CN112740600A

CN112740600A - Method and apparatus

Info

Publication number: CN112740600A
Application number: CN201880097756.9A
Authority: CN
Inventors: 晁华; 杨莉
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Oyj
Priority date: 2018-09-19
Filing date: 2018-09-19
Publication date: 2021-04-30
Anticipated expiration: 2038-09-19
Also published as: WO2020056645A1; CN112740600B

Abstract

A method includes selecting a plurality of resources from a common pool of resources available to a plurality of communication devices. Different ones of the resources are used to transmit respective copies of the first packet. Causing a first copy of the first packet to be transmitted from the first communication device to the base station. A first copy of the first packet is transmitted on a first resource of the plurality of resources. The method includes receiving feedback from a base station in a first feedback resource related to a first resource.

Description

Method and apparatus

Technical Field

The present disclosure relates to communications, and more particularly, to methods and apparatus in a wireless communication system.

Background

A communication system may be seen as a facility that enables communication sessions between two or more entities, such as user terminals, base stations/access points and/or other nodes, by providing carriers between the various entities involved in a communication path. For example, a communication system may be provided by means of a communication network and one or more compatible communication devices. The communication session may include, for example, communication of data for carrying communications such as voice, electronic mail (email), text messages, multimedia and/or content data. Non-limiting examples of services provided include two-way or multi-way calls, data communication or multimedia services, and access to data network systems such as the internet.

Disclosure of Invention

According to a first aspect, there is provided a method comprising: selecting a plurality of resources from a common pool of resources available to a plurality of communication devices, different ones of the resources being used to transmit respective copies of a first packet; causing a first copy of a first packet to be transmitted from a first communication device to a base station, the first copy of the first packet being transmitted on a first resource of the plurality of resources; and receiving feedback from the base station in a first feedback resource, the first feedback resource relating to the first resource.

Thus, in some embodiments, there may be a one-to-one mapping between the resource and the first feedback resource. In some embodiments, the feedback may be based on each common resource rather than each communication device.

The resources for transmitting the respective copies of the first packet may be provided by one or more resource units in a common resource pool.

In some embodiments, two or more copies of the first packet may be transmitted.

The method can comprise the following steps: in response to not receiving an acknowledgement in the first feedback resource for the first communication device, monitoring a second feedback resource for acknowledgement information associated with a first copy of a packet.

The second feedback resource may be provided within a window.

The method can comprise the following steps: in response to not receiving an acknowledgement in the first feedback resource for the first communication device, causing a second copy of the first packet to be transmitted using a second resource of the plurality of resources.

The second copy of the first packet is transmitted only when an acknowledgement for the first communication device is not received in the second feedback resource and the first feedback resource.

The feedback in the first feedback resource comprises negative acknowledgements for a plurality of communication devices selecting a first resource in a common resource pool.

This may indicate that there is no acknowledgement for any of the plurality of communication devices selecting the first resource in the common resource pool.

The negative acknowledgement may indicate a decoding failure of a packet from a plurality of communication devices selecting the first resource in the common resource pool.

The feedback in the first feedback resource comprises an acknowledgement to a different communication device of the plurality of communication devices.

This may indicate that there is no acknowledgement for the first communication device in the first feedback resource.

When the corresponding copy of the first packet has been sent, other copies of the first packet may be left untransmitted.

The feedback in the first feedback resource is an acknowledgement to the first communication device and, in response, the other copy of the first packet is not transmitted.

The selecting may include selecting a defined number of resources corresponding to a defined number of copies of the first grouping.

The method may include monitoring a first feedback resource.

The respective feedback resources may have a predefined timing and/or frequency relationship with respect to the respective resources in the common resource pool.

The respective feedback resources may be provided k time slots after the respective resources in the common resource pool. The value of k may be configured by the base station.

The method may include receiving information from a base station indicating respective first feedback resources to be monitored and respective second feedback resources to be monitored.

The information on the first feedback resource and the second feedback resource may be transmitted together or separately.

The method may be performed by an apparatus. The apparatus may be provided in a user equipment.

According to another aspect, there is provided a method comprising: causing a first copy of the first packet to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource in the common resource pool; monitoring a first feedback resource associated with the first resource to monitor for acknowledgements associated with the first communication device; and if no acknowledgement is received for the first communication, causing a second feedback resource within a second feedback window to be monitored.

According to another aspect, there is provided a method comprising: causing information to be transmitted to a plurality of communication devices, the information indicating a first feedback resource to be monitored and a second feedback resource to be monitored; determining a decoding failure for a first resource in a common resource pool, the common resource pool available to the plurality of communication devices, the decoding failure being a result of a plurality of packets from the plurality of communication devices being transmitted in the first resource; and causing a negative acknowledgement to be transmitted in a first feedback resource related to the first resource, the negative acknowledgement being for the first resource in the common resource pool.

Thus, in some embodiments, there may be a one-to-one mapping between resources in the common resource pool and the first feedback resource. In some embodiments, the feedback is based on each common resource rather than each communication device.

The first resource may be provided by one or more resource units in a common resource pool.

The first feedback resource may have a predefined timing and/or frequency relationship with respect to the first resource.

The first feedback resource may be provided k slots after the first resource. The value of k may be configured by the base station.

The method may include successfully decoding a second copy of the first packet, the second copy of the first packet received from a first communication device of the plurality of communication devices in a second resource of the common resource pool, and removing the first copy of the first packet from the plurality of packets, the plurality of packets received from the plurality of communication devices in the first resource.

