Methods, apparatuses, and computer program products for scheduling delays associated with harq processes in lte-mtc

Abstract

The present application relates generally to wireless communication technology. More particularly, it relates to a method and apparatus for scheduling a delay associated with HARQ process in LTE-MTC. It also relates to a computer program product adapted for the same purpose. According to one embodiment, a method for scheduling a delay associated with HARQ process in LTE-MTC comprises: -a) determining a HARQ-ACK scheduling counting strategy in response to the presence or absence of PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps; -b) scheduling a HARQ-ACK delay value according to the HARQ-ACK scheduling counting strategy.

Description

TECHNICAL FIELD

[0001] The present application relates generally to wireless communication technology. More specifically, the present application relates to a method and apparatus for scheduling delays associated with HARQ processes in LTE-MTC. The present application also relates to a computer program product adapted for the same purpose. BACKGROUND

[0002] At the 86th plenary RAN meeting, a new work item (WI) entitled “Rel-17 enhancements for NB-IoT and LTE-MTC” was agreed. One of the objectives therein includes specifying for LTE-MTC the introduction of 14 HARQ processes in DL, as described in the work item description (WID): Support of additional PDSCH scheduling delay for introduction of 14-HARQ processes in DL, for HD-FDD Cat M1 UEs.

[0003] [LTE-MTC] [RAN1]

[0004] The WID objective for LTE-MTC targets HD-FDD Cat M1 UEs, whose peak data rate can be achieved by using 10 HARQ processes and HARQ-ACK bundling in combination, as shown in Figure 1 .

[0005] In Figure 1 , the solid and dashed arrows show examples of “PDSCH scheduling delay” (containing 2 subframes) and “HARQ-ACK delay” (containing 11 subframes), respectively.

[0006] The Rel-17 enhancements for LTE-MTC aim at increasing the peak data rate by “Support of additional PDSCH scheduling delay for introduction of 14-HARQ processes in DL, for HD-FDD Cat M1 UEs”, which is aimed at being accomplished by using the framework described in Figure 2 . Figure 1

[0007] In Figure 2 , the solid and dashed arrows show examples of “PDSCH scheduling delay” (containing 7 subframes) and “HARQ-ACK delay” (containing 13 subframes), respectively.

[0008] ​With respect to the introduction of 14 HARQ processes in the DL, it is written: "Assuming a TBS of 1000 bits transmitted in each PDSCH, the peak data rate achieved by this scheduling is (10 x 1000) / 17 = 588 kbps. In this contribution, we propose to increase the peak data rate to (12 x 1000) / 17 = 706 kbps (20% increase) by allowing data scheduling in subframes 0 and 1." See R1-1912694, "Increased peak data rate for HD-FDD MTC UEs," Qualcomm Incorporated, Orange, Sierra Wireless, Verizon, Ericsson, Sequans, Nokia, Nokia Shanghai Bell, RAN1#99, Reno, USA, November 18th - 22nd, 2019, which is incorporated by reference herein in its entirety.

[0009] While the increase in peak data rate is estimated using 12 HARQ processes, there are a total of 14 HARQ processes. As shown in Figure 2 the reason for having 14 HARQ processes (i.e., spanning from #0 to #13) is that HARQ processes #10 and #11 (bound to MPDCCH 10 and 11) need to wait for ACK bundling after the upcoming set of MPDCCH ending with HARQ processes #12 and #13 (bound to MPDCCH 12 and 13).

[0010] As can be seen from Figure 2 , the introduction of 14 HARQ processes in the DL will require the addition of new values for both "PDSCH scheduling delay" and "HARQ-ACK delay".

[0011] In the legacy scheme with 10-HARQ processes, "PDSCH scheduling delay" uses the value 2. That is, the PDSCH starts on the second subframe after the end of the MPDCCH used to schedule the corresponding DL data. On the other hand, when there are 14 HARQ processes, "PDSCH scheduling delay" needs a value equal to 7 in addition to the legacy value equal to 2 (see Figure 2 ).

[0012] In R1-1912694, “Increased peak data rate for HD-FDD MTC UE”, Qualcomm Incorporated, Orange, Sierra Wireless, Verizon, Ericsson, Samsung, Nokia, Nokia Shanghai Bell, 3GPP TSG RAN WG1 Meeting #99, Reno, USA, 18-22 November 2019, it is proposed that “PDSCH scheduling delay” can support a value of 7 in addition to the legacy value of 2, while for “HARQ-ACK delay”, it is proposed to use the following values: 4, 5, 6, 7, 9, 11, 13, 15.

[0013] Regarding HARQ-ACK delay, it is described in current 3GPP specifications. Specifically, the HARQ-ACK delay for BL / CE UEs in CE Mode A is shown in Table 1 below:

[0014] Table 1: HARQ-ACK delay for BL / CE UEs in CE Mode A

[0015]

[0016] See 3GPP specification TS 36.213, “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Layer Procedures”, version 16.2.0, for details, which is incorporated by reference herein in its entirety. The current specification allows up to 10 HARQ processes in FDD, and as can be seen from the above table, the maximum HARQ-ACK delay for ‘ce-HARQ-AckBundling’ is 11. SUMMARY

[0017] One of the objectives in the WI on “Rel-17 enhancements for NB-IoT and LTE-MTC” is to introduce “14-HARQ processes in DL for HD-FDD Cat M1 UEs”, for which the envisaged issues of support are as follows:

[0018] • The proposal to introduce “14-HARQ processes in DL for HD-FDD Cat M1 UEs” does not take into account the further delay that results when this feature happens to coexist with other scenarios / features, which would impact the HARQ-ACK delay.

