WO2015018040A1

WO2015018040A1 - DOWNLINK ASSIGNMENT INDEX (DAI) AND TIMING DESIGN FOR TIME DIVISION DUPLEXING (TDD) ENHANCEMENT FOR INTERFERENCE MANAGEMENT AND TRAFFIC ADAPTATION (eIMTA)

Info

Publication number: WO2015018040A1
Application number: PCT/CN2013/081104
Authority: WO
Inventors: Haipeng Lei
Original assignee: Nokia Corporation; Nokia (China) Investment Co., Ltd.
Priority date: 2013-08-08
Filing date: 2013-08-08
Publication date: 2015-02-12

Abstract

Systems, methods, apparatuses, and computer program products for an uplink (UL) downlink assignment index (DAI) design and corresponding timing for TDD enhanced interference management and traffic adaptation (eIMTA). One method includes re-using two-bit transmit power control (TPC) in UL grant as UL DAI to indicate the total number of subframes with PDSCH transmissions and with PDCCH indicating downlink SPS release to the UE in a corresponding downlink subframe set.

Description

DOWNLINK ASSIGNMENT INDEX (DAI) AND TIMING DESIGN FOR TIME DIVISION DUPLEXING (TDD) ENHANCEMENT FOR

INTERFERENCE MANAGEMENT AND TRAFFIC ADAPTATION

(elMTA)

BACKGROUND:

Field:

[0001] Embodiments of the invention generally relate to mobile communications networks, such as, but not limited to, the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), Long Term Evolution (LTE) Evolved UTRAN (E-UTRAN), and/or LTE- A.

Description of the Related Art:

[0002] Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) refers to a communications network including base stations, or Node Bs, and for example radio network controllers (RNC). UTRAN allows for connectivity between the user equipment (UE) and the core network. The RNC provides control functionalities for one or more Node Bs. The RNC and its corresponding Node Bs are called the Radio Network Subsystem (RNS). In case of E-UTRAN (enhanced UTRAN), no RNC exists and most of the RNC functionalities are contained in the enhanced Node B (eNodeB or eNB).

[0003] Long Term Evolution (LTE) or E-UTRAN refers to improvements of the UMTS through improved efficiency and services, lower costs, and use of new spectrum opportunities. In particular, LTE is a 3GPP standard that provides for uplink peak rates of at least 50 megabits per second (Mbps) and downlink peak rates of at least 100 Mbps. LTE supports scalable carrier bandwidths from 20 MHz down to 1.4 MHz and supports both Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD). [0004] As mentioned above, LTE may also improve spectral efficiency in networks, allowing carriers to provide more data and voice services over a given bandwidth. Therefore, LTE is designed to fulfill the needs for high-speed data and media transport in addition to high-capacity voice support. Advantages of LTE include, for example, high throughput, low latency, FDD and TDD support in the same platform, an improved end-user experience, and a simple architecture resulting in low operating costs.

[0005] Further releases of 3GPP LTE (e.g., LTE Rel-10, LTE Rel-1 1 , LTE Rel-12) are targeted towards future international mobile telecommunications advanced (IMT-A) systems, referred to herein for convenience simply as LTE-Advanced (LTE-A).

[0006] LTE-A is directed toward extending and optimizing the 3 GPP LTE radio access technologies. A goal of LTE-A is to provide significantly enhanced services by means of higher data rates and lower latency with reduced cost. LTE-A will be a more optimized radio system fulfilling the international telecommunication union-radio (ITU-R) requirements for IMT-Advanced while keeping the backward compatibility.

SUMMARY:

[0007] One embodiment is directed to a method. The method includes re -using two-bit transmit power control (TPC) in uplink (UL) grant as downlink assignment index (DAI) to indicate to a user equipment (UE) a total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release in a corresponding downlink subframe set.

[0008] Another embodiment is directed to an apparatus. The apparatus includes at least one processor and at least one memory comprising computer program code. The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to re -use two-bit transmit power control (TPC) in uplink (UL) grant as downlink assignment index (DAI) to indicate to a user equipment (UE) a total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release in a corresponding downlink subframe set.

[0009] Another embodiment is directed to a computer program, embodied on a computer readable medium, wherein the computer program is configured to control a processor to perform a process. The process includes re -using two-bit transmit power control (TPC) in uplink (UL) grant as downlink assignment index (DAI) to indicate to a user equipment (UE) a total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release in a corresponding downlink subframe set.

[00010] Another embodiment is directed to a method. The method includes providing a parameter by higher layer signaling, the parameter configured to determine an uplink (UL) downlink assignment index (DAI) indication for a given user equipment (UE) to obtain the uplink (UL) downlink assignment index (DAI).