The method can include determining whether a second packet of the plurality of packets received from a second communication device of the plurality of communication devices in the first resource after removing the first packet is decodable, and if so, decoding the second packet and causing acknowledgement information to be transmitted on the second feedback resource.

The second feedback resource may be defined relative to the first resource and may be later than the first feedback resource.

The method may include configuring a size of the common resource pool.

At least one communication device may be in an idle state.

The method may be performed by an apparatus. The apparatus may be provided in a base station.

According to another aspect, there is provided an apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured, with the at least one processor, to cause the apparatus at least to: selecting a plurality of resources from a common pool of resources available to a plurality of communication devices, different ones of the resources being used to transmit respective copies of the first packet; causing a first copy of the first packet to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource of the plurality of resources; and receiving feedback from the base station in a first feedback resource, the first feedback resource being related to the first resource.

In some embodiments, two or more copies of the first packet may be transmitted.

The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: in response to not receiving an acknowledgement in the first feedback resource for the first communication device, monitoring a second feedback resource for acknowledgement information associated with the first copy of the packet.

The second feedback resource may be provided within a window.

The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: in response to not receiving an acknowledgement in the first feedback resource for the first communication device, causing a second copy of the first packet to be transmitted using a second resource of the plurality of resources.

The feedback in the first feedback resource comprises negative acknowledgements for the plurality of communication devices selecting the first resource in the common resource pool.

This may indicate that there is no acknowledgement for any of the plurality of communication devices that selected the first resource in the common resource pool.

The negative acknowledgement may indicate a decoding failure of the packet from the plurality of communication devices selecting the first resource in the common resource pool.

The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: a defined number of resources corresponding to the defined number of copies of the first packet is selected.

The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: a first feedback resource is monitored.

The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: information is received from a base station, the information indicating respective first feedback resources to be monitored and respective second feedback resources to be monitored.

According to another aspect, there is provided an apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured, with the at least one processor, to cause the apparatus at least to: causing a first copy of the first packet to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource in the common resource pool; monitoring a first feedback resource associated with the first resource to monitor for acknowledgements associated with the first communication device; and if no acknowledgement is received for the first communication, causing a second feedback resource within a second feedback window to be monitored.

According to another aspect, there is provided an apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured, with the at least one processor, to cause the apparatus at least to: causing information to be transmitted to a plurality of communication devices, the information indicating a first feedback resource to be monitored and a second feedback resource to be monitored; determining a decoding failure for a first resource in a common resource pool, the common resource pool being available to a plurality of communication devices, the decoding failure being a result of a plurality of packets from the plurality of communication devices being transmitted in the first resource; and causing a negative acknowledgement to be transmitted in a first feedback resource related to the first resource, the negative acknowledgement being for the first resource in the common resource pool.

The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: the method further includes successfully decoding a second copy of the first packet, the second copy of the first packet received from a first communication device of the plurality of communication devices in a second resource of the common resource pool, and removing the first copy of the first packet from the plurality of packets, the plurality of packets received from the plurality of communication devices in the first resource.

The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: determining whether a second packet of the plurality of packets received from a second communication device of the plurality of communication devices in the first resource after removing the first packet is decodable, and if so, decoding the second packet and causing acknowledgement information to be transmitted on the second feedback resource.

The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to: the size of the common resource pool is configured.

At least one communication device may be in an idle state.

According to another aspect, there is provided an apparatus comprising means for: selecting a plurality of resources from a common pool of resources available to a plurality of communication devices, different ones of the resources being used to transmit respective copies of the first packet; causing a first copy of the first packet to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource of the plurality of resources; and receiving feedback from the base station in a first feedback resource, the first feedback resource being related to the first resource.

In some embodiments, two or more copies of the first packet may be transmitted.

These components may be: in response to not receiving an acknowledgement in the first feedback resource for the first communication device, monitoring a second feedback resource for acknowledgement information associated with the first copy of the packet.

The second feedback resource may be provided within a window.

These components may be: in response to not receiving an acknowledgement in the first feedback resource for the first communication device, causing a second copy of the first packet to be transmitted using a second resource of the plurality of resources.

These components may be used to select a defined number of resources corresponding to a defined number of copies of the first packet.

These components may be used to monitor the first feedback resource.

The components may be configured to receive information from a base station, the information indicating respective first feedback resources to be monitored and respective second feedback resources to be monitored.

The apparatus may be provided in a user equipment.

According to another aspect, there is provided an apparatus comprising means for: causing a first copy of the first packet to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource in the common resource pool; monitoring a first feedback resource associated with the first resource to monitor for acknowledgements associated with the first communication device; and if no acknowledgement is received for the first communication, causing a second feedback resource within a second feedback window to be monitored.

The apparatus may be provided in a user equipment.

According to another aspect, there is provided an apparatus comprising means for: causing information to be transmitted to a plurality of communication devices, the information indicating a first feedback resource to be monitored and a second feedback resource to be monitored; determining a decoding failure for a first resource in a common resource pool, the common resource pool being available to a plurality of communication devices, the decoding failure being a result of a plurality of packets from the plurality of communication devices being transmitted in the first resource; and causing a negative acknowledgement to be transmitted in a first feedback resource related to the first resource, the negative acknowledgement being for the first resource in the common resource pool.

The components may be configured to successfully decode a second copy of the first packet, the second copy of the first packet received from a first communication device of the plurality of communication devices in a second resource of the common resource pool, and remove the first copy of the first packet from the plurality of packets, the plurality of packets received from the plurality of communication devices in the first resource.

