CN109361499B

CN109361499B - Method, wireless communication device, and computer readable medium for reporting ACK/NACK with dynamic TDD configuration

Info

Publication number: CN109361499B
Application number: CN201811462125.0A
Authority: CN
Inventors: 郭志恒; 范锐; 宋兴华; 埃里克·埃里克松
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2013-01-25
Filing date: 2014-01-17
Publication date: 2022-02-08
Anticipated expiration: 2034-01-17
Also published as: CN104956618B; CN109361499A; CN104956618A

Abstract

The present disclosure relates to a method for reporting ACK or NACK in dynamic TDD configuration in a wireless communication device. In the method, an indication of a reference UL TDD configuration and a reference DL TDD configuration is indicated. Then, ACK/NACK bits having a fixed number of ACK/NACK bits based on the reference DL TDD configuration are reported at the timing based on the reference DL TDD configuration. The disclosure also relates to a wireless communication device reporting ACK/NACK in dynamic TDD configuration.

Description

Method, wireless communication device, and computer readable medium for reporting ACK/NACK with dynamic TDD configuration

The present application is a divisional application entitled "method, wireless communication device, and computer readable product for reporting ACK/NACK in dynamic TDD configuration at a wireless communication device" of chinese patent application No.201480006152.0 filed on 17/1/2014.

Technical Field

The technology presented in this disclosure relates generally to wireless communication networks, and in particular, to wireless communication networks using Time Division Duplexing (TDD) (e.g., Long Term Evolution (LTE) TDD) (without limitation). More particularly, the present disclosure relates to methods, wireless communication devices (e.g., User Equipment (UE), and computer readable products for reporting positive Acknowledgements (ACK)/Negative Acknowledgements (NACK) in a dynamic TDD configuration in a wireless communication device (e.g., UE).

Background

This section is intended to provide a background for various embodiments of the technology described in this disclosure. This portion of the description may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Thus, unless otherwise indicated herein, what is described in this section is not prior art to the description and/or claims in this disclosure, and is not admitted to be prior art by inclusion in this section alone.

In a typical cellular radio system, a wireless communication device (e.g., User Equipment (UE)) may communicate with one or more Core Networks (CNs) via a Radio Access Network (RAN). The RAN generally covers a geographical area which may be divided into radio cell areas. Each radio cell area may be served by a base station (e.g., nodeb (umts) or enodeb (lte)). A radio cell is a geographical area where radio coverage is typically provided by a radio base station at a base station site. Each radio cell may be identified by an identity within the local radio cell, which is broadcast within the radio cell. The base station communicates over an air interface operating on radio frequencies with wireless communication devices within range of the base station. In some radio access networks, multiple base stations may be connected to a Radio Network Controller (RNC) or a Base Station Controller (BSC). The radio network controller may be configured to monitor and coordinate various activities of the plurality of base stations connected thereto. The radio network controller may also be connected to one or more core networks.

The Universal Mobile Telecommunications System (UMTS) is a third generation mobile communication system that has evolved from the global system for mobile communications (GSM). Universal Terrestrial Radio Access Network (UTRAN) is essentially a radio access network using Wideband Code Division Multiple Access (WCDMA) for wireless communication devices. As an alternative to WCDMA, time division synchronous code division multiple Access (TD-SCDMA) may be used. In a standardization forum known as the third generation partnership project (3GPP), telecommunication providers specifically propose and approve standards for third generation networks and UTRAN and study, for example, enhanced data rates and radio capacity. The 3GPP is starting to evolve UTRAN and GSM based radio access network technologies. A first version of the evolved universal terrestrial radio access network (E-UTRAN) specification has been released. Evolved universal terrestrial radio access network (E-UTRAN) includes Long Term Evolution (LTE) and System Architecture Evolution (SAE). Long Term Evolution (LTE) is a variant of 3GPP radio access networks where the radio base station is connected to the core network (e.g. via an Access Gateway (AGW)), not to the Radio Network Controller (RNC) node. Generally, in LTE, the functionality of a Radio Network Controller (RNC) node is distributed between a radio base station node (eNodeB in LTE) and an AGW. Thus, the Radio Access Network (RAN) of an LTE system has a structure sometimes referred to as a "flat" structure that includes radio base station nodes that do not report to a Radio Network Controller (RNC) node.

Transmissions and receptions of a node (e.g., a wireless terminal, such as a UE) in a cell system (e.g., LTE) can be multiplexed in the frequency or time domain (or a combination thereof). In Frequency Division Duplex (FDD), Downlink (DL) and Uplink (UL) transmissions are made in different and sufficiently separated frequency bands. In Time Division Duplex (TDD), DL and UL transmissions are made in different and non-overlapping time slots. Thus, TDD can operate in unpaired spectrum, while FDD generally requires paired spectrum.

