1. LTE-A : 4G Wireless Broadband Networks
中山大學 電機系
許蒼嶺教授

3. 行動通信標準演進

4. Evolution of Wireless Access Technologies
4G Air Interfaces
CDMA
2000-1X
HRPDA 1x
EVDO
1x EVDV
Rel. C
Rel. D
Wide Area
Mobile
3GPP2
MOBILE BROADBAND
GSM
GPRS
EDGE
UMTS
HSPA
LTE
3GPP
802.16e
(Mobile WIMAX)
Mobile Industry
Coverage/Mobility
Metro Area
Nomadic
802.16a/d
(Fixed NLOS)
Fixed Wireless Industry
802.11n
(smart antennas)
802.11
Mesh extns.
802.16
(Fixed LOS)
Dial Up
DSL Experience
Local Area
Fixed
Data Rates (kbps)
802.11b/a/g
100,000 +
Higher Data Rate / Lower Cost per Bit

5. 3GPP

6. 3GPP Radio Access Milestones

8. Operator’s Service Stack
IMS
Layer
Application services
Mobility, Policy and
Administration Services
EPC
Core network
Access technologies
connection gateways
Access
Technologies
WiMAX
LTE
DSLAM
WiFi
Devices

9. Population penetration of mobile, fixed and broadband across Asia-Pacific

10. TDMA/OFDM/OFDMA

13. Modulations & Channel Size
Uplink Mandarory US
European
Downlink Mandarory
Access Range:
QPSK > QAM-16 > QAM-64
Data Rate:
QAM-64 > QAM-16 > QPSK

14. Frame Durations
with TDD Frame Structure
0.5/1/2 ms

15. Number of PS in 16-QAM Frame duration = 1 ms
Signal (Baud) rate = 16 Mbauds/sec
4 bits in a signal (baud) using 16-QAM
Ts=LT, Data rate, R = LS = 4 x16 = 64 Mbps
Number of PS (Physical Slot)
(64 Mbps x 1 ms) / 16 bits = 4000
Assume every PS = 16 bits

16. 4G: LTE-A vs IEEE 802.16m ITU-R’s IMT-Advanced (4G) requirements
up to 1 Gbps in static or low mobility environment
up to 100 Mbps in high-speed mobile environment
Multicarrier is the technology to utilize wider bandwidth for parallel data transmission across multiple RF carriers.
IEEE m
LTE-A
Carrier Aggregation (CA)
Component Carrier (CC)

18. IEEE 802.16m OFDMA Parameters
Nominal Channel Bandwidth (MHz) 5 7
8.75 10 20
Over-sampling Factor
28/25
8/7
Sampling Frequency (MHz)
5.6 8
11.2
22.4
FFT Size
512
1024
2048
Sub-Carrier Spacing (kHz)
Useful Symbol Time Tu (μs)
91.429
128
102.4
Cyclic Prefix (CP)
Tg=1/8 Tu
Symbol Time Ts (μs)
144
115.2
FDD
No. of OFDM
symbols per Frame 48 34 43
Idle time (μs)
62.857
104
46.40
TDD 47 33 42
TTG + RTG (μs)
248
161.6
Tg=1/16 Tu
Symbol Time Ts(μs)
97.143
136
108.8 51 36 45
45.71 50 35 44
240
212.8
Number of used subcarriers
433
865
1729

19. 802.16m Guard Bands

20. Baud Rate B: baud rate, number of symbols in one second
S: number of symbols in an OFDMA frame
T: OFDMA frame duration
N: number of carriers in an OFDMA frame
B = ( ) x N

21. Data Rate vs Baud Rate R: data rate (bps)
M: number of different signal elements in MCS
B: baud rate, number of symbols in one second
R = B x

22. LTE Frame Structure Assume total BW = 30 Mhz and 64-QAM
One sub-carrier = 15 Khz
Total sub-carriers = 30 MHz/15 Khz
= 2000 sub-carriers
Total capacity (Data rate)
= 2000 x symbols/sec x 6 bits/symbol
= 168 Mbps
One OFDMA frame (10 msec) = 10 sub-frames
One sub-frame (1 msec) = 2 slots
One slot (0.5 msec) = 7 symbols
Symbol rate = 7/0.5 msec = symbols/sec
One RE = One symbol x one sub-carrier One RB = 7 symbols x N sub-carriers

24. Frame time = 5 msec , Number of carriers = 192
Frame time = 5 msec , Number of carriers = 192
Data Rate = (360/5 msec)x192= Mbps

25. LTE-A
Enhanced Multicast Broadcast Service (EMBS)

26. Channel Coding Systematic bits Turbo coding 1/3 Systematic bits
Parity bits
Mapping to the circular buffer
Systematic bits
Parity bits

27. 不同重傳次數的HARQ封包 RV=0 RV=1 RV=2 RV=3 Coding rate=3/4 1st transmission
Systematic bits
Parity bits
1st transmission
2nd transmission
3rd transmission
4th transmission
Coding rate=3/4

28. HARQ在Uplink的運作流程 + 1st transmission 2nd transmission 3rd transmission
ERROR MN
NACK BS
ACK
success
ERROR
1st transmission
2nd transmission ||
3rd transmission +
4th transmission
MN’s HARQ buffer
BS’s HARQ buffer

29. LTE-A: E-MBS Deployment with Broadcast Only and Mixed Carrier

30. LTE-A: Carrier Types From the perspective of an advanced MS (AMS)
Primary carriers
exchanges traffic and control signals with an advanced BS (ABS)
mobility, state, and context
Secondary carriers
An ABS can additionally assign secondary carrier(s) to an AMS
Controlled by the ABS through the primary carrier

31. LTE-A: Carrier Types From the perspective of an ABS
Fully configured carrier
carrying all control channels
synchronization, broadcast, multicast, and unicast control channels
both single-carrier and multicarrier AMSs can be served
Partially configured carrier
primarily to support downlink only transmission
only for frequency-division duplex (FDD) deployment
a dedicated EMBS carrier is one example

32. Multicarrier Frame Structure (LTE-A and WiMAX 802.16m)
An example of multicarrier frame structure with legacy support.

33. Multicarrier Transceiver Architectures (LTE-A)
Basic concept of subcarrier alignment.

34. Multicarrier Transceiver Architectures (LTE-A)
Different types of AMS transceiver architecture for multicarrier aggregation.

35. Network entry procedure for multicarrier support.
Network Entry (LTE-A)
Network entry procedure for multicarrier support.
AAI: Advanced Air Interface
AAI_REG-REQ: 3 bits

36. Activation and Deactivation of Assigned Carriers (LTE-A)
Multilevel carrier management scheme.

37. Handover (LTE-A)

38. Relay Related Connections

39. Fractional Frequency Reuse (FFR) for Directional Antenna

40. CA Scenarios and Component Carrier (CC) Types (LTE-A)
Example of carrier aggregation scenarios:
a) contiguous aggregation of five component carriers with equal bandwidth
b) non-contiguous aggregation of component carriers with different bandwidths

41. Primary and Secondary CCs (LTE-A)
UE served bPCell/SCell configuration for different y the same eNB