HK1157964A

HK1157964A - Uplink transmission time interval bundling with measurement gaps

Info

Publication number: HK1157964A
Application number: HK11111988.8A
Authority: HK
Inventors: 张国栋; 王津
Original assignee: Interdigital Patent Holdings, Inc.
Priority date: 2008-07-10
Filing date: 2009-07-08
Publication date: 2012-07-06

Description

Uplink transmission time interval bundling with measurement gaps

Technical Field

The present application relates to wireless communications.

Background

In third generation partnership project (3GPP) Long Term Evolution (LTE) wireless communication systems, Transmission Time Interval (TTI) bundling is used in Uplink (UL) communications to improve coverage for wireless transmit/receive units (WTRUs) near the edge of a cell. For LTE Frequency Division Duplex (FDD) systems, hybrid automatic repeat request (HARQ) processes and Redundancy Versions (RVs) associated with the HARQ processes are bundled and transmitted in a fixed number (e.g., 4) of consecutive TTIs.

Fig. 1 shows uplink TTI bundling 100 according to the prior art. The HARQ RTT time 102 is the minimum number of subframes before the WTRU expects a Downlink (DL) HARQ retransmission. As shown in fig. 1, data 110 is transmitted in sub-frame 1(102), sub-frame 2(104), sub-frame 3(106), and sub-frame 4 (108). A negative acknowledgement signal (NACK)112 for subframe 4(108) is received by the WTRU in subframe 8 (114). The WTRU then retransmits subframe 4(108) in 4 subframes (116 to 122) after the RTT time 102, which subframe 4(108) is the subframe that is negatively acknowledged.

When the WTRU is in connected mode, it uses measurement gaps to stop active communication and makes measurements on neighboring cells for possible handover. The measurement gaps are scheduled by an enodeb (enb). The eNB may schedule measurement gaps regardless of the likelihood that the WTRU may need to retransmit a subframe as part of a HARQ process. Thus, the eNB may schedule the measurement gap of the WTRU while the WTRU is retransmitting due to the NACK. If this happens, the TTI bundling may overlap with the measurement gap (overlap) and requires the WTRU to perform two mutually exclusive procedures. Figure 2 shows that measurement gaps overlap TTI bundles 200 according to the prior art. The measurement gap 202 overlaps with subframe 1(204) of the TTI 206. Since the WTRU cannot perform HARQ retransmissions and measurements simultaneously, only a portion of the TTI bundle 206 may be transmitted.

Disclosure of Invention

A method and apparatus for a Wireless Transmit Receive Unit (WTRU) to transmit a Transmission Time Interval (TTI) bundling that conflicts with a measurement gap is disclosed. The WTRU may construct a TTI bundle including a plurality of subframes, determine that at least one subframe conflicts with a measurement gap, and determine that at least one subframe does not conflict with a measurement gap. The WTRU may then associate the first non-colliding subframe with a first Redundancy Version (RV), associate the second non-colliding subframe with a second RV if the second non-colliding subframe is available, and associate the third non-colliding subframe with a third RV if the third non-colliding subframe is available. Non-colliding subframes are transmitted, while colliding subframes are not transmitted.

Drawings

The invention will be understood in more detail from the following description, given by way of example and understood in conjunction with the accompanying drawings, in which:

FIG. 1 shows a method for uplink TTI bundling according to the prior art;

figure 2 shows that measurement gaps overlap TTI bundling according to prior art;

figure 3 shows a wireless communication system including a plurality of WTRUs and an enodeb (enb);

figure 4 is a functional block diagram of a WTRU and an eNB of the wireless communication system of figure 3;

FIG. 5 illustrates TTI bundling in accordance with an embodiment;

FIG. 6 shows a method for transmitting TTI bindings having first overlapping subframes in accordance with an embodiment;

FIG. 7 shows a method for transmitting TTI bindings with last overlapping subframes in accordance with an embodiment;

FIG. 8 shows a method for transmitting TTI bindings with an overlap of the first two sub-frames, according to an embodiment;

FIG. 9 shows a method for transmitting TTI bindings with an overlap of the last two sub-frames, in accordance with an embodiment;

FIG. 10 shows a method for transmitting TTI bindings with an overlap of the first three subframes, according to an embodiment; and

fig. 11 shows a method for transmitting TTI bundling with a last three subframe overlap according to an embodiment.