Typically, transmission signals in a wireless communication system are organized in some form of frame structure or frame configuration. For example, LTE typically uses 10 subframes 0-9 of the same size, 1ms in length, per radio frame, as shown in fig. 1. In the TDD case shown in fig. 1, there is typically only a single carrier frequency, and the UL and DL are separated in time. Because the uplink and downlink transmissions use the same carrier frequency, both the base station and the UE need to switch from transmitting to receiving, or vice versa. An important aspect of TDD systems is to provide a large enough guard time in the absence of DL or UL transmissions to code for interference between UL and DL transmissions. For LTE, a special subframe (e.g., subframe #1, and in some cases, subframe # 6) provides this guard time. TDD special subframes are generally divided into three parts: downlink part (DwPTS), Guard Period (GP), and uplink part (UpPTS). The remaining subframes are allocated to UL or DL transmission. Table 1 below shows example UL and DL configurations (also referred to as "TDD configurations" in this disclosure). Further, table 2 shows an exemplary special subframe configuration.

Table 1 example UL and DL configurations in TDD

Table 2 example configuration of special subframes

With different DL/UL configurations, TDD allows for different asymmetries in the amount of resources allocated for UL and DL transmissions, respectively. In LTE, there are seven different configurations, see fig. 2. In general, to avoid significant interference between DL and UL transmissions between different radio cells, neighboring radio cells should have the same DL/UL configuration. Otherwise, UL transmissions in one radio cell may interfere with DL transmissions in a neighboring radio cell (and vice versa). Therefore, the DL/UL asymmetry does not generally vary between radio cells. The DL/UL asymmetry configuration may be signaled (i.e., communicated) as part of the system information and remain fixed for long periods of time.

Thus, TDD networks typically use a fixed frame configuration with some subframes being UL and some subframes being DL. This may prevent, or at least limit, the application of UL and/or DL resource asymmetry to flexibility in varying wireless data scenarios.

In future networks, it is anticipated that we will see more and more localized services, where most users will be in hot spots, indoor areas, or residential areas. These users will be located in the cluster and will generate different UL and DL traffic at different times. This essentially means that in future local area cells the dynamic characteristics of UL and UL resources will need to be adjusted for instantaneous (or near instantaneous) traffic changes.

TDD has the possible feature that the available frequency bands can be configured in either UL or DL in different time slots. This allows for asymmetric UL/DL allocations, which are a characteristic property of TDD, but not possible in FDD. There are seven different UL/DL allocations in LTE that provide 40% -90% of the DL resources.

In current networks, the UL/DL configuration is semi-statically configured and therefore may not match the instantaneous traffic situation. This will result in inefficient resource utilization in the UL and DL, especially in cells with a small number of users. To provide more flexible TDD configurations, so-called dynamic TDD (sometimes also referred to as flexible TDD) has been introduced. Thus, dynamic TDD configures the TDD UL/DL asymmetrically with the current traffic situation to optimize the user experience. Dynamic TDD provides the ability to configure subframes as "flexible" subframes. Thus, some subframes may be dynamically configured for either UL or DL transmission. The subframes may be configured for UL transmission or DL transmission, e.g. depending on radio traffic situation in the cell. Thus, dynamic TDD may be desirable to achieve possible performance improvements in TDD systems when there is a potential load imbalance between UL and DL. In addition, dynamic TDD methods may also be used to reduce network energy consumption. It is expected that dynamic UL/DL allocation (and thus indicated in this section "dynamic TDD") should provide a good match of allocated resources to instantaneous traffic.

UL scheduling may be indicated with Downlink Control Information (DCI) format 0 or Physical hybrid automatic repeat request (HARQ) indicator channel (PHICH) in DL subframes (see section 8 in 3GPP technical standard 3GPP TS 36.213, "Evolved Universal Radio Access (E-UTRA); Physical layer procedures", v.11.1.0).

Disclosure of Invention

Various embodiments of the present technology have been made based on the above considerations and the like.

According to an aspect of the present disclosure, a method in a wireless communication device for reporting ACK or NACK in dynamic TDD configuration is provided. In the method, an indication of a reference ul TDD configuration and a reference DL TDD configuration is indicated. Then, ACK/NACK bits having a fixed number of ACK/NACK bits based on the reference DL TDD configuration are reported at the timing based on the reference DL TDD configuration.

According to another aspect of the present disclosure, a wireless communication device for reporting ACK/NACK in dynamic TDD configuration is provided, the wireless communication device comprising a receiver, a transmitter, a memory, and a processor. The memory is configured to store a TDD configuration. The processor is configured to control the receiver to receive an indication of a reference ul tdd configuration and a reference dl tdd configuration. The processor is further configured to: the control transmitter reports ACK/NACK bits having a fixed number of ACK/NACK bits based on the reference DL TDD configuration at a timing based on the reference DL TDD configuration.