[00011] Another embodiment is directed to an apparatus. The apparatus includes at least one processor and at least one memory comprising computer program code. The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to provide a parameter by higher layer signaling, the parameter configured to determine an uplink (UL) downlink assignment index (DAI) indication for a given user equipment (UE) to obtain the uplink (UL) downlink assignment index (DAI).

[00012] Another embodiment is directed to a computer program, embodied on a computer readable medium, wherein the computer program is configured to control a processor to perform a process. The process includes providing a parameter by higher layer signaling, the parameter configured to determine an uplink (UL) downlink assignment index (DAI) indication for a given user equipment (UE) to obtain the uplink (UL) downlink assignment index (DAI).

BRIEF DESCRIPTION OF THE DRAWINGS:

[00013] For proper understanding of the invention, reference should be made to the accompanying drawings, wherein:

[00014] Fig. 1 illustrates the seven different semi-statically configured TDD UL-DL configurations;

[00015] Fig. 2 illustrates an example of a hybrid automatic repeat request (HARQ) timing problem in case of dynamic TDD UL/DL reconfiguration;

[00016] Fig. 3a illustrates an example of UL/DL configuration 5 as DL reference configuration in TDD elMTA, according to an embodiment;

[00017] Fig. 3b illustrates an example of UL DAI timing for ACK/NACK in subframe 2 in TDD elMTA, according to an embodiment;

[00018] Fig. 3c illustrates an example of UL DAI timing for ACK/NACK in subframe 2 in TDD elMTA, according to another embodiment;

[00019] Fig. 4 illustrates an example of a flow diagram of a method, according to an embodiment;

[00020] Fig. 5a illustrates a block diagram of an apparatus, according to one embodiment; and

[00021] Fig. 5b illustrates a block diagram of an apparatus, according to another embodiment.

DETAILED DESCRIPTION:

[00022] It will be readily understood that the components of the invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of systems, methods, apparatuses, and computer program products for an uplink (UL) downlink assignment index (DAI) design and corresponding timing for TDD enhancement for interference management and traffic adaptation (elMTA), as represented in the attached figures, is not intended to limit the scope of the invention, but is merely representative of selected embodiments of the invention.

[00023] The features, structures, or characteristics of the invention described throughout this specification may be combined in any suitable manner in one or more embodiments. For example, the usage of the phrases "certain embodiments," "some embodiments," or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. Thus, appearances of the phrases "in certain embodiments," "in some embodiments," "in other embodiments," or other similar language, throughout this specification do not necessarily all refer to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Additionally, if desired, the different functions discussed below may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the described functions may be optional or may be combined. As such, the following description should be considered as merely illustrative of the principles, teachings and embodiments of this invention, and not in limitation thereof.

[00024] Embodiments of the invention relate to Rel-12 Work Item elMTA - "Further Enhancements to LTE TDD for DL-UL Interference Management and Traffic Adaptation". A goal of this elMTA work item is to realize the traffic adaptation to match the uplink and downlink traffic variation.

[00025] Currently, LTE TDD allows for asymmetric UL-DL allocations by providing seven different semi-statically configured TDD UL-DL configurations, as illustrated in Fig. 1. As illustrated in Fig. 1, subframes shown as "D" are downlink, subframes shown as "U" are uplink, and subframes shown as "S" are special. In particular, "S" is a special subframe including downlink pilot time slot (DwPTS), guard period (GP) and uplink pilot time slot (UpPTS). DwPTS can be used to transmit DL physical downlink shared channel (PDSCH). UpPTS can be used to transmit short random access channel (RACH) or sounding reference signal (SRS). GP is the switching gap from transmission to reception.

[00026] The allocations depicted in Fig. 1 can provide between 40% and 90% DL subframes. For example, if a special subframe is seen as a DL subframe, then UL-DL configuration 0 provides 4 DL subframes and 6 UL subframes. So the DL resource ratio is 40%. Similarly, it is 90% for UL-DL configuration 5.

[00027] A current mechanism for adapting UL-DL allocation is based on the system information change procedure with a 640ms period. The concrete TDD UL/DL configuration is semi-statically informed by system information block 1 (SIB-1) signaling.

