ codewords may be grouped so that (<NUM>^Q/<NUM>^N) HARQ codewords are associated to each PUCCH resource except for one PUCCH resource, wherein the terminal device (<NUM>) may determine a HARQ codeword according to a subset of HARQ processes for which the terminal device (<NUM>) needs to signal NACK, and wherein the terminal device (<NUM>) may transmit on the PUCCH resource where the determined HARQ codeword is associated to.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein the HARQ codewords of one group may differ by up to Q-N bit with the exception of one group where the HARQ codewords may differ by up to Q-N+<NUM> bit.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein a HARQ codeword may comprise of at least Q bits for at least Q HARQ processes, wherein each of the bits may be associated with one HARQ process and each bit may indicate if a NACK for the associated HARQ process needs to be signaled, wherein the multiple PUCCH resources may include <NUM>^N PUCCH resources for the Q HARQ processes with Q><NUM> and Q>N, Q and N are positive integer values, wherein multiple HARQ codewords may be grouped and associated to a PUCCH resource based on the number of NACKs coded into the HARQ codeword; and wherein the terminal device (<NUM>) may determine a HARQ codeword according to a subset of HARQ processes for which the terminal device (<NUM>) needs to signal NACK; and wherein the terminal device (<NUM>) may transmit on the PUCCH resource where the determined HARQ codeword is associated to.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein a HARQ codeword may comprise of at least Q bits for at least Q HARQ processes, wherein each of the bits may be associated with one HARQ process and each bit may indicate if a NACK for the associated HARQ process needs to be signaled, wherein the multiple PUCCH resources may include <NUM>^N-Z PUCCH resources for the Q HARQ processes with Q>N, <NUM>^N-<NUM>>Z><NUM>, Q and N and Z are positive integer values, wherein multiple HARQ codewords may be grouped and associated to a PUCCH resource based on the number of NACKs coded into the HARQ codeword, wherein the terminal device (<NUM>) may determine a HARQ codeword according to a subset of HARQ processes for which the terminal device (<NUM>) needs to signal NACK, and wherein the terminal device (<NUM>) may transmit on the PUCCH resource where the determined HARQ codeword is associated to.

Embodiment <NUM>, the method according to embodiment <NUM> or <NUM>, wherein the number of HARQ codewords per group may increase with the number of NACKs coded into the HARQ codeword.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein a HARQ codeword may comprise of at least Q bits for at least Q HARQ processes, wherein each of the bits may be associated with one HARQ process and each bit may indicate if a NACK for the associated HARQ process needs to be signaled, wherein Q><NUM> and Q being an integer value; and wherein each HARQ codeword may be associated to one phase rotation.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein multiple HARQ codewords may be associated to the same phase rotation.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein the multiple HARQ codewords may be associated to the same phase rotation based on the number of NACKs coded into the HARQ codeword.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein maximum one HARQ codeword may be associated to a phase rotation, and wherein HARQ codewords of adjacent phase rotations with associated HARQ codewords may differ only in one bit.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein Q may be bigger than <NUM>.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein a HARQ codeword may comprises of at least Q bits for at least Q HARQ processes, wherein each of the bits may be associated to one HARQ process and each bit indicates if a NACK for the associated HARQ process needs to be signaled, wherein the multiple PUCCH resources may include <NUM>^N PUCCH resources for the Q HARQ processes with Q><NUM> and Q>N, Q and N are positive integer values, wherein possible HARQ codewords may be grouped so that (<NUM>^Q/<NUM>^N) HARQ codewords are associated to each PUCCH resource except for one PUCCH resource, wherein the terminal device (<NUM>) may determine a HARQ codeword according to a subset of HARQ processes for which the terminal device (<NUM>) needs to signal NACK; and wherein the terminal device (<NUM>) may transmit on the PUCCH resource where the determined HARQ codeword is associated to.

Embodiment <NUM>, the method according to embodiment <NUM> wherein the HARQ codewords of one group may differ by up to Q-N bit(s).