The components may be configured to determine whether a second packet of the plurality of packets received from a second communication device of the plurality of communication devices in the first resource is decodable after removing the first packet, and if so, decode the second packet and cause acknowledgement information to be transmitted on the second feedback resource.

These components may be used to configure the size of the common resource pool.

At least one communication device may be in an idle state.

The apparatus may be provided in a base station.

An apparatus may comprise means for performing the acts of the method as above.

An apparatus may be configured to perform the acts of the above method.

In another aspect, a non-transitory computer-readable medium is provided that includes program instructions thereon for performing at least the following: selecting a plurality of resources from a common pool of resources available to a plurality of communication devices, different ones of the resources being used to transmit respective copies of the first packet; causing a first copy of the first packet to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource of the plurality of resources; and receiving feedback from the base station in a first feedback resource, the first feedback resource being related to the first resource.

In another aspect, a non-transitory computer-readable medium is provided that includes program instructions thereon for performing at least the following: causing a first copy of the first packet to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource in the common resource pool; monitoring a first feedback resource associated with the first resource to monitor for acknowledgements associated with the first communication device; and if no acknowledgement is received for the first communication, causing a second feedback resource within a second feedback window to be monitored.

In another aspect, a non-transitory computer-readable medium is provided that includes program instructions thereon for performing at least the following: causing information to be transmitted to a plurality of communication devices, the information indicating a first feedback resource to be monitored and a second feedback resource to be monitored; determining a decoding failure for a first resource in a common resource pool, the common resource pool being available to a plurality of communication devices, the decoding failure being a result of a plurality of packets from the plurality of communication devices being transmitted in the first resource; and causing a negative acknowledgement to be transmitted in a first feedback resource related to the first resource, the negative acknowledgement being for the first resource in the common resource pool.

According to another aspect, there is provided a computer program comprising computer executable code which, when run on at least one processor, is configured to: selecting a plurality of resources from a common pool of resources available to a plurality of communication devices, different ones of the resources being used to transmit respective copies of the first packet; causing a first copy of the first packet to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource of the plurality of resources; and receiving feedback from the base station in a first feedback resource, the first feedback resource being related to the first resource.

According to another aspect, there is provided a computer program comprising computer executable code which, when run on at least one processor, is configured to: causing a first copy of the first packet to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource in the common resource pool; monitoring a first feedback resource associated with the first resource to monitor for acknowledgements associated with the first communication device; and if no acknowledgement is received for the first communication, causing a second feedback resource within a second feedback window to be monitored.

According to another aspect, there is provided a computer program comprising computer executable code which, when run on at least one processor, is configured to: causing information to be transmitted to a plurality of communication devices, the information indicating a first feedback resource to be monitored and a second feedback resource to be monitored; determining a decoding failure for a first resource in a common resource pool, the common resource pool being available to a plurality of communication devices, the decoding failure being a result of a plurality of packets from the plurality of communication devices being transmitted in the first resource; and causing a negative acknowledgement to be transmitted in a first feedback resource related to the first resource, the negative acknowledgement being for the first resource in the common resource pool.

The computer program may comprise program instructions for causing a computer to perform the method as above.

A computer program product stored on a medium may cause an apparatus to perform the methods described herein.

An electronic device may comprise an apparatus as described herein.

A chipset may comprise the apparatus described herein.

In the above, various aspects are described. It should be understood that other aspects may be provided by a combination of any two or more of the above aspects.

Various other aspects and other embodiments are also described in the following detailed description and the appended claims.

Drawings

To assist in understanding the present disclosure and to show how some embodiments may be carried into effect, reference is made, by way of example only, to the accompanying drawings, in which:

fig. 1 schematically shows an example of a communication network;

figure 2 schematically shows an example of a mobile communication device;

fig. 3 schematically shows an example of the control device.

FIG. 4 shows a signal flow;

fig. 5 illustrates allocation of an unlicensed access request of a communication device to a pool of common resource units;

FIG. 6 illustrates acknowledgement provided by a base station of a request for resources;

fig. 7 shows a method flow in an apparatus of a communication device;

fig. 8 shows a method flow in an arrangement of a base station;

fig. 9 shows a further method flow in the arrangement of the communication device:

fig. 10 shows another method flow in an apparatus of a communication device.

Detailed Description

Before explaining the examples in detail, some general principles of wireless communication systems and mobile communication devices are briefly explained with reference to fig. 1 to 3 to help understand the techniques behind the described examples.

Fig. 1 schematically shows a system 600 of networks and communication devices. The communication device may be a user equipment, UE. The network includes a base station. It should be understood that in a so-called 5G network, a base station may be referred to as a gNB (next generation NodeB). In other examples, the base station may be referred to as an eNB. The network supports a first communication device 605, a second communication device 607, and a third communication device 609, all of which are within network coverage. In the presently illustrated example, all of the

communication devices

605, 607, 609 are within the coverage of the gNB 601, but in some embodiments one or more of the

communication devices

605, 607, 609 are mobile and thus can move into and out of the coverage of the gNB 601. Other communication devices not shown in fig. 6 may move into the coverage of the gNB 601.

As will be discussed in more detail, some embodiments allow the

communication devices

605, 607, 609 to perform an unlicensed uplink transmission to the gNB 601.

The communication device will now be described in more detail with reference to fig. 2, which fig. 2 shows a schematic, partly sectional view of a communication device 700. Such a communication device may be, for example, a mobile device (e.g., User Equipment (UE)), i.e., a device that is not fixed to a particular location, or it may be a fixed device. Wireless devices may or may not require human interaction to communicate. The latter device is sometimes referred to as an MTC (machine type communication) device (e.g., a sensor). Such a device may have only a subset of the components shown in fig. 2 and/or a simplified version of the components. In the present teachings, the term communication device is used to refer to any type of wireless communication device.