According to another aspect of the present disclosure, there is provided a terminal for reporting ACK or NACK in dynamic TDD configuration. The terminal includes: means for receiving an indication of a reference ul tdd configuration and a reference dl tdd configuration; and means for reporting the ACK/NACK bits with a fixed number of ACK/NACK bits based on the reference DL TDD configuration at a timing based on the reference DL TDD configuration.

According to another aspect of the present disclosure, there is provided a wireless communication device for reporting ACK or NACK in dynamic TDD configuration, the wireless communication device comprising a memory and a processor, the memory containing instructions executable by the processor, wherein the user terminal is operable to: an indication of a reference ul tdd configuration and a reference dl tdd configuration is received. The control transmitter reports ACK/NACK bits having a fixed number of ACK/NACK bits based on the reference DL TDD configuration at a timing based on the reference DL TDD configuration.

With the technical solution disclosed in the present disclosure, a simple dynamic TDD solution can be implemented, and also L1 controlled dynamic TDD can be implemented. The wireless communication terminal will not be aware of how many ACK/NACK bits will be reported. In particular, this solution is very useful for those dynamic TDD solutions that employ

TDD configurations

0, 1, 2, 6.

Drawings

The above and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.

Fig. 1 shows the time/frequency structure of the uplink/uplink of LTE TDD;

fig. 2 is a diagram illustrating an example of seven different downlink/uplink configurations for LTE TDD;

fig. 3 is a flow chart illustrating a process of the method of the present disclosure.

Fig. 4 is a diagram illustrating ACK/NACK separation coding and mapping.

Fig. 5 is a schematic block diagram of a UE in accordance with some embodiments of the present disclosure.

Fig. 6 is a schematic block diagram of a UE in accordance with some embodiments of the present disclosure.

Fig. 7 is a schematic block diagram of a structure according to some embodiments of the present disclosure.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular architecture, interfaces, techniques, etc., for example. However, it will be apparent to one skilled in the art that the techniques described herein may be practiced in other embodiments that depart from these specific details. That is, those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the technology and are included within its scope. In some instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description with unnecessary detail. All statements herein reciting principles, aspects, and embodiments, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Further, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., elements developed that perform the same function, regardless of structure). Thus, for example, it will be appreciated by those skilled in the art that the block diagrams herein can represent conceptual views of illustrative circuitry embodying the principles of the technology. It will be appreciated that any flow charts and the like represent various processes which may be substantially represented in computer readable media and so executed by a computer or processor, even though not explicitly shown. The functions of the various elements including functional blocks labeled or described as "processors" may be provided through the use of dedicated hardware as well as hardware capable of executing software in the form of coded instructions stored on a computer readable medium. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared or distributed. These functions are understood to be computer-implemented, i.e. machine-implemented. Moreover, use of the term "processor" should also be construed to refer to other hardware capable of performing these functions and/or executing software, and may include, without limitation, Digital Signal Processor (DSP) hardware, reduced instruction set processors, hardware (e.g., digital or analog) circuitry, and a state machine capable of performing these functions, as appropriate.

As used hereinafter, the term "UE" may refer to a mobile terminal, a User Terminal (UT), a wireless terminal, a wireless communication device, a wireless transmit/receive unit (WTRU), a mobile phone, a cell phone, and the like. Furthermore, the term UE includes MTC (machine type communication) devices, which do not necessarily include human interaction. Furthermore, the term "radio network node" as used herein generally denotes a fixed point capable of communicating with a UE. Thus, it may be referred to as a base station, radio base station, nodeB or evolved nodeB (enb), relay node, etc.

In L1 controlled dynamic TDD (see R1-130558 "signaling supported for dynamic TDD", Ericsson, ST-Ericsson), the UE will adjust its scheduling timing for UL and DL based on the two TDD configurations, respectively. The UE will schedule UL transmissions based on the reference UL TDD configuration and DL transmissions based on the reference DL TDD configuration. One example is to schedule UL transmissions using TDD configuration 0 and DL transmissions using TDD configuration 1. In this case, subframes #4 and #9 are used as flexible subframes, which may be used for UL or DL.

Benefits of using L1 controlled dynamic TDD are: it provides full dynamic control giving the greatest performance advantage. It is also ensured that the control signaling (except for DL scheduling) will not experience cross-link interference. It has a natural way of handling HARQ continuity between switches. It also has minimal signaling overhead since the direction is implicitly controlled by the scheduling that each transmission anyway requires.

However, the inventors herein have observed the following problems.

For TDD configuration 0 and other configurations 1-6, although the payload size of DCI format 0 is the same, there are two bits with different interpretations in the payload (these two bits are just after the cyclically shifted bit for DM RS).