Embodiment <NUM>, the method according to embodiment <NUM> wherein the HARQ codewords of one group may differ by up to Q-N bit with the exception of one group where the HARQ codewords may differ by up to Q-N+<NUM> bit.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein a HARQ codeword may comprise of at least Q bits for at least Q HARQ processes, wherein each of the bits may be associated with one HARQ process and each bit may indicate if a NACK for the associated HARQ process needs to be signaled, wherein the multiple PUCCH resources may include <NUM>^N PUCCH resources for the Q HARQ processes with Q><NUM> and Q>N, Q and N are positive integer values, wherein mutliple HARQ codewords may be grouped and associated to a PUCCH resource based on the number of NACKs coded into the HARQ codeword, wherein the terminal device (<NUM>) may determine a HARQ codeword according to a subset of HARQ processes for which the terminal device (<NUM>) needs to signal NACK, wherein the terminal device (<NUM>) may transmit on the PUCCH resource where the determined HARQ codeword is associated to.

Embodiment <NUM>, the method according to embodiment <NUM>, wherein a HARQ codeword may comprise of at least Q bits for at least Q HARQ processes, wherein each of the bits may be associated with one HARQ process and each bit may indicate if a NACK for the associated HARQ process needs to be signaled, wherein the multiple PUCCH resources may include <NUM>^N-Z PUCCH resources for the Q HARQ processes with Q>N and <NUM>^N-<NUM>>Z><NUM>, Q and N and Z are positive integer values, wherein multiple HARQ codewords may be grouped and associated to a PUCCH resource based on the number of NACKs coded into the HARQ codeword, wherein the terminal device (<NUM>) may determine a HARQ codeword according to a subset of HARQ processes for which the terminal device (<NUM>) needs to signal NACK, and wherein the terminal device (<NUM>) may transmit on the PUCCH resource where the determined HARQ codeword is associated to.

Embodiment <NUM>, the method according to embodiment <NUM> or <NUM> wherein the number of HARQ codewords per group may increase with the number of NACKs coded into the HARQ codeword.

Embodiment <NUM>, the method according to embodiment <NUM> wherein a HARQ codeword may comprise of at least Q bits for at least Q HARQ processes, wherein each of the bits may be associated with one HARQ process and each bit may indicate if a NACK for the associated HARQ process needs to be signaled, wherein Q><NUM> and Q being an integer value; and wherein each HARQ codeword may be associated to one phase rotation.

Embodiment <NUM>, the method according to embodiment <NUM> wherein multiple HARQ codewords may be associated to the same phase rotation.

Embodiment <NUM>, the method according to embodiment <NUM> wherein the multiple HARQ codewords may be associated to the same phase rotation based on the number of NACKs coded into the HARQ codeword.

Embodiment <NUM>, the method according to embodiment <NUM> wherein maximum one HARQ codeword may be associated to a phase rotation; and wherein HARQ codewords of adjacent phase rotations with associated HARQ codewords may differ only in one bit.

Embodiment <NUM>, the method according to embodiment <NUM> wherein Q may be bigger than <NUM>.

In present disclosure, the solution may use an existing PUCCH format for transmitting NACK feedback signals for multiple PDSCHs from multiple UEs in a multicast group.

The following variants can be used, where the first <NUM> configurations are mutually exclusive, the other <NUM> configurations can be combined with either of the first <NUM> configuration.

Configuration <NUM>, using multiple PUCCH resources in the same slot, M = (<NUM>^N PUCCH resources for N HARQ processes, each UE transmits on one of the resources according to the subset of HARQ processes for which the UE needs to signal NACK); M, N are positive integers;.

Configuration <NUM>, using multiple PUCCH resources in the same slot, where each PUCCH resource represents one HARQ process and the UE needs to transmit multiple NACK signals, one on each PUCCH resource corresponding to a HARQ process for which the UE has to signal a NACK;.

Configuration <NUM>, using multiple PUCCH resources in the same slot, M = <NUM>^N-<NUM> PUCCH resources for N HARQ processes, each UE transmits on one of the resources according to the subset of HARQ processes for which the UE needs to signal NACK), UE does not transmit a signal if it does not need to indicate any NACK. No PUCCH resource corresponding to the all-zero HARQ codeword is needed; M, N are positive integers.