Detailed Description

The term "wireless transmit/receive unit (WTRU)" as referred to below includes, but is not limited to, a User Equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a Personal Digital Assistant (PDA), a computer, or any other type of user equipment capable of operating in a wireless environment. The term "base station" as referred to below includes, but is not limited to, a node B, an evolved node B, a site controller, an Access Point (AP), or any other type of interfacing device capable of operating in a wireless environment.

Figure 3 shows a wireless communication system 300 including a plurality of WTRUs 310 and an enodeb (enb) 320. As shown in fig. 3, the WTRU 310 communicates with the eNB. Although three WTRUs 310 and one eNB 320 are shown in figure 3, it should be noted that any combination of wireless and wired devices may be included in the wireless communication system 300.

Figure 4 is a functional block diagram of a WTRU 310 and an eNB 320 in the wireless communication system 300 of figure 3. As shown in fig. 3, the WTRU 310 communicates with the eNB 320. The WTRU 310 is configured to perform the required measurements. If the WTRU 310 is in connected mode, the WTRU 310 is configured to perform a measurement routine (routine) during the measurement gap. The WTRU 310 is also configured to transmit signals that are grouped into subframes in a TTI binding.

In addition to the components that may be found in a typical WTRU, the WTRU 310 includes a processor 415, a receiver 416, a transmitter 417, and an antenna 418. The WTRU 310 may also include a user interface 421 including, but not limited to, an LCD or LED screen, a touch screen, a keyboard, a stylus, or any other typical input/output device. The WTRU 310 may also include volatile and non-volatile memory 419 and interfaces 420 to other WTRUs, such as USB ports, serial ports, and the like. The receiver 416 and the transmitter 417 are in communication with the processor 415. The antenna 418 is in communication with both the receiver 416 and the transmitter 417 to facilitate the transmission and reception of wireless data.

In addition to the components that may be found in a typical eNB, eNB 320 includes a processor 425, a receiver 426, a transmitter 427, and an antenna 428. The receiver 426 and the transmitter 427 are in communication with the processor 425. The antenna 428 is in communication with both the receiver 426 and the transmitter 427 to facilitate the transmission and reception of wireless data.

Figure 5 shows TTI bundling 500 according to an embodiment. In one TTI bundling 500 transmission, the same data is transmitted on 4 consecutive subframes using different Redundancy Versions (RVs) or associated with different RVs.

The RV specifies the starting point of the circular buffer to start reading bits. Different RVs are specified by defining different starting points for initiating HARQ operations. RV0 may be selected for the first transmission because this allows as many systematic bits as possible to be transmitted. Different RVs may be selected for retransmission of the same packet supporting various types of HARQ combining. Several RV sequences may be used for TTI bundling. For example, the sequences RV0, RV2, RV3 and RV1 can be used. As another example, the sequences RV0, RV1, RV2 and RV3 may be used. Generally any sequence starting at RV0 can be used because RV0 includes most systematic bits. RV used herein_i(where i ═ 1, 2, 3, or 4) is an index, and may refer to any RV. For example, RV₁May be referred to as (refer to) RV 3.

Returning to FIG. 5, the first subframe 502 includes a reference frame with the RV₀Associated data. RV (direction of rotation)₀Including most systematic bits. The second subframe 504 includes a second subframe with the RV₁Associated data. The third subframe 506 includes a common reference frame (RV)₂Associated data, and the fourth subframe 508 includes data associated with the RV₃Associated data. When at least a portion of the TTI bundling 500 overlaps with a measurement gap, the portion of the TTI bundling 500 that overlaps with the measurement gap will not be transmitted. Non-overlapping portions of the TTI bundling 500 will be transmitted.