In TDD configuration 0, these two bits are used for UL index. Differently, in TDD configurations 1-6, these two bits are used for DAI (downlink assignment index). Different interpretations of these two bits will result in different UE behavior.

If TDD configuration 0 is used as UL reference TDD configuration, all possible UL subframes can be scheduled, but this is done with the help of UL index in DCI format 0. However, as described above, the two bits for UL index in DCI format 0 in TDD configuration 0 will be interpreted as DAI in the other TDD configurations 1-6. The DAI is used to indicate the number of bits of ACK/NACK used by the UE to report feedback of the relevant downlink subframe. Therefore, if TDD configuration 0 is used as the reference TDD configuration, there is ambiguity in the number of ACK/NACK bits.

In this regard, the following problems arise:

in dynamic TDD, assuming that N TDD configurations (2 ≦ N ≦ 7) are included in the dynamically changing UL-DL configuration set (including UL-DL configuration 0), the UL subframe scheduling mechanism follows the mechanism of UL-DL configuration 0, and all possible UL subframes can be scheduled through DCI format 0.

Since the UL index is included in the UL scheduling of subframes #3 and #8, the UL index in UL-DL configuration 0 and two bits in DCI format 0 of DAI in other UL-DL configurations are always interpreted as UL indices to dynamically schedule UL subframes.

However, the DAI of DCI format 0 in TDD configuration 1, for example, indicates the number of ACK/NACK bits that the UE should feed back to the eNB on the PUSCH. If the number of ACK/NACK bits does not match between the eNB and the UE, the ACK/NACK bits will not be decoded correctly. This will lead to uplink radio link failure as the UL HARQ mechanism is destroyed.

On the other hand, the N TDD configurations do not include TDD configuration 0. Then, a dynamic change between any two UL-DL configurations other than TDD configuration 0 will not result in a conflict of understanding of DCI format 0.

In UL-DL configuration 0, 60% of resources are allocated to UL, and TDD configuration 0 is a configuration in which the number of unique UL subframes is greater than the number of DL subframes. Therefore, TDD configuration 0 is applicable to scenarios with heavy UL traffic. Therefore, UL-DL configuration 0 should be included in dynamic TDD. Furthermore, if DCI format 0 is not detected, the UE will not know on which subframe to report the ACK/NACK bit.

According to the proposed technical solution, a method for reporting ACK/NACK with dynamic TDD configuration by UE is proposed. In the method, referring to fig. 3, which shows a flowchart of a method 300, an indication of a reference UL TDD configuration and a reference DL TDD configuration is received (e.g., via a physical downlink control channel, PDCCH) (step 310). Thereafter, ACK/NACK bits having a fixed number of ACK/NACK bits based on the reference DL TDD configuration are reported at a timing based on the reference DL TDD configuration. (step 340).

Method 300 may also include two additional steps, step 320 and step 330 (shown as dashed boxes in fig. 3) between step 310 and step 340. In step 320, DCI (e.g., DCI format 0) for UL scheduling is received (e.g., via PDCCH) based on the reference DL TDD configuration. Then, in step 330, DCI for UL scheduling is interpreted based on the reference UL TDD configuration (e.g., UL index bit if the reference UL TDD configuration is TDD configuration 0, or DAI bit if the reference TDD configuration is one of TDD configurations 1-6).

In the present disclosure, the fixed number of ACK/NACK bits may be determined based on (e.g., fixed to) a maximum number of bits available for one or more DL subframes allocated to the UE in a reference DL TDD configuration.

In the present disclosure, the reference UL TDD configuration may be TDD configuration 0, and the reference DL TDD configuration may be one of TDD configurations 1-6.

Returning to fig. 2, TDD configuration 0 has a UL/DL traffic ratio of 60%, TDD configuration 1 has a UL/DL traffic ratio of 40%, TDD configuration 2 has a UL/DL traffic ratio of 20%, TDD configuration 3 has a UL/DL traffic ratio of 30%, TDD configuration 4 has a UL/DL traffic ratio of 20%, TDD configuration 5 has a UL/DL traffic ratio of 10%, and TDD configuration 6 has a UL/DL traffic ratio of 50%.

Hereinafter, some examples will be explained in detail by assuming that the reference UL TDD configuration is TDD configuration 0, and the reference DL TDD configuration is TDD configuration 1 or TDD configuration 2. In these examples, subframes #3, #4, #8, and #9 are flexible subframes that may be allocated as UL and DL subframes.

Example 1-TDD configuration 0(UL), TDD configuration 1(DL)

When the UE receives DCI format 0, the UE interprets the received DCI format 0 based on TDD configuration 0, i.e., two bits in DCI format 0 for UL index in TDD configuration 0 and for DAI in TDD configuration 1 are interpreted as UL index bits.