[0019] • Depending on the scenario in which the 14-HARQ processes feature is intended to be used, there would be a need to use specific HARQ-ACK delay values.

[0020] According to one aspect of the disclosure, the selective HARQ-ACK delay counting strategy has been described in the form of tables providing delays associated with PUCCHs (e.g., PUCCH#0, PUCCH#1 and PUCCH#2) when "HARQ-ACK bundling for 14 HARQ processes in DL for Cat M1 HD-FDD UEs" exists in the following cases:

[0021] • PUCCH repetition, invalid BL / CE DL subframe and invalid BL / CE UL subframe.

[0022] • PUCCH repetition, invalid BL / CE DL subframe, invalid BL / CE UL subframe and measurement gap (MG).

[0023] In the present disclosure, the term "invalid BL / CE DL subframe" corresponds to the term "non-BL / CE DL subframe" in 3GPP technical specifications.

[0024] The solutions described in the present disclosure are backward compatible with 3GPP standards since they exploit existing frameworks (e.g., BL / CE DL subframe) to create a selective HARQ-ACK delay counting strategy.

[0025] According to one embodiment, a method for scheduling delays associated with HARQ processes in LTE-MTC comprises:

[0026] a) determining a HARQ-ACK scheduling counting strategy in response to the presence or absence of PUCCH repetition, invalid BL / CE DL subframe, invalid BL / CE UL subframe and measurement gap; and

[0027] b) scheduling a HARQ-ACK delay value according to the HARQ-ACK scheduling counting strategy.

[0028] According to another embodiment, a method for scheduling delays associated with HARQ processes in LTE-MTC comprises the following steps performed by a UE:

[0029] a) receiving a HARQ-ACK delay value; and

[0030] b) transmitting a PUCCH subframe for HARQ-ACK or HARQ-NACK with the HARQ-ACK delay value,

[0031] wherein the HARQ-ACK delay value is scheduled according to a HARQ-ACK scheduling counting strategy determined in response to the presence or absence of PUCCH repetition, invalid BL / CE DL subframe, invalid BL / CE UL subframe and measurement gap.

[0032] According to another embodiment, an apparatus for scheduling a delay associated with HARQ processes in LTE-MTC comprises:

[0033] a storage device configured to store a computer program comprising computer instructions; and

[0034] a processor coupled to the storage device and configured to execute the computer instructions to perform the method as described above.

[0035] According to another embodiment, a computer program product for scheduling a delay associated with HARQ processes in LTE-MTC, the computer program product being embodied in a computer readable storage medium and comprising computer instructions for performing the method as described above. BRIEF DESCRIPTION OF DRAWINGS

[0036] The foregoing and other objects, features and advantages will be apparent from the following more particular description of preferred embodiments as illustrated in the accompanying drawings in which:

[0037] Figure 1 The combined use of 10 HARQ processes and HARQ-ACK bundling for Cat M1 HD-FDD UEs is schematically illustrated.

[0038] Figure 2 The combined use of 14 HARQ processes and HARQ-ACK bundling for Cat M1 HD-FDD UEs is schematically illustrated.

[0039] Figure 3 A flowchart schematically illustrating a method for scheduling a delay associated with HARQ processes in LTE-MTC according to an embodiment of the application is shown.

[0040] Figure 4 is a block diagram illustrating an apparatus for scheduling a delay associated with HARQ processes in LTE-MTC according to another embodiment.

[0041] Figure 5 A flowchart schematically illustrating a method for scheduling a delay associated with HARQ processes in LTE-MTC according to an embodiment of the application is shown.

[0042] Figure 6 is a block diagram illustrating an apparatus for scheduling a delay associated with HARQ processes in LTE-MTC according to another embodiment.

[0043] Figures 7-9 Some examples of insufficient HARQ-ACK delay values are schematically illustrated.

[0044] Figures 10-12 Some examples of using a selective HARQ-ACK delay count strategy are illustrated schematically. DETAILED DESCRIPTION