When one subframe overlaps with a measurement gap, the RV sequence { RV₀，rv₁，rv₂Can be used for each of the cells that are not overlapped by the measurement gapOne sub-frame. The RV sequence may be used when the first subframe is overlapped or the last subframe is overlapped. Figure 6 shows a method for transmitting a TTI bundling 600 with first overlapping subframes, according to an embodiment. The measurement gap 602 overlaps the first sub-frame 604. Thus, the first overlapping sub-frame 604 is not transmitted. The second subframe 606 is the first transmitted subframe and includes the RV₀Associated data. A third subframe 608 and a fourth subframe 610 are also transmitted and include the RV, respectively₁And RV₂Associated data.

Figure 7 shows a method for transmitting a TTI bundle 600 with last overlapping subframes according to an embodiment. In fig. 7, the measurement gap 702 overlaps with the fourth subframe 704 of the TTI bundle. Thus, the fourth subframe 704 of the TTI bundle is not transmitted. The first subframe 706 of TTI bundling comprises a reference frame with the RV₀Associated data, a second subframe 708 of the TTI bundle includes an RV₁Associated data, and a third subframe 710 of the TTI bundle includes an RV₂Associated data. A first subframe 706, a second subframe 708, and a third subframe 710 are transmitted.

Two of the four subframes in a TTI binding may overlap with a measurement gap. Figure 8 shows a diagram for transmitting a TTI bundle 600 with an overlap of the first two subframes, according to an embodiment. The measurement gap 802 overlaps with 2 subframes (i.e., a first subframe 804 and a second subframe 806). The first sub-frame 804 and the second sub-frame 806 are not transmitted. The third subframe 808 comprises the same RV as the RV₀Associated data and is transmitted first. The fourth sub-frame 810 includes a TV and a sub-frame₁The associated data and the second is sent. RV sequence { RV₀，rv₁Is used for TTIs not affected by measurement gaps.

Fig. 9 shows a method for transmitting a TTI bundle 600 with a last two subframe overlap according to an embodiment. The measurement gap 902 overlaps with 2 subframes (i.e., the last subframe 904 and the second to last subframe 906). The last sub-frame 904 and the second last sub-frame 906 are not transmitted. The first subframe 908 comprises a first subframe and a RV₀Associated data and is transmitted first. The second sub-frame 910 includes a sub-frame associated with TV₁The associated data and the second is sent. RV sequence { RV₀，rv₁Which is in turn used for TTIs not affected by measurement detection. Alternatively, the RV sequence { RV when two subframes overlap with a measurement gap can be used₂，rv₃}。

If 3 subframes overlap with the measurement gap, RV may be selected for subframes not affected by the measurement gap₀. Fig. 10 shows a method for transmitting a TTI bundle 600 with an overlap of the first three subframes according to an embodiment. The measurement gap 1002 overlaps with 3 subframes (i.e., the first subframe 1004, the second subframe 1006, and the third subframe 1008). These subframes are not transmitted. The last subframe 1010 includes the RV₀Associated data and the last subframe 1010 is transmitted. RV sequence { RV₀Is used for TTIs not affected by measurement gaps.

Fig. 11 shows a method for transmitting a TTI bundle 600 with a last three subframe overlap according to an embodiment. The measurement gap 1102 overlaps with 3 subframes (i.e., the second subframe 1106, the third subframe 1108, and the fourth subframe 1110). These subframes are not transmitted. The first subframe 1104 includes a reference frame (RV)₀Associated data and the first subframe 1104 is transmitted. RV sequence { RV₀Is used for TTIs not affected by measurement gaps.

Alternatively, TTI bundling transmissions may be cancelled when a portion of the TTI bundling overlaps with the measurement gap. A TTI bundled transmission may be cancelled if any k subframes overlap the measurement gap, where k is an integer between 1 and 4.