Suitable communication devices may be provided by any device capable of sending and receiving radio signals. Non-limiting examples include a Mobile Station (MS) or mobile device such as a mobile phone or known 'smart phone', a computer equipped with a wireless interface card or other wireless interface facility (e.g., a USB dongle), a Personal Digital Assistant (PDA) or tablet computer equipped with wireless communication capabilities, a machine type communication device, or any combination of these or similar devices.

The communication device 700 may receive signals over the air or radio interface via suitable means for receiving and may transmit signals via suitable means for transmitting radio signals. In fig. 2, the transceiver apparatus is schematically designated by block 706. The transceiver means 706 may be provided, for example, by a radio part and associated antenna arrangement. The antenna arrangement may be arranged inside or outside the communication device.

A communication device is typically provided with at least one data processing entity 701, at least one memory 702 and possibly other components 703 for software and hardware assisted execution of tasks it is designed to perform, including control of access and communication to access systems and other communication devices. The data processing, storage and other related control means may be provided on a suitable circuit board and/or in a chipset. This feature is denoted by reference numeral 704. In some embodiments, the communication device may comprise an apparatus. The apparatus may comprise one or more of at least one data processing entity, such as a processor, and at least one memory.

The user may control the operation of the mobile device through a suitable user interface, such as a keyboard 705, voice commands, a touch sensitive screen or pad, combinations thereof, and the like. In some embodiments, this may be optional.

A display 708, a speaker, and a microphone may also be provided. One or more of these components may be optional.

An exemplary apparatus is shown in fig. 3. The apparatus 800 comprises at least one memory 801, at least one

data processing unit

802, 803 and an input/output interface 804. The apparatus 800 or processor 802/803 may be configured to execute appropriate software code to provide control functions. The

processors

802, 803 may perform functions associated with the operation of the apparatus 800. In some examples, the at least one memory 801 stores software modules that provide functionality when executed by the

processors

802, 803. The modules may include an operating system that provides operating system functionality for the device 800. The components of the apparatus 800 may be implemented in hardware, or as any suitable combination of hardware and software.

The apparatus 800 may be disposed in an access point. In an example, the access point can be a base station, such as a gbb in the case of a 5G system.

According to some example embodiments, one or more of the blocks or functions shown in fig. 2 or 3 may be implemented as a chip (integrated circuit), a chipset, or one or more dies.

As will now be explained in more detail, some embodiments relate to a 5g (nr) system. However, it should be understood that some embodiments may be used with any other suitable communication standard. Some embodiments may also be applicable to future LTE releases or other communication standards.

In the 5G NR (new air interface) access technology, an access based on an unlicensed uplink UL is proposed. Grant-free based UL non-orthogonal Multiple Access (MA) has been defined as a transmission from a communication device that may not require dynamic and explicit scheduling grants from the gNB.

A grant-free transmission scheme based on a primary RACH (random access channel) has been proposed. This scheme is proposed for mtc (large scale machine type communication) for low latency and small data transmission. Referring to fig. 4, a signaling flow between a communication device 605 and a base station 601 is shown.

For MA resources used for unlicensed transmission, it has been proposed that the MA physical resources used for "unlicensed" UL transmission consist of time-frequency blocks. The MA resource is composed of an MA physical resource and an MA signature. Since more than one UE may select the same MA physical resource in the resource pool for UL data transmission, a collision will occur. The MA signature is used to detect collisions.

In the signaling flow of fig. 4, the communication device transmits the MA signature and data to the base station in step 1. This will be transmitted on the selected MA physical resource.

Assuming that the MA signature and data are received by the gNB, the gNB will provide feedback to the communication device in step 2.

An example of a resource pool is shown in FIG. 5. The resource pool is shown as a frequency versus time graph. The frequencies are divided into M blocks, M to M + M. Time is divided into N blocks, N to N + N. N and M are both integers. In some embodiments, m and n may be 1. N and M may have any suitable values. This provides N x M Resource Units (RUs), where a resource unit is a resource block at a given frequency block and a given time block.

To improve transmission efficiency in some cases, time-frequency repetition or so-called diversity transmission is proposed to allow a communication device to send more than one copy of the same packet in different MA physical resources.

Some embodiments may address the situation where the user equipment randomly selects MA physical resources and the gNB does not have a priori information about the selected MA physical resources.

Fig. 5 shows an example where each communication device transmits each packet with two copies. These two element sets F, T represent a certain MA physical Resource Unit (RU). F is the frequency domain index within the resource pool and T is the time domain index. The first communication device UE1 sends the first packet in { m +2, n } as the second communication device UE 2. The UE1 sends the second packet, and the third communication device UE3 and the fourth communication device UE4 send the first packet in { m +3, n +2 }. The UE2 sends the second packet in { m +4, n +3 }. The UE3 sends the second packet in { m +1, n +4 }. UE2 and UE4 send a second packet in { m, n +5 }.

In the gNB, successive interference cancellation, SIC, across multiple slots is used to remove duplicates of already recovered transmissions from colliding slots. Although any copy of the same packet may collide, recovery is possible. The recovery and removal operations may be performed in a continuous manner. For example, when the first copy of UE2 is recovered and removed after correctly decoding the second copy of UE2 in { m +4, n +3}, the first copy of UE1 in the { m +2, n } slot may be recovered. Then, the first copy of UE4 in { m +3, n +2} may be recovered after the second copy of UE1, and the first copy of UE3 may be recovered and removed after correctly decoding the first copy of UE1 in { m +2, n } and correctly decoding the second copy of UE3 in { m +1, n +4 }.