[00028] Fig. 2 illustrates an example of a hybrid automatic repeat request (HARQ) timing problem in case of dynamic TDD UL/DL reconfiguration. As illustrated in Fig. 2, in case of TDD UL/DL configuration 1, when the UE receives PDSCH in DL subframe 9, it can transmit corresponding acknowledgement/non-acknowledgement (A/N) on PUCCH in UL subframe 3 in the next radio frame according to currently specified LTE HARQ timing rules. However, as illustrated in Fig. 2, if the current TDD UL/DL configuration is switched to TDD UL/DL configuration 2 to adapt to the traffic fluctuation, then subframe 3 in next radio frame will be DL subframe. Then, the UE cannot feedback A/N in subframe 3 and needs to find another uplink subframe to transmit A/N. Similar timing problem for UL PUSCH transmission.

[00029] Therefore, HARQ timing according to a reference configuration could be considered in TDD elMTA. Reference configuration usually is not the practical UL/DL configuration. It is introduced for the purpose of solving HARQ timing problem in DL and UL. The DL subframes in the DL reference configuration are a super set of the DL subframes of the previous and the adapted UL-DL configurations.. So, in Figure 2, if UL A/N can be transmitted on subframe 7 (according to UL/DL configuration 2 timing rule) for the DL subframe 9 of previous radio frame, then the HARQ timing problem can be solved. In this case, UL/DL configuration 2 is the DL reference configuration. In addition, to solve the UL PUSCH/HARQ timing problem, UL/DL configuration 0 is used as UL reference configuration since UL subframes of UL/DL configuration 0 are super set of other UL/DL configurations. Therefore, separate reference configurations are used for DL and UL.

[00030] Since all seven existing TDD UL/DL configurations can be dynamically selected for TDD elMTA, UL/DL configurations 0 and 5 are used as UL reference configuration and DL reference configuration due to the characteristic of the UL-heaviest configuration and the DL-heaviest configuration, respectively. However, this approach causes a UL DAI/UL index ambiguity problem because in UL grant, UL index and UL DAI are occupying the same two bits and interpreted dependent on the UL/DL configuration, which is explained in 3GPP TS36.212 for downlink control information (DCI) format 0/4. The UL index may be 2 bits and can be present only for TDD operation with uplink-downlink configuration 0. The UL index may be used to schedule multiple physical uplink shared channel(s) (PUSCH) if current UL-DL configuration is configuration 0. The DAI may be 2 bits and can be present for TDD operation with uplink-downlink configurations 1-6.

[00031] For TDD UL/DL configuration 0 and normal HARQ operation, t he UE may, upon detection of a physical downlink control channel (PDCCH ) with DCI format 0/4 in subframe n intended for the UE, adjust the correspo nding PUSCH transmission in subframe n+k if the MSB of the UL index in t he DCI format 0/4 is set to 1 with k given in Table 8-2 in 3 GPP TS36.213. I f, for TDD UL/DL configuration 0 and normal HARQ operation, the LSB of the UL index in the DCI format 0/4 is set to 1 in subframe n, the UE may ad just the corresponding PUSCH transmission in subframe n+7. If, for TDD UL/DL configuration 0, both the MSB and LSB of the UL index in the DCI format 0/4 are set in subframe n, the UE may adjust the corresponding PUS CH transmission in both subframes n+ k and n+7, with k given in Table 8-2 in 3GPP TS36.213.

[00032] For TDD UL-DL configurations 1 -6, the value of the DAI in DCI format 0/4, detected by the UE (according to 3 GPP TS36.213 Table 7.3-X) in subframe - where is defined in 3 GPP TS36.213 Table 7.3-Y, represents the total number of subframes with PDSCH transmissions and with PDCCH indicating downlink semi-persistent scheduling (SPS) release to the corresponding UE within all the subframe(s) " ^{~ k} , where ^{k G K} . The value yUL

includes all PDSCH transmission with and without corresponding PDCCH within all the subframe(s) ^{n ~ k} . In case neither PDSCH transmission nor PDCCH indicate the downlink SPS resource release is intended to the UE, yUL the UE can expect that the value of the DAI in DCI format 0/4, ^V DM ^ if transmitted, is set to 4.

[00033] Since UL/DL configuration 0 is used as UL reference configuration, in UL grant, UL index is used to schedule multiple UL subframes in one UL grant. So there is no UL DAI if current UL reference configuration is configuration 0.

[00034] UL DAI has been specified since LTE Rel-8 for the purpose of DL receiving validation and A/N codebook size determination, where codebook refers to the A/N bit stream. Without UL DAI, the number of DL subframes scheduled for UE lacks of validation at UE side and the codebook size is defined as the largest bundle window (i.e., M=9 for UL/DL configuration 5 as DL reference configuration, where M is the size of this DL subframe set of UL/DL configuration 5). Thus, not only DL error case will be caused but also too much overhead will be carried on PUSCH. In view of the above, the problem of missing UL DAI needs to be solved.