[0045] The present application can be implemented in numerous ways, including as a process; an apparatus; a system; a composition of matter; a computer program product (which can be stored on a computer-readable storage medium... and / or a processor, such as a processor configured to execute instructions stored on and / or provided by a memory coupled to the processor). In this specification, these implementations, or any other form that the application can take, can be referred to as techniques. In general, the order of the steps of disclosed processes can be altered within their scopes. Unless otherwise specified, an element described in association with one embodiment can also be used in association with another embodiment unless otherwise specified. Unless explicitly stated, elements (such as a processor or memory element described as being configured to perform a task should be interpreted in either of two ways. Either the element is configured (typically electronically) to perform the task or the element has typically been manufactured to perform the task (e.g., a processor designed to perform specific tasks or a memory designed to store specific instructions). As used herein, the term "processor" refers to one or more devices, circuits, and / or processing cores configured to process data (e.g., computer program instructions). The term is used in this disclosure in connection with a "computer" or "processing machine" only to refer to a device that can process data under the control of one or more computer programs stored on a computer-readable medium. The term processor is not limited to just one type of device, circuit, or processing core, nor does it imply that the apparatus only contains a single device, circuit, or processing core. Rather the term processor means that the apparatus includes any suitable device, circuit, or processing core and that such device, circuit, or processing core can be implemented in one or more physical devices, circuits, or processing cores. The term processor can refer to a single, integrated, or dedicated device, circuit, or processing core or it can refer to two or more individual components working together. Similarly, the term "computer-readable medium" refers to one or more physical devices, components, and / or media that store instructions and / or data for execution by a computer. The instructions can be stored in various places affiliated with the physical devices, components, and / or media, such as one or more internal registers and / or memories. The instructions can also be stored on a computer-readable storage medium belonging to the physical devices, components, and / or media. As used in this disclosure, the term "computer program product" refers to one or more computer programs and computer-readable media. The term "system" refers to both hardware and software components that are utilized to implement the techniques. The term "software" refers to computer-readable instructions, programs, and data that are used to program the processor(s) to implement the techniques. The term "hardware" refers to the physical hardware components used to implement the techniques.

[0046] Furthermore, use of the terms "first", "second", "third", etc., in the claims to mean "one", "another", "yet another", or "an additional" does not imply that the claims require these elements to proceed in a particular order, or that one element is prior to or precedes another element, or that the method of the claims requires any particular chronological order of actions. Rather, these terms are simply used to distinguish between different elements or steps in the claims.

[0047] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0048] The principles of the application are illustrated in the accompanying drawings and Figure 1A detailed description of one or more embodiments of the present invention is provided below. The present invention is described in conjunction with these embodiments, but the invention is not limited to any embodiment. The scope of the present invention is limited only by the claims, and the invention encompasses many alternatives, modifications, and equivalents. In order to provide a thorough understanding of the present invention, many specific details are set forth in the following description. These details are provided for illustrative purposes, and the present invention can be practiced according to the claims without some or all of these specific details. For the sake of clarity, technical material known in the technical field related to the present invention has not been described in detail to avoid unnecessarily obscuring the present invention.

[0049] Figure 3 FIG. 4 is a flow chart of a method 300 for scheduling delays associated with HARQ processes in LTE-MTC according to an embodiment of the present invention.

[0050] like Figure 3 As shown, the flow chart includes the following steps, for example, performed on the NodeB side:

[0051] Step 301: Determine a HARQ-ACK scheduling count policy in response to the presence or absence of PUCCH repetition, invalid BL / CE DL subframe, invalid BL / CE UL subframe, and measurement gap.

[0052] Step 302: Schedule the HARQ-ACK delay value according to the HARQ-ACK scheduling count policy.

[0053] In this embodiment, preferably, the flowchart further includes a step of sending a DCI including a HARQ-ACK delay value to the UE.

[0054] In this embodiment, preferably, the HARQ-ACK delay value is represented as one multi-bit value among a plurality of multi-bit values ​​stored in the HARQ-ACK delay table.

[0055] In this embodiment, preferably, determining the HARQ-ACK scheduling counting strategy includes the following steps: selecting one of multiple candidate HARQ-ACK delay counting strategies as the HARQ-ACK scheduling counting strategy based on the presence or absence of PUCCH repetition, invalid BL / CE DL subframe, invalid BL / CE UL subframe and measurement gap.

[0056] In this embodiment, preferably, in the presence of PUCCH repetition, invalid BL / CE DL subframes and invalid BL / CE UL subframes, when 14 HARQ processes in DL use HARQ-ACK bundling for Cat M1 HD-FDD UEs, scheduling is performed as follows:

[0057] For HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 0, the HARQ-ACK delay value is set to:

[0058] 11 BL / CE DL subframes + 1 absolute subframe for DL / UL switching subframe + 1 BL / CE UL subframe;

[0059] For HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 1, the HARQ-ACK delay value is set to:

[0060] 11 BL / CE DL subframes + 1 absolute subframe for DL / UL switching subframe) + (1*Rpucch+1) BL / CE UL subframes; and

[0061] For HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 2, the HARQ-ACK delay value is set to:

[0062] 11 BL / CE DL subframes + 1 absolute subframe for DL / UL switching subframe) + (2*Rpucch+1) BL / CE UL subframes,

[0063] where HARQ#n represents the HARQ process with the largest HARQ-ACK delay, Rpucch represents the number of PUCCH repetitions, and the delay count for the HARQ-ACK delay value starts after the last subframe in which the PDSCH is transmitted.

