IEEE C802.16m-09/0510r2
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Proposed Text of Channel Coding and HARQ for the IEEE 802.16m Amendment
Date
Submitted
2009-03-11
Source(s)
Jerry Pi
Samsung Electronics Co., Ltd.
+1-972-761-7944
zpi@sta.samsung.com
The Channel Coding and HARQ Drafting
Group Editor
Re:
802.16m AWD
Abstract
The contribution proposes the text of channel coding and HARQ section to be included in the
802.16m amendment.
Purpose
To be discussed and adopted by TGm for the 802.16m amendment.
Notice
Release
Patent
Policy
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.
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.
The contributor is familiar with the IEEE-SA Patent Policy and Procedures:
<http://standards.ieee.org/guides/bylaws/sect6-7.html#6> and
<http://standards.ieee.org/guides/opman/sect6.html#6.3>.
Further information is located at <http://standards.ieee.org/board/pat/pat-material.html> and
<http://standards.ieee.org/board/pat>.
1
IEEE C802.16m-09/0510r2
Proposed Text of Channel Coding and HARQ
for the IEEE 802.16m Amendment
Jerry Pi
Samsung Electronics Co., Ltd.
The Channel Coding and HARQ Drafting Group Editor
1. Introduction
The contribution proposes the text of channel coding and HARQ section to be included in the 802.16m
amendment ([1]). The proposed text is developed so that it can be readily combined with IEEE P802.16
Rev2/D8 ([2]), it is compliant to the 802.16m SRD ([3]) and the 802.16m SDD ([4]), and it follows the style
and format guidelines in ([5]).
2. References
[1] IEEE 802.16m-09/0010, “802.16m Amendment Working Document (AWD)”
[2] IEEE P802.16 Rev2/D8, “Draft IEEE Standard for Local and Metropolitan Area Networks: Air Interface
for Broadband Wireless Access,” Dec. 2008.
[3] IEEE 802.16m-07/002r7, “IEEE 802.16m System Requirements Document”
[4] IEEE 802.16m-08/003r6, “IEEE 802.16m System Description Document”
[5] IEEE 802.16m-08/043, “Style guide for writing the IEEE 802.16m amendment”
2
IEEE C802.16m-09/0510r2
3. Text proposal for inclusion in the 802.16m amendment
-------------------------------
Text Start
---------------------------------------------------
4. Abbreviations and acronyms
Insert the following at section 4 in alphabetic order:
CoRe
HARQ
IR
MCS
SPID
constellation re-arrangement
hybrid-ARQ
incremental redundancy
Modulation and Coding Scheme
subpacket ID
Insert the following subsection at a new section 15:
15.x. Channel coding and HARQ
15.x.1.
Channel coding
Channel coding procedures for downlink and uplink data channel are shown in Figure 15.x.1-1.
Burst
CRC
encoder
Data
Randomizer
Burst
partition
FEC
block
CRC
encoder
FEC
encoder
Bit selection
&
Repetition
Collection
Modulation
Figure 15.x.1-1. Channel coding procedure
15.x.1.1.
Burst CRC encoding
Cyclic Redundancy Code (CRC) bits are used to detect errors in the received packets. A 16-bit burst CRC is appended to
the data burst with the following cyclic generator polynomial:
g DB-CRC ( D)  D16  D12  D 5  1
Denote the bits of the input data burst by d1 , d 2 , d 3 , , d N PL with d1 being the MSB and NPL being the size of the
input data burst. Denote the parity bits produced by the burst CRC generator by p1, p2 , p3 , , p16 . The burst CRC
encoding is performed in a systematic form, which means that in GF(2), the polynomial:
d1 D N PL 15  d 2 D N PL 14    d n D16  p1 D15  p2 D14    p15 D1  p16
yields a remainder equal to 0 when divided by
g DB-CRC ( D) .
The data burst, including the CRC, is further processed by the data randomizer as described in section 15.x.1.2.
3
IEEE C802.16m-09/0510r2
15.x.1.2.
Randomization
Data randomization shall be performed on the downlink and uplink data channel.
The randomization bits are generated using a PRBS generator as shown in Figure 15.x.1-2. The generator polynomial of
the PRBS generator is 1  X 14  X 15 . For each data burst, the beginning state of the PRBS is initialized to [s1 s2 … s15] =
[0 1 1 0 1 1 1 0 0 0 1 0 1 0 1] with s1 being the LSB and s15 being the MSB. The data burst to be transmitted shall enter
sequentially into the randomizer, MSB first. The data bits are XOR-ed with the output of the PRBS generator, with the
MSB of the data burst XOR-ed with the first bit of the PRBS generator output.