[00035] It is noted that bundle window refers to the DL subframe set. The A/N corresponding to all the DL subframes within this DL subframe set are transmitted in one UL subframe because in most of UL-DL configurations, there are more DL subframes than UL. Based on the above, embodiments relate to UL DAI design and corresponding timing for TDD elMTA.

[00036] According to an embodiment, it is assumed that UL/DL configuration 5 and 0 are used as DL reference configuration and UL reference configuration, respectively. As a result, there is no UL DAI in UL grant scheduling. The straightforward solution is to introduce two new bits as UL DAI in DCI format 0/4. However, this will introduce a new DCI format. Besides this, another solution is to indicate UL/DL configuration 6 in SIB-1 signaling so that UL DAI is always contained in DCI format 0/4 with slight performance loss in UL.

[00037] As mentioned above, certain embodiments provide solutions to the problem of missing UL DAI for TDD elMTA. In some embodiments, configuration 0 is used as UL reference configuration. One embodiment for UL DAI introduction includes re -using two-bit transmit power control (TPC) in UL grant as UL DAI to indicate the total number of subframes with PDSCH transmissions and with PDCCH indicating downlink SPS release to the UE within all the subframe(s) in the corresponding bundle window. DL SPS release refers to where one PDCCH is used to release DL SPS service. In this embodiment, DCI format 3/3A is transmitted with the UL grant in this DL subframe to indicate the absolute UL transmission power adjustment for PUSCH.

[00038] Another embodiment for UL DAI introduction includes providing one new parameter, for example named DAI-tpc-index, by high layer signaling to determine the index to the UL DAI indication for a given UE to obtain UL DAI. In one example, the DCI format 3 may be transmitted in the same DL subframe with UL grant scheduling. Alternatively, in an embodiment, in DCI format 3, the index determined by the existing parameter tpc-Index can be reused to indicate UL DAI for a given UE. The DCI format 3 may be transmitted in the same DL subframe with UL grant scheduling.

[00039] One embodiment for a new UL DAI timing includes, when DCI format 0/4 is transmitted in DL subframe 5/6 to schedule UL subframe 2 in a next radio frame, the value of UL DAI, detected by the UE in subframe 5/6, represents the total number of subframes with PDSCH transmissions and with PDCCH indicating downlink SPS release to the corresponding UE within the subframe set from DL subframe 9 of previous radio frame to subframe 5/6 of current radio frame plus the number of possible DL subframe 6, 7, 8 or 7, 8 to be scheduled in current radio frame. Since explicit UL/DL configuration is indicated, eNB and UE can know the transmission direction of subframe 6, 7 and 8 so that the maximum number of possible DL subframes can be obtained by excluding the UL subframes when subframe 7 and 8 are used for UL transmission.

[00040] Another embodiment for a new UL DAI timing includes, when DCI format 0/4 is transmitted in DL subframe 5/6 to schedule UL subframe 2 in a next radio frame, the value of UL DAI, detected by the UE in subframe 5/6, represents the total number of subframes with PDSCH transmissions and with PDCCH indicating downlink SPS release to the corresponding UE within the subframe set from DL subframe 6/7 of previous radio frame to subframe 5/6 of current radio frame.

[00041] At the UE side, upon receiving the DCI format 0/4 in DL subframe 5/6 to schedule PUSCH in subframe 2, the UE may first detect the value of UL DAI, validate the DL receiving with the detected UL DAI within the subframe set corresponding to UL DAI timing, and then generate ACK NACK codebook on PUSCH according to UL DAI. Here, validating means UE compares the value of detected UL DAI with the number of practical received DL subframes within the corresponding downlink subframe set. In this way, UE can know whether DL assignment has been missed.

[00042] As mentioned above, according to embodiments, two approaches are provided to solve the problem of the missing UL DAI. One embodiment includes reusing two-bit TPC in UL grant as UL DAI to indicate the total number of subframes with PDSCH transmissions and with PDCCH indicating downlink SPS release to the UE within all the subframe(s) in the corresponding bundle window. According to an embodiment, DCI format 3/3A may be transmitted with the UL grant in the same DL subframe to indicate the absolute UL transmission power adjustment for PUSCH. [00043] In another embodiment, a new parameter, which may for example be named DAI-tpc-index, is provided by high layer signalling to determine the index to the UL DAI indication for a given UE to obtain UL DAI. In an embodiment, the DCI format 3 is transmitted in the same DL subframe with UL grant scheduling to provide UL DAI by two bits in DCI format 3 for a given UE. Alternatively, the index determined by the existing parameter tpc-Index can be reused to indicate UL DAI for a given UE.