[0064] In this embodiment, preferably, in the case where there are PUCCH repetitions, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps, in the case where 14 HARQ processes in the DL use HARQ-ACK bundling for Cat Ml HD-FDD UEs, the scheduling is performed as follows:

[0065] For average HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 0, the HARQ-ACK delay value is set to:

[0066] ceil(11 / (1-x%) BL / CE DL subframes not overlapping with measurement gaps + 1 absolute subframe for DL / UL switching subframe, unless it overlaps with measurement gaps + 1 / (1-y%) BL / CE UL subframes not overlapping with measurement gaps + {0, no measurement gap; 6 or 7, measurement gap} absolute subframes);

[0067] For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 1, the HARQ-ACK delay value is set to:

[0068] ceil(11 / (1-x%) of BL / CE DL subframes not overlapping with measurement gap + 1 of absolute subframes for DL / UL switching subframes, unless it overlaps with measurement gap + (1*Rpucch+1) / (1-y%) of BL / CE UL subframes not overlapping with measurement gap + {0, no measurement gap; 6 or 7, with measurement gap} absolute subframes);

[0069] For the average HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 2, the HARQ-ACK delay value is set to:

[0070] ceil(11 / (1-x%) of BL / CE DL subframes not overlapping with measurement gap + 1 of absolute subframes for DL / UL switching subframes, unless it overlaps with measurement gap + (2*Rpucch+1) / (1-y%) of BL / CE UL subframes not overlapping with measurement gap + {0, no measurement gap; 6 or 7, with measurement gap} absolute subframes,

[0071] where x% represents the fraction of invalid BL / CE DL subframes relative to BL / CE DL subframes not overlapping with measurement gap, y% represents the fraction of invalid BL / CE UL subframes relative to BL / CE DL subframes not overlapping with measurement gap, Rpucch represents the number of PUCCH repetitions.

[0072] In this embodiment, preferably, in case of 14 HARQ processes in DL using HARQ-ACK bundling for Cat Ml HD-FDD UEs in the absence of PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gap, the procedure specified in 3GPP TS 36.213 is scheduled to be performed, the entirety of 3GPP TS 36.213 being incorporated herein by reference.

[0073] In this embodiment, preferably, the definition of BL / CE DL subframes and BL / CE UL subframes remains the same as the legacy definition, while the definition of absolute subframes refers to any type of subframes.

[0074] In this embodiment, preferably, invalid BL / CE DL subframes are used to perform DL to UL switching or UL to DL switching, or to make transmission in UL.

[0075] In this embodiment, preferably, the invalid BL / CE UL subframe is used for performing DL to UL switching or UL to DL switching, or transmitting in the DL.

[0076] Figure 4 is a block diagram illustrating an apparatus for scheduling a delay associated with a HARQ process in LTE-MTC according to another embodiment.

[0077] Reference is made to Figure 4 , the apparatus 40 comprises a storage device 410 and a processor 420 coupled to the storage device 410. The storage device 410 is configured to store a computer program 430 comprising computer instructions. The processor 420 is configured to execute the computer instructions to perform some or all of the method steps as shown in Figure 3 .

[0078] Figure 5 is a flowchart illustrating a method 500 for scheduling a delay associated with a HARQ process in LTE-MTC according to another embodiment of the present application.

[0079] As shown in Figure 5 , the flowchart comprises the following steps performed at the UE side:

[0080] Step 501 : receiving a HARQ-ACK delay value.

[0081] Step 502: transmitting a PUCCH subframe for HARQ-ACK or HARQ-NACK with the HARQ-ACK delay value.

[0082] In this embodiment, the HARQ-ACK delay value is scheduled according to a HARQ-ACK scheduling count policy determined in response to the presence or absence of PUCCH repetition, invalid BL / CE DL subframe, invalid BL / CE UL subframe, and measurement gap.

[0083] In this embodiment, preferably, the HARQ-ACK delay value is included in a DCI from a NodeB.

[0084] In this embodiment, preferably, the HARQ-ACK delay value is represented as one of a plurality of multi-bit values stored in a HARQ-ACK delay table.

[0085] Figure 6 is a block diagram illustrating an apparatus for scheduling a delay associated with a HARQ process in LTE-MTC according to another embodiment.

[0086] Reference is made to Figure 6The apparatus 60 includes a storage device 610 and a processor 620 coupled to the storage device 610. The storage device 610 is configured to store a computer program 630 including computer instructions. The processor 620 is configured to execute the computer instructions to perform some or all of the method steps as shown in Figure 5

[0087] The Rel-17 objective of introducing “N-HARQ processes in DL for HD-FDD Cat M1 UEs” does not consider the further delays caused when this feature happens to coexist with PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps, which will impact the HARQ-ACK delay. In this disclosure, methods to support the introduction of “N-HARQ processes in DL for HD-FDD Cat M1 UEs” in the presence of PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps are described. For the purpose of illustration and to be consistent with the Rel-17 WID, 14 HARQ processes are used as the basis to describe these methods, but they can be applied to N HARQ processes.

[0088] Throughout this disclosure, the term “invalid BL / CE DL subframe” used herein can correspond to the term “non-BL / CE DL subframe” in 3GPP technical specifications.

[0089] In general, in the presence of MG, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and PUCCH repetition, the available HARQ-ACK delay values are insufficient, so the number of HARQ processes that can be used will be limited. The following examples illustrate that even with 10 HARQ processes in DL using HARQ-ACK bundling, the available set of HARQ-ACK delay values is not sufficient to handle the required HARQ-ACK delays.

[0090] Example 1: Reference Figure 7 The “downlink subframe bitmap 1110011110 is described, which marks invalid BL / CE DL subframes with ‘0’.”