Examples

1. A method for a Wireless Transmit Receive Unit (WTRU) to transmit a Transmission Time Interval (TTI) bundle, wherein a portion of the TTI bundle conflicts with a measurement gap, the method comprising: constructing a TTI bundle comprising a plurality of subframes; determining that at least one subframe of the plurality of subframes is in conflict with a measurement gap; determining a first subframe of the plurality of subframes that does not collide with the measurement gap; associating a first subframe of the plurality of subframes that does not collide with the measurement gap with a first Redundancy Version (RV); and transmitting a first subframe of the plurality of subframes associated with the first RV.

2. The method of embodiment 1, further comprising: determining a second subframe of the plurality of subframes that does not collide with the measurement gap; associating a second subframe of the plurality of subframes that does not collide with the measurement gap with a second RV; transmitting a second subframe of the plurality of subframes associated with the second RV.

3. The method of embodiment 2, further comprising transmitting a second subframe of the plurality of subframes after a first subframe of the plurality of subframes.

4. The method as in any one of embodiments 1, 2 or 3 further comprising preventing transmission of at least one of the plurality of subframes that collides with the measurement gap.

5. The method as in any one of embodiments 1-4, further comprising: determining that the first two subframes are in conflict with the measurement gap; block transmission of the first two subframes; associating a third subframe with the first RV and a fourth subframe with a second RV; and transmitting the third subframe and the fourth subframe.

6. The method as in any one of embodiments 1-4, further comprising: determining that the first three subframes conflict with the measurement gap; block transmission of the first three subframes; associating a fourth subframe with the first RV; and transmitting the fourth subframe.

7. The method as in any one of embodiments 1-4, further comprising: determining that the last two subframes are in conflict with the measurement gap; and blocking transmission of the last two subframes.

8. The method as in any one of embodiments 1-4, further comprising: determining that the last three subframes conflict with the measurement gap; and blocking transmission of the last three subframes.

9. A method for a Wireless Transmit Receive Unit (WTRU) to transmit a Transmission Time Interval (TTI) bundle, wherein a portion of the TTI bundle conflicts with a measurement gap, the method comprising: constructing a TTI bundle comprising a plurality of subframes; determining that at least one subframe of the plurality of subframes is in conflict with a measurement gap; determining a first subframe of the plurality of subframes that does not collide with the measurement gap; associating a first subframe of the plurality of subframes that does not collide with the measurement gap with a first Redundancy Version (RV); determining a second subframe of the plurality of subframes that does not collide with the measurement gap; associating a second subframe of the plurality of subframes that does not collide with the measurement gap with a second RV; transmitting a first subframe of the plurality of subframes associated with the first RV and a second subframe of the plurality of subframes associated with the second RV; preventing transmission of at least one of the plurality of subframes that collides with the measurement gap.

10. A Wireless Transmit Receive Unit (WTRU) configured to transmit a Transmission Time Interval (TTI) bundle, wherein a portion of the TTI bundle conflicts with a measurement gap, comprising: a processor configured to: constructing a TTI bundle comprising a plurality of subframes; determining that at least one subframe of the plurality of subframes is in conflict with a measurement gap; determining a first subframe of the plurality of subframes that does not collide with the measurement gap; and associating a first subframe of the plurality of subframes that does not collide with the measurement gap with a first Redundancy Version (RV); and a transmitter configured to transmit a first subframe of the plurality of subframes associated with the first RV.

11. The WTRU of embodiment 10, wherein: the processor is further configured to: determining a second subframe of the plurality of subframes that does not collide with the measurement gap; and associating a second subframe of the plurality of subframes that does not collide with the measurement gap with a second RV; and the transmitter is further configured to transmit a second subframe of the plurality of subframes associated with the second RV.

12. The WTRU of embodiment 11 wherein the transmitter is further configured to transmit a second subframe of the plurality of subframes after a first subframe of the plurality of subframes.

13. The WTRU of embodiment 12, wherein the processor is further configured to prevent transmission of at least one of the plurality of subframes that conflicts with the measurement gap.

