Frame Structures for Legacy-Support and Legacy-Support Disabled Modes IEEE 802.16 Presentation...
Transcript of Frame Structures for Legacy-Support and Legacy-Support Disabled Modes IEEE 802.16 Presentation...
Frame Structures for Legacy-Support and Legacy-Support Disabled Modes
IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number:
IEEE S802.16m-08/243Date Submitted:
2008-03-17Source:
Sungho Moon and Jin Sam Kwak Voice: +82-31-450-1852LG Electronics E-mail: [email protected], [email protected],
[email protected], [email protected]; [email protected] Chongli Liu, Mingyang Sun, Xin Chang, Sean McBeath Huawei Technologies CO., LTD .*<http://standards.ieee.org/faqs/affiliationFAQ.html>
Venue:Re : Proposed 802.16m Frame Structure Baseline Content Suitable for Use in the 802.16m SDD (C802.16m-08/118r1)
Base Contribution:IEEE C802.16m-08/243
Purpose:Proposed 802.16m Frame Structure Baseline Content Suitable for Use in the 802.16m SDD (C802.16m-08/118r1)
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Basic OFDM Parameters
• Considerations– Without physical layer impacts on the legacy system
– The same parameters : Sampling frequency, FFT sizes, and sub-carrier spacing
– Different parameter : CP length
Transmission Bandwidth (MHz) 5 10 20
Sampling Frequency (MHz) 5.6 11.2 22.4
FFT Size 512 1024 2048
Sub-Carrier Spacing (kHz) 10.94 10.94 10.94
Tu (us) 91.4 91.4 91.4
Usage Cyclic Prefix (CP) Ts (us)OFDM Symbols
per FrameIdle Time (us)
Legacy Support Mode / 16m MBS
Tg=1/8 Tu 91.4 + 11.42=102.82 48 64.64
Legacy Support-Disabled 16m Mode
Tg=1/16 Tu 91.4 + 5.71=97.11 51 47.39
Motivations of 1/16 Tu CP
• Wireless Channel Models
• CP Lengths of Other Systems– LTE : 4.69 us and 5.21 us in a sub-frame (7 % overhead)
– UMB : 6.51 us as a default CP length (6 % overhead)
– Reference system : 11.42 us (=1/8 Tu) (12.5 % overhead)
Channel Model Mean Delay Spread (ns) RMS Delay Spread (ns) Max. Delay Spread (us)
Pedestrian A 14.4 45 0.41
Pedestrian B 409.1 750 3.7
Vehicular A 254.4 370.4 2.51
TU 6-ray Model 705 1070 5
Normal CP Lengths
• Normal CP Length For Legacy-Support Mode– The same as that of the reference system, i.e., 11.42 us which is 1/8 of an
OFDM symbol (Tu)
• Normal CP length For Legacy-Support Disabled Mode– A CP length of 1/16 Tu – Proper size to support ordinary channel conditions without loss in
spectral efficiency
• Advantages of the CP Length of 1/16 Tu (= 5.71 us)– Less than 10% CP overhead loss– 51 OFDM symbols per frame = Better spectral efficiency ( ~6%)– Additional gain from appropriate usages of the 3 OFDM symbols, e.g., preamble,
midamble, control, sounding, and etc.
• Other Short or Long CP Lengths– Can be considered for extraordinary cases
Basic Frame Structure
SU0
F0
Super-Frame Based Control Signaling
SU1 SU2 SU4
Super-Frame : 20 ms
F1 F2 F4
...