LSB
MSB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
data out
data in
Figure 15.x.1-2.The data randomizer with a PRBS generator
The output of the data randomizer is further processed by burst partition as described in section 15.x.1.3.
15.x.1.3.
Burst partition
When the burst size including 16 burst CRC bits exceeds the maximum FEC block size, NFB_MAX, the burst is partitioned
into KFB FEC blocks. The modulation order, the nominal code rate, the number of resource elements allocated for data
transmission, the spatial multiplexing order, and the maximum FEC block size are denoted by Nmod, RFEC, NRE, NSM,
NFB_MAX, respectively.
Nmod
RFEC
NRE
NSM
NFB_MAX
is the modulation order of the burst transmission, which is specified by MCS index
is the nominal code rate of the burst transmission, which is specified by MCS index
is the number of resource elements allocated for burst transmission. The calculation of NRE shall exclude
the resource elements used by pilot channels
is the spatial multiplexing order of the resource elements allocated for burst transmission. The value of NSM
depends on the MIMO transmission mode and is defined in section x.x.x.x.
is the maximum FEC block size, which equals to 4800 bits.
The nominal MCS used in a data transmission shall be selected from Table 15.x.1-1.
Table 15.x.1-1. MCS table for downlink and uplink data channel
MCS index
Modulation
Code rate
‘0000’
QPSK
31/256
‘0001’
QPSK
48/256
‘0010’
QPSK
71/256
‘0011’
QPSK
101/256
‘0100’
QPSK
135/256
4
IEEE C802.16m-09/0510r2
‘0101’
QPSK
171/256
‘0110’
16QAM
102/256
‘0111’
16QAM
128/256
‘1000’
16QAM
155/256
‘1001’
16QAM
184/256
‘1010’
64QAM
135/256
‘1011’
64QAM
157/256
‘1100’
64QAM
181/256
‘1101’
64QAM
205/256
‘1110’
64QAM
225/256
‘1111’
64QAM
237/256
The size of the k-th FEC block is denoted by NFB, k, k = 0, 1, …, KFB-1. The set of supported FEC block sizes is shown in
Table 15.x.1-2.
Table 15.x.1-2. FEC block size table for downlink and uplink data channels
Index
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
NFB
48
64
72
80
88
96
104
120
128
136
144
152
160
176
184
192
200
208
216
232
240
248
256
264
272
288
296
304
312
320
Index
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
NFB
328
344
352
360
368
376
384
400
416
432
440
456
472
480
496
512
528
544
552
568
584
600
608
624
640
656
664
680
696
712
Index
NFB
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
720
736
752
768
776
800
824
848
872
888
912
936
960
984
1000
1024
1048
1072
1096
1112
1136
1160
1184
1216
1248
1280
1312
1336
1368
1392
5
Index
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
NFB
1424
1448
1480
1504
1536
1560
1600
1640
1672
1712
1752
1784
1824
1864
1896
1920
1952
2000
2048
2096
2144
2192
2232
2280
2328
2368
2432
2496
2560
2624
Index
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
NFB
2752
2816
2880
2944
3008
3072
3200
3264
3328
3392
3456
3520
3648
3712
3776
3840
3904
3968
4096
4160
4224
4288
4352
4416
4544
4608
4672
4736
4800
IEEE C802.16m-09/0510r2
The burst size NDB including burst CRC and FEC block CRC is defined by the following equation:
N DB 
K FB 1
N
k 0
FB, k
.
The payload size excluding burst CRC and FEC block CRC is defined by the following equation:
N PL  N DB  N DBCRC  I MFB  K FB  N FBCRC
where,
IMFB
NFB-CRC
NDB-CRC
equals 0 when KFB =1, 1 when KFB >1,
equals 16, which is the size of FEC block CRC,
equals 16, which is the size of burst CRC.
The burst partition block generates KFB FEC blocks, with each FEC block processed by the FEC block CRC encoding
block as described in 15.x.1.4.
15.x.1.4.
FEC block CRC encoding
The burst partition procedure generates KFB FEC blocks for each burst. If KFB > 1, the FEC block CRC generator appends
a 16-bit FEC block CRC for each FEC block. The cyclic generator for FEC block CRC encoding is shown as follows:
g FBCRC ( D)  D16  D15  D 2  1.