Configuration <NUM>, using multiple PUCCH resources in the same slot, <NUM>^N PUCCH resources for Q HARQ processes with Q><NUM>, Q>N, HARQ codewords are grouped so that (<NUM>^Q/<NUM>^N) HARQ codewords are associated to each PUCCH resource except for one PUCCH resource, each UE transmits on one of the PUCCH resources according to the subset of HARQ processes for which the UE needs to signal NACK and the resulting HARQ codeword, HARQ codewords of one group may differ by up to Q-N bit(s); Q and N are positive integer values.

Configuration <NUM>, using multiple PUCCH resources in the same slot, <NUM>^N-<NUM> PUCCH resources for Q HARQ processes with Q>N, HARQ codewords are grouped so that (<NUM>^Q/<NUM>^N) HARQ codewords are associated to each PUCCH resource except for one PUCCH resource, each UE transmits on one of the PUCCH resources according to the subset of HARQ processes for which the UE needs to signal NACK and the resulting HARQ codeword; Q and N are positive integer values, HARQ codewords of one group may differ by up to Q-N bit with the exception of one group where the HARQ codewords may differ by up to Q-N+<NUM> bit.

Configuration <NUM>, using multiple PUCCH resources in the same slot, <NUM>^N PUCCH resources for Q HARQ processes with Q><NUM>, Q>N, mutliple HARQ codewords are grouped and associated to a PUCCH resource based on the number of NACKs coded into the HARQ codeword, each UE transmits on one of the PUCCH resources according to the subset of HARQ processes for which the UE needs to signal NACK and the resulting HARQ codeword, the number of HARQ codewords per group may increase with the number of NACKs coded into the HARQ codeword; Q and N are positive integer values.

Configuration <NUM>, using multiple PUCCH resources in the same slot, <NUM>^N-Z PUCCH resources for Q HARQ processes with Q>N, <NUM>^N-<NUM>>Z><NUM>, mutliple HARQ codewords are grouped and associated to a PUCCH resource based on the number of NACKs coded into the HARQ codeword, each UE transmits on one of the PUCCH resources according to the subset of HARQ processes for which the UE needs to signal NACK and the resulting HARQ codeword, the number of HARQ codewords per group may increase with the number of NACKs coded into the HARQ codeword; Q and N and Z are positive integer values.

Configuration <NUM>, using the PUCCH format <NUM> phase rotations as dimension in addition to OFDM-symbol and PRB, i.e., associate each rotation with a HARQ process;.

Configuration <NUM>, associating each NACK signal with a set of HARQ processes, where multiple UEs use the same PUCCH resource for the NACK-only signal relating to the same subset of HARQ processes, and the subset size may reduce to <NUM>. A UE transmits the NACK signal if at least one process of the associated subset of HARQ processes has a decoding failure and the gNB accordingly retransmits the transport blocks of all HARQ processes.

According to embodiments of the present disclosure, group-UEs are enabled to indicate NACK signals for multiple HARQ processes in the same uplink slot.

Further detailed embodiments may be further illustrated below.

In one embodiment, the gNB configures M=<NUM>^N PUCCH format <NUM> resources in a slot where N equal to the number of HARQ processes that need to send feedback in one slot. Each UE regards a HARQ process as a bit in a binary (HARQ) codeword , where the bit is set if the UE needs to transmit a NACK for that process. The PRI determines the bit position in the codeword. The UE then uses the codeword to address one out of the M PUCCH resources and transmits a PUCCH format <NUM> NACK signal on that resource. The gNB performs energy detection on each of the M PUCCH resources to detect which codewords Wi of the M codewords (i is an index number of codeword) have been signaled by any of the UEs. The gNB combines the codewords Wi by the logical OR operator to obtain a single codeword W. Each set bit in the (HARQ) codeword indicates to the gNB that at least one UE has signaled a NACK for the corresponding process. The gNB may then retransmit the corresponding transport blocks.

For example, a codeword "<NUM>" may indicate that a first process/block and a third process/block need to be retransmitted, with each "<NUM>" indicating one specific process/block.