It should be appreciated that if the gNB recovers one copy of a certain packet in the MA physical resources, it can know the MA physical resources occupied by another copy of the packet.

The communication device may select a different MA physical resource for transmission of the signal packet. The gbb may decode using the SIC receiver. In contrast to techniques that do not use diversity, the success or failure of a single packet may depend on the decoding results of other copies and may affect the decoding results of other packets.

Some embodiments may address the issue of the UE knowing when and/or where to receive hybrid automatic repeat request, HARQ, feedback or other feedback for each packet.

In some proposals, assuming synchronous HARQ is applied to the UL, HARQ has a fixed feedback timing definition. In this scenario, when a communication device selects a first MA physical resource in, for example, { F1, T1} and a second MA physical resource in { F2, T2}, the first slot in which it may receive HARQ feedback is T1+ k, where k is the timing between the HARQ feedback and its corresponding UL data. For unlicensed transmissions with diversity, such fixed HARQ timing may be disadvantageous in certain scenarios. A communication device may not know whether a collision has occurred between itself and other communication devices participating in an unlicensed transmission in the same resource pool. Thus, if the communication device does not receive an acknowledgement ACK in time slot T1+ k, the communication may not know when to detect other feedback and when it may receive an ACK in a subsequent time slot. This may result in unnecessary retransmission of the packet.

In some proposals, the HARQ feedback resources used to provide the acknowledgement may depend on the state of the communication device. For example, the communication device radio resource control, RRC, is connected or not.

In some proposals, for RRC idle communication devices, they do not have a short radio network temporary identifier RNTI and a dedicated downlink DL control channel for HARQ feedback or a communication device specific search space. From the perspective of the gNB, in some scenarios, the gNB may not wish to allocate or reserve feedback resources for each communication device. This may be because the gNB may not know how many UEs are participating in the unlicensed transmission. If the gNB were to use common resources to transmit HARQ feedback for all RUs in the same slot for grant-less transmission with diversity, it may be necessary to use the RU index and the communication device identification UE-ID as an index to allow all UEs to detect the correct feedback block for themselves. The signaling overhead in such a scenario may be relatively high. For RRC inactive or RRC connected state UEs, although each of them has a short RNTI and a dedicated DL control channel for HARQ feedback, in some scenarios, for example when the decoding result is negative, it may be a waste of resources to send separate HARQ feedback for all UEs sharing the same RU.

Some embodiments may provide a feedback method, such as a HARQ feedback method. The feedback method may be used for UL grant-free transmission. The feedback method may be used for transmissions with diversity.

Some embodiments may define feedback timing, such as HARQ feedback timing.

Some embodiments may define feedback resources, such as HARQ feedback resources. These feedback resources are feasible for all RRC states. These feedback resources may be intended to minimize communication device power consumption. These feedback resources may be intended to minimize resource consumption and/or signaling overhead at the gNB.

Some embodiments may provide a HARQ feedback method for UL grant-less transmission with diversity. In the following, it is assumed that the communication device will send P copies of a packet, where P is an integer ≧ 2.

In some embodiments, two levels of HARQ feedback resources for grant-less transmission with diversity are provided.

In the first level, the gNB configures a separate HARQ feedback resource for each RU within the resource pool, which applies to all communication devices.

In the second level, the gNB configures limited common HARQ feedback resources for the resource pool, which is only applicable for RRC idle UEs. For RRC INACTIVE (RRC _ INACTIVE) and RRC CONNECTED (RRC _ CONNECTED) state UEs, previously proposed UE-specific HARQ feedback resources, such as physical HARQ indicator channel PHICH of LTE or communication device-specific search space in PDCCH of 5G, may be used for second level HARQ feedback resources.

Some embodiments may provide two additional defined HARQ feedback states listed in the table below.

As can be seen from the above table, in some embodiments, the RU-NACK feedback state may not be applicable to the second level HARQ feedback resources.

For HARQ feedback state transmission, if UE-ACK state is transmitted, then in some embodiments a UE-ID is also transmitted.

Some embodiments may define HARQ timing. The timing for the ith copy in the first level HARQ feedback resources may be predefined by the system. For the ith copy sent in RU { Fi, Ti }, the communication device receives first level HARQ feedback resources configured for RU { Fi, Ti } in time slot Ti + k. The parameter k may be defined by an associated standard and/or configured via a SIB (system information block). The value of k may be selected by the base station. The value of k may be configured by the base station.

The timing for the ith copy in the second level HARQ feedback resources may be a receive window [ Ti +1+ k, N + k ] of variable length for the different copies.

The timing for the communication device specific HARQ feedback resources may be the same as the second level HARQ feedback resources.

Some embodiments may provide improved gNB behavior. When the gNB detects the MA signature in the RU { Fi, Ti }, the gNB attempts to decode the data.

If the gNB cannot decode data of any communication device, it sends an RU-NACK for RUs in the slot as defined above in the first level HARQ feedback resources.

If the gNB successfully decodes data for any communication device, the gNB knows the UE-ID and can identify the status of the communication device. Due to the effects of SIC, the gNB can successfully decode a duplicate of data from a particular communication device in a later time slot than the communication device sent the duplicate. Thus, the gNB can recover the ith copy in any slot in time period [ Ti + k, N + k ].