Denote the bits of the k-th input FEC block by
d1 , d 2 , d3 , , d NFB, k 16 with d1 being the MSB and NFB, k being the
size of the k-th input FEC block, including the 16-bit FEC block CRC. Denote the parity bits produced by the burst CRC
generator by p1, p2 , p3 , , p16 . The burst CRC encoding is performed in a systematic form, which means that in GF(2),
the polynomial:
d1 D
N FB,k 1
 d2 D
N FB,k  2
   d NFB,k 16 D16  p1 D15  p2 D14    p15 D1  p16
yields a remainder equal to 0 when divided by
15.x.1.5.
g FB-CRC ( D) .
FEC encoding
Each FEC block shall be encoded using the convolutional turbo codes specified in section 15.x.1.5.1.
15.x.1.5.1.
Convolutional turbo codes (CTCs)
15.x.1.5.1.1. CTC encoder
The CTC encoder, including its constituent encoder, is depicted in Figure 15.x.1-2.
It uses a double binary CRSC (Circular Recursive Systematic Convolutional) code.
6
IEEE C802.16m-09/0510r2
The bits of the data to be encoded are alternatively fed to A and B, starting with the MSB of the first byte being fed to A,
followed by the next bit being fed to B. The encoder is fed by blocks of NEP bits ( N FB  2 N bits).
The polynomials defining the connections are described in octal and symbol notations as follows:
- For the feedback branch: 15, equivalently 1  D  D3 (in symbolic notation)
- For the Y parity bit: 13, equivalently 1  D2  D3
- For the W parity bit: 11, equivalently 1  D3
output
A
A
B
B
1
CTC
Interleaver
Constituent
Encoder
2
C1
Y1W1
C2
Y2W2
switch
Systematic part
A
S1
S2
S3
B
Parity part
Y
W
Figure 15.x.1-2. CTC encoder
First, the encoder (after initialization by the circulation state S C2 , see 15.13.1.6.1.3Error! Reference source not found.)
is fed the sequence in the natural order (switch 1 in Figure ) with incremental address i  1,2,, N . This first encoding is
called C1 encoding.
Then the encoder (after initialization by the circulation state S C2 , see 15.13.1.6.1.3) is fed by the interleaved sequence
(switch 2 in Figure ) with incremental address i  1,2,, N . This second encoding is called C2 encoding.
The order in which the encoded bits shall be fed into the bit separation block (15.x.1.6.1.4) is:
A, B, Y1 , Y2 , W1 ,W2 
A0 , A1 ,, AN 1 , B0 , B1 , , BN 1 , Y1,0 , Y1,1 ,, Y1, N 1 , Y2,0 , Y2,1 ,, Y2, N 1 ,W1,0 ,W1,1 ,,W1, N 1 ,W2,0 ,W2,1 ,,W2, N 1
15.x.1.5.1.2. CTC interleaver
The CTC interleaver requires the parameters P0, P1, P2, and P3 shown in Table 15.x.1-3 of which NEP set corresponds to
that in Table 15.x.1-2.
7
IEEE C802.16m-09/0510r2
The detailed interleaver structures except table for interleaver parameters correspond to 8.4.9.2.3.2.
Table 15.x.1-3. CTC Interleaver parameters
Index
NEP
P0
P1
P2
P3
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
48
64
72
80
88
96
104
120
128
136
144
152
160
176
184
192
200
208
216
232
240
248
256
264
272
288
296
304
312
320
328
344
352
360
368
376
384
400
416
432
440
456
472
480
496
5
11
11
7
13
13
7
11
13
13
11
11
13
17
13
7
11
11
11
11
13
13
11
13
13
17
13
13
11
17
17
17
17
17
19
13
11
19
17
17
19
17
19
13
17
0
12
18
4
36
24
4
30
46
58
6