[00044] As also mentioned above, other embodiments can solve the problem of UL DAI timing and corresponding bundle window. Fig. 3a illustrates an example of UL/DL configuration 5 as DL reference configuration in TDD elMTA, according to an embodiment. As illustrated in Figure 3 a, where TDD UL/DL configuration 5 is DL reference configuration, if the UE receives PDSCH in the subframe set from DL subframe 9 of the previous radio frame to DL subframe 8 of the current radio frame, and there is UL grant to schedule PUSCH in UL subframe 2, the UE may transmit corresponding A/N on PUSCH in UL subframe 2 in the next radio frame according to currently specified LTE HARQ timing rules, which is plotted by the circle illustrated in Fig. 3a.

[00045] It is noted that UL grant is transmitted in DL subframe 8 according to UL DAI timing of UL/DL configuration 5. However, considering the TDD UL/DL configuration 0 is used as UL reference configuration, multi-TTI scheduling can be used in one UL grant to schedule two UL subframes. For example, in Fig. 3b, UL grant in DL subframe 5 may be used to schedule UL subframe 2 by means of setting the LSB of UL index to "1". If the UL DAI timing for DL/UL configuration 5 is continued to be used as shown in the circle 301 in Fig. 3b, then the value of UL DAI in DL subframe 5 represents the subframe set from DL subframe 9 of the previous radio frame to current DL subframe 5 and also the possible DL subframe 6, 7, 8 to be scheduled as shown by circle 302. Since subframe 6 is always used for DL and explicit UL/DL configuration is indicated to the UE, the UE and eNB are aware of whether the subframe 7 and 8 are used for DL. Then, the maximum number of DL subframes to be scheduled for the UE can be obtained. Then UL DAI is indicated to UE by setting its value to the number of practically transmitted DL subframes within the DL subframe set from Subframe 9 of previous radio frame to current DL subframe sending UL grant plus the number of practical DL subframes from Subframe 6 to Subframe 8 in current radio frame as shown in circle 302. In this scheme, the eNB may need to predict whether subframe 6, 7, 8 shall be scheduled for UE.

[00046] Fig. 3c illustrates an example of UL DAI timing for ACK/NACK in Subframe 2 in TDD elMTA. In this embodiment of the UL DAI timing approach, when DCI format 0/4 is transmitted in DL subframe 5/6 to schedule UL subframe 2 in a next radio frame, the value of UL DAI, detected by the UE in subframe 5/6, represents the total number of subframes with PDSCH transmissions and PDCCH indicates downlink SPS release to the corresponding UE within the subframe set from DL subframe 6/7 of the previous radio frame to subframe 5/6 of the current radio frame, as shown in circle 305 of Fig. 3c.

[00047] Fig. 4 illustrates an example flow diagram of the operations at the UE side. In this embodiment, upon receiving the DCI format 0/4 in DL subframe 5/6 to schedule PUSCH in subframe 2, the UE first detects the value of UL DAI at 400. The UE, at 410, validates the DL receiving with the detected UL DAI within the subframe set corresponding to UL DAI timing and, at 420, generates the ACK/NACK codebook on PUSCH according to UL DAI. In an embodiment, at 430, the UE may transmit the ACK/NACK on PUSCH.

[00048] Fig. 5a illustrates an example of an apparatus 10 according to an embodiment. In one embodiment, apparatus 10 may be a network element, such as a base station or eNB. Further, it should be noted that one of ordinary skill in the art would understand that apparatus 10 may include components or features not shown in Fig. 5a. Only those components or features necessary for illustration of the invention are depicted in Fig. 5a.

[00049] As illustrated in Fig. 5a, apparatus 10 includes a processor 22 for processing information and executing instructions or operations. Processor 22 may be any type of general or specific purpose processor. While a single processor 22 is shown in Fig. 5a, multiple processors may be utilized according to other embodiments. In fact, processor 22 may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples.

[00050] Apparatus 10 further includes a memory 14, which may be coupled to processor 22, for storing information and instructions that may be executed by processor 22. Memory 14 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and removable memory. For example, memory 14 can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, or any other type of non- transitory machine or computer readable media. The instructions stored in memory 14 may include program instructions or computer program code that, when executed by processor 22, enable the apparatus 10 to perform tasks as described herein.