14. The WTRU as in any one of embodiments 10-13 wherein the processor is further configured to: determining that the first two subframes are in conflict with the measurement gap; block transmission of the first two subframes; and associating a third subframe with the first RV and a fourth subframe with a second RV; and the transmitter is further configured to transmit the third subframe and the fourth subframe.

15. The WTRU as in any one of embodiments 10-13 wherein the processor is further configured to: determining that the first three subframes conflict with the measurement gap; block transmission of the first three subframes; and associating a fourth subframe with the first RV; and the transmitter is further configured to transmit the fourth subframe.

16. The WTRU as in any one of embodiments 10-13 wherein the processor is further configured to: determining that the last two subframes are in conflict with the measurement gap; and blocking transmission of the last two subframes.

17. The WTRU of embodiment 10, wherein the processor is configured to: determining that the last three subframes conflict with the measurement gap; and blocking transmission of the last three subframes.

18. A Wireless Transmit Receive Unit (WTRU) configured to transmit a Transmission Time Interval (TTI) bundle, wherein a portion of the TTI bundle conflicts with a measurement gap, the WTRU comprising: a processor configured to: constructing a TTI bundle comprising a plurality of subframes; determining that at least one subframe of the plurality of subframes is in conflict with a measurement gap; determining a first subframe of the plurality of subframes that does not collide with the measurement gap; associating a first subframe of the plurality of subframes that does not collide with the measurement gap with a first Redundancy Version (RV); determining a second subframe of the plurality of subframes that does not collide with the measurement gap; associating a second subframe of the plurality of subframes that does not collide with the measurement gap with a second RV; and preventing transmission of at least one of the plurality of subframes that conflicts with the measurement gap; and a transmitter configured to transmit a first subframe of the plurality of subframes associated with the first RV and a second subframe of the plurality of subframes associated with the second RV.

Although the features and elements of the present invention are described above in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the present invention.

While this invention has been described in terms of preferred embodiments, other variations within the scope of this invention will be apparent to those skilled in the art.

Although the features and elements of the present invention are described above in particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements of the present invention. The methods or flow charts provided in the present invention may be implemented in a computer program, software, or firmware tangibly embodied in a computer-readable storage medium, examples of which include Read Only Memory (ROM), Random Access Memory (RAM), registers, buffer memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and Digital Versatile Disks (DVDs), for execution by a general purpose computer or a processor.

For example, suitable processors include: a general-purpose processor, a special-purpose processor, a conventional processor, a Digital Signal Processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, any other type of Integrated Circuit (IC), and/or a state machine.

A processor in association with software may be used to implement a radio frequency transceiver for use in a Wireless Transmit Receive Unit (WTRU), User Equipment (UE), terminal, base station, Radio Network Controller (RNC), or any host computer. The WTRU may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, bluetoothA module, a Frequency Modulation (FM) radio unit, a Liquid Crystal Display (LCD) display unit, an Organic Light Emitting Diode (OLED) display unit, a digital music player, a media player, a video game player module, an internet browser, and/or any of a Wireless Local Area Network (WLAN) module or a wireless Ultra Wide Band (UWB) module.

Claims

1. A method for a Wireless Transmit Receive Unit (WTRU) to transmit a Transmission Time Interval (TTI) bundle, wherein a portion of the TTI bundle conflicts with a measurement gap, the method comprising:

constructing a TTI bundle comprising a plurality of subframes;

determining that at least one subframe of the plurality of subframes is in conflict with a measurement gap;

determining a first subframe of the plurality of subframes that does not collide with the measurement gap;

associating the first subframe of the plurality of subframes that does not collide with the measurement gap with a first Redundancy Version (RV); and

transmitting the first subframe of the plurality of subframes associated with the first RV.

2. The method of claim 1, further comprising:

determining a second subframe of the plurality of subframes that does not collide with the measurement gap;

associating the second subframe of the plurality of subframes that does not collide with the measurement gap with a second RV;

transmitting the second subframe of the plurality of subframes associated with the second RV.