38
68
52
2
58
76
10
54
70
60
6
64
72
82
74
0
130
32
84
148
160
106
40
88
110
96
142
102
126
48
184
40
120
194
0
0
0
32
36
0
8
0
44
4
0
12
76
68
0
48
0
32
56
60
0
84
8
68
44
72
84
112
124
108
160
116
56
132
0
92
48
0
132
92
20
0
104
60
0
0
12
18
36
32
24
48
34
30
58
6
74
64
32
2
10
24
42
2
58
60
46
8
8
38
2
64
46
108
132
76
52
50
128
172
14
144
142
178
74
144
48
28
180
58
Index
NEP
P0
P1
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
584
600
608
624
640
656
664
680
696
712
720
736
752
768
776
800
824
848
872
888
912
936
960
984
1000
1024
1048
1072
1096
1112
1136
1160
1184
1216
1248
1280
1312
1336
1368
1392
1424
1448
1480
1504
1536
21
31
74
12
20 214
272 28
P2
P3
23
23
23
23
288
286
84
24
244
220
296
300
140
70
236
52
23 272 220 60
19 48 240 144
31 252 216 48
25 214 180 286
23
29
23
29
130
126
26
252
156
208
24
0
238
270
230
88
29 100 196 140
216
150
29 130 332
23
42
29
150
234
388
82
29 408 300 316
25 414 84 414
29
14
264
94
25 272 168 400
53
62
12
2
31 142 40 342
29 290 148 446
29
320
236
324
27 424 212 416
35 290 228 390
23 178 392 430
33 38 244 550
37 170 276 134
31 314 348 222
31
31
31
29
31
2
368
88
152
214
568
584
404
8
160
94
524
608
24
506
39 2 168 646
29 570 348 574
31 218 484 446
31 676 124 184
33 254 372 158
31 32 716 736
31
31
254
34
8
416
564
474
710
Index
NEP
P0
P1
P2
P3
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
1752
1784
1824
1864
1896
1920
1952
2000
2048
2096
2144
2192
2232
2280
2328
2368
2432
2496
2560
2624
2752
2816
2880
2944
3008
3072
3200
3264
3328
3392
3456
3520
3648
3712
3776
3840
3904
3968
4096
4160
4224
4288
4352
4416
4544
31
33
314
886
656
888
666
518
41
774
548
898
33
35
504
936
444
940
664
832
43
35
318
94
556
144
778
686
37
290
692
638
31
2
332
622
39 400
29 298
39 1074
29 240
41 474
41 254
688
252
148
496
376
884
68
610
710
1100
814
1054
47
43
43
53
47
37
31
43
228
452
0
264
378
430
624
720
440
888
208
488
1092
880
704
360
724
96
528
824
1250
970
400
540
41
338
660
646
43
53
43
49
37
51
43
57
49
41
53
53
51
57
55
79
59
57
59
59
65
916
184
1382
142
258
460
170
776
132
1328
772
92
664
1296
148
214
14
662
2052
1342
1380
1136
824
632
828
28
56
920
1232
720
772
256
1124
200
760
808
308
668
1516
712
1968
1068
912
1368
1086
1354
1522
1608
1518
1012
276
1036
408
476
64
1360
308
262
1474
42
1804
1562
1036
IEEE C802.16m-09/0510r2
45
46
47
48
512
528
544
552
19
17
19
13
64
36
222
198
52
196
248
180
124
100
134
190
49
568
19
102
140
226
95
96
97
98
1560
1600
1640
1672
29 300 248 568
31
454
216
145
146
147
148
234
33 164 432 748
35 164 368 700
4 848 332
99 1712 41
4608
4672
4736
4800
67
67
59
53
954
410
2
66
1140
1020
956
24
1566
114
458
2
15.x.1.5.1.3. Determination of CTC circulation states
Correspond to 8.4.9.2.3.3.
15.x.1.5.1.4. Bit separation
Correspond to 8.4.9.2.3.4.1.
15.x.1.5.1.5. Subblock interleaving
The subblock interleaver requires the parameters m and J shown in Table 15.x.1-4 of which NEP set corresponds to that in
Table 15.x.1-2.
The detailed subblock interleaver structures except table for subblock interleaver parameters correspond to 8.4.9.2.3.4.2.