Frame : 5 ms
SF0 SF1 SF2 SF3 SF4 SF5 SF6 SF7
S0
S1
S2
S3
S4
S5
Sub-frame
OFDM Symbol
S0
S1
S2
S3
S4
S5
S6
S0
S1
S2
S3
S4
1) Type-1 Sub-Frame :6 Symbols
2) Type-2 Sub-Frame : 5 Symbols
3) Type-3 Sub-Frame : 7 Symbols
One-Symbol Punctured in Type-1
One-Symbol Added in Type-1
Frame Structure for Legacy-Support Mode
802.16m TDD Frame : 5 ms
DLSF0 (6)
DLSF1 (6)
DLSF2 (6)
DLSF3 (6)
DLSF4(5)
ULSF5 (6)
ULSF6 (6)
ULSF7 (6)
DL
Legacy TDD Frame : 5 ms
UL
RTG TTG
S0
S1
S2
S3
S4
S5
Type-1 Sub-frame
S0
S1
S2
S3
S4
Type-2 Sub-frame
102.82 us
6 OFDM Symbols = 0.617 ms 5 OFDM Symbols = 0.514 ms
802.16m FDD Frame : 5 ms
DL/ULSF0 (6)
DL/ULSF1 (6)
DL/ULSF2 (6)
DL/ULSF3 (6)
DL/ULSF4 (6)
DL/ULSF5 (6)
DL/ULSF6 (6)
DL/ULSF7 (6)
Idle
102.82 us
29 OFDM Symbols 18 OFDM Symbols
For TTG/RTG
Frame Structure for Legacy-Support Disabled Mode
802.16m TDD Frame : 5 ms
DLSF0 (7)
DLSF1 (6)
DLSF2 (6)
DLSF3 (6)
DLSF4 (6)
ULSF5 (6)
ULSF6 (6)
ULSF7 (7)
DL UL
RTGTTG
S0
S1
S2
S3
S4
S5
Type-1 Sub-frame
S0
S1
S2
S3
S4
Type-3 Sub-frame
97.11 us
6 OFDM Symbols = 0.583 ms 7 OFDM Symbols = 0.680 ms
802.16m FDD Frame : 5 ms
S5
DL/ULSF0 (7)
DL/ULSF1 (6)
DL/ULSF2 (6)
DL/ULSF3 (6)
DL/ULSF4 (7)
DL/ULSF5 (6)
DL/ULSF6 (6)
DL/ULSF7 (7)
Idle
97.11 us
TTG
Legacy TDD Frame : 5 ms
29 OFDM Symbols 18 OFDM Symbols
S6
Coexistence Btw. Legacy-Support and Legacy-Support Disabled Modes
(7:1)TTG:107.46
802.16m in Legacy-Support Mode (Tg = 1/8 Tu)
3010.41
DL(7)
3094.91
DL DL DL DL
TTG:84.5
3593.07
DLDL(7)
DL DL DL DL
3677.57
TTG:84.5
4175.73
DL DL
RTG : 60.0
DL(7)
DL DL DL DL
4260.23
UL(7)
TTG:84.5
DL(7)
2427.8
DL: UL = 4:4 DL DL DL
2511.6
TTG:84.5
DL: UL = 5:3
DL: UL = 6:2
DL: UL = 7:1
(6:2)TTG:107.46(5:3)
TTG:107.46
(4:4) TTG:107.46
UL ULUL(7)
UL(7)
UL
UL(7)
UL
UL
UL
RTG : 60.0
RTG : 60.0
RTG : 60.0
RTG : 60.0
5000 (us)
Proposed Structure for Legacy-Support Disabled Mode
Sub-Frame Type Type-1 Type-2 Type-3
CP Length DL:UL Sub-Frame Index
1/8 Tu
(4:4) 0, 1, 2, 4, 5, 6, and 7 3 N/A
(5:3) 0, 1, 2, 3, 5, 6, and 7 4 N/A
(6:2) 0, 1, 2, 3, 4, 6, and 7 5 N/A
(7:1) 0, 1, 2, 3, 4, 5, and 7 6 N/A
1/16 Tu
(4:4) 1, 2, 3, 4, 5, and 6 N/A 0 and 7
(5:3) 1, 2, 3, 4, 5, and 6 N/A 0 and 7
(6:2) 1, 2, 3, 4, 5, and 6 N/A 0 and 7
(7:1) 1, 2, 3, 4, 5, and 6 N/A 0 and 7
• Advantages– Increased spectral efficiency (6%)
– No problem to coexist with 16m systems operating with a 1/8 CP length– Commonality with structures of a CP length of 1/8 Tu,
• Number of sub-frames per frame, i.e., 8 sub-frame per frame
• Number of OFDM symbols per sub-frame, e.g., 5, 6, and 7 OFDM symbols per sub-frame
• Unified TDD Configuration for Both CP Cases
Proposed Text on C802.16m/118r1
11.3 OFDM Parameters[Add a CP length option into Table 11.3-1 (proposal-1) in C802.16m-08/118r1 as follows:]
Nominal Channel Bandwidth (MHz) 5 7 8.75 10 20
Over-sampling Factor 28/25 8/7 8/7 28/25 28/25
Sampling Frequency (MHz) 5.6 8 10 11.2 22.4
FFT Size 512 1024 1024 1024 2048
Sub-Carrier Spacing (kHz) 10.94 7.81 9.77 10.94 10.94
Tu (us) 91.4 128 102.4 91.4 91.4
Cyclic Prefix (CP) Ts (us) Number of OFDM Symbols per Frame Idle Time (us)
Tg=1/8 Tu
91.4 + 11.42=102.82 (for
5, 10, 20 MHz)48 (for 5, 10, 20 MHz) 64.64
128+16=144 (for 7 MHz)
34 (for 7 MHz) 104
102.4+12.8=115.2 (for 8.75 MHz)
43 (for 8.75 MHz) 46.40
Tg = 1/16 Tu 91.4 + 5.71 = 97.11 (for 5, 10, 20 MHz)
51 (for 5, 10, 20 MHz) 47.39
[Table 11.3-1: OFDM parameters for IEEE 802.16m] proposal-1
* Other CP, e.g., 1/32 Tu or 1/4 Tu, can be considered in the 16m numerology.
Proposed Text on C802.16m/118r1 (cont’d)11.4.1 Basic Frame Structure (proposal-1)[Replace Figure 11.4-1 (proposal-1) in C802.16m-08/118r1 with the following figure]
SU0
F0
Super-Frame Based Control Signaling
SU1 SU2 SU4
Super-Frame : 20 ms
F1 F2 F4
...
Frame : 5 ms
SF0 SF1 SF2 SF3 SF4 SF5 SF6 SF7
S0
S1
S2
S3
S4
S5
Sub-frame
OFDM Symbol
S0
S1
S2
S3
S4
S5
S6
S0
S1
S2
S3
S4
1) Type-1 Sub-Frame :6 Symbols
2) Type-2 Sub-Frame : 5 Symbols
3) Type-3 Sub-Frame : 7 Symbols
One-Symbol Punctured in Type-1
One-Symbol Added in Type-1
Figure 11.4-1: Basic frame structure
Proposed Text on C802.16m/118r1 (cont’d)
[Replace Figure 11.4-2 (option1) in C802.16m-08/118r1 with the following figure]
802.16m TDD Frame : 5 ms
DLSF0 (6)
DLSF1 (6)
DLSF2 (6)
DLSF3 (6)
DLSF4(5)
ULSF5 (6)
ULSF6 (6)
ULSF7 (6)
DL
Legacy TDD Frame : 5 ms
UL
RTG TTG
S0
S1
S2
S3
S4
S5
Type-1 Sub-frame
S0
S1
S2
S3
S4
Type-2 Sub-frame
102.82 us
6 OFDM Symbols = 0.617 ms 5 OFDM Symbols = 0.514 ms
802.16m FDD Frame : 5 ms
DL/ULSF0 (6)
DL/ULSF1 (6)
DL/ULSF2 (6)
DL/ULSF3 (6)
DL/ULSF4 (6)
DL/ULSF5 (6)
DL/ULSF6 (6)
DL/ULSF7 (6)
Idle
102.82 us
29 OFDM Symbols 18 OFDM Symbols
For TTG/RTG
Figure 11.4-2 : TDD and FDD Frame Structures with a CP of 1/8 Tu (DL to UL ratio of 5:3)
Proposed Text on C802.16m/118r1 (cont’d)
[Replace Figure 11.4-3 (option1) in C802.16m-08/118r1 with the following figure]
Figure 11.4-3: TDD and FDD Frame Structure with a CP of 1/16 Tu (DL to UL ratio of 5:3)
802.16m TDD Frame : 5 ms
DLSF0 (7)
DLSF1 (6)
DLSF2 (6)
DLSF3 (6)
DLSF4 (6)
ULSF5 (6)
ULSF6 (6)
ULSF7 (7)
DL UL
RTGTTG
S0
S1
S2
S3
S4
S5
Type-1 Sub-frame
S0
S1
S2
S3
S4
Type-3 Sub-frame
97.11 us
6 OFDM Symbols = 0.583 ms 7 OFDM Symbols = 0.680 ms
802.16m FDD Frame : 5 ms
S5
DL/ULSF0 (7)
DL/ULSF1 (6)
DL/ULSF2 (6)
DL/ULSF3 (6)
DL/ULSF4 (7)
DL/ULSF5 (6)
DL/ULSF6 (6)
DL/ULSF7 (7)
Idle
97.11 us
TTG
Legacy TDD Frame : 5 ms
29 OFDM Symbols 18 OFDM Symbols
S6