3. The method of claim 2, further comprising transmitting the second one of the plurality of subframes after the first one of the plurality of subframes.

4. The method of claim 1, further comprising preventing transmission of at least one of the plurality of subframes that collides with the measurement gap.

5. The method of claim 1, further comprising:

determining that the first two subframes are in conflict with the measurement gap;

block transmission of the first two subframes;

associating a third subframe with the first redundancy version and a fourth subframe with a second redundancy version; and

transmitting the third subframe and the fourth subframe.

6. The method of claim 1, further comprising:

determining that the first three subframes conflict with the measurement gap;

block transmission of the first three subframes;

associating a fourth subframe with the first redundancy version; and

transmitting the fourth subframe.

7. The method of claim 1, further comprising:

determining that the last two subframes are in conflict with the measurement gap; and

blocking transmission of the last two subframes.

8. The method of claim 1, further comprising:

determining that the last three subframes conflict with the measurement gap; and

blocking transmission of the last three subframes.

9. A method for a Wireless Transmit Receive Unit (WTRU) to transmit a Transmission Time Interval (TTI) bundle, wherein a portion of the TTI bundle conflicts with a measurement gap, the method comprising:

constructing a TTI bundle comprising a plurality of subframes;

associating the first subframe of the plurality of subframes that does not collide with the measurement gap with a first Redundancy Version (RV);

transmitting the first subframe of the plurality of subframes associated with the first RV and the second subframe of the plurality of subframes associated with the second RV;

preventing transmission of at least one of the plurality of subframes that collides with the measurement gap.

10. A Wireless Transmit Receive Unit (WTRU) configured to transmit a Transmission Time Interval (TTI) bundle, wherein a portion of the TTI bundle conflicts with a measurement gap, comprising:

a processor configured to:

constructing a TTI bundle comprising a plurality of subframes;

determining a first subframe of the plurality of subframes that does not collide with the measurement gap; and

a transmitter configured to transmit the first subframe of the plurality of subframes associated with the first RV.

11. The WTRU of claim 10, wherein:

the processor is further configured to:

determining a second subframe of the plurality of subframes that does not collide with the measurement gap; and

associating the second subframe of the plurality of subframes that does not collide with the measurement gap with a second RV; and is

The transmitter is further configured to transmit the second subframe of the plurality of subframes associated with the second RV.

12. The WTRU of claim 11, wherein the transmitter is further configured to transmit the second one of the plurality of subframes after the first one of the plurality of subframes.

13. The WTRU of claim 11, wherein the processor is further configured to prevent transmission of at least one of the plurality of subframes that conflicts with the measurement gap.

14. The WTRU of claim 10, wherein:

the processor is further configured to:

block transmission of the first two subframes; and

associating a third subframe with the first redundancy version and a fourth subframe with a second redundancy version; and is

The transmitter is further configured to transmit the third subframe and the fourth subframe.

15. The WTRU of claim 10, wherein:

the processor is further configured to:

determining that the first three subframes conflict with the measurement gap;

block transmission of the first three subframes; and

associating a fourth subframe with the first redundancy version; and is

The transmitter is further configured to transmit the fourth subframe.

16. The WTRU of claim 10, wherein the processor is further configured to:

blocking transmission of the last two subframes.

17. The WTRU of claim 10, wherein the processor is configured to:

blocking transmission of the last three subframes.

18. A Wireless Transmit Receive Unit (WTRU) configured to transmit a Transmission Time Interval (TTI) bundle, wherein a portion of the TTI bundle conflicts with a measurement gap, the WTRU comprising:

a processor configured to:

constructing a TTI bundle comprising a plurality of subframes;

associating a second subframe of the plurality of subframes that does not collide with the measurement gap with a second RV; and

preventing transmission of at least one of the plurality of subframes that conflicts with the measurement gap; and

a transmitter configured to transmit the first subframe of the plurality of subframes associated with the first RV and the second subframe of the plurality of subframes associated with the second RV.