The UE reports ACK/NACK bits through the following mechanism of UL-DL configuration 1 (i.e., by determining the timing and number of ACK/NACK based on TDD configuration 1).

If one or both of subframes #2 and #7 are allocated to the UE through DCI format 0, the reported ACK/NACK bits include 2 bits in

subframe #

2 and 2 bits in subframe #7 (see section 10.1.3.1 in 3GPP technical Specification 3GPP TS 36.213, "Evolved Universal Radio Access (E-UTRA); Physical layer procedure," v.11.1.0). That is, the number of ACK/NACK bits is fixed to the maximum number of bits available in TDD configuration 1 of one or more subframes allocated to the UE.

If one or both of subframes #3 and #8 are allocated to the UE through DCI format 0, the reported ACK/NACK bits include 1 bit in

subframe #

3 and 1 bit in subframe #8 (see section 10.1.3.1 in 3GPP technical Specification 3GPP TS 36.213, "Evolved Universal Radio Access (E-UTRA); Physical layer procedures," v.11.1.0). That is, the number of ACK/NACK bits is fixed to the maximum number of bits available in TDD configuration 1 of one or more subframes allocated to the UE.

Example 2-TDD configuration 0(UL), TDD configuration 2(DL)

When the UE receives DCI format 0, the UE interprets the received DCI format 0 based on TDD configuration 0, i.e., two bits in DCI format 0 for UL index in TDD configuration 0 and for DAI in TDD configuration 2 are interpreted as UL index bits.

The UE reports the ACK/NACK bits through the following mechanism of UL-DL configuration 2, i.e., by determining the reporting timing and number of ACK/NACK based on the DAI of DCI format 0 of the subframe received according to TDD configuration 2.

If one or both of subframes #2 and #7 are allocated to the UE through DCI format 0, the reported ACK/NACK bits include 4 bits in

subframe #

2 and 4 bits in subframe #7 (see section 10.1.3.1 in 3GPP technical Specification 3GPP TS 36.213, "Evolved Universal Radio Access (E-UTRA); Physical layer procedures," v.11.1.0). That is, the ACK/NACK bit number is fixed to the maximum bit number available in TDD configuration 2 of one or more subframes allocated to the UE.

In some embodiments (including but not limited to examples 1 and 2 above), each ACK/NACK bit corresponds to a DL subframe mapped to the current Physical Uplink Shared Channel (PUSCH). The UE sets an ACK/NACK bit corresponding to the DL subframe to NACK if a Physical Downlink Control Channel (PDCCH) for DL scheduling is not detected in the DL subframe. The eNB will decide which ACK/NACK bits reported by the UE are valid according to the DL scheduling information.

For example, in example 2 above, the ACK/NACK reporting mechanism would follow that of UL-DL configuration 2. For example, if subframe #2 is allocated to the UE, the UE will report 4-bit ACK/NACK to the eNB in subframe #2, where the 4-bit ACK/NACK corresponds to subframes #4, #5, #8, and #6 of the last DL frame (see section 10.1.3.1 in 3GPP technical Specification 3GPP TS 36.213, "Evolved Universal Radio Access (E-UTRA); Physical layer procedure," v.11.1.0). The eNB will decide which ACK/NACK bit is valid. For example, if subframe #5 of the last DL frame is not allocated to the UE, the eNB will determine that the ACK/NACK bit corresponding to subframe #5 is invalid.

Here, a trigger mechanism may be introduced using DCI for DL scheduling. The UE does not report ACK/NACK bits if DCI for DL scheduling is not received/detected in any DL subframe. If DCI for DL scheduling is received/detected in a DL subframe, a UL subframe mapped to the DL subframe may be determined and a maximum number of ACK/NACK bits available for the DL subframe mapped to the UL subframe in a reference DL TDD configuration will be reported. For those subframes where no DL transmission or DCI is received, the corresponding ACK/NACK bit will be set to NACK.

As an extension, the UE may only be filled with NACKs for subframes following the received/detected DCI information containing the correct DAI (i.e., the DAI corresponding to the DAI expected by the UE).

In some embodiments, as shown in fig. 4, when the UE is configured for dynamic TDD, the UE may change its encoding process of ACK/NACK bits. For example, the UE may separately encode the ACK/NACK bits and map them to separate resource elements in the UL transmission. The resource mapping may depend on the value of the associated DAI (if any) or the subframe index from which the ACK/NACK is generated.

Fig. 5 is a schematic block diagram of a UE 500 in accordance with some embodiments of the present disclosure.