[00051] Apparatus 10 may also include one or more antennas 25 for transmitting and receiving signals and/or data to and from apparatus 10. Apparatus 10 may further include a transceiver 28 configured to transmit and receive information. For instance, transceiver 28 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 25 and demodulate information received via the antenna(s) 25 for further processing by other elements of apparatus 10. In other embodiments, transceiver 28 may be capable of transmitting and receiving signals or data directly.

[00052] Processor 22 may perform functions associated with the operation of apparatus 10 including, without limitation, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 10, including processes related to management of communication resources.

[00053] In an embodiment, memory 14 stores software modules that provide functionality when executed by processor 22. The modules may include, for example, an operating system that provides operating system functionality for apparatus 10. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 10. The components of apparatus 10 may be implemented in hardware, or as any suitable combination of hardware and software.

[00054] In one embodiment, apparatus 10 may be a base station in a communications network, such as an eNB in LTE. In an embodiment, apparatus 10 may be controlled by memory 14 and processor 22 to re -use two-bit transmit power control (TPC) in uplink (UL) grant as downlink assignment index (DAI) to indicate to a user equipment (UE) a total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release within all the subframes in a corresponding bundle window. According to this embodiment, apparatus 10 may be further controlled by memory 14 and processor 22 to transmit downlink control information (DCI) format 3/3A with the uplink (UL) grant to indicate an absolute uplink (UL) transmission power adjustment for a physical uplink shared channel (PUSCH).

[00055] In another embodiment, apparatus 10 may be controlled by memory 14 and processor 22 to provide a parameter by higher layer signaling, the parameter configured to determine an index to an uplink (UL) downlink assignment index (DAI) indication for a given user equipment (UE) to obtain the uplink (UL) downlink assignment index (DAI). According to an embodiment, the parameter is a new parameter, e.g., DAI-tpc-index. Alternatively, in downlink control information (DCI) format 3, apparatus 10 may be controlled by memory 14 and processor 22 to re -use an index determined by an existing parameter, e.g., tpc-Index, to indicate the uplink (UL) downlink assignment index (DAI) for the given user equipment (UE). In an embodiment, apparatus 10 may be controlled by memory 14 and processor 22 to transmit the downlink control information (DCI) format 3 in a same downlink (DL) subframe with uplink (UL) grant scheduling.

[00056] In some embodiments, when downlink control information (DCI) format 0/4 is transmitted in downlink (DL) subframe 5/6 to schedule uplink (UL) subframe 2 in a next radio frame, apparatus 10 may be controlled by memory 14 and processor 22 to configure or set a value of downlink assignment index (DAI) in the uplink (UL) grant to represent the total number of practically transmitted downlink subframes within the subframe set from subframe 9 of a previous radio frame to subframe 5/6 of a current radio frame plus a number of possible downlink (DL) subframe 6, 7, 8 or 7, 8 to be scheduled in the current radio frame.

[00057] In other embodiments, when downlink control information (DCI) format 0/4 is transmitted in downlink (DL) subframe 5/6 to schedule uplink (UL) subframe 2 in a next radio frame, apparatus 10 may be controlled by memory 14 and processor 22 to configure or set a value of downlink assignment index (DAI) in the uplink (UL) grant to represent the total number of practically transmitted downlink subframes within the subframe set from subframe 6/7 of a previous radio frame to subframe 5/6 of a current radio frame.

[00058] Fig. 5b illustrates an example of an apparatus 20 according to another embodiment. In an embodiment, apparatus 20 may be a mobile device, such as a UE. It should be noted that one of ordinary skill in the art would understand that apparatus 20 may include components or features not shown in Fig. 5b. Only those components or features necessary for illustration of the invention are depicted in Fig. 5b.

[00059] As illustrated in Fig. 5b, apparatus 20 includes a processor 32 for processing information and executing instructions or operations. Processor 32 may be any type of general or specific purpose processor. While a single processor 32 is shown in Fig. 4b, multiple processors may be utilized according to other embodiments. In fact, processor 32 may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples.

[00060] Apparatus 20 further includes a memory 34, which may be coupled to processor 32, for storing information and instructions that may be executed by processor 32. Memory 34 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and removable memory. For example, memory 34 can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, or any other type of non- transitory machine or computer readable media. The instructions stored in memory 34 may include program instructions or computer program code that, when executed by processor 32, enable the apparatus 20 to perform tasks as described herein.

[00061] Apparatus 20 may also include one or more antennas 35 for transmitting and receiving signals and/or data to and from apparatus 20. Apparatus 20 may further include a transceiver 38 configured to transmit and receive information. For instance, transceiver 38 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 35 and demodulate information received via the antenna(s) 35 for further processing by other elements of apparatus 20. In other embodiments, transceiver 38 may be capable of transmitting and receiving signals or data directly.