One specific situation of this embodiment is that if a UE does not need to indicate NACK for any HARQ process, this corresponds to a codeword of all-zero bits and the UE would transmit a PUCCH format <NUM> signal on the resource addressed by this codeword.

More specifically, the UE (terminal device) spends battery power on the signal and the aggregate power from all UEs transmitting on this resource can cause intra- and intercell interference. The gNB does not benefit from the signal on this resource, because if the gNB also detects energy on the other PUCCH resources it knows the corresponding transport blocks need to be retransmitted, and if it does not detect energy in any other PUCCH resource then the gNB needs to assume that no UE has indicated a NACK, regardless of the energy detected on the resource corresponding to the all-zero codeword.

A further improved solution to this problem is that the UE does not transmit a signal if it does not need to indicate any NACK. The PUCCH resource corresponding to the all-zero codeword will thereby not be used for transmission by any of the group-UEs and may be reused for other purpose, e.g. by a UE for transmitting a HARQ A/N signal for a PTP (point to point) link. In one embodiment the gNB does not configure this PUCCH resource to the group-UEs, i.e. the total number of configured PUCCH resources for the group-UEs is M=<NUM>^N-<NUM>. Further advantage of this improved solution will be that UE battery power is not wasted, intra- and inter-cell interference is reduced and one PUCCH resource is saved.

In a still further improved solution multiple codewords can be mapped to the same PUCCH resource (bundeled) as shown in the example of <FIG>. This safes PUCCH resources, but may lead to unnecessary re-transmissions.

A HARQ codeword may comprise of at least Q bits for at least Q HARQ processes. Each of the bits may be associated to one HARQ process, and each bit may indicate if a NACK for the associated HARQ process needs to be signaled.

<FIG> shows one embodiment where for a given number Q of HARQ processes (each belonging to one transport block, TB) a number <NUM>^N of PUCCH resources is reserved, where Q><NUM> and Q>N, both are positive integer numbers. The possible HARQ feedback codewords alternatives (e.g. <NUM>, <NUM>, etc) are grouped (bundled) so that (<NUM>^Q / <NUM>^N) HARQ codewords (from here onwards referred as "codewords") are associated to each PUCCH resource except for one PUCCH resource (since transmitting of the <NUM> codeword is not needed as explained above, the number of codewords is odd which results in one codeword group with one associated codeword less). One constraint for grouping codewords may be that the grouped codewords may differ by up to Q-N bit(s).

In the example shown in <FIG> four HARQ processes are assumed (Q=<NUM>) and <NUM> PUCCH resources are reserved (N=<NUM>). For the <NUM> HARQ processes <NUM> feedback codewords (number <NUM>-<NUM>) are possible. Since only <NUM> PUCCH resources are available, <NUM>^Q/<NUM>^N = <NUM>/<NUM> = <NUM> codewords are associated (grouped/bundled) to one PUCCH resource, except for PUCCH #<NUM> resource. In other words, the bundling size is <NUM> for <NUM> PUCCH resources and <NUM> for PUCCH #<NUM> resource. A "<NUM>" in the codeword signifies a "NACK". All zero codeword is not sent. The <NUM> codewords associated to PUCCH#<NUM> - PUCH#<NUM> resource differ by Q-N=<NUM>-<NUM>=<NUM> bit.

The terminal device will then determine a HARQ codeword according to the subset of HARQ processes for which it needs to signal NACK, and transmit on the PUCCH resource where the determined HARQ codeword is associated to. For example if the determined HARQ codeword is <NUM>, the terminal device will transmit on PUCCH #<NUM> resource as shown in <FIG>.

In another embodiment shown in <FIG> HARQ bundeling follows another mapping where a PUCCH resource is saved compared to <FIG>. This is achieved by, for a given number Q of HARQ processes a number <NUM>^N-<NUM> of PUCCH resources are reserved, where Q>N, both are positive integer numbers. The possible HARQ feedback codewords alternatives (e.g. <NUM>, <NUM>, etc) are grouped (bundled) so that (<NUM>^Q / <NUM>^N) codewords are associated to each PUCCH resource except for one PUCCH resource. The codewords of one group may differ by up to Q-N bit with the exception of one group where the codewords may differ by up to Q-N+<NUM> bit.