[0091] In Example 1, not all 10 HARQ processes can be scheduled because there are no available HARQ-ACK delay values for HARQ processes 0, 1, and 2. That is, in Figure 7 , only the delay values highlighted with the “diagonal dashed line” pattern are available in the HARQ-ACK delay set of “ce-HARQ-AckBundling” (see Table 1).

[0092] Example 2: Reference Figure 8 ​The description “Measurement gap. Measurement gap duration and its periodicity are defined by a variable measurement gap length (MGL) and measurement gap repetition period (MGRP) as defined in 3GPP specification TS 36.133.”

[0093] +1 subframe because it is assumed that Cat-M1 UEs cannot transmit anything in UL in the subframe after this measurement gap. In Example 2, not all 10 HARQ processes can be scheduled because HARQ processes 0, 1, 2, 3, 4, 5 do not have available HARQ-ACK delays.

[0094] Example 3: Reference Figure 9 The description “This example illustrates the presence of PUCCH repetition for the case of number of PUCCH repetitions = 8.”

[0095] In Example 3, not all 10 HARQ processes can be scheduled because there are not enough available HARQ-ACK delay values. It is known that PUCCH 0, 1, 2 can each handle up to 4 HARQ processes, respectively. Therefore, in Example 3:

[0096] • Any combination of 4 HARQ processes from 0 to 7 can be bundled using PUCCH 0 (e.g., HARQ processes 0, 1, 2, and 3 use all PUCCH 0 to send ACK / NACK).

[0097] Or

[0098] • Up to 6 HARQ processes can be handled by bundling 4 HARQ processes from 0 to 7 using PUCCH 0, and 2 HARQ processes 8 and 9 using PUCCH 1.

[0099] In Rel-17, the introduction of “14 HARQ processes in DL using HARQ-ACK bundling for Cat M1 HD-FDD UEs” will require additional HARQ-ACK delay values, and will limit the number of more HARQ processes that can be used.

[0100] As mentioned above, for 14 HARQ processes, up to 12 HARQ processes can be handled by a given HARQ-ACK bundle set that includes 3 PUCCHs. While there are a total of 14 HARQ processes, the increase in peak data rate is estimated using 12 HARQ processes because 2 of the 14 processes need to cross UL transmissions (see Figure 2). The term "cross-UL transmission" is used to describe the case of DL data scheduling for a specific DL HARQ process, where the UL (PUCCH) transmission occurs between the MPDCCH carrying the DL grant and the associated PDSCH carrying the DL data. The 14 HARQ processes using HARQ-ACK bundling is introduced in the presence of PUCCH repetition, invalid BL / CE DL subframes, and invalid BL / CE UL subframes.

[0101] In one embodiment introducing "14 HARQ processes in DL using HARQ-ACK bundling for Cat Ml HD-FDD UEs", the HARQ-ACK delay is handled according to the following HARQ-ACK scheduling counting policy in the presence of invalid BL / CE DL subframes, invalid BL / CE UL subframes, and PUCCH repetition (i.e. the number of PUCCH repetitions, denoted as "Rpucch"):

[0102] Assuming the HARQ process with the maximum HARQ-ACK delay is HARQ#n and the delay count starts after the last subframe in which the PDSCH is transmitted, then

[0103] • The HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 0 is 11 BL / CE DL subframes + 1 absolute subframe (i.e. for DL / UL switching subframe) + 1 BL / CE UL subframe

[0104] • The HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 1 is 11 BL / CE DL subframes + 1 absolute subframe (i.e. for DL / UL switching subframe)

[0105] + (1*Rpucch+1) BL / CE UL subframes

[0106] • The HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 2 is 11 BL / CE DL subframes + 1 absolute subframe (i.e. for DL / UL switching subframe)

[0107] + (2*Rpucch+1) BL / CE UL subframes

[0108] In one embodiment, the symbol "+" means "after" to illustrate the order of calculating the delay.

[0109] In one embodiment, the definition of BL / CE DL subframe and BL / CE UL subframe remains the same as the conventional definition, while the definition of absolute subframe refers to any type of subframe.

[0110] In one embodiment, invalid BL / CE DL subframes are assumed to be available for performing DL to UL switching, UL to DL switching, or transmitting in UL (e.g., PUCCH).

[0111] In one embodiment, invalid BL / CE UL subframes are assumed to be available for performing DL to UL switching, UL to DL switching, or transmitting in DL (e.g., MPDCCH, or PDSCH).

[0112] Introduce 14 HARQ processes using HARQ-ACK bundling in the presence of PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps.

[0113] In one embodiment, the presence of measurement gaps is incorporated into the HARQ-ACK scheduling counting strategy in the following way:

[0114] Assuming a fraction of x% of invalid BL / CE DL subframes, a fraction of y% of invalid BL / CE UL subframes, and a measurement gap length of 6 or 7:

[0115] The equations under the following three sub-bullets describe the average HARQ-ACK delay from the farthest HARQ process (described below as “HARQ#n”) that can be bundled into PUCCH0, 1, or 2, respectively. The HARQ-ACK delay starts from the subframe after the end of PDSCH until the subframe used to transmit PUCCH0, 1, or 2. The following equations include the presence of invalid subframes and measurement gaps in percentage. The absence of invalid subframes or measurement gaps can serve as a starting point to understand the following equations, as this case results in average HARQ-ACK delays from the farthest HARQ process to PUCCH0, 1, and 2 equal to 13, 14, and 15, respectively, which is similar to the case where the farthest HARQ process is “HARQ#12” (see also the upper part of Table 2, corresponding to the columns of 0% for x and y). Figure 2 .