[00062] Processor 32 may perform functions associated with the operation of apparatus 20 including, without limitation, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 20, including processes related to management of communication resources.

[00063] In an embodiment, memory 34 stores software modules that provide functionality when executed by processor 32. The modules may include, for example, an operating system that provides operating system functionality for apparatus 20. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 20. The components of apparatus 20 may be implemented in hardware, or as any suitable combination of hardware and software. [00064] As mentioned above, according to one embodiment, apparatus 20 may be UE. In this embodiment, apparatus 20 may be controlled by memory 34 and processor 32 to detect a value of an uplink (UL) downlink assignment index (DAI) received in a downlink (DL) subframe, validate downlink (DL) receiving with the detected uplink (UL) downlink assignment index (DAI), and generate acknowledgement/non-acknowledgement codebook according to the uplink (UL) downlink assignment index (DAI).

[00065] In some embodiments, the functionality of any of the methods described herein, such as those illustrated in Fig. 4 discussed above, may be implemented by software and/or computer program code stored in memory or other computer readable or tangible media, and executed by a processor. In other embodiments, the functionality may be performed by hardware, for example through the use of an application specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software.

[00066] One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention. In order to determine the metes and bounds of the invention, therefore, reference should be made to the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A method, comprising:

re -using two-bit transmit power control (TPC) in uplink (UL) grant as downlink assignment index (DAI) to indicate to a user equipment (UE) a total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release in a corresponding downlink subframe set.

2. A method according to claim 1, wherein the downlink subframe set is the set whose corresponding acknowledgement/non-acknowledgement (ACK/NACK) is transmitted in one UL subframe.

3. The method according to claim 1, further comprising transmitting downlink control information (DCI) format 3/3A with the uplink (UL) grant to indicate an absolute uplink (UL) transmission power adjustment for a physical uplink shared channel (PUSCH).

4. The method according to claim 1, 2 or 3, wherein, when downlink control information (DCI) format 0/4 is transmitted in downlink (DL) subframe 5/6 to schedule uplink (UL) subframe 2 in a next radio frame, configuring a value of the downlink assignment index (DAI) to represent the total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release within the subframe set from subframe 9 of a previous radio frame to subframe 5/6 of a current radio frame plus a number of possible downlink (DL) subframe 6, 7, 8 or 7, 8 to be scheduled in the current radio frame.

5. The method according to claim 1, 2 or 3, wherein, when downlink control information (DCI) format 0/4 is transmitted in downlink (DL) subframe 5/6 to schedule uplink (UL) subframe 2 in a next radio frame, configuring a value of the downlink assignment index (DAI) to represent the total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release within the subframe set from subframe 6/7 of a previous radio frame to subframe 5/6 of a current radio frame.

6. An apparatus, comprising:

at least one processor; and

at least one memory comprising computer program code,

wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to re -use two-bit transmit power control (TPC) in uplink (UL) grant as downlink assignment index (DAI) to indicate to a user equipment (UE) a total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release in a corresponding downlink subframe set.

7. An apparatus according to claim 6, wherein the downlink subframe set is the set whose corresponding acknowledgement/non-acknowledgement (ACK/NACK) is transmitted in one UL subframe.

8. The apparatus according to claim 6, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to transmit downlink control information (DCI) format 3/3A with the uplink (UL) grant to indicate an absolute uplink (UL) transmission power adjustment for a physical uplink shared channel (PUSCH).

9. The apparatus according to claim 6, 7 or 8, wherein, when downlink control information (DCI) format 0/4 is transmitted in downlink (DL) subframe 5/6 to schedule uplink (UL) subframe 2 in a next radio frame, the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to configure a value of the downlink assignment index (DAI) to represent the total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release within the subframe set from subframe 9 of a previous radio frame to subframe 5/6 of a current radio frame plus a number of possible downlink (DL) subframe 6, 7, 8 or 7, 8 to be scheduled in the current radio frame.

10. The apparatus according to claim 6, 7, or 8 wherein, when downlink control information (DCI) format 0/4 is transmitted in downlink (DL) subframe 5/6 to schedule uplink (UL) subframe 2 in a next radio frame, the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to configure a value of the downlink assignment index (DAI) to represent the total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release within the subframe set from subframe 6/7 of a previous radio frame to subframe 5/6 of a current radio frame.

