Overview of AMC in LTE - Electrical and Computer Engineering

1 Overview of AMC in LTE Gwanmo Ku Adaptive Signal Processing and Information Theory Research Group Jun. 15, 2012 OutlineLTE 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 LTE Basic2/11 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: ) 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 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) ms (6 or 7) PRB LTE Resource (Parameters)DL/UL Parameters Subcarrier Spacing =15 UL/DL, = DL only Parameters used by Verizon in US 7/17 System BW [MHz] 3 5 10 15 20 # Resource Blocks 6 15 25 50 75 100 FFT Size = 2048 =.

2 - 4096* # Subcarriers per RB = 12 = . - 24* # Used Subcarriers = 72 180 300 600 900 1200 = . - 2400* Sampling Rate [MHz] (Reference : 3 GPP TS (2011-09)) LTE Frame StructureFrame Structure Type 1 : FDD Frame Structure Type 2 : TDD 8/17 5ms Switch 10ms Switch (Reference : 3 GPP TS (2009-12)) 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 Adaptive Modulation & Coding2/11 Why AMC?

3 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 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 16 QAM 64 QAM Better Throughput / Data Rate Bad BER Channel Condition 13/17 CQI Reporting Process eNB UE DL Reference Signals CQI Reporting Scheduling Information -Allocated Bands -MCS / TBS 4 bit CQI Indexing CQI Table 14/17 4-bit CQI Table CQI Modulation Spectral Efficiency 0 Out of Range 1 QPSK 2 3 4 5 6 7 16 QAM 8 9 10 64 QAM 11 12 13 14 15 Spectral Efficiency Throughput = ( ) =log21+ [bps/Hz] : Practical Attenuation Factor MCS associated with CQI 15/17 5-bit MCS MCS CQI Modulation Spectral Efficiency MCS CQI Modulation Spectral Efficiency 0 2 QPSK 16 16 QAM 1 17 64 QAM 2 3 18 10 3 19 4 4 20 11 5 21 6 5 22 12 7 23 8 6 24 13 9 25 10 16 QAM 26 14 11 7 27 12 28 15 13 8 29 QPSK Reserved 14 30 16 QAM 15 9 31 64 QAM References2/11 References LTE related Webpages : 3 GPP Standard Web : FCC : FCC Band License Search LTE Standard Docs.

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