[0116] • The average HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 0 is ceil(11 / (1-x%) BL / CE DL subframes not overlapping with measurement gaps + 1 absolute subframe (i.e., for DL / UL switching subframes), unless it overlaps with measurement gaps + 1 / (1-y%) BL / CE UL subframes not overlapping with measurement gaps + {0, no MG; 6 or 7, with MG} absolute subframes)

[0117] • The HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 1 is ceil(11 / (1-x%) BL / CE DL subframes not overlapping with measurement gap + 1 absolute subframe (i.e. DL / UL switching subframe) unless it overlaps with measurement gap + (1*Rpucch+1) / (1-y%) BL / CE UL subframes not overlapping with measurement gap + {0, no MG; 6 or 7, with MG} absolute subframes)

[0118]

[0119] • The average HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 2 is ceil(11 / (1-x%) BL / CE DL subframes not overlapping with measurement gap + 1 absolute subframe (i.e. DL / UL switching subframe) unless it overlaps with measurement gap + (2*Rpucch+1) / (1-y%) BL / CE UL subframes not overlapping with measurement gap + {0, no MG; 6 or 7, with MG} absolute subframes).

[0120] In one embodiment, the symbol "+" means "subsequently" to illustrate the order of calculating the delay.

[0121] In one embodiment, the definitions of BL / CE DL subframe, BL / CE UL subframe and measurement gap remain the same as the legacy definitions, while the definition of absolute subframe refers to any type of subframe.

[0122] In one embodiment, it is assumed that invalid BL / CE DL subframes can be used to perform DL to UL switching, UL to DL switching or transmission in UL (e.g. PUCCH).

[0123] In one embodiment, it is assumed that invalid BL / CE UL subframes can be used to perform DL to UL switching, UL to DL switching or transmission in DL (e.g. MPDCCH, or PDSCH).

[0124] Table 2 shows several cases of invalid BL / CE DL subframes, invalid BL / CE UL subframes, PUCCH repetition existing with different percentages and their impact on HARQ-ACK delay.

[0125] Table 2: Invalid BL / CE DL subframes, invalid BL / CE UL subframes, PUCCH repetition existing with different percentages and their impact on HARQ-ACK delay.

[0126]

[0127]

[0128] ​For the example in Table 2, if PDSCH scheduling encounters an MG, the HARQ-ACK delay for HARQ#n is increased by 6 or 7 subframes.

[0129] In one embodiment introducing “14 HARQ processes in DL use HARQ-ACK bundling for Cat M1 HD-FDD UE in DL”, the HARQ-ACK delay value set is increased from 8 to 16 by increasing the “HARQ-ACK delay” field size by 1 bit (i.e., using 4 bits instead of 3 bits) in DCI format 6-1A, which makes the HARQ-ACK scheduling count policy compatible with the HARQ-ACK delay value set in 3GPP specification TS 36.213 “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Layer Procedures” (Release 16.2.0). Alternatively, a new 4-bit field is introduced for DCI format 6-1A to provide HARQ-ACK delay when “14 HARQ processes in DL use HARQ-ACK bundling for Cat M1 HD-FDD UE in DL” is configured.

[0130] In one embodiment, the “HARQ-ACK delay for BL / CE UE in CE Mode A” is updated similar to Table 3 below to handle the HARQ delay when PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps are present when “14 HARQ processes in DL use HARQ-ACK bundling for Cat M1 HD-FDD UE in DL” is configured.

[0131] Table 3: “HARQ-ACK delay for BL / CE UE in CE Mode A”, including support for “14 HARQ processes in DL use HARQ-ACK bundling for Cat M1 HD-FDD UE in DL”.

[0132]

[0133]

[0134] In Table 3, the maximum step size in ‘HARQ-ACK delay’ is 3 (e.g., from 15 to 18). With HARQ-ACK bundling, the channel condition is basically good, so only a small number of PUCCH repetitions, e.g., 1 2, or even 4 repetitions, need to be covered in most cases. When MG is used for RSTD, the MGL is usually large, which results in a large HARQ-ACK delay, so only a small MGL, e.g., MGL = 6, needs to be covered.

[0135] In a dependent embodiment, when the configuration "14 HARQ processes in DL use HARQ-ACK bundling for Cat M1 HD-FDD UE in DL" is configured and the "HARQ-ACK delay" field uses 4 bits:

[0136] • 8 out of the 16 combinations provided by the 4 bits of the "HARQ-ACK delay" field correspond to the set of HARQ-ACK delay values available in legacy (i.e. 4, 5, 6, 7, 8, 9, 10, and 11) to provide backward compatibility.

[0137] • 2 out of the 16 combinations provided by the 4 bits of the "HARQ-ACK delay" field correspond to the additional HARQ-ACK delay values needed when the "14 HARQ processes in DL use HARQ-ACK bundling for Cat M1 HD-FDD UE in DL" is configured and used in its most basic form without considering the presence of PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps (i.e. 13 and 15).