As shown, UE 500 includes a receiver 510, a transmitter 520, a memory 530, and a processor 540. Memory 530 stores TDD configurations (e.g., TDD configurations 0-6). Processor 540 controls receiver 510 to receive instructions for a reference UL TDD configuration and a reference DL TDD configuration (e.g., according to instructions stored in memory 530). Processor 540 also controls transmitter 520 (e.g., according to instructions stored in memory 530) to report ACK/NACK bits having a fixed number of ACK/NACK bits based on the reference DL TDD configuration at a timing based on the reference DL TDD configuration. Processor 540 also controls (e.g., according to instructions stored in memory 530) receiver 510 to receive DCI for UL scheduling based on the reference DL TDD configuration. Processor 540 then interprets the received DCI for UL scheduling based on the reference UL TDD configuration (e.g., according to instructions stored in memory 530).

As described above, the fixed number of ACK/NACK bits may be determined based on (e.g., fixed to) a maximum number of bits available in a reference DL TDD configuration for one or more DL subframes allocated to the UE 500. As described above, the reference UL TDD configuration may be TDD configuration 0, and the reference DL TDD configuration may be one of TDD configurations 1-6.

Similarly, the UE 500 may be applied in example 1 or 2 above, where the reference UL TDD configuration is TDD configuration 0, and the reference DL TDD configuration is TDD configuration 1 or TDD configuration 2.

In some embodiments (including but not limited to examples 1 and 2 above), each ACK/NACK bit corresponds to a DL subframe mapped to the current Physical Uplink Shared Channel (PUSCH). The processor 540 may set an ACK/NACK bit corresponding to the DL subframe to NACK if the receiver 510 does not receive a PDCCH for DL scheduling in the DL subframe.

According to the triggering mechanism described above, if the receiver 510 does not receive DCI for DL scheduling in any DL subframe, the processor 540 controls the transmitter 520 not to report ACK/NACK bits.

Further, in the embodiment shown in fig. 4, processor 540 may separately encode the ACK/NACK bits and map them to separate resource elements in the UL transmission.

Fig. 6 is a schematic block diagram of a UE 600 in accordance with some embodiments of the present disclosure.

The part of the UE 600 that is most affected by the adaptation for the method described herein is shown as a setup 601 surrounded by a dashed line. The UE 600 may be configured to operate in, for example, LTE and/or WCDMA systems. The UE 600 and the settings 601 are also configured to communicate with other entities via a communication unit 602 which may be considered as part of the settings 601. The communication unit 602 comprises means for wireless communication, such as one or more receivers, transmitters and/or transceivers. The arrangement 601 or UE 600 may also comprise other functional units 607, e.g. functional units providing conventional UE functionality, and may also comprise one or more memory units 606.

The arrangement 601 may be implemented, for example, by one or more of a processor or microprocessor and available software, as well as memory for storing the software, a Programmable Logic Device (PLD) or other electronic component or processing circuitry configured to perform the actions described above, and as shown in fig. 3.

The arrangement 601 of the UE 600 may be implemented and/or described as follows.

The arrangement 601 or the UE 600 comprises a receiving unit 610, which receiving unit 610 may be adapted or configured to receive an indication of a reference UL TDD configuration and a reference DL TDD configuration. The arrangement 601 or the UE 600 further comprises a transmitting unit 620, the transmitting unit 620 being adapted or configured to report ACK/NACK bits with a fixed number of ACK/NACK bits based on the reference DL TDD configuration at a timing based on the reference DL TDD configuration. The receiving unit 610 may also be adapted or configured to receive DCI for UL scheduling based on the reference DL TDD configuration. The arrangement 601 or the UE 600 may further comprise an interpreting unit 630, the interpreting unit 630 being adapted or configured to interpret the received DCI for UL scheduling based on the reference DL TDD configuration. The receiving unit 610, the transmitting unit 620 and the interpreting unit 630 perform their respective operations, e.g. according to instructions stored in the one or more memory units 606.

As described above, the fixed number of ACK/NACK bits may be determined based on (e.g., fixed to) the maximum number of bits available for one or more DL subframes allocated to the UE 600 in the reference DL TDD configuration.

As described above, the reference UL TDD configuration may be TDD configuration 0, and the reference DL TDD configuration may be one of TDD configurations 1-6.

Similarly, the UE 600 may be applied in the above example 1 or 2, in example 1 or 2 the reference UL TDD configuration is TDD configuration 0, and the reference DL TDD configuration is TDD configuration 1 or TDD configuration 2.

In some embodiments (including but not limited to examples 1 and 2 above), each ACK/NACK bit corresponds to a DL subframe mapped to the current Physical Uplink Shared Channel (PUSCH). If the receiving unit 610 does not receive a PDCCH for DL scheduling in a DL subframe, the setting 601 sets an ACK/NACK bit corresponding to the DL subframe to NACK.

According to the above triggering mechanism, if the receiving unit 610 does not receive DL scheduled DCI in any DL subframe, the transmitting unit 620 will not report ACK/NACK bits.