If the communications device transmits a duplicate in RU { Fi, Ti }, then the gNB transmits the UE-ACK along with the UE-ID in the first level HARQ feedback resources for RUs in the slot as defined above.

If the communication device sends a copy earlier than the RU, the gNB can send a UE-ACK based on the communication device status.

For RRC idle communication devices, the gNB may send UE-ACKs with UE-IDs in the latest second level HARQ feedback resources.

For a communication device in RRC inactive or connected state, the gNB may send a UE-ACK in the communication device specific HARQ feedback channel.

Some embodiments may provide improved communication device behavior.

The communication device detects first level HARQ feedback resources for all RUs for which a copy is transmitted. If an RU-NACK is received for a duplicate or nothing is received, the subsequent communication device behavior depends on its state.

For the RRC idle communication device, the communication device detects all second level HARQ feedback resources in the receive window of the replica until the communication device receives a UE-ACK or the window ends.

For an inactive or connected state communication device, the communication device detects a UE-specific HARQ feedback channel in the receive window of the replica until it receives a UE-ACK or the end of the window.

In the case where the communication device receives one or more (total less than P) RU-NACKs for its copies, the communication device waits for the decoding result of the next copy until all copies fail or one of the copies succeeds.

Reference is now made to fig. 6, which is based on the same example of resource pools shown in fig. 5, wherein four communication devices UE1, UE2, UE3 and UE4 transmit their two copies for the same packet in the RU shown in fig. 5. Fig. 5 shows an example where each communication device transmits each packet with two copies.

In this example, it is assumed that each communication device will send a packet twice, which provides two copies of each packet. It should be understood that this is by way of example only, and in other embodiments the number of copies of each packet transmitted may be more than two.

The SIC receiver of the gNB will perform a limited number of iteration steps. In this example, the number of iteration steps may be 2. However, in different embodiments, the number of iterative steps may be different.

To illustrate some embodiments, the communication device states are as follows: UE 1-idle, UE 2-idle, UE 3-idle, and UE 4-connected.

For each RU with frequency-time resources { x, y }, the first level HARQ feedback resources are located in the frequency-time resources { x, y + k }. Fig. 6 illustrates first level and second level HARQ feedback resources for resource units in the resource pool from the unlicensed transmission shown in fig. 5.

For a resource pool with N × M RUs, in an embodiment, the number of second level HARQ feedback resources may be configured by the network as L (1 ≦ L ≦ N). The second level HARQ feedback resources may be evenly distributed in the time domain, as shown in fig. 6. The blocks labeled 50, UE1-ACK, and UE4-ACK may represent second level HARQ feedback resources. The remaining blocks are first level HARQ feedback resources.

The communication device specific HARQ resources may be available for each slot. This is not shown in fig. 6 for simplicity.

It should be understood that fig. 6 is for illustrative purposes. The relative positions of the first and second HARQ feedback resources are merely examples and may be different in different embodiments.

It should be understood that fig. 6 is schematic. The block sizes of the first and second HARQ feedback resources and their relative positions in the figure are only examples. Other embodiments may have different relative positions and/or orientations.

In RU { m +2, n } (see fig. 5), the gNB detects more than one MA signature and knows that a collision occurred. The gbb decodes the data using SIC at the slot level. If it fails, the gNB sends RU-NACKs in the first level HARQ feedback resources for RUs { m +2, n } in slot n + k (see FIG. 6). After both UE1 and UE2 receive RU-NACKs in the first level HARQ feedback resources for RU, since both UE1 and UE2 are in idle state, UE1 and UE2 need to detect all second level HARQ feedback resources in the receive window of their first copies.

In RU { m +3, n +2} (see fig. 5), the gNB also detects more than one MA signature and cannot decode the data. The gNB sends RU-NACK in the first level HARQ feedback resources for RU { m +3, n +2} in slot n +2+ k (see fig. 6). After UE1, UE3, and UE4 receive RU-NACKs in the first level HARQ feedback resources for RUs, UE1 in idle state needs to detect all second level HARQ feedback resources in the receive window of its second copy. The UE3 in idle state needs to detect all second level HARQ feedback resources in the receive window of its first copy. The connected-state UE4 needs to detect the UE-specific HARQ feedback channel in the receive window of its first copy.

In RU { m +4, n +3} (see fig. 5), the gNB detects only one MA signature and successfully decodes the data of UE 2. The gNB transmits the UE-ACK along with the UE-ID of the UE2 in the first level HARQ feedback resources for RU { m +4, n +3} in slot n +3+ k. After the UE2 receives the UE-ACK and its UE-ID in the first level HARQ feedback resource for RU { m +4, n +3}, the UE2 knows that its packets in the resource pool were correctly received.

Since the gNB also knows that there is a copy of UE2 in RU { m +2, n }, it then removes the signal of UE2 in RU { m +2, n } and successfully decodes UE 1. Since UE1 is in the idle state, the gNB will send a UE-ACK with the UE-ID of UE1 in the latest second level HARQ feedback resource of slot n +4+ k, which is referred to as UE1-ACK in fig. 6. After the UE1 receives the UE-ACK and its UE-ID in the second level HARQ feedback resource, the UE1 knows that its packet in the resource pool was correctly received.

The gNB knows that there is another copy of UE1 in the RU { m +3, n +2}, and removes the signal of UE1 in that RU, but cannot decode any other UE.

Because the number of iteration steps for RU { m +3, n +2} does not exceed the threshold, the gNB then waits for decoding results for other copies.