In the example shown in <FIG> the following parameters are used: Q=<NUM> and N=<NUM>. <NUM> NACK codewords (<NUM> needs not to be coded) are associated to the PUCCH resources. <NUM>^N-<NUM>=<NUM> PUCCH resources are available. Bundling size is <NUM>^Q/<NUM>^N=<NUM> for <NUM> of the codewords (associated to PUCCH #<NUM>-#<NUM>) and <NUM> for <NUM> of the codewords (associated to PUCCH #<NUM>). A "<NUM>" in the codeword signifies a NACK. All zero codeword (<NUM>) is not sent. The codewords of the groups mapped to PUCCH #<NUM>-#<NUM> differ by Q-N=<NUM>-<NUM>=<NUM> bit, while the codewords mapped to PUCCH #<NUM> differ by up to Q-N+<NUM>=<NUM>-<NUM>+<NUM>=<NUM> bits.

In still another embodiment HARQ bundling follows a mapping where codewords representing only few NACKs are mapped to different PUCCH resources, and codewords representing more NACKs are grouped and mapped to the same PUCCH resource. In other words, codewords may be associated to the PUCCH resources based on the number of NACKs coded into the HARQ codeword.

An example of such an embodiment is shown in <FIG> with the same parameters (Q=<NUM> and N=<NUM>) as used for the example shown in <FIG>.

In the example shown in <FIG> the HARQ feedback for the Q=<NUM> HARQ processes is mapped to the <NUM>^N PUCCH resources in such a way, that the first PUCCH#<NUM>-#<NUM> resources are associated with the codewords representing maximum <NUM> NACKs (codeword weight of max. <NUM>), while PUCCH#<NUM> resource is associated with codewords representing <NUM> or more NACKs (codeword weight of <NUM> or higher). The all-zero codeword is not mapped to any PUCCH resource. The weight of a codeword is the number of "<NUM>" (NACKs) present in the codeword.

The motivation for the above embodiment is twofold;.

In one embodiment, the gNB configures N PUCCH format <NUM> resources in a slot. Each resources is associated with one HARQ process and can be addressed e.g. by the PRI in the PTM-DCI.

The UE transmits a PUCCH format <NUM> NACK signal on the resource if the corresponding HARQ process indicated PDSCH decoding failure. If the UE is configured with multiple PUCCH resources for NACK signals and has failed to decode in multiple HARQ processes then the UE needs to transmit multiple NACK signals in the same slot.

In one embodiment the multiple PUCCH resources in a slot may be preferably configured on different OFDM symbols, so that the UE does not need to share its total transmit power among multiple NACK signals.

With second priority multiple PUCCH resources may be configured on the same OFDM symbol, i.e. using multiple PRBs. In one embodiment multiple PUCCH resources are configured on adjacent PRBs. This has the advantage of causing less intermodulation problems in the UE transmitter chain. According to TS <NUM> V17. <NUM> resource allocation for PUSCH using CP-OFDM has to be almost-contiguous in FR1 (frequency range <NUM>), where almost means the gaps must be smaller than <NUM>% of the PRB range including both gaps and allocated PRBs, and in FR2 (frequency range <NUM>) the allocation for PUSCH has to be contiguous.

For PUSCH the allocated PRB are also actually used for transmission. Multiple PUCCH resources configured for possible NACK transmission are, however, in general not all used by a UE. Therefore, even if the PUCCH resources are configure adjacently, the PRBs used for transmission of NACK signals by a UE in a particular slot will in general not be contiguous or almost-contiguous.

If the intermodulation problem in the transmitter is of lower importance, then in one embodiment the PRBs are configured non-adjacent. This has the advantage that possible signal distortion problems in the gNB receiver that can lead to interference between PRBs has decreases impact. Such signal distortion may be caused by an excessively high level of the accumulation of the power received from the unknown number of group UEs transmitting a NACK signal on the same PUCCH resource.

In one embodiment the multiple phase and reference rotations of the sequence that constitutes the PUCCH format <NUM> signal are exploited for forming NACK signal. There are <NUM> different rotations that can be multiplexed in one PUCCH format <NUM> resource. The rotations may be regarded as an additional multiplexing domain, i.e. in addition to the OFDM symbol and PRB domain introduced in previous embodiments.