Further, in the embodiment shown in fig. 4, the settings 601 may encode the ACK/NACK bits separately and map them to separate resource elements in the UL transmission.

Fig. 7 schematically shows an embodiment of an arrangement 700 that may be used in a UE 600. A processing unit 606 is included in the arrangement 700, for example with a Digital Signal Processor (DSP). Processing unit 606 can be a single unit or multiple units that perform different actions of the processes described herein. The arrangement 700 may further comprise an input unit 602 for receiving signals from other entities, and an output unit 604 for providing signals to other entities. The input unit and the output unit may be arranged as an integrated entity or as shown as an example in fig. 7.

Furthermore, the arrangement 700 comprises a computer program product 708 of at least one non-volatile or volatile memory, such as an electrically erasable programmable read-only memory (EEPROM), a flash memory and a hardware driver. The computer program product 708 comprises a computer program 710, the computer program 710 comprising code/computer readable instructions which, when executed by the processing unit 706 in the arrangement 700, causes the arrangement 700 or a UE comprising the arrangement 700 to perform actions such as the procedure described previously in connection with fig. 3.

The computer program 710 may be configured as computer program code built into the computer program modules 710a-710 d. Thus, in an example embodiment, the code of the computer program 710 in the arrangement 700 comprises a receiving module 710a for receiving an indication of a reference UL TDD configuration and a reference DL TDD configuration. The computer program 710 further includes a transmitting module 710b, the transmitting module 710b reporting ACK/NACK bits having a fixed number of ACK/NACK bits based on the reference DL TDD configuration at a timing based on the reference DL TDD configuration. The receiving module 710a may also be for receiving DCI for UL scheduling based on the reference DL TDD configuration. The computer program 710 may further include an interpretation module 710c for interpreting the received DCI for UL scheduling based on the reference UL TDD configuration. The computer program 710 may also include additional modules, as indicated at module 710d, for controlling and performing other related processes associated with the operation of the UE, for example.

The computer program module may perform the actions of the flowchart shown in fig. 3 as necessary to evaluate the settings 601 in the UE 600. In other words, when different computer program modules are executed in the processing unit 706, the computer program modules may correspond to, for example, the

units

610 and 630 of fig. 6.

Although the code means in the embodiments described above in connection with fig. 7 are implemented as computer program modules which, when executed in a processing unit, cause an apparatus to perform the actions described above in connection with the above figures, at least one code means may be implemented at least partly as hardware circuits in alternative embodiments.

The processor may be a single CPU (central processing unit), and may also include two or more processing units. For example, a processor may include a general purpose microprocessor, an instruction set processor, and/or an associated chipset and/or a special purpose microprocessor (e.g., an Application Specific Integrated Circuit (ASIC)). The processor may also include on-board memory for caching purposes. The computer program product connected to the processor may carry the computer program. The computer program product may comprise a computer readable medium on which the computer program is stored. For example, the computer program product may be a flash memory, a Random Access Memory (RAM), a Read Only Memory (ROM), or an EEPROM; and the above-mentioned computer program modules may in alternative embodiments be distributed over different computer program products in the form of internal memory of the UE.

In an embodiment of the present disclosure, there is provided a wireless communication device (e.g., UE 600) for reporting ACK/NACK in dynamic TDD configuration, the wireless communication device (e.g., UE 600) comprising: the apparatus may include means (e.g., receiving unit 610) for receiving an indication of a reference UL TDD configuration and a reference DL TDD configuration, and means (e.g., transmitting means 620) for reporting ACK/NACK bits having a fixed number of ACK/NACK bits based on the reference DL TDD configuration at a timing based on the reference DL TDD configuration.

The wireless communication device may further include: means (e.g., a receiving unit 610) for receiving Downlink Control Information (DCI) for UL scheduling based on a reference DL TDD configuration; and means (e.g., interpreting unit 630) for interpreting the DCI for UL scheduling based on the reference UL TDD configuration.

The fixed number of ACK/NACK bits may be determined based on a maximum number of bits available for one or more DL subframes allocated to the UE in a reference DL TDD configuration.

In an embodiment of the present disclosure, a terminal (e.g., arrangement 700) for reporting ACKs or NACKs in a dynamic TDD configuration is provided, the terminal (e.g., arrangement 700) comprising a processor (e.g., processing unit 706) and a memory (e.g., computer program product 708), the memory (e.g., computer program product 708) containing instructions executable with the processor (e.g., processing unit 706), wherein the terminal (e.g., arrangement 700) is operable to: receiving an indication of a reference ul TDD configuration and a reference DL TDD configuration; and reporting ACK/NACK bits having a fixed number of ACK/NACK bits based on the reference DL TDD configuration at a timing based on the reference DL TDD configuration.