In RU { m +1, n +4} (see fig. 5), the gNB successfully decoded the data of UE 3. It sends a UE-ACK for UE3 in the first level HARQ feedback resources for the RU in slot n +4+ k. After the UE3 receives the UE-ACK and its UE-ID in the first level HARQ feedback resource for RU { m +1, n +4}, it knows that its packets in the resource pool were correctly received.

The gNB also knows that there is a copy of the UE3 in RU { m +3, n +2 }. Then, the gNB removes the UE3 in RU { m +3, n +2} and attempts to decode the remaining signal. If the decoding fails, the gNB will not continue with this RU because the total number of iterative steps exceeds the threshold. If the decoding is successful, the gNB checks the status of the UE 4. Since the UE4 is in the connected state, the gNB sends a UE-ACK for UE4 for RU { m +3, n +2} in the UE-specific HARQ feedback resources in slot n +4+ k, which is referred to as UE4-ACK in fig. 6. After the UE4 receives the UE-ACK in the UE-specific HARQ feedback resources, the UE4 knows that its packets in the resource pool were correctly received.

Using the described feedback method, UE2 and UE4 do not need to send their second copies intended in RU { m, n +5}, as shown in fig. 5.

In some embodiments, the gNB may configure the size of the pool. This may depend on one or more factors such as expected capacity, radio environment parameters, load, and/or others.

Fig. 8 illustrates an example method flow of some embodiments. In this example, there are two transmissions from UE1 and UE2 in the first RU.

In step T1, the base station detects more than one MA signature and knows that a collision has occurred.

In step T2, the base station attempts to decode data using SIC at the slot level.

If it fails, the base station transmits an RU-NACK in the first level feedback resources for the first RU at step T3.

In step T4, the base station receives a packet from the second UE in the second RU.

In step T5, the base station detects only one MA signature and successfully decodes data of UE 2.

In step T6, the base station sends an ACK in the first level feedback resources associated with the second RU with the UE-ID of UE 2.

In step T7, the base station removes the signal of the UE2 from the data received in the first RU.

In step T8, the base station successfully decodes data from UE1 using SIC at the slot level.

In step T9, the base station will send a UE-ACK in the latest second level feedback resource in the second level feedback resource window together with the UE-ID of UE 1. The second level feedback resource window may be used by any UE in an idle state.

Referring to fig. 7, a method flow of an idle state UE is shown.

In step S1, the UE selects RUs for both copies from the resource pool.

In step S2, the UE transmits a first copy in a first RU.

In step S3, the UE detects a first level HARQ feedback channel.

In step S4, the UE determines whether there is a UE-ACK or RU-NACK.

If a UE-ACK is detected, the next step is step S5. In step S5, the UE determines that the transmission of the first packet has succeeded and that the second copy of the packet does not need to be transmitted in the RU. Thus, the packet may be deleted from the packet to be transmitted.

If no RU-NACK has been detected, the next step is step S5. In step S6, the UE detects the second level feedback resource in the reception window of the transmission copy.

In step S7, the UE determines whether feedback is received in the window.

If there is feedback, the next step is step S4. In the case of second level HARQ feedback, the feedback would be UE-ACK.

If there is no feedback, the next step is step S8. In step S8, the UE determines whether the copy that has been transmitted is the first copy.

If the copy is not the first copy, the next step is step S9. In step S9, the UE determines whether the reception window has ended.

If the receive window has not ended, the next step is step S6.

If the receive window has ended, the next step is step S10, where the packet is retransmitted (not one of the two copies, but a new round of diversity transmission for the packet).

If the copy is the first copy in step S8, the next step is step S11. In step S11, the UE determines whether it is time to transmit the second copy in the selected RU.

If it is not time to send the second copy, the next step is step S6.

If it is time to send the second copy, the next step is step S12. In step S12, the UE will send a second copy in the selected second RU.

Step S3 then follows step S12.

For an inactive or connected state UE, step S6 would be modified to detect UE-specific HARQ feedback resources.

Some embodiments may provide a HARQ feedback method for UL grant-less transmission with diversity.

Some embodiments may provide an integrated approach for all UE states.

The HARQ feedback resources and HARQ states of some embodiments may be one or more of efficient signaling overhead and resource consumption.

The HARQ feedback timing of some embodiments may help communication devices with different RRC states receive feedback as quickly as possible. As a result, in some embodiments, if one copy is successfully received, no additional UL resources for the other copies are wasted.

In some embodiments, the method of fig. 9 is provided. The method may be performed by an apparatus. The apparatus may be provided in a user equipment.

In step a1, a plurality of resources are selected from a common pool of resources available to a plurality of communication devices. Different resources will be used to send the corresponding copies of the first packet. In other embodiments, the selection may not be done by the device. In some embodiments, the selection made may be a random or pseudo-random selection.

In step a2, a first copy of the first packet is caused to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource of the plurality of resources.

In step a3, feedback is received from the base station in a first feedback resource, the first feedback resource relating to the first resource. In other embodiments, the first feedback resource may be independent of the first resource.

Of course, one or more of the above steps may be omitted and/or modified. One or more other steps may alternatively or additionally be performed. One or more of the previously described method steps of other embodiments may alternatively or additionally be performed in conjunction with the method of fig. 9.

In some embodiments, the method of fig. 10 is provided. The method may be performed by an apparatus. The apparatus may be provided in a user equipment.

In step B1, information may be caused to be transmitted to a plurality of communication devices. The information indicates a first feedback resource to be monitored and a second feedback resource to be monitored. In some embodiments, this step is optional, and the communication device may determine this information in other ways.

In step B2, a decoding failure is determined for a first resource in the common resource pool. A common resource pool is available to multiple communication devices. The decoding failure is a result of a plurality of packets from the plurality of communication devices being transmitted in the first resource.