In Rel-<NUM> at most <NUM> rotations are allocated for representing <NUM> HARQ ACK/NACK bits per UE and different rotations can be used by different UEs to transmit ACK/NACK bits on the same PUCCH OFDM-symbol and PRB. For PTM and NACK-only signalling, all <NUM> rotations can be configured for all group-UEs. A drawback is that the UE has to split its total power over the rotations it uses.

The gNB for each PUCCH OFDM-symbol and PRB performs correlation of the received signal with the <NUM> rotations of the base sequence and then performs energy detection separately on each of the <NUM> correlation signals to determine if at least one group-UE has transmitted a signal with the corresponding rotation.

The misdetection probability at the gNB (the network node) for adjacent rotations increases with the channel delay spread. A known practically solution to keep the misdetection probability below an acceptable level is to not use each of the rotations (i.e. the <NUM> rotations), but only every other rotation.

Another possible solution is to minimize the effect that a misdetection between adjacent rotations can have. This may be done as described in the following embodiment.

In one embodiment each codeword is mapped to a different rotation using "Gray" encoding, so that any <NUM> adjacent rotations correspond to <NUM> codewords that differ only in <NUM> bit.

<FIG> shows an example of a <NUM>-bit codeword of a UE (terminal device) mapped to <NUM> different rotations following the Gray encoding. Each bit is represented by the values N for NACK (i.e. "<NUM>") or A for ACK (i.e. "<NUM>"). This scheme can be extended to codewords with more than <NUM> bits.

<FIG> shows an embodiment with <NUM> rotations supporting log2(<NUM>)=<NUM> bit codewords. Different rotations can be configured to represent different decoding results for <NUM> HARQ processes. The decoding results of adjacent rotations only differ by one bit (Gray encoding).

If some codewords are mapped to the same rotation (not shown), even codewords with more than <NUM> bits can be supported when assuming for example <NUM> rotations in total. Multiple HARQ codewords may be associated to the same phase rotation based on the number of NACKs coded into the HARQ codeword.

In one embodiment, one PUCCH resource for format <NUM> is configured for multiple HARQ processes, and each UE transmits a NACK signal on the PUCCH resource if decoding failure in any of the HARQ processes has occurred. The gNB when receiving a NACK signal on the PUCCH resource will retransmit all transport blocks corresponding to the HARQ processes.

In a related embodiment, the total set of HARQ processes for which a transport block needs to be decoded and for which a UE must have the opportunity to indicate NACK to the UE is split into multiple subsets. For each subset the UE will transmit NACK if any decoding for any of the HARQ processes in the subset has failed. For each subset the gNB configures a PUCCH resource. The multiple PUCCH resources may be configured in a way in terms of OFDM symbol, PRB and rotation allocation as described in embodiments above.

According to such embodiments of the present disclosure, the problem of signaling NACK-only for a set of HARQ processes in one uplink slot may be solved, wherein multiple UEs use the same PUCCH resource for the NACK-only signal relating to the same subset of HARQ processes, and the subset size may reduce to <NUM> (namely, for each HARQ process).

<FIG> is a block diagram illustrating apparatuses for a network node, a terminal device, according to embodiments of the present disclosure.

As shown in <FIG>, a terminal device <NUM> may comprise: one or more processors <NUM>; and one or more memories <NUM> comprising computer program codes <NUM>. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the terminal device at least to: perform the method according to any of embodiments above described.

A network node <NUM> may comprise: one or more processors <NUM>; and one or more memories <NUM> comprising computer program codes <NUM>. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the network node at least to: perform the method according to any of embodiments above described.

The processors <NUM>, <NUM>, may be any kind of processing component, such as one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The memories <NUM>, 2002may be any kind of storage component, such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc..

<FIG> is a block diagram illustrating a computer-readable medium <NUM> according to some embodiments of the present disclosure.

As shown in <FIG>, there is provided a computer-readable medium <NUM> having computer program codes <NUM> embodied thereon for use with one of a network node <NUM> and a terminal device <NUM>. The computer program codes may comprise codes for performing the method according to any one of embodiments above described. The computer program codes <NUM> may include or correspond to these computer program codes <NUM>, <NUM>.