[0138] • 6 out of the 16 combinations provided by the 4 bits of the "HARQ-ACK delay" field correspond to additional HARQ-ACK delay values for handling scenarios when the "14 HARQ processes in DL use HARQ-ACK bundling for Cat M1 HD-FDD UE in DL" is configured and subject to the presence of PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps, either individually or simultaneously.

[0139] • The set of HARQ-ACK delay values for handling the presence of PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps, either individually or simultaneously, can be any integer values (e.g. obtained from statistics, simulations, etc.) and is not limited to the set of values in Table 3 for illustration purposes.

[0140] • This set of HARQ-ACK delay values does not cover all possible scenarios that can arise due to the presence of PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps, either individually or simultaneously, but is intended to evaluate the most common scenarios envisioned for practical deployments.

[0141] Some examples are shown in Figures 10-12 for illustration of the use of the HARQ-ACK scheduling count policy of Table 3 when the "14 HARQ processes in DL use HARQ-ACK bundling for Cat M1 HD-FDD UE in DL" is configured.

[0142] Example 4: Referring to Figure 10Description "When 14 HARQ processes in the DL use HARQ-ACK bundling for Cat M1 HD-FDD UEs" is subject to the presence of invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps.

[0143] The delay values highlighted with the "diagonal dashed line" pattern are available in the HARQ-ACK delay set of Table 3.

[0144] In Example 4, with the 'HARQ-ACK Delay' based on Table 3, not all 12 HARQ processes can be used, as HARQ processes #12, #0, #1, #3, #5, and #7 can only use HARQ-ACK bundling 1 (recall that the number of PDSCH transmissions bundled in one HARQ-ACK cannot exceed 4). Thus, in this example, with the new 'HARQ-ACK Delay' table, the maximum number of HARQ processes that can be scheduled is 11 instead of 12.

[0145] Example 5: Reference Figure 11 Description "The scenario is the same as in Example 4, except that the measurement gap is moved to the right subframe, resulting in different HARQ-ACK delay requirements".

[0146] The delay values highlighted with the "diagonal dashed line" pattern are available in the HARQ-ACK delay set of Table 3.

[0147] In Example 5, with the 'HARQ-ACK Delay' based on Table 3, all 12 HARQ processes can be scheduled simultaneously.

[0148] Example 6: Reference Figure 12 Description "This example represents a scenario where there is no measurement gap, which results in different HARQ-ACK delay requirements".

[0149] The delay values highlighted with the "diagonal dashed line" pattern are available in the HARQ-ACK delay set of Table 3.

[0150] In Example 6, with the 'HARQ-ACK Delay' based on Table 3, even without the MG, not all 12 HARQ processes can be used (note that for HARQ processes #12 and #4, there is no available HARQ-ACK delay). Thus, as previously mentioned, the HARQ-ACK delay value set in Table 3 does not cover all possible scenarios that can arise from the presence of PUCCH repetition, invalid BL / CE DL subframes, invalid BL / CE UL subframes, and measurement gaps, either individually or simultaneously, as the HARQ-ACK delay set should consider the most common scenarios that can be foreseen in a real deployment.

[0151] In one embodiment, the HARQ-ACK delay count policy for supporting 14 HARQ processes in DL may be described as a set of rules or any other form / format other than a table format (eg, Table 3).

[0152] It should be noted that the foregoing embodiments are illustrative rather than restrictive, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. Phrases such as "comprises" and "comprising" do not exclude elements or steps that are present but not listed in the specification and claims. It should also be noted that as used herein and in the appended claims, the singular forms "a", "an" and "the" include plural objects unless the context clearly dictates otherwise. The embodiments may be implemented by hardware comprising a plurality of different elements or by a suitably programmed computer. In a unit claim that lists several means, several of these means may be embodied in the same hardware item. The use of the words first, second, third, etc. does not imply any order and may simply be interpreted as names.

Claims

1. A method for HARQ-ACK delay associated with a HARQ process in LTE-MTC performed by a UE (60), the method comprising: Receiving (501) downlink control information, the downlink control information indicating a HARQ-ACK delay value associated with a HARQ process in LTE-MTC; as well as sending (502) a physical uplink control channel PUCCH, said PUCCH comprising a HARQ-ACK or HARQ-NACK with a delay according to said HARQ-ACK delay value, wherein the HARQ-ACK delay value is scheduled according to a HARQ-ACK scheduling count policy; the HARQ-ACK scheduling count policy is determined in response to the presence or absence of PUCCH repetitions, invalid BL / CE downlink DL subframes, invalid BL / CE uplink UL subframes, and measurement gaps; Among them, in the case of 14 HARQ processes in DL using HARQ-ACK bundling for Category M1 HD-FDD UE: For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 0, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + 1 BL / CE UL subframe; For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 1, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + (1*Rpucch+1) BL / CE UL subframes; and For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 2, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + (2*Rpucch+1) BL / CE UL subframes, Here, HARQ#n represents the HARQ process with the maximum HARQ-ACK delay, Rpucch represents the number of PUCCH repetitions, and the delay counting of the HARQ-ACK delay value starts after the last subframe in which the PDSCH is sent.

