Transcript Slides S802.16j-08/099r1

A more efficient DL-MAP IE for MAPs
Document Number:
IEEE S802.16m-08/099r1
Date Submitted:
2008-05-14
Source:
Kanchei (Ken) Loa, Tsung-Yu Tsai, Yi-Hsueh Tsai, Yung-Ting Lee, Hua-Chiang Yin
Voice:
E-mail:
+886-2-6600-0100
[email protected]
Institute for Information Industry (III)
7F, No. 133, Sec. 4, Minsheng E. Rd., Taipei City 105, Taiwan
Re:
IEEE 802.16j-08/020: “IEEE 802.16 Working Group Letter Ballot Recirc #28c: Announcement”
Abstract:
This contribution proposes the compressed DL-MAP IE
Purpose:
Text proposal for 802.16j Draft Document.
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A More Efficient DL-MAP IE for
MAPs
Institute of Information Industry (III)
Introduction
• Four parameters are included in the DL-MAP IE to describe a
2D allocation
– “OFDMA symbol offset”, “OFDMA sub-channel offset”, “number of
OFDMA symbols”, and “number of OFDMA sub-channels”
• The above approach is intuitive but not efficient since the
MAP overhead is high
• This contribution proposes a Compressed DL-MAP IE
– Only two parameters: “number of OFDMA symbols” and “number of
subchannels” are used to describe the 2D allocation
– The receiver can uniquely re-construct the 2D allocations
• The Compressed DL-MAP IE replace the original DL-MAP IE
in RS_Access-MAP, RS_Relay-MAP, and R-MAP to reduce
the MAP overheads on the relay link
– Reduce the DL-MAP IE overhead of DL data burst description from 27
bits to 13 bits
Concept of Compressed DL-MAP IE (1)
• Specifically, we index the DL zone as a 2-D time-frequency
(OFDMA symbols-subchannels) table
– Every slots of the DL zone are indexed (1 ~ 38) as shown in right-hand
side of the below figure
• The index of the left top slot of a burst is the “start index” of
that burst
– In the figure below, the start indices of the data bursts, shown in left
hand side of the following figure, are 6, 7, 9, 21, 26, and 35,
respectively
1
7
13
19
26
33
2
8
14
20
28
34
3
9
15
21
29
35
4
10
16
22
30
36
5
11
17
23
31
37
6
12
18
24
32
38
FCH
DL-MAP
Concept of Compressed DL-MAP IE (2)
• The data burst are further indexed as Burst 1, Burst 2, and so on, sorted in a
increasing order as shown in the below figure
• With the burst sequence and given the corresponding “length” (number of
OFDMA symbols) and “width” (number of subchannels) of every burst, the
2D allocations of the DL zone can be re-constructed uniquely
– The allocations of FCH and MAPs are known already
– The start index of the first burst can be uniquely identified. Moreover, the
allocation of the first burst can be identified by the given “length” and “width”
– Similarly, knowing the allocations of FCH, DL-MAP, and the first burst, the start
index of the second burst can be uniquely identified
L2
W2
DL-MAP
L5
W5
Burst 2
L3
L4
Burst 3
Burst 4
7
13
19
26
33
2
8
14
20
28
34
3
9
15
21
29
35
4
10
16
22
30
36
5
11
17
23
31
37
6
12
18
24
32
38
Burst 5
L6
W3
W4
1
W6
Burst 6
L1
W1
Burst 1
Example 1: Full Allocation
Every slot is allocated
L2
W2
DL-MAP
L5
W5
Burst 2
L3
L4
Burst 3
Burst 4
7
13
19
26
33
2
8
14
20
28
34
3
9
15
21
29
35
4
10
16
22
30
36
5
11
17
23
31
37
6
12
18
24
32
38
Burst 5
L6
W3
W4
1
W6
Burst 6
L1
W1
DL-MAP IE 1
CID 1
(L1, W1)
Burst 1
DL-MAP IE 2
CID 2
(L2, W2)
DL-MAP IE 3
CID 3
(L3, W3)
DL-MAP IE 4
CID 4
(L4, W4)
DL-MAP IE 5
CID 5
(L5, W5)
DL-MAP IE 6
CID 6
(L6, W6)
Example 2: Partial Allocation
Not all slots are allocated
• Since the DL data burst is rectangular, we can use one or
more “null rectangular bursts” for those slots which are not
allocated
L2
W2
DL-MAP
W3
L5
W5
Burst 2
L3
L4
No
Allocation
Burst 4
W4
1
7
13
19
26
33
2
8
14
20
28
34
3
9
15
21
29
35
4
10
16
22
30
36
5
11
17
23
31
37
6
12
18
24
32
38
Burst 5
L6
W6
Burst 6
L1
W1
DL-MAP IE 1
CID 1
(L1, W1)
Burst 1
DL-MAP IE 2
CID 2
(L2, W2)
DL-MAP IE 3
Null CID 3
(L3, W3)
DL-MAP IE 4
CID 4
(L4, W4)
DL-MAP IE 5
CID 5
(L5, W5)
DL-MAP IE 6
CID 6
(L6, W6)
Null Burst
Proposed Compressed DL-MAP IE
RS_Access-MAP with Proposed
Compressed DL-MAP IE
R-MAP with Proposed Compressed DLMAP IE
Conclusions
• In this contribution, a Compressed DL-MAP IE is
proposed to reduce the overheads of R-MAP,
RS_Access-MAP, and RS_Relay-MAP
• The complexity is
,
where N , S, and C are the number of IEs, the number
of symbols, and the number of subchannels,
respectively
• Adopt the proposed text changes in C80216j-08/099r1
or later version