In step B3, a negative acknowledgement is caused to be transmitted in a first feedback resource associated with the first resource. The negative acknowledgement is for a first resource of the common resource pool. In other embodiments, the first feedback resource may be independent of the first resource.

Of course, one or more of the above steps may be omitted and/or modified. One or more other steps may alternatively or additionally be performed. One or more of the previously described method steps of other embodiments may alternatively or additionally be performed in conjunction with the method of fig. 10.

In general, the various examples shown may be implemented in hardware or in dedicated circuitry, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the embodiments are not limited thereto.

While various aspects may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

Some embodiments may be implemented by computer software executable by a data processor, such as in a processor entity, or by hardware, or by a combination of software and hardware. The data processor may be provided by the apparatus. The apparatus may be provided in a communication device or a base station. Computer software or programs (also referred to as program products) including software routines, applets and/or macros can be stored in any device-readable data storage medium and they include program instructions to perform particular tasks. The computer program may be provided by a non-transitory computer program product. The computer program product may comprise one or more computer-executable components configured to perform the methods described in the present disclosure when the program is run. The one or more computer-executable components may be at least one software code or portion thereof.

Further in this regard it should be noted that any block of the logic flow as in the figures may represent a program step, or an interconnected set of logic circuits, blocks and functions, or a combination of a program step and a logic circuit, block and function. The software may be stored on physical media such as memory chips or memory blocks implemented within the processor, magnetic media such as hard or floppy disks, and optical media such as DVDs and data variants thereof, CDs. The physical medium is a non-transitory medium.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processor may be of any type suitable to the local technical environment, and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), FPGAs, gate level circuits, and processors based on a multi-core processor architecture, as non-limiting examples.

Examples of the disclosed embodiments may be implemented in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The examples described herein are to be understood as illustrative examples of embodiments. Other embodiments and examples are contemplated. Any feature described in relation to any one example or embodiment may be used alone or in combination with other features. Furthermore, any feature described in relation to any one example or embodiment may also be used in combination with one or more features of any other example or embodiment, or any combination of any other example or embodiment. Furthermore, equivalents and modifications not described herein may also be employed within the scope of the invention as defined in the claims.

Claims

1. A method, comprising:

selecting a plurality of resources from a common pool of resources available to a plurality of communication devices, different ones of the resources being used to transmit respective copies of the first packet;

causing a first copy of the first packet to be transmitted from the first communication device to the base station, the first copy of the first packet being transmitted on a first resource of the plurality of resources; and

feedback is received from the base station in a first feedback resource, the first feedback resource being related to the first resource.

2. The method of claim 1, comprising: in response to not receiving an acknowledgement in the first feedback resource for the first communication device, monitoring a second feedback resource for acknowledgement information associated with the first copy of the packet.

3. The method of claim 2, wherein the second feedback resource is provided within a window.

4. A method according to any preceding claim, comprising: in response to not receiving an acknowledgement in the first feedback resource for the first communication device, causing a second copy of the first packet to be transmitted using a second resource of the plurality of resources.

5. The method of claim 4, when appended to claim 2 or 3, wherein the second copy of the first packet is transmitted only if an acknowledgement for the first communication device is not received in the second feedback resource and the first feedback resource.

6. The method of any preceding claim, wherein the feedback in the first feedback resource comprises negative acknowledgements for a plurality of communication devices selecting the first resource in a common resource pool.

7. The method of any preceding claim, wherein the feedback in the first feedback resource comprises an acknowledgement to a different communication device of the plurality of communication devices.

8. A method according to any preceding claim, wherein further copies of the first packet are caused to be transmitted when the respective copies of the first packet have been sent.

9. A method according to any preceding claim, wherein the feedback in the first feedback resource is an acknowledgement to the first communications device and in response thereto, the further copy of the first packet is caused to be not transmitted.

10. A method according to any preceding claim, comprising receiving information from the base station, the information indicating respective first feedback resources to be monitored and respective second feedback resources to be monitored.

11. A method, comprising:

causing information to be transmitted to a plurality of communication devices, the information indicating a first feedback resource to be monitored and a second feedback resource to be monitored;

determining a decoding failure for a first resource in a common resource pool, the common resource pool being available to a plurality of communication devices, the decoding failure being a result of a plurality of packets from the plurality of communication devices being transmitted in the first resource; and

causing a negative acknowledgement to be transmitted in a first feedback resource related to the first resource, the negative acknowledgement being for the first resource in the common resource pool.

12. The method of claim 11, comprising: the method further includes successfully decoding a second copy of the first packet, the second copy of the first packet received from a first communication device of the plurality of communication devices in a second resource of the common resource pool, and removing the first copy of the first packet from the plurality of packets, the plurality of packets received from the plurality of communication devices in the first resource.

13. The method of claim 12, comprising: determining whether a second packet of the plurality of packets received from a second communication device of the plurality of communication devices in the first resource after removing the first packet is decodable, and if so, decoding the second packet and causing acknowledgement information to be transmitted on the second feedback resource.

14. A method according to claim 12 or 13, wherein the second feedback resource is defined relative to the first resource and later than the first feedback resource.

15. A method according to any of claims 11 to 14, comprising configuring the size of the common resource pool.

16. A method according to any preceding claim, wherein at least one of the communication devices is in an idle state.

17. A computer program comprising computer executable code which, when run on at least one processor, is configured to perform the method according to any of the preceding claims.

18. An apparatus comprising means for:

19. An apparatus comprising means for: