![LTE Resource (Parameters)
DL/UL Parameters
Subcarrier Spacing ∆𝑓 = 15 𝑘𝐻𝑧 UL/DL, ∆𝑓∗
= 7.5 𝑘𝐻𝑧 DL only
Parameters used by Verizon in US
7/17
System BW [MHz] 1.4 3 5 10 15 20
# Resource Blocks 𝑵𝑹𝑩 6 15 25 50 75 100
FFT Size 𝑵
∆𝒇 = 𝟏𝟓𝑲𝑯𝒛 2048
∆𝒇 = 𝟕. 𝟓𝑲𝑯𝒛 - 4096*
# Subcarriers per RB 𝑵𝒔𝒄
∆𝒇 = 𝟏𝟓𝑲𝑯𝒛 12
∆𝒇 = 𝟕. 𝟓𝑲𝑯𝒛 - 24*
# Used Subcarriers 𝑵𝒖
∆𝒇 = 𝟏𝟓𝑲𝑯𝒛 72 180 300 600 900 1200
∆𝒇 = 𝟕. 𝟓𝑲𝑯𝒛 - 2400*
Sampling Rate [MHz] 30.72
(Reference : 3GPP TS 36.101 V8.15.0 (2011-09))](https://image.slidesharecdn.com/gwanmo0615121-240427162636-04c50308/85/Overview-of-AMC-LTE-feature-to-enhance-DL-user-througput-7-320.jpg)
![CQI Table
14/17
4-bit CQI Table
CQI Modulation Spectral Efficiency
0 Out of Range
1
QPSK
0.1523
2 0.2344
3 0.3770
4 0.6016
5 0.8770
6 1.1758
7
16 QAM
1.4766
8 1.9141
9 2.4063
10
64 QAM
2.7305
11 3.3223
12 3.9023
13 4.5234
14 5.1152
15 5.5547
Spectral Efficiency
Throughput
𝑇𝑟 = 𝛼 ⋅ 𝑆(𝑆𝑁𝑅)
𝑆 𝑆𝑁𝑅 = log2 1 + 𝑆𝑁𝑅 [bps/Hz]
𝛼 : Practical Attenuation Factor](https://image.slidesharecdn.com/gwanmo0615121-240427162636-04c50308/85/Overview-of-AMC-LTE-feature-to-enhance-DL-user-througput-14-320.jpg)
Overview of AMC LTE feature to enhance DL user througput.
- 1. Overview of AMC in LTE Gwanmo Ku Adaptive Signal Processing and Information Theory Research Group Jun. 15, 2012
- 2. Outline LTE Basic Why LTE LTE Network / Resources / Frame Structure LTE in US (Verizon) AMC in LTE Why AMC? Channel Condition : CQI Reporting MCS associated with CQI References 2/17
- 4. Why LTE? 4/17 Higher Data Rate QoS Packet Switch Optimized System Continuity of Competitiveness of 3G System High Spectral Efficiency Very Low Latency Support of Variable Bandwidth LTE (Reference: http://www.3gpp.org/LTE)
- 5. LTE Network 5/17 LTE Network Internet * EPC : Evolved Packet Core * E-UTRAN : Evolved Universal Terrestrial Radio Access Network * UE : User Equipment * eNB : evolved Node B
- 6. LTE Resource (Unit) 6/17 Physical Resource Block (PRB) The Smallest User Assignment Resource Unit (12 Sub-carriers) Frequency (#Subcarriers) Time (# Symbols) 180 KHz (12 Sub-carriers) 0.5 ms (6 or 7) PRB
- 7. LTE Resource (Parameters) DL/UL Parameters Subcarrier Spacing ∆𝑓 = 15 𝑘𝐻𝑧 UL/DL, ∆𝑓∗ = 7.5 𝑘𝐻𝑧 DL only Parameters used by Verizon in US 7/17 System BW [MHz] 1.4 3 5 10 15 20 # Resource Blocks 𝑵𝑹𝑩 6 15 25 50 75 100 FFT Size 𝑵 ∆𝒇 = 𝟏𝟓𝑲𝑯𝒛 2048 ∆𝒇 = 𝟕. 𝟓𝑲𝑯𝒛 - 4096* # Subcarriers per RB 𝑵𝒔𝒄 ∆𝒇 = 𝟏𝟓𝑲𝑯𝒛 12 ∆𝒇 = 𝟕. 𝟓𝑲𝑯𝒛 - 24* # Used Subcarriers 𝑵𝒖 ∆𝒇 = 𝟏𝟓𝑲𝑯𝒛 72 180 300 600 900 1200 ∆𝒇 = 𝟕. 𝟓𝑲𝑯𝒛 - 2400* Sampling Rate [MHz] 30.72 (Reference : 3GPP TS 36.101 V8.15.0 (2011-09))