The memory (e.g., such as the computer program product 708) may further contain instructions executable by the processor, wherein the terminal (e.g., arrangement 700) is operable to: receiving DCI for UL scheduling based on a reference DL TDD configuration; and interpreting DCI for UL scheduling based on the reference UL TDD configuration. The fixed number of ACK/NACK bits may be determined based on a maximum number of bits available in a reference DL TDD configuration for one or more DL subframes allocated to the wireless communication device. In an embodiment of the present disclosure, a computer-readable storage medium (e.g., computer program product 708) is provided that stores instructions that, when executed, cause one or more computer devices to perform a method in accordance with the present disclosure.

Although the present technology is described above with reference to specific embodiments, it is not intended to be limited to the specific form set forth herein. For example, the embodiments presented herein are not limited to existing TDD configurations, but rather, they are equally applicable to new TDD configurations defined in the future. The present technology is limited only by the accompanying claims and, other embodiments than the specific above are equally possible within the scope of these appended claims. The term "comprises/comprising" as used herein does not exclude the presence of other elements or steps. Furthermore, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. Furthermore, singular references do not exclude a plurality. Finally, reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the claims in any way.

Claims

1. A method (300) in a wireless communication device for reporting acknowledgement, ACK, or negative acknowledgement, NACK, in a dynamic time division duplex, TDD, configuration, the method comprising:

receiving (310) an indication of a reference uplink, UL, TDD configuration and a reference downlink, DL, TDD configuration, wherein the reference UL TDD configuration and the reference DL TDD configuration are different; and

at a timing based on the reference DL TDD configuration, reporting (340) ACK/NACK bits with a fixed number of ACK/NACK bits based on the reference DL TDD configuration.

2. The method (300) of claim 1, further comprising:

receiving (320) downlink control information, DCI, for UL scheduling based on a reference DL TDD configuration; and

the DCI for UL scheduling is interpreted (330) based on the reference UL TDD configuration.

3. The method (300) of claim 1 or 2, wherein the fixed number of ACK/NACK bits is determined based on a maximum number of bits available in a reference DL TDD configuration for one or more DL subframes allocated to a wireless communication device.

4. The method (300) of claim 1 or 2, wherein the reference UL TDD configuration is TDD configuration 0 and the reference DL TDD configuration is one of TDD configurations 1-6.

5. The method (300) of claim 4, wherein the reference DL TDD configuration is TDD configuration 1 or TDD configuration 2.

6. The method (300) of claim 1 or 2, according to which each ACK or NACK bit corresponds to a DL subframe mapped to a current UL physical uplink shared channel, PUSCH.

7. The method (300) of claim 2, wherein the DCI for UL scheduling comprises DCI format 0.

8. A wireless communication device (500) for reporting acknowledgement, ACK, or negative acknowledgement, NACK, in a dynamic time division duplex, TDD, configuration, the wireless communication device (500) comprising a receiver (510), a transmitter (520), a memory (530), and a processor (540),

wherein:

the memory (530) is configured to: storing the TDD configuration;

the processor (540) is configured to: control a receiver (510) to receive an indication of a reference uplink, UL, TDD configuration and a reference downlink, DL, TDD configuration, wherein the reference UL TDD configuration and the reference DL TDD configuration are different; and

the processor (540) is configured to: the control transmitter (520) reports ACK/NACK bits having a fixed number of ACK/NACK bits based on the reference DL TDD configuration at a timing based on the reference DL TDD configuration.

9. The wireless communication device (500) of claim 8, wherein:

the processor (540) is further configured to: controlling a receiver (510) to receive downlink control information, DCI, for UL scheduling based on a reference DL TDD configuration; and

the processor (540) is further configured to: the DCI for UL scheduling is interpreted based on a reference UL TDD configuration.

10. The wireless communication device (500) of claim 8 or 9, wherein the fixed number of ACK/NACK bits is determined based on a maximum number of bits available in a reference DL TDD configuration for one or more DL subframes allocated to the wireless communication device.

11. The wireless communication device (500) according to claim 8 or 9, wherein the reference UL TDD configuration is TDD configuration 0 and the reference DL TDD configuration is one of TDD configurations 1-6.

12. The wireless communication device (500) of claim 11, wherein the reference DL TDD configuration is TDD configuration 1 or TDD configuration 2.

13. The wireless communication device (500) according to claim 8 or 9, wherein each ACK or NACK bit corresponds to a DL subframe mapped to a current UL physical uplink shared channel, PUSCH.

14. The wireless communication device (500) of claim 8 or 9, wherein the processor (540) sets an ACK or NACK bit corresponding to a DL subframe to NACK if the receiver (510) does not receive a physical downlink control channel, PDCCH, for DL scheduling in the DL subframe.

15. A computer-readable storage medium (708) storing instructions that, when executed, cause one or more computing devices to perform the method of any of claims 1-7.