The computer readable storage medium <NUM> may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives.

<FIG> is a block diagram illustrating apparatuses for the network node (e.g. a base station), terminal device, according to some embodiments of the present disclosure.

As shown in <FIG>, there is provided a terminal device <NUM>, comprising: a transmitting unit <NUM>, configured to perform step S101.

In embodiments of the present disclosure, the terminal device may perform the method according to any of embodiments above described.

As shown in <FIG>, there is provided a network node <NUM>, comprising: a receiving unit <NUM>, configured to perform step S201.

In embodiments of the present disclosure, the network node may perform the method according to any of embodiments above described.

With these units, the terminal device <NUM>, the network node <NUM> may not need a fixed processor or memory, any computing resource and storage resource may be arranged from at least one network node/device/entity/apparatus in the communication system. The virtualization technology and network computing technology may be further introduced, so as to improve the usage efficiency of the network resources and the flexibility of the network.

These embodiments of the present disclosure may be implemented in a communication system.

For example, there is provided a method implemented in a communication system which may include a host computer, a network node and a UE. The network node may be the network node <NUM> of <FIG> and <FIG> which may perform the method S201 of <FIG>. The network node is referred in the following paragraphs as base station. The UE may be the terminal device <NUM> of <FIG> and <FIG> which may perform the method S101 of <FIG>.

The method may comprise providing user data at the host computer. Optionally, the method may comprise, at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station which may perform any step of the method according to above embodiments of the present disclosure.

For example, there is provided a communication system including a host computer. The host computer may comprise processing circuitry configured to provide user data, and a communication interface configured to forward the user data to a cellular network for transmission to a UE. The cellular network may comprise a base station having a radio interface and processing circuitry. The base station's processing circuitry may be configured to perform any step of the method according to the above embodiments of the present disclosure.

For example, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise providing user data at the host computer. Optionally, the method may comprise, at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station. The UE may perform any step of the method according to the above embodiments of the present disclosure.

For example, there is provided a communication system including a host computer. The host computer may comprise processing circuitry configured to provide user data, and a communication interface configured to forward user data to a cellular network for transmission to a UE. The UE may comprise a radio interface and processing circuitry. The UE's processing circuitry may be configured to perform any step of the method according to the above embodiments of the present disclosure.

For example, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise, at the host computer, receiving user data transmitted to the base station from the UE which may perform any step of the method according to the above embodiments of the present disclosure.

For example, there is provided a communication system including a host computer. The host computer may comprise a communication interface configured to receive user data originating from a transmission from a UE to a base station. The UE may comprise a radio interface and processing circuitry. The UE's processing circuitry may be configured to perform any step of the method according to the above embodiments of the present disclosure.

For example, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise, at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE. The base station may perform any step of the method according to the above embodiments of the present disclosure.

For example, there is provided a communication system which may include a host computer. The host computer may comprise a communication interface configured to receive user data originating from a transmission from a UE to a base station. The base station may comprise a radio interface and processing circuitry. The base station's processing circuitry may be configured to perform any step of the method according to the above embodiments of the present disclosure.

<FIG> is a block diagram illustrating a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments of the present disclosure.

With reference to <FIG>, in accordance with an embodiment, a communication system includes a telecommunication network <NUM>, such as a 3GPP-type cellular network, 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 base stations 912a, 912b, 912c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 913a, 913b, 913c. Each base station 912a, 912b, 912c is connectable to the core network <NUM> over a wired or wireless connection <NUM>. Network node <NUM> of <FIG> and <FIG> may represent a base station. A first UE <NUM> located in a coverage area 913c is configured to wirelessly connect to, or be paged by, the corresponding base station 912c. A second UE <NUM> in a coverage area 913a is wirelessly connectable to the corresponding base station 912a. Terminal device <NUM> of <FIG> and <FIG> may represent a UE.

An intermediate network <NUM> may be one of, or a combination of more than one of, a public, private or hosted network; the intermediate network <NUM>, if any, may be a backbone network or the Internet; in particular, the intermediate network <NUM> may comprise two or more sub-networks (not shown).