Table 15.x.1-4. The parameters for the subblock interleavers
Index
NEP
m
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
48
64
72
80
88
96
104
120
128
136
144
152
160
176
184
192
200
208
216
232
240
248
256
3
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
5
5
6
6
6
6
J
3
2
3
3
3
3
4
2
2
3
3
3
3
3
3
3
4
4
4
2
2
2
2
Index
NEP
m
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
328
344
352
360
368
376
384
400
416
432
440
456
472
480
496
512
528
544
552
568
584
600
608
6
6
6
6
6
6
6
6
6
6
6
7
7
7
7
7
7
7
7
7
7
7
7
J
Index
3
3
3
3
3
3
3
4
4
4
4
2
2
2
2
2
3
3
3
3
3
3
3
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
NEP
m
720
736
752
768
776
800
824
848
872
888
912
936
960
984
1000
1024
1048
1072
1096
1112
1136
1160
1184
7
7
7
7
7
7
7
7
7
7
8
8
8
8
8
8
8
8
8
8
8
8
8
9
J
Index
3
3
3
3
4
4
4
4
4
4
2
2
2
2
2
2
3
3
3
3
3
3
3
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
NEP
m
1424
1448
1480
1504
1536
1560
1600
1640
1672
1712
1752
1784
1824
1864
1896
1920
1952
2000
2048
2096
2144
2192
2232
8
8
8
8
8
8
8
8
8
8
8
8
9
9
9
9
9
9
9
9
9
9
9
J
Index
3
3
3
3
3
4
4
4
4
4
4
4
2
2
2
2
2
2
2
3
3
3
3
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
NEP
m
2752
2816
2880
2944
3008
3072
3200
3264
3328
3392
3456
3520
3648
3712
3776
3840
3904
3968
4096
4160
4224
4288
4352
9
9
9
9
9
9
9
9
9
9
9
9
10
10
10
10
10
10
10
10
10
10
10
J
3
3
3
3
3
3
4
4
4
4
4
4
2
2
2
2
2
2
2
3
3
3
3
IEEE C802.16m-09/0510r2
23
24
25
26
27
28
264
272
288
296
304
312
6
6
6
6
6
6
3
3
3
3
3
3
53
54
55
56
57
58
624
640
656
664
680
696
7
7
7
7
7
7
3
3
3
3
3
3
83
84
85
86
87
88
1216
1248
1280
1312
1336
1368
8
8
8
8
8
8
3
3
3
3
3
3
113
114
115
116
117
118
2280
2328
2368
2432
2496
2560
9
9
9
9
9
9
3
3
3
3
3
3
29
320
6
3
59
712
7
3
89
1392
8
3
119
2624
9
3
143
144
145
146
147
148
4416
4544
4608
4672
4736
4800
10
10
10
10
10
10
3
3
3
3
3
3
15.x.1.5.1.6. Bit grouping
Corresponding to section 8.4.9.2.3.4.3.
15.x.1.5.1.7. Resource segmentation
If KFB > 1, the NRE data resource elements allocated for the subpacket are segmented into KFB blocks, one for each FEC
block. The number of data resource elements for the k-th FEC block is defined by following equation.
N RE, k
 N RE


(
K

k

1
)
FB


 2  2
,
K
FB




0  k  K FB
15.x.1.5.1.8. Bit selection and repetition
Bit selection and repetition are performed to generate the subpacket.
Let NCTC, k be the number of coded bits that shall be transmitted for the k-th FEC block. The value of NCTC, k is calculated
by the following equation
N CTC, k  N RE, k  N SM  N mod .
The index in the HARQ buffer for the j-th bit transmitted for the k-th FEC block shall be:
uk, j  ( Pi,k  j ) mod N FB_Buffer, k , for k = 0, …, KFB – 1, and
j  0 ,...,N CTC, k  1 ,
where i is the subpacket ID of the subpacket (SPID = i), Pi,k is the starting position for subpacket i of the k-th FEC block
as specified in 15.x.2.1, and N FB_Buffer, k  3N FB, k is the buffer size for the k-th FEC block.
15.x.1.5.1.9. Bit collection
The selected bits from each FEC block are collected in the order of FEC block for the HARQ transmission.
10
IEEE C802.16m-09/0510r2
15.x.1.5.1.10.
Modulation
Correspond to 8.4.9.4.2.
15.x.2.
HARQ
15.x.2.1.
IR HARQ
HARQ IR is used in 802.16m by changing the starting position, Pi,k, of the bit selection for HARQ retransmissions.
For downlink HARQ, the starting point for the bit selection algorithm as described in section 15.x.1.5.1.8 is determined as
a function of SPID using Table 15.x.2-1 .
Table 15.x.2-1. Starting position determination for downlink HARQ
SPID
Starting position
0
P0, k  0
1
P1, k   N CTC, k mod N FB_Buffer, k
2
TBD
3
TBD
For uplink HARQ, the starting position for the bit selection algorithm as described in section 15.x.1.5.1.8 is determined as
a function of SPID for the following equation.
Pi , k  i  N CTC, k mod N FB_Buffer, k .
For uplink HARQ, subpackets shall be transmitted in sequential order. In other words, for the t-th transmission, the
subpacket ID shall be set to SPID = t mod 4.
15.x.2.1.1.1. Constellation Rearrangement
Two constellation re-arrangement versions shall be supported. Co-Re only applies to 16QAM and 64QAM. In case of
QPSK, it is transparent.
In one HARQ process, all transmissions/retransmissions use the same Co-Re scheme. In this particular Co-Re scheme,
two Co-Re versions are exploited for 16QAM and 64 QAM modulation respectively.
-------------------------------
Text End
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