- 8. LTE Frame Structure Frame Structure Type 1 : FDD Frame Structure Type 2 : TDD 8/17 5ms Switch 10ms Switch (Reference : 3GPP TS 36.211 V8.9.0 (2009-12))
- 9. LTE Service in US (Verizon) 9/17 LTE Operating Band (Verizon) BW 10 MHz, 600 Sub-carriers (50 PRBs) MHz 699 716 729 746 756 758 768 777 787 788 798 700 800 750 Band 13 Band 13 Verizon LTE Plan in US FCC Upper 700 MHz Block C FDD Uplink FDD Downlink E-UTRA LTE Band FCC Band in US C C 757 776
- 10. Adaptive Modulation & Coding 2/11
- 11. Why AMC? 11/17 Needs in Communication System Throughput User Data Rate User Low BER Resource Assignment Adaptive Modulation & Coding Higher Order Modulation Larger TBS Lower Order Modulation AMC & RM
- 12. Adaptive Modulation & Coding 12/17 Modulation Order & BER (without channel coding) Channel Coding : Better BER Rate Change by Rate Matching Better Data Rate BPSK QPSK 16QAM 64QAM Better Throughput / Data Rate Bad BER
- 13. Channel Condition 13/17 CQI Reporting Process eNB UE DL Reference Signals CQI Reporting Scheduling Information - Allocated Bands - MCS / TBS 4 bit CQI Indexing
- 14. CQI Table 14/17 4-bit CQI Table CQI Modulation Spectral Efficiency 0 Out of Range 1 QPSK 0.1523 2 0.2344 3 0.3770 4 0.6016 5 0.8770 6 1.1758 7 16 QAM 1.4766 8 1.9141 9 2.4063 10 64 QAM 2.7305 11 3.3223 12 3.9023 13 4.5234 14 5.1152 15 5.5547 Spectral Efficiency Throughput 𝑇𝑟 = 𝛼 ⋅ 𝑆(𝑆𝑁𝑅) 𝑆 𝑆𝑁𝑅 = log2 1 + 𝑆𝑁𝑅 [bps/Hz] 𝛼 : Practical Attenuation Factor
- 15. MCS associated with CQI 15/17 5-bit MCS MCS CQI Modulation Spectral Efficiency MCS CQI Modulation Spectral Efficiency 0 2 QPSK 0.2344 16 16QAM 2.5684 1 0.3057 17 64 QAM 2.5684 2 3 0.3770 18 10 2.7305 3 0.4893 19 3.0264 4 4 0.6016 20 11 3.3223 5 0.7393 21 3.6123 6 5 0.8770 22 12 3.9023 7 1.0264 23 4.2128 8 6 1.1758 24 13 4.5234 9 1.3262 25 4.8193 10 16 QAM 1.3262 26 14 5.1152 11 7 1.4766 27 5.3349 12 1.6953 28 15 5.5547 13 8 1.9141 29 QPSK Reserved 14 2.1602 30 16QAM 15 9 2.4063 31 64QAM
- 16. References 2/11
- 17. References • LTE related Webpages http://www.3gpp.org : 3GPP Standard Web http://www.fcc.gov/ : FCC http://wireless.fcc.gov/uls/ : FCC Band License Search • LTE Standard Docs. http://www.3gpp.org/ftp/Specs/latest/Rel-8/36_series/ 17/17