The connectivity may be described as an overthe-top (OTT) connection <NUM>.

<FIG> is a block diagram illustrating a host computer communicating via a base station with a UE over a partially wireless connection in accordance with some embodiments of the present disclosure.

The host computer <NUM> further comprises a processing circuitry <NUM>, which may have storage and/or processing capabilities. The host application <NUM> may be operable to provide a service to a remote user, such as UE <NUM> connecting via an OTT connection <NUM> terminating at the UE <NUM> and the host computer <NUM>.

In the embodiment shown, the hardware <NUM> of the base station <NUM> further includes a processing circuitry <NUM>, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions.

The hardware <NUM> of the UE <NUM> further includes a processing circuitry <NUM>, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions.

It is noted that the host computer <NUM>, the base station <NUM> and the UE <NUM> illustrated in <FIG> may be similar or identical to the host computer <NUM>, one of base stations 912a, 912b, 912c and one of UEs <NUM>, <NUM> of <FIG>, respectively.

In <FIG>, the OTT connection <NUM> has been drawn abstractly to illustrate the communication between the host computer <NUM> and the UE <NUM> via the base station <NUM>, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

Wireless connection <NUM> between the UE <NUM> and the base station <NUM> is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE <NUM> using the OTT connection <NUM>, in which the wireless connection <NUM> forms the last segment. More precisely, the teachings of these embodiments may improve the latency and the power consumption, and thereby provide benefits such as lower complexity, reduced time required to access a cell, better responsiveness, extended battery lifetime, etc..

The measurement procedure and/or the network functionality for reconfiguring the OTT connection <NUM> may be implemented in software <NUM> and hardware <NUM> of the host computer <NUM> or in software <NUM> and hardware <NUM> of the UE <NUM>, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection <NUM> passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which the software <NUM>, <NUM> may compute or estimate the monitored quantities. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer <NUM>'s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that the software <NUM> and <NUM> causes messages to be transmitted, in particular empty or 'dummy' messages, using the OTT connection <NUM> while it monitors propagation times, errors etc..

<FIG> is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment.

<FIG> is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment.

<FIG> is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment.

<FIG> is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment.

In general, the various exemplary embodiments may be implemented in hardware or special purpose chips, circuits, software, logic or any combination thereof.

It should be appreciated that at least some aspects of the exemplary embodiments of the disclosure may be embodied in computer-executable instructions, such as in one or more program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types when executed by a processor in a computer or other device. The computer executable instructions may be stored on a computer readable medium such as a hard disk, optical disk, removable storage media, solid state memory, random access memory (RAM), etc. As will be appreciated by one of skill in the art, the function of the program modules may be combined or distributed as desired in various embodiments. In addition, the function may be embodied in whole or partly in firmware or hardware equivalents such as integrated circuits, field programmable gate arrays (FPGA), and the like.

The present disclosure includes any novel feature or combination of features disclosed herein either explicitly or any generalization thereof. Various modifications and adaptations to the foregoing exemplary embodiments of this disclosure may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings.

Claim 1:
A method performed by a terminal device (<NUM>), comprising:
transmitting (S101), to a network node (<NUM>), information about acknowledgement, based on a configuration of a resource for the information about acknowledgement;
wherein the resource is configured for at least one Hybrid Automatic Repeat reQuest, HARQ, process;
wherein the configuration indicates using multiple Physical Uplink Control Channel, PUCCH, resources in a slot;
wherein the multiple PUCCH resources include M = <NUM>^N - <NUM> PUCCH resources for N HARQ processes, wherin M is positive integer and N is positive integer larger than <NUM>; and
wherein the terminal device (<NUM>) transmits on one of the PUCCH resources according to a subset of HARQ processes for which the terminal device (<NUM>) needs to signal NACK; and
wherein the terminal device (<NUM>) transmits on at least one PUCCH resource of the multiple PUCCH resources if the terminal device (<NUM>) has at least one NACK, and the terminal device (<NUM>) does not transmit on the multiple PUCCH resources if the terminal device (<NUM>) does not have a NACK.