Overview of AMC in LTE

17 Pages·2012·1.17 MB·English

Overview of AMC in LTE
Gwanmo Ku
Adaptive Signal Processing and Information Theory Research Group
Jun. 15, 2012
Outline
2/17
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
2/11
LTE Basic
Why LTE?
4/17

Continuity of
Packet Switch
Higher Data Rate
Competitiveness
Optimized System
QoS
of 3G System

LTE

High Spectral Efficiency
Very Low Latency
Support of Variable Bandwidth
(Reference: http://www.3gpp.org/LTE)
LTE Network
5/17
 L TE 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
 P hysical Resource Block (PRB)
 The Smallest User Assignment Resource Unit (12 Sub-carriers)

Frequency
(#Subcarriers)

180 KHz
PRB
(12 Sub-carriers)
0.5 ms
Time
(6 or 7)
(# Symbols)
LTE Resource (Parameters)
7/17
DL/UL Parameters
System BW [MHz] 1.4 3 5 10 15 20
# Resource Blocks 𝑵 6 15 25 50 75 100
𝑹𝑩

∆𝒇=𝟏𝟓𝑲𝑯𝒛 2048
FFT Size 𝑵
∆𝒇=𝟕.𝟓𝑲𝑯𝒛 - 4096*
∆𝒇=𝟏𝟓𝑲𝑯𝒛 12
# Subcarriers per RB 𝑵
𝒔𝒄
∆𝒇=𝟕.𝟓𝑲𝑯𝒛 - 24*

∆𝒇=𝟏𝟓𝑲𝑯𝒛 72 180 300 600 900 1200
# Use d Subcarriers 𝑵
𝒖
∆𝒇=𝟕.𝟓𝑲𝑯𝒛 - 2400*

Sampling Rate [MHz] 30.72

Subcarrier Spacing ∆𝑓 = 15 𝑘𝐻𝑧 UL/DL, ∆𝑓∗ = 7.5 𝑘𝐻𝑧 DL only
Parameters used by Verizon in US
(Reference : 3GPP TS 36.101 V8.15.0 (2011-09))
LTE Frame Structure
8/17
Frame Structure Type 1 : FDD

Frame Structure Type 2 : TDD

5ms
Switch
10ms
Switch
(Reference : 3GPP TS 36.211 V8.9.0 (2009-12))
LTE Service in US (Verizon)
9/17
 L TE Operating Band (Verizon)
FDD Uplink FDD Downlink

E-UTRA LTE Band
700 800
750
MHz 699 716 729 746 756 758 768 777 787 788 798

Band 13 Band 13

757 776
C C

Verizon LTE Plan in US
FCC Upper 700 MHz Block C

FCC Band in US
 BW 10 MHz, 600 Sub-carriers (50 PRBs)
2/11
Adaptive Modulation & Coding