2. The method of claim 1 , wherein the HARQ-ACK delay value is represented as one of a plurality of multi-bit values ​​in a HARQ-ACK delay table.

3. A UE (60) for HARQ-ACK delay associated with a HARQ process in LTE-MTC, the UE comprising: a storage device (610) configured to store a computer program (630) comprising computer instructions; as well as a processor (620) coupled to the memory device and configured to execute the computer instructions to: receiving downlink control information indicating a HARQ-ACK delay value associated with a HARQ process in LTE-MTC; and transmitting a physical uplink control channel (PUCCH), the PUCCH including a HARQ-ACK or a HARQ-NACK delayed according to the HARQ-ACK delay value, wherein the HARQ-ACK delay value is scheduled according to a HARQ-ACK scheduling count policy; the HARQ-ACK scheduling count policy is determined in response to the presence or absence of PUCCH repetitions, invalid BL / CE downlink DL subframes, invalid BL / CE uplink UL subframes, and measurement gaps; Among them, in the case of 14 HARQ processes in DL using HARQ-ACK bundling for Category M1 HD-FDD UE: For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 0, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + 1 BL / CE UL subframe; For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 1, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + (1*Rpucch+1) BL / CE UL subframes; and For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 2, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + (2*Rpucch+1) BL / CE UL subframes, Here, HARQ#n represents the HARQ process with the maximum HARQ-ACK delay, Rpucch represents the number of PUCCH repetitions, and the delay counting of the HARQ-ACK delay value starts after the last subframe in which the PDSCH is sent.

4. The UE of claim 3, wherein the HARQ-ACK delay value is represented as one of a plurality of multi-bit values ​​in a HARQ-ACK delay table.

5. A method for HARQ-ACK delay associated with a HARQ process in LTE-MTC, the method comprising: sending downlink control information to a UE (60), the downlink control information indicating a HARQ-ACK delay value, receiving a physical uplink control channel (PUCCH), the PUCCH including a HARQ-ACK or a HARQ-NACK with a delay according to the HARQ-ACK delay value, wherein the HARQ-ACK delay value is scheduled according to a HARQ-ACK scheduling count policy; the HARQ-ACK scheduling count policy is determined in response to the presence or absence of PUCCH repetitions, invalid BL / CE downlink DL subframes, invalid BL / CE uplink UL subframes, and measurement gaps; Among them, in the case of 14 HARQ processes in DL using HARQ-ACK bundling for Category M1 HD-FDD UE: For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 0, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + 1 BL / CE UL subframe; For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 1, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + (1*Rpucch+1) BL / CE UL subframes; and For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 2, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + (2*Rpucch+1) BL / CE UL subframes, Here, HARQ#n represents the HARQ process with the maximum HARQ-ACK delay, Rpucch represents the number of PUCCH repetitions, and the delay counting of the HARQ-ACK delay value starts after the last subframe in which the PDSCH is sent.

6. The method of claim 5, wherein the HARQ-ACK delay value is represented as one of a plurality of multi-bit values ​​in a HARQ-ACK delay table.

7. The method according to claim 5, wherein: Determining the HARQ-ACK scheduling counting strategy includes the steps of: selecting one of multiple candidate HARQ-ACK delay counting strategies as the HARQ-ACK scheduling counting strategy based on the presence or absence of PUCCH repetition, invalid BL / CE DL subframes, invalid BL-CE UL subframes and measurement gaps.

8. An apparatus (40) for detecting HARQ-ACK delay associated with a HARQ process in LTE-MTC, the apparatus comprising: a storage device (410) configured to store a computer program (430) comprising computer instructions; and a processor (420) coupled to the memory device and configured to execute the computer instructions to: sending downlink control information indicating a HARQ-ACK delay value to a UE (60), receiving a physical uplink control channel PUCCH containing a HARQ-ACK or HARQ-NACK with a delay according to the HARQ-ACK delay value, wherein the HARQ-ACK delay value is scheduled according to a HARQ-ACK scheduling count policy; the HARQ-ACK scheduling count policy is determined in response to the presence or absence of PUCCH repetitions, invalid BL / CE downlink DL subframes, invalid BL / CE uplink UL subframes, and measurement gaps; Among them, in the case of 14 HARQ processes in DL using HARQ-ACK bundling for Category M1 HD-FDD UE: For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 0, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + 1 BL / CE UL subframe; For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 1, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + (1*Rpucch+1) BL / CE UL subframes; and For the HARQ-ACK delay between HARQ#n and HARQ-ACK bundle 2, the HARQ-ACK delay value is: 11 BL / CE DL subframes + 1 subframe + (2*Rpucch+1) BL / CE UL subframes, Here, HARQ#n represents the HARQ process with the maximum HARQ-ACK delay, Rpucch represents the number of PUCCH repetitions, and the delay counting of the HARQ-ACK delay value starts after the last subframe in which the PDSCH is sent.

9. The device according to claim 8, wherein The HARQ-ACK delay value is represented as one of a plurality of multi-bit values ​​in a HARQ-ACK delay table.

10. A computer program product embodied in a computer-readable storage medium and comprising computer instructions which, when executed by a computing device, cause the computing device to perform the method according to any one of claims 1-2 or 5-7.

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