Proposed Text for the IEEE 802.16M Amendment on HARQ Timing

Proposed Text for the IEEE 802.16M Amendment on HARQ Timing

IEEE C802.16m-09/0286

Project / IEEE 802.16 Broadband Wireless Access Working Group <>
Title / Proposed Text for the IEEE 802.16m Amendment on HARQ Timing
Date Submitted / 2009-01-07
Source(s) / Yujian Zhang, Hujun Yin, Yuan Zhu
Intel Corporation
/ +86-10-82611515
{yujian.zhang,hujun.yin,yuan.y.zhu}@intel.com
*<
Re: / “802.16m amendment working document”:
IEEE 802.16m-08/053r1, “Call for Contributions on Project 802.16m Draft Amendment Content”.
Target topic: “Channel Coding and HARQ”.
Abstract / Proposed text for HARQ timing in the draft P802.16m amendment
Purpose / Discussion and adoption by TGm
Notice / This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein.
Release / The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.16.
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Proposed Text for the IEEE 802.16m Amendment on HARQ Timing

Yujian Zhang, Hujun Yin, Yuan Zhu

Intel Corporation

  1. Introduction

The contribution proposes the text on HARQ timing for 802.16m amendment. The proposed text is developed so that it can be readily combined with IEEE P802.16 Rev2/D7 [1], it is compliant to the 802.16m SRD [2] and the 802.16m SDD [3], and it follows the style and format guidelines in [4].

  1. Modifications to the SDD text

The text proposed in this contribution is based on subclause 11.13.2 in the IEEE 802.16m SDD [3]. The modifications to the SDD text are summarized below:

  • Add notations for HARQ timing calculation
  • Define DL HARQ timing for both FDD and TDD
  • Define UL HARQ timing for both FDD and TDD
  1. References

[1] IEEE P802.16 Rev2/D8, “Draft IEEE Standard for Local and Metropolitan Area Networks: Air Interface
for Broadband Wireless Access,” Dec. 2008.

[2] IEEE 802.16m-07/002r6, “802.16m System Requirements”

[3] IEEE 802.16m-08/003r6, “The Draft IEEE 802.16m System Description Document”

[4] IEEE 802.16m-08/043, “Style guide for writing the IEEE 802.16m amendment”

15.3.8 Channel coding and HARQ

15.3.8.1 Channel coding for traffic

15.3.8.2 Channel coding for USCCH

15.3.8.3 HARQ

15.3.8.3.1 HARQ type
15.3.8.3.2 Bit re-arrangement
15.3.8.3.3 DL HARQ buffer management
15.3.8.3.4 Adaptive HARQ
15.3.8.3.5 HARQ feedback
15.3.8.3.6 HARQ timing

Throughout this section, frames are numbered in ascending order. If the last frame of a superframe is denoted as frame, then the first frame of the next superframe is denoted as frame.

Within each frame, subframes are numbered in ascending order with index starting from 0. Subframe indexis numbered continuously within the frame, irrespective whether the subframe is in DL or UL, or whether it belongs to legacy 802.16e zone or not. For example, for 8-subframe-frame, denotes the first subframe while denotes the last subframe.

Notations used in this section:

 Pair: starting subframe position of data burst (re)transmission.

 Pair : subframe position for ACKCH associated with data burst (re)transmission .

 Pair : starting subframe position of data burst retransmission associated with data burst (re)transmission .

 Pair: subframe position of USCCH scheduling data burst (re)transmission.

 : total number of subframes per frame.

 : TTI length of data burst (re)transmission in terms of number of subframes.

 : Rx processing time in terms of number of subframes. .

 :Tx processing time in terms of number of subframes. .

 : USCCH transmission frequency. .

Various factors like legacy 802.16e zones and relay zones make some subframes not available for 802.16m transmissions. Defining HARQ timing for all these combinations is impractical, therefore generalized frame structures for FDD and TDD are provided below for HARQ timing specification.

Generalized Frame Structure for FDD

Figure xxx below illustrates the frame structure used for FDD HARQ timing. DL zone consists of subframes, while UL zone consists of subframes. There are possibly 2 idle regions with length of, subframes for DL and length of, subframes for UL. Each of, , , could be 0.

Figure xxx. Frame structure for FDD HARQ Timing Control

Following relationships should be satisfied.

Generalized Frame Structure for TDD

Figure yyy below illustrates the frame structure used for TDD HARQ timing. DL zone consists of subframes, while UL zone consists of subframes. There are possibly 3 idle regions with length of,, and subframes. Each of,, and could be 0.

Figure yyy. Frame structure for TDD HARQ Timing Control

Following relationship should be satisfied.

Note that in the generalized frame structures above, idle region means that there are no associated transmissions. Detailed definitions are given in DL and UL sections separately.

15.3.8.3.6.1 HARQ Timing in the Downlink

IEEE 802.16m uses asynchronous HARQ scheme in the downlink.

FDD DL HARQ

For FDD DL HARQ, DL zone in Figure xxx includes subframes that are used for IEEE 802.16m DL data burst transmissions. All other subframes within the frame are categorized as DL idle regions.

For FDD DL HARQ, UL zone in Figure xxx includes subframes that are used for IEEE 802.16m UL ACKCH transmissions. All other subframes within the frame are categorized as UL idle regions.

The following timing relationship shall be applied.

 When, DL data burst transmission corresponding to a DL Assignment IE or a MIMO DL Assignment IE in sub-frame shall begin in sub-frame, i.e. . When, there is one bit in DL Assignment IE or a MIMO DL Assignment IE in sub-frame , and the corresponding DL data burst transmission shall begin in sub-frame , i.e. . Note that when is odd and, should be only.

 ACKCH is transmitted in subframe , where

TDD DL HARQ

For TDD DL HARQ, DL zone in Figure yyy includes subframes that are used for IEEE 802.16m DL data burst transmissions, while UL zone in Figure yyy includes subframes that are used for IEEE 802.16m UL ACKCH transmissions. Note that both DL zone and UL zone are associated with same kind of transmissions, e.g. BS to MS transmission in DL, or BS to RS transmission in DL. All other subframes within the frame are categorized as idle regions.

The following timing relationship shall be applied.

 When, DL data burst transmission corresponding to a DL Assignment IE or a MIMO DL Assignment IE in sub-frame shall begin in sub-frame, i.e. . When, there is one bit in DL Assignment IE or a MIMO DL Assignment IE in sub-frame , and the corresponding DL data burst transmission shall begin in sub-frame , i.e. . Note that when is odd and, should be only.

 ACKCH is transmitted in subframe , where

15.3.8.3.6.2 HARQ Timing in the Uplink

IEEE 802.16m uses synchronous HARQ scheme in the uplink.

FDD UL HARQ

For FDD UL HARQ, DL zone in Figure xxx includes subframes that are used for IEEE 802.16m DL ACKCH transmissions. All other subframes within the frame are categorized as DL idle regions.

For FDD UL HARQ, UL zone in Figure xxx includes subframes that are used for IEEE 802.16m UL data burst transmissions. All other subframes within the frame are categorized as UL regions.

The following timing relationship shall be applied.

 There is one parameter to indicate the timing relationship between USCCH and associated UL data. Details are FFS.

 ACKCH is transmitted in subframe , where

 Starting subframe position of data burst retransmission is located in subframe , where

TDD UL HARQ

For TDD UL HARQ, DL zone in Figure yyy includes subframes that are used for IEEE 802.16m DL ACKCH transmissions, while UL zone in Figure yyy includes subframes that are used for IEEE 802.16m UL data burst transmissions. Note that both DL zone and UL zone are associated with same kind of transmissions, e.g. MS to BS transmission in DL, or RS to BS transmission in DL. All other subframes within the frame are categorized as idle regions.

The following timing relationship shall be applied.

 There is one parameter to indicate the timing relationship between USCCH and associated UL data. Details are FFS.

 ACKCH is transmitted in subframe , where

 Starting subframe position of data burst retransmission is located in subframe , where