IEEE C802.16m-09/2666
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Proposed Changes in 16m/D2 Related to DL Feedback in Multicarrier Systems
(15.2.8)
Date
Submitted
2009-11-17
Source(s)
Lei Wang
Voice : +1 858 205-7286
InterDigital Communications, LLC
E-mail: leiw@billeigean.com
Re:
IEEE 802.16 Working Group Letter Ballot #30a on P802.16m/D2
Abstract
The contribution proposes the changes in 16m/D2 regarding the DL feedback in
multicarrier systems.
Purpose
To be discussed and adopted by TGm for the 802.16m DRAFT amendment.
Notice
Release
Patent
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Proposed Changes in 802.16m/D2 Related to Feedback
Channel for DL-only Carriers in Multicarrier Systems (15.2.8)
Lei Wang
InterDigital Communications, LLC
1 Introduction
The comment #508 in the comment database 80216-09_0047.cmt for the IEEE 802.16 Working
Group Letter Ballot #30 on P802.16m/D1 identified an issue related to the DL feedback of the
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IEEE C802.16m-09/2666
secondary carriers, particularly, DL-only carriers, in multicarrier systems. During the comment
resolution discussion in the Jeju meeting, the Multicarrier (MC) ad hoc group suggested, after a
quite long discussion about the issue, that although the identified issue needs to be resolved, they
“reject” to the comment #508, under the consideration that the suggested remedy is incomplete.
This contribution proposes the changes in 802.16m/D2 to further address the DL feedback issue in
multicarrier systems as identified by comment #508 in 80216-09_0047.cmt.
2 Discussions
As indicated by the paragraph in line 8 on page 152 in the 802.16m/D2, there are two basic ways
for the AMS to provide the DL feedback of the active secondary carriers in multicarrier systems:
one is PHY fast feedback channel, and the other is MAC messages. However, the current
802.16m/D2 does not have any details regarding how the AMS provides DL feedback in either
PHY feedback channel or MAC messages. Moreover, in the feedback channel allocation section,
15.3.6.5.2.11, on page 391, the first paragraph explicitly excludes the case of more than one
feedback channel allocated to an AMS.
Based on the discussion in Jeju, we believe it is important for the AMS to provide DL feedback
for the active DL secondary carriers, including the unpaired active DL secondary carriers. The
unpaired active DL carrier refers to the active DL carrier that does not have corresponding active
UL carrier, e.g., partially configured carriers, DL-only activated carrier, etc.
In the 802.16m/D2, the feedback channels can be used for both HARQ ACK/NAK and Fast
feedback. To provide feedback channels for the DL-only active carriers in multicarrier systems,
we propose the following:
1)
The feedback channels for the DL-only active carriers shall be allocated on the primary UL
carrier;
2)
For each DL-only active carrier, one feedback region shall be allocated on the primary UL
carrier, which contains the feedback channels for the fast feedback and the HARQ
ACK/NAK channels of the DL-only active carrier; i.e., for a multicarrier system with
DL-only active carriers, there will be multiple feedback regions allocated on the primary
UL carrier, one for the primary DL carrier and one for each DL-only active carriers;
3)
The mapping between the DL carriers and the feedback regions on the primary UL carrier is
pre-defined, such that the current feedback channel allocation and HARQ ARQ/NAK
allocation mechanisms can stay unchanged.
3 Suggested changes in the 802.16m/D2
Based on the above discussion, we propose the following changes in the 802.16m/D2. Note that
the new text is marked with blue and underline; the deleted text are marked with red and
strikethrough.
Suggested change #1: page 152, line 8
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IEEE C802.16m-09/2666
Change the paragraph in line 8 on page 152 as follows:
An ABS may assign fast feedback CQI channels to each carrier of an AMS. When fast feedback CQI channel is
assigned, the AMS reports CINR for a carrier over the assigned fast feedback CQI channel of the corresponding
carrier. ABS may also direct AMS to report CINRs of active carriers through fast feedback CQI channel(s) on the
primary carrier at the feedback region as defined in Section 15.3.8.3.3. When measurement/report MAC messages
are used for DL CINR report operation, the messages are transmitted on the AMS's primary carrier. The
measurement/report MAC message may contain CINR reports for all carriers or for each carrier of the AMS.
Suggested change #2: page 391 line 52
Change the text from line 52 on page 391 to line 18 on page 392 as follows:
Table 818 describes the fields in a Feedback Allocation A-MAP IE used for dynamically allocating or de-allocating UL fast
feedback control channels (including both PFBCH and SFBCH) to an AMS. If an AMS has an existing fast feedback
control channel for an active DL carrier and receives a new feedback channel allocation for the same active DL carrier,
the original fast feedback channel is de-allocated automatically.
Definitions of the fields in the Feedback Allocation A-MAP IE are listed below in Table 818.
Suggested change #3: page 459 line 29
Change the paragraph in line 29 on page 459 as follows:
The distributed LRUs in each of uplink frequency partition may be further divided into data, bandwidth request, and
feedback regions channels. The A feedback region consists of feedback channels can be used for both HARQ ACK/NAK
and fast feedback. In a multicarrier system with active DL-only carriers, the primary UL carrier should contain
multiple feedback regions for the primary DL carrier and the active DL-only carriers. The primary UL carrier should
contain one feedback region corresponding to each DL carrier with a pre-defined mapping. The allocation order of
data channels and UL control channels are TBD.
4 References
[1] IEEE Std 802.16-2009
[2] IEEE P802.16m/D2, “DRAFT Amendment to IEEE Standard for Local and metropolitan area
networks”
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