1 1. A computer program, embodied on a computer readable medium, wherein the computer program, when executed by a processor, is configured to control the processor to perform a method according to any one of claims 1-5.

12. A method, comprising:

providing a parameter by higher layer signaling, the parameter configured to determine an uplink (UL) downlink assignment index (DAI) indication for a given user equipment (UE) to obtain the uplink (UL) downlink assignment index (DAI).

13. The method according to claim 12, wherein the providing comprising providing a new parameter.

14. The method according to claim 12, wherein, in downlink control information (DCI) format 3, the providing comprises re -using an index determined by an existing parameter to indicate the uplink (UL) downlink assignment index (DAI) for the given user equipment (UE).

15. The method according to any one of claims 12-14, further comprising transmitting the downlink control information (DCI) format 3 in a same downlink (DL) subframe with uplink (UL) grant scheduling.

16. The method according to any one of claims 12-15, wherein, when downlink control information (DCI) format 0/4 is transmitted in downlink (DL) subframe 5/6 to schedule uplink (UL) subframe 2 in a next radio frame, configuring a value of the uplink (UL) downlink assignment index (DAI) to represent the total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release within the subframe set from subframe 9 of a previous radio frame to subframe 5/6 of a current radio frame plus a number of possible downlink (DL) subframe 6, 7, 8 or 7, 8 to be scheduled in the current radio frame.

17. The method according to any one of claims 12-15, wherein, when downlink control information (DCI) format 0/4 is transmitted in downlink (DL) subframe 5/6 to schedule uplink (UL) subframe 2 in a next radio frame, configuring a value of the uplink (UL) downlink assignment index (DAI) to represent the total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release within the subframe set from subframe 6/7 of a previous radio frame to subframe 5/6 of a current radio frame.

18. An apparatus, comprising:

at least one processor; and

at least one memory comprising computer program code,

wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to provide a parameter by higher layer signaling, the parameter configured to determine an uplink (UL) downlink assignment index (DAI) indication for a given user equipment (UE) to obtain the uplink (UL) downlink assignment index (DAI).

19. The apparatus according to claim 18, wherein the parameter comprises a new parameter.

20. The apparatus according to claim 18, wherein, in downlink control information (DCI) format 3, the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to re -use an index determined by an existing parameter to indicate the uplink (UL) downlink assignment index (DAI) for the given user equipment (UE).

21. The apparatus according to any one of claims 18-20, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to transmit the downlink control information (DCI) format 3 in a same downlink (DL) subframe with uplink (UL) grant scheduling.

22. The apparatus according to any one of claims 18-21, wherein, when downlink control information (DCI) format 0/4 is transmitted in downlink (DL) subframe 5/6 to schedule uplink (UL) subframe 2 in a next radio frame, the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to configure a value of the uplink (UL) downlink assignment index (DAI) to represent the total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release within the subframe set from subframe 9 of a previous radio frame to subframe 5/6 of a current radio frame plus a number of possible downlink (DL) subframe 6, 7, 8 or 7, 8 to be scheduled in the current radio frame.

23. The apparatus according to any one of claims 18-21, wherein, when downlink control information (DCI) format 0/4 is transmitted in downlink (DL) subframe 5/6 to schedule uplink (UL) subframe 2 in a next radio frame, the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to configure a value of the uplink (UL) downlink assignment index (DAI) to represent the total number of subframes with physical downlink shared channel (PDSCH) transmissions and with physical downlink control channel (PDCCH) indicating downlink semi-persistent scheduling (SPS) release within the subframe set from subframe 6/7 of a previous radio frame to subframe 5/6 of a current radio frame.

24. A computer program, embodied on a computer readable medium, wherein the computer program, when executed by a processor, is configured to control the processor to perform a method according to any one of claims 12-17.

25. A method, comprising:

detecting a value of an uplink (UL) downlink assignment index (DAI) received in a downlink (DL) subframe ;

validating downlink (DL) receiving with the detected uplink (UL) downlink assignment index (DAI); and

generating acknowledgement/non-acknowledgement codebook according to the uplink (UL) downlink assignment index (DAI).

26. An apparatus, comprising:

at least one processor; and

at least one memory comprising computer program code,

wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to detect a value of an uplink (UL) downlink assignment index (DAI) received in a downlink (DL) subframe;

validate downlink (DL) receiving with the detected uplink (UL) downlink assignment index (DAI); and

generate acknowledgement/non-acknowledgement codebook according to the uplink (UL) downlink assignment index (DAI).

27. A computer program, embodied on a computer readable medium, wherein the computer program, when executed by a processor, is configured to control the processor to perform